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10,885,272 | ACCEPTED | METHOD FOR DECONVOLUTION OF IMPEDANCE SPECTRA | A method for deconvoluting a time dependent impedance spectrum and using the deconvoluted time dependent impedance spectrum as an indicator of the performance condition of a working fluid is disclosed. Also disclosed is a method to determine the viscosity ratio of a working fluid using the resistance ratio obtained from frequency dependent impedance data. | 1. A method to deconvolute a time dependent impedance spectrum of a lubricant oil comprising: obtaining a time dependent impedance spectrum of the lubricant oil over a time range and at a plurality of time intervals wherein the time dependent impedance spectrum comprises at least one peak, measuring at least one lubricant property over said time range and said plurality of time intervals to provide at least one time dependent lubricant property spectrum wherein the time dependent lubricant property spectrum comprises at least one peak, comparing said obtained time dependent impedance spectrum with said measured time dependent lubricant property spectra, where the peaks of each coincide in time, assigning to the peaks on the time dependent impedance spectrum the lubricant property of said measured coinciding time dependent lubricant properties, resulting in a deconvoluted time dependent impedance spectrum. 2. The method of claim 1 wherein said impedance spectrum is measured in the frequency range between 1 and 30,000 Hz. 3. The method of claim 1 wherein the impedance spectrum is measured at more than 2 frequencies to provide a series of time dependent impedance spectra. 4. The method of claim 1 wherein the impedance spectrum and the lubricant properties are measured at temperatures in the range of 50° C. to 150° C. 5. The method of claim 1 wherein said impedance spectrum and lubricant properties are measured on-line the machinery containing the lubricant oil. 6. The method of claim 1 wherein said impedance spectrum and lubricant properties are measured over a time range of 1 day to 10 years. 7. The method of claim 1 wherein said impedance spectrum and lubricant properties are determined at a time interval in the range of about 12 hours to about lyear. 8. The method of claim 1 wherein said lubricant properties are selected from the group consisting of lubricant additive degradation, lubricant base oil oxidation, lubricant temperature change, water concentration, lubricant viscosity, lubricant color and combinations thereof. 9. A method to use a time dependent spectrum as an indicator of the performance condition of a lubricant oil comprising: obtaining a time dependent spectrum of the lubricant oil over a time range and at a plurality of time intervals, wherein said spectrum comprises at least one peak and said spectrum is selected from the group consisting of impedance spectrum, admittance spectrum, resistance spectrum, capacitance spectrum, phase angle spectrum and dielectric spectrum, measuring at least one lubricant property over said time range and at said plurality of time intervals to provide at least one time dependent lubricant property spectrum having at least one peak, comparing said obtained time dependent spectrum with said measured time dependent lubricant property spectrum, where the peaks of each coincide in time, assigning to the peaks on the time dependent spectrum the lubricant property of said measured coinciding time dependent lubricant properties whereby the time dependent spectrum is used an indicator of the measured lubricant property, and where the peaks of each do not coincide in time, the time dependent spectrum is used as an indicator of reduced performance condition of the lubricant oil. 10. The method of claim 9 wherein said time dependent spectrum is measured in the frequency range between 1 and 30,000 Hz. 11. The method of claim 9 wherein said time dependent spectrum is measured at more than 2 frequencies to provide a series of time dependent spectra. 12. The method of claim 9 wherein said time dependent spectrum and the lubricant properties are measured at temperatures in the range of 50° C. to 150° C. 13. The method of claim 9 wherein said time dependent spectrum and lubricant properties are measured on-line the machinery containing the lubricant oil. 14. The method of claim 9 wherein said time dependent spectrum and lubricant properties are measured over a time range of 1 day to 10 years. 15. The method of claim 9 wherein said time dependent spectrum and lubricant properties are measured at a time interval in the range of about 12 hours to about lyear. 16. The method of claim 9 wherein said lubricant properties are selected from the group consisting of lubricant additive degradation, lubricant base oil oxidation, lubricant temperature change, water concentration, lubricant viscosity and combinations thereof. 17. A method to determine the viscosity ratio of a lubricating oil in a machinery comprising: measuring frequency dependent impedance data for the lubricating oil over a range of frequencies and over a time range, determining the resistance (R) of the lubricating fluid using a Nyquist plot, at starting time t=0 and a particular time, t within said time range, and denoting the resistance at time t=0 as Ro and the resistance at time t as Rt, calculating a resistance ratio RR=Rt/Ro, measuring the absorbance (A) of the lubricating oil at said time, t at a wavelength in the range of 500 to 1050 nm, calculating the value of {RR+C1+C2(A−C3)}/C4 where C1, C2 and C3 are numbers whose absolute values range from 0 to 10,000, and C4 is a number whose absolute value ranges from 0.005 to 10,000, said determined value being the viscosity ratio of the lubricating oil. 18. The method of claim 17 wherein said frequency dependent impedance data is measured in the frequency range between 1 and 10,000 Hz. 19. The method of claim 17 wherein said frequency dependent impedance data is measured at more than 2 frequencies to provide a series of frequency dependent spectra. 20. The method of claim 17 wherein said frequency dependent impedance data and absorbance are measured at temperatures in the range of 50° C. to 150° C. 21. The method of claim 17 wherein said frequency dependent impedance data and absorbance are measured on-line the machinery containing the lubricant oil. 22. The method of claim 17 wherein said frequency dependent impedance data and absorbance are measured over a time range of 1 day to 10 years. 23. The method of claim 17 wherein said frequency dependent impedance data and absorbance are measured at a time interval in the range of about12 hours to about 1 year. 24. The method of claim 17 wherein said absorbance is measured at a wavelength in the range of 750 nm to 975 nm. | This application claims the benefit of U.S. Provisional application 60/494,485 filed Aug. 12, 2003. BACKGROUND OF THE INVENTION The present invention is broadly concerned with deconvolution of impedance spectra of a working fluid. The invention is also concerned with using deconvoluted impedance spectra as an indicator of the performance condition of a working fluid. SUMMARY OF THE INVENTION Working fluids, such as lubricating oils and hydraulic fluids, are important components of a wide variety of mechanical systems in which they provide one or more functions such as lubricating moving parts, transferring force or energy on the mechanical system, protecting parts against wear or even a combination of these. These fluids typically consist of hydrocarbon base oil formulated with numerous performance additives selected to enhance one or more performance characteristics of the fluid. With use over time these fluids may become contaminated with substances with which they come into contact, by the ingress of foreign substances in the mechanical system, by oxidation of the base oil and chemical decomposition of the additives used in the formulated fluids. The net result is a decrease in the performance characteristics of the fluid with the concomitant negative impact on the mechanical system using the fluid. Therefore, in many industrial environments regular fluid analysis by common laboratory methods is a standard modus operandi. This necessitates obtaining a sample of the fluid and transporting it, typically off-site, for analysis. This procedure normally takes at least three full days before the requisite analysis is completed and a report can be obtained. Such a time lag is highly undesirable. Many proposed methods for the on-line evaluation of the quality of lubricants are based on electrical measurements, such as the dielectric constant or impedance of the fluid, with the measurements being taken at one fixed frequency or a multiplicity of frequencies. Since the best frequency for optimum sensitivity often depends on the properties or operational conditions of the working fluid it is preferred to make impedance measurements at a multiplicity of frequencies. One subset of impedance measurements is dielectric measurements. Data obtained from time dependent impedance measurements are generally extremely complicated or convoluted. Additive degradation, base oil oxidation, temperature change, water and other polar species contamination, and viscosity changes of the lubricant oil can impact impedance properties of a lubricant oil. A method to deconvolute time dependent impedance spectra is needed so that the deconvoluted time dependent impedance spectra can provide information about the lubricant. One object of the present invention is to provide a method for deconvolution of time dependent impedance spectra. Another object of the present invention is to provide a method to utilize deconvoluted time dependent impedance spectra as an indicator of the performance condition of a fluid. Yet another object of the invention is a method to determine the viscosity ratio of a fluid by measuring frequency dependent impedance spectra. These and other objects will become apparent from the description, which follows. In one embodiment of the invention is a method to deconvolute a complex time dependent impedance spectrum of a lubricant oil comprising: obtaining a time dependent impedance spectrum of the lubricant oil over a time range and at a plurality of time intervals wherein the time dependent impedance spectrum comprises at least one peak, measuring at least one lubricant property over said time range and said plurality of time intervals to provide at least one time dependent lubricant property spectrum wherein the time dependent lubricant property spectrum comprises at least one peak, comparing said obtained time dependent impedance spectrum with said measured time dependent lubricant property spectra, where the peaks of each coincide in time, assigning to the peaks on the time dependent impedance spectrum the lubricant property of said measured coinciding time dependent lubricant properties, resulting in a deconvoluted time dependent impedance spectrum. In another embodiment of the invention is a method to use a time dependent spectrum as an indicator of the performance condition of a lubricant oil comprising: obtaining a time dependent spectrum of the lubricant oil over a time range and at a plurality of time intervals, wherein said spectrum comprises at least one peak and said spectrum is selected from the group consisting of impedance spectrum, admittance spectrum, resistance spectrum, capacitance spectrum, phase angle spectrum and dielectric spectrum, measuring at least one lubricant property over said time range and at said plurality of time intervals to provide at least one time dependent lubricant property spectrum having at least one peak, comparing said obtained time dependent spectrum with said measured time dependent lubricant property spectrum, where the peaks of each coincide in time, assigning to the peaks on the time dependent spectrum the lubricant property of said measured coinciding time dependent lubricant properties whereby the time dependent spectrum is used an indicator of the measured lubricant property, and where the peaks of each do not coincide in time the time dependent spectrum is used as an indicator of reduced performance condition of the lubricant oil. In yet another embodiment of the invention is a method to determine the viscosity ratio (VR) of a lubricating oil in a machinery comprising: measuring frequency dependent impedance data for the lubricating oil over a range of frequencies and over a time range, determining the resistance (R) of the lubricating fluid using a Nyquist plot, at starting time t=0 and a particular time, t within said time range, and denoting the resistance at time t=0 as Ro and the resistance at time t as Rt, calculating a resistance ratio RR=Rt/Ro, measuring the absorbance (A) of the lubricating oil at said time, t at a wavelength in the range of 500 to 1050 nm, calculating the value of {RR+C1+C2(A−C3)}/C4 where C1, C2 and C3 are numbers whose absolute values range from 0 to 10,000, and C4 is a number whose absolute values range from 0.005 to 10,000, said determined value being the viscosity ratio (VR) of the lubricating oil. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic illustration of a system for monitoring the condition of a working fluid according to the invention. FIG. 2 is a series of Nyquist plots for a paper machine lubricant. The Y axis is the negative of the imaginary part of impedance, Z″ and the x axis is the real part of impedance, Z′. FIG. 3 is a set of experimental data on a machine oil. Curve A is a time dependent dielectric spectrum. Time (in hours) is plotted on the x-axis and the dielectric constant is plotted on the y-axis. Also included in FIG. 3 are water (curve B) and temperature (curve C) time dependent spectra. Relative humidity (water) and temperature are plotted as a function of time on the same x-axis (time in hours). FIG. 4 is a regression plot of calculated viscosity ratio versus measured viscosity ratio for a lubricant oil. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS AC (alternating current) electro-impedance spectroscopy is a well-known technique. It involves the imposition of AC signals over a broad range of frequencies to a material to be analyzed. The electrical response to those signals is determined and by the application of electric circuit theory a description of the properties of the material is obtained. AC electro-impedance spectroscopy can be used to determine the conditions of a working fluid, particularly the conditions of low conductivity oils. Examples of low conductivity oils are oils that have a kinematic viscosity at 100° C. of greater than 15 cSt and containing less than about 3 wt % (active basis) of additives selected from dispersants, antioxidants, detergents, VI improvers and antiwear agents. AC electro-impedance spectroscopic methods can also be used for determining the condition of industrial oils, especially on-line, i.e., when contained in mechanical systems, even when the systems are operating. Non-limiting examples of working fluids are fluids such as paper machine lubricating oil and turbine oil. Typically AC electro-impedance spectra of a fluid can be measured when a pair of spaced apart electrodes, such as concentric, cylindrical electrodes, are placed in a body of working fluid to be analyzed. Preferably the working fluid is within a mechanical system, for example in an oil reservoir or sump of a mechanical system, in an oil delivery manifold, or bypass manifold of a mechanical system requiring lubrication or use of a working fluid. The dimensions of the electrode, of course, will depend on its positioning within the mechanical system and the nature of the working fluid being analyzed. For industrial lubricants, such as paper machine oils, the length of the electrodes shown in FIG. 1 typically will be in the range of between about 0.5 cm to about 20 cm, the diameter of the outer electrode between about 0.5 cm to about 4 cm and the gap between the inner and outer electrode between about 0.1 to 10 mm. Other geometries for the electrodes may be employed, such as flat parallel plates, flat interdigitated electrodes etched on an inert substrate and the like. Placing the electrodes in a working fluid contained in a mechanical system permits on-line, real time, analysis of the fluid, i.e., the condition of the fluid can be measured continuously while employed in the mechanical system without the need to remove a sample of the fluid from the system for analysis. An AC signal is applied to one electrode at a plurality of frequencies, typically at more than two frequencies, preferably at more than three frequencies, for example from 3 to 1000 frequencies and preferably from 4 to 20 in the range of from 1 Hz to 1 MHz. The applied signal produces an electrical output at the other electrode, which is measured. A device for applying the signal and measuring the output is a frequency response analyzer (FRA). Such frequency response analyzers are commercially available devices and are used to acquire frequency dependent impedance data. Another fluid impedance monitor is shown schematically in FIG. 1 where 1 and 2 represent concentric electrodes immersed in an oil 4. A digital function generator 5 generates a predetermined discrete sequence of signals and a digital-to-analog converter 6 converts the sequence to an analog sinusoidal voltage of small amplitude, Vn, and frequency, ω, and applies the voltage to the outer electrode 2. The applied signal produces an electrical charge on the inner electrode 1. A charge amplifier 7 converts the charge into a sinusoidal voltage, Vout, at the same frequency, ω. The time-based waveforms of both input and output voltages are converted by an analog-to-digital converter 8 and the resulting data is acquired and processed by data processor 9. In the data processor 9, a digital frequency response analyzer is used to obtain the complex transfer function of the output voltage with respect to the input voltage, i.e., the ratio of the complex amplitude of the sinusoidal output voltage to that of the sinusoidal input voltage. This complex transfer function is equal to the ratio of the feedback impedance of the charge amplifier 7 to the impedance of the working fluid to be analyzed. Dividing the transfer function by the known amplifier feedback impedance, the admittance of the working fluid is obtained. The reciprocal of the admittance is equal to the impedance of the working fluid. The process of data acquisition and processing can be repeated over all operating frequencies over a period of time. Time Dependent Impedance Spectra In a simple acquisition and processing mode, the process of data acquisition and processing can be made over a period of time at a fixed frequency. Impedance plotted as a function of time at a fixed frequency provides a time dependent impedance spectrum. Impedance plotted as a function of time over a multiplicity of frequencies provides a series of time dependent impedance spectra. One can also plot admittance instead of impedance and obtain a series of time dependent admittance spectra. Time dependent impedance spectra are preferred. Frequency Dependent Impedance Spectra In a preferred embodiment the AC signal is applied at a plurality of frequencies, for example from 3 to 1000 frequencies and preferably from 4 to 20 in the range of from 1 Hz to 1 MHz and frequency dependent impedance or admittance data are obtained. These frequency dependent impedance or admittance data are used to determine one or more of the resistance, the capacitance, the frequency at which the phase angle between the voltage and current is 45° (Omega max), the time constant of the working fluid and dielectric constant. This can be achieved, for example, by plotting the frequency dependent impedance data in the form of a Nyquist plot where, in rectangular coordinates, imaginary impedance (Z″=im(Z)=[Z] Sin(Θ)) is plotted against real impedance (Z′=re(Z)=[Z] Cos(Θ)) or, in polar coordinates, |Z|=[(Z′)2+(Z″)2]1/2 is plotted against Θ, the phase difference between voltage and current. Examples of Nyquist plots are shown in FIG. 2 for a paper machine lubricant. In FIG. 2, the Y axis is the negative of the imaginary part of impedance, Z″ and the x axis is the real part of impedance, Z′. Preferably the Nyquist plot of frequency dependent impedance data is further analyzed by fitting the data to a least-squares best fit curve. Such a curve can be fit using many standard data analysis packages. The resistance of the oil/electrode system can then be calculated by determining the diameter of the curve along the x axis. The frequency at which Θ reaches 45 degrees is known as Omega max. The reciprocal of Omega max is the time constant, RC. The capacitance may then be determined using relations, Omega max=1/RC. Alternately, by choosing a frequency that is sufficiently high, for example by choosing a frequency greater than about 10,000 Hz, the capacitance can be approximated from a single impedance measurement. Dielectric constant is defined as the ratio of capacitance of the electrode in the fluid to the capacitance of the electrode in a vacuum. By measuring the capacitance and knowing the capacitance of the electrode in a vacuum the dielectric constant of the fluid is calculated. The frequency dependent impedance data can be measured for three, preferably for four or more values of Θ spanning a range of at least 45 degrees and a partial Nyquist curve is constructed from that data. This portion of the curve can then be analyzed with a standard least squares fitting program by assuming that the Nyquist plot follows an elliptical curve. The entire Nyquist curve can then be constructed by extrapolating to Θ values of zero and 180 degrees. At the same time values for capacitance, resistance and Omega max can also be determined. Deconvolution of Time Dependent Impedance Spectra The time dependent impedance or admittance spectrum of a working fluid is generally complicated or convoluted. Such a complicated or convoluted spectrum is of limited utility. In one embodiment of the invention is a method to deconvolute a time dependent impedance spectrum of a lubricant oil. A time dependent impedance spectrum of the lubricant oil is obtained over a time range and at a plurality of time intervals wherein the time dependent impedance spectrum comprises at least one peak. Preferably simultaneously, is measured at least one lubricant property, preferably at least two lubricant properties, for the lubricant oil over the same time range and plurality of time intervals to provide at least one or preferably a plurality of time dependent lubricant property spectra. The next step involves comparing the obtained time dependent impedance spectrum with the measured at least one or a plurality of time dependent lubricant property spectra. Where the peaks of each coincide in time, to the peaks on the time dependent impedance spectrum is assigned the lubricant property of the measured coinciding time dependent lubricant properties, resulting in a deconvoluted time dependent impedance spectrum. A series of lubricant properties include but are not limited to properties such as additive degradation, base oil oxidation, temperature change, water and other polar species contamination, and viscosity changes of the lubricant oil. It is preferred to determine the time dependent impedance spectrum and the time dependent lubricant properties on-line. By on-line is meant during operation of the machinery comprising the working fluid. The time dependent impedance spectrum can be determined at one frequency or a multitude of frequencies. It is preferred to determine the time dependent impedance spectrum at a multitude of frequencies, in which case, a multitude of time dependent impedance spectra are generated. This multitude of time dependent impedance spectra recorded over a period of time wherein each spectrum corresponds to time dependent data at a single characteristic frequency of determination we call a series of time dependent impedance spectra. Typically, a time dependent impedance spectrum will exhibit at least one peak. The peak can be a positive peak or a negative peak. A time dependent impedence spectrum can exhibit a plurality of peaks. The method of deconvoluting a time dependent impedance spectrum involves the assigning to at least one peak of the time dependent impedance spectrum a character corresponding to the measured lubricant property that has peaks in the spectrum that coincide in time. For the preferred on-line determination of a series of time dependent lubricant properties including but not limited to properties such as additive degradation, base oil oxidation, temperature change, water and other polar species contamination, and viscosity changes of the lubricant oil a series of corresponding lubricant property sensors can be placed into the lubricating oil. Each on-line sensor can measure its characteristic lubricant property over a period of time corresponding to the time the impedance measurements are made. It is preferred to measure the time dependent lubricant properties over the same time range and at the same time interval the time dependent impedence spectra are measured. It is preferred to measure the impedance spectrum and lubricant properties for the period of operation and lifetime of the machinery or system comprising the working fluid. Typically this can range from about 1 day to about 10 years. It is preferred to measure the impedance spectrum and lubricant properties at a time interval in the range of about 12 hours to about lyear. The preferred time period of measurement is dependent on the time range of measurement. One of ordinary skill in the art can determine the desired time period of measurement. Using Tables-1 and 2 the invention is further illustrated. Measurement of one lubricant property (for example, P1) as a function of time generates a corresponding lubricant property time dependent spectrum (for example TDSP1). This spectrum will exhibit a positive or negative peak at a specific time (for example, at t1) when the property, P1 undergoes a change. Similarly, measurement of another lubricant property P2 as a function of time in the same time period of measurement will produce a P2 time dependent spectrum TDSP2 exhibiting a peak at t2. Thus for each of lubricant properties P1 to Pn, n number of corresponding time dependent spectra TDSP1 to TDSPn are generated. Each TDSPn can exhibit a characteristic peak at tn. A property-time table (Table-1) can be generated as shown below: TABLE 1 Property Spectra Time at which peak is observed P1 TDSP1 t1 P2 TDSP2 t2 Pn TDSPn tn A time dependent impedance spectrum is generated for same time range and at the same time interval the lubricant properties are measured. This time dependent impedance spectrum can have a number of peaks I1 to In at times t1 to tn. A time dependent impedance spectrum can also be represented in tabular from (Table-2) shown below. TABLE 2 Time at which impedance peak is observed Peak number t1 I1 t2 I2 t3 I3 tn In The property-time table (Table-1) is compared to the time dependent impedance spectrum table (Table-2) and to each impedance peak I1 to In is assigned lubricant property P1 to Pn. It is not essential to assign each and every peak on the impedance spectrum to a lubricant property. Preferably, at least one peak on the impedance spectrum is assigned a lubricant property. More preferably at least two peaks on the impedance spectrum are assigned to lubricant properties. The assignment is made based on the time t1 to tn of occurrence of the peaks by a one-one correspondence method. A non-limiting example of a time dependent dielectric constant spectrum is shown in FIG. 3, curve-A. In this example, peak I1 occurring at time t1 will be assigned property P1, that is, the first peak occurring at about 270 hours is assigned to water in the lube oil. The time dependent impedance spectrum with at least one peak (I) assigned to a particular lubricant property (P) is the deconvoluted time dependent impedance spectrum. The deconvolution method described above for a single frequency can be applied to each time dependent spectrum of a series of time dependent impedance spectra determined at a multiplicity of frequencies to obtain a series of deconvoluted time dependent impedance spectra. As described earlier, frequency dependent impedance can be used to determine one or more of the resistance (R), the capacitance (C), the dielectric constant, the frequency at which the phase angle between the voltage and current is 45°, the time constant (or Omega max) of the working fluid. The disclosed method of deconvolution of time dependent impedance spectrum can be applied for the deconvolution of time dependent resistance (R), capacitance (C), dielectric constant and the time constant (or Omega max) spectra as derived from a frequency dependent impedance spectrum. It is preferred to obtain the impedance and lubricant property time dependent spectra on-line and in real time of operation of the machinery under examination. Preferably, the AC elecro-impedance and lubricant property measurements made on low conductivity industrial oils are made at a temperature above about 50° C. and more preferably above about 65° C. and up to about 150° C. It is preferred to determine impedance spectrum in the frequencies range between 1 and 30,000 Hz. More preferably 1 to 10,000 Hz. In another embodiment of the invention is a method to use a time dependent spectrum as an indicator of the performance condition of a lubricant oil. A time dependent spectrum of the lubricant oil is obtained over a time range and at a plurality of time intervals, wherein said spectrum comprises at least one peak and said spectrum is selected from the group consisting of impedance spectrum, admittance spectrum, resistance spectrum, capacitance spectrum, phase angle spectrum and dielectric spectrum. At least one lubricant property is measured over said time range and at said plurality of time intervals to provide at least one time dependent lubricant property spectrum. Preferably, the measurement of lubricant property is conducted simultaneously with the measurement of the time dependent spectrum of the lubricant oil. The next step involves comparing the obtained time dependent spectrum with the measured time dependent lubricant property spectra. In the case where the peaks of each coincide in time, the comparison includes assigning to the peaks on the time dependent spectrum the lubricant property of the measured coinciding time dependent lubricant properties whereby the time dependent spectrum is used as an indicator of the measured lubricant property. In the case where the peaks of each do not coincide in time, the time dependent spectrum is used as an indicator of reduced performance condition of the lubricant oil. The lubricant oil can be analyzed using a single deconvoluted time dependent impedance spectrum determined at one frequency. Preferably, the lubricant fluid is analyzed using a series of deconvoluted time dependent impedance spectra determined at a multitude of frequencies. One reason for the complicated or convoluted nature of impedance spectra is that impedance is a very sensitive measurement and responds to many factors resulting in a time dependent spectra with a multitude of peaks. Factors such as water contamination, temperature change, oil oxidation, and viscosity reduction can be determined simultaneously with the impedence measurements and the peaks corresponding to these can be assigned as disclosed earlier. For example, a reduction in viscosity by a certain factor or ingress of water beyond a threshold amount as indicated from the deconvoluted time dependent impedance, resistance, capacitance, dielectric constant or phase angle spectrum is an indicator of reduced lubricant performance. Occurrence of peaks other than those assigned is an indicator that the performance condition of the lubricant oil is altered. The method of the instant invention allows the operator of a machinery comprising a working fluid such as a lubricant oil to determine the performance condition of the working fluid. When the performance condition of the working fluid is reduced the operator is signaled or alerted to such change. A long-standing need for such an alert is fulfilled by the method of the instant invention. In another embodiment of the invention is a method to determine viscosity ratio of a lubricating oil from frequency dependent impedance data. Viscosity ratio (VR) of a lubricating fluid can be expressed as VR=Vt/V0 where Vt is the viscosity of said fluid at any time t after which it is subject to lubrication function and V0 is the initial viscosity at time, t=0 . A method to determine viscosity ratio of a lubricating oil from frequency dependent impedance spectra comprises first measuring frequency dependent impedance data for the lubricating oil and then using the said data to determine one or more of the resistance, the capacitance, the frequency at which the phase angle between the voltage and current is 45° (Omega max), the time constant of the lubricating fluid and dielectric constant using the Nyquist plot. It is preferred to determine the resistance (R) of the lubricating fluid. It is preferred to determine the resistance (R) of the lubricating fluid at time t=0 and any time, t during operation of the machinery comprising the lubricating fluid. The resistance (Ro) at time t=0 is the initial resistance of the lubricating fluid. The resistance at any time t is denoted Rt. The resistance ratio is calculated and is equal to Rt/Ro. In the second step, the optical density or absorbance (A) of the lubricating oil at time, t is determined at a wavelength in the range of 500 to 1050 nm, preferably in the range of 750 to 975 nm, and more preferable at about 800 nm. The absorbance and resistance measurements are made at the same temperature. From the measured absorbance (A) at time, t and the resistance ratio (RR) Rt/Ro the viscosity ratio (VR) is determined using the expression: VR={RR+C1+C2(A−C3)}/C4 where C1 C2 and C3 are numbers whose absolute values range from 0 to 10,000. C4 is a number whose absolute value ranges from 0.005 to 10,000. The absolute values of C1, C2, C3 and C4 will depend on the composition of the working fluid. For example, the values of C1, C2, C3 and C4 are 5.481, 0.559, 0.221 and 6.439 respectively for the paper machine oil of Example-2 used to illustrate the instant invention. The values of C1, C2, C3 and C4 can be determined from a regression plot of calculated viscosity ratio versus measured viscosity ratio as illustrated in FIG. 4 and Example-2. The viscosity ratio (VR) determined using the frequency dependent impedance and absorbance measurements can be used to determine the quality of the lubricant oil. The greater the deviation from unity the poorer the quality of the oil. It is preferred to measure the impedance and absorbance data for the lubricating oil on-line and in real time. It is also preferred to make the impedance and absorbance measurements at the same temperature. The calculated VR is then an on-line viscosity ratio of the lubricant oil. Thus, the lubricant quality can be monitored continuously over the period of working of the machinery comprising the lubricant oil. The method to determine viscosity ratio of a lubricating oil from frequency dependent impedance data can also be used to determine other properties of the lubricating oil such as and not limited to additive concentration, ingress of foreign particulate concentration and water concentration. The invention as disclosed in the instant application is applicable to any working fluid that can be subject to impedance measurements and not limited to a lubricant oil. A lubricant oil is one illustrative example of such a working fluid. EXAMPLES Example 1 Dielectric constant, relative humidity, and temperature measurements were made for an industrial oil X over a 500 hour time period in a lubricant rig test. Results of this test are shown in FIG. 3 and are represented as curves A, B and C corresponding to dielectric constant, water and temperature respectively. Curve-A shows two distinct changes or peaks. It is to be noted the peaks are negative peaks on the dielectric spectrum (Curve-A). The first change in the dielectric signal corresponding to the first peak is contamination, in this case water. The next observable change is the second peak. This peak can be assigned to a temperature decrease. By combining the two lubricant property sensors in this experimental set these distinctions are made and result in deconvolution of the impedance spectrum. Further, interpretation of the deconvoluted impedance spectrum provides information that the lubricant oil has gradually reduced performance over the course of 500 hour time period. Example 2 Six different paper machine oils were oxidized by heating them in an oven at 140 C for 12 days with copper and steel rods, which served as catalysts to increase oxidation rate. Periodically samples were withdrawn from the containers and analyzed by measuring their optical absorbance (A) at 800 nm through a 1 cm thick liquid sample. Samples were also analyzed using AC impedance spectroscopy at multiple frequencies and resistance, R, was calculated. Kinematic viscosity was measured for each sample by the ASTM D 455 method. FIG. 4 shows a plot of measured viscosity ratio (viscosity of sample/viscosity of fresh oil ie., oil before commencement of oxidation) determined by the ASTM D 455 method versus the viscosity ratio calculated using the expression: VR={RR+C1+C2(A−C3)}/C4 where C1, C2, C3 and C4 are 5.481, 0.559, 0.221 and 6.439 respectively. The observed linearity of the plot is an illustration of one embodiment of the instant invention ie., method to determine viscosity ratio of a lubricating oil from frequency dependent impedance data | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention is broadly concerned with deconvolution of impedance spectra of a working fluid. The invention is also concerned with using deconvoluted impedance spectra as an indicator of the performance condition of a working fluid. | <SOH> SUMMARY OF THE INVENTION <EOH>Working fluids, such as lubricating oils and hydraulic fluids, are important components of a wide variety of mechanical systems in which they provide one or more functions such as lubricating moving parts, transferring force or energy on the mechanical system, protecting parts against wear or even a combination of these. These fluids typically consist of hydrocarbon base oil formulated with numerous performance additives selected to enhance one or more performance characteristics of the fluid. With use over time these fluids may become contaminated with substances with which they come into contact, by the ingress of foreign substances in the mechanical system, by oxidation of the base oil and chemical decomposition of the additives used in the formulated fluids. The net result is a decrease in the performance characteristics of the fluid with the concomitant negative impact on the mechanical system using the fluid. Therefore, in many industrial environments regular fluid analysis by common laboratory methods is a standard modus operandi. This necessitates obtaining a sample of the fluid and transporting it, typically off-site, for analysis. This procedure normally takes at least three full days before the requisite analysis is completed and a report can be obtained. Such a time lag is highly undesirable. Many proposed methods for the on-line evaluation of the quality of lubricants are based on electrical measurements, such as the dielectric constant or impedance of the fluid, with the measurements being taken at one fixed frequency or a multiplicity of frequencies. Since the best frequency for optimum sensitivity often depends on the properties or operational conditions of the working fluid it is preferred to make impedance measurements at a multiplicity of frequencies. One subset of impedance measurements is dielectric measurements. Data obtained from time dependent impedance measurements are generally extremely complicated or convoluted. Additive degradation, base oil oxidation, temperature change, water and other polar species contamination, and viscosity changes of the lubricant oil can impact impedance properties of a lubricant oil. A method to deconvolute time dependent impedance spectra is needed so that the deconvoluted time dependent impedance spectra can provide information about the lubricant. One object of the present invention is to provide a method for deconvolution of time dependent impedance spectra. Another object of the present invention is to provide a method to utilize deconvoluted time dependent impedance spectra as an indicator of the performance condition of a fluid. Yet another object of the invention is a method to determine the viscosity ratio of a fluid by measuring frequency dependent impedance spectra. These and other objects will become apparent from the description, which follows. In one embodiment of the invention is a method to deconvolute a complex time dependent impedance spectrum of a lubricant oil comprising: obtaining a time dependent impedance spectrum of the lubricant oil over a time range and at a plurality of time intervals wherein the time dependent impedance spectrum comprises at least one peak, measuring at least one lubricant property over said time range and said plurality of time intervals to provide at least one time dependent lubricant property spectrum wherein the time dependent lubricant property spectrum comprises at least one peak, comparing said obtained time dependent impedance spectrum with said measured time dependent lubricant property spectra, where the peaks of each coincide in time, assigning to the peaks on the time dependent impedance spectrum the lubricant property of said measured coinciding time dependent lubricant properties, resulting in a deconvoluted time dependent impedance spectrum. In another embodiment of the invention is a method to use a time dependent spectrum as an indicator of the performance condition of a lubricant oil comprising: obtaining a time dependent spectrum of the lubricant oil over a time range and at a plurality of time intervals, wherein said spectrum comprises at least one peak and said spectrum is selected from the group consisting of impedance spectrum, admittance spectrum, resistance spectrum, capacitance spectrum, phase angle spectrum and dielectric spectrum, measuring at least one lubricant property over said time range and at said plurality of time intervals to provide at least one time dependent lubricant property spectrum having at least one peak, comparing said obtained time dependent spectrum with said measured time dependent lubricant property spectrum, where the peaks of each coincide in time, assigning to the peaks on the time dependent spectrum the lubricant property of said measured coinciding time dependent lubricant properties whereby the time dependent spectrum is used an indicator of the measured lubricant property, and where the peaks of each do not coincide in time the time dependent spectrum is used as an indicator of reduced performance condition of the lubricant oil. In yet another embodiment of the invention is a method to determine the viscosity ratio (VR) of a lubricating oil in a machinery comprising: measuring frequency dependent impedance data for the lubricating oil over a range of frequencies and over a time range, determining the resistance (R) of the lubricating fluid using a Nyquist plot, at starting time t=0 and a particular time, t within said time range, and denoting the resistance at time t=0 as R o and the resistance at time t as R t , calculating a resistance ratio RR=R t /R o , measuring the absorbance (A) of the lubricating oil at said time, t at a wavelength in the range of 500 to 1050 nm, calculating the value of {RR+C 1 +C 2 (A−C 3 )}/C 4 where C 1 , C 2 and C 3 are numbers whose absolute values range from 0 to 10,000, and C 4 is a number whose absolute values range from 0.005 to 10,000, said determined value being the viscosity ratio (VR) of the lubricating oil. | 20040706 | 20050405 | 20050217 | 88201.0 | 0 | NGUYEN, TRUNG Q | METHOD FOR DECONVOLUTION OF IMPEDANCE SPECTRA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,885,345 | ACCEPTED | Automatic threshold selection method for improving the detection of a wireless signal | System and method for improving the detection performance of a wirelessly transmitted signal. A preferred embodiment comprises specifying a desired response for missed channel detection and false alarm probabilities for a plurality of signal qualities and determining if a channel detection threshold is based on missed channel detection or false alarm probabilities for the plurality of signal qualities. A signal quality estimate of a channel can be inferred from a signal quality measurement of a second channel, wherein the channel and the second channel are sourced by a single transmitter. The channel detection threshold can be adjusted based upon the previously determined required response and the signal quality estimate of the channel. | 1. A method for detecting a value transmitted on a channel received by a receiver, the method comprising: inferring a signal-to-noise ratio (SNR) for the channel; selecting a channel detection threshold based upon the inferred SNR; and applying a detection rule with the selected channel detection threshold. 2. The method of claim 1, wherein the inferred SNR for the channel is inferred from an estimate of a SNR from a second channel. 3. The method of claim 2, wherein the channel is signaled by a network, wherein the second channel is also signaled by the network, and a power offset between the channel and the second channel is known. 4. The method of claim 1, wherein the inferred SNR for the channel can be directly estimated. 5. The method of claim 1, wherein the selecting is further based upon a determination of if the channel detection threshold is based upon a missed channel detection or a false alarm probability. 6. The method of claim 5, wherein the determination of if the channel detection threshold is based upon a missed channel detection or a false alarm probability can be determined for different channel SNRs. 7. The method of claim 5, wherein the determination of if the channel detection threshold is based upon a missed channel detection or a false alarm probability can be determined before it is needed and can be stored in a memory. 8. The method of claim 1, wherein the applying comprises: receiving symbols transmitted on the channel; and determining the value of the symbols based upon the threshold. 9. The method of claim 8, wherein multipath may exist in the channel, wherein the receiver has a rake receiver with a plurality of fingers, wherein each finger is assigned to receive data from a unique path, wherein the rake receiver uses maximal ratio combining (MRC) to combine data from the fingers, and wherein the determining comprises: for data from each path, estimating received channel bit energy for the path from an estimate of bit energy from a second channel; computing a channel estimate for the path; computing a noise variance estimate for the path; and applying the detection rule. 10. The method of claim 9, wherein the detection rule can be expressed as: L lo g ( x _ ) = ∑ i = 1 L - 4 σ ^ i 2 Re { α ^ i E ⅇ - j θ ^ i x i } H 1 ≥ < H 0 log ( γ ) wherein: Llog(x) is the log-likelihood ratio of the channel, {circumflex over (α)}i2ÊbCPICH is the estimate of bit energy from the second channel, ΔPICH is the channel to the second channel offset (in dB), {circumflex over (α)}i2ÊP={circumflex over (α)}i2ÊC*10ΔPICH/10 is the relationship between the estimated received channel bit energy and the bit energy of the second channel, {circumflex over (θ)}i is the channel estimates for each path, {circumflex over (σ)}i2 is the noise variance for each path, and log(γ) is the threshold. 11. The method of claim 9, wherein the threshold is further determined based upon the quality of the channel estimation. 12. The method of claim 8, wherein multipath may exist in the channel, wherein the receiver has a rake receiver with a plurality of fingers, wherein each finger is assigned to receive data from a unique path, wherein the rake receiver uses pilot weighted combining (PWC) to combine data from the fingers, and wherein the determining comprises: for data from each path, estimating received channel bit energy for the path from an estimate of bit energy from a second channel; computing a channel estimate for the path; and applying the detection rule. 13. The method of claim 12, wherein the detection rule can be expressed as: L lo g ( x _ ) = ∑ i = 1 L - Re { α ^ i E P ⅇ - j θ ^ i x i } H 1 ≥ < H 0 log ( γ ~ ) wherein: Llog(x) is the log-likelihood ratio of the channel, {circumflex over (α)}i2ÊbCPICH is the estimate of bit energy from the second channel, ΔPICH is the channel to the second channel offset (in dB), {circumflex over (α)}i2ÊP=*{circumflex over (α)}i2ÊC*10 ΔPICH/10 is the relationship between the estimated received channel bit energy and the bit energy of the second channel, {circumflex over (θ)}i is the channel estimates for each path, {circumflex over (σ)}i2 is the noise variance for each path, and log(γ) is the threshold. 14. The method of claim 12, wherein the threshold is further determined based upon the quality of the channel estimation. 15. A method for customizing the detection of a value transmitted on a channel received by a receiver, the method comprising: specifying a desired response for a missed channel detection probability and a false alarm probability for a plurality of signal qualities; (1) determining if channel detection threshold is based on missed channel detection or false alarm probability for the plurality of signal qualities; setting a threshold based upon the determining at each of the plurality of signal qualities; inferring a signal-to-noise ratio (SNR) for the channel; selecting a channel detection threshold based upon the inferred SNR and results from the determining; and applying a detection rule with the selected channel detection threshold. 16. The method of claim 15, wherein the inferred SNR for the channel can be inferred from an estimate of a SNR from a second channel or it can be directly estimated. 17. The method of claim 16, wherein the channel and the second channel are transmitted by the same source. 18. The method of claim 17, wherein the method is used in a Universal Mobile Telephony System (UMTS) compliant communications system, and wherein the channel is a paging indicator channel (PICH) and the second channel is a broadcast common pilot channel (CPICH). 19. The method of claim 15, wherein the specifying comprises specifying a desired missed channel detection probability and a false alarm probability for each of the plurality of signal qualities. 20. The method of claim 19, wherein SNR is a metric of signal quality, and each of the plurality of signal qualities spans a SNR range. 21. The method of claim 15, wherein multiple desired responses can be specified, each for a different operating condition, and wherein the determining can be applied to each desired response and the results of the determining for each desired response stored for subsequent use. 22. The method of claim 21, wherein the second determining can be based upon the inferred channel SNR and the results for a desired response selected based upon operating conditions. 23. The method of claim 15, wherein the selecting is also based upon results from the setting. 24. The method of claim 15 further comprising: receiving symbols transmitted on the channel; and (2) determining the value of the symbols based upon the threshold. 25. The method of claim 24, wherein multipath may exist in the channel, wherein the receiver has a rake receiver with a plurality of fingers, wherein each finger is assigned to receive data from a unique path, wherein the rake receiver uses maximal ratio combining (MRC) to combine data from the fingers, and wherein the second determining comprises: for data from each path, estimating received channel bit energy for the path from an estimate of bit energy from a second channel; computing a channel estimate for the path; computing a noise variance estimate for the path; and applying the detection rule. 26. The method of claim 25, wherein the detection rule can be expressed as: L lo g ( x _ ) = ∑ i = 1 L - 4 σ ^ i 2 Re { α ^ i E ⅇ - j θ ^ i x i } H 1 ≥ < H 0 log ( γ ) wherein: Llog(x) is the log-likelihood ratio of the channel, {circumflex over (α)}i2ÊCPICH is the estimate of bit energy from the second channel, ΔPICH is the channel to the second channel offset (in dB), {circumflex over (α)}i2ÊP={circumflex over (α)}i2ÊC*10ΔPICH/10 is the relationship between the estimated received channel bit energy and the bit energy of the second channel, {circumflex over (θ)}i is the channel estimates for each path, {circumflex over (σ)}i2 is the noise variance for each path, and log(γ) is the threshold. 27. The method of claim 24, wherein multipath may exist in the channel, wherein the receiver has a rake receiver with a plurality of fingers, wherein each finger is assigned to receive data from a unique path, wherein the rake receiver uses pilot weighted combining (PWC) to combine data from the fingers, and wherein the second determining comprises: wherein for data from each path, estimating received channel bit energy for the path from an estimate of bit energy from a second channel; computing a channel estimate for the path; and applying the detection rule. 28. The method of claim 27, wherein the detection rule can be expressed as: L lo g ( x _ ) = ∑ i = 1 L - Re { α ^ i E P ⅇ - j θ ^ i x i } H 1 ≥ < H 0 log ( γ ~ ) wherein: Llog(x) is the log-likelihood ratio of the channel, {circumflex over (α)}i2ÊbCPICH is the estimate of bit energy from the second channel, ΔPICH is the channel to the second channel offset (in dB), {circumflex over (α)}i2ÊP={circumflex over (α)}i2ÊC*10ΔPICH/10 is the relationship between the estimated received channel bit energy and the bit energy of the second channel, {circumflex over (θ)}i is the channel estimates for each path, {circumflex over (σ)}i2 is the noise variance for each path, and log(γ) is the threshold. 29. The method of claim 15, wherein the specifying, determining, and setting can be performed at an earlier time and results stored for later use. | This application claims the benefit of U.S. Provisional Application No. 60/545,420, filed Feb. 17, 2004, entitled “Automatic Threshold Selection Method for Improving the Detection of a Wireless Signal” which application is hereby incorporated herein by reference. TECHNICAL FIELD The present invention relates generally to a method for digital communications, and more particularly to a method for improving the detection performance of a wirelessly transmitted signal. BACKGROUND In many wireless communications systems, such as Universal Mobile Telephony Systems (UMTS) and other third generation (3GPP) wireless communications systems, a communications device is often put into a sleep mode in order to decrease power consumption and increase battery life. The communications device can then wake up at fixed intervals to check if it is the recipient of an incoming page. In UMTS, this is referred to as the DRX mode, or discontinuous reception mode. To further reduce the amount of time that the communications device needs to be active when it is operating in the DRX mode, the communications device can decode an indicator channel which can contain a Boolean value specifying if it is the recipient of an incoming page. If there is no incoming page, then the communications device can go back to sleep. If there is an incoming page, then the communications device can decode the paging channel to receive the details of the incoming page (or simply, receive the incoming message). The quality of the wireless channel can have a significant impact on the accuracy of the decoding of the channel. For a low quality channel, perhaps due to the communications device being far removed from the base station to which it is communicating or the communications device being operated within a tunnel or large building, the signal quality of the channel (commonly referred to as signal-to-noise ratio (SNR)) can be low. When the SNR of the indicator channel is low, then the probability of the communications device erroneously decoding the indicator channel can be high. Conversely, when the SNR of the indicator channel is high, then the probability of erroneously decoding the indicator channel can be low. If the indicator channel is erroneously decoded, the communications device may erroneously decode the indicator channel one of two ways: a false alarm or a missed page. With a false alarm, the communications device would decode the indicator channel as indicating that there is an incoming page when there isn't one, thereby unnecessarily increasing power consumption and reducing battery life. While with the missed page, the communications device would decode the indicator channel as not indicating that there is an incoming page when there is an incoming page resulting in a missed call (since the presence of a page is usually followed by a call). A commonly used method for detecting the state of the indicator channel is referred to as the maximum likelihood (ML) method. The ML method uses a zero threshold and assumes that the a priori probabilities of being paged and not being paged are the same and that the costs of erroneously decoding the indicator channel (the false alarm and missed page) are the same. Another commonly used method for detecting the state of the indicator channel is referred to as the Neyman Pearson (NP) method. The NP method permits a threshold to be set with unequal false alarm and missed detection probabilities. The NP method is typically used to set a performance metric, such as a constant missed detection (or false alarm) probability across the range of SNRs, and then the other performance metric, i.e., false alarm (or missed detection) probability can be automatically determined. Essentially, there is one degree of freedom since there is only one threshold to set with two performance metrics. Therefore, setting the threshold based upon one performance metric would result in the automatic determination of the other performance metric. One disadvantage of the prior art is that the ML method permits only the assignment of equal costs for erroneously decoding the state of the indicator channel as either a missed page or false alarm. Furthermore, it also assumes that the probability of being paged and not being paged are equal. These assumptions are incorrect in real-world applications and their use can result in poor performance. A second disadvantage of the prior art is that the NP approach does not adapt the threshold by taking into consideration the fact that the sensitivity of the overall performance metrics (battery life and missed call rate) to PICH detection may change over an entire range of SNRs (or equivalently, the location of the communications device in relation to a cell site). Rather, the NP approach attempts to keep either the missed PICH rate or the false alarm probability constant over the entire range of SNRs. SUMMARY OF THE INVENTION These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by preferred embodiments of the present invention which provides for a system and method for improving the detection performance of a wireless transmitted signal. In accordance with a preferred embodiment of the present invention, a method for detecting a value transmitted on a channel received by a receiver, the method comprising inferring a signal-to-noise ratio (SNR) for the channel and selecting a channel detection threshold based upon the inferred SNR. The method further comprises applying a detection rule with the selected channel detection threshold. In accordance with another preferred embodiment of the present invention, a method for customizing the detection of a value transmitted on a channel received by a receiver, the method comprising specifying a desired response for a missed channel detection probability and a false alarm probability for a plurality of signal qualities. For each of the plurality of signal qualities specified, the method includes determining if a channel detection threshold is to be based upon the missed channel detection or false alarm probability and setting a threshold based upon the determined channel detection threshold. Furthermore, a signal-to-noise ratio (SNR) is inferred for the channel and a channel detection threshold is selected using the inferred SNR and results from the determining. Finally, a detection rule can be applied with the selected channel detection threshold. An advantage of a preferred embodiment of the present invention is that it is possible to design a customized response for either the missed detection or false alarm probability across the range of SNRs (or equivalently, across different locations in the coverage area of a communications cell). A customized response may be desirable since the indicator channel detection performance can be one component of overall missed call performance and the sensitivity of the overall paging channel detection performance to the indicator channel detection may not be uniform across the range of SNRs. A further advantage of a preferred embodiment of the present invention is that it can permit the capping of the false alarm probability to a value where its influence on the overall power consumption (and battery life) of the communications device is negligible. With the false alarm probability capped, it can be possible to reduce the missed indicator channel detection probability. This can allow for the customization of the missed indicator channel detection probability in certain SNR ranges and the false alarm probability in other SNR ranges. Yet another advantage of a preferred embodiment of the present invention is that it is possible to correctly calculate the noise variance that is to be used in threshold setting. The noise variance calculation in the present invention can correctly account for noisy channel estimates used in PICH demodulation. This accurate calculation of the noise variance can also help in the detection based upon the NP method. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: FIG. 1 is a diagram of an operating area coverage map of a wireless communications system; FIG. 2 is a diagram of an algorithm that can be used by a communications device for detecting incoming pages while operating in a DRX mode; FIG. 3 is a data plot of a communications device's awake time versus the probability of false alarm in a static channel environment, according to a preferred embodiment of the present invention; FIG. 4 is a data plot of contributions to a missed page as a function of signal geometry, according to a preferred embodiment of the present invention; FIGS. 5a and 5b are diagrams of algorithms that can be used for offline and online automatic adjustment of the PICH detection threshold and PICH symbol decoding, according to a preferred embodiment of the present invention; FIGS. 6a and 6b are diagrams of an algorithm used for PICH detection when a rake receiver in the communications device uses maximal ratio combining or pilot weighted combining, according to a preferred embodiment of the present invention; FIGS. 7a and 7b are data plots illustrating the probability of missed calls and average awake times for different PICH detection techniques in a static channel environment, according to a preferred embodiment of the present invention; FIGS. 8a and 8b are data plots illustrating the probability of missed calls and average awake times for different PICH detection techniques in a fading channel environment, according to a preferred embodiment of the present invention; and FIG. 9 is a diagram of an algorithm for use in decoding a received PICH symbol, according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS The making and using of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. The present invention will be described with respect to preferred embodiments in a specific context, namely a UMTS wireless communications system using a paging indicator channel. An introduction to the technical specifications for a UMTS wireless communications system may be found in a document entitled “3rd Generation Partnership Project; Technical Specifications Group Services and System Aspects General UMTS Architecture (Release 4),” published March 2004. The invention may also be applied, however, to other wireless communications systems that make use of an indicator channel to help in the decoding of another channel, such as CDMA2000, CDMA ONE, GSM, and so forth. Furthermore, the invention has application in the detection of wirelessly transmitted signals. With reference now to FIG. 1, there is shown a diagram illustrating an operating area coverage map of a wireless communications system 100. The wireless communications system 100, which can be a UMTS wireless communications system, comprises a base station (BTS) 105. The BTS 105 can have an operating area that can be represented by a dashed circle 110. Note that the dashed circle 110 may be an idealized view of the operating area of the BTS 105 and that an actual operating area may be irregularly shaped, depending upon the presence (or lack) of physical barriers to signals transmitted by the BTS 105. The wireless communications system 100 may also include a pair of communications devices, a first communications device 115 and a second communications device 120. The communications devices may also be referred to as user equipment (UE) or mobile. Note that for illustrative purposes, the wireless communications system 100 is shown with two communications devices and that the wireless communications system 100 may actually have more (or fewer) communications devices. The first communications device 115 can be separated from the BTS 105 by a distance ‘D1,’ shown as a first dashed line 117, while the second communications device 120 may be separated from the BTS 105 by a distance ‘D2,’ shown as a second dashed line 122. As shown in FIG. 1, the distance ‘D1’ is greater than the distance ‘D2.’ Therefore, the signal from the BTS 105 to the first communications device 115 should be weaker than the signal from the BTS 105 to the second communications device 120. In a UMTS wireless communications network, a communications device can be placed in a sleep mode wherein it can periodically wakeup to determine if there is an incoming page. If there are no incoming pages, the communication device can return to sleep. This mode of operation is referred to as discontinuous reception mode (DRX). When in DRX mode, the communications device can considerably reduce its power consumption as compared to a fully active communications device. To further help reduce the power consumption, the communications device does not have to attempt to decode a paging channel (PCH) for a message that may not be present. Rather, the communications device decodes a paging indicator channel (PICH) for a single Boolean value that indicates if there is an incoming page, which, if positive, would then cause the communications device to decode the PCH to receive the message. Since the decoding of a single Boolean value is typically much shorter than the decoding of a message and the probability of an incoming page being present each time the communications device wakes up is small, the decoding of the PICH for the single Boolean value can reduce the power consumption of the communications device. Please refer to U.S. Pat. No. 6,650,912, entitled “Selecting Paging Channel Mode” for a detailed discussion of the use of a paging indicator channel to reduce power consumption in a wireless communications device. Additional discussion of the use of paging indicator channels to reduce power consumption and increase standby time can be found in a technical paper by S. Sarkar, B. Butler, and E. Tiedemann, entitled “Phone Standby Time in cdma2000: The Quick Paging Channel in Soft Handoff,” IEEE Transactions on Vehicular Technology, volume 50, pp 1240-1249, published September 2001. With reference now to FIG. 2, there is shown a flow diagram illustrating an algorithm 200 that can be used by a communications device for detecting incoming pages while operating in DRX mode. The algorithm 200 illustrates a sequence of operations that can be executed by a processing element, controller, general purpose processing unit, special purpose processing unit, custom designed integrated circuit, or so on in a communications device to detect and receive incoming pages while the communications device is operating in the DRX mode. As discussed previously, the communications device may operate in the DRX mode when it is not in active use, in order to reduce power consumption. When in the DRX mode, the communications device reads an indicator channel (also referred to as a paging indicator channel) to determine if it should read the paging channel to receive an incoming message. When in the DRX mode, the majority of the time, the communications device is in a sleep mode (or a suspend mode). Then, at periodic intervals, the communications device wakes up to read the indicator channel (PICH) (block 205). In a UMTS wireless communications channel, the PICH can carry a flag (or Boolean value) that can be set or un-set depending on whether or not the communications device is being paged. The duration of the interval that the communications device spends sleeping can be dependent upon factors such as the length of the DRX cycle as specified by UTRAN, the length of the wake up time, and so forth. After waking up, the communications device can detect and decode the PICH (block 210). Since the PICH basically conveys a single value to the communications device, the detecting and decoding of the PICH by the communications device should occur in short order. The communications device can then determine if it is the recipient of a page (block 215) based upon the value of the flag. If the communications device determines that it is the recipient of a page, then the communications device should decode the paging channel (PCH) in order to receive the message (block 220). After completing its reception of the page, the communications device can act upon the received message (block 222). For example, the communications device can proceed to a traffic channel (as specified in the received message) and begin two-way (or one-way) communications, such as a voice call with another user or a data call with a data source/sink. If the communications device determines that it is not the recipient of a page, then the communications device can place itself back to sleep (block 225). PICH detection directly affects the two important metrics of battery life and missed call rate and therefore it is imperative that the PICH be decoded correctly with high probability. The PICH can be decoded incorrectly in one of two ways: a false alarm or a missed page. A false alarm occurs when the PICH is decoded as indicating that the communications device is the recipient of a page when it actually is not. A false alarm can result in an increase in power consumption since the communications device must attempt to decode the PCH for a page that is not there. A missed page occurs when the PICH is decoded as indicating that the communications device is not the recipient of a page when it actually is. A missed page can result in a missed call since the communications device does not know that it is being paged. With reference now to FIG. 3, there is shown a data plot illustrating a communication device's awake time (an average duration for which the communications device is active per DRX cycle) versus probability of PICH false alarm in a static channel environment, according to a preferred embodiment of the present invention. The amount of time that the communication device spends awake when operating in the DRX mode can be expressed as: Awake—time=TPICH+[Pfa(1−Ppage)+(1−Pm)Ppage]TPCH Awake—time≈TPICH+Pfa*TPCH, wherein TPICH is the amount of time that the communications device spends to decode the PICH, TPCH is the amount of time that the communications device spends to decode the PCH, Pfa is the probability of a false alarm, Ppage is the probability of being paged, and Pm is the probability of a missed page. The approximation for Awake_time arises from the fact that the probability of being paged in a single DRX cycle can be very small. A curve 300 displays the amount of time that the communications device spends awake for different values of Tfa. The curve 300 shows that when the probability of a false alarm drops from 20% (indicated in FIG. 3 as highlight 305) to 1% (indicated in FIG. 3 as highlight 310), the awake time of the communications device drops by approximately a factor of two (2). However, reducing the probability of a false alarm below 1%, results in a negligible reduction in the awake time. Therefore, it is clear that reducing the probability of false alarm below a certain point (approximately 1% to 5%) may not be beneficial. With reference now to FIG. 4, there is shown a data plot illustrating contributions to a missed page as a function of signal geometry, according to a preferred embodiment of the present invention. Note that signal geometry is a quantity that is directly proportional to the signal-to-noise ratio (SNR) of the signal. In some cases, SNR can be used in place of signal geometry and still convey a similar meaning. When operating in the DRX mode, the missed call rate can be dependent upon several contributors and can be expressed as: Pmc=1−(1−Pfail—racq)(1−Pfail—DPE)(1−PTFC)(1−PPCH)(1−PPICH) wherein Pfail—reacq is the probability of error due to real-time clock (RTC) calibration error, Pfail—DPE is the probability of a missed paging indicator due to a searcher error, PTFC is the probability of a missed paging indicator due to a transport format combination (TFC) decoding error, PPCH is the decoder error probability on the PCH, and Pm is the probability of a missed PICH. FIG. 4 displays the contributions to Pmc for each of the contributors for a range of SNR values. A first curve 405 displays Pmc for the range of signal geometries. A second curve 410 displays the contribution to Pmc of PPCH, while a third curve 415 displays the contribution of PPICH. A fourth curve 420 displays the contribution of PTFC. A fifth curve 425 displays the contributions of Pfail—reacq. Note that Pfail—DPE is much lower and hence not shown in FIG. 4. A single point 430 displays a required missed call probability at a single signal geometry (0 dB). The single point 430 displays a performance requirement as specified by the UMTS technical standards. The contributors to the missed call rate Pmc can have different signal geometry ranges wherein they are dominant. For example, for a signal geometry range of less than −3 dB, the dominant contributor to Pmc is PPCH, the decoded error probability on the PCH. For a signal geometry range of greater than −3 dB, the dominant contributor to Pmc is PPICH. As discussed previously, the setting of a threshold that is used for detecting the value of the Boolean value carried on the PICH presents a tradeoff between missed detection (resulting in a missed call) or false alarm (directly affecting battery life and standby time). The changing of the threshold to decrease one (either missed detection or false alarm probability) comes at the expense of increasing the other. For example, using a given detection method, if the missed detection probability is lowered through the setting of a threshold, then the false alarm probability will correspondingly increase. Since the probability of a missed call can be dominated by different factors depending upon the quality of the signal (for example, signal geometry or SNR), it can be possible to trade missed detection and battery life. In situations with low signal quality (low signal geometry or SNR) or equivalently, operation at the edge of operating areas, the missed call rate is dominated by high error probability of the PCH itself. Therefore, the overall paging channel detection performance may not be sensitive to PICH detection. In this instance, setting a missed PICH detection probability of 1% or lower could be wasteful. Setting the missed PICH detection probability at a higher percentage (10-50%, for example) can result in similar performance with a better battery life. In situations with intermediate signal quality (medium signal geometry or SNR), a missed call probability may require that the missed PICH detection probability be very small (for example, 0.1 to 0.5%). Furthermore, the false alarm probability may be capped at 5 to 10% for higher signal quality situations (high signal geometry or SNR), since it makes little difference to the battery life if it is set at a lower level (as shown in FIG. 3), and then the missed PICH detection probability can be reduced in these regions. The dominance of different contributors to the overall missed call rate at different signal quality ranges can permit variations in the setting of the missed PICH detection probability (missed page probability) and the false alarm probability based upon a sensitivity analysis. This may lead to the development of an algorithm that can automatically adjust the PICH detection threshold based upon the quality of the received signal. The ability to set the detection threshold to trade off the missed PICH detection probability and the false alarm probability at different signal geometries can enable the trading off between missed calls and higher standby time in the different signal geometries. Doing so requires the addition of minimal complexity to the communications device since parameters necessary for use are either already estimated at the communications device (such as the common pilot signal energy and noise variance) or are signaled by the network (such as the common pilot to PICH power offset ratio). Furthermore, some of the estimations and computations can be performed prior to their use, such as during an initial power-on operation or even during communications device manufacture or programming. This is commonly referred to as offline computation, while the computations and estimations performed during use are commonly referred to as online computations. With reference now to FIGS. 5a and 5b, there are shown flow diagrams illustrating algorithms that can be used for offline (algorithm 500, FIG. 5a) and online (algorithm 550, FIG. 5b) computations to automatically adjust the PICH detection threshold, referred to as automatic threshold selection concept (ATC), according to a preferred embodiment of the present invention. According to a preferred embodiment of the present invention, the algorithm 500 may be used to specify and precompute some of the parameters and values used to automatically adjust the PICH detection threshold prior to when a communications device enters the DRX operation mode, while the algorithm 550 can be executed on the communications device while the communications device is operating in the DRX operation mode. The algorithm 500 can be executed during initial power-on operations or after a reset/reboot operation of the communications device. Alternatively, the algorithm 500 can be executed prior to the manufacture of the communications device or at a service provider prior to the distribution of the communications device to customers. In either case, the parameters and values computed and specified by the algorithm 500 can be stored in the communications device (such as in a memory or a register bank) for subsequent use. A first operation in the algorithm 500 involves the specifying of a desired response for the missed PICH detection probability (PPICH) and the false alarm probability (Pfa) as a function of the signal quality (signal geometry or SNR) (block 505). For example, it can be possible to specify a different missed PICH detection probability and a false alarm probability for low, medium, and high signal geometry or SNR ranges (such as described previously). Such a desired response could take into account the relative sensitivity of the performance metrics to PICH detection. After specifying a desired response as a function of signal quality (block 505), a second operation in the algorithm 500 determines if the PICH detection threshold will be based upon the missed PICH detection probability or the false alarm probability over the signal geometry or SNR range of interest (block 510). Furthermore, the second operation sets the threshold to be used in the detection rule (also block 510). After the second operation completes, the results of the execution of the algorithm 500 can be stored in the communications device for later use. According to a preferred embodiment of the present invention, it may be possible to specify a different response (block 505) and a different set of PICH detection thresholds can be determined (block 510) for different missed PICH detection and false alarm probability responses. Each set of PICH detection thresholds can be stored in the communications device. Then, if the performance resulting from a set of PICH detection thresholds is not as expected, then the communications device can switch to a different set of PICH detection thresholds to possibly help improve performance. The algorithm 500 can be used to produce parameters for the various signal geometry or SNR ranges that can be stored in the communications device for subsequent use. According to a preferred embodiment of the present invention, the parameters can be stored in a look-up table. A preferred embodiment of the look-up table can have three columns of data. A first column can represent the various signal geometry or SNR ranges for which a threshold is specified, a second column can indicate whether the missed PICH detection or false alarm probability is used, and a third column of data can provide the detection threshold itself. The look-up table can have as many rows of data as the number of signal geometry or SNR ranges for which missed PICH detection and false alarm probabilities are specified in block 505. Note that if multiple missed PICH detection and false alarm probability responses are specified, then multiple look-up tables can be stored in the communications device. Alternatively, a single large look-up table can be used to stored the thresholds for the multiple missed PICH detection and false alarm probability responses. The use of a look-up table and its design is considered well understood by those of ordinary skill in the art of the present invention and will not be discussed herein. The algorithm 550, which was described previously, can execute on a communications device while the communications device is operating in the DRX operating mode. According to a preferred embodiment of the present invention, the algorithm 550 is executed each DRX cycle by the communications device. The communications device can begin by estimating the SNR of the PICH by estimating the SNR of another channel (block 555). Alternatively, the SNR of the PICH can be directly estimated. The estimation of the SNR is performed using a channel that is also being signaled by the network, just as the PICH. For a UMTS wireless communications system, the channel used maybe the common pilot channel (CPICH) because the power offset between the PICH and the CPICH is signaled to the communications device by the network. However, other channels that are also signaled by the network can be used in the estimation of the SNR if the power offset between the channels is known. The estimated SNR of the other channel can then be used as the inferred SNR of the PICH. After inferring the SNR of the PICH, the communications device can select a channel detection threshold using both the inferred SNR and previously calculated information regarding if the PICH detection threshold should be set based on missed PICH detection probability or false alarm probability (block 560). The information regarding if the PICH detection threshold should be set based on missed PICH detection probability or false alarm probability was previously calculated using algorithm 500 (FIG. 5a) and stored in memory. Finally, the communications device apply the detection rule (block 565). The application of the detection rule can differ based upon the way in which data from the fingers of the rake receiver is combined in the communications device. The application of the detection rule for two different methods of combining finger data is presented below. Note that it may be possible for the quality of PICH to change during operation. The communications device can then adjust the threshold based upon the PICH SNR. In a UMTS wireless communications system, the PICH can indicate a single bit of information to the communications device, wherein the single bit of information is modulated using binary-phase shift keying (BPSK) and can take on one of two values: +1 (indicating that the communications device is not being paged) and −1 (indicating that the communications device is being paged). Assuming an L path communications channel, the received signal after de-spreading by a rake receiver can be written in vector form and expressed as: {tilde over (x)}={square root}{square root over (EP/2)}A(1+j)αejθ+{tilde over (w)}, where it is assumed that the transmitted PICH symbol is {square root}{square root over (EP/2)}A(1+j), A can have the value of either +1 or −1 wherein a +1 can indicate that the communications device is not being paged and a −1 can indicate that the communications device is being paged, the complex channel gain is given by αejθ=[α1ejθ1α2ejθ2 . . . αL ejθL] and the additive noise vector is {tilde over (w)}. It is assumed here that {tilde over (w)} is a multivariate Gaussian random vector with zero mean and uncorrelated elements. The variances of real and imaginary parts of {tilde over (w)}i are each σi2/2. (Note that this noise variance includes any inter-path interference and therefore, in general, is path dependent). Multiplying {tilde over (x)} by (1−j)/{square root}{square root over (2)} yields the new vector, expressible as: x={square root}{square root over (EP)}Aαejθ+w. Note that the statistics of the noise vectors w and {tilde over (w)} are identical. The corresponding received CPICH (i.e. pilot) symbols are expressible as: x={square root}{square root over (EC)}Aαejθ+n, where the noise vector n is a multi-variate Gaussian random vector with zero mean and uncorrelated elements. The variances of real and imaginary parts of ni are σi2/2. The vectors n and w are mutually uncorrelated as well. Note that the assumption that the per path noise variance for the PICH symbol and the CPICH symbol are the same is not essential for the ensuing analysis and only simplifies the presentation. The threshold setting should be a function of the noise variances in both the CPICH and PICH because the CPICH is used for channel estimation and subsequent coherent demodulation of the PICH. The analysis shown here, correctly accounts for noisy channel estimates used in PICH demodulation. Note that the analysis here and resultant methodology will also make detection using the Neyman-Pearson method more accurate in the presence of a practical channel estimation. It is also known that even though the channel estimates are represented as pilot symbols, they may also be obtained by averaging or filtering the pilot symbols. One commonly used method for combining finger data is maximal ratio combining (MRC). In MRC, the data from each finger in the rake receiver can be weighed by a quantity that is proportional to the SNR of the path being demodulated by that finger, so that data from paths with greater SNR has greater significance in the decision statistic. The log-likelihood ratio (LLR) for the paging indicator bit (conditioned on the channel gain) is expressible as: L log ( x _ ) = log P ( x _ | A = - 1 ) P ( x _ | A = 1 ) = ∑ i = 1 L log P ( x i | A = - 1 ) P ( x i | A = 1 ) , where the second equality is a result of assuming independence among the paths. It follows then, that: L log ( x _ ) = ∑ i = 1 L - 4 E σ i 2 [ Re { α i ⅇ - j θ i x i } ] . Now, the hypothesis test is to compare Llog(x) to a threshold as follows: L log ( x _ ) = ∑ i = 1 L - 4 σ i 2 Re { α i E ⅇ - j θ i x i } ⋛ H 0 H 1 log ( γ ) . In practice channel estimates from the CPICH would be used for demodulation and therefore, the hypothesis test is: L log ( x _ ) = ∑ i = 1 L - 4 σ ^ i 2 Re { α ^ i E ⅇ - j θ ^ i x i } ⋛ H 0 H 1 log ( γ ) . With reference now to FIG. 6a, there is shown a flow diagram illustrating an algorithm 600 used in PICH detection when a rake receiver in the communications device uses maximal ratio combining, according to a preferred embodiment of the present invention. According to a preferred embodiment of the present invention, the algorithm 600 can be an implementation of block 565 (FIG. 5b), wherein the detection rule is applied using information generated by algorithm 500, which may be stored in a look-up table. An initial operation (block 605) in the algorithm 600 can be to estimate the received PICH bit energy from the estimate of the CPICH bit energy ({circumflex over (α)}i2ÊbCPICH) for each path in the communications channel and the CPICH to PICH offset (in db), referred to as ΔPICH, which is signaled by the network. With these estimated values, {circumflex over (α)}i2ÊP={circumflex over (α)}i2ÊC*10ΔPICH/10 is known. It may be then possible to obtain channel estimates for each path from the CPICH, {circumflex over (θ)}i (block 610). Alternatively, the first and second operations (blocks 605 and 610) can be combined into a single operation by computing a complex channel estimate from the CPICH and then scaling it by the square root of the PICH offset. Note that with a zero threshold (such as when a ML detector is used), the PICH offset would then not have a role in the decision rule. After estimating the received PICH bit energy (block 605) and the channel estimates for each path (block 610), the third step can be to obtain an estimate of the noise variance for each path, {circumflex over (σ)}i2 (block 615). All of the data needed to perform the hypothesis test is now known, and the PICH detection rule can be applied (block 620). The threshold, log(γ), is set to attain a certain false alarm or missed PICH detection probability as specified in block 510 of algorithm 500 (FIG. 5a). Shown below is an example of threshold setting for a fixed missed PICH detection probability. It should be noted that threshold setting based upon a false alarm probability is very similar and therefore is not shown. P m ( γ ) = P { L log ( x _ ) < log ( γ ) | H 1 } = P { ∑ i = 1 L 4 σ ^ i 2 Re [ α ^ i E ⅇ - j θ ^ i x i ] > - log ( γ ) } The threshold is obtained as: log γ = { arg { P m ( γ ) = P m , target ( SNR ) } threshold based on MP arg { P m ( γ ) = P fa , target ( SNR ) } threshold based on FA An accurate method for setting the threshold would be to determine the missed PICH detection probability expression that considers the statistics of the estimates âi and {circumflex over (σ)}i2, in addition to the noise present in xi. For MRC, this is often intractable, because of the statistics of the noise variance estimate. However, as a sub-optimum approach for MRC, the method presented treats the estimates as deterministic parameters and computes the missed PICH detection probability purely based upon the noise present in xi. With this approach, the decision statistic becomes Gaussian and the missed PICH detection probability can be computed as: P m ( γ ) = Q ( ∑ i = 1 L 4 α ^ i 2 E σ ^ i 2 - log ( γ ) ∑ i = 1 L 8 α ^ i 2 E σ ^ i 2 ) wherein Q is can be expressed as: Q ( x ) = ∫ x ∞ 1 2 π exp ( - u 2 2 ) ⅆ u . In order to set the threshold for MRC, the PICH SNR is inferred from the estimates of the CPICH SNR and the above equation is inverted. In practice, a look-up table may be used to invert the Q(.) equation above. With reference now to FIG. 6b, there is shown an algorithm 650 used in PICH detection when a rake receiver in the communications device uses pilot weighted combining, according to a preferred embodiment of the present invention. As an alternative to MRC, a simpler approach called pilot weighted combining (PWC) is often used. PWC combines each path using the channel estimate of each path. According to a preferred embodiment of the present invention, the algorithm 650 can be an implementation of block 565 (FIG. 5b), wherein the threshold is selected from the results generated by algorithm 500, which may be stored in a look-up table. Note that the algorithm 650 also includes an application of the selected threshold. For PWC, the PICH hypothesis can be expressed as: L log ( x _ ) = ∑ i = 1 L - Re { α ^ i E P ⅇ - j θ ^ i x i } ⋛ H 0 H 1 log ( γ ~ ) . Note that the algorithm 650 for PWC can be similar to the algorithm 600 for MRC with the exception that the algorithm 650 does not need to estimate the noise variance for each path (block 615 (FIG. 6a)). Unlike in the case of MRC, in PWC, the threshold determination that precisely accounts for noise in both the signal and the channel estimate is possible. As an example, consider a case wherein the channel does not change significantly over a slot duration (for UMTS, 0.667 ms) and that the channel estimates can be obtained by simply averaging the symbols of a pilot received in a slot. For this case, the channel estimate of the i-th path can be expressed as: α ^ i ⅇ j θ ^ i = 1 N E C ∑ j = 1 N y ij = 1 N E C ∑ j = 1 N ( a i ⅇ j θ i E C + n ij ) , where j is the symbol index and there are N CPICH symbols in a slot. The j-th received pilot symbol on the i-th path can be referred to as yij. A one-slot straight average filter of the kind shown above is commonly used for channel estimation on the downlink in CDMA systems. Equivalently, {circumflex over (α)}iej{tilde over (θ)}i=aiejθi{square root}{square root over (EC)}+{overscore (n)}i, where {overscore (n)}i is complex Gaussian with a variance of real and imaginary parts equal to σi2/(2N). The noise variance has been reduced by a factor of N due to the one-slot averaging. With this model, each term in the decision statistic, Re{{circumflex over (α)}ie−j{circumflex over (θ)}iXi}, is no longer strictly Gaussian due to the “product of noise” terms (noise in the channel multiplying noise in the signal). However, at typical operating SNRs, the “product of noise” terms are generally small compared to other noise terms and maybe ignored. The resulting Gaussian approximation can be quite accurate. Setting the Gaussian approximation and matching the mean and variance of each term in the decision statistic, the missed PICH detection probability can be expressed as: P m ( γ ~ ) = Q ( log γ ~ + μ σ ~ ) , μ = ∑ i = 1 L α i 2 E C E P where σ ~ 2 = 1 2 ∑ i = 1 L ( α i 2 σ i 2 ( E C + E P / N ) + σ i 4 / N ) . The threshold log(γ) can now be obtained by inverting the expression for the missed PICH detection probability. If the threshold is to be set based upon false alarm probability, a similar approach can be followed. Note that the threshold setting for PWC is similar to that for MRC, as discussed above. With reference now to FIGS. 7a and 7b, there are shown data plots illustrating probability of missed calls and average awake times for different PICH detection techniques in a static channel environment, according to a preferred embodiment of the present invention. The data plots shown in FIGS. 7a and 7b compare the performance of ATC with that of ML and NP techniques using link level simulations. In the NP technique, a target of 5% PICH false alarm probability for all SNRs was used. For ATC, a missed PICH detect probability of 40% was used until SNR reached −2 dB. After SNR exceeded −2 dB, the false alarm probability was set at 5%. One motivation for such a custom response can be that at low SNRs, the missed call rate is little influenced by the missed PICH detection, therefore, the false alarm probability was improved. Then, as the SNR increased, the false alarm rate was fixed at 5% while the missed PICH detection probability was decreased. Note that the custom response used in the simulations is used merely for illustration. In practice, a smoother custom response may be preferred. FIG. 7a illustrates the simulation results for missed call probability for a channel with additive white Gaussian noise (AWGN). A first curve 705 shows the performance of the ML technique, a second curve 710 shows the performance of the NP technique, while a third curve 715 shows the performance using ATC. A point 720 displays the required performance of a UMTS wireless communications system as specified in the technical standards. FIG. 7b illustrates the simulation results for average awake time for the same AWGN channel, wherein a fourth curve 755 shows the performance for the ML technique, a fifth curve 760 shows the performance for the NP technique, and a sixth curve 765 shows the performance using ATC. In FIG. 7a, it is shown that the NP technique (the first curve 705) offers better performance than ATC (the third curve 715) for missed call performance. However, when viewed in conjunction with the awake times shown in FIG. 7b, it is clear that ATC provides a better average awake time (the sixth curve 765 as opposed to the fourth curve 755). In general, ATC provides both good missed call and awake time performance. Note that the results shown in FIGS. 7a and 7b are for a single specified set of missed PICH detection and false alarm probabilities as a function of signal geometry and that for the single specified set, NP performed better than ATC in missed call performance but ATC offered a lower average awake time. It is important to note that it is possible to specify the missed PICH detection and false alarm probabilities as a function of SNR so that ATC will perform identical to NP and/or ML. Therefore, the performance of ATC shown in FIGS. 7a and 7b is the result of the desire to emphasize average awake time (thereby increasing battery life) over missed call performance. Furthermore, NP also benefits from the correct accounting of the channel estimation error as described earlier in this disclosure. The techniques for setting the detection threshold for ATC can also be applied to setting the detection threshold for NP, and as a result, the performance of NP can be improved. Finally, it should be noted that both ATC and NP perform better than the traditional ML approach. This is the result of the setting of the detection threshold and the correct accounting of the channel estimation quality. With reference now to FIGS. 8a and 8b, there are shown data plots illustrating average awake times and probability of missed PICH for different PICH detection techniques in a fading channel environment, according to a preferred embodiment of the present invention. The data plots shown in FIGS. 8a and 8b compare the performance of ATC with that of ML and NP techniques using link level simulations. The same false alarm and missed PICH detection probabilities used in the simulations to obtain the results shown in FIGS. 7a and 7b are used to obtain the results shown in FIGS. 8a and 8b. FIG. 8a illustrates the simulation results for average awake times for a three path equal energy Rayleigh fading channel, wherein a first curve 805 shows the performance for the ML technique, a second curve 810 shows the performance for the NP technique, and a third curve 815 shows the performance using ATC. FIG. 8b illustrates the probability of missed PICH detection for a three path equal energy Rayleigh fading channel, wherein a fourth curve 855 shows the performance for the ML technique, a fifth curve 860 shows the performance of the NP technique, and a sixth curve 865 shows the performance using ATC. In FIG. 8a, it is shown that when the channel conditions are poor, ATC (the third curve 815) offers a lower average awake time than either the ML (the first curve 805) or the NP (the second curve 810) techniques. However, when the channel conditions are good, ATC offers a longer average awake time. However, when the results of FIG. 8b are examined, it is clear that ATC is trading off longer average awake times to achieve a lower missed PICH detection probability (the sixth curve 865). With reference now to FIG. 9, there is shown a flow diagram illustrating an algorithm 900 for use in decoding a received PICH symbol, according to a preferred embodiment of the present invention. The algorithm 900 shows the decoding of a received PICH symbol based upon a single specified value for either the missed PICH detection or false alarm probability. The algorithm 900 can therefore be an implementation of the algorithms 500 and 550 (FIGS. 5a and 5b) for a single SNR range when ATC is used or for an entire range of possible signal SNRs when NP is used. The algorithm 900 can be executed on a controller, a processing element, a general purpose processor, a dedicated processor, a custom designed integrated circuit, or so forth, of a communications device that is operating in DRX operating mode. Portions of the algorithm 900 can be executed prior to the communications device entering DRX operating mode. Before the communications device enters the DRX operating mode, such as during an initial power-up configuration or during manufacture, a decision can be made on setting an acceptable value of either Pm or Pfa (block 905). Note that the value chosen for Pm or Pfa may need to be adherent to the technical standards specifying the operation of the communications device. After setting a value for Pm or Pfa, then T is calculated (block 910), wherein T=Q−1(Pm) or T=Q−1(Pfa), wherein T is the value of the inverse complementary error function for a specific value, such as Pm or Pfa. Note that the calculation of T may need to be performed one time and the result can be stored in a memory (or register) for subsequent use. It may also be possible to store the values of T for different values of Pm or Pfa so that the calculation may not need to take place. The values of T can simply be written to a look-up table during the manufacture (or programming) of the communications device. With T calculated for the set value of Pm or Pfa, the communications device can enter the DRX operating mode, wherein at each DRX cycle, the controller of the communications device can measure the SIR (signal-to-interference ratio) of the CPICH (block 915). The SIR of the CPICH can be used to determine the threshold to be used. The SIR of the CPICH can be measured in two different ways. A first way to measure the CPICH SIR can be to assign the fingers of the rake receiver and measure CPICH Es and Nt over a certain number of slots. Based upon the measured Es and Nt of the CPICH, the CPICH SIR can be computed as: SIR_CPICH=Es/Nt in dB. Note that it is preferred that Es and Nt be measured over a period of three (3) slots. Alternatively, searcher hardware (a part of the communications device used to perform correlations) can be used to calculate the CPICH Ec/Io in dB. Using Ec/Io, the CPICH SIR can be computed as: SIR_CPICH = CPICH Ec Io - 10 log 10 ( 1 + I or I oc ) + log 10 ( SF CPICH ) wherein Ec/Io is a ratio of average power in the second channel to total signal power, Ior is the power spectral density of a band limited white noise source, Ioc is the received power spectral density of a signal measured at a receiver, SFCPICH is the spreading factor of CPICH. The alternate method for calculating CPICH SIR can be accurate at low geometric factors since the second term (the term containing Ior/Ioc) is not present at the communications device. From the CPICH SIR, the PICH SIR can be calculated (block 920). The PICH SIR can be calculated from the CPICH SIR (calculated in block 815) using the expression: SIR_PICH = SIR_CPICH + PICH PowerOffset + 10 log 10 ( SF PICH · N SF CPICH ) , wherein SIR_PICH is the SIR of the PICH, SIR_CPICH is the SIR of the CPICH, PICHPowerOffset is the power offset of the PICH, SFPICH and SFCPICH are the spreading factors of the PICH and the CPICH, and N is the number of bits carrying indicators in the PICH divided by the number of unique paging indicators and is equal to 288/Np (for a UMTS wireless communications system). After calculating the PICH SIR from the CPICH SIR, the controller can again measure Nt for a number of slots (block 925), preferably three (3), and demodulate symbols being transmitted on the PICH (block 930). The demodulated PICH symbols can then be normalized by the measured Nt. The PICH detection threshold can then be adjusted (block 935), using the PICH SIR calculated previously. Depending upon the probability being optimized (Pm or Pfa), the PICH detection threshold can be adjusted using the techniques discussed previously. Then, using the PICH detection threshold, from block 935, the value of the normalized PICH symbols, y, can be determined (block 940). Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | <SOH> BACKGROUND <EOH>In many wireless communications systems, such as Universal Mobile Telephony Systems (UMTS) and other third generation (3GPP) wireless communications systems, a communications device is often put into a sleep mode in order to decrease power consumption and increase battery life. The communications device can then wake up at fixed intervals to check if it is the recipient of an incoming page. In UMTS, this is referred to as the DRX mode, or discontinuous reception mode. To further reduce the amount of time that the communications device needs to be active when it is operating in the DRX mode, the communications device can decode an indicator channel which can contain a Boolean value specifying if it is the recipient of an incoming page. If there is no incoming page, then the communications device can go back to sleep. If there is an incoming page, then the communications device can decode the paging channel to receive the details of the incoming page (or simply, receive the incoming message). The quality of the wireless channel can have a significant impact on the accuracy of the decoding of the channel. For a low quality channel, perhaps due to the communications device being far removed from the base station to which it is communicating or the communications device being operated within a tunnel or large building, the signal quality of the channel (commonly referred to as signal-to-noise ratio (SNR)) can be low. When the SNR of the indicator channel is low, then the probability of the communications device erroneously decoding the indicator channel can be high. Conversely, when the SNR of the indicator channel is high, then the probability of erroneously decoding the indicator channel can be low. If the indicator channel is erroneously decoded, the communications device may erroneously decode the indicator channel one of two ways: a false alarm or a missed page. With a false alarm, the communications device would decode the indicator channel as indicating that there is an incoming page when there isn't one, thereby unnecessarily increasing power consumption and reducing battery life. While with the missed page, the communications device would decode the indicator channel as not indicating that there is an incoming page when there is an incoming page resulting in a missed call (since the presence of a page is usually followed by a call). A commonly used method for detecting the state of the indicator channel is referred to as the maximum likelihood (ML) method. The ML method uses a zero threshold and assumes that the a priori probabilities of being paged and not being paged are the same and that the costs of erroneously decoding the indicator channel (the false alarm and missed page) are the same. Another commonly used method for detecting the state of the indicator channel is referred to as the Neyman Pearson (NP) method. The NP method permits a threshold to be set with unequal false alarm and missed detection probabilities. The NP method is typically used to set a performance metric, such as a constant missed detection (or false alarm) probability across the range of SNRs, and then the other performance metric, i.e., false alarm (or missed detection) probability can be automatically determined. Essentially, there is one degree of freedom since there is only one threshold to set with two performance metrics. Therefore, setting the threshold based upon one performance metric would result in the automatic determination of the other performance metric. One disadvantage of the prior art is that the ML method permits only the assignment of equal costs for erroneously decoding the state of the indicator channel as either a missed page or false alarm. Furthermore, it also assumes that the probability of being paged and not being paged are equal. These assumptions are incorrect in real-world applications and their use can result in poor performance. A second disadvantage of the prior art is that the NP approach does not adapt the threshold by taking into consideration the fact that the sensitivity of the overall performance metrics (battery life and missed call rate) to PICH detection may change over an entire range of SNRs (or equivalently, the location of the communications device in relation to a cell site). Rather, the NP approach attempts to keep either the missed PICH rate or the false alarm probability constant over the entire range of SNRs. | <SOH> SUMMARY OF THE INVENTION <EOH>These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by preferred embodiments of the present invention which provides for a system and method for improving the detection performance of a wireless transmitted signal. In accordance with a preferred embodiment of the present invention, a method for detecting a value transmitted on a channel received by a receiver, the method comprising inferring a signal-to-noise ratio (SNR) for the channel and selecting a channel detection threshold based upon the inferred SNR. The method further comprises applying a detection rule with the selected channel detection threshold. In accordance with another preferred embodiment of the present invention, a method for customizing the detection of a value transmitted on a channel received by a receiver, the method comprising specifying a desired response for a missed channel detection probability and a false alarm probability for a plurality of signal qualities. For each of the plurality of signal qualities specified, the method includes determining if a channel detection threshold is to be based upon the missed channel detection or false alarm probability and setting a threshold based upon the determined channel detection threshold. Furthermore, a signal-to-noise ratio (SNR) is inferred for the channel and a channel detection threshold is selected using the inferred SNR and results from the determining. Finally, a detection rule can be applied with the selected channel detection threshold. An advantage of a preferred embodiment of the present invention is that it is possible to design a customized response for either the missed detection or false alarm probability across the range of SNRs (or equivalently, across different locations in the coverage area of a communications cell). A customized response may be desirable since the indicator channel detection performance can be one component of overall missed call performance and the sensitivity of the overall paging channel detection performance to the indicator channel detection may not be uniform across the range of SNRs. A further advantage of a preferred embodiment of the present invention is that it can permit the capping of the false alarm probability to a value where its influence on the overall power consumption (and battery life) of the communications device is negligible. With the false alarm probability capped, it can be possible to reduce the missed indicator channel detection probability. This can allow for the customization of the missed indicator channel detection probability in certain SNR ranges and the false alarm probability in other SNR ranges. Yet another advantage of a preferred embodiment of the present invention is that it is possible to correctly calculate the noise variance that is to be used in threshold setting. The noise variance calculation in the present invention can correctly account for noisy channel estimates used in PICH demodulation. This accurate calculation of the noise variance can also help in the detection based upon the NP method. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. | 20040706 | 20080610 | 20050818 | 67619.0 | 0 | TRAN, KHANH C | AUTOMATIC THRESHOLD SELECTION METHOD FOR IMPROVING THE DETECTION OF A WIRELESS SIGNAL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,885,450 | ACCEPTED | Composite door lock plunger | An approved plunger assembly is provided for a door handle. The plunger assembly includes a metallic plunger and a plastic link, which are connected so as to slide together between extended and retracted positions. The plastic link minimizes friction between the plunger assembly and the housing of the door handle, and minimizes wear between the link and the pivot plate which moves the plunger assembly from the extended position to the retracted position. The metallic plunger provides increased wear-resistance from contact with the striker plate or frame which surrounds the door in which the door handle is mounted. | 1. An improved door handle having a housing with a plunger tunnel, a paddle pivotally mounted on the housing, and a pivot plate pivotally mounted on the housing for actuation by the paddle, the improvement comprising: a metal plunger slidably mounted in the plunger tunnel; and a plastic link having a first end connected to the plunger and a second end engaged by the pivot plate; whereby actuation of the paddle pivots the pivot plate to slide the link and retract the plunger within the tunnel. 2. The improved door handle of claim 1 wherein the plunger has a recess and the link has a finger received in the recess so as to connect the plunger and link together. 3. The improved door handle of claim 1 wherein the link has a shoulder for engagement by the pivot plate. 4. The improved door handle of claim 3 wherein the shoulder is formed by a recess in the link. 5. The improved door handle of claim 1 wherein the plunger is made from zinc. 6. An improved plunger assembly for a door handle, comprising: a metal plunger, and a plastic link, the plunger and link being connected so as to move together between extended and retracted positions. 7. The improved plunger assembly of claim 6 wherein the plunger has a recess and the link has a finger received in the recess so as to connect the plunger and link together. 8. The improved plunger assembly of claim 6 wherein the link has a shoulder for engagement by an actuation plate of the door handle. 9. The improved plunger assembly of claim 8 wherein the shoulder is formed by a recess in the link. 10. The improved plunger assembly of claim 6 wherein the plunger is zinc. 11. A plunger assembly for a door handle, comprising: a plunger made from wear-resistant material; a link made from material having a low coefficient of friction; the plunger and link being connected so as to move together between extended and retracted positions. 12. The plunger assembly of claim 11 wherein the coefficient of friction of the link is less than the coefficient of friction of the plunger. 13. The plunger assembly of claim 11 wherein the wear-resistance of the plunger is greater than the wear-resistance of the link. 14. The plunger assembly of claim 11 wherein the hardness of the plunger is greater than the hardness of the link. | BACKGROUND OF THE INVENTION Door handles, such as those used on vehicles, including ingress and egress doors as well as compartment doors, such as on an RV, typically include a housing with a paddle pivotally mounted on the housing, and a pivot plate pivotally mounted on the rear of the housing for actuation by the paddle. A plunger is mounted on the housing for movement between a normally extended position to hold the door closed and a retracted position to allow opening of the door. Actuation of the handle causes the pivot plate to slide the plunger from the extended position to the retracted position. The frame surrounding the door handle typically includes a striker plate or surface which is struck by a beveled edge on the plunger as the door moves from the opened position to the closed position, with the plunger extending into a recess or behind the striker plate to retain the door in the closed position. Prior art plungers have a one-piece construction, and have been made of both metal and plastic. A metal plunger has increased friction, which increases the release efforts required to open the door. Also, a metal plunger has increased wear with the pivot plate, which is normally made of steel, so that the plunger has a reduced life expectancy. In comparison, a plastic plunger has a reduced coefficient of friction, as compared to a metal plunger, so as to minimize the release efforts required to open the door, but has poor wear caused by repeated engagement with the striker plate so as to reduce the life of the plastic plunger. Accordingly, the primary objective of the present invention is the provision of an improved plunger assembly for a door handle which has reduced friction and increased life. Another objective of the present invention is the provision of a composite plunger for a door handle which reduces release efforts and increases wear. A further objective of the present invention is the provision of an improved door handle having a metal plunger with a plastic link. Still another objective of the present invention is the provision of an improved plunger assembly with a plunger made from a wear-resistant material and a link made from a low-coefficient of friction material. Another objective of the present invention is the provision of an improved plunger assembly for a door handle which is economical to manufacture and durable in use. SUMMARY OF THE INVENTION The composite plunger assembly of the present invention provides an improved door handle. The assembly includes a metal plunger and a plastic link. The plunger includes a recess to receive a finger on the link such that the plunger and link are connected for movement between an extended position and a retracted position. The link includes a recess defining a shoulder for engagement by a pivot plate on the door handle. Actuation of the door handle pivots the plate so as to slide the link and plunger assembly to a retracted position from the normally biased extended position. The plastic link provides for reduced friction between the link and the housing, thereby minimizing the release effort required by a user of the handle. The plastic link also provides increased wear resistance between the pivot plate and the link for longer life and reduced effort. The metallic plunger has a hardness which minimizes wear when engaging the striker plate in the frame surrounding the door in which the handle is mounted. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the door handle having the improved plunger assembly of the present invention. FIG. 2 is a rear elevation view of the door handle. FIG. 3 is a sectional view along lines 3-3 of FIG. 2 and showing the composite plunger assembly of the present invention. FIG. 4 is a view similar to FIG. 3 showing a prior art plunger for a door handle. FIG. 5 is a side elevation view of the plunger link. FIG. 6 is a top plan view of the plunger link. FIG. 7 is a side elevation view of the plunger. FIG. 8 is a top plan view of the plunger. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a door handle 10 having the improved plunger assembly 12 of the present invention. The handle 10 includes a housing 14, with a paddle 16 pivotally mounted in the housing for movement between the normal closed position shown in FIG. 1 and a raised open position. The plunger assembly 12 is slidably mounted within a plunger tunnel 18, which is preferably formed as a part of the housing 14. The plunger assembly 12 is moveable between the extended position shown in FIG. 1, and a retracted position. A pivot plate 20 is pivotally mounted on the rear of the housing 14. The paddle 16 engages and drives a pivot arm 22 on an axle (not shown). The axle extends through a hole in the housing 14 so that the arm 22 engages a first arm 24 on the pivot plate 20. The present invention is directed towards the plunger assembly 12. As seen in FIGS. 3 and 5-8, the plunger assembly 12 includes a plunger 26 and a plunger link 28. The plunger 26 includes a beveled surface 27 adapted to engage a striker plate (not shown) or the frame surrounding the door (not shown) in which the handle 10 is mounted. The composite construction of the plunger 26 and the link 28 is a light press-fit assembly, with the plunger tunnel 18 maintaining the plunger 26 and the link 28 together. The plunger includes a recess 30 which receives a finger 32 on the link 28 so as to connect the plunger 26 and the link 28 together. The link 28 includes a recess 34 defining a shoulder 36 which is engaged by a second arm 38 on the pivot plate 20. Thus, upon actuation of the paddle 16, the pivot plate 20 rotates (in a counterclockwise position as seen in FIG. 2) such that the arm 38 pulls the plunger assembly 12 to a retracted position with the plunger 26 within the plunger tunnel 18, so that the door (not shown) in which the handle 10 is mounted can be opened. The paddle 16, pivot plate 20, and plunger assembly 12 are each spring biased, such that upon release of the paddle 16, the pivot plate 20 rotates in a clockwise direction (as shown in FIG. 2) and the plunger assembly 12 slides to the extended position shown in FIGS. 1 and 2. The plunger assembly 12 has a composite construction of a metallic plunger 26 and a plastic link 28. The plunger 26 is preferably made of zinc. The metallic plunger 26 has a hardness which provides wear-resistance to the repeated engagement with a striker plate or frame surrounding the door. The plastic link 28 provides for reduced friction, which reduces the release effort required by a person actuating the paddle 16. Also, the plastic material of the link 28 minimizes wear from engagement with the second arm 38 of the pivot plate 20. Therefore, the overall life of the plunger assembly 12 is extended. The plunger assembly 12 is biased to the extended position by a spring 39 mounted in the rear end of the plunger tunnel 18, and as seen in FIG. 3. FIG. 4 shows a prior art one-piece plunger 40, which have been known to be made from either metal or plastic. The prior art metallic plunger 40 has increased friction, which increases the release effort required by a user. Also, the metallic plunger 40 has increased wear at the engagement with the pivot plate arm 38, which reduces the life of the plunger 40. For plastic plungers 40, there is excessive wear between the plunger and the strike plate, which shortens the plunger life. The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives. | <SOH> BACKGROUND OF THE INVENTION <EOH>Door handles, such as those used on vehicles, including ingress and egress doors as well as compartment doors, such as on an RV, typically include a housing with a paddle pivotally mounted on the housing, and a pivot plate pivotally mounted on the rear of the housing for actuation by the paddle. A plunger is mounted on the housing for movement between a normally extended position to hold the door closed and a retracted position to allow opening of the door. Actuation of the handle causes the pivot plate to slide the plunger from the extended position to the retracted position. The frame surrounding the door handle typically includes a striker plate or surface which is struck by a beveled edge on the plunger as the door moves from the opened position to the closed position, with the plunger extending into a recess or behind the striker plate to retain the door in the closed position. Prior art plungers have a one-piece construction, and have been made of both metal and plastic. A metal plunger has increased friction, which increases the release efforts required to open the door. Also, a metal plunger has increased wear with the pivot plate, which is normally made of steel, so that the plunger has a reduced life expectancy. In comparison, a plastic plunger has a reduced coefficient of friction, as compared to a metal plunger, so as to minimize the release efforts required to open the door, but has poor wear caused by repeated engagement with the striker plate so as to reduce the life of the plastic plunger. Accordingly, the primary objective of the present invention is the provision of an improved plunger assembly for a door handle which has reduced friction and increased life. Another objective of the present invention is the provision of a composite plunger for a door handle which reduces release efforts and increases wear. A further objective of the present invention is the provision of an improved door handle having a metal plunger with a plastic link. Still another objective of the present invention is the provision of an improved plunger assembly with a plunger made from a wear-resistant material and a link made from a low-coefficient of friction material. Another objective of the present invention is the provision of an improved plunger assembly for a door handle which is economical to manufacture and durable in use. | <SOH> SUMMARY OF THE INVENTION <EOH>The composite plunger assembly of the present invention provides an improved door handle. The assembly includes a metal plunger and a plastic link. The plunger includes a recess to receive a finger on the link such that the plunger and link are connected for movement between an extended position and a retracted position. The link includes a recess defining a shoulder for engagement by a pivot plate on the door handle. Actuation of the door handle pivots the plate so as to slide the link and plunger assembly to a retracted position from the normally biased extended position. The plastic link provides for reduced friction between the link and the housing, thereby minimizing the release effort required by a user of the handle. The plastic link also provides increased wear resistance between the pivot plate and the link for longer life and reduced effort. The metallic plunger has a hardness which minimizes wear when engaging the striker plate in the frame surrounding the door in which the handle is mounted. | 20040706 | 20070619 | 20060112 | 92207.0 | E05C112 | 0 | ESTREMSKY, GARY WAYNE | COMPOSITE DOOR LOCK PLUNGER | SMALL | 0 | ACCEPTED | E05C | 2,004 |
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10,885,545 | ACCEPTED | Compositions of plant carbohydrates as dietary supplements | Compositions of plant carbohydrates for dietary supplements and nutritional support for promotion and maintenance of good health. Defined nutritionally effective amounts of one to eleven essential saccharides, glyconutrients, are used in various inventive compositions as dietary supplements. The dietary composition herein can include phytonutrients, vitamins, minerals, herbal extracts, and other non-toxic nutrients. The glyconutritional dietary supplement herein provides essential saccharides which are the building blocks of glycoproteins. These compositions, when administered orally or topically, have been found to improve the well being of mammals suffering from a variety of disorders. | 1. A dietary supplement composition, comprising: nutritionally effective amounts of at least six saccharides selected from the group consisting of galactose, glucose, mannose, xylose, acetylated mannose, N-acetylneuraminic acid, fucose, N-acetylgalactosamine, N-acetylglucosamine, arabinose, glucuronic acid, galacturonic acid, iduronic acid and arabinogalactan. 2. A dietary supplement composition according to claim 1, wherein said saccharides are predigested from an oligomeric or polymeric form of saccharides as found in at least one of gum tragacanth, guar gum, grain flour, rice flour, sugar cane, beet sugar, potato, milk, agar, algin, locust bean gum, psyllium, karaya gum, seed gums, Larch tree extract, aloe vera extract, gum ghatti, starch, cellulose, degraded cellulose, fructose, high fructose corn syrup, pectin, chitin, acacia, gum arabic, alginic acid, carrageenan, dextran, xanthan gum, chondroitin sulfate, sucrose, acetylated polymannose, maltose, glucan, lentinan, mannan, levan, hemi-cellulose, inulin, fructan, and lactose. 3. A dietary supplement composition according to claim 1, further comprising a nutritionally effective amount of beta sitosterol. 4. A dietary supplement composition according to claim 1, further comprising a nutritionally effective amount of dioscorea complex. 5. A dietary supplement composition according to claim 4, wherein said composition comprises from about 50 to about 99.9999 weight percent of said saccharides and from about 0.0001 to about 50 weight percent of said dioscorea complex. 6. A dietary supplement composition according to claim 4, wherein said composition comprises from about 30 to about 99.99 weight percent of said saccharides and from about 0.01 to about 70 weight percent of said dioscorea complex. 7. A dietary supplement composition according to claim 4, wherein said composition comprises from about 60 to about 90 weight percent of said saccharides and from about 10 to about 40 weight percent of said dioscorea complex. 8. A dietary supplement composition according to claim 4, wherein said composition comprises about 80 weight percent of said saccharides and about 20 weight percent of said dioscorea complex. 9. A dietary supplement composition according to claim 1, further comprising a nutritionally effective amount of a blend of freeze-dried and powdered raw fruits and vegetables. 10. A dietary supplement composition according to claim 9, wherein said blend of freeze-dried and powdered raw fruits and vegetables comprises: broccoli, brussel sprouts, cabbage, carrot, cauliflower, garlic, kale, onion, papaya, pineapple, tomato and turnip. 11. A dietary supplement composition according to claim 9, wherein said composition comprises from about 0.01 to about 99.999 weight percent of said saccharides and from about 0.001 to about 99.99 weight percent of said blend of freeze-dried and powdered raw fruits and vegetables. 12. A dietary supplement composition according to claim 9, wherein said composition comprises from about 1 to about 80 weight percent of said saccharides and from about 20 to about 99 weight percent of said blend of freeze-dried and powdered raw fruits and vegetables. 13. A dietary supplement composition according to claim 9, wherein said composition comprises from about 5 to about 50 weight percent of said saccharides and from about 50 to about 95 weight percent of said blend of freeze-dried and powdered raw fruits and vegetables. 14. A dietary supplement composition according to claim 1, further comprising nutritionally effective amounts of xanthines and herbal body-toning agents. 15. A dietary supplement composition according to claim 1, further comprising a nutritionally effective amount of melatonin. 16. A dietary supplement composition according to claim 1, further comprising an effective amount of a saccharide bioabsorption aid. 17. A dietary supplement composition according to claim 16, wherein said bioabsorption aid comprises soy lecithin. 18. A dietary supplement composition according to claim 1, further comprising nutritionally effective amounts of a dioscorea complex and a blend of freeze-dried and powdered raw fruits and vegetables. 19. A dietary supplement composition according to claim 1, further comprising nutritionally effective amounts of non-toxic vitamins and minerals. 20. A dietary supplement composition according to claim 19, wherein: said vitamins are selected from the group consisting of A, B1, B12, B2, B6, beta carotene, bioflavanoids, biotin, C, choline, D, E, folic acid, inositol, K, niacinamide, para-aminobenzoic acid, pantothenic acid and combinations thereof; and said minerals are selected from the group consisting of boron, calcium, copper, GTF chromium, iodine, iron, magnesium, manganese, molybdenum, potassium, selenium, silicon, vanadium, zinc and combinations thereof. 21. A dietary supplement composition according to claim 1, further comprising an herbal extract or plant extract of broccoli, brussel sprouts, cabbage, carrot, cauliflower, garlic, kale, onion, papaya, pineapple, tomato, asparagus, mushroom, parsnip, radish and turnip. 22. A dietary supplement composition according to claim 21, wherein said composition comprises from about 25 to about 99.999 weight percent of said saccharides and from about 0.001 to about 75 weight percent of said herbal or plant extract. 23. A dietary supplement composition according to claim 21, wherein said composition comprises from about 10 to about 90 weight percent of said saccharides and from about 10 to about 90 weight percent of said herbal or plant extract. 24. A dietary supplement composition, comprising: a nutritionally effective amount of acetylated mannose and at least five saccharides selected from the group consisting of galactose, glucose, mannose, xylose, N-acetylneuraminic acid, fucose, N-acetylgalactosamine, N-acetylglucosamine, arabinose, glucuronic acid, galacturonic acid, iduronic acid and arabinogalactan. 25. A dietary supplement composition for the modification of behavior in alcohol dependent mammals, comprising nutritionally effective amounts of acetylated mannose, gum ghatti, gum tragacanth, glucosamine, corn starch and arabinogalactan. 26. A dietary supplement composition for reducing side-effects in mammals receiving biologically effective agents that cause such side-effects, comprising nutritionally effective amounts of acetylated mannose, gum ghatti, gum tragacanth, glucosamine, corn starch and arabinogalactan. 27. A dietary supplement composition according to claim 26, wherein said dietary supplement composition reduces the undesired side-effects of said agents on the central nervous system. 28. A dietary supplement composition according to claim 26, wherein said dietary supplement composition reduces the side-effects of methylphenidate in a mammal suffering from attention-deficit hyperactivity disorder. 29. A dietary supplement composition for providing essential components for glycoproteins in a mammal comprising nutritionally effective amounts of tragacanth gum, guar gum and rice flour. 30. A dietary supplement composition according to claim 29, wherein said composition further comprises a flowing agent and a lubricant. 31. A dietary supplement composition according to claim 29, wherein said tragacanth gum, guar gum and rice flour are present in said composition in a weight ratio of 10:1:20. 32. A dietary supplement composition for providing essential components for glycoproteins in a mammal comprising nutritionally effective amounts of tragacanth gum, gum ghatti, arabinogalactan and aloe vera extract. 33. A dietary supplement composition according to claim 32, wherein said composition comprises 20 percent by weight of said tragacanth gum, 20 percent by weight of said gum ghatti, 40 percent by weight of said arabinogalactan, and 20 percent by weight of said aloe vera extract. 34. A dietary supplement composition for providing essential components for glycoproteins in a mammal comprising nutritionally effective amounts of aloe vera extract, gum ghatti, tragacanth gum, glucosamine, corn starch and arabinogalactan. 35. A dietary supplement composition according to claim 34, wherein said composition comprises 10 percent by weight of said aloe vera extract, 10 percent by weight of said gum ghatti, 10 percent by weight of said tragacanth gum, 10 percent by weight of said glucosamine, 12 percent by weight of said corn starch and 48 percent by weight of said arabinogalactan. | CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of application Ser. No. 09/242,215 filed Feb. 8, 1999, the entire disclosure of which is incorporated herein by reference, which is a U.S. national phase filing of International Application No. PCT/US97/13379 filed Aug. 4, 1997, which claims the priority of U.S. Provisional Application No. 60/022,467 filed Aug. 9, 1996, the entire disclosure of which is incorporated herein by reference, U.S. Provisional Application No. 60/030,317 filed Nov. 1, 1996, the entire disclosure of which is incorporated herein by reference, and U.S. Provisional Application No. 60/057,017 filed Jul. 24, 1997, the entire disclosure of which is incorporated herein by reference. This application is related to prior filed application Ser. No. 10/294,121 filed November 14, 2002, the entire disclosure of which is incorporated herein by reference, which is a divisional application of the above-identified application Ser. No. 09/242,215. This application is also related to prior filed Applications Ser. Nos. 10/797,344 and 10/797,760, both filed Mar. 10, 2004, the entire disclosures of which are incorporated herein by reference, which are continuation applications of the above-identified application Ser. No. 09/242,215. FIELD OF THE INVENTION This invention pertains to the field of dietary supplements and nutritional support for promotion and maintenance of good health. More specifically, the invention relates to compositions of carbohydrates a dietary supplements that are essential for the production of correctly structured and, therefore, properly functioning glycoproteins. DESCRIPTION OF THE PRIOR ART AND OTHER INFORMATION The term mucus was first used in the 1700s. By 1805, Bostok realized that mucus was composed of protein that differed from albumin and gelatin. In 1865, Eichwald showed that mucins contained carbohydrate moieties. In 1877, Hoppe-Seyler discovered that mucins were high in sialic acid content. In 1882, Landwehr showed that plant gums, a type of mucin, contain more than one monosaccharide. With the advent of more modern methods, these monosaccharides were isolated and characterized. In 1888, Harmarsten showed that the saccharides in mucins were joined by a covalent bond; Harmarsten was the first to use the term “glykoproteide” (or glycoprotein in English). Fischer and Leuchs discovered high concentrations of mannose in mucus in 1902. Hayworth, in 1939, discovered N-acetylglucosamine and Bierry discovered galactose in 1930. Meyer discovered fucose in 1958 (Gottschalk, Glycoproteins, 1972). Proteins were originally thought to be the primary “communication” molecules of the body. The biotechnology revolution began as an attempt to create new drugs based upon proteins which are made up of various combinations of amino acids. However, since amino acids can only bind to each other through an amide bond, the number of secondary configurations possible with proteins is limited. Indeed, only one secondary configuration is possible per dipeptide. However, many more functions are performed by the body than can be accounted for by the number of molecular configurations possible with proteins. Several years ago a theoretical mathematician calculated the number of configurations possible with proteins and discovered that another mechanism, yet unknown, had to be responsible for performing most of the communication functions of the body. It is now known that this mechanism involves carbohydrates. In contrast to the simpler proteins, more molecular configurations are possible with the more complex carbohydrate molecule, e.g., a hexose has six chiral centers each of which has two isomeric forms and each of which has a hydroxyl group as a binding site for other molecules. Thus, while only 24 oligopeptide configurations are possible with four amino acids, more than 100,000 different oligosaccharide configurations are possible with four sugars (Stryer et al., Biochemistry 1995; p 477). Science has recently shown that glycoproteins play a key role in all cellular communication. Many of the cytokines, i.e. cellular messenger agents, do not function properly without an attached glycosyl moiety. The body hydrolyzes complex polysaccharides such as plant carbohydrates into various monosugars and restructures them into oligosaccharides that are then used by the body to build the glycoproteins required by cytokines for cellular communication and, thus, for good health. With the advent of improved analytical techniques and more powerful computers, characterization of glycoproteins increased rapidly after the 1960s. By the mid 1980s, the mechanism of the orderly synthesis of glycoproteins in the endoplasmic reticulum and Golgi apparatus had been determined. The actual oligosaccharide conformations of many glycoproteins is now known. Increasing interest in glycobiology has been precipitated by recent findings that cell surface carbohydrates are critically involved in cell adhesion and, thus, in cell-cell interaction. Specifically, three new mechanistic concepts have been discovered. First, structural studies in glycoproteins and glycolipids have revealed the existence of carbohydrates which are unique to certain cell types. This concept is crucial to understanding cell surface carbohydrates as cell-type specific recognition molecules. A second concept was developed from new information regarding lectins, which have sugar-binding proteins. In the 1970s it was learned that glycoproteins were removed rapidly from the blood when their sialic acid, i.e. N-acetylneuraminic acid, containing branches were removed. Further studies revealed that this rapid clearance was caused by asialoglycoproteins binding to lectins that recognize terminal galactose. Once animal cells were known to have lectins, a large number of lectins were characterized, and a dedicated section in the amino acid sequence that is responsible for the carbohydrate recognition domain in the lectins was discovered. This discovery was critical to understanding carbohydrate-binding capability in cell-cell interactions. Thus, cellular communication was recognized at the molecular level. The third concept resulted from studies regarding the isolation and characterization of the glycosyltransferases that form carbohydrates. These studies showed that carbohydrate moieties are usually built one by one, and each reaction is carried out by a glycosyltransferase that forms only a specific linkage. The advent of molecular biology in this field has enabled scientists to manipulate carbohydrate expression and study glycoprotein function. Based on critical advances in this field, the most recent studies demonstrated that oligosaccharides uniquely present in leukocytes act as ligands for adhesive molecules in endothelia and platelets. When these adhesive molecules, known as selecting, were cloned, it was discovered that they contained carbohydrate recognition domains. Thus, studies on cell-type specific carbohydrates and animal lectins corroborated each other. Moreover, these studies were preceded by the findings that lymphocyte-endothelial interaction is dependent upon carbohydrates. Given the above, research directed toward the synthesis of drugs that would correct malformation of glycoproteins on cell surfaces began. After the carbohydrate ligand sialyl-Lex was identified, pharmaceutical companies soon synthesized it for therapeutic purposes. This line of research has since become much easier because enzymatic synthesis of carbohydrates is now possible thanks to the availability of glycosyltransferases generated by cloned cDNAs (Fukuda et al., Glycobiology, 1994). The synthesis of all proteins and glycoproteins is controlled by somatic genes embodied in the chromosomes of a cell. The coding information expressed in nucleic acids (DNA) controls all cellular functions, including general body defense, regeneration, remodeling and healing. Though DNA provides the blueprint, the cellular components cannot be built correctly without the required building blocks. As discussed above, cytokines are key components used for intracellular instruction to carry out the body's vital functions. However, many cytokines do not function properly without an attached glycosyl moiety. Table 1 lists some of the known physiological functions served by glycoproteins. Table 2 lists some of the specific known functions that the oligosaccharide branches or chains of glycoproteins perform. TABLE 1 Some known functions served by glycoproteins: Function Glycoproteins Structural molecule Collagens Lubricant and protective Mucins agent Transport molecule Transferrin, ceruloplasmin Immunologic molecule Immunoglobulins, histocompatibility antigens Hormone Chorionic gonadotropin, thyroid-stimulating hormone (TSH) Enzyme Various, e.g., alkaline phosphatase Cell attachment- Various proteins involved in cell-cell (e.g., recognition site sperm-oocyte), virus-cell, bacterium-cell, and hormone-cell interactions Interact with specific Some lectins carbohydrates TABLE 2 Some known functions of the oligosaccharide chains of glycoproteins: Modulate physicochemical properties, e.g., solubility, viscosity, charge, and protein denaturation Protect against proteolysis from within and outside the cell Affect proteolytic processing of precursor proteins to smaller products Are involved in biologic activity, e.g., of human chorionic gonadotropin (hCG) Affect insertion of protein into membranes, intracellular protein migration, and protein sorting and secretion Affect embryonic development and differentiation Affect metabolism May affect sites of metastases selected by cancer cells In summary, various processes of the cell are regulated or affected by correctly structured and, therefore, properly functioning glycoproteins. Despite the above discussed current scientific knowledge concerning the importance of glycoproteins to cell-cell communication and the importance of carbohydrates in the formation of glycoproteins, and despite the fact that diet is the source of a majority of carbohydrates, the fields of glycobiology and nutrition have never been adequately investigated together. Although current nutrition textbooks stress the importance of essential vitamins, minerals, proteins (amino acids) and fats in great detail, sugars are currently recognized only as a source of energy (Shils et al., 1994)--not as substances essential to glycoprotein production for good health. For example, Shils et al. disclose that the principal sources of dietary carbohydrates are: 1) maize, nice, wheat, and potato which yield starches comprising glucose; 2) sugar cane and beet sugar which yield fructose and glucose; and 3) milk which yields galactose and glucose (Shils et al., Modern Nutrition in Health and Disease, (1994)). By way of contrast, Harper's Biochemistry (Murray et al., 1996) lists eight and Principles of Biochemistry, Vol II (Zubay et al., 1995) lists eleven monosaccharides commonly found in the oligosaccharide chains of cellular glycoproteins. Thus, of the approximate 200 monosaccharides found in nature, these eleven are believed to be important toward maintaining good health in mammals. These eleven saccharides include galactose, glucose, mannose, N-acetylneuraminic acid, fucose, N-acetylgalactosamine, N-acetylglucosamine and xylose (Murray et al., Harper's Biochemistry 1996) as well as iduronic acid, arabinose and glucuronic acid, (Zubay et al., Principles of Biochemistry, Vol II, 1995). The structures of these carbohydrates are disclosed in Stryer's Biochemistry (Stryer, 1995) and the Merck Index, 12th Edition, 1996. Recognizing this, scientists are currently trying, as yet with limited success, to synthetically attach glycosyl moieties to cytokines and other proteins. In fact, NIH has launched a project to develop methods to synthesize the glyco portion currently missing from their genetically engineered proteins. These synthetically produced cytokines have so far demonstrated disappointing results. Many challenges remain in this area. Scientists must first learn: 1) how to synthesize the glyco portion, 2) how to attach the glyco portion to the protein, and then 3) how to get the correct glycoproteins in the right concentrations to the right places in the body so as to facilitate good health. For centuries, people of diverse cultures from around the world have utilized plants and herbs in the treatment of a wide variety of disorders in mammals. Specifically, formulations including poultices, teas, powders, pastes, extracts, plant or herb parts, plant or herbal extracts, lotions, creams, salves, troches, and others have been used. It is also now well recognized that much of the world's farm lands have been depleted of essential minerals required to sustain life, thus requiring the widespread use of vitamin, mineral and dietary supplements. A recent discovery concerns the importance of plant chemicals (phytochemicals) that are found in vine-ripened fruits and vegetables but are not found in those that are not vine-ripened. To provide these necessary, yet undefined, phytonutrients or phytonutritionals, as defined below, to the diet, some companies have begun supplying dietary supplements of freeze-dried, vine-ripened fruits and vegetables. Nutritionists have developed hundreds of dietary supplement formulations in an effort to provide essential dietary components and facilitate and promote good health in mammals. However, fraudulent product claims regarding the treatment of physiological disorders are pervasive in the industry, and modern farming methods which focus on volume rather than nutritional value of crop production have led to crops having reduced dietary value that are missing essential dietary components. Despite the extremely large number of dietary supplements available on store shelves today, the dietary needs of humans are still not being met. Many of such commercially available dietary supplements do not appear to provide any significant nutritional benefit. The present inventors believe such prior products suffer any one or more of the following disadvantages: a) they do not include the correct nutritional product(s); and b) their nutritional products are not well absorbed by a person taking them. Thus, while scientists are beginning to recognize that other phytochemicals are required for good health, and others have previously recognized the utility of plants and herbs in the treatment of disorders, none of the known art suggests or discloses the invention as claimed herein. A need remains for non-pharmaceutical based dietary supplement formulations which provide essential saccharides that are the building blocks of glycoproteins and which promote good health in mammals. SUMMARY OF THE INVENTION It is an object of the present invention to provide a dietary supplement which promotes good health by providing to a mammal essential saccharides which are the building blocks of glycoproteins. It has now been demonstrated herein by the present inventors that inclusion of these essential saccharides, as by supplementation of a diet with a dietary supplement containing the same, in the diets of mammals promotes good health. Although not intended to be limited to a particular mechanism of action, these essential saccharides are believed to be absorbed into the mammal's body and utilized in the formation of glycoproteins. By so providing these essential saccharides, the mammal's body does not have to spend energy unnecessarily catabolizing these essential saccharides and can therefore spend its energy providing for other physiological needs such as enhancement of the immune system to ward off, combat and/or ameliorate a wide range of physiological disorders. Thus, the present invention overcomes the disadvantages and drawbacks of the prior art. One aspect of the present invention is directed to the use of various compositions of carbohydrates, i.e., glyconutritionals or glyconutrients, as dietary supplements which supplement a mammal's diet with sugars essential to glycoprotein and/or glycolipid production and thereby promote good health. In one embodiment, the present invention is directed to nutritional supplements including a defined amount of at least one of the eleven carbohydrates that are essential for the production of correctly structured and, therefore, properly functioning glycoproteins and/or glycolipids in a mammal. While some of these eleven sugars are readily available in common food sources, others are quite rare. Accordingly, a first embodiment of the invention provides a dietary supplement for providing nutritional product saccharides which are essential components of glycoproteins in a mammal, said dietary supplement comprising a nutritionally effective amount of at least one saccharide, in monomeric, oligomeric or polymeric and derivatized or underivatized form, selected from the group consisting of: galactose, glucose, mannose, N-acetylneuraminic acid, fucose, N-acetylgalactosamine, N-acetylglucosamine, xylose, arabinose, glucuronic acid, galacturonic acid, iduronic acid, arabinogalactan, acetylated mannose, glucosamine and galactosamine. In other embodiments of the invention, the dietary supplement comprises nutritionally effective amounts of at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten or at least eleven saccharides, in monomeric, oligomeric or polymeric and derivatized or underivatized forms selected from the above listed group. Since some of these saccharides have ionizable groups, the invention contemplates all known non-toxic salt forms thereof. The monomeric, oligomeric or polymeric and derivatized or underivatized forms of these saccharides can be obtained from a wide variety of sources, such as for example, gum tragacanth, guar gum, grain flour, rice flour, sugar cane, beet sugar, potato, milk, agar, algin, locust bean gum, psyllium, karaya gum, seed gums, Larch tree extract, aloe vera extract, gum ghatti, starch, cellulose, degraded cellulose, fructose, high fructose corn syrup, pectin, chitin, acacia, gum arabic, alginic acid, carrageenan, dextran, xanthan gum, chondroitin sulfate, sucrose, acetylated polymannose, maltose, glucan, lentinan, mannan, levan, hemi-cellulose, inulin, fructan, and lactose. Other embodiments of the invention can comprise phytochemicals or phytonutritionals derived from ripened and freeze-dried fruits and vegetables, dioscorea complex, herbal extracts, herbal body-toning agents, beta sitosterol, melatonin, soy lecithin, vitamins, or minerals. In another embodiment of the present invention, the compositions include predigested forms of at least one of the eleven essential carbohydrates. This can include one or all of the following: 1) physical digestion such as shearing or treatment with ultrasound, 2) chemical digestion such as enzymatic digestion, and acid or base hydrolysis, and 3) biological digestion with microbes such as bacteria, fungi or molds. In another aspect, the present invention is a dietary supplement for the modification of behavior in alcohol dependent mammals comprising nutritionally effective amounts of the natural and/or synthetic monomeric, oligomeric and/or polymeric forms of acetylated mannose, gum ghatti, gum tragacanth, glucosamine, corn starch and arabinogalactan. In a particular embodiment, the dietary supplement will reduce the craving for alcohol in an alcohol dependent mammal being administered the supplement. In another particular embodiment, the dietary supplement will improve the overall well being of the alcohol dependent mammal by reducing at least one of depression and anger or increasing at least one of cognition, energy and positive outlook. In yet another aspect, the present invention is a dietary supplement for the reduction of undesired side-effects in mammals receiving biologically effective agents that cause said side-effects, said dietary supplement comprising nutritionally effective amounts of the natural and/or synthetic monomeric, oligomeric and/or polymeric forms of acetylated mannose, gum ghatti, gum tragacanth, glucosamine, corn starch and arabinogalactan. In a particular embodiment, the dietary supplement will reduce the undesired side-effects of central nervous system drugs. In a more particular embodiment, the dietary supplement will reduce the undesired side-effects of methylphenidate in a mammal suffering from attention-deficit hyperactivity disorder and receiving methylphenidate. DETAILED DESCRIPTION The body of a mammal hydrolyzes or metabolizes complex polysaccharides, such as plant carbohydrates, into various monosaccharides and subsequently forms oligosaccharides therefrom that are then used by the body to build the glycoproteins required by cytokines for cellular communication. As used herein, the term “phytochemical” refers to plant synthesized molecules, found in food, or plant tissue in a complex organic matrix, which are minimally altered by processing from how they occur in nature. As used herein, the term “nutraceutical” refers to a non-toxic, nutrient of plant, mineral or animal origin, that has health promoting activity and that can be standardized and supplied as a dietary supplement to improve the nutritional quality of a balanced general diet. A nutraceutical is also a glyconutrient or phytonutrient. As used herein, the terms “glyconutritional” or “glyconutrient” refer to complex carbohydrates or saccharides or simple sugars that are synthesized in nature and are necessary for the biochemical synthesis of various classes of communication and signal molecules that may be free in interstitial cellular fluids, active in cell to cell communication (i.e., cytokines, growth factors, etc.), or constitute the molecular configuration comprising foci of highly specific molecular activity of cell membranes (i.e., receptor sites, ion-transport channels, antigenic identification, and the like). As used herein, the terms “phytonutritional” or “phytonutrient” refer to naturally synthesized molecules found only in plants that are produced to protect the plant's cells. Phytonutrients primarily have antioxidant, free-radical scavenger and vital micronutrient activity. These molecules, supplied through dietary supplementation, are found in mature plant tissues, and are most concentrated in seed coats and fruiting tissues surrounding the seed. In mammalian tissues, these molecules when supplied in the diet, are active in optimizing the biochemistry, immunology and physiology in the cellular micro-environment. As used herein, the term “dioscorea complex” refers to an extract of dioscorea species (Mexican yam) providing a natural pre-cursor, dietary nutrient, diosgenin, a complex, six-ring, cyclic-carbon molecule that contains the molecular scaffold (perhydrocyclopentanophenanthrene) upon which mammalian adrenal and gonadal hormones are naturally synthesized. Providing this complex molecule in the diet can support optimal hormone balance, while maintaining normal physiological control mechanisms. This dietary supplement component has the potential to improve metabolic regulation of virtually every functioning cell in the body. As used herein, the term “herbal extract” refers to phytochemicals that are produced in plant tissues and that can be extracted by water, polar, or petroleum solvents, and that have some degree of beneficial health or therapeutic activity. Most herbal agents can be toxic, especially when concentrated, but are generally safe when utilized in their more traditional manner in teas and poultices as a “folk medicinal for the treatment of disease and promotion of good health. As used herein, the term “herbal body-toning agent” refers to substances that have been observed by the inventors to reduce and reverse elastic tissue and collagen fiber damage caused by aging or sun-damage as evidenced by a restoration of skin turgor and elasticity which effectively reduces or eliminates wrinkles, sagging, hyperpigmentation and reversal of other undesirable elements of lost cosmetic appearance. The carbohydrates included in the dietary supplement of the invention are available from a wide variety of natural and synthetic sources such as shrubs, trees, plants, yeasts, fungi, molds, gums, resins, starch and cellulose derivatives and natural mucin sources. Specifically, some of the natural sources include: (a) shrub or tree exudates which contain acacia, karaya, tragacanth, or ghatti; (b) marine gums which include agar, algin, or carrageenan; (c) seed gums which include guar, locust bean, or psyllium; (d) plant extracts which contain pectins or acetylated polymannose; (e) starch and cellulose derivatives such as hetastarch, carboxymethylcellulose, ethylcellulose, hydroxypropyl methylcellulose, methylcellulose, oxidized cellulose; and microbial gums which contain dextrans, xanthan. (Tyler et al., 1981) However, it should be recognized that the composition of the invention is not intended to be limited by the source from which the respective carbohydrates are obtained. The saccharides of the invention can be found in nature as mono-, oligo- and/or polysaccharides. Thus, the compositions of the invention can contain the saccharides in their monomeric, oligomeric and/or polymeric forms. Table 3 below lists some of the known natural sources for the saccharides of the invention. TABLE 3 Natural sources of saccharides. Source Carbohydrate Corresponding Saccharide(s) gum tragacanth galacturonic acid, galactose, fucose, xylose, arabinose, rhamnose guar gum mannose and galactose (1:2 molar ratio) rice or grain flour glucose LAREX B-1000 polyarabinogalactan (Larch tree extract) MANAPOL ® acetylated mannose based polymer (aloe vera extract) gum ghatti arabinose, galactose, mannose, xylose, glucuronic acid (10:6:2:1:2 molar ratio) starch glucose pectin galacturonic acid chondroitin sulfate N-acetylgalactosamine chitin N-acetylglucosamine acacia, gum arabic arabinose, galactose, glucuronic acid alginic acid mannosyluronic acid, gulosyluronic acid carrageenan galactose, 3,6-anhydrogalactose dextran glucose xanthan gum glucose, mannose, glucuronic acid It is well recognized in the art that the saccharides listed above with their corresponding source carbohydrates are present in particular amounts in nature as exemplified by the indicated molar ratios for the saccharides in gum ghatti and guar gum. The relative amounts or ratios of saccharides in natural carbohydrates is readily determined using conventional extraction or analytical methods or can be obtained from literature sources commonly used in the art. As used herein, the term “carbohydrate” is used interchangeably with the terms “saccharide”, “polysaccharide”, “oligosaccharide” and “sugar” the definitions of which are well known in the art of carbohydrate chemistry. Although the compositions of the invention are intended to include at least one of the eleven essential saccharides, it should be noted that the saccharides can be in the form of mono-, oligo- and/or polysaccharides, e.g. a composition containing gum tragacanth and guar gum will be considered as containing galacturonic acid, fucose, xylose, arabinose, rhamnose, mannose and galactose. Therefore, by controlling the amount of particular gums in a given dietary supplement, one can control the amount of the respective saccharides in said dietary supplement. Although the present invention includes the above cited eleven essential saccharides, it should be noted that other saccharides, nutritional compounds or biologically active or inert compounds can be included in the dietary supplement of the invention. Such other nutritional compounds include any one or more of phytonutrients, dioscorea complex, plant extracts, herbal extracts, plant parts, herbal components, vitamins or minerals. These nutritional compounds can be added to the dietary supplement of the invention, or they can be provided separately to a mammal being administered said dietary supplement. For example, a person receiving the glyconutrient-containing dosage form of the invention can also receive a phytonutrient in either the same or a separate dosage form. Inert compounds can include flavors, fillers, lubricants, buffers, gels, binders, excipients, carriers and/or other such compounds that facilitate the formulation or administration of the inventive dietary supplement. All of the glyconutrient-containing dietary supplement compositions of the invention, even those containing additional compounds, agents or other substances, can be obtained directly from MANNATECH™ (Coppell, Tex.). Dioscorea complex is available from Ayusherbs (Japan). When dioscorea complex is included in the dietary supplement of the invention, the ratio of dioscorea complex to total essential saccharide can range from about 0.0001/99.9999 to about 50/50 on a weight percent basis. In particular embodiments, the dioscorea complex to total essential saccharide ratio ranges from about 0.01-70/99.99-30 or about 10-40/90-60 or about 20/80. Phytonutrients are available from a wide variety of manufacturing sources such as Cap-Tab (U.S.) or they can be added by freeze-drying and grinding ripe fruits and/or vegetables to form a powder which can then be added to or provided along with the dietary supplement of the invention. Such fruits and vegetables can be selected from all known fruits and vegetables but, in particular exemplary embodiments, include broccoli, brussel sprouts, cabbage, carrot, cauliflower, garlic, kale, onion, papaya, pineapple, tomato and turnip. These phytonutrients can be formulated in powder-containing caplet or capsule forms or in a base of gelatin and natural fruit fructose, optionally containing added flavors. When a phytonutrient is included in the dietary supplement of the invention, the ratio of total phytonutrient to total glyconutrient can range from about 0.001/99.999 to about 99.99/0.01 on a weight percent basis. As used herein, Phyto-1 refers to a dietary supplement comprising Glyco-1 (see Example 5), and freeze-dried raw fruits and vegetables. In particular embodiments, the phytonutrient to total glyconutrient ratio ranges from about 20-99/80-1 or about 50-95/50-5. There are many plant and herbal extracts with suspected or demonstrated nutritional value which can promote good health and can be incorporated in or administered along with the dietary supplement of the invention. Such plant and herbal extracts can be obtained according to well known procedures for the extraction of substances, compounds or agents from plants or herbs. In particular embodiments, the dietary supplement of the present invention includes herbal or plant extracts of broccoli, brussel sprouts, cabbage, carrot, cauliflower, garlic, kale, onion, papaya, pineapple, tomato, asparagus, mushroom, parsnip, radish, and turnip. When a plant or herbal extract is included in the dietary supplement of the invention, the ratio of total extract (dry solids weight basis) to total glyconutrient can range from about 0.001-75/99.999-25 to about 10-90/90-10 on a weight percent basis. Many different types of vitamins and minerals can be included in the dietary supplement of the invention. While a few vitamins and minerals of synthetic origin do possess nutritional value, particular embodiments of the dietary supplement herein contain nutritionally effective amounts of non-toxic vitamins and minerals obtained predominantly from natural sources. PROFILE™ is the tradename of a vitamin and mineral supplement used in the nutritional studies exemplified herein. This product, which can be obtained from MANNATECH™ (Coppell, Tex.), contains nutritionally effective amounts of the following vitamins and minerals: a) vitamins comprising A, B1, B12, B2, B6, beta carotene, bioflavanoids, biotin, C, choline, D, E, folic acid, inositol, K, niacinamide, para-aminobenzoic acid, and pantothenic acid; and b) minerals comprising boron, calcium, copper, GTF chromium, iodine, iron, magnesium, manganese, molybdenum, potassium, selenium, silicon, vanadium, and zinc. These vitamins and minerals may be provided in nutritionally acceptable non-toxic forms. By “nutritionally effective amount” is meant that amount which will provide a beneficial nutritional effect or response in a mammal. For example, as nutritional response to vitamin- and mineral-containing dietary supplements varies from mammal to mammal, it should be understood that nutritionally effective amounts of said vitamins and minerals will vary, respectively. Thus, while one mammal may require a particular profile of vitamins and minerals present in defined amounts, another mammal may require the same particular profile of vitamins and minerals present in different defined amounts. Other compounds, agents and nutrients can also be included in the dietary supplement of the invention, such as, for example, cellulose, calcium carbonate, kola nut, kola nut extract, country mallow, Atlantic kelp, cayenne pepper, silica, stearic acid, amino acids, glycine, lysine, glutamic acid, arginine, calcium carbonate, orchic substances, boron citrate, chromium picolinate, essential fibers, essential oils, essential botanicals, essential enteric ecology and flora growth promoters, essential fatty acids, live probiotic flora, proteins and enzymes. The dietary supplement of the invention has been prepared and administered to mammals in powdered, reconstitutable powder, liquid-solid suspension, liquid, capsule, tablet, caplet, lotion and cream dosage forms. It should be readily obvious to one of ordinary skill in the science of formulations that the present dietary supplement can also be formulated appropriately for irrigation, ophthalmic, otic, rectal, sublingual, transdermal, buccal, vaginal, or dermal administration. Thus, other dosage forms such as chewable candy bar, concentrate, drops, elixir, emulsion, film, gel, granule, chewing gum, jelly, oil, paste, pastille, pellet, shampoo, rinse, soap, sponge, suppository, swab, syrup, chewable gelatin form, or chewable tablet can be used. Due to varying diets among people, the dietary supplement of the invention can be administered in a wide range of dosages and formulated in a wide range of dosage unit strengths. For example, for those people who are missing from their diet nine of the eleven essential saccharides, a dietary supplement containing those nine saccharides in nutritionally effective amounts can be formulated. As well, for those people whose bioabsorption of essential saccharides is extremely efficient, a dietary supplement formulation containing reduced amounts of essential saccharides can be prepared. It should be noted that the dosage of the dietary supplement can also vary according to a particular ailment or disorder that a mammal is suffering from when taking the supplement. For example, a person suffering from chronic fatigue syndrome, or fibromyalgia, will generally require a dose different than an alcoholic who is trying to discontinue alcohol consumption in order to obtain a nutritional benefit. An appropriate dose of the dietary supplement can be readily determined by monitoring patient response, i.e., general health, to particular doses of the supplement. As well, when another agent such as a phytonutrient, plant extract, herbal extract and/or dioscorea complex is being administered to a mammal along with the present glyconutritional dietary supplement, the appropriate doses of the supplement and each of the agents can be readily determined in a like fashion by monitoring patient response, i.e. general health, to particular doses of each. It is contemplated by the invention that the dietary supplement can be administered simultaneously or sequentially in one or a combination of dosage forms. While it is possible and even likely that the present dietary supplement will provide an immediate overall health benefit, such benefit may take days, weeks or months to materialize. Nonetheless, the present glyconutritional dietary supplement will provide a beneficial nutritional response in a mammal consuming it. It is also contemplated that the dietary supplement of the invention can be administered simultaneously or sequentially along with at least one of a phytonutrient, an herbal extract, a plant extract, and a dioscorea complex. Particular embodiments wherein the dietary supplement is administered simultaneously with at least one of a phytonutrient, an herbal extract, a plant extract, and a dioscorea complex are exemplified in the following examples. For the examples herein, the dietary supplement of the invention was administered as a powder-containing capsule. When the dietary supplement included a phytonutrient, it was administered as a caplet or gelatin form. When the dietary supplement included a dioscorea complex, it was administered as either a capsule or caplet. When the dietary supplement included a phytonutrient, a dioscorea complex and an herbal extract, it was administered as a caplet. According to the capsule or caplet size and ingredients used in a given study exemplified herein, the dietary supplement was administered initially as follows. The indicated doses are based upon #1 sized capsules and 1000-1200 mg caplets. SUPPLEMENT DOSAGE Glyco-1 2 capsules, 4x/day Phyto-1 1 caplet, 4x/day Glyco-1 with dioscorea complex 1 caplet, 4x/day PROFILE ™ 1 tablet, 3x/day As the exemplified studies proceeded, the doses of the supplements were modified according to patient response to a prior dosing regimen. For example, if a patient's overall health was not improving at the initial dose, the respective dose for one or more of the supplements was modified. It should be noted that the actual doses ultimately given to each patient in a study varied greatly from patient to patient as nutritional response varied. Generally, the dietary supplement and each of the other supplements was administered in the range of about 1 to about 12 capsules (or caplets or tablets) per day. It is well documented that biochemical individuality exists among mammals and results in a very wide range of drug or food required to obtain a desirable health promoting effect. (Williams, R.; in Nutrition Against Disease, 1971). The amount of the above nutraceuticals typically utilized initially as a dietary supplement is indicated for conditions of compromised health. Energy level, stiffness, pain, discomfort, restful sleep, recovery from fatigue, and emotional status are used as nutritional benefit markers in determining a mammal's nutritional response to the dietary supplement and in determining whether or not an increase in dose is warranted. A reduction of health complaints or a reduction or elimination of the above parameters is used as a guide for the reduction of glyconutrient intake. Complicating factors in regard to the amount of glyconutrients required for a benefit include the differing quantitative needs that individual have for nutrients, the differences being due to genetics, biochemical balance, disease state, altered physiology, prior and current general nutrition, individual choice and the nutrient content of food eaten by individuals. A desirable response or improvement in health is obtained when the missing nutrient or nutrients is/are adequately supplied by the present dietary supplement. The human body defends, repairs, regenerates, regulates, and heals itself through gene-control and nutrition provides the resources to accomplish these tasks. The inventive dietary supplement herein contain glyconutrients no longer commonly found in the urban/suburban food chain and thus supply a more optimal source of known and yet to be identified nutrients necessary for optimal biochemistry and physiology. EXAMPLE 1 A suitable composition for a product according to the present invention is as follows: tragacanth gum (100 kg), a source of galacturonic acid, galactose, fucose, xylose, arabinose and rhamnose is charged into a stainless steel ribbon blender and guar gum (10 kg), a source of mannose and galactose, is charged into the stainless steel ribbon blender. The mixture of tragacanth gum and guar gum is mixed for five (5) minutes. Then 250 grams of Aerosil 380™ (silica gel) is added to the mixture as a flowing agent and 200 kilograms of rice flour, a source of glucose, is added as a gluten-free filler. The mixture is then agitated for fifteen (15) minutes. Finally, 100 grams of calcium stearate is added to the mixture as a lubricant and the mixture is agitated for an additional three (3) minutes to generate a bulk powder. The powder is then encapsulated into size 1 gelatin capsules at a fill weight of 250 mg using a Model 8 (Elanco) capsule filling machine. EXAMPLE 2 Another suitable composition for a product according to the present invention is as follows: 25 kilograms each of galactose, glucose, mannose, N-acetylneuraminic acid, fucose, N-acetylgalactosamine, N-acetylglucosamine, and xylose available from Florida Food Products as well as Aldrich Chemical Company and Sigma Chemical is charged into a stainless steel ribbon blender and mixed for five (5) minutes. Then 250 grams of Aerosil 380™ (silica gel) is added to the mixture as a flowing agent and 200 kilograms of rice flour, a source of glucose, is added as a gluten-free filler. The mixture is then agitated for fifteen (15) minutes. Finally, 100 grams of calcium stearate is added to the mixture as a lubricant and the mixture is agitated for an additional three (3) minutes to generate a bulk powder. The powder is then encapsulated into size #1 gelatin capsules at a fill weight of 250 mg using a Model 8 (Elanco) capsule filling machine. EXAMPLE 3 Another suitable composition for a bulk product according to the present invention is as follows. This formulation can be prepared according to Example 2. The weight percentages indicated are based upon the final weight of the composition. Percent Approximate by Weight Ingredient Density 20 Gum Tragacanth T/3 0.71 g/ml 20 Gum Ghatti No. 1 0.79 g/ml 40 arabinogalactan 0.20 g/ml 20 MANAPOL ® 0.12 g/ml combined ingredients 0.30 g/ml Gum tragacanth T/3 and Gum Ghatti No. 1 are both tree exudates that are available from AEP Colloids of Ballston Spa, New York. Arabinogalactan is obtained from the Larch tree and is available from North American Pharmacal of Norwalk, Conn. MANAPOL® is a freeze-dried aloe vera extract available from Carrington Laboratories (Irving, Tex.). EXAMPLE 4 Standardization Assay The following assay describes a method for standardization of concentrations of sugars covered by this patent. Standards: All carbohydrate standards are available from Aldrich Chemical Company, Milwaukee, Wis. Eluent: Deionized (DI) water having a resistance greater than or equal to about 17 MOhm. Sample preparation: 2 ml of2 N hydrofluoric acid are added to 10 mg of sample to be analyzed in a screw-top, TEFLON lined 10 ml test tube. The sample is then incubated at 120° C. for one hour to hydrolyze into monosaccharides. The excess reagent is removed under a stream of air and the sample resuspended in 1 ml of DI water. HPLC Analysis: AOAC Official Methods of Analysis 977.20 EXAMPLE 5 The dietary supplement formulation of this example was prepared on large scale according to the above examples. This formulation, referred to as Glyco-1, includes the following ingredients in the amounts indicated. The weight percentage is based upon the weight of the final formulation containing all of the ingredients. Ingredient Weight Percent MANAPOL ® 10 (aloe vera extract) gum ghatti 10 gum tragacanth 10 glucosamine 10 corn starch 12 arabinogalactan 48 This composition was formulated into topical and oral preparations as indicated above. EXAMPLE 6 Reduction of Medicine Induced Side Effects in the Treatment of Attention-Deficit Hyperactivity Disorder Manual 4th Ed. (DSM-IV) definitions for ADHD. One group consisted of five children whose parents had not placed them on methylphenidate (NO MED). The other 12 children in the study were receiving one of two different doses of methylphenidate: (a) six children received the normal prescribed dose (MED); and (b) six children received a reduced dose, i.e. below the normal prescribed dose (MED RED). Assessment tools consisted of an ADHD rating scale for the DSM-IV symptoms; 18 items were rated on a scale of 0-3 for severity. Identical scales were constructed for the Oppositional Defiant Disorder (ODD) symptoms and the Conduct Disorder (CD) behaviors listed in DSM-IV. Both parents and teachers completed the above scales at each evaluation. In addition, parents completed a General Health Inventory for their children. After all screening assessments were completed, all subjects had the glyconutritional product Glyco-1 added to their diets (1 capsule per 10 pounds of body weight for the first day and 1 capsule per 20 pounds of body weight for the remainder of the study). At week two, parent and teachers completed another rating series and the MED RED group had their medication reduced by half as per protocol. At week three, phytonutritionals (Phyto- 1; 5 per day) were added to the dietary supplement procedure. The additional rating series were completed at weeks five and six. The results indicated the Glyco-1 did not provide any further improvement in the ADHD symptomatology above that already obtained with the methylphenidate alone. However, a statistically significant reduction in the side-effects caused by the methylphenidate was obtained when Glyco-1 was administered to the subjects; therefore, an improvement in their overall general health was achieved. EXAMPLE 7 Treatment of Alcoholics with Glyco- 1 Glyco-1 capsules used in this study were prepared according to Example 6. The purpose of this study was to evaluate the effectiveness of dietary glyconutritional supplementation on the mood states and craving for alcohol in alcoholics. The study was conducted as follows. Two groups of subjects were recruited from a local alcoholic support group in Little Rock, Ark.: three recovering alcoholics and two practicing alcoholics. Each met the Diagnostic and Statistical Manual 4th Ed. (DSM-IV) criteria for alcohol dependency. In the recovering group, abstinence varied from 2.5 years to six years and 11 months. For both groups, years of alcohol abuse ranged from 15 to 30 years and ages ranged from 33 to 62. Assessment tools consisted of a self-rating scale of craving for alcohol which was scored from 0 to 9 and the Profile of Mood States (POMS). The POMS 65 items were divided into five scales: Cognitive, Depression, Energy, Anger/Temper, and Positive Outlook. These assessments were completed prior to taking glyconutritionals and again at the end of the five-week study. Glyconutritionals were added to each subject's diet: 1 capsule per 10 pounds of body weight for the first day and thereafter 1 capsule per 20 pounds of body weight for the duration of the trial. No other interventions were introduced. Results indicated that the mean initial alcohol craving of the five subjects had decreased in a statistically significant manner. Likewise, the results also indicated statistically significant improvements in the all of the measured mood states. EXAMPLE 8 Treatment of Various Disorders with Glyconutrients The following table summarizes the results obtained when patients were administered Glyco-1 either alone or in combination with one or more of Phyto-1, Glyco-1 with dioscorea and PROFILE™. Each patient was administered an initial dose Glyco-1 and any one or more of the respective supplements in the dosages indicated as follows: SUPPLEMENT DOSAGE Glyco-1 (A) 2 capsules, 4x/day Phyto-1 (B) 1 caplet, 4x/day Glyco-1 with dioscorea complex (C) 1 caplet, 4x/day PROFILE ™ (D) 1 tablet, 3x/day “E” indicates a topical hydrogel formulation comprising glyconutritionals “F” indicates an oral dietary supplement comprising glyconutritionals and herbal extracts. “E” indicates a topical hydrogel formulation comprising glyconutritionals “F” indicates an oral dietary supplement comprising glyconutritionals and herbal extracts. During each study, patient progress and nutritional or overall health response to administration of a given dietary supplement regimen was monitored. For those patients not responding well to initial doses, their dosing regimen was altered and their progress monitored again. It should be noted that in each of the cases, the Glyco-1 at an appropriate dose provided nutritionally effective amounts of the essential saccharide(s) necessary to promote good overall health in a given patient. That is, the glyconutrient-containing dietary supplement of the invention is not intended or professed to cure any of the disorders listed below. Rather, the dietary supplement provides a patient the necessary glyconutrients to permit a patient's own body to heal itself. TABLE 4 Disorders treated by administration of glyconutrients alone or in combination with one or more of phytonutrients, dioscorea complex and vitamins and minerals. NUTRITIONAL PRODUCTS DISORDER ADMINISTERED TREATMENT RESULTS aging process or optimal A, B, C, D decreased body fat; increased health plan muscle mass and bone density; serum biochemistry altered to more healthy values old stable strokes A, B, C restored sensory and muscular control multiple sclerosis A, B, C restored sensory and muscular control amyotrophic lateral A, B, C restored sensory and muscular sclerosis control muscular dystrophy A, B, C restored sensory and muscular control cerebral palsy A, B, C restored sensory and muscular control macular degeneration A, B, C sight restorations seizures A, B, C reduction or elimination of allergies and infections; coordination, learning, memory and appearance improvements Down's Syndrome A, B, C reduction or elimination of allergies & infections; coordination, learning, memory and appearance improvements systemic combined A, B, C antibody and T-cell function immune deficiency restoration syndrome Tay-Sachs A, B, C restoration of lost functions retinitis pigmentosis A, B, C sight restoration color blindness A, B, C can see color Huntington's chorea A, B, C restoration or improvement of lost functions Alzheimer's A, B, C restoration or improvement of lost functions Parkinson's A, B, C restoration or improvement of lost functions inflammatory A, B, C restoration or improvement of polyneuropathy lost functions Closed head traumatic A, B, C restoration or improvement of syndromes lost functions spinal cord injury A, B, C restoration or improvement of lost functions ulcerative colitis A, B, C healed ulcers Crohn's disease A, B, C healed ulcers schizophrenia A, B, C improvements in functions depression A, B, C improvements in functions anxiety reactions A, B, C improvements in functions compulsive disorders A, B, C improvements in functions nervous tics A, B, C improvements in functions restless leg syndrome A, B, C improvements in functions Tourette's syndrome A, B, C improvements in functions autism A, B, C improvements in functions Wegener's granulomatosis A, B, C restoration of tissue Lupus E. A, B healing of lesions Rheumatoid arthritis A, B relief of symptoms thyroiditis A, B normalization of antinuclear antibodies myesthenia gravis A, B normalization of antinuclear antibodies diabetes mellitus A, B normalization of glucose and Hgb AIC; restoration of renal functions; healing of ulcers, elimination of infection; elevated lipids normalize; reduced insulin and glycomeds osteoporosis A, B reduced pain increased bone density alcoholism A reduction in craving cocaine A reduction in craving atherosclerosis A, B reduced total cholesterol, LDL, and triglycerides and increased HDL; improved patency of vessels and arrhythmia idiopathic myocarditis A, B increased ejection function; (presumed viral origin) restoration of heart size; increased Coxsackievirus antibody levels; and reversal of heart failure rheumatoid arthritis A, B elimination of pain, stiffness, fever, and swelling; restoration of scope of motion, strength and endurance degenerative arthritis A, B elimination of pain, stiffness, fever, and swelling; restoration of scope of motion, strength and endurance traumatic arthritis A, B elimination of pain, stiffness, fever, and swelling; restoration of scope of motion, strength and endurance juvenile arthritis A, B elimination of pain, stiffness, fever, and swelling; restoration of scope of motion, strength and endurance asthma A elimination of shortness of breath and wheezing and improvement of pulmonary function allergy-nasal, eyes, hay A elimination of itching, fever swelling, rash discomfort silicon breast implant A, B, C reduction or elimination of symptoms environmental toxin A, B, C reduction or elimination of syndrome symptoms agent orange A, B, C reduction or elimination of symptoms Gulf War syndrome A, B, C reduction or elimination of symptoms Hepatitis B & C A, C, D normalization of liver enzymes and symptoms influenza virus A, C, D prevention or amelioration; improvement of symptoms common cold A, C, D prevention or amelioration; improvement of symptoms AIDS A, C, D elimination of symptoms; m- RNA of HIV-1 is undetected; restored immune function herpes A, C, D elimination of infestations warts A, C, D elimination of infestations human papillovirus A, C, D elimination of infestations otitis media (chronic or A, C, D elimination of symptoms and persistent) need for antibiotics leukemia A, B, C, D correction of altered chromosomes lymphomas A, B, C, D normalization of tissue biopsies sarcomas (astrocytomas) A, B, C, D normalization of tissue biopsies adenocarcinomas such as A, B, C, D elimination of metastasis and breast, prostate, ovarian, shrinkage of mass to gastrointestinal and lung undetectable level profound introversion and A, B, C, D restoration of psychological female impotence interest and physiological sexual function in the elderly pain, ulcers and coldness A, C, E restoration to intact, painless of extremities in diabetes, extremity and microvascular raynauds, frost-bite, circulation snake-bite and atherosclerosis sun damaged skin, age A, C, E lessening of pigmentation, damaged skin, and wrinkles, and lost elasticity radiation damaged skin and restoration of dermis and epidermis athletic performance C, F increased strength and endurance, delayed fatigue, facilitation of recovery in young and aging athletes In summary, this invention pertains to the field of dietary supplements and nutritional support for promotion and maintenance of optimal good health. More specifically, the invention relates to compositions of carbohydrates as dietary supplements that are essential for the production of correctly structured and, therefore, properly functioning glycoproteins. Science has recently shown that glycoproteins play a key role in all cellular communication. Many of the cytokines, i.e. cellular “words,” do not function properly without an attached glycosyl moiety. The body hydrolyzes complex polysaccharides such as plant carbohydrates into various monosugars and restructures them into oligosaccharides that are then used by the body to build the glycoproteins required by cytokines for cellular communication and, thus, for good health. This invention will correct the problem caused by modem diets consisting of highly refined foods, from which many essential ingredients have been eliminated during processing, specifically sugars needed for correctly structured and properly functioning glycoproteins. The above is a detailed description of particular embodiments of the invention. Those of skill in the art should, in light of the present disclosure, appreciate that obvious modifications of the embodiments disclosed herein can be made without departing from the spirit and scope of the invention. All of the embodiments disclosed herein can be made and executed without undue experimentation in light of the present disclosure. The full scope of the invention is set out in the disclosure and equivalent embodiments thereof. The specification should not be construed to unduly narrow the full scope of protection to which the present invention is entitled. As used herein and unless otherwise indicated, the terms “a” and “an” are taken to mean “one”, “at least one” or “one or more”. | <SOH> FIELD OF THE INVENTION <EOH>This invention pertains to the field of dietary supplements and nutritional support for promotion and maintenance of good health. More specifically, the invention relates to compositions of carbohydrates a dietary supplements that are essential for the production of correctly structured and, therefore, properly functioning glycoproteins. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide a dietary supplement which promotes good health by providing to a mammal essential saccharides which are the building blocks of glycoproteins. It has now been demonstrated herein by the present inventors that inclusion of these essential saccharides, as by supplementation of a diet with a dietary supplement containing the same, in the diets of mammals promotes good health. Although not intended to be limited to a particular mechanism of action, these essential saccharides are believed to be absorbed into the mammal's body and utilized in the formation of glycoproteins. By so providing these essential saccharides, the mammal's body does not have to spend energy unnecessarily catabolizing these essential saccharides and can therefore spend its energy providing for other physiological needs such as enhancement of the immune system to ward off, combat and/or ameliorate a wide range of physiological disorders. Thus, the present invention overcomes the disadvantages and drawbacks of the prior art. One aspect of the present invention is directed to the use of various compositions of carbohydrates, i.e., glyconutritionals or glyconutrients, as dietary supplements which supplement a mammal's diet with sugars essential to glycoprotein and/or glycolipid production and thereby promote good health. In one embodiment, the present invention is directed to nutritional supplements including a defined amount of at least one of the eleven carbohydrates that are essential for the production of correctly structured and, therefore, properly functioning glycoproteins and/or glycolipids in a mammal. While some of these eleven sugars are readily available in common food sources, others are quite rare. Accordingly, a first embodiment of the invention provides a dietary supplement for providing nutritional product saccharides which are essential components of glycoproteins in a mammal, said dietary supplement comprising a nutritionally effective amount of at least one saccharide, in monomeric, oligomeric or polymeric and derivatized or underivatized form, selected from the group consisting of: galactose, glucose, mannose, N-acetylneuraminic acid, fucose, N-acetylgalactosamine, N-acetylglucosamine, xylose, arabinose, glucuronic acid, galacturonic acid, iduronic acid, arabinogalactan, acetylated mannose, glucosamine and galactosamine. In other embodiments of the invention, the dietary supplement comprises nutritionally effective amounts of at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten or at least eleven saccharides, in monomeric, oligomeric or polymeric and derivatized or underivatized forms selected from the above listed group. Since some of these saccharides have ionizable groups, the invention contemplates all known non-toxic salt forms thereof. The monomeric, oligomeric or polymeric and derivatized or underivatized forms of these saccharides can be obtained from a wide variety of sources, such as for example, gum tragacanth, guar gum, grain flour, rice flour, sugar cane, beet sugar, potato, milk, agar, algin, locust bean gum, psyllium, karaya gum, seed gums, Larch tree extract, aloe vera extract, gum ghatti, starch, cellulose, degraded cellulose, fructose, high fructose corn syrup, pectin, chitin, acacia, gum arabic, alginic acid, carrageenan, dextran, xanthan gum, chondroitin sulfate, sucrose, acetylated polymannose, maltose, glucan, lentinan, mannan, levan, hemi-cellulose, inulin, fructan, and lactose. Other embodiments of the invention can comprise phytochemicals or phytonutritionals derived from ripened and freeze-dried fruits and vegetables, dioscorea complex, herbal extracts, herbal body-toning agents, beta sitosterol, melatonin, soy lecithin, vitamins, or minerals. In another embodiment of the present invention, the compositions include predigested forms of at least one of the eleven essential carbohydrates. This can include one or all of the following: 1) physical digestion such as shearing or treatment with ultrasound, 2) chemical digestion such as enzymatic digestion, and acid or base hydrolysis, and 3) biological digestion with microbes such as bacteria, fungi or molds. In another aspect, the present invention is a dietary supplement for the modification of behavior in alcohol dependent mammals comprising nutritionally effective amounts of the natural and/or synthetic monomeric, oligomeric and/or polymeric forms of acetylated mannose, gum ghatti, gum tragacanth, glucosamine, corn starch and arabinogalactan. In a particular embodiment, the dietary supplement will reduce the craving for alcohol in an alcohol dependent mammal being administered the supplement. In another particular embodiment, the dietary supplement will improve the overall well being of the alcohol dependent mammal by reducing at least one of depression and anger or increasing at least one of cognition, energy and positive outlook. In yet another aspect, the present invention is a dietary supplement for the reduction of undesired side-effects in mammals receiving biologically effective agents that cause said side-effects, said dietary supplement comprising nutritionally effective amounts of the natural and/or synthetic monomeric, oligomeric and/or polymeric forms of acetylated mannose, gum ghatti, gum tragacanth, glucosamine, corn starch and arabinogalactan. In a particular embodiment, the dietary supplement will reduce the undesired side-effects of central nervous system drugs. In a more particular embodiment, the dietary supplement will reduce the undesired side-effects of methylphenidate in a mammal suffering from attention-deficit hyperactivity disorder and receiving methylphenidate. detailed-description description="Detailed Description" end="lead"? | 20040706 | 20070410 | 20050113 | 77307.0 | 5 | FLOOD, MICHELE C | COMPOSITIONS OF PLANT CARBOHYDRATES AS DIETARY SUPPLEMENTS | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,885,665 | ACCEPTED | Charged particle beam exposure method, charged particle beam exposure apparatus, and device manufacturing method | In a charged particle beam exposure method of applying/not applying charged particle beams to expose a substrate by deflecting the charged particle beams to move the charged particle beams on a blanking aperture stop, the size of the charged particle beams on the blanking aperture stop is made larger than the size of the blanking aperture stop. | 1. A charged particle beam exposure method of controlling irradiation of a substrate with a charged particle beam to expose the substrate by deflecting the charged particle beam to move the charged particle beam on a blanking aperture stop, wherein a size of the charged particle beam on the blanking aperture stop is made larger than a size of an aperture of the blanking aperture stop. 2. A charged particle beam exposure apparatus, comprising: a charged particle beam source which emits a charged particle beam; a first electron optical system which forms an intermediate image of said charged particle beam source; and a second electron optical system which projects the intermediate image formed by said first electron optical system onto the substrate, said first electron optical system having an electron lens, a deflector which deflects a charged particle beam that passes through the electron lens, and a blanking aperture stop having an aperture which passes a charged particle beam not deflected by the deflector, wherein a size of the charged particle beam on the blanking aperture stop is made larger than a size of an aperture of the blanking aperture stop. 3. The apparatus according to claim 2, wherein said first electron optical system has a plurality of electron lenses, a plurality of deflectors which deflect a plurality of charged particle beams that pass through the plurality of electron lenses, respectively, and a blanking aperture stop having apertures which pass charged particle beams not deflected by said deflectors, and a size of each charged particle beam on the blanking aperture stop is made larger than a size of an aperture of the blanking aperture stop. 4. A charged particle beam exposure apparatus, comprising: a charged particle beam source which emits a charged particle beam; a deflector which deflects the charged particle beam; and a blanking aperture stop having an aperture which passes a charged particle beam not deflected by said deflector, and wherein a cross-sectional area of the charged particle beam on said blanking aperture stop is made larger than an area of the aperture of said blanking aperture stop. 5. A device manufacturing method comprising: an exposure step of exposing a substrate to a pattern using a charged particle beam exposure apparatus as defined in claim 2; and a development step of developing the substrate which has been exposed to the pattern in the exposure step. 6. A device manufacturing method comprising: an exposure step of exposing a substrate to a pattern using a charged particle beam exposure apparatus as defined in claim 4; and a development step of developing the substrate which has been exposed to the pattern in the exposure step. | FIELD OF THE INVENTION The present invention relates to a charged particle beam exposure method, a charged particle beam exposure apparatus, and a device manufacturing method, which expose a substrate such as a wafer to a fine pattern with a charged particle beam. The charged particle beam exposure method, charged particle beam exposure apparatus, and device manufacturing method of this type are mainly used to expose to light a device bearing a fine pattern of, for example, a semiconductor integrated circuit in a charged particle beam exposure apparatus such as an electron beam exposure apparatus, ion beam exposure apparatus, or the like. BACKGROUND OF THE INVENTION As an exposure apparatus which exposes a substrate to a fine pattern of, for example, a semiconductor chip such as an IC or LSI, liquid crystal panel, CCD, thin-film magnetic head, micromachine, or the like, there is known a charged particle beam exposure apparatus which draws a pattern using an electron beam or ion beam, such as an electron beam exposure apparatus (see Japanese Patent Laid-Open No. 9-245708), ion beam exposure apparatus, or the like. FIG. 5A shows a conventional raster scanning electron beam exposure apparatus. In FIG. 5A, reference symbol S denotes an electron source which emits an electron beam, and B, a blanker. An electron beam from the electron source S forms an image of the electron source S at the same position as the blanker B through an electron lens L1. The image of the electron source is reduced and projected onto a wafer W through a reduction electron optical system comprising electron lenses L2 and L3. The blanker B is an electrostatic deflector which is located at the same position as the image of the electron source S formed through the electron lens L1. The blanker B controls whether to irradiate the wafer with an electron beam. More specifically, when the wafer is not to be exposed to an electron beam, the blanker B deflects the electron beam, and a blanking aperture stop BA located on the pupil of the reduction electron optical system cuts off the deflected electron beam (i.e., an electron beam EBoff). On the other hand, when the wafer is to be exposed to an electron beam, an electron beam EBon having passed through the blanking aperture stop BA is controlled by an electrostatic deflector DEF to scan the wafer W. A method of drawing on the wafer by raster scanning will be described with reference to FIG. 5B. For example, to draw a pattern of a character “A”, a drawing region is divided into a plurality of pixels. While the deflector DEF moves an electron beam to perform scanning in the X direction, the blanker B performs control such that each pixel constituting part of the pattern (gray portion) is irradiated with the electron beam and each of the remaining pixels shields the electron beam. When the scanning in the X direction ends, the electron beam is stepped in the Y direction, and the scanning in the X direction restarts. Electron beam irradiation is controlled during the scanning, thereby drawing the pattern. As shown in FIG. 6A, when the blanker B switches the beam state from an electron beam OFF state to an electron beam ON state to irradiate the wafer W with an electron beam, the electron beam is made to move on the blanking aperture stop BA by the blanker B and passes through the aperture of the blanking aperture stop BA. In the conventional apparatus, the diameter of electron beam is smaller than the aperture diameter of the blanking aperture stop, and a driver which drives the blanker B serving as the electrostatic deflector may cause an overshoot. For this reason, even in the beam ON state, the center of the electron beam fluctuates about the center of the aperture (d≠0) until it stabilizes at the center of the aperture, as shown in FIG. 6B. An image of an electron beam which comes incident on the wafer at a position shifted from the center of the aperture does not have a desired axisymmetric intensity distribution as shown in FIG. 6D but has a distorted intensity distribution as shown in FIG. 6C. Accordingly, it is difficult to form a desired fine pattern on the wafer. SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned conventional drawback, and has as its object to provide a charged particle beam exposure method, charged particle beam exposure apparatus, and device manufacturing method which can perform exposure to a desired pattern. According to the first aspect of the present invention, there is provided a charged particle beam exposure method of controlling irradiation of a substrate with a charged particle beam to expose the substrate by deflecting the charged particle beam to move the charged particle beam on a blanking aperture stop, wherein a size of the charged particle beam on the blanking aperture stop is made larger than a size of an aperture of the blanking aperture stop. According to the second aspect of the present invention, there is provided a charged particle beam exposure apparatus, comprising a charged particle beam source which emits a charged particle beam, a first electron optical system which forms an intermediate image of the charged particle beam source, and a second electron optical system which projects the intermediate image formed by the first electron optical system onto the substrate, the first electron optical system having an electron lens, a deflector which deflects a charged particle beam that passes through the electron lens, and a blanking aperture stop having an aperture which passes a charged particle beam not deflected by the deflector, wherein a size of the charged particle beam on the blanking aperture stop is made larger than a size of an aperture of the blanking aperture stop. According to the third aspect of the present invention, there is provided a charged particle beam exposure apparatus, comprising a charged particle beam source which emits a charged particle beam, a deflector which deflects the charged particle beam, and a blanking aperture stop having an aperture which passes a charged particle beam not deflected by the deflector, wherein a cross-sectional area of the charged particle beam on the blanking aperture stop is made larger than an area of the aperture of the blanking aperture stop. According to the fourth aspect of the present invention, there is provided a device manufacturing method comprising an exposure step of exposing a substrate to a pattern using the above-mentioned charged particle beam exposure apparatus, and a development step of developing the substrate which has been exposed to the pattern in the exposure step. Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. FIG. 1 is a view schematically showing the main part of an electron exposure apparatus according to an embodiment of the present invention; FIG. 2 is a view for explaining electron beams and a blanking aperture stop according to this embodiment; FIG. 3 is a diagram for explaining a system according to this embodiment; FIG. 4 is a view for explaining an exposure method according to this embodiment; FIGS. 5A and 5B are views for explaining a conventional raster scanning electron beam exposure apparatus; FIGS. 6A to 6D are charts for explaining a pixel intensity distribution obtained by conventional raster scanning; FIG. 7 is a flowchart for explaining the flow of a device manufacturing process; and FIG. 8 is a flowchart for explaining the wafer process in FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As an example of a charged particle beam exposure apparatus according to a preferred embodiment of the present invention, this embodiment will illustrate an electron beam exposure apparatus. Note that this embodiment can be applied to not only exposure apparatuses using electron beams but also ones using ion beams. <Explanation of Components of Electron Beam Exposure Apparatus> FIG. 1 is a view schematically showing the main part of an electron beam exposure apparatus according to an embodiment of the present invention. In FIG. 1, an electron beam generated by an electron gun (not shown) forms a crossover image 1 (to be referred to as an electron source 1 hereinafter). An electron beam emitted from the electron source 1 passes through a beam shaping optical system 2 and forms an image SI of the electron source 1. At this time, a first stigmator 3 serving as a magnetic octupole stigmator can cause astigmatism in the image SI. This astigmatism can correct any astigmatism in an electron beam image projected onto a wafer 9 (to be described later). The electron beam from the image SI becomes almost parallel through a collimator lens 4. The almost parallel electron beam comes incident on an aperture array 5 having a plurality of apertures. The aperture array 5 divides the electron beam into a plurality of electron beams which correspond to the plurality of apertures in a one-to-one relationship. The plurality of electron beams derived from the aperture array 5 form intermediate images of the image SI through an electrostatic lens array 6 having a plurality of electrostatic lenses. A blanker array 7 which has a plurality of blankers serving as electrostatic deflectors is arranged on the plane of the intermediate images. A reduction electron optical system 8 comprising two symmetric magnetic doublet lenses 81 and 82 is provided downstream of the intermediate image plane. The plurality of intermediate images are projected onto the wafer 9. At this time, electron beams deflected by the blanker array 7 are shielded by a blanking aperture stop BA and thus do not come incident on the wafer 9. On the other hand, electron beams not deflected by the blanker array 7 are not shielded by the blanking aperture stop BA and thus come incident on the wafer 9. That is, the blanker array 7 individually controls to apply/not to apply (performs on-off control for) the plurality of electron beams derived from the aperture array 5 to the wafer 9. Electron beams having passed through the apertures of the aperture array 5 form an image on the blanking aperture stop BA. In the electron optical system of the electron beam exposure apparatus according to this embodiment, the image of the apertures of the aperture array 5, formed on the blanking aperture stop BA, is made larger than the aperture of the blanking aperture stop BA. That is, as shown in FIG. 2, the size of the electron beams on the blanking aperture stop BA (2×Rb) is made larger than that of the aperture of the blanking aperture stop BA (2×Ra). It is more preferable to make the size of the electron beams on the blanking aperture stop BA larger than the sum of the size of the aperture of the blanking aperture stop BA and a variation δ (see FIG. 6B) on the blanking aperture stop BA of the electron beams. The cross-sectional area on the blanking aperture stop BA of the electron beams may be made larger than the area of the aperture of the blanking aperture stop BA. In this case, even if the center of the electron beams is not located at the center of the aperture of the blanking aperture stop BA, the center of the electron beams having passed through the blanking aperture stop BA is located at the center of the aperture of the blanking aperture stop BA. Thus, a desired image is projected onto the wafer 9, and the wafer 9 is exposed to a desired pattern. According to this embodiment, any of the plurality of electron beams derived from the aperture array 5 passes through the single blanking aperture stop BA and comes incident on the wafer 9. Variations in size between the plurality of apertures formed in the aperture array 5 can be smoothed, and variations in incident angles generated when the electron beams come incident on the blanker array 7 can be smoothed. Accordingly, a desired image is projected onto the wafer 9, and the wafer 9 is exposed to a desired pattern. A deflector 10 which simultaneously displaces a plurality of electron beams in the X and Y directions to desired positions, a second stigmator 11 serving as an electrostatic octupole stigmator which simultaneously adjusts any astigmatism of the plurality of electron beams, and a focus coil 12 which simultaneously adjusts the focuses of the plurality of electron beams are arranged in the lower doublet lens 82. Reference numeral 13 denotes an X-Y stage 13 on which the wafer 9 is mounted and which can move in the X and Y directions perpendicular to the optical axis. An electrostatic chuck 15 for chucking the wafer 9 and a semiconductor detector 14 for measuring the shape of electron beams which has a single knife edge extending in the X and Y directions on the electron beam incident side are arranged on the stage. The X-direction shape of electron beams can be measured using a change in output of the semiconductor detector 14 when the electron beams are moved to perform scanning in the Y direction with respect to the single knife edge extending in the X direction. The Y-direction shape of the electron beams can be measured using a change in output of the semiconductor detector 14 when the electron beams are moved to perform scanning in the X direction with respect to the single knife edge extending in the Y direction. Note that this embodiment uses the second stigmator 11 to correct any astigmatism which changes upon deflecting electron beams and uses the first stigmator 3 to correct any astigmatism which does not change upon deflecting the electron beams such as one caused by lens decentering in apparatus assembly. The first stigmator 3 may be arranged at any position on the optical axis but is preferably arranged between the electron source 1 and the aperture array 5. <Explanation of System Configuration and Exposure Method> FIG. 3 is a diagram of the configuration of a system according to this embodiment. A first stigmator control circuit 21 is a control circuit which controls astigmatism of the electron source image SI by adjusting a difference in focal length in a direction perpendicular to the first stigmator 3. A blanker array control circuit 22 is a control circuit which individually controls the plurality of blankers of the blanker array 7. A deflector control circuit 23 is a control circuit which controls the deflector 10. A second stigmator control circuit 24 is a control circuit which controls astigmatism of the reduction electron optical system 8 by adjusting a difference in focal length in a direction perpendicular to the second stigmator 11. An electron beam shape detection circuit 25 is a detection circuit which processes signals from the semiconductor detector 14. A focus control circuit 26 is a control circuit which controls the focal position of the reduction electron optical system 8 by adjusting the focal length of the focus coil 12. A stage drive control circuit 27 is a control circuit which controls to drive the X-Y stage 13 in cooperation with a laser interferometer (not shown) which detects the position of the X-Y stage 13. A main control system 28 controls the above-mentioned plurality of control circuits and manages the entire electron beam exposure apparatus. FIG. 4 is a view for explaining an exposure method according to this embodiment. Drawing operation of the apparatus shown in FIGS. 1 and 3 will be described with reference to FIG. 4. The main control system 28 instructs the deflector control circuit 23 on the basis of exposure control data to make the deflector 10 deflect a plurality of electron beams. The main control system 28 also instructs the blanker array control circuit 22 to perform on-off control for the blankers of the blanker array 7 in accordance with whether each pixel on the wafer 9 should be exposed. Each electron beam performs raster scanning exposure for a corresponding element exposure region (EF) on the wafer 9, as shown in FIG. 4. Electron beam element exposure regions (EF) are two-dimensionally juxtaposed to each other, and a subfield (SF) comprising a plurality of element exposure regions (EF) to be simultaneously exposed is exposed. In one example, the number of electron beams derived from the aperture array 5 is 32×32=1,024. Each electron beam draws an element exposure region (EF) of about 2 μm square. The diameter of one electron beam on the wafer is about 60 nm. 1,024 (=32×32) element exposure regions constitute one subfield (SF). The size of one subfield (SF) is about 64 μm square. After the main control system 28 exposes one subfield (SF1), it instructs the deflector control circuit 23 to make the deflector 10 deflect a plurality of electron beams in order to exposure the next subfield (SF2). At this time, a change in subfield due to the deflection causes a change in aberration generated when each electron beam is reduced and projected through the reduction electron optical system 8. The second stigmator control circuit 24 performs correction in accordance with instructions from the main control system 28 such that the astigmatism becomes constant. After a group of about-2-mm-square subfields each comprising a group of 1,024 (=32×32) about-64-μm-square subfields are exposed, the X-Y stage is moved by about 2 mm to exposure the next subfield group. Although not shown, the deflector 10 comprises a main deflector used when the deflection width is large, and a sub-deflector used when the deflection width is small. The main deflector is a magnetic deflector while the sub-deflector is an electrostatic deflector. The electrostatic sub-deflector scans the element exposure regions while the magnetic main deflector switches between subfields. (Device Production Method) An example of a device production method using the above-mentioned electron beam exposure apparatus will be explained. FIG. 7 shows the manufacturing flow of a microdevice (e.g., a semiconductor chip such as an IC or LSI, liquid crystal panel, CCD, thin-film magnetic head, micromachine, or the like). In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (exposure control data creation), exposure control data for an exposure apparatus is created based on the designed circuit pattern. In step 3 (wafer manufacture), a wafer is manufactured by using a material such as silicon. In step 4 (wafer process) called a preprocess, an actual circuit is formed on the wafer by lithography using the prepared wafer and the exposure apparatus, into which the exposure control data is input. Step 5 (assembly) called a postprocess is the step of forming a semiconductor chip by using the wafer formed in step 4, and includes an assembly process (dicing and bonding) and packaging process (chip encapsulation). In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and durability test of the semiconductor device manufactured in step 5. After these steps, the semiconductor device is completed and shipped (step 7). FIG. 8 shows the detailed flow of the above-mentioned wafer process. In step 11 (oxidation), the wafer surface is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted in the wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern is transferred onto the wafer coated with the photosensitive agent using the above-mentioned exposure apparatus. In step 17 (development), the exposed wafer is developed. In step 18 (etching), the resist is etched except for the developed resist image. In step 19 (resist removal), an unnecessary resist after etching is removed. These steps are repeated to form multiple circuit patterns on the wafer. With the manufacturing method according to this embodiment, highly integrated semiconductor devices which have been difficult to manufacture by a conventional method can be manufactured at low cost. The above-mentioned embodiment has explained a case wherein the present invention is applied to a multi-electron beam exposure apparatus which performs drawing with a plurality of electron beams. The present invention may be applied to a case wherein a single electron beam is used to perform drawing. In this case, an image of the electron beam with stable intensity distribution can be projected onto the wafer 9 without being much influenced by a variation in center position of electron beams which come into the aperture of a blanking aperture stop in an electron beam on state. Also, the wafer 9 can be exposed to a desired fine pattern. As has been described above, according to the present invention, there can be provided a charged particle beam exposure method and charged particle beam drawing apparatus which apply/do not apply charged particle beams to expose a substrate by deflecting the charged particle beams to move them on a blanking aperture stop, wherein exposure to a desired pattern can be performed even when electron beams are not located at the center of the aperture of the blanking aperture stop. With this method, devices with higher yields can be manufactured. As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>As an exposure apparatus which exposes a substrate to a fine pattern of, for example, a semiconductor chip such as an IC or LSI, liquid crystal panel, CCD, thin-film magnetic head, micromachine, or the like, there is known a charged particle beam exposure apparatus which draws a pattern using an electron beam or ion beam, such as an electron beam exposure apparatus (see Japanese Patent Laid-Open No. 9-245708), ion beam exposure apparatus, or the like. FIG. 5A shows a conventional raster scanning electron beam exposure apparatus. In FIG. 5A , reference symbol S denotes an electron source which emits an electron beam, and B, a blanker. An electron beam from the electron source S forms an image of the electron source S at the same position as the blanker B through an electron lens L 1 . The image of the electron source is reduced and projected onto a wafer W through a reduction electron optical system comprising electron lenses L 2 and L 3 . The blanker B is an electrostatic deflector which is located at the same position as the image of the electron source S formed through the electron lens L 1 . The blanker B controls whether to irradiate the wafer with an electron beam. More specifically, when the wafer is not to be exposed to an electron beam, the blanker B deflects the electron beam, and a blanking aperture stop BA located on the pupil of the reduction electron optical system cuts off the deflected electron beam (i.e., an electron beam EB off ). On the other hand, when the wafer is to be exposed to an electron beam, an electron beam EB on having passed through the blanking aperture stop BA is controlled by an electrostatic deflector DEF to scan the wafer W. A method of drawing on the wafer by raster scanning will be described with reference to FIG. 5B . For example, to draw a pattern of a character “A”, a drawing region is divided into a plurality of pixels. While the deflector DEF moves an electron beam to perform scanning in the X direction, the blanker B performs control such that each pixel constituting part of the pattern (gray portion) is irradiated with the electron beam and each of the remaining pixels shields the electron beam. When the scanning in the X direction ends, the electron beam is stepped in the Y direction, and the scanning in the X direction restarts. Electron beam irradiation is controlled during the scanning, thereby drawing the pattern. As shown in FIG. 6A , when the blanker B switches the beam state from an electron beam OFF state to an electron beam ON state to irradiate the wafer W with an electron beam, the electron beam is made to move on the blanking aperture stop BA by the blanker B and passes through the aperture of the blanking aperture stop BA. In the conventional apparatus, the diameter of electron beam is smaller than the aperture diameter of the blanking aperture stop, and a driver which drives the blanker B serving as the electrostatic deflector may cause an overshoot. For this reason, even in the beam ON state, the center of the electron beam fluctuates about the center of the aperture (d≠0) until it stabilizes at the center of the aperture, as shown in FIG. 6B . An image of an electron beam which comes incident on the wafer at a position shifted from the center of the aperture does not have a desired axisymmetric intensity distribution as shown in FIG. 6D but has a distorted intensity distribution as shown in FIG. 6C . Accordingly, it is difficult to form a desired fine pattern on the wafer. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been made in consideration of the above-mentioned conventional drawback, and has as its object to provide a charged particle beam exposure method, charged particle beam exposure apparatus, and device manufacturing method which can perform exposure to a desired pattern. According to the first aspect of the present invention, there is provided a charged particle beam exposure method of controlling irradiation of a substrate with a charged particle beam to expose the substrate by deflecting the charged particle beam to move the charged particle beam on a blanking aperture stop, wherein a size of the charged particle beam on the blanking aperture stop is made larger than a size of an aperture of the blanking aperture stop. According to the second aspect of the present invention, there is provided a charged particle beam exposure apparatus, comprising a charged particle beam source which emits a charged particle beam, a first electron optical system which forms an intermediate image of the charged particle beam source, and a second electron optical system which projects the intermediate image formed by the first electron optical system onto the substrate, the first electron optical system having an electron lens, a deflector which deflects a charged particle beam that passes through the electron lens, and a blanking aperture stop having an aperture which passes a charged particle beam not deflected by the deflector, wherein a size of the charged particle beam on the blanking aperture stop is made larger than a size of an aperture of the blanking aperture stop. According to the third aspect of the present invention, there is provided a charged particle beam exposure apparatus, comprising a charged particle beam source which emits a charged particle beam, a deflector which deflects the charged particle beam, and a blanking aperture stop having an aperture which passes a charged particle beam not deflected by the deflector, wherein a cross-sectional area of the charged particle beam on the blanking aperture stop is made larger than an area of the aperture of the blanking aperture stop. According to the fourth aspect of the present invention, there is provided a device manufacturing method comprising an exposure step of exposing a substrate to a pattern using the above-mentioned charged particle beam exposure apparatus, and a development step of developing the substrate which has been exposed to the pattern in the exposure step. Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. | 20040708 | 20060523 | 20050113 | 78306.0 | 0 | NGUYEN, KIET TUAN | CHARGED PARTICLE BEAM EXPOSURE METHOD, CHARGED PARTICLE BEAM EXPOSURE APPARATUS, AND DEVICE MANUFACTURING METHOD | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,885,713 | ACCEPTED | Method of manufacturing electronic device and method of manufacturing semiconductor device | The invention provides a semiconductor device, which removes troubles occurring when the parasitic capacitance between layered wiring lines with an interlayer insulating film therebetween is reduced, and have a simple structure and high reliability. The electronic device according to the invention can include a semiconductor layer formed on a substrate, a gate insulating layer formed on the semiconductor layer, a gate electrode having a predetermined pattern and formed on the gate insulating layer, an interlayer insulating film formed to cover the gate electrode, a source electrode and a drain electrode formed on the interlayer insulating film. The interlayer insulating film can be mainly made of silicon oxynitride with a nitrogen concentration of atomic percent or higher. | 1. A method of manufacturing an electronic device, including a step of forming a layered structure, comprising the steps of: forming a first conductive layer having a predetermined pattern on a base; forming an insulating layer mainly made of silicon oxynitride and having a nitrogen concentration of 2 atomic percent or higher on the first conductive layer; and forming a second conductive layer on the insulating layer. 2. The method of manufacturing an electronic device according to claim 1, in addition to the layered structure forming step, the method further includes a step of annealing the formed layered structure. 3. The method of manufacturing an electronic device according to claim 2, the annealing including heat-annealing based on heating. 4. The method of manufacturing an electronic device according to claim 2, the annealing being performed in a water vapor atmosphere. 5. The method of manufacturing an electronic device according to claim 2, the annealing lowering the nitrogen concentration of the insulating layer to 0.5 atomic percent or lower. 6. The method of manufacturing an electronic device according to claim 1, the step of forming the first conductive layer further including the steps of: forming a relatively low melting point conductive layer on the base; and forming a first relatively high melting point conductive layer on the low melting point conductive layer. 7. The method of manufacturing an electronic device according to claim 1, the step of forming the first conductive layer further including the steps of: forming a first relatively high melting point conductive layer on the base; forming a relatively low melting point conductive layer on the first high melting point conductive layer; and forming a second relatively high melting point conductive layer on the low melting point conductive layer, and the second relatively high melting point conductive layer having a melting point higher than that of the low melting point conductive layer. 8. The method of manufacturing an electronic device according to claim 6, the low melting point conductive layer including a layer mainly made of aluminum, and the second high melting point conductive layer being a layer mainly made of any one of high purity metal, metal nitride, and metal oxide. 9. The method of manufacturing an electronic device according to claim 1, the insulating layer being formed to be thicker than the first conductive layer during the insulating layer forming step. 10. A method of manufacturing a semiconductor device including a step of forming a layered structure, comprising the steps of: forming a semiconductor layer on a base; forming a gate insulating layer on the semiconductor layer; forming a gate electrode having a predetermined pattern on the gate insulating layer; forming an interlayer insulating layer mainly made of silicon oxynitride and having a nitrogen concentration of 2 atomic percent or higher on the gate electrode; and forming a conductive layer on the interlayer insulating layer. 11. The method of manufacturing a semiconductor device according to claim 10, in addition to the step of forming the layered structure, the method further includes the step of annealing the layered structure. 12. A semiconductor device comprising: a semiconductor layer formed on a base; a gate insulting layer formed on the semiconductor layer; a gate electrode formed on the gate insulating layer; an interlayer insulating layer formed on the gate electrode; and a conductive layer formed on the interlayer insulating layer, at least the interlayer insulating layer at the side of the gate electrode being mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. 13. The semiconductor device according to claim 12, the interlayer insulating layer formed between the gate electrode and the conductive layer being mainly made of silicon oxynitride with a nitrogen concentration of 0.5 atomic percent or lower. | BACKGROUND OF THE INVENTION 1. Field of Invention The present invention relates to a method of manufacturing an electronic device and a method of manufacturing a semiconductor device. 2. Description of Related Art To realize large-scale integration (LSI) of electronic devices, such as semiconductor devices, wiring lines have recently become multi-layered. In electronic devices having such multi-layered wiring lines, upper and lower wiring patterns with an interlayer insulating film disposed therebetween are electrically connected to each other through contact holes formed in the interlayer insulating film. Here, in order to reduce the parasitic capacitance between the wiring lines, there have been proposed various methods of selecting a material having a low dielectric constant for the interlayer insulating film, making the interlayer insulating film thick, etc. Generally, silicon oxide is used as the material for the interlayer insulating film. However, if a silicon oxide film is thickened, film stress becomes larger, thereby causing cracks. Further, if the thick interlayer insulating film is formed on the wiring lines having an acute shape, constrictions (overhangs) are generated in the interlayer insulating film corresponding to the acute shape, so that there arises a problem that the wiring lines formed thereon is likely to short-circuit. Therefore, in order to avoid the influence due to the constrictions generated when the interlayer insulating film is formed on the wiring lines having the acute shape, for example, Japanese Unexamined Patent Application Publication No. 55-145356 discloses technology that phosphate glass is formed on the interlayer insulating film and then the wiring lines are formed on the glass. SUMMARY OF THE INVENTION According to such technology disclosed above, short-circuiting which may be caused in wiring lines due to constrictions formed in the interlayer insulating film can be prevented or suppressed, but the parasitic capacitance between the wiring lines is not reduced. Also, the interlayer insulating film is formed to have a two-layered structure, so that it takes time to manufacture the interlayer insulating film, a stress based on the difference between the coefficients of thermal expansion of the layers is generated, and the film is peeled off. An object of the invention is to provide an electronic device or a semiconductor device or a semiconductor device capable of reducing the parasitic capacitance between layered wiring lines with an interlayer insulating film disposed therebetween. More particularly the invention can provide a method of manufacturing an electronic device and a method of manufacturing a semiconductor, which sweeps away troubles which may occur when the parasitic capacitance is reduced, and have a simple structure and high reliability. In order to solve the above problems, the invention can provide a method of manufacturing an electronic device including a step of forming a layered structure. The step of forming a layered structure can further include the steps of forming a first conductive layer having a predetermined pattern on a base, forming an insulating layer mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher on the first conductive layer, and forming a second conductive layer on the insulating layer. In the present specification, the mainly made of means including a component of the largest content among all components. As a result of study, it has been found that a film stress generated when the insulating layer is thickened can be controlled by the components of the insulating layer. That is, as described above, when a thick insulating layer mainly made of silicon oxynitride (represented by the composition formula: SixOyNz, where x, y and z are natural numbers) with a nitrogen concentration of 2 atomic percent or higher between the first conductive layer and the second conductive layer is formed, it has been found that a film stress generated when the insulating layer is thickened is smaller than that of the conventional insulating layer. Therefore, according to the method of manufacturing an electronic device of the invention, for example, even though a thick insulating layer is formed to reduce the parasitic capacitance between the conductive layers, the film stress can be decreased, thereby preventing or suppressing the generation of cracks in the insulating layer. Also, for example, even though the first conductive layer has an acute shape, the generation of constrictions in the insulating layer corresponding to the acute shape can be reduced and the short-circuiting hardly occurs in the second conductive layer formed on the insulating layer, thereby providing an electronic device with a high reliability. Further, if annealing is performed after a stable insulating layer with few cracks is formed in such a state that the nitrogen concentration is relatively high, the nitrogen concentration of the insulating layer can be decreased. Consequently, the insulating layer can be thickened to reduce the parasitic capacitance between the conductive layers and the parasitic capacitance can also be reduced by the low dielectric constant due to a decrease in the nitrogen concentration of the insulating layer. That is, according to the method of manufacturing an electronic device of the invention, the insulating layer can be thickened without causing troubles occurring in the conventional method of manufacturing an electronic device, and the parasitic capacitance between the conductive layers can be decreased without lowering the reliability because the dielectric constant is lowered in the case where the insulating layer is annealed, thereby improving the reliability of the electronic device to be manufactured. Particularly, the problems such as the generation of cracks in the insulating layer or short-circuiting in the conductive layer due to the thickened insulating layer are completely solved, so that the parasitic capacitance between the conductive layers can be decreased without troubles. Thus, the manufacturing method of the invention can provide an electronic device with a high reliability, in which an insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the conductive layers. In the manufacturing method of the invention, the annealing may include heat annealing based on heating, specifically, the annealing may be performed in a water vapor atmosphere, in an oxygen atmosphere, and in a hydrogen atmosphere. By performing such annealing, the nitrogen concentration of the insulating layer is lowered to 0.5 atomic percent or lower. In other words, according to the manufacturing method of the invention, after an insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed, the annealing is performed under the conditions that the nitrogen concentration of the insulating layer is 0.5 atomic percent or lower. Further, in the manufacturing method of the invention, the first conductive layer forming step may include the steps of forming a relatively low melting point conductive layer on the base, and forming a first relatively high melting point conductive layer on the low melting point conductive layer. In this case, for example, when the first conductive layer is formed to have a predetermined pattern by etching, the low melting point conductive layer is likely to become relatively narrowed by side-etching and the first high melting point conductive layer is likely to have an awning shape. Thus, in the case where a conventional insulating layer made of silicon oxide is formed so as to cover the first conductive layer, the above-mentioned constrictions are more likely to be generated. However, according to the manufacturing method of the present invention, even if the insulating layer is formed on the first conductive layer having such awning shape, a constriction is hardly generated, that is, constrictions are hardly generated because an insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed. Specifically, for example, the low melting point conductive layer may comprise a layer mainly made of aluminum, and the high melting point conductive layer may comprise a layer mainly made of nitride. Besides, for example, the first conductive layer forming step may include the steps of forming a first relatively high melting point conductive layer on the base, forming a relatively low melting point conductive layer on the first high melting point conductive layer, and forming a second relatively high melting point conductive layer on the low melting point conductive layer. The second relatively high melting point conductive layer has a melting point higher than that of the low melting point conductive layer. Moreover, the low melting point conductive layer may include a layer mainly made of aluminum, and the second high melting point conductive layer may include a layer mainly made of any one of high purity metal, metal nitride, and metal oxide. In any case, an awing shape is formed in the first conductive layer etching step, and an insulating layer for covering the first conductive layer includes a layer mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher, thereby preventing or suppressing the generation of the above-mentioned cracks. Further, the insulating layer may be formed to be thicker than the first conductive layer during the insulating layer forming step. In this case, the insulating layer can be thickened to decrease the parasitic capacitance between the conductive layers is decreased. On the other hand, constrictions are likely to be generated as compared to the case that an insulating layer is thinner than the first conductive layer. However, the generation of constrictions is suitably prevented or suppressed because an insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Moreover, the following structure obtained as an intermediate product in the manufacturing method of the invention may also be suitably used as an electronic device. That is, the invention can provide an electronic device having a first conductive layer having a predetermined pattern, an insulated layer formed so as to cover the first conductive layer, and a second conductive layer formed on the insulating layer. The insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. As described above, in the electronic device comprising an insulating layer mainly made of silicon oxynitride (represented by the composition formula: SixOyNz, where x, y and z are natural numbers) with a nitrogen concentration of 2 atomic percent or higher between the first and second conductive layers, a film stress generated when the insulating layer is thickened is relatively lower than that of the conventional electronic device. Hence, according to the above-mentioned electronic device, for example, even when the insulating layer is thickened to decrease the parasitic capacitance between the conductive layers, the film stress can be reduced, thereby preventing or suppressing the generation of cracks in the insulating layer. Further, for example, even when the first conductive layer has an acute shape, the generation of constrictions in the insulating layer corresponding to the acute shape is decreased, and the short-circuiting hardly occurs in the second conductive layer formed on the insulating layer. In other words, according to the above-mentioned electronic device, since an insulating layer can be thickened without causing troubles occurring in the conventional electronic device, the parasitic capacitance between the conductive layers can be decreased, thereby farther enhancing the reliability of the electronic device. Particularly, the problems such as the generation of cracks in the insulating layer due to the thickened layer and the short-circuiting in the conductive layer due to the thickened layer are completely solved, so that the parasitic capacitance between the conductive layers can be decreased without troubles. Therefore, the invention can provide an electronic device with a high reliability, in which an insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the conductive layers. Moreover, in the above electronic device, the insulating layer may have a refractive index of 1.5 or higher (measured wavelength of 632 nm). Further, in the above electronic device, the first conductive layer may have a layered structure having a low melting point conductive layer, and a first high melting point conductive layer. The first high melting point conductive layer may be arranged on the side of the insulating layer. In this case, for example, when the first conductive layer is formed to have a predetermined pattern by etching, the low melting point conductive layer is likely to become relatively narrowed by side-etching and the first high melting point conductive layer is likely to have an awning shape. Therefore, in the case where a conventional insulating layer made of silicon oxide is formed so as to cover the first conductive layer, the above-mentioned constrictions are more likely to be formed. However, in the structure of the above electronic device, even if the insulating layer is formed on the first conductive layer having such an awning shape, constrictions are hardly generated, that is, the parasitic capacitance between the conductive layers can be decreased. Thus, the insulating layer can be thickened without problems. As a specific structure of the above first conductive layer, for example, the low melting point conductive layer may have a layer mainly made of aluminum, and the first high melting point conductive layer is made of any one of high purity metal, metal nitride, and metal oxide. Further, for example, the high melting point conductive layer, the low melting point conductive layer, and the second high melting point conductive layer may be layered in order on the insulating layer side. The second high melting point conductive layer may have a relatively higher melting point than that of the low melting point conductive layer. In any case, an awning shape is formed in the first conductive layer. However, the insulating layer for covering the first conductive layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Thus, the generation of the above-mentioned cracks is prevented or suppressed. Further, in the above electronic device, the thickness of the insulating layer may be larger than the thickness of the first conductive layer. In this case, the insulating layer can be thickened to decrease the parasitic capacitance between the conductive layers. On the other hand, constrictions are likely to be generated as compared to the case that an insulating layer is thinner than the first conductive layer. However, the generation of constrictions is suitably prevented or suppressed because the insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Next, in order to achieve the above object, the invention can provide a method of manufacturing a semiconductor device having a step of forming a layered structure. The step of forming the layered structure can include the steps of forming a semiconductor layer on a base, forming a gate insulating layer on the semiconductor layer, forming a gate electrode having a predetermined pattern on the gate insulating layer, forming an interlayer insulating layer mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher on the gate electrode, and forming a conductive layer on the interlayer insulating layer. As described above, the interlayer insulating layer is mainly made of silicon oxynitride (represented by the composition formula: SixOyNz, where x, y and z are natural numbers) with a nitrogen concentration of 2 atomic percent or higher between the gate electrode and the conductive layer. As a result, a film stress generated when the interlayer insulating layer is thickened can be reduced. Hence, according to the method of manufacturing the semiconductor device of the invention, for example, even when the interlayer insulating layer is thickened to decrease the parasitic capacitance between the gate electrode and the conductive layer, the film stress can be reduced, and the generation of cracks in the interlayer insulating layer can be prevented or suppressed. Further, for example, even when the gate electrode has an acute shape, the generation of constrictions in the interlayer insulating layer corresponding to the acute shape is decreased, and the short-circuiting hardly occurs in the conductive layer formed on the interlayer insulating layer. Thus, the invention can provide a semiconductor device with a high reliability. Further, if annealing is performed after a stable interlayer insulating layer with few cracks is formed in such a state that the nitrogen concentration is relatively high, the nitrogen concentration of the interlayer insulating layer can be decreased. Consequently, the insulating layer can be thickened to reduce the parasitic capacitance between the gate electrode and the conductive layers, and the parasitic capacitance can be reduced by the low dielectric constant due to a decrease in the nitrogen concentration of the interlayer insulating layer. In other words, according to the method of manufacturing a semiconductor device of the present invention, the interlayer insulating layer can be thickened without causing troubles occurring in the conventional method of manufacturing a semiconductor device, and because the dielectric constant is lowered by annealing of the interlayer insulating layer. Thus, the parasitic capacitance between the gate electrode and the conductive layers can be decreased without lowering the reliability, thereby further improving the reliability of a semiconductor device to be manufactured. Particularly, the problems, such as the generation of cracks in the interlayer insulating layer or short-circuiting in the conductive layer due to the thick interlayer insulating layer, are completely solved, so that the parasitic capacitance between the gate electrode and the conductive layers can be decreased without troubles. Thus, the manufacturing method of the invention can provide a semiconductor device with a high reliability, in which the interlayer insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the gate electrode and the conductive layer. Further, in the manufacturing method of the invention, the annealing may include heat annealing based on heating, specifically, the annealing may be performed in a water vapor atmosphere, in an oxygen atmosphere, and in a hydrogen atmosphere. By performing such annealing, the nitrogen concentration is lowered to 0.5 atomic percent or lower. In other words, according to the manufacturing method of the invention, after an insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed, the annealing is performed under the conditions that the nitrogen concentration is 0.5 atomic percent or lower. Moreover, in the above manufacturing method of the semiconductor device, the gate electrode forming step may include the steps of forming a relatively low melting point layer, and forming a relatively high melting point layer on the low melting point layer. In this case, for example, when a gate electrode is formed to have a predetermined pattern by etching, the low melting point conductive layer is likely to become relatively narrowed by side-etching and the high melting point layer is likely to have an awning shape. Thus, in the case where a conventional interlayer insulating layer made of silicon oxide is formed so as to cover the gate electrode, the above-mentioned constrictions are more likely to be generated. However, according to the manufacturing of the invention, even if an interlayer insulating layer is formed on the gate electrode having such a awning shape, constrictions is hardly generated, that is, constrictions hardly occurs because an interlayer insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed. Specifically, for example, a low melting point layer may include a layer mainly made of aluminum, and the high melting point layer may comprise a layer mainly made of metal nitride. Further, in the interlayer insulating layer forming step, the thickness of the interlayer insulating layer may be larger than that of the gate electrode. In this case, the interlayer insulating layer is thickened to decrease the parasitic capacitance between the gate electrode and the conductive layer. On the other hand, constrictions are likely to be generated as compared to the case that an interlayer insulating layer is thinner than the gate electrode. However, the generation of constrictions is suitably prevented or suppressed because the interlayer insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Moreover, in the semiconductor device manufactured by such a method, with each layer being layered along upper and lower directions, the interlayer insulating layer at the side of the gate electrode has a larger nitrogen content than the interlayer insulating layer on the gate electrode. Specifically, the interlayer insulating layer on the gate electrode has a nitrogen content of less than 0.5 atomic percent. On the other hand, the interlayer insulating layer at the side of the gate electrode has a nitrogen content of 0.5 atomic percent or higher, preferably, 2.0 atomic percent or higher. For example, such nitrogen contents can be measured using an elementary analysis (energy-dispersed type X-ray analysis, such as ESCA (electron spectroscopy for chemical analysis including SIMS (secondary ion mass spectrometry), AES (auger electron spectroscopy), XPS (X-ray photoelectron spectroscopy), etc.)). Further, the semiconductor device of the present invention comprises a semiconductor layer formed on a base, a gate insulting layer formed on the semiconductor layer, a gate electrode formed on the gate insulating layer, and an interlayer insulating layer formed on the gate electrode, and a conductive layer formed on the interlayer insulating layer. At least the interlayer insulating layer at the side of the gate electrode is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. According to such a construction, the generation of constrictions is suitably prevented or suppressed. Further, the interlayer insulating layer formed between the gate electrode and the conductive layer is mainly made of silicon oxynitride with a nitrogen concentration of 0.5 atomic percent or lower. Consequently, the insulating layer can be thickened to reduce the parasitic capacitance between the gate electrode and the conductive layers, and the dielectric constant due to a decrease in the nitrogen concentration of the interlayer insulating layer can be lowered to reduce the parasitic capacitance. Further, in the semiconductor device of the present invention, the interlayer insulating layer formed between the gate electrode and the conductive layer may be mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. The generation of constrictions can be more suitably prevented or suppressed by such a construction. The interlayer insulating layer other than at the side of the gate electrode may be mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. In this case, the interlayer insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Thus, even when the interlayer insulating layer is thickened to decrease the parasitic capacitance between the gate electrode and the conductive layer, the film stress generated in the interlayer insulating layer can be reduced, and the generation of cracks in the interlayer insulating layer can be prevented or suppressed. Further, for example, even when the gate electrode has an acute shape, the generation of constrictions in the interlayer insulating layer corresponding to the acute shape is also decreased. As a result, the short-circuiting hardly occurs in the conductive layer formed on the insulating layer so that a semiconductor device with a high reliability can be provided. In other words, according to the above semiconductor device, the interlayer insulate layer can be thickened without causing troubles occurring in the conventional semiconductor device. Thus, the parasitic capacitance between the gate electrode and the conductive layers can be decreased without deteriorating the reliability, thereby further enhancing the reliability of the semiconductor device. Particularly, the problems, such as the generation of cracks in the interlayer insulating layer due to the thickened layer and the short-circuiting in the conductive layer due to the thickened layer are completely solved, so that the parasitic capacitance between the gate electrode and the conductive layers can be decreased without troubles. Accordingly, the invention can provide a semiconductor device with a high reliability, in which an interlayer insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the conductive layers. Moreover, in the above semiconductor device, the insulating layer may have a refractive index of 1.5 or higher. Further, in the above semiconductor device, the gate electrode has a layered structure comprising a low melting point layer, and a high melting point layer. The high melting point layer is arranged on the side of the interlayer insulating layer. In this case, for example, when the gate electrode is formed to have a predetermined pattern by etching, the low melting point layer is likely to become relatively narrowed by side-etching and the high melting point layer is likely to have an awning shape. Thus, in the case where an interlayer insulating layer is formed so as to cover such the gate electrode, the above-mentioned constrictions are more likely to be generated. However, in the structure of the semiconductor device as described above, even if the interlayer insulating layer covers the gate electrode having such awning shape, constrictions are hardly generated, that is, the parasitic capacitance between the gate electrode and the conductive layers is decreased. Thus, the interlayer insulating layer can be thickened without problems. As a specific structure of the gate electrode, for example, the low melting point layer can include a layer mainly made of aluminum, and the high melting point layer comprises a layer mainly made of metal nitride. Also, for example, the high melting point layer, the low melting point layer, and the high melting point metal layer may be layered in order from the interlayer insulating layer side. Here, the high melting point metal layer has a melting point higher than that of the low melting point layer. In any case, an awning shaped is formed in the gate electrode. However, the interlayer insulating layer for covering the gate electrode is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Thus, the generation of cracks as described above is prevented or suppressed. Further, the thickness of the interlayer insulating layer may be larger than the thickness of the gate electrode. In this case, the interlayer insulating layer can be thickened to decrease the parasitic capacitance between the gate electrode and the conductive layers. On the other hand, constrictions are likely to be generated as compared to the case that an interlayer insulating layer is thinner than the gate electrode. However, the generation of constrictions is suitably prevented or suppressed because the interlayer insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with reference to the accompanying drawings, wherein like numerals reference like elements, and wherein: FIG. 1 is a schematic sectional view illustrating a semiconductor device according to an embodiment of the present invention; FIG. 2 is a schematic sectional view illustrating a semiconductor device according to a comparative example; FIG. 3 is a schematic sectional view illustrating a modification of the semiconductor device in FIG. 1; FIG. 4 is a sectional view schematically illustrating processes of manufacturing the semiconductor device in FIG. 1; FIG. 5 is a sectional view schematically illustrating processes of manufacturing the semiconductor device, subsequent to the processes of FIG. 4; FIG. 6 is a schematic sectional view schematically illustrating processes of manufacturing the semiconductor device, subsequent to the processes of FIG. 5; FIG. 7 is schematic sectional views illustrating a process of manufacturing the semiconductor device, following the process of FIG. 6; and FIG. 8 is a sectional view schematically illustrating the structure of the semiconductor device after annealing. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Embodiments according to the invention will now be described with reference to the accompanying drawings. FIG. 1 is a schematic sectional view illustrating the schematic structure of a thin film transistor (a semiconductor device) as an embodiment of an electronic device obtained by a manufacturing method of the present invention; and FIG. 2 is a schematic sectional view illustrating the schematic structure of a semiconductor device of a comparative example. In addition, it should be understood that scales of respective layers and members in the respective drawings are made different from each other so that the respective layers and members have sizes capable of being recognized in the drawings. As illustrated in FIG. 1, a thin film transistor (TFT) 100 is an N-channel type polycrystalline silicon TFT having a polycrystalline silicon film 22 formed on a glass substrate (base) 10 via a base protective film 11. The polycrystalline silicon film 22 can include a high concentration source region 22d, a low concentration source region 22b, a channel region 22a, a low concentration drain region 22c, and a high concentration drain region 22e. A source electrode 36 is electrically connected to the high concentration source region 22d via a contact hole 34, and a drain electrode 37 is electrically connected to the high concentration drain region 22e via a contact hole 35. Further, a gate electrode 32 is formed on the channel region 22a of the polycrystalline silicon film 22 via a gate electrode 31. Such TFT 100 is suitable as a pixel switching element of, for example, an electroluminescent device used as a representative liquid crystal display (LCD) In this case, the drain electrode 37 is employed as a pixel electrode. Here, the source electrode 36 and the drain electrode 37 are opposed to each other with respect to the gate electrode 32, with an interlayer insulating film 33 therebetween. Therefore, parasitic capacitance is generated between the opposed electrodes 36 and 37, and the parasitic capacitance may deteriorate the properties of the transistor. In order to decrease the parasitic capacitance, for example, it is effective that the interlayer insulating film 33 arranged between the source electrode 36 and the gate electrode 32 and between the drain electrode 37 and the gate electrode 32 is thickened. Thus, for example, as shown in FIG. 2, when an interlayer insulating film 33a mainly made of silicon oxide that is conventionally used is thickened, film stress is increased and a crack may occur in the interlayer insulating film 33a. Further, constrictions 36a and 37a may be generated in the interlayer insulating film 33a around the gate electrode 32 corresponding to a stepped shape due to the gate electrode 32. Thus, in the case where the constrictions 36a and 37a are generated in the interlayer insulating film 33a, a short circuit may occur in the source and drain electrodes 36 and 37 formed on the interlayer insulating film 33a along the constrictions 36a and 37a. However, in the TFT 100 according to the embodiment, even though the interlayer insulating film 33 is thickened to decrease the parasitic capacitance between the electrodes, a large film stress is not largely generated in the interlayer insulating film 33 because the interlayer insulating film 33 is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Further, when the interlayer insulating film 33 is formed on the gate electrode 32 having an acute shape, the generation of constrictions in the interlayer insulating film corresponding to the acute shape is reduced. Thus, the short-circuiting hardly occurs in the source and drain electrodes 36a and 37 formed on the interlayer insulating film 33a, thereby providing the TFT 100 having a high reliability. As shown in FIG. 3, in the case where the gate electrode 32 has a multi-layered structure including a plurality of layers that is different in their elements from each other, the above-mentioned constriction is more remarkably suppressed. Specifically, on the gate insulating film 31 are layered in order a relatively high melting point metal layer 32c, such as titanium, a low melting point metal layer 32b mainly made of aluminum, a high melting point metal layer 32a mainly made of metal nitride, such as titanium nitride. In this case, when the gate electrode 32 is etched to form a predetermined pattern, the low melting point metal layer 32b is likely to become relatively narrowed by side-etching. As a result, the high melting point metal layer 32a is likely to have an awning shape. Here, the first and second high melting point metal layers may preferably employ tungsten, tantalum, molybdenum, or chrome other than titanium. More preferably, nitride or oxide of high melting point metal may be employed a film having the layered structure having the high melting point may be formed. Thus, when the gate electrode 32 has the awning shape, the above-mentioned constriction is readily generated in the interlayer insulating layer 33. However, in the interlayer insulating film 33 according to the embodiment of the invention, even though the gate electrode 32 having the awning shape is covered with the interlayer insulating layer 33, a constriction is hardly generated, thereby preventing the source electrode 36 and the drain electrode 37 from short-circuiting, respectively. Further, according to the embodiment, the thickness (e.g., 800 nm) of the interlayer insulating film 33 is larger than the thickness (e.g., 400 nm) of the gate electrode 32. That is, the interlayer insulating film 33 is thickened in order to decrease the parasitic capacitance between the electrodes. On the other hand, even though the interlayer insulating film 33 is thicker than the gate electrode 32 and thus constrictions are easily generated, such problem is solved by the interlayer insulating film 33 mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. The TFT 100 of the embodiment as described can be manufactured by, for example, the following processes. Hereinafter, a method of manufacturing the TFT 100 will be described with reference to FIGS. 4 to 6. First, as shown in FIG. 4(a), a glass substrate 10 cleaned by ultrasonic cleaning is prepared. Under the conditions that the glass substrate 10 has a temperature of 150 to 450° C., the base protective film (shock-absorbing film) 11 formed of an insulating film, such as an silicon oxide film, is formed on the whole surface of the glass substrate 10. Specifically, the film formation is performed by a plasma chemical vapor deposition (CVD) method with a thickness of 10 μm or lower (e.g., about 500 nm). A source gas used in this process preferably includes a mixed gas of monosilane and nitrous oxide (N2O), tetraethoxysilane (TEOS) Si (OC2H5), oxygen, disilane, ammonia, etc. Next, as shown in FIG. 4(b), an amorphous silicon film (amorphous semiconductor film) 21 is formed by the plasma CVD method with a thickness of, for example, 30 to 100 nm on the entire surface of the glass substrate 10 having the base protective film 11 formed thereon under the conditions that the glass substrate 10 has a temperature of 150 to 450° C. A source gas used in this process preferably includes disilane or monosilane. Next, as shown in FIG. 4(c), laser annealing is performed, that is, a polycrystalline silicon film 22 is formed by applying light “L” of an excimer laser to the amorphous silicon film 21, wherein an XeCl-excimer laser uses a wavelength of 308 nm and a KrF-excimer laser uses a wavelength of 249 nm. Next, as shown in FIG. 4(d), the polycrystalline silicon film 22 is patterned by photolithography into an active layer to be formed. That is, a photoresist is applied onto the polycrystalline silicon film 22, and then the photoresist is treated by exposure and development. Then, the polycrystalline silicon film 22 is etched and the photoresist is removed, thereby patterning the polycrystalline silicon film 22. Alternatively, after patterning the amorphous silicon film 21, the polycrystalline silicon film 22 may be formed by performing the laser annealing. Next, as shown in FIG. 5(a), a gate insulating film 31 a silicon oxide film and/or a silicon nitride film is formed with a thickness of 50 to 150 nm (in this embodiment, 50 nm) on the whole surface of the glass substrate 10 having the polycrystalline silicon film 22 formed thereon under a temperature of 350° C. or lower. A source gas used in this process preferably includes a mixed gas of tetraethoxysilane (TEOS) and oxygen gas, etc. Next, as shown in FIG. 5(b), a conductive material including metal, such as aluminum, tantalum or molybdenum, or alloy mainly containing any one of them is formed by a sputtering method on the whole surface of the glass substrate 10 having the gate insulating film 31 formed thereon and is then patterned by the photolithography, thereby forming a gate electrode 32 having a thickness of 300 to 800 nm. That is, a photoresist is applied onto the glass substrate 10 having a film of conductive material formed thereon, and is then treated by exposure and development. Then, the conductive material is etched and the photoresist is removed, thereby patterning the conductive material and forming the gate electrode 32. Next, as shown in FIG. 5(c), doping ions (e.g., phosphorus ions) of a low concentration is implanted with a dose of about 0.1×1013/cm2 to 10×1013/cm2 are toward the gate electrode 32 used as a mask, thereby forming a low concentration source region 22b and a low concentration drain region 22c in a self-aligned manner with respect to the gate electrode 32. Here, a portion disposed directly under the gate electrode 32 and having no doping ions introduced thereinto is a channel region 22a. Further, as shown in FIG. 5(d), a resist mask (not shown) broader than the gate electrode 32 is formed, and then the doping ions (e.g., phosphorus ions) of a high concentration is implanted with a dose of about 0.1×1015/cm2 to 10×1015/cm2 toward the resist mask, thereby forming a high concentration source region 22d and a high concentration drain region 22e. Next, as shown in FIG. 6(a), annealing is performed by radiating lamp light SL onto the glass substrate 10 having the polycrystalline silicon film 22 as shown in FIG. 5(d). Specifically, the excimer laser annealing is performed in a reduced pressure atmosphere or in a nitrogen atmosphere, thereby activating the dopant implanted into the source regions 22b and 22d and the drain regions 22c and 22e. Next, as shown in FIG. 6(b), an interlayer insulating film 33 formed of a silicon oxynitride film is formed with a thickness of, for example, 400 to 900 nm by the CVD method on the upper surface (opposite to a surface facing the glass substrate 10) of the gate electrode 32. Specifically, a mixed gas of monosilane and nitrous oxide is used as a source gas and the flow ratios of the respective gases are appropriately set to obtain a silicon oxynitride film having a predetermined nitrogen concentration (in this embodiment, 2 atomic percent or higher). After the film is formed, the resist mask (not shown) having a predetermined pattern is formed, and then dry-etching is applied to the interlayer insulating film 33 through the resist mask. Thus, contact holes 34 and 35 are respectively formed in the portions of the interlayer insulating film 33 corresponding to the high concentration source region 22d and the high concentration drain region 22e. Next, as shown in FIG. 6(c), a film of conductive material including aluminum, titan, titan oxide, tantalum or molybdenum, or alloy mainly containing any one of them is formed by the sputtering method on the whole surface of the interlayer insulating film 33 having the gate insulating film 31 formed thereon, and is then patterned by the photolithography, thereby forming a source electrode 36 and a drain electrode 37 having a thickness of, for example, 400 to 800 nm. That is, a photoresist is applied onto the glass substrate 10 having a film of conductive material formed thereon, and is then treated by exposure and development. Then, the conductive material is etched and the photoresist is removed, thereby patterning the conductive material and forming a source electrode 36 and a drain electrode 37. As described above, an N-channel polycrystalline silicon TFT (semiconductor device) 100 can be manufactured. The obtained TFT (semiconductor device) 100 may be, as shown in FIG. 7, treated by annealing (e.g., laser annealing) AN. Through the annealing AN, the nitrogen concentration of the interlayer insulating film 33 is lowered, specifically, an N-channel type polycrystalline silicon TFT 400 can be, as shown in FIG. 8, manufactured with an interlayer insulating film 33c with a nitrogen concentration of 0.5 atomic percent or lower. In this case, the annealing AN is preferably performed in a water vapor atmosphere, in an oxygen atmosphere, and in a hydrogen atmosphere. Further, if the interlayer insulating film (silicon oxynitride film) 33 is formed through the CVD at a temperature of, for example, about 300° C., and is treated by the annealing at a temperature of about 300° C., the film forming process and the annealing process of the interlayer insulating film 33 can be performed in the same chamber, thereby performing simple continuous processes, for example, by just changing inflowing gas. From the manufacturing method including the annealing, the following effects are obtained. That is, in the manufacturing method according to the embodiment, when the interlayer insulating film 33 is formed, the silicon oxynitride film with a nitrogen concentration of 2 atomic percent or higher is formed, and is then treated by annealing, thereby decreasing the nitrogen concentration. Thus, problems (such as the generation of cracks or constrictions) occurring when the thick insulating film is formed can be solved, and the dielectric constant of the interlayer insulating film 33 can be lowered. That is, during the film forming process, as shown in FIG. 6(b), the interlayer insulating film 33 having a high nitrogen concentration is formed. Thus, a large film stress is not generated, and the generation of constrictions along the gate electrode 32 is reduced and the short-circuiting in the source and drain electrodes 36 and 37 formed on the insulating film 33 hardly occurs. Besides, such an intermediate product allowing a film to be thickened is annealed, so that the nitrogen concentration is decreased, thereby further lowering the dielectric constant. Specifically, the annealing allows the nitrogen concentration to be lowered to 0.5 atomic percent, and allows the parasitic capacitance to be decreased. That is, the TFT (semiconductor device) 400 shown in FIG. 8 has the parasitic capacitance between the gate electrode 32 and the source electrode 36 (or the drain electrode 37) that is lower than the parasitic capacitance of the TFT (semiconductor device) 100 (refer to FIG. 6(c)) as an intermediate product, thereby improving reliability. Specifically, the insulating film 33 has a dielectric constant of about 4.6 to 4.9, whereas the annealed insulating film 33s has a dielectric constant of about 3.9 to 4.2. Meanwhile, according to the manufacturing method of the present embodiment, the nitrogen concentration in forming the insulating film 33 is increased. Thus, the polycrystalline silicon film 22 is hardly dehydrogenated during the annealing process, which makes it possible to perform the annealing efficiently. Further, in the above-described manufacturing method, it is preferable that the interlayer insulating layer 33 at least at the side of the gate electrode 32 be mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. By forming the interlayer insulating layer in this way, the above-described constrictions hardly occur: in other words, short-circuiting hardly occurs in the source electrode 36 and the drain electrode 37. Further, the interlayer insulating layer 33 between the gate electrode 32 and the source electrode 36 or drain electrode 37 may be an insulating layer having a nitrogen concentration of 0.5 atomic percent or lower with annealing. Thus, the parasitic capacitance between the gate electrode 32 and the source electrode 36 or drain electrode 37 can be reduced due to an increase in the thickness of the interlayer insulating layer 33 and the parasitic capacitance can also be reduced by the low dielectric constant due to a decrease in the nitrogen concentration of the interlayer insulating layer 33. Further, the interlayer insulating layer 33 between the gate electrode 32 and the source electrode 36 or drain electrode 37 may be mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. In other words, the annealing process may be performed, or otherwise the interlayer insulating layer 33 may be mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Next, in order to make sure of the effects of the invention, the following evaluation was performed. That is, in the above-mentioned manufacturing method using the structure shown in FIG. 1, the flow ratio of monosilane and nitrous oxide when a interlayer insulating film 33 is formed is properly set so that TFTs according to Comparative Examples 1, 2 and 3 and Examples 1 and 2 are prepared to have the interlayer insulating film 33 having the nitrogen concentration (unit of N concentration: atomic percent) as shown in Table 1. As to the TFTs according to Comparative examples 1, 2 and 3 and Examples 1 and 2, the refractive index of each interlayer insulating film 33, and short-circuiting rate (indicated as a relative value when the short-circuiting rate of Comparative example 1 is 1.0) in the source and drain electrodes 36 and 37, and the film stress (indicated as a relative value when the film stress of Comparative example 1 is 1.0) were evaluated. The results of evaluation are shown in Table 1. TABLE 1 Refractive Short-circuiting Film N concentration index rate stress Comparative 0.5 1.47 1.0 1.0 example 1 Comparative 1.0 1.48 0.7 0.5 example 2 Comparative 1.5 1.49 0.3 0.4 example 3 Example 1 2.0 1.52 0.0 0.4 Example 2 5.0 1.55 0.0 0.3 As described above, the short-circuiting rate and the film stress show different values depending on the nitrogen concentration (N concentration) of the interlayer insulating film 33. Specifically, in Comparative examples 1 to 3 respectively with a nitrogen concentration of 0.5 to 1.5 atomic percent, short-circuiting may occur, the film stress is large, and a crack in the interlayer insulating film 33 may be generated. On the other hand, in Examples 1 and 2 using the interlayer insulating film 33 respectively with a nitrogen concentration of 2 atomic percent or higher, short-circuiting is avoided and the film stress is reduced. From the above results, the interlayer insulating film 33 is formed of silicon oxide with a nitrogen concentration of 2 atomic percent or higher when the interlayer insulating layer 33 is formed, thereby avoiding the problems such as short-circuiting, cracking, etc., which may occur when the thickness of the interlayer insulating layer 33 is increased. Accordingly, it can be understood that the parasitic capacitance between the gate electrode 32 and the source electrode 36 and between the gate electrode 32 and the drain electrode 37 can be decreased without trouble. As described above, although one embodiment of the invention has been described, it should be understood that the invention is not limited thereto, but the invention covers the range easily replaceable from the respective claims by one skilled in the art without being limited to the definitions as set forth in the respective claims as long as it does not depart from the scope as set forth in the respective claims. A proper improvement can also be made to the invention on the basis of ordinary knowledge of a person skilled in the art. For instance, although the method of manufacturing an N-channel type TFT has been described as an example in the embodiment, the manufacturing method of the invention can also be applied to a method of manufacturing a P-channel type TFT. Further, an application of the invention is not limited to the TFT, and the structure of the invention may be employed in a general electronic device with an insulating layer interposed between a pair of electrodes. Accordingly, while this invention has been described in conjunction with the specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. There are changes that may be made without departing from the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention The present invention relates to a method of manufacturing an electronic device and a method of manufacturing a semiconductor device. 2. Description of Related Art To realize large-scale integration (LSI) of electronic devices, such as semiconductor devices, wiring lines have recently become multi-layered. In electronic devices having such multi-layered wiring lines, upper and lower wiring patterns with an interlayer insulating film disposed therebetween are electrically connected to each other through contact holes formed in the interlayer insulating film. Here, in order to reduce the parasitic capacitance between the wiring lines, there have been proposed various methods of selecting a material having a low dielectric constant for the interlayer insulating film, making the interlayer insulating film thick, etc. Generally, silicon oxide is used as the material for the interlayer insulating film. However, if a silicon oxide film is thickened, film stress becomes larger, thereby causing cracks. Further, if the thick interlayer insulating film is formed on the wiring lines having an acute shape, constrictions (overhangs) are generated in the interlayer insulating film corresponding to the acute shape, so that there arises a problem that the wiring lines formed thereon is likely to short-circuit. Therefore, in order to avoid the influence due to the constrictions generated when the interlayer insulating film is formed on the wiring lines having the acute shape, for example, Japanese Unexamined Patent Application Publication No. 55-145356 discloses technology that phosphate glass is formed on the interlayer insulating film and then the wiring lines are formed on the glass. | <SOH> SUMMARY OF THE INVENTION <EOH>According to such technology disclosed above, short-circuiting which may be caused in wiring lines due to constrictions formed in the interlayer insulating film can be prevented or suppressed, but the parasitic capacitance between the wiring lines is not reduced. Also, the interlayer insulating film is formed to have a two-layered structure, so that it takes time to manufacture the interlayer insulating film, a stress based on the difference between the coefficients of thermal expansion of the layers is generated, and the film is peeled off. An object of the invention is to provide an electronic device or a semiconductor device or a semiconductor device capable of reducing the parasitic capacitance between layered wiring lines with an interlayer insulating film disposed therebetween. More particularly the invention can provide a method of manufacturing an electronic device and a method of manufacturing a semiconductor, which sweeps away troubles which may occur when the parasitic capacitance is reduced, and have a simple structure and high reliability. In order to solve the above problems, the invention can provide a method of manufacturing an electronic device including a step of forming a layered structure. The step of forming a layered structure can further include the steps of forming a first conductive layer having a predetermined pattern on a base, forming an insulating layer mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher on the first conductive layer, and forming a second conductive layer on the insulating layer. In the present specification, the mainly made of means including a component of the largest content among all components. As a result of study, it has been found that a film stress generated when the insulating layer is thickened can be controlled by the components of the insulating layer. That is, as described above, when a thick insulating layer mainly made of silicon oxynitride (represented by the composition formula: Si x O y N z , where x, y and z are natural numbers) with a nitrogen concentration of 2 atomic percent or higher between the first conductive layer and the second conductive layer is formed, it has been found that a film stress generated when the insulating layer is thickened is smaller than that of the conventional insulating layer. Therefore, according to the method of manufacturing an electronic device of the invention, for example, even though a thick insulating layer is formed to reduce the parasitic capacitance between the conductive layers, the film stress can be decreased, thereby preventing or suppressing the generation of cracks in the insulating layer. Also, for example, even though the first conductive layer has an acute shape, the generation of constrictions in the insulating layer corresponding to the acute shape can be reduced and the short-circuiting hardly occurs in the second conductive layer formed on the insulating layer, thereby providing an electronic device with a high reliability. Further, if annealing is performed after a stable insulating layer with few cracks is formed in such a state that the nitrogen concentration is relatively high, the nitrogen concentration of the insulating layer can be decreased. Consequently, the insulating layer can be thickened to reduce the parasitic capacitance between the conductive layers and the parasitic capacitance can also be reduced by the low dielectric constant due to a decrease in the nitrogen concentration of the insulating layer. That is, according to the method of manufacturing an electronic device of the invention, the insulating layer can be thickened without causing troubles occurring in the conventional method of manufacturing an electronic device, and the parasitic capacitance between the conductive layers can be decreased without lowering the reliability because the dielectric constant is lowered in the case where the insulating layer is annealed, thereby improving the reliability of the electronic device to be manufactured. Particularly, the problems such as the generation of cracks in the insulating layer or short-circuiting in the conductive layer due to the thickened insulating layer are completely solved, so that the parasitic capacitance between the conductive layers can be decreased without troubles. Thus, the manufacturing method of the invention can provide an electronic device with a high reliability, in which an insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the conductive layers. In the manufacturing method of the invention, the annealing may include heat annealing based on heating, specifically, the annealing may be performed in a water vapor atmosphere, in an oxygen atmosphere, and in a hydrogen atmosphere. By performing such annealing, the nitrogen concentration of the insulating layer is lowered to 0.5 atomic percent or lower. In other words, according to the manufacturing method of the invention, after an insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed, the annealing is performed under the conditions that the nitrogen concentration of the insulating layer is 0.5 atomic percent or lower. Further, in the manufacturing method of the invention, the first conductive layer forming step may include the steps of forming a relatively low melting point conductive layer on the base, and forming a first relatively high melting point conductive layer on the low melting point conductive layer. In this case, for example, when the first conductive layer is formed to have a predetermined pattern by etching, the low melting point conductive layer is likely to become relatively narrowed by side-etching and the first high melting point conductive layer is likely to have an awning shape. Thus, in the case where a conventional insulating layer made of silicon oxide is formed so as to cover the first conductive layer, the above-mentioned constrictions are more likely to be generated. However, according to the manufacturing method of the present invention, even if the insulating layer is formed on the first conductive layer having such awning shape, a constriction is hardly generated, that is, constrictions are hardly generated because an insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed. Specifically, for example, the low melting point conductive layer may comprise a layer mainly made of aluminum, and the high melting point conductive layer may comprise a layer mainly made of nitride. Besides, for example, the first conductive layer forming step may include the steps of forming a first relatively high melting point conductive layer on the base, forming a relatively low melting point conductive layer on the first high melting point conductive layer, and forming a second relatively high melting point conductive layer on the low melting point conductive layer. The second relatively high melting point conductive layer has a melting point higher than that of the low melting point conductive layer. Moreover, the low melting point conductive layer may include a layer mainly made of aluminum, and the second high melting point conductive layer may include a layer mainly made of any one of high purity metal, metal nitride, and metal oxide. In any case, an awing shape is formed in the first conductive layer etching step, and an insulating layer for covering the first conductive layer includes a layer mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher, thereby preventing or suppressing the generation of the above-mentioned cracks. Further, the insulating layer may be formed to be thicker than the first conductive layer during the insulating layer forming step. In this case, the insulating layer can be thickened to decrease the parasitic capacitance between the conductive layers is decreased. On the other hand, constrictions are likely to be generated as compared to the case that an insulating layer is thinner than the first conductive layer. However, the generation of constrictions is suitably prevented or suppressed because an insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Moreover, the following structure obtained as an intermediate product in the manufacturing method of the invention may also be suitably used as an electronic device. That is, the invention can provide an electronic device having a first conductive layer having a predetermined pattern, an insulated layer formed so as to cover the first conductive layer, and a second conductive layer formed on the insulating layer. The insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. As described above, in the electronic device comprising an insulating layer mainly made of silicon oxynitride (represented by the composition formula: Si x O y N z , where x, y and z are natural numbers) with a nitrogen concentration of 2 atomic percent or higher between the first and second conductive layers, a film stress generated when the insulating layer is thickened is relatively lower than that of the conventional electronic device. Hence, according to the above-mentioned electronic device, for example, even when the insulating layer is thickened to decrease the parasitic capacitance between the conductive layers, the film stress can be reduced, thereby preventing or suppressing the generation of cracks in the insulating layer. Further, for example, even when the first conductive layer has an acute shape, the generation of constrictions in the insulating layer corresponding to the acute shape is decreased, and the short-circuiting hardly occurs in the second conductive layer formed on the insulating layer. In other words, according to the above-mentioned electronic device, since an insulating layer can be thickened without causing troubles occurring in the conventional electronic device, the parasitic capacitance between the conductive layers can be decreased, thereby farther enhancing the reliability of the electronic device. Particularly, the problems such as the generation of cracks in the insulating layer due to the thickened layer and the short-circuiting in the conductive layer due to the thickened layer are completely solved, so that the parasitic capacitance between the conductive layers can be decreased without troubles. Therefore, the invention can provide an electronic device with a high reliability, in which an insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the conductive layers. Moreover, in the above electronic device, the insulating layer may have a refractive index of 1.5 or higher (measured wavelength of 632 nm). Further, in the above electronic device, the first conductive layer may have a layered structure having a low melting point conductive layer, and a first high melting point conductive layer. The first high melting point conductive layer may be arranged on the side of the insulating layer. In this case, for example, when the first conductive layer is formed to have a predetermined pattern by etching, the low melting point conductive layer is likely to become relatively narrowed by side-etching and the first high melting point conductive layer is likely to have an awning shape. Therefore, in the case where a conventional insulating layer made of silicon oxide is formed so as to cover the first conductive layer, the above-mentioned constrictions are more likely to be formed. However, in the structure of the above electronic device, even if the insulating layer is formed on the first conductive layer having such an awning shape, constrictions are hardly generated, that is, the parasitic capacitance between the conductive layers can be decreased. Thus, the insulating layer can be thickened without problems. As a specific structure of the above first conductive layer, for example, the low melting point conductive layer may have a layer mainly made of aluminum, and the first high melting point conductive layer is made of any one of high purity metal, metal nitride, and metal oxide. Further, for example, the high melting point conductive layer, the low melting point conductive layer, and the second high melting point conductive layer may be layered in order on the insulating layer side. The second high melting point conductive layer may have a relatively higher melting point than that of the low melting point conductive layer. In any case, an awning shape is formed in the first conductive layer. However, the insulating layer for covering the first conductive layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Thus, the generation of the above-mentioned cracks is prevented or suppressed. Further, in the above electronic device, the thickness of the insulating layer may be larger than the thickness of the first conductive layer. In this case, the insulating layer can be thickened to decrease the parasitic capacitance between the conductive layers. On the other hand, constrictions are likely to be generated as compared to the case that an insulating layer is thinner than the first conductive layer. However, the generation of constrictions is suitably prevented or suppressed because the insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Next, in order to achieve the above object, the invention can provide a method of manufacturing a semiconductor device having a step of forming a layered structure. The step of forming the layered structure can include the steps of forming a semiconductor layer on a base, forming a gate insulating layer on the semiconductor layer, forming a gate electrode having a predetermined pattern on the gate insulating layer, forming an interlayer insulating layer mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher on the gate electrode, and forming a conductive layer on the interlayer insulating layer. As described above, the interlayer insulating layer is mainly made of silicon oxynitride (represented by the composition formula: Si x O y N z , where x, y and z are natural numbers) with a nitrogen concentration of 2 atomic percent or higher between the gate electrode and the conductive layer. As a result, a film stress generated when the interlayer insulating layer is thickened can be reduced. Hence, according to the method of manufacturing the semiconductor device of the invention, for example, even when the interlayer insulating layer is thickened to decrease the parasitic capacitance between the gate electrode and the conductive layer, the film stress can be reduced, and the generation of cracks in the interlayer insulating layer can be prevented or suppressed. Further, for example, even when the gate electrode has an acute shape, the generation of constrictions in the interlayer insulating layer corresponding to the acute shape is decreased, and the short-circuiting hardly occurs in the conductive layer formed on the interlayer insulating layer. Thus, the invention can provide a semiconductor device with a high reliability. Further, if annealing is performed after a stable interlayer insulating layer with few cracks is formed in such a state that the nitrogen concentration is relatively high, the nitrogen concentration of the interlayer insulating layer can be decreased. Consequently, the insulating layer can be thickened to reduce the parasitic capacitance between the gate electrode and the conductive layers, and the parasitic capacitance can be reduced by the low dielectric constant due to a decrease in the nitrogen concentration of the interlayer insulating layer. In other words, according to the method of manufacturing a semiconductor device of the present invention, the interlayer insulating layer can be thickened without causing troubles occurring in the conventional method of manufacturing a semiconductor device, and because the dielectric constant is lowered by annealing of the interlayer insulating layer. Thus, the parasitic capacitance between the gate electrode and the conductive layers can be decreased without lowering the reliability, thereby further improving the reliability of a semiconductor device to be manufactured. Particularly, the problems, such as the generation of cracks in the interlayer insulating layer or short-circuiting in the conductive layer due to the thick interlayer insulating layer, are completely solved, so that the parasitic capacitance between the gate electrode and the conductive layers can be decreased without troubles. Thus, the manufacturing method of the invention can provide a semiconductor device with a high reliability, in which the interlayer insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the gate electrode and the conductive layer. Further, in the manufacturing method of the invention, the annealing may include heat annealing based on heating, specifically, the annealing may be performed in a water vapor atmosphere, in an oxygen atmosphere, and in a hydrogen atmosphere. By performing such annealing, the nitrogen concentration is lowered to 0.5 atomic percent or lower. In other words, according to the manufacturing method of the invention, after an insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed, the annealing is performed under the conditions that the nitrogen concentration is 0.5 atomic percent or lower. Moreover, in the above manufacturing method of the semiconductor device, the gate electrode forming step may include the steps of forming a relatively low melting point layer, and forming a relatively high melting point layer on the low melting point layer. In this case, for example, when a gate electrode is formed to have a predetermined pattern by etching, the low melting point conductive layer is likely to become relatively narrowed by side-etching and the high melting point layer is likely to have an awning shape. Thus, in the case where a conventional interlayer insulating layer made of silicon oxide is formed so as to cover the gate electrode, the above-mentioned constrictions are more likely to be generated. However, according to the manufacturing of the invention, even if an interlayer insulating layer is formed on the gate electrode having such a awning shape, constrictions is hardly generated, that is, constrictions hardly occurs because an interlayer insulating layer with a nitrogen concentration of 2 atomic percent or higher is formed. Specifically, for example, a low melting point layer may include a layer mainly made of aluminum, and the high melting point layer may comprise a layer mainly made of metal nitride. Further, in the interlayer insulating layer forming step, the thickness of the interlayer insulating layer may be larger than that of the gate electrode. In this case, the interlayer insulating layer is thickened to decrease the parasitic capacitance between the gate electrode and the conductive layer. On the other hand, constrictions are likely to be generated as compared to the case that an interlayer insulating layer is thinner than the gate electrode. However, the generation of constrictions is suitably prevented or suppressed because the interlayer insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Moreover, in the semiconductor device manufactured by such a method, with each layer being layered along upper and lower directions, the interlayer insulating layer at the side of the gate electrode has a larger nitrogen content than the interlayer insulating layer on the gate electrode. Specifically, the interlayer insulating layer on the gate electrode has a nitrogen content of less than 0.5 atomic percent. On the other hand, the interlayer insulating layer at the side of the gate electrode has a nitrogen content of 0.5 atomic percent or higher, preferably, 2.0 atomic percent or higher. For example, such nitrogen contents can be measured using an elementary analysis (energy-dispersed type X-ray analysis, such as ESCA (electron spectroscopy for chemical analysis including SIMS (secondary ion mass spectrometry), AES (auger electron spectroscopy), XPS (X-ray photoelectron spectroscopy), etc.)). Further, the semiconductor device of the present invention comprises a semiconductor layer formed on a base, a gate insulting layer formed on the semiconductor layer, a gate electrode formed on the gate insulating layer, and an interlayer insulating layer formed on the gate electrode, and a conductive layer formed on the interlayer insulating layer. At least the interlayer insulating layer at the side of the gate electrode is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. According to such a construction, the generation of constrictions is suitably prevented or suppressed. Further, the interlayer insulating layer formed between the gate electrode and the conductive layer is mainly made of silicon oxynitride with a nitrogen concentration of 0.5 atomic percent or lower. Consequently, the insulating layer can be thickened to reduce the parasitic capacitance between the gate electrode and the conductive layers, and the dielectric constant due to a decrease in the nitrogen concentration of the interlayer insulating layer can be lowered to reduce the parasitic capacitance. Further, in the semiconductor device of the present invention, the interlayer insulating layer formed between the gate electrode and the conductive layer may be mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. The generation of constrictions can be more suitably prevented or suppressed by such a construction. The interlayer insulating layer other than at the side of the gate electrode may be mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. In this case, the interlayer insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Thus, even when the interlayer insulating layer is thickened to decrease the parasitic capacitance between the gate electrode and the conductive layer, the film stress generated in the interlayer insulating layer can be reduced, and the generation of cracks in the interlayer insulating layer can be prevented or suppressed. Further, for example, even when the gate electrode has an acute shape, the generation of constrictions in the interlayer insulating layer corresponding to the acute shape is also decreased. As a result, the short-circuiting hardly occurs in the conductive layer formed on the insulating layer so that a semiconductor device with a high reliability can be provided. In other words, according to the above semiconductor device, the interlayer insulate layer can be thickened without causing troubles occurring in the conventional semiconductor device. Thus, the parasitic capacitance between the gate electrode and the conductive layers can be decreased without deteriorating the reliability, thereby further enhancing the reliability of the semiconductor device. Particularly, the problems, such as the generation of cracks in the interlayer insulating layer due to the thickened layer and the short-circuiting in the conductive layer due to the thickened layer are completely solved, so that the parasitic capacitance between the gate electrode and the conductive layers can be decreased without troubles. Accordingly, the invention can provide a semiconductor device with a high reliability, in which an interlayer insulating layer with a high barrier property, a good coverage shape, and a low film stress is disposed between the conductive layers. Moreover, in the above semiconductor device, the insulating layer may have a refractive index of 1.5 or higher. Further, in the above semiconductor device, the gate electrode has a layered structure comprising a low melting point layer, and a high melting point layer. The high melting point layer is arranged on the side of the interlayer insulating layer. In this case, for example, when the gate electrode is formed to have a predetermined pattern by etching, the low melting point layer is likely to become relatively narrowed by side-etching and the high melting point layer is likely to have an awning shape. Thus, in the case where an interlayer insulating layer is formed so as to cover such the gate electrode, the above-mentioned constrictions are more likely to be generated. However, in the structure of the semiconductor device as described above, even if the interlayer insulating layer covers the gate electrode having such awning shape, constrictions are hardly generated, that is, the parasitic capacitance between the gate electrode and the conductive layers is decreased. Thus, the interlayer insulating layer can be thickened without problems. As a specific structure of the gate electrode, for example, the low melting point layer can include a layer mainly made of aluminum, and the high melting point layer comprises a layer mainly made of metal nitride. Also, for example, the high melting point layer, the low melting point layer, and the high melting point metal layer may be layered in order from the interlayer insulating layer side. Here, the high melting point metal layer has a melting point higher than that of the low melting point layer. In any case, an awning shaped is formed in the gate electrode. However, the interlayer insulating layer for covering the gate electrode is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. Thus, the generation of cracks as described above is prevented or suppressed. Further, the thickness of the interlayer insulating layer may be larger than the thickness of the gate electrode. In this case, the interlayer insulating layer can be thickened to decrease the parasitic capacitance between the gate electrode and the conductive layers. On the other hand, constrictions are likely to be generated as compared to the case that an interlayer insulating layer is thinner than the gate electrode. However, the generation of constrictions is suitably prevented or suppressed because the interlayer insulating layer is mainly made of silicon oxynitride with a nitrogen concentration of 2 atomic percent or higher. | 20040708 | 20070109 | 20050210 | 83468.0 | 0 | QUACH, TUAN N | METHOD OF MANUFACTURING ELECTRONIC DEVICE AND METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,885,745 | ACCEPTED | Manufacturing method of flying magnetic head slider | A manufacturing method of a flying magnetic head slider includes a step of providing a substrate with a plurality of inductive write head elements formed thereon, each head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering the plurality of inductive write head elements, a step of cutting the substrate to separate into a plurality of bar members, each of the bar members having aligned inductive write head elements, a step of processing the protection layer of each bar member so that a distance from an end edge of the pair of magnetic poles to an edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm, a step of lapping each bottom surface of the bar member, and cutting each bar member to separate into a plurality of individual magnetic head sliders. | 1. A manufacturing method of a flying magnetic head slider comprising the steps of: providing a substrate with a plurality of inductive write head elements formed thereon, each head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering said plurality of inductive write head elements; cutting said substrate to separate into a plurality of bar members, each of said bar members having aligned inductive write head elements; processing said protection layer of each bar member so that a distance from an end edge of said pair of magnetic poles to an edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm; lapping each bottom surface of said bar member; and cutting each bar member to separate into a plurality of individual magnetic head sliders. 2. The manufacturing method as claimed in claim 1, wherein said processing step comprises chamfering a corner edge of said protection layer between a first end surface near which said inductive write head elements are formed and said bottom surface to form a chamfered section so that a distance from the end edge of said pair of magnetic poles to the edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm. 3. The manufacturing method as claimed in claim 2, wherein said processing step comprises chamfering said corner edge to form said chamfered section with an angle in a range of 20 to 70 degrees with respect to said bottom surface. 4. The manufacturing method as claimed in claim 1, wherein said processing step comprises etching said bottom surface so that a distance from the end edge of said pair of magnetic poles to the edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm. 5. The manufacturing method as claimed in claim 1, wherein said lapping step comprises lapping the bottom surface of said bar member using diamond abrasive grains. 6. The manufacturing method as claimed in claim 1, wherein said providing step comprises providing a substrate with a plurality of magnetoresistive effect read head elements, with a plurality of inductive write head elements, each inductive write head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering said plurality of magnetoresistive effect read head elements and said plurality of inductive write head elements. 7. A manufacturing method of a flying magnetic head slider comprising the steps of: providing a substrate with a plurality of inductive write head elements formed thereon, each head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer made of a resist material, covering said plurality of inductive write head elements, said protection layer on an end edge of said pair of magnetic poles having a thickness in a range of 10 to 15 μm; cutting said substrate to separate into a plurality of bar members, each of said bar members having aligned inductive write head elements; etching a bottom surface of each bar member; and cutting each bar member to separate into a plurality of individual magnetic head sliders. 8. The manufacturing method as claimed in claim 7, wherein said etching step comprises ion-milling the bottom surface of the bar member. 9. The manufacturing method as claimed in claim 7, wherein said providing step comprises providing a substrate with a plurality of magnetoresistive effect read head elements, with a plurality of inductive write head elements, each inductive write head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering said plurality of magnetoresistive effect read head elements and said plurality of inductive write head elements. | PRIORITY CLAIM This application claims priority from Japanese patent application No.2003-194915, filed on Jul. 10, 2003, which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method of a flying magnetic head slider provided with a thin-film magnetic head element. 2. Description of the Related Art In a magnetic disk drive device, thin-film magnetic head elements for writing magnetic information into and/or reading magnetic information from magnetic disks are in general formed on magnetic head sliders flying in operation above the rotating magnetic disks. The sliders are supported at top end sections of suspensions, respectively. Recently, a flying height of the magnetic head slider rapidly lowers to satisfy the requirement for ever increasing data storage capacities and densities in today's magnetic disk drive apparatus. Because of such lowered flying height, a possible protrusion of a protection layer of the slider at a corner portion between an air bearing surface (ABS) and a trailing surface, which corner is the lowest portion of the slider during the flying operations has not become negligible. Particularly, in the magnetic head slider with an inductive write head element, a protection layer may thermally expand and protrude due to the write current causing the protruded portion to come into contact with the magnetic disk surface during operations. Known is a method of forming a step or recess at a corner edge between the ABS and the trailing surface of the magnetic head slider, by partially removing the protection layer during a patterning process of the ABS, to reduce the protrusion of the protection layer as small amount as possible. In another known method disclosed for example in U.S. Pat. No. 6,428,715 B1, protrusion of a protection or overcoat layer made of a typical material of alumina (Al2O3) is reduced by immersing the overcoat layer in an alkaline solution and thus by etching the whole ABS of the overcoat layer to form a step. However, according to the former known method, due to the limited resolution of a resist and the limited precision in an exposure equipment used for patterning the ABS, it is impossible to bring a starting point of the step close to a magnetic pole of the inductive write head element. Therefore, the protrusion amount cannot be reduced so much. If the step is formed over a part of the magnetic pole, a coating film such as a diamond like carbon (DLC) film is removed causing corrosion of the pole to occur. According to the latter known method, it is ensured to etch the alumina and to form a step. However, if the magnetic pole contains a metal material easily etched by an alkaline, the pole itself is etched to deteriorate the characteristics of the write head element. BRIEF SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a manufacturing method of a flying magnetic head slider, whereby manufacturing process becomes easy. Another object of the present invention is to provide a manufacturing method of a flying magnetic head slider, whereby protrusion of a protection layer can be reduced without adversely affecting head element characteristics. According to the present invention, a manufacturing method of a flying magnetic head slider includes a step of providing a substrate with a plurality of inductive write head elements formed thereon, each head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering the plurality of inductive write head elements, a step of cutting the substrate to separate into a plurality of bar members, each of the bar members having aligned inductive write head elements, a step of processing the protection layer of each bar member so that a distance from an end edge of the pair of magnetic poles to an edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm, a step of lapping each bottom surface of the bar member, and cutting each bar member to separate into a plurality of individual magnetic head sliders. After shortening the distance from an end edge of the pair of magnetic poles to an edge of the bottom surface of the bar member becomes in a range of 1 to 15 μm, the bottom surface of the bar member is lapped. Thus, the corner edge of the protection layer is rounded off or more shaved. The rounded edge is produced because the outer region of the lapped surface is shaved greater than its inner region depending upon the lapping direction, the lapping pressure and the abrasive plate material. Because the corner edge is formed to have a curved cross sectional profile, the end edge of the bottom surface to be near to the upper magnetic pole of the inductive write head element, so as to back off the surface of the protection layer. Therefore, it is possible to reduce the amount of the thermal expansion protrusion of the protection layer toward the ABS due to write current during writing operations. Particularly, according to the present invention, because the end edge of the bottom surface is inherently rounded by merely performing the lapping, the manufacturing process becomes quite easy. Also, since this method will induce no damage to the magnetic pole, the thermal expansion protrusion of the protection layer can be certainly reduced without deteriorating the characteristics of the magnetic head element. It is preferred that the processing step includes chamfering a corner edge of the protection layer between a first end surface near which the inductive write head elements are formed and the bottom surface to form a chamfered section so that a distance from the end edge of the pair of magnetic poles to the edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm. Thus, the bottom surface of the bar member is smoothly continued to the chamfered section surface and also the corner edge of the bar member itself is chamfered. Therefore, it is possible to reduce generation of chipping of the corner edge during the manufacturing process after the chamfering and to reduce possibility of a crash of the magnetic head slider with the disk surface to improve the reliability. It is also preferred that the processing step includes chamfering the corner edge to form the chamfered section with an angle in a range of 20 to 70 degrees with respect to the bottom surface. If the angle is in this range, airflow vortexes formed at the air-outlet of the slider in operation become small and thus contaminations or particles caught therein can be reduced. It is preferred that the processing step includes etching the bottom surface so that a distance from the end edge of the pair of magnetic poles to the edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm. It is further preferred that the lapping step includes lapping the bottom surface of the bar member using diamond abrasive grains. Preferably, the providing step includes providing a substrate with a plurality of magnetoresistive effect (MR) read head elements, with a plurality of inductive write head elements, each inductive write head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering the plurality of MR read head elements and the plurality of inductive write head elements. According to the present invention, also, a manufacturing method of a flying magnetic head slider includes a step of providing a substrate with a plurality of inductive write head elements formed thereon, each head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer made of a resist material, covering the plurality of inductive write head elements, the protection layer on an end edge of the pair of magnetic poles having a thickness in a range of 10 to 15 μm, a step of cutting the substrate to separate into a plurality of bar members, each of the bar members having aligned inductive write head elements, a step of etching a bottom surface of each bar member, and a step of cutting each bar member to separate into a plurality of individual magnetic head sliders. The protection layer made of the resist material is formed to have a thickness in a range of 10 to 15 μm at an end edge of the pair of magnetic poles, and then the bottom surface of the bar member is etched. Thus, the corner edge of the protection layer is rounded off or more shaved. The rounded edge is produced because the outer region of the lapped surface is shaved greater than its inner region depending upon the lapping direction, the lapping pressure and the abrasive plate material. Because the corner edge is formed to have a curved cross sectional profile, the end edge of the bottom surface to be near to the upper magnetic pole of the inductive write head element, so as to back off the surface of the protection layer. Therefore, it is possible to reduce the amount of the thermal expansion protrusion of the protection layer toward the ABS due to write current during writing operations. Particularly, according to the present invention, because the end edge of the bottom surface is inherently rounded by merely performing the lapping, the manufacturing process becomes quite easy. Also, since this method will induce no damage to the magnetic pole, the thermal expansion protrusion of the protection layer can be certainly reduced without deteriorating the characteristics of the magnetic head element. It is preferred that the etching step includes ion-milling the bottom surface of the bar member. Preferably, the providing step includes providing a substrate with a plurality of MR read head elements, with a plurality of inductive write head elements, each inductive write head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering the plurality of MR read head elements and the plurality of inductive write head elements. Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is an oblique view illustrating a flying magnetic head slider as a preferred embodiment according to the present invention; FIG. 2 is an axial section view illustrating the magnetic head slider of the embodiment shown in FIG. 1; FIG. 3 is a flow chart illustrating a part of a manufacturing process of the magnetic head slider of the embodiment shown in FIG. 1; FIGS. 4a, 4b and 4c are enlarged axial section views illustrating corner edges between trailing surfaces and ABSs of the bar member in the respective processes in the embodiment shown in FIG. 1; FIG. 5 is a flow chart illustrating a part of a manufacturing process of a magnetic head slider in another embodiment according to the present invention; and FIG. 6 is a flow chart illustrating a part of a manufacturing process of a magnetic head slider in further embodiment according to the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 illustrates a flying magnetic head slider as a preferred embodiment according to the present invention, and FIG. 2 illustrates an axial section of the magnetic head slider of this embodiment. As shown in these figures, a magnetic head slider 10 substantially consists of a substrate section 11 made of for example Al2O3-TiC, thin-film magnetic head elements 12 such as a magnetoresistive effect read head element 12a and an inductive write head element 12b formed on a rear surface (element formed surface) of the substrate section 11, a protection layer 13 made of for example alumina (Al2O3) for covering the magnetic head elements 12, terminal electrodes 14 electrically connected to the magnetic head elements 12, exposed from the protection layer 13, a plurality of rails 15 formed on a bottom surface of the substrate section 11, and ABSs 16 formed on the respective rails 15. In this embodiment, a corner edge between a trailing surface 10a and the bottom surface of the slider is chamfered to form a chamfered section 17. A corner edge 18 between this chamfered section 17 and the bottom surface is rounded by lapping to have a curved cross sectional profile. A distance T between the corner edge 18 before rounding namely just after chamfering and an upper end edge of an upper magnetic pole 12c of the inductive write head element is desirably determined in a range of 1-15 μm. It is desired that an angle θ of a surface of the chamfered section 17 with respect to the bottom surface be in a range of 20-70 degrees. If this angle between the chamfered section surface and the bottom surface is too small, edge control in the chamfering becomes difficult. Whereas if the angle is too large, the magnetic pole, yoke and also coil of the inductive write head element 12b may be removed. When the angle is in this range, airflow vortexes formed at the air-outlet of the slider in operation become small and thus contaminations or particles caught therein can be reduced. The surface of the chamfered section 17 is not necessary to be completely flat but some surface asperities may be permitted. If there are surface asperities, an average angle between the surface of the chamfered section 17 and the bottom surface should be in the above-mentioned range. FIG. 3 illustrates a part of a manufacturing process of the magnetic head slider of this embodiment, and FIGS. 4a, 4b and 4c illustrate enlarged axial section of corner edge portions between trailing surfaces and bottom surfaces of the magnetic head slider in the respective processes in this embodiment. Hereinafter, the manufacturing method of the magnetic head slider of this embodiment will be described using this drawing as reference. First, a wafer or substrate made of Al2O3-TiC for example is prepared (Step S1). Then, many thin-film magnetic head elements consisting of MR read head elements and inductive write head elements, many terminal electrodes for the respective thin-film magnetic head elements, and a protection layer are formed on the wafer by using a known thin-film integration technique (Step S2). Thus, a wafer with a thin-film surface layer of the magnetic head elements and the protection layer made of for example alumina (Al2O3) for over-coating the magnetic head elements is obtained. Then, the wafer is cut to separate into a plurality of bar members each of which has a plurality of aligned magnetic head elements (Step S3). Then, a bottom surface of each bar member, which surface will configure ABSs is lapped to adjust an MR height and to form the ABSs (Step S4). FIG. 4a illustrates a corner edge portion between a top surface that will configure the trailing surface 10a of the magnetic head slider and the bottom surface or ABS side surface of the bar member in this state. Then, the protection layer 17 at a corner edge between the bottom surface 10b and the top surface 10a of each bar member, which top surface will configure the trailing surface of each magnetic head slider is chamfered to form a chamfered surface 17 (Step S5). FIG. 4b illustrates the corner edge portion of the bar member in this state. This chamfering may be performed by lapping, grinding, dry etching or chemical etching. In this case, a distance T between the corner edge and the upper end edge of the upper magnetic pole of the inductive write head element is determined in a range of 1-15 μm. Also, the chamfering should be executed so that an angle θ of the chamfered section surface 17 with respect to the bottom surface becomes in a range of 20-70 degrees. If this angle between the chamfered section surface and the bottom surface is too small, edge control in the chamfering becomes difficult. Whereas if the angle is too large, the magnetic pole, yoke and also coil of the inductive write head element 12b may be removed. When the angle is in this range, airflow vortexes formed at the air-outlet of the slider in operation become small and thus contaminations or particles caught therein can be reduced. The chamfered section surface is not necessary to be completely flat but some surface asperities may be permitted. If there are surface asperities, an average angle between the chamfered section surface and the bottom surface should be in the above-mentioned range. Then, the bottom surface 10b of each bar member, which surface will configure the ABSs, is finally lapped (Step S6) by using diamond abrasive grain. In general, when the bottom surface is finally lapped, the corner edge 18 of the protection layer 13 will be rounded off or more shaved. The rounded edge is produced because the outer region of the lapped surface is shaved greater than its inner region depending upon the lapping direction, the lapping pressure and the abrasive plate material. A depth Z and a width X of the rounded edge of an alumina layer are Z=1.53 nm and X=5-12 μm, when the alumina layer surface is lapped using diamond abrasive grains with a nominal diameter of {fraction (1/10)} μm and a tin lapping plate under conditions of an applied load of 2.6 kg/cm3 and a lapping plate rotating speed of 2 rpm. FIG. 4c illustrates the corner edge portion of the bar member in this state. As will be apparent from the figure, by performing the final lapping, a corner edge portion 18 with a curved cross sectional profile is formed. This causes the end edge of the bottom surface 10b to be near to the upper magnetic pole 12c of the inductive write head element 12b, so as to back off the surface of the protection layer 13. Therefore, it is possible to reduce the amount of the thermal expansion protrusion of the protection layer 13 toward the ABS due to write current during writing operations. Particularly, according to this method, because the end edge of the bottom surface is inherently rounded by merely performing the final lapping, the manufacturing process becomes quite easy. Also, since this method will induce no damage to the magnetic pole, the thermal expansion protrusion of the protection layer can be certainly reduced without deteriorating the characteristics of the magnetic head element. Thereafter, the bottom surfaces of the plurality of bar members are etched by ion milling for example to form a rail pattern (Step S7). Then, each bar member is cut to separate into individual magnetic head sliders (Step S8). Actually, bar member samples were fabricated. Namely, in chamfering process at Step S5, the corner edge between the bottom surface and the top surface of the bar member sample was chamfered to form a chamfered surface with an angle θ of 45 degrees with respect to the bottom surface and with a distance T of 15 μm between the corner edge 18 and the upper end edge of the upper magnetic pole 12c of the inductive write head element. Then, in final lapping process at Step S6, the bottom surface of the bar member sample provided with the chamfered section was lapped. After the final lapping, a first depth at the corner edge 18 from the ABS level and a second depth (pole tip recess, PTR) at the top of the upper pole 12c from the ABS level were measured. The measured first and second depths were 4.3 nm and 2.1 nm, respectively. Corresponding depths in a bar member sample with no chamfered surface but only the final lapping being performed were 1.8 nm and 2.2 nm, respectively. Therefore, it was confirmed that according to the manufacturing process of this embodiment the protection layer 13 only at a region having a little effect on the performance of the magnetic head element can be dented about 2 nm without inducing any damage on the PTR that will exert a great influence upon the actual characteristics of the magnetic head element. Then, thus fabricated magnetic head slider was mounted on a magnetic disk drive apparatus and a probability of contact of the magnetic head slider with the rotating magnetic disk surface when a write current was flowing through the inductive write head element was measured. The measured probability of the magnetic head slider according to this embodiment was about half of that of the conventional magnetic head slider. In addition, according to the embodiment, because the chamfered section 17 is formed at the corner edge between the bottom surface and the trailing surface 10a of the magnetic head slider, there is no place for catching contaminations or particles near this edge and thus it is possible to prevent depositions of contaminations and unnecessary particles. Also, the chamfered corner edge of the magnetic head slider will reduce generation of chipping of the corner edge during the manufacturing process after the chamfering and will reduce possibility of a crash of the head slider with the disk surface to improve the reliability. FIG. 5 illustrates a part of a manufacturing process of the magnetic head slider as another embodiment according to the present invention. In this embodiment, a thickness in a partial area of a protection layer between an upper end edge of an upper magnetic pole and a corner edge between a bottom surface and a top surface of a bar member is adjusted in a range of 1-15 μm without performing chamfering. Hereinafter, the manufacturing method of the magnetic head slider of this embodiment will be described using this drawing as reference. First, a wafer or substrate made of Al2O3-TiC for example is prepared (Step S11). Then, many thin-film magnetic head elements consisting of MR read head elements and inductive write head elements, many terminal electrodes for the respective thin-film magnetic head elements, and a protection layer are formed on the wafer by using a known thin-film integration technique (Step S12). Thus, a wafer with a thin-film surface layer of the magnetic head elements and the protection layer made of for example alumina (Al2O3) for over-coating the magnetic head elements is obtained. Then, the wafer is cut to separate into a plurality of bar members each of which has a plurality of aligned magnetic head elements (Step S13). Then, a bottom surface of each bar member, which surface will configure ABSs, is lapped to adjust an MR height and to form the ABSs (Step S14). Then, the bottom surface of the protection layer of each bar member is etched by dry etching or wet etching to adjust the thickness in a partial area of the protection layer so that the distance T from the upper end edge of the upper magnetic pole to the corner edge between the bottom surface and the top surface of the bar member is in a range of 1-15 μm (Step S15). Then, the bottom surface of each bar member, which surface will configure the ABSs, is finally lapped (Step S16) by using diamond abrasive grain. In general, when the bottom surface is finally lapped, the corner edge of the protection layer will be rounded off or more shaved. The rounded edge is produced because the outer region of the lapped surface is shaved greater than its inner region depending upon the lapping direction, the lapping pressure and the abrasive plate material. By performing the final lapping, a corner edge portion with a curved cross sectional profile is formed. This causes the end edge of the bottom surface to be near to the upper magnetic pole of the inductive write head element, so as to back off the surface of the protection layer. Therefore, it is possible to reduce the amount of the thermal expansion protrusion of the protection layer toward the ABS due to write current during writing operations. Particularly, according to this method, because the end edge of the bottom surface is inherently rounded by merely performing the final lapping, the manufacturing process becomes quite easy. Also, since this method will induce no damage to the magnetic pole, the thermal expansion protrusion of the protection layer can be certainly reduced without deteriorating the characteristics of the magnetic head element. Thereafter, the bottom surfaces of the plurality of bar members are etched by ion milling for example to form a rail pattern (Step S17). Then, each bar member is cut to separate into individual magnetic head sliders (Step S18). FIG. 6 illustrates a part of a manufacturing process of the magnetic head slider as further embodiment according to the present invention. In this embodiment, a thickness in at least partial area of a protection layer from an upper end edge of an upper magnetic pole to a corner edge between a bottom surface and a top surface of a bar member is determined in a range of 10-15 μm, and then etching is performed without executing chamfering and final lapping. Hereinafter, the manufacturing method of the magnetic head slider of this embodiment will be described using this drawing as reference. First, a wafer or substrate made of Al2O3-TiC for example is prepared (Step S21). Then, many thin-film magnetic head elements consisting of MR read head elements and inductive write head elements, many terminal electrodes for the respective thin-film magnetic head elements, and a protection layer are formed on the wafer by using a known thin-film integration technique (Step S22). Thus, a wafer with a thin-film surface layer of the magnetic head elements and the protection layer made of a resist material for over-coating the magnetic head elements is obtained. The thickness of the protection layer on the upper end edge of the upper magnetic pole is determined in a range of 10-15 μm. Then, the wafer is cut to separate into a plurality of bar members each of which has a plurality of aligned magnetic head elements (Step S23). Then, a bottom surface of each bar member, which surface will configure ABSs is lapped to adjust an MR height and to form the ABSs (Step S24). Then, the bottom surface of the protection layer of each bar member is etched by dry etching or ion milling (Step S25). If the bottom surface is ion-milled, the corner edge of the protection layer will be rounded off or more shaved. In other words, by performing the ion milling, a corner edge portion with a curved cross sectional profile is formed. This causes the end edge of the bottom surface to be near to the upper magnetic pole of the inductive write head element, so as to back off the surface of the protection layer. Therefore, it is possible to reduce the amount of the thermal expansion protrusion of the protection layer toward the ABS due to write current during writing operations. Particularly, according to this method, because the end edge of the bottom surface is inherently rounded by merely performing the ion milling, the manufacturing process becomes quite easy. Also, since this method will induce no damage to the magnetic pole, the thermal expansion protrusion of the protection layer can be certainly reduced without deteriorating the characteristics of the magnetic head element. Thereafter, the bottom surfaces of the plurality of bar members are etched by ion milling for example to form a rail pattern (Step S26). Then, each bar member is cut to separate into individual magnetic head sliders (Step S27). Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a manufacturing method of a flying magnetic head slider provided with a thin-film magnetic head element. 2. Description of the Related Art In a magnetic disk drive device, thin-film magnetic head elements for writing magnetic information into and/or reading magnetic information from magnetic disks are in general formed on magnetic head sliders flying in operation above the rotating magnetic disks. The sliders are supported at top end sections of suspensions, respectively. Recently, a flying height of the magnetic head slider rapidly lowers to satisfy the requirement for ever increasing data storage capacities and densities in today's magnetic disk drive apparatus. Because of such lowered flying height, a possible protrusion of a protection layer of the slider at a corner portion between an air bearing surface (ABS) and a trailing surface, which corner is the lowest portion of the slider during the flying operations has not become negligible. Particularly, in the magnetic head slider with an inductive write head element, a protection layer may thermally expand and protrude due to the write current causing the protruded portion to come into contact with the magnetic disk surface during operations. Known is a method of forming a step or recess at a corner edge between the ABS and the trailing surface of the magnetic head slider, by partially removing the protection layer during a patterning process of the ABS, to reduce the protrusion of the protection layer as small amount as possible. In another known method disclosed for example in U.S. Pat. No. 6,428,715 B1, protrusion of a protection or overcoat layer made of a typical material of alumina (Al 2 O 3 ) is reduced by immersing the overcoat layer in an alkaline solution and thus by etching the whole ABS of the overcoat layer to form a step. However, according to the former known method, due to the limited resolution of a resist and the limited precision in an exposure equipment used for patterning the ABS, it is impossible to bring a starting point of the step close to a magnetic pole of the inductive write head element. Therefore, the protrusion amount cannot be reduced so much. If the step is formed over a part of the magnetic pole, a coating film such as a diamond like carbon (DLC) film is removed causing corrosion of the pole to occur. According to the latter known method, it is ensured to etch the alumina and to form a step. However, if the magnetic pole contains a metal material easily etched by an alkaline, the pole itself is etched to deteriorate the characteristics of the write head element. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>It is therefore an object of the present invention to provide a manufacturing method of a flying magnetic head slider, whereby manufacturing process becomes easy. Another object of the present invention is to provide a manufacturing method of a flying magnetic head slider, whereby protrusion of a protection layer can be reduced without adversely affecting head element characteristics. According to the present invention, a manufacturing method of a flying magnetic head slider includes a step of providing a substrate with a plurality of inductive write head elements formed thereon, each head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering the plurality of inductive write head elements, a step of cutting the substrate to separate into a plurality of bar members, each of the bar members having aligned inductive write head elements, a step of processing the protection layer of each bar member so that a distance from an end edge of the pair of magnetic poles to an edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm, a step of lapping each bottom surface of the bar member, and cutting each bar member to separate into a plurality of individual magnetic head sliders. After shortening the distance from an end edge of the pair of magnetic poles to an edge of the bottom surface of the bar member becomes in a range of 1 to 15 μm, the bottom surface of the bar member is lapped. Thus, the corner edge of the protection layer is rounded off or more shaved. The rounded edge is produced because the outer region of the lapped surface is shaved greater than its inner region depending upon the lapping direction, the lapping pressure and the abrasive plate material. Because the corner edge is formed to have a curved cross sectional profile, the end edge of the bottom surface to be near to the upper magnetic pole of the inductive write head element, so as to back off the surface of the protection layer. Therefore, it is possible to reduce the amount of the thermal expansion protrusion of the protection layer toward the ABS due to write current during writing operations. Particularly, according to the present invention, because the end edge of the bottom surface is inherently rounded by merely performing the lapping, the manufacturing process becomes quite easy. Also, since this method will induce no damage to the magnetic pole, the thermal expansion protrusion of the protection layer can be certainly reduced without deteriorating the characteristics of the magnetic head element. It is preferred that the processing step includes chamfering a corner edge of the protection layer between a first end surface near which the inductive write head elements are formed and the bottom surface to form a chamfered section so that a distance from the end edge of the pair of magnetic poles to the edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm. Thus, the bottom surface of the bar member is smoothly continued to the chamfered section surface and also the corner edge of the bar member itself is chamfered. Therefore, it is possible to reduce generation of chipping of the corner edge during the manufacturing process after the chamfering and to reduce possibility of a crash of the magnetic head slider with the disk surface to improve the reliability. It is also preferred that the processing step includes chamfering the corner edge to form the chamfered section with an angle in a range of 20 to 70 degrees with respect to the bottom surface. If the angle is in this range, airflow vortexes formed at the air-outlet of the slider in operation become small and thus contaminations or particles caught therein can be reduced. It is preferred that the processing step includes etching the bottom surface so that a distance from the end edge of the pair of magnetic poles to the edge of a bottom surface of the bar member becomes in a range of 1 to 15 μm. It is further preferred that the lapping step includes lapping the bottom surface of the bar member using diamond abrasive grains. Preferably, the providing step includes providing a substrate with a plurality of magnetoresistive effect (MR) read head elements, with a plurality of inductive write head elements, each inductive write head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering the plurality of MR read head elements and the plurality of inductive write head elements. According to the present invention, also, a manufacturing method of a flying magnetic head slider includes a step of providing a substrate with a plurality of inductive write head elements formed thereon, each head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer made of a resist material, covering the plurality of inductive write head elements, the protection layer on an end edge of the pair of magnetic poles having a thickness in a range of 10 to 15 μm, a step of cutting the substrate to separate into a plurality of bar members, each of the bar members having aligned inductive write head elements, a step of etching a bottom surface of each bar member, and a step of cutting each bar member to separate into a plurality of individual magnetic head sliders. The protection layer made of the resist material is formed to have a thickness in a range of 10 to 15 μm at an end edge of the pair of magnetic poles, and then the bottom surface of the bar member is etched. Thus, the corner edge of the protection layer is rounded off or more shaved. The rounded edge is produced because the outer region of the lapped surface is shaved greater than its inner region depending upon the lapping direction, the lapping pressure and the abrasive plate material. Because the corner edge is formed to have a curved cross sectional profile, the end edge of the bottom surface to be near to the upper magnetic pole of the inductive write head element, so as to back off the surface of the protection layer. Therefore, it is possible to reduce the amount of the thermal expansion protrusion of the protection layer toward the ABS due to write current during writing operations. Particularly, according to the present invention, because the end edge of the bottom surface is inherently rounded by merely performing the lapping, the manufacturing process becomes quite easy. Also, since this method will induce no damage to the magnetic pole, the thermal expansion protrusion of the protection layer can be certainly reduced without deteriorating the characteristics of the magnetic head element. It is preferred that the etching step includes ion-milling the bottom surface of the bar member. Preferably, the providing step includes providing a substrate with a plurality of MR read head elements, with a plurality of inductive write head elements, each inductive write head element having a pair of magnetic poles facing to each other via a magnetic gap, and with a protection layer covering the plurality of MR read head elements and the plurality of inductive write head elements. Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings. | 20040708 | 20071016 | 20050113 | 72456.0 | 0 | KIM, PAUL D | MANUFACTURING METHOD OF FLYING MAGNETIC HEAD SLIDER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,885,764 | ACCEPTED | Adjustable optical apparatus adapter | An adjustable optical apparatus adapter is disclosed to include a camera platform provided with a mounting screw and a wing nut for securing a camera to the camera platform, a telescope holder for holding a telescope, a holding down frame controlled by a lock screw to hold down a telescope in the telescope holder, and a camera platform lock mounted in the a horizontal sliding slot in camera platform and a vertical sliding slot in telescope holder for locking the camera platform to the telescope holder after position adjustment of the camera platform horizontally and vertically relative to the telescope holder to have the loaded telescope at the telescope holder in axial alignment with the loaded camera at the camera platform. | 1. An adjustable optical apparatus adapter, comprising: a camera platform adapted to carry a camera, comprising a fastening screw member adapted to affix a camera to said camera platform, and at least one horizontal sliding slot; a telescope holder adapted to hold a telescope, having an upper part forming a holder frame and a lower part defining a vertical sliding slot, said holder frame having at least one screw hole vertically extended in a top side thereof; a lock screw threaded into the screw hole of said holder frame and adapted to lock a telescope to said holder frame; and a camera platform lock mounted in the at least one horizontal sliding slot of said camera platform and the vertical sliding slot of said telescope holder for enabling said camera platform to be moved vertically relative to said telescope holder along said vertical sliding slot and said telescope holder to be moved horizontally relative to said camera holder along said at least one horizontal sliding slot and adapted to lock said camera platform to said telescope holder. 2. The adjustable optical apparatus adapter as claimed in claim 1, wherein said camera platform lock comprises: a base block, comprising a polygonal shoulder inserted into said at least one horizontal sliding slot of said camera platform for enabling said base block to be moved along said at least one horizontal sliding slot and for stopping said base block from rotary motion relative to said camera platform, and a screw rod forwardly extended from said polygonal shoulder and inserted through said vertical sliding slot of said telescope holder; and a fastening member threaded onto the screw rod of said base block and adapted to affix said camera platform to said telescope holder. 3. The adjustable optical apparatus adapter as claimed in claim 2, wherein said camera lock further comprises a screw hole axially formed in the screw rod of said base block, a screw fastened to the screw hole in the screw rod of said base block to secure said fastening member to the screw rod of said base block, a slide mounted on the screw rod of said base block between said telescope holder and said fastening member and adapted to guide movement of said base block along said vertical sliding slot of said telescope holder, and an ornamental cap capped on said fastening member. 4. The adjustable optical apparatus adapter as claimed in claim 3, wherein said telescope holder comprises at least one vertical sliding groove arranged in parallel to said vertical sliding slot; said slide comprises a polygonal center opening coupled to said polygonal shoulder of said base block, and at least one vertical coupling flange respectively coupled to the at least one vertical sliding groove of said telescope holder for guiding movement of said base block along the vertical sliding slot of said telescope holder. 5. The adjustable optical apparatus adapter as claimed in claim 2, wherein said camera platform comprises at least one horizontal sliding groove; said base block of said camera lock comprises at least one horizontal coupling flange respectively coupled to the at least one horizontal sliding groove to guide movement of said base block along said at least one sliding slot of said camera platform. 6. The adjustable optical apparatus adapter as claimed in claim 1, wherein said telescope holder further comprises a holding down frame fastened to said lock screw and suspended inside said holder frame and vertically movably controlled by said lock screw to hold down a telescope in said frame holder. 7. The adjustable optical apparatus adapter as claimed in claim 6, wherein said lock screw has a locating groove extended around the periphery of a front end thereof; said holding down frame comprises a top mounting hole, which receives the front end of said lock screw, a front screw hole perpendicularly extended from said top mounting hole to a front side thereof, and a tightening up screw threaded into the front screw hole of said holding down frame and engaged into the locating groove of said lock screw to affix said holding down frame to said lock screw. 8. The adjustable optical apparatus adapter as claimed in claim 6, further comprising a plurality of anti-skid pads respectively fastened to an inner bottom wall of said holder frame and a bottom wall of said holding down frame for holding down a telescope in between said holder frame and said holding down frame. 9. The adjustable optical apparatus adapter as claimed in claim 6, wherein said holder frame comprises at least one vertically extended sliding rail; said holder frame comprises at least one vertically extended coupling groove respectively coupled to said at least one vertically extended sliding rail of said holder frame to guide vertical movement of said holding down frame within said holder frame. 10. The adjustable optical apparatus adapter as claimed in claim 1, wherein said camera platform further comprises a wing nut threaded onto said fastening screw member and stopped between said fastening screw member and a bottom wall of said camera platform. 11. The adjustable optical apparatus adapter as claimed in claim 2, wherein said camera platform further comprises a horizontally extended insertion hole; said camera platform lock further comprises a horizontal screw hole formed in said base block and extended through two opposite sides of said base block, and a horizontal adjustment screw inserted through the horizontal insertion hole of said camera platform and threaded into the horizontal screw hole in said base block for rotation by the user to move said base block horizontally along said at least one horizontal sliding slot of said camera platform. 12. The adjustable optical apparatus adapter as claimed in claim 11, wherein said telescope holder further comprises a vertically extended insertion hole in the lower part thereof; said camera platform lock further comprises a vertical screw hole formed in said base block and extended through top and bottom sides of said base block, and a vertical adjustment screw inserted through the vertically extended insertion hole in the lower part of said telescope holder and threaded into the vertical screw in said base block for rotation by the user to move said base block vertically along said vertical sliding slot of said telescope holder. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical apparatus adapter for coupling a telescope to a camera, and more particularly to an adjustable optical apparatus adapter that can be adjusted horizontally as well as vertically to fit different types and models of telescopes and cameras. 2. Description of Related Art Following prosperity of the society, people pay more attention to recreational life. In consequence, photographic activities have become popular. Due to limited amplification, it is difficult to pick up the image of a remote scene with a camera. In this case, a telescope should be used. When using a camera with a telescope, an adapter is necessary to couple the telescope to the camera, keeping the eyepiece of the telescope in axial alignment with the lens of the camera. FIG. 1A shows a conventional optical apparatus adapter for coupling a telescope to a camera. According to this design, the optical apparatus adapter 10 is shaped like a barrel having an outer thread 11 at one end for fastening to a camera 15 and an inner thread 13 at the other end for fastening to the outer thread 23 around the periphery of the eyepiece of a telescope 20 (see also FIG. 1B). By means of the telescope 20, the image of a remote scene can be mapped onto the image sensor 151 of the camera 15. This design of optical apparatus adapter is functional, however it fits only a particularly designed telescope and a particularly designed camera. A telescope without an outer thread for threading into the inner thread 13 of the optical apparatus adapter or a camera without an inner thread for threading onto the outer thread 11 of the optical apparatus adapter cannot be used with the optical apparatus adapter. SUMMARY OF THE INVENTION The present invention has been accomplished under the circumstances in view. It is therefore one object of the present invention to provide an adjustable optical apparatus adapter, which can be adjusted to couple a telescope to a camera in an axially aligned status. It is anther object of the present invention to provide an adjustable optical apparatus adapter, which can be conveniently adjusted to fit different types and models of telescopes and cameras. It is still another object of the present invention to provide an adjustable optical apparatus adapter, which is easy and inexpensive to manufacture. To achieve these and other objects of the present invention, the adjustable optical apparatus adapter comprises a camera platform adapted to carry a camera, the camera platform comprising a fastening screw member adapted to affix a camera to the camera platform, and at least one horizontal sliding slot; a telescope holder adapted to hold a telescope, the telescope holder having an upper part forming a holder frame and a lower part defining a vertical sliding slot, the holder frame having a screw hole vertically extended in a top side thereof; a lock screw threaded into the screw hole of the holder frame and adapted to lock a telescope to the holder frame; and a camera platform lock mounted in the at least one horizontal sliding slot of the camera platform and the vertical sliding slot of the telescope holder for enabling the camera platform to be moved vertically relative to the telescope holder along the vertical sliding slot and the telescope holder to be moved horizontally relative to the camera holder along the at least one horizontal sliding slot and adapted to lock the camera platform to the telescope holder. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is an elevational view of an optical apparatus adapter according to the prior art. FIG. 1B is an exploded view showing the relative positioning structure between the optical apparatus adapter and the telescope and the camera according to the prior art. FIG. 2A is an adjustable exploded view of an optical apparatus adapter according to the present invention. FIG. 2B is a perspective assembly view in an enlarged scale of the adjustable optical apparatus adapter shown in FIG. 2A. FIG. 3A is an applied view of the present invention, showing a telescope and a camera installed in the adjustable optical apparatus adapter according to the present invention. FIG. 3B is a side view of FIG. 3A. FIG. 4A is a schematic front view of the present invention. FIG. 4B is similar to FIG. 4A but showing the relative position between the camera platform and the telescope holder adjusted. FIG. 5A is a schematic side view showing another application example of the present invention. FIG. 5B is a schematic side view showing still another application example of the present invention. FIG. 6A is an exploded view of an alternate form of the adjustable optical apparatus adapter according to the present invention. FIG. 6B is an assembly view in an enlarged scale of FIG. 6A. FIG. 6C-6E show the assembly views of the combination by optical apparatus and the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 2A, 2B, 3A, and 3B, an adjustable optical apparatus adapter in accordance with one embodiment of the present invention is shown comprised of a camera platform 30, a telescope holder 40, a holding down frame 50, and a camera platform lock 60. The camera platform 30 comprises at least one vertical slot 31 cut through the top and bottom walls thereof, a horizontal sliding slot 33 in one vertical sidewall thereof, and two horizontal sliding grooves 35 arranged in parallel at two sides along the horizontal sliding slot 33. Further, a mounting screw 311 is threaded into a wind nut 313 and inserted through the at last one vertical slot 31 to fix a photographic apparatus, for example, a camera 83 to the camera platform 30. The telescope holder 40 has an upper part 41 and a lower part 43. The upper part 41 comprises a holder frame 410, a top screw hole 411 vertically formed in the top side of the holder frame 410, and at least one, for example, two coupling rails 413 formed integral with the inside wall of the holder frame 410 at two sides. The lower part 43 comprises a vertical sliding slot 433, two vertical sliding grooves 435 arranged in parallel at two sides of the vertical sliding slot 433, a bottom mounting plate 439, and a screw hole 437 vertically formed in the bottom mounting plate 439. The holding down frame 50 comprises a top mounting hole 51, at least one, for example, two coupling grooves 53 symmetrically disposed at two opposite lateral sides corresponding to the coupling rails 413 of the telescope holder 40, and a front screw hole 555 in communication with the top mounting hole 51. The camera platform lock 60 is comprised of a base block 61, a slide 63, and a locknut 65. The base block 61 comprises at least one, for example, two horizontal coupling flanges 615 arranged in parallel at the front side and respectively coupled to the horizontal sliding grooves 35 of the camera platform 30, a rectangular shoulder 613 forwardly extended from the front side and inserted into the horizontal sliding slot 33 of the camera platform 30, a front screw rod 611 axially forwardly extended from the rectangular shoulder 613 and inserted through the vertical sliding slot 433 of the telescope holder 40, and a screw hole 617 axially formed in the front end of the front screw rod 611. The slide 63 has a center opening 633 fitting the cross section of the rectangular shoulder 613 of the base block 61, and two coupling flanges 635 arranged in parallel at two sides of the center opening 633 and respectively coupled to the vertical sliding grooves 435 of the telescope holder 40. The locknut 65 is threaded onto the front screw rod 611 to lock the camera platform 30 to the telescope holder 40 at the desired elevation. After installation of the a mounting screw 311 in one vertical slot 31 of the camera platform 30 to fix a camera 83 to the camera platform 30, the user can turn the wind nut 313 to lock/unlock the camera 83. Further, the user can move the mounting screw 311 in the at least one vertical slot 31 to the desired location subject to the model of the photographic apparatus to be used. Therefore, the camera platform 30 can hold any of a variety of cameras. After coupling of the coupling grooves 53 of the holding down frame 50 to the coupling rails 413 of the telescope holder 40, a holding down frame 50 define with the holder frame 410 a clamping hole 55 for holding down a telescope 80. A lock screw 57 is provided to move the holding down frame 50 in the telescope holder 40, and to further adjust the size of the clamping hole 55 so as to lock/unlock the telescope 80. The lock screw 57 has a threaded shank 573 threaded into the top screw hole 411 of the holder frame 410 of the telescope holder 40 and inserted into the top mounting hole 51 of the holding down frame 50, and a locating groove 571 extended around the periphery of the front end of the threaded shank 573. A tightening up screw 551 is threaded into the front screw hole 555 of the holding down frame 50 and engaged into the locating groove 571 to fix the holding down frame 50 to the lock screw 57. When rotating the lock screw 57 forwards or backwards in the top screw hole 411 of the holder frame 410, the holding down frame 50 is moved vertically upwards or downwards with the lock screw 57 along the coupling rails 413 of the telescope holder 40 to adjust the size of the clamping hole 55 subject to the size of the telescope 80. Therefore, the telescope holder 40 can hold any of a variety of telescopes. Rubber pads 70 are respectively provided at the bottom wall 59 of the holding down frame 50 and the inner bottom wall 419 of the holder frame 410 to protect the telescope 80 and to prevent slipping of the telescope 80. The aforesaid camera platform lock 60 further comprises a screw 67, a washer 68, and an ornamental cap 69. The screw 67 is inserted through the washer 68 and then threaded into the screw hole 617 of the base block 61 to prevent falling of the lock nut 65 from the base block 61. The ornamental cap 69 is capped on the lock nut 65 to keep the screw 67 and the washer 68 from sight. The ornamental cap 69 may be marked with a company's logo or the like. Further, by means of the screw hole 437, the bottom mounting plate 439 of the telescope holder 40 can be fastened to the camera platform of a tripod (not shown). After installation of the telescope holder 40 in a tripod, a telescope 80 can be fastened to the telescope holder 40 and firmly held down by the holding down frame 50, and a camera 83 can be affixed to the camera platform 30, keeping the lens of the camera 83 aimed at the eyepiece of the telescope 80. Referring to FIGS. 4A and 4B and FIG. 2A again, the rectangular shoulder 613 of the base block 61 fits the horizontal sliding slot 33 of the camera platform 30. Therefore, the base block 61 is prohibited from rotary motion in the horizontal sliding slot 33 of the camera platform 30 but can be moved along the horizontal sliding slot 33 of the camera platform 30 to adjust the relative position between the camera 83 at the camera platform 30 and the telescope 80 at the telescope holder 40 horizontally and moved along the vertical sliding slot 433 of the telescope holder 40 to adjust the relative position between the camera 83 at the camera platform 30 and the telescope 80 at the telescope holder 40 vertically, keeping the lens of the camera 83 in axial alignment with the eyepiece of the telescope 80. Referring to FIGS. 5A and 5B, the telescope holder 40 can hold any of a variety of different models of telescopes, for example, the telescope 81 shown in FIG. 5A or the telescope 83 shown in FIG. 5B, or a periscope (not shown). FIGS. 6A to 6E show an alternate form of the present invention. According to this embodiment, the base block 61 has a horizontally extended screw hole 911 and a vertically extended screw hole 933; the camera platform 30 has a horizontally extended insertion hole 441; the telescope holder 40 has a vertically extended insertion hole 45 in the lower part 43; a horizontal adjustment screw 91 is inserted through the horizontally extended insertion hole 441 and threaded into the horizontally extended screw hole 911 of the base block 61 and a vertical adjustment screw 93 is inserted through the vertically extended insertion hole 45 and threaded into the vertically extended screw hole 933 of the base block 61; a horizontal adjustment member 951 is fastened to the horizontal adjustment screw 91 for rotating the horizontal adjustment screw 91 to move the base block 61 horizontally relative to the camera platform 30; a vertical adjustment member 952 is fastened to the vertical adjustment screw 93 for rotating the vertical adjustment screw 93 to move the base block 61 vertically relative to the telescope holder 40. Further, the bottom mounting plate 439 may be eliminated, and the screw hole 437 may be directly formed in the bottom side of the lower part 43 of the telescope holder 40. Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to an optical apparatus adapter for coupling a telescope to a camera, and more particularly to an adjustable optical apparatus adapter that can be adjusted horizontally as well as vertically to fit different types and models of telescopes and cameras. 2. Description of Related Art Following prosperity of the society, people pay more attention to recreational life. In consequence, photographic activities have become popular. Due to limited amplification, it is difficult to pick up the image of a remote scene with a camera. In this case, a telescope should be used. When using a camera with a telescope, an adapter is necessary to couple the telescope to the camera, keeping the eyepiece of the telescope in axial alignment with the lens of the camera. FIG. 1A shows a conventional optical apparatus adapter for coupling a telescope to a camera. According to this design, the optical apparatus adapter 10 is shaped like a barrel having an outer thread 11 at one end for fastening to a camera 15 and an inner thread 13 at the other end for fastening to the outer thread 23 around the periphery of the eyepiece of a telescope 20 (see also FIG. 1B ). By means of the telescope 20 , the image of a remote scene can be mapped onto the image sensor 151 of the camera 15 . This design of optical apparatus adapter is functional, however it fits only a particularly designed telescope and a particularly designed camera. A telescope without an outer thread for threading into the inner thread 13 of the optical apparatus adapter or a camera without an inner thread for threading onto the outer thread 11 of the optical apparatus adapter cannot be used with the optical apparatus adapter. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been accomplished under the circumstances in view. It is therefore one object of the present invention to provide an adjustable optical apparatus adapter, which can be adjusted to couple a telescope to a camera in an axially aligned status. It is anther object of the present invention to provide an adjustable optical apparatus adapter, which can be conveniently adjusted to fit different types and models of telescopes and cameras. It is still another object of the present invention to provide an adjustable optical apparatus adapter, which is easy and inexpensive to manufacture. To achieve these and other objects of the present invention, the adjustable optical apparatus adapter comprises a camera platform adapted to carry a camera, the camera platform comprising a fastening screw member adapted to affix a camera to the camera platform, and at least one horizontal sliding slot; a telescope holder adapted to hold a telescope, the telescope holder having an upper part forming a holder frame and a lower part defining a vertical sliding slot, the holder frame having a screw hole vertically extended in a top side thereof; a lock screw threaded into the screw hole of the holder frame and adapted to lock a telescope to the holder frame; and a camera platform lock mounted in the at least one horizontal sliding slot of the camera platform and the vertical sliding slot of the telescope holder for enabling the camera platform to be moved vertically relative to the telescope holder along the vertical sliding slot and the telescope holder to be moved horizontally relative to the camera holder along the at least one horizontal sliding slot and adapted to lock the camera platform to the telescope holder. | 20040708 | 20060801 | 20050929 | 68358.0 | 0 | SUTHAR, RISHI S | ADJUSTABLE OPTICAL APPARATUS ADAPTER | SMALL | 0 | ACCEPTED | 2,004 |
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10,885,934 | ACCEPTED | Multi-slot dialog systems and methods | Systems and methods for constructing a series of interactions with a user to collect multiple pieces of related information for the purpose of accomplishing a specific goal or topic (a multi-slot dialog) using a component-based approach are disclosed. The method generally includes outputting a primary header prompt to elicit values for slots in a segment from the user, receiving a primary user response containing a value for each slot in at least a subset of the slots in the segment, processing the primary user response to determine at least one possible recognition value for each slot contained in the primary user response, filling each slot contained in the primary user response with a matched value selected from the corresponding possible recognition values, and repeating the outputting, receiving, processing and filling for any unfilled slots in the segment until all slots in the segment of slots are filled. | 1. A method for constructing and processing a multi-slot dialog with a user, comprising: outputting a primary header prompt to elicit values for slots in a segment from the user; receiving a primary user response, the primary user response containing a value for each slot in at least a subset of the slots in the segment; processing the primary user response to determine at least one possible recognition value for each slot contained in the primary user response; filling each slot contained in the primary user response with a matched value selected from the corresponding at least one possible recognition value; and repeating the outputting, receiving, processing and filling for any unfilled slots in the segment until all slots in the segment of slots are filled. 2. The method of claim 1, further comprising: performing turns to at least one of confirm and clarify the matched slot values for slots contained in the primary user response. 3. The method of claim 2, wherein the at least one of confirm and clarify is selected from the group consisting of silently accept a best match, passively confirm the best match, actively confirm the best match, disambiguate among the best matches, and notify the user of a non-recognition. 4. The method of claim 3, wherein the at least one of confirm and clarify is selected based on the number of possible recognition values for the slots in the primary user response and a corresponding confidence level for each of the possible recognition values. 5. The method of claim 3, wherein when the at least one of confirm and clarify is an active confirmation, the performing turns includes recognizing a user confirmation response as one of a confirmation, a cancellation, and a cancellation and correction, and wherein when the user confirmation response is a cancellation and correction, the correction is processed by processing the correction to determine at least one possible recognition value for each slot contained in the correction. 6. The method of claim 3, wherein when the at least one of confirm and clarify is a passive confirmation, the performing turns includes recognizing a user passive confirmation response as one of a response to a next primary header prompt, a confirmation, a cancellation, and a cancellation and correction, and wherein when the user passive confirmation response is a cancellation and correction, the correction is processed by processing the correction to determine at least one possible recognition value for each slot contained in the correction. 7. The method of claim 1, further comprising: enabling any unfilled slots in the segment of slots, wherein the primary header prompt elicits values for enabled slots in the segment. 8. The method of claim 1, wherein the processing of the primary user response includes applying grammar rules to facilitate recognition of possible values for a corresponding slot. 9. The method of claim 1, wherein the outputting the primary header prompt depends on the set of unfilled segments. 10. The method of claim 1, wherein the outputting and the receiving is one of text-based and speech-based. 11. A system for constructing and processing a multi-slot dialog with a user, comprising: a plurality of slot objects each representing a slot in a segment, each slot capable of being assigned a value based on the multi-slot dialog; at least one slot segment object, each slot segment object containing a corresponding set of slot objects; at least one set of slot group objects for each slot segment object, each slot group object defining parameters associated with a particular combination of slots in the slot segment object; and dialog objects that define a flow of the multi-slot dialog. 12. The system of claim 11, wherein the system is implemented in an object-oriented programming language. 13. The system of claim 11, wherein each parameter for at least one set of slot group objects is classified into one of at least two slot group classes defined to facilitate maintenance of separate sets of the parameters. 14. The system of claim 13, wherein the slot group classes include a pre-recognition slot group class and a post-recognition slot group class. 15. The system of claim 11, wherein each slot object contains grammar to facilitate recognizing a possible value provided by the user for the corresponding slot, rules that facilitate mapping of grammar recognition results to semantic values for the corresponding slot, and variables indicating a state for the corresponding slot. 16. The system of claim 11, wherein the parameters defined by each slot group object is selected from the group consisting of header prompts, help prompts, error prompts, confirmation prompts, disambiguation prompts, and recognition properties. 17. The system of claim 11, wherein the system is one of text-based and speech-based. 18. A method for constructing a multi-slot dialog with a user to obtain multiple items of information over a number of turns, comprising: providing at least one slot segment object, each slot segment object containing a corresponding set of slot objects, each representing a slot in a segment, each slot representing an item of information to be provided by the user; providing at least one set of slot group objects for each slot segment object, each slot group object defining parameters associated with a particular combination of slots in the slot segment object; and executing a multi-slot dialog flow defined by dialog objects. 19. The method of claim 18, wherein each slot object contains grammar to facilitate recognizing a possible value provided by the user for the corresponding slot, rules that map grammar recognition results to semantic values for the corresponding slot, and variables indicating a state for the corresponding slot. 20. The method of claim 18, wherein each parameter for at least one set of slot group objects is classified into one of at least two slot group classes defined to facilitate maintenance of separate sets of the parameters. 21. The method of claim 20, wherein the slot group classes include a pre-recognition slot group class and a post-recognition slot group class. 22. The method of claim 18, wherein the parameters defined by each slot group object is selected from the group consisting of header prompts, help prompts, error prompts, confirmation prompts, disambiguation prompts, and recognition properties. 23. The method of claim 18, wherein the system is one of text-based and speech-based. 24. The method of claim 18, wherein executing includes performing an action in response to a user input, the action being selected from the group consisting of silently accepting a best match, passively confirming the best match, actively confirming the best match, disambiguating among the best matches, and notifying the user of a non-recognition. 25. The method of claim 24, wherein when the action is an active confirmation, the executing further includes recognizing a user confirmation response as one of a confirmation, a cancellation, and a cancellation and correction, and when the user confirmation response is a cancellation and correction, the correction is processed by processing the correction to determine at least one possible recognition value for each slot contained in the correction. 26. The method of claim 24, wherein when the action is a passive confirmation, the executing further includes recognizing a user passive confirmation response as one of a response to a next primary header prompt, a confirmation, a cancellation, and a cancellation and correction, and when the user passive confirmation response is a cancellation and correction, the correction is processed by processing the correction to determine at least one possible recognition value for each slot contained in the correction. 27. The method of claim 24, wherein the action is selected based on a number of possible values for the slots and a corresponding confidence level for each possible value. 28. The method of claim 18, wherein the dialog objects define turns to at least one of confirm and clarify slot values. 29. A computer program product embodied on a computer readable medium, the computer program product including instructions that, when executed by a processor, cause the processor to: output a primary header prompt to elicit values for slots in a segment from the user; receive a primary user response, the primary user response containing a value for each slot in at least a subset of the slots in the segment; process the primary user response to determine at least one possible recognition value for each slot contained in the primary user response; fill each slot contained in the primary user response with a matched value selected from the corresponding at least one possible recognition value; and repeat the outputting, receiving, processing and filling for any unfilled slots in the segment until all slots in the segment of slots are filled. 30. The computer program product of claim 29, further including instructions that, when executed by the processor, cause the processor to: perform turns to at least one of confirm and clarify the matched slot values for slots contained in the primary user response. 31. The computer program product of claim 30, wherein the at least one of confirm and clarify is selected from the group consisting of silently accept a best match, passively confirm the best match, actively confirm the best match, disambiguate among the best matches, and notify the user of a non-recognition. 32. The computer program product of claim 31, wherein the at least one of confirm and clarify is selected based on the number of possible recognition values for the slots in the primary user response and a corresponding confidence level for each of the possible recognition values. 33. The computer program product of claim 31, wherein when the at least one of confirm and clarify is an active confirmation, the performing turns includes recognizing a user confirmation response as one of a confirmation, a cancellation, and a cancellation and correction, and wherein when the user confirmation response is a cancellation and correction, the correction is processed by processing the correction to determine at least one possible recognition value for each slot contained in the correction. 34. The computer program product of claim 31, wherein when the at least one of confirm and clarify is a passive confirmation, the performing turns includes recognizing a user passive confirmation response as one of a response to a next primary header prompt, a confirmation, a cancellation, and a cancellation and correction, and wherein when the user passive confirmation response is a cancellation and correction, the correction is processed by processing the correction to determine at least one possible recognition value for each slot contained in the correction. 35. The computer program product of claim 29, further including instructions that, when executed by the processor, cause the processor to: enable any unfilled slots in the segment of slots, wherein the primary header prompt elicits values for enabled slots in the segment. 36. The computer program product of claim 29, wherein the processing of the primary user response includes applying grammar rules to facilitate recognition of possible values for a corresponding slot. 37. The computer program product of claim 29, wherein the outputting the primary header prompt depends on the set of unfilled segments. 38. The computer program product of claim 29, wherein the outputting and the receiving is one of text-based and speech-based. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to speech recognition systems. More specifically, systems and methods for constructing a series of interactions with a user to collect multiple pieces of related information for the purpose of accomplishing a specific goal or topic (a multi-slot dialog) using a component-based approach are disclosed. 2. Description of Related Art Speech recognition systems are a promising method for automating service functions without requiring extensive changes in user behavior. Many companies have sought to expand or improve their customer service functions by using speech recognition technology to automate tasks that have traditionally been handled by human agents. To achieve this, speech recognition systems should allow a user to ask for and provide information using natural, conversational spoken input. Recent advances in certain areas of speech recognition technology have helped alleviate some of the traditional obstacles to usable speech recognition systems. For example, technology advances have enabled unrehearsed spoken input to be decoded under a wider range of realistic operating conditions, such as background noise and imperfect telephone line quality. Additionally, recent advances have allowed voice applications to recognize voice inputs from a broader population of users with different accents and speaking styles. Well-engineered voice systems achieve high customer acceptance. Unfortunately, building effective voice systems using past approaches has been difficult. The earliest approaches required programming in the application program interfaces (APIs) of the speech recognition engine. These approaches burdened developers with low-level, recognition engine specific details such as exception handling and resource management. Moreover, since these APIs were specific to a particular recognition engine, the resulting applications could not be easily ported to other platforms. The advent of intermediate voice languages such as VoiceXML as open standards somewhat simplified the development process. These intermediate voice languages accompanied a distribution of responsibilities in a voice system between a browser—which interprets the voice language and handles the telephony, voice recognition, and text-to-speech infrastructure—and a client application—which provides the user interaction code (expressed in the voice language). As a result, application developers no longer needed to worry about low-level APIs, but instead were responsible for generating documents that would be executed by the voice browser. Even with these advances, however, developing voice applications remained complex for a number of reasons. For example, voice applications present a new user interaction model that is sufficiently distinct from the (well understood) graphical user interface to require specialized design and implementation expertise. Speech interface concepts, such as dialog management, grammar optimization, and multi-slot interfaces, are manually implemented in every custom-built voice system. Given the relative newness of the speech paradigm, this further burdens the developers. In addition, the demands on applications to handle presentation, business logic, and data access functions resulted in piecemeal architectures combining static and dynamically generated documents, backend servlets, grammars, and other disjoint components. A number of products are available to simplify the development of enterprise voice applications. A central element of many of these products is a library of predefined and customizable voice components whose use reduces the amount of code that needs to be developed by a programmer. These components usually encapsulate the voice language code, grammars, internal call flows, prompts and error recovery routines required to obtain one piece of information from the caller, such as a date, a time, a dollar amount, a sequence of digits, or an item from a set or list of allowable items (such as a set of airports). A major limitation of these component frameworks is that the components are not combinable to allow the user to provide multiple pieces of information in each utterance. For example, a flight reservation application could use four components: a departure airport, a destination airport, a departure date and a departure time. The existing frameworks would allow a user to provide the four pieces of information in four separate utterances. However, if the application were to allow the user to say the departure airport, destination airport and departure date in one utterance (e.g. “I'm flying from Boston to San Francisco on Monday”), the departure airport, destination airport, and departure date components could not be simply combined. Instead, a new component would need to be developed with new grammars, call flows, prompts, etc. to recognize the two airports and the date. To carry the example further, if the application were to allow the caller to retain some pieces of information while changing others pieces of information (e.g. “No, I'm actually flying to Oakland on Tuesday”), an even more complex component would have to be developed. Because of these limitations, voice applications that rely on existing component frameworks implement highly directed dialogs in which the call flow is largely predetermined and each step accepts only a single item of information, such as in an interchange illustrated in FIG. 1a. Such voice systems are rigid and often penalize a caller who provides too much information, such as in an interchange illustrated in FIG. 1b. As a result, these systems are neither intuitive nor efficient since they cannot capture information rapidly or adapt to the user's preferences for providing information. What is needed is a voice application that utilizes a more intuitive, rapid and natural approach for obtaining information from a user such as a caller. SUMMARY OF THE INVENTION Systems and methods for constructing a series of interactions with a user to collect multiple pieces of related information for the purpose of accomplishing a specific goal or topic (a multi-slot dialog) using a component-based approach are disclosed. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, a method, or a computer readable medium such as a computer readable storage medium or a computer network wherein program instructions are sent over optical or electronic communication lines. Several inventive embodiments of the present invention are described below. The method generally includes outputting a primary header prompt to elicit values for slots in a segment from the user, receiving a primary user response containing a value for each slot in at least a subset of the slots in the segment, processing the primary user response to determine at least one possible recognition value for each slot contained in the primary user response, filling each slot contained in the primary user response with a matched value selected from the corresponding possible recognition values, and repeating the outputting, receiving, processing and filling for any unfilled slots in the segment until all slots in the segment of slots are filled. The method may include performing turns to confirm and/or clarify the matched slot values such as by silently accepting a best match, passively confirming the best match, actively confirming the best match, disambiguating among the best matches, and notifying the user of non-recognition. The method for confirmation and/or clarification may be selected based on, for example, the number of possible recognition values for the slots in the primary user response and a corresponding confidence level for each of the possible recognition values. With an active confirmation, a user confirmation response is recognized as a confirmation, a cancellation, or a cancellation and correction. With a cancellation and correction, the correction is processed by determining at least one possible recognition value for each slot contained in the correction. With a passive confirmation, a passive confirmation prompt is output with a next primary header prompt. The method may also include enabling any unfilled slots in the segment of slots, in which the primary header prompt elicits values for enabled slots in the segment. The method may be text- or speech-based. In another embodiment, a system for constructing and processing a multi-slot dialog with a user may generally include slot objects representing slots in a segment, each slot capable of being assigned a value based on the multi-slot dialog, at least one slot segment object each containing a corresponding set of slot objects, at least one set of slot group objects for each slot segment object, each slot group object defining parameters associated with a particular combination of slots in the slot segment object, and dialog objects that define a flow of the multi-slot dialog. The system may be implemented in an object-oriented programming language. According to another embodiment, a method for constructing a multi-slot dialog with a user to obtain multiple items of information over a number of turns may generally include providing at least one slot segment object, each slot segment object containing a corresponding set of slot objects, each representing a slot in a segment, each slot representing an item of information to be provided by the user, providing at least one set of slot group objects for each slot segment object, each slot group object defining parameters associated with a particular combination of slots in the slot segment object, and executing a multi-slot dialog flow defined by dialog objects. These and other features and advantages of the present invention will be presented in more detail in the following detailed description and the accompanying figures which illustrate by way of example principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. FIG. 1a and FIG. 1b illustrate examples of highly directed dialogs using conventional voice applications. FIGS. 2a-2c illustrates various examples of multi-slot dialogs. FIG. 3 is a block diagram of an illustrative multi-slot voice application system. FIG. 4 illustrates one embodiment of a framework for managing a multi-slot speech recognition-based conversation. FIG. 5 illustrates examples of segments for a multi-slot flight reconfirmation dialog. FIG. 6 illustrates the contents of one of the exemplary segments, namely, the flight itinerary, in the multi-slot flight reconfirmation dialog of FIG. 5. FIG. 7 illustrates examples of exchanges involved in a flight itinerary dialog. FIG. 8 is a flowchart illustrating various steps of an exemplary multi-slot dialog. FIG. 9 is a flowchart of an exemplary exchange using active confirmation. FIG. 10 is a flowchart of an exemplary exchange using passive confirmation. FIG. 11 is a flowchart illustrating an example of a conversation utilizing a go back functionality of a multi-slot dialog system. FIG. 12 is a flowchart illustrating an example of a conversation utilizing a change functionality of the multi-slot dialog system. FIG. 13 is a flowchart illustrating an example of a conversation utilizing a review functionality of the multi-slot dialog system. FIGS. 14 and 15 illustrate some of the possible slot group objects for the pre-recognition and post-recognition slot group classes for a flight itinerary segment, respectively. FIG. 16 is a block diagram illustrating an exemplary dialog flow structure. FIGS. 17 and 18 are flowcharts illustrating exemplary processing of the user's input in normal and passive confirm modes, respectively. FIG. 19 illustrates a possible grammar for an exchange with three slots. FIG. 20 illustrates a possible grammar for a confirmation exchange that includes accept and cancel grammars as well as grammars for the three slots being confirmed. DESCRIPTION OF SPECIFIC EMBODIMENTS Systems and methods for constructing a series of interactions with a user to collect multiple pieces of related information for the purpose of accomplishing a specific goal or topic (a multi-slot dialog) using a component-based approach are disclosed. The multi-slot dialog systems and methods obtain information from a user by conducting a speech-recognition based series of interactions. The systems and methods include determining the prompts output to the user as well as the grammars and semantic rules utilized to recognize user inputs such as utterances at each point in the conversation or interchange. The following description is presented to enable any person skilled in the art to make and use the invention. Descriptions of specific embodiments and applications are provided only as examples and various modifications will be readily apparent to those skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed herein. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention. FIGS. 2a-2c illustrate various examples of multi-slot dialogs. A multi-slot dialog has the objective of collecting multiple pieces of related information (“slots”) for the purpose of accomplishing a specific goal or topic, such as locating an airline reservation. In order to achieve a successful user interaction with the convenience and ease expected by humans, a multi-slot dialog application preferably handles certain behavior and interactions typical of human interactions in a spoken medium, including: (i) a caller may provide the slots in an arbitrary order, (ii) a caller may provide multiple slots in a single input such as a spoken utterance, (iii) a caller may provide only a subset of slots requested by the application in a single utterance, (iv) a caller may clarify or correct the application's interpretation of slots the caller has provided, (v) a caller may modify earlier slots in subsequent utterances. To satisfy these human interaction requirements, a dialog application may perform a lengthy and sophisticated call path of considerable complexity. However, conventional voice applications are ill-suited for implementing multi-slot dialogs. In particular, the dynamic order and combinations in which information may be provided cannot be easily handled by existing component frameworks and development methodologies of conventional voice applications that specify rigid, predetermined call flows. Rather than the manual approach, the multi-slot dialog systems and methods as described herein may be utilized for constructing multi-slot dialog applications using a component-based approach. Such component-based approach automates the multi-slotting process with components for the behavioral elements of a multi-slotting exchange between human and machine, including sequencing, grouping, prompting, confirmation, and/or modification strategies. FIG. 3 is a block diagram of an illustrative voice application system 300 that generally includes a telephone 301 in communication with a voice browser 303 via a telephone network 302 which is in turn in communication with a voice application 309 via a data network 308. The voice browser 303 includes the hardware and software for conducting bi-directional audio communications with a caller via the telephone network 302 and the telephone 301. The voice browser 303 may execute a program expressed in a voice language transmitted in the form of documents over the data network 308 (such as the Internet or an intranet) from the voice application 309. The voice browser 303 and voice application 309 may reside on any of various suitable computer systems. The voice language may be a markup language such as VoiceXML or Speech Application Language Tags (SALT). The voice browser 303 may include various components such as a speech recognition engine 304, a text-to-speech synthesizer 305, an audio playback player 306 for audibly rendering files recorded using generally available audio formats, and a component for handling calls over the telephone network 307. Commercially available and/or proprietary components for building voice applications may be employed in implementing any or all of the various components of the voice browser 303. The voice browser 303 may be responsible for detecting an incoming call, answering the incoming call, requesting an initial voice document from the voice application 309, and interpreting the voice document and executing instructions contained in the voice document according to the rules of the applicable voice language. The instructions may include the outputting of audible prompts to the user and the processing of voice responses from the user using specified grammars. In outputting the prompts to the user, the voice browser 303 may utilize the audio playback player 306 to audibly render prerecorded messages or may utilize the text-to-speech synthesizer 305 to audibly render text messages. The voice browser 303 can then generate actions in response to user events (such as spoken input or call disconnection) or system events (such as subsystem exceptions), and/or actions that may be defined in the current document or in another document to be fetched from the voice application 309. The overall architecture of the voice application system 300 having been described, a multi-slot framework implemented by the voice application system 300, such as by a combination of the voice browser 303 and voice application 309, will now be presented. A system implementing the multi-slot mode of conversation generally prompts the user with more open-ended questions while a system implementing a conventional directed dialog mode of conversation prompts the user with more specific prompts and accepts a more limited set of responses. FIG. 4 illustrates one embodiment of a multi-slot framework 401 for managing a multi-slot speech recognition-based conversation. In particular, the multi-slot framework 401 implements a multi-slot mode for obtaining information from a user. The framework 401 may include a multi-slot application 402 that manages the business logic and data access responsibilities for a set of slots 403. A slot is referred to herein as a data item whose value can be obtained from a user input such as a text input or a spoken utterance. For example, a flight reservation application may manage a departure airport slot whose valid values are found in a flight schedule database, and whose value, once uttered or otherwise entered by the user, should be stored in a reservation record. A multi-slot platform 404 constructs one or more voice interactions to obtain the desired slots from the user. FIG. 5 illustrates examples of segments for a multi-slot flight reconfirmation dialog and FIG. 6 illustrates the contents of one of the exemplary segments, namely, the flight itinerary, in the multi-slot flight reconfirmation dialog. In particular, a multi-slot dialog can be decomposed into sub-units at various levels. At the smallest level, a turn is an uninterrupted stream of input (e.g., speech) from one participant, i.e., the system or the user. Thus a system turn is one in which the system prompts the user with a message and a user turn is one in which the user makes an utterance that the system attempts to interpret. An exchange is a series of turns that captures the values for one or more slots from the user. Thus an exchange may include one or more confirmation, correction, or disambiguation turns until a final, single set of slot values is accepted by the system. A segment is a series of exchanges that captures a set of related slots. The segment is the largest unit of a dialog that allows all its associated slots to be provided in one user turn. In the example shown in FIG. 6, the five slots, namely, a departure airport, a destination airport, a date, a time, and an AM/PM indicator, form the flight itinerary segment such that up to all five slots of the flight itinerary segment may be entered in one user turn such as by the user uttering “from San Francisco to Boston tomorrow at 9AM.” Multi-slot dialogs can vary in complexity from single segment dialogs to complex, multi-segment dialogs in which each segment includes one or more slots. An example of a single-segment dialog is a phone attendant application that requests an employee name from the caller. In contrast, an example of a multi-segment dialog is a flight reconfirmation dialog such as that shown in FIG. 5. For example, the flight reconfirmation dialog may request a flight itinerary from the caller (which may include slots for the departure and destination airports as well as the date, time and AM/PM indicator of the departure as shown in FIG. 6), and may verify the caller's identity by requesting a record locator and by requesting personal details, such as a surname. FIG. 7 illustrates examples of exchanges involved in a flight itinerary dialog. The flight itinerary segment 701 contains 5 slots that represent a flight itinerary. In the first exchange 702, the system may prompt the user with “What is your flight itinerary?” to allow the user to enter information or values for up to all 5 slots. The user may respond with “I'm flying from Boston” and after any applicable confirmation/clarification turns, the application accepts Boston as the value for the departure airport slot. According to predefined logic, the application determines, for example, that only the destination airport should be prompted for in the next exchange 703, and outputs a prompt “And what is your destination?” After the user response is processed, the value San Francisco is stored in the destination airport slot. The application may then prompt for the remaining three unfilled slots in the next exchange 704 such as by outputting a prompt “And when are you flying?” The user's response of “next Friday at nine thirty AM” fills all three remaining slots and the dialog is complete. FIG. 8 is a flowchart illustrating an exemplary multi-slot conversation 800. At the start of an exchange at block 802, the voice application system outputs a primary header prompt to elicit values for a set of slots from the user. The system prompt is typically worded in such a way that the user may potentially provide values for a number of desired slots in one turn. At block 804, the user responds with a primary user turn in response to the output prompt. The user turn may provide one or more slot values. If the user turn is recognized by the system, a number of confirmation/clarification turns at block 806 may follow in which the system may optionally silently accept the best match, passively confirm the best match, demand active confirmation of the best match, disambiguate among the best matches, or notify the user of a non-recognition, for example, as will be described in more detail below. When the slot values from the turn are confirmed either explicitly or implicitly, the slots are filled with their respective values at block 808. Blocks 802-808 represent one exchange. When the current exchange is complete, the system determines if there are any remaining unfilled slots in the current segment at decision block 810. If all slots in the current segment are filled, then the system determines if there are any additional segment(s) of slots at decision block 812. If all slots in all segments are filled, then the multi-slot dialog 800 is complete. Alternatively, if there are remaining unfilled slots in the current segment and/or if there are additional segment(s) of slots, the dialog 800 returns to block 802 to initiated the next exchange. For example, the next exchange may either follow up on the previous exchange by prompting for any remaining slots that were not filled (e.g., “ . . . and around what time?”) or continue onto the next segment of slots by prompting for a new set of slots (e.g., “What type of car do you want to rent?”). As noted above, if the user turn is recognized, a number of confirmation and/or clarification turns may follow in which the system may optionally demand active confirmation of the best match, passively confirm the best match, disambiguate among the best matches, silently accept the best match, or notify the user of a non-recognition, for example. Details of the confirmation/clarification turns will now be described in more detail with reference to FIGS. 9 and 10. In particular, FIG. 9 is a flowchart of an exemplary exchange using active confirmation. In an active confirmation, a confirmation prompt is output to the user (e.g., “I think you said Austin to San Francisco. Is that correct?”). The confirmation prompt may escalate during an exchange if there are several confirmation cycles. The system may require that the user explicitly accept the value(s) for the associated slots prior to filling the slots. The user can cancel the previous recognized values by saying a cancel phrase such as “No” or “No, that's wrong.” In addition, to facilitate a more efficient interaction, the system may optionally accept an utterance by the user that includes a cancel phrase followed by a correction such as “No, I said Boston to San Francisco.” If the user cancels the previous recognized values, the system may clear all slot values recognized in the user turn and play a message such as “Let's try that again. What is your flight itinerary?” as shown in FIG. 9 and begin the exchange again. Alternatively, the system may treat the user response uttered in the user turn as a correction and repeat the confirmation/clarification turn, e.g., by prompting “OK. Boston to San Diego. Is that correct?” If the correction omits some of the slots that are being confirmed, the system may retain the previously uttered values of such slots. FIG. 10 is a flowchart of an exemplary exchange using passive confirmation. In a passive confirmation, the multi-slot dialog system outputs a prompt that is a combination of a passive confirmation prompt and a header prompt for the next exchange. As an example, the combined output prompt may be, for example, “Ok. Austin to San Francisco. And when are you flying?” As the user does not need to explicitly utter a confirmation if the values are correct, the passive confirmation technique facilitates in speeding up the dialog and thus is suitable for confirming recognition results where the system has a high level of confidence. When passive confirmation is utilized, the slots are filled with their respective values and those filled values may be removed or rolled back when the user utters a cancel phrase such as “No” or “No, that's wrong,” or a cancel phrase followed by a correction such as “That's wrong. I said Boston to San Francisco.” If the user issues a cancel via a cancel phrase, the system may clear the slot values accepted in the previous exchange, issue a prompt such as “Sorry, let's try that again,” and repeat the previous exchange. Alternatively, the system may treat the user response uttered in the user turn as a correction and repeat the confirmation/clarification turn, e.g., by prompting “OK. Boston to San Francisco. Is that correct?” If the user then utters an accept phrase such as “Yes” in response, the header prompt for the new exchange is repeated. As is evident, an active confirmation may be utilized after the user issues a cancel phrase in response to a passive confirmation. However, other confirmation types may be similarly utilized after the user issues a cancel phrase in response to a passive confirmation. If the next exchange contains a prompt for a “Yes/No” response, the functionality to rollback a previous passive confirm of the passive confirmation may be disabled. In a disambiguation, the system outputs a prompt containing a list of the top matches and requests the user to select one of the top matches, e.g., by its corresponding number. Each match may include a single slot value or a set of slot values and may be presented by a prompt similar to a confirmation prompt that contains all the recognized slot values. When a match is selected, the corresponding value or values are treated as if they had been uttered in the primary user turn and the system repeats the confirmation/clarification process. The system may also notify the user of a non-recognition. In particular, when a user turn is not recognized by the system, the system may issue an exception prompt such as “I didn't get that” and repeat the previous system turn or an amended version thereof. The system may be configured with various features and functionalities to further facilitate the exchange as will be described below in more detail with reference to FIGS. 11-13. For example, the system may be configured to maintain a skip list in a given exchange in which a skip list entry corresponding to the set of slot values presented in a confirmation is added each time a user cancels the confirmation during that exchange. The skip list helps to ensure that, within the same exchange, the system does not utilize and thus will not present again a set of values that matches an entry in skip list. Instead, the system may utilize the next best match when available. FIG. 11 is a flowchart illustrating an example of a conversation that includes yet another optional functionality of the system, namely, a go back functionality. Specifically, the user may utter a go back command, e.g., “go back,” at any time so as to return to the start of the previous turn, the start of the current exchange, or the start of the current segment, depending on the application. If the system goes back over a step that has filled some slots, these slots may be cleared. The multi-slot dialog system may be configured to adaptively present a more directed prompt after a threshold number of exceptions, corrections, or gobacks has occurred during an exchange. For example, the system may present a new, more directed header prompt “What date will you be picking up the car? For example, say tomorrow, next Tuesday, or July 24th.” If the exceptions, corrections or gobacks continue to occur, the system may transfer the user to a live operator for further assistance. FIG. 12 is a flowchart illustrating an example of a conversation that includes yet another optional functionality of the system, namely, a change functionality. The change functionality allows the user to change a previously filled slot value by uttering, for example, “I'd like to change the airport.” If the user's utterance requesting a change does not fill all the slots required for a change request, the system initiates a follow-up exchange such as “Departure or destination airport?” The change command may optionally be confirmed using any of the confirmation mechanisms described above. For example, the system may actively confirm the change command by prompting “I heard you say you wanted to change the arrival airport. Is that correct?” The change command cancels the exchange the user is currently in and clears at least some of the previously filled slot values. A new exchange then begins that prompts the user for the cleared slots which can be filled in one or more exchanges. Once the cleared slots are filled, the system continues processing and will bypass some previous exchanges if the slots associated with those exchanges are still filled. FIG. 13 is a flowchart illustrating an example of a conversation that includes yet another optional functionality of the system, namely, a review functionality. In particular, the user may request to review a previously filled slot value by uttering a request phrase such as “Can I check my date of departure?” In response to the review command, the system plays the filled slot value such as “You're flying on Friday, Aug. 9, 2002” and returns to the current exchange. If the user does not provide the values for all the slots required for a review request, the system initiates a follow-up exchange such as “Departure or return date?” Implementation of Multi-Slot Dialog An exemplary system or platform for implementing multi-slot dialogs will now be described. Merely by way of example, the platform for implementing multi-slot dialogs is described herein as being implemented utilizing Java. However, it is to be understood that the system may be implemented using any suitable programming language, preferably an object-oriented programming language such as Java or C++. The system generally includes slot objects, slot group objects, segment objects, and dialog objects. Each of these objects is described below. A slot object represents a slot which, as noted above, is an item of information to be obtained from the user. A slot object contains the grammar that recognizes the possible values that can be provided by the user for the corresponding slot, the rules that map grammar recognition results to semantic values for the slot, and the variables indicating the enabled and filled state (among other state variables) for the slot. The slot objects can be based on a Java interface that provides basic default functionality and/or functionality common to all slot objects. The grammar that recognizes the possible values that can be provided by the user for the corresponding slot is a formal specification of the utterances the system accepts for expressing the possible values for the slot. The grammar may include the vocabulary of words that may be used and valid structures for sequencing those words. For example, the grammar for a date slot should allow various date formats to be recognized, ranging from absolute specifications such as “January the twelfth two thousand and four” to relative forms such as “this coming Friday” and familiar terms such as “today” and “yesterday.” The grammar may also include fillers that may precede and/or follow the slot value in a user's utterance but that do not specify or distinguish one slot value from another. For example, an airport slot may have the preceding filler phrase “I'm flying from.” Some grammars may be highly application specific such as the grammar for the allowable airports in a flight reservation application. Other grammars may be reused across applications, such as the grammar for a date, a time, or a dollar amount. The common portion of these grammars may be predefined in a grammar object and customized for a particular slot. In addition to the rules of the grammar, each slot object also contains rules that map the grammar recognition results to semantic values for the corresponding slot that are meaningful to the specific application. For example, a destination airport slot object may map the utterances “San Francisco,” “San Francisco Airport,” “San Francisco International Airport,” and “SFO” to a single airport identifier such as “SFO.” As another example, a date slot object may map the utterance “tomorrow” to a date value that is computed as the next date following the current date. Each slot object also maintains a number of state variables or flags used during the execution of a multi-slot dialog to indicate the enabled and filled state (among other state variables) for the corresponding slot. Examples of flags include enabled, optional, filled, and pending flags. In particular, an enabled flag is set to true to indicate that a slot can be accepted in the upcoming user turn. An optional flag is set to true if an enabled slot does not need to be explicitly provided by the user. A filled flag is set to true when a slot value has been accepted after any applicable confirmation/clarification. A pending flag is set to true if a value for the slot has been recognized from the user but has not yet been accepted, e.g., pending confirmation. The system maintains slot group objects for each slot segment, examples of which are shown in FIGS. 14 and 15 for a flight itinerary segment. Each slot group object defines parameters or properties associated with a particular group or combination of slots in the slot segment. Examples of slot group properties include prompts such as header or main prompts, help prompts, error prompts, confirmation prompts, and/or disambiguation prompts, as well as recognition properties, i.e., variables that affect recognition behavior such as timeouts, recognition thresholds, recognition parameters, caching policies and so on. Different slot group classes, e.g., pre-recognition and post-recognition slot group classes as shown in FIGS. 14 and 15, respectively, may be defined to maintain separate sets of properties. Specifically, FIG. 14 illustrates some of the possible slot group objects for the pre-recognition slot group class for the flight itinerary segment. The pre-recognition slot group class may contain the prompts and recognition properties used before slot values are recognized, such as the header or main prompts, the help prompts, no match prompts, no input prompts, timeouts, confidence thresholds and so on. When the pre-recognition slot group class is used, the slot combination would typically be compared to the currently enabled set of slots. FIG. 15 illustrates some of the possible slot group objects for the post-recognition slot group class for the flight itinerary segment. The post-recognition slot group class may contain the prompts and recognition properties used after slot values are recognized, such as the active confirmation prompts, disambiguation prompts, passive confirmation prompts, and so on. When the post-recognition slot group class is used, the slot combination would typically be compared to the currently pending set of slots, i.e., the slots recognized from the user but not yet confirmed. When a parameter such as a prompt or a recognition property is required at a point in a multi-slot dialog, the system identifies a best match slot group object from a slot group class that contains the parameter and looks up the value of the desired parameter in the identified best match slot group object. For example, where a header prompt is required at a point in a multi-slot dialog in order for the system to elicit from the user the values for the slots in the currently enabled slot combination, e.g., date, time, and AM-PM, the system identifies a best match slot group object from the pre-recognition slot group class in FIG. 14. The system selects the slot group object whose slot combination is the closest to the currently enabled slot combination. The closest slot combination may be determined utilizing various suitable methods such as the most number of overlapping slots, the fewest number of non-overlapping slots in the slot group object, or the fewest number of non-overlapping slots in the enabled group. In the current example, the system identifies and utilizes the slot group object in the pre-recognition slot group class shown in FIG. 14 having an exact match slot combination as the currently enabled slot combination, i.e., date, time, and AM-PM. However, if an exact match slot group object is not found, another group object deemed as the closest may be identified and utilized, e.g., a group object with a two-slot combination such as time and AM-PM slots. The system may define a separate slot group object for each slot of the slot segment to ensure that a slot group can always be found for any enabled slot combination. The system also includes segment objects. A segment object maintains a set of slots in a slot segment that determines a series of one or more successive multi-slot exchanges. The values for the slots in a given slot segment may potentially be obtained from the user in a single exchange. Alternatively, if the user does not provide the values for all the slots in that segment in one exchange, follow-up exchanges are initiated until all required, i.e., non-optional, slots are filled. When a segment is filled completely, the next segment, if any, is then invoked. The system further includes dialog objects that define the dialog flow. While each multi-slot dialog can perform a different function, the dialog flow for each dialog generally has a common structure. FIG. 16 is a block diagram illustrating an exemplary dialog flow structure. After the system initiates a dialog at block 1601, the system obtains the first segment in the dialog at block 1602. The system determines the slots in this segment that should be enabled at block 1603 such as by including the slots that are not yet filled. The closest pre-recognition slot group is selected to retrieve the header prompt and other pre-recognition parameters at block 1604 (such as the help prompt and any exception prompts). The header prompt is usually worded in such a way that the user may potentially provide a number of desired slots in one utterance. For example, if the slots include a date slot, a time slot, and a meridian (AM/PM) slot, the prompt could be “When will you be picking up the car?” The user's response is then received and processed by the system at block 1605 such as by obtaining the best hypotheses of the user's intended word sequence from the speech recognition engine and performing any desired confirmation, clarification or disambiguation based on the custom settings of the application until a single set of slot values is accepted by the system. The system then determines whether the slot segment contains any more slots to be filled at decision block 1606 which usually includes slots whose values have not yet been filled. It is noted that the system, in determining whether the slot segment contains any more slots to be filled at decision block 1606, may apply application-specific logic specifying that some slot values may or should be automatically filled from other slot values, that some slots are optional, or that certain additional slots need to be filled as a result of the values of other accepted slots. If some slots do remain to be filled as determined in decision block 1606, the system returns to block 1603 to enable the next set of slots. Otherwise, the system continues to decision block 1607 to determine if there are any more slot segments. If there is at least one more slot segment remaining, the system obtains the next segment at block 1608 and returns to block 1603. Alternatively, if no other slot segments remain, the dialog ends at block 1610. When processing the user's input, the system may be in a normal mode or passive confirm mode. Passive confirm mode is activated when the system determines that the user's response should be passively confirmed based on some predefined criteria. One such set of criteria could be that the confidence level returned by the speech engine is below the threshold for silent acceptance but above the threshold requiring active confirmation. If passive confirm mode is not activated, the system may be in normal mode by default. FIG. 17 is a flowchart illustrating an exemplary processing of the user's input in normal mode while FIG. 18 is a flowchart illustrating an exemplary processing the user's input in passive confirm mode. The determination as to normal versus passive mode may be based on, for example, a weighted or average confidence level for the set of slots to which the user's response corresponds. When dealing with a user response with values for multiple slots, the determination may be made with a single determination for all slots in the user response or a separate determination for each slot in the user response and the separate results averaged or weighted, for example. In normal mode as illustrated in FIG. 17, the speech engine recognizes the user's input and returns one or more hypotheses at block 1701. If several possible matches are returned by the speech engine as determined at decision block 1702, the possible matches may be disambiguated at block 1708. For example, the user may be presented with a list of top matches and asked to select one. Each match may be presented by a disambiguation prompt similar to a confirmation prompt. When a match selected by the user is received and processed at block 1709, the system proceeds to the next exchange at block 1710. Alternatively, if only one hypothesis, i.e., the best match, is returned by the speech engine as determined at decision block 1702, the system determines whether the confidence level for the one hypothesis is at or above a predefined high confidence threshold at decision block 1703. If the high confidence level is at or above the high confidence threshold, the system accepts the slot values and enters passive confirmation mode at block 1707. Alternatively, if the high confidence level is below the high confidence threshold, the system actively confirms the best match by outputting a confirmation prompt at block 1704. For example, the system may construct the confirmation prompt by identifying the slot group in the post-recognition slot group class that is closest to the group of slots in the best match and retrieving the corresponding active confirmation prompt. The user's response to the confirmation prompt is received and processed at block 1705. If the user cancels the confirmation, e.g., by uttering a cancel phrase such as “no” or “that's wrong,” and provides a correction, the corrected values may return to block 1704 for confirmation. If the user cancels the confirmation with no correction, the current exchange is repeated at block 1706. In other words, any pending slot values are discarded or cleared and the system repeats the header prompt that was originally played. If the user accepts the confirmation, e.g., by uttering a phrase such as “yes” or “that's right,” the system accepts the slots values and proceeds to the next exchange at block 1710. In passive confirm mode as illustrated in FIG. 18, the confirmation prompt from one exchange is combined with the header prompt for the next exchange. For example, the combined prompt may be “Ok. Boston. And what date will you be flying?” The user's response is then recognized by the speech engine at block 1801. If the user's response does not begin with an accept or cancel phrase, i.e., a yes or no lead, as determined at decision block 1802, the user's response is processed as in the case of the normal mode described above. Alternatively, if the user response begins with an accept or cancel phrase as determined at decision block 1802, the previous slot values may be affected. If the user response is an affirmative user response, the header prompt for the new exchange may simply be repeated, for example “And what date will you be flying?” at block 1803. If the user response is a negative user response without a correction, the system may clear the slot values accepted in the previous exchange, play a message such as “Sorry, let's try that again,” and repeat the previous exchange at block 1804. For a negative user response with a correction, the corrected values are explicitly confirmed at block 1805 until the previous exchange's slots are explicitly accepted or cancelled. During a primary user turn, the system allows the user to provide values for one or more enabled slots. The grammar for the turn should thus be flexibly configured to recognize various flexible combinations of slots. For example, FIG. 19 illustrates a possible grammar for an exchange with three slots. Each branch of the diagram represents a grammar rule that could match the user's utterance. The grammars for slots 1, 2, and 3 are represented by reference numbers 1901, 1902, 1903, respectively. The postfix operator “?” applied to each of the grammars 1902, 1903 corresponding to slots 2 and 3 in the first branch indicates that slots 2 and 3 are optional such that in this first branch the user's utterance contains a value for slot 1, optionally a value for slot 2, and, if there is a value for slot 2, optionally a value for slot 3. Note that an application may restrict the allowed combination of slots (such as a slot having to come before another) depending on the norms of the language used and the context of a particular exchange. During a confirmation turn, the system allows the user not only to accept or cancel the confirmation, but also to provide corrected values. The grammar for a confirmation turn should thus be constructed to include the accept and cancel grammars as well as grammars for the slots being confirmed, an example of which is shown in FIG. 20. The accept grammar 2001 contains a set of phrases that express an affirmative response, such as “yes,” “that's right,” and “correct.” The cancel grammar 2002 contains a set of phrases that express a negative response, such as “no,” “that's wrong” and “incorrect.” If the cancel grammar is present, an optional correction grammar 2003 is included which recognizes new values for the slots being cancelled. While the exemplary embodiments of the present invention are described and illustrated herein, it will be appreciated that they are merely illustrative and that modifications can be made to these embodiments without departing from the spirit and scope of the invention. For example, although the multi-slot systems and methods described herein are well suited for voice interactions using speech recognition systems, the multi-slot systems and methods may also be adapted for use with text-based multi-slot interactions such as an interactive Internet-based multi-slot dialog. Thus, the scope of the invention is intended to be defined only in terms of the following claims as may be amended, with each claim being expressly incorporated into this Description of Specific Embodiments as an embodiment of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to speech recognition systems. More specifically, systems and methods for constructing a series of interactions with a user to collect multiple pieces of related information for the purpose of accomplishing a specific goal or topic (a multi-slot dialog) using a component-based approach are disclosed. 2. Description of Related Art Speech recognition systems are a promising method for automating service functions without requiring extensive changes in user behavior. Many companies have sought to expand or improve their customer service functions by using speech recognition technology to automate tasks that have traditionally been handled by human agents. To achieve this, speech recognition systems should allow a user to ask for and provide information using natural, conversational spoken input. Recent advances in certain areas of speech recognition technology have helped alleviate some of the traditional obstacles to usable speech recognition systems. For example, technology advances have enabled unrehearsed spoken input to be decoded under a wider range of realistic operating conditions, such as background noise and imperfect telephone line quality. Additionally, recent advances have allowed voice applications to recognize voice inputs from a broader population of users with different accents and speaking styles. Well-engineered voice systems achieve high customer acceptance. Unfortunately, building effective voice systems using past approaches has been difficult. The earliest approaches required programming in the application program interfaces (APIs) of the speech recognition engine. These approaches burdened developers with low-level, recognition engine specific details such as exception handling and resource management. Moreover, since these APIs were specific to a particular recognition engine, the resulting applications could not be easily ported to other platforms. The advent of intermediate voice languages such as VoiceXML as open standards somewhat simplified the development process. These intermediate voice languages accompanied a distribution of responsibilities in a voice system between a browser—which interprets the voice language and handles the telephony, voice recognition, and text-to-speech infrastructure—and a client application—which provides the user interaction code (expressed in the voice language). As a result, application developers no longer needed to worry about low-level APIs, but instead were responsible for generating documents that would be executed by the voice browser. Even with these advances, however, developing voice applications remained complex for a number of reasons. For example, voice applications present a new user interaction model that is sufficiently distinct from the (well understood) graphical user interface to require specialized design and implementation expertise. Speech interface concepts, such as dialog management, grammar optimization, and multi-slot interfaces, are manually implemented in every custom-built voice system. Given the relative newness of the speech paradigm, this further burdens the developers. In addition, the demands on applications to handle presentation, business logic, and data access functions resulted in piecemeal architectures combining static and dynamically generated documents, backend servlets, grammars, and other disjoint components. A number of products are available to simplify the development of enterprise voice applications. A central element of many of these products is a library of predefined and customizable voice components whose use reduces the amount of code that needs to be developed by a programmer. These components usually encapsulate the voice language code, grammars, internal call flows, prompts and error recovery routines required to obtain one piece of information from the caller, such as a date, a time, a dollar amount, a sequence of digits, or an item from a set or list of allowable items (such as a set of airports). A major limitation of these component frameworks is that the components are not combinable to allow the user to provide multiple pieces of information in each utterance. For example, a flight reservation application could use four components: a departure airport, a destination airport, a departure date and a departure time. The existing frameworks would allow a user to provide the four pieces of information in four separate utterances. However, if the application were to allow the user to say the departure airport, destination airport and departure date in one utterance (e.g. “I'm flying from Boston to San Francisco on Monday”), the departure airport, destination airport, and departure date components could not be simply combined. Instead, a new component would need to be developed with new grammars, call flows, prompts, etc. to recognize the two airports and the date. To carry the example further, if the application were to allow the caller to retain some pieces of information while changing others pieces of information (e.g. “No, I'm actually flying to Oakland on Tuesday”), an even more complex component would have to be developed. Because of these limitations, voice applications that rely on existing component frameworks implement highly directed dialogs in which the call flow is largely predetermined and each step accepts only a single item of information, such as in an interchange illustrated in FIG. 1 a . Such voice systems are rigid and often penalize a caller who provides too much information, such as in an interchange illustrated in FIG. 1 b . As a result, these systems are neither intuitive nor efficient since they cannot capture information rapidly or adapt to the user's preferences for providing information. What is needed is a voice application that utilizes a more intuitive, rapid and natural approach for obtaining information from a user such as a caller. | <SOH> SUMMARY OF THE INVENTION <EOH>Systems and methods for constructing a series of interactions with a user to collect multiple pieces of related information for the purpose of accomplishing a specific goal or topic (a multi-slot dialog) using a component-based approach are disclosed. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, a method, or a computer readable medium such as a computer readable storage medium or a computer network wherein program instructions are sent over optical or electronic communication lines. Several inventive embodiments of the present invention are described below. The method generally includes outputting a primary header prompt to elicit values for slots in a segment from the user, receiving a primary user response containing a value for each slot in at least a subset of the slots in the segment, processing the primary user response to determine at least one possible recognition value for each slot contained in the primary user response, filling each slot contained in the primary user response with a matched value selected from the corresponding possible recognition values, and repeating the outputting, receiving, processing and filling for any unfilled slots in the segment until all slots in the segment of slots are filled. The method may include performing turns to confirm and/or clarify the matched slot values such as by silently accepting a best match, passively confirming the best match, actively confirming the best match, disambiguating among the best matches, and notifying the user of non-recognition. The method for confirmation and/or clarification may be selected based on, for example, the number of possible recognition values for the slots in the primary user response and a corresponding confidence level for each of the possible recognition values. With an active confirmation, a user confirmation response is recognized as a confirmation, a cancellation, or a cancellation and correction. With a cancellation and correction, the correction is processed by determining at least one possible recognition value for each slot contained in the correction. With a passive confirmation, a passive confirmation prompt is output with a next primary header prompt. The method may also include enabling any unfilled slots in the segment of slots, in which the primary header prompt elicits values for enabled slots in the segment. The method may be text- or speech-based. In another embodiment, a system for constructing and processing a multi-slot dialog with a user may generally include slot objects representing slots in a segment, each slot capable of being assigned a value based on the multi-slot dialog, at least one slot segment object each containing a corresponding set of slot objects, at least one set of slot group objects for each slot segment object, each slot group object defining parameters associated with a particular combination of slots in the slot segment object, and dialog objects that define a flow of the multi-slot dialog. The system may be implemented in an object-oriented programming language. According to another embodiment, a method for constructing a multi-slot dialog with a user to obtain multiple items of information over a number of turns may generally include providing at least one slot segment object, each slot segment object containing a corresponding set of slot objects, each representing a slot in a segment, each slot representing an item of information to be provided by the user, providing at least one set of slot group objects for each slot segment object, each slot group object defining parameters associated with a particular combination of slots in the slot segment object, and executing a multi-slot dialog flow defined by dialog objects. These and other features and advantages of the present invention will be presented in more detail in the following detailed description and the accompanying figures which illustrate by way of example principles of the invention. | 20040706 | 20070605 | 20060112 | 95801.0 | G10L1518 | 1 | HAN, QI | MULTI-SLOT DIALOG SYSTEMS AND METHODS | UNDISCOUNTED | 0 | ACCEPTED | G10L | 2,004 |
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10,885,945 | ACCEPTED | Starter | An electric starter for an internal combustion engine comprises a switch (1) connectable to the starter motor of the engine, an actuator (3) for actuating the switch, and a removable operating element (4) for operating the actuator. The actuator (4) is a push-button actuator. | 1. An electric starter for an internal combustion engine, the starter comprising a switch connectable to the starter motor of the engine, a push-button actuator for actuating the switch, and a removable operating element for operating the actuator, the actuator being mounted within a housing associated with the switch, and the operating element being reciprocally mounted within the housing, wherein the operating element has a shaft and one end of the housing is provided with an aperture leading to its hollow interior, the aperture complementing the cross-section of the shaft, the shaft and the aperture being formed with complementary, interchangeable projection/recessed portions. 2-3. (cancelled) 4. A starter as claimed in claim 1, wherein the shaft is formed with an outwardly-extending key projection at one end thereof, and the aperture is formed with an outwardly-recessed portion whose shape complements that of the key projection. 5. A starter as claimed in claim 1, wherein the operating element is provided with a manually-engageable head portion at that end of the shaft remote from the key projection. 6. A starter as claimed in claim 1, wherein the actuator has a body portion fixed to the switch, and an actuator portion (push button) reciprocally mounted within the body portion for movement towards, and away from, the switch. 7. A starter as claimed in claim 4, wherein the body portion of the actuator is fixed within the housing by means of a screw-threaded connection. 8. A starter as claimed in claim 4, wherein the body portion of the actuator is fixed within the housing by snap-fitting. 9. A switch as claimed in claim 4, wherein the housing is fixed to the body portion of the actuator with the actuator portion positioned within its hollow interior and in alignment with the aperture in said one end of the housing. | This invention relates to an electric starter for a petrol powered lawnmower. A conventional petrol lawnmower is provided with a pull cord for starting the internal combustion engine of the lawnmower. This pull cord starter arrangement can be supplemented by the provision of an electric starter switch, the switch being operated by means of a key turning in a key slot provided in the switch housing. Such a switch is connected at one end of a wiring harness, with the engine starter motor and battery at the opposite end of the harness. One disadvantage of this known electric starter switch is that it is a relatively complicated and expensive construction. Moreover, there is a danger of the key being hit in use, which could lead to the key being broken within the key slot, in which case, a relatively costly repair would be necessary. The present invention provides an electric starter for an internal combustion engine, the starter comprising a switch connectable to the starter motor of the engine, an actuator for actuating the switch, and a removable operating element for operating the actuator, wherein the actuator is a push-button actuator. Preferably, the actuator is mounted within a hollow housing associated with the switch, and the operating element is reciprocally mounted within the housing. Conveniently, the operating element has a shaft, and one end of the housing is provided with an aperture leading to its hollow interior, the aperture complementing the cross-section of the shaft, the shaft and the aperture being formed with complementary, interengageable projection/ recessed portions. Advantageously, the operating element is provided with a manually-engageable head portion at that end of the shaft remote from the key projection. Advantageously, the body portion of the actuator is fixed within the housing by means of a screw-threaded connection. Alternatively, the body portion of the actuator is fixed within the housing by snap-fitting. Preferably, the actuator has a body portion fixed to the switch, and an actuator portion reciprocally mounted within the body portion for movement towards, and away from, the switch. Preferably, the housing is fixed to the body portion of the actuator with the actuator portion positioned within its hollow interior and in alignment with the aperture in said one end of the housing. The invention will now be described in greater detail, by way of example, with reference to the drawing, the single figure of which is a schematic representation of a petrol lawnmower electric starter switch arrangement. Referring to the drawing, an electric switch 1 for starting the internal combustion engine of a petrol powered lawnmower (not shown) is mounted within a housing 2. The switch 1 is provided with a push button actuator 3 having a body 3a and a push button 3b mounted for reciprocal movement within the body. A spring (not shown) is provided within the switch 1 to bias the push button 3b towards the position shown in the drawing. In order to actuate the switch 1, it is necessary to push the button 3b in the direction of the arrow A. The body 3a of the push button 3 is fixed within a bore 2a of the housing 2 by means of a screw-threaded connection. Alternatively, the body 3a of the push button actuator 3 is a snap fit within the housing 2. A removable button key 4 is provided for engagement with the actuator 3 to actuate the switch 1. The key 4 has a head 4a, generally cylindrical shaft 4b, and a key projection 4c. The bore 2a of the housing 2 has a stepped-in portion 2b at its free end, the diameter of this stepped-in portion being slightly greater than that of the shaft 4b of the key 4. A slot 2c, which complements the key projection 4c, is provided in the stepped-in portion 2b. In use, the key projection 4c of the key 4 is aligned with the slot 2c, and the key is pushed into the housing 2. Once the key projection 4c enters the bore 2a of the housing 2, the key 4 can be rotated to hold the key with in the housing, thereby preventing the key becoming accidentally loose in use. To start the lawnmower, the key 4 is then pressed into the housing 2 as far as possible, thereby pushing the button 3b in the direction of the arrow A against the force of the spring, and actuating the switch 1 to fire the engine starter motor. Once the lawnmower engine has started, pressure on the key 4 is relaxed, the button 3b returns to the position shown in the drawing under the action of the spring, and the key is held as a loose fit within the housing 2. A separate switch (not shown) known as an operator presence control or dead man's handle is provided for turning off the engine of the lawnmower. The main benefits of the electric starter switch arrangement described above are that it is cheaper to manufacture, and much simpler to operate than the known ignition key system, whilst maintaining the same safety advantages. Thus, the housing 2 and the key 4 can be manufactured very simply and cheaply by moulding processes using a plastics material such as glass-filled nylon or ABS, and the push button actuator 3 is a cheap and simple part to manufacture. | 20040707 | 20060704 | 20050203 | 99291.0 | 2 | LEE, KYUNG S | STARTER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,885,948 | ACCEPTED | ELECTRONIC ACCESS CONTROL DEVICE | Abstract of the Disclosure An electronic lock utilizes two microprocessors remote from each other for enhanced security. The first microprocessor is disposed close to an input device such as a keypad, and the second microprocessor is disposed close to the lock mechanism and well protected from external access. The first microprocessor transmits a communication code to the second microprocessor when it receives via the input device an access code that matches a preset access code. The second microprocessor opens the lock if the transmitted communication code matches a preset communication code. The dual-microprocessor arrangement is advantageously used in a voice controlled access control system and in a motorcycle ignition control system. The present invention further provides an electronic access control system which has a master electronic key having a preset number of access, and an electronic alarm system for a bicycle that has a remote control mounted in the helmet of the rider. | 1. An electronic control device comprising: a circuit having a portion deactivated during a first time period; the portion of the circuit enabled during a second time period, the portion of the circuit having an enable output signal generated in response to a sensed electromagnetic signal; the portion of the circuit having an enable input code output generated in response the electromagnetic signal; the portion of the circuit having an input code output generated in response to the electromagnetic signal; a microprocessor having an output signal generated during an operation mode if the input code matches an authorization code and the microprocessor having a sleep mode to conserve power; and, a driver having an output generated in response to the output signal generated by the microprocessor. 2. The device of claim 1, wherein the first period of time is fixed. 3. The device of claim 1, wherein the second period of time is fixed. 4. The device of claim 1, the portion of the circuit comprising a receiver. 5. The device of claim 1, the portion of the circuit comprising an antenna. 6. The device of claim 1, further comprising at least one of the following responsive to the output of the driver: a solenoid; an electromechanical relay; a DC motor; a solid-state relay; and, an alarm. 7. The device of claim 1, wherein an alarm is enabled in response to the output of the driver. 8. The device of claim 1, wherein an alarm is disabled in response to the output of the driver. 9. The device of claim 1, wherein the electromagnetic signal is infrared. 10. The device of claim 1, wherein the electromagnetic signal is within a radio frequency. 11. An apparatus comprising: a first circuit comprising an oscillator and having a first circuit output signal; a second circuit enabled and disabled in response to the first circuit output signal, the second circuit having a second circuit output signal generated in response to receipt of an electromagnetic signal; a third circuit enabled during the receipt of the electromagnetic signal, the circuit having a third circuit output signal comprising an input code generated in response to receipt of an electromagnetic signal; a fourth circuit enabled during an operation mode to compare the input code to an authorization code and having a sleep mode to conserve power; and, a driver having an output that is provided to a device if the input code matches the authorization code. 12. The apparatus of claim 11, the third circuit comprising a decode circuit. 13. The apparatus of claim 11, the device comprising at least one of the following: a solenoid; an electromechanical relay; a DC motor; a solid-state relay; and, an alarm. 14. The apparatus of claim 11, wherein the device is an alarm that is enabled in response to the output of the driver. 15. The apparatus of claim 11, wherein the device is an alarm that is disabled in response to the output of the driver. 16. The apparatus of claim 11, wherein the electromagnetic signal is infrared. 17. The apparatus of claim 11, wherein the electromagnetic signal is within a radio frequency. 18. An apparatus comprising: an oscillator having an output comprising a plurality of duty cycles; a circuit that is periodically enabled for a time t 1and disabled for a time t 2during at least some of the duty cycles; a portion of the circuit that generates an input code in response to an electromagnetic signal; a microprocessor that compares the input code to an authorization code during an operation mode and having a sleep mode to conserve power; a device responsive to a signal generated by the microprocessor, the device comprising at least one of the following: a solenoid; an electromechanical relay; a DC motor; a solid-state relay; and, an alarm. 19. The apparatus of claim 18, wherein t 2 is fixed. 20. The apparatus of claim 18, wherein the portion of the circuit is a decoder. 21. The apparatus of claim 18 further comprising an electromechanical driver electrically connected to the microprocessor. 22. The apparatus of claim 18, wherein the electromagnetic signal is infrared. 23. The apparatus of claim 18, wherein the electromagnetic signal is within a radio frequency. 24. A method comprising the steps of: deactivating a circuit during a first time period; enabling a portion of the circuit for a second time period; sensing an electromagnetic signal during the second time period; processing the electromagnetic signal to obtain an input code; comparing the input code to an authorization code during an operation mode and conserving power during a sleep mode; and, providing a signal to a device if the input code matches the authorization code. 25. The method of claim 24, wherein the first period of time is fixed. 26. The method of claim 24, wherein the second period of time is fixed. 27. The method of claim 24, further comprising the step of generating an oscillation signal and deactivating the circuit in response to the oscillation signal. 28. The method of claim 24, further comprising the step of operating at least one of the following in response to the signal to the device: an electromechanical driver; a solenoid; a DC motor; an electromechanical relay; a solid-state relay; and, an alarm. 29. The method of claim 24, wherein the device is an alarm and further comprises the step of deactivating the alarm. 30. The method of claim 24, wherein the device is an alarm and further comprising the step of activating the alarm. 31. The method of claim 24, wherein the electromagnetic signal is infrared. 32. The method of claim 24, wherein the electromagnetic signal is within a radio frequency. 33. The method of claim 24, further comprising the step of activating another portion of the circuit to compare the input code to the authorization code. 34. A method comprising the steps of: periodically enabling and disabling a circuit during each of a plurality of duty cycles wherein the circuit is enabled for a time t 1 during each of the duty cycles; receiving an input code transmitted via an electromagnetic signal; comparing the input code to an authorization code during an operation mode and conserving power during a sleep mode; enabling the circuit as the input code is being received for a time t 2; and, providing a signal to a device if the input code matches the authorization code. 35. The method of claim 34, wherein t 2 is fixed. 36. The method of claim 34, further comprising the step of sensing receipt of the electromagnetic signal. 37. The method of claim 34, wherein the electromagnetic signal is infrared. 38. The method of claim 34, wherein the electromagnetic signal is within a radio frequency. 39. The method of claim 34, further comprising the step of operating at least one of the following in response to the signal to the deice: an electromechanical driver; a solenoid; a DC motor; an electromechanical relay; a solid-state relay; and, an alarm. 40. The method of claim 34, wherein the device is an alarm and further comprising the step of deactivating the alarm. 41. The method of claim 34, wherein the device is an alarm and further comprising the step of activating the alarm. 42. A battery powered access control device for accessing a safe comprising: a non-volatile memory containing an access code; a circuit generating a wake-up signal in response to pressing either of at least two alphanumeric keys on a keypad used in entering an input code; a processor that is woke-up for a period of time in response to the wake-up signal, compares the input code with the access code, and generates a signal to open the safe if the input code matches the access code; wherein the processor enters a sleep mode after the period of time, the sleep mode causing the processor to operate at a lower power consumption rate than when the processor is awake. 43. The device of claim 42 further comprising a low-battery detection circuit that is enabled by the processor for measuring a voltage of a battery, and the detection circuit disabled when the processor is in a sleep mode. 44. The device of claim 42 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the processor and being enabled when the processor is in an operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level. 45. The device of claim 42, the keypad comprising a program key connected to an interrupt input of the processor, and wherein the processor is programmed to enter a code programming sequence in response to pressing of the program key, receive a first input code from the keypad, compare the first input code with the stored access code in the non-volatile memory, receive an additional access code from the keypad if the first input code matches the stored access code, and store the additional access code in the non-volatile memory. 46. The device of claim 42 further including a communication port operatively connected to the processor for sending the access code to the processor for writing into the non-volatile memory to form a stored access code. 47. The device of claim 46 wherein the processor is programmed to receive a serial number for the device through the communication port and write the serial number into the non-volatile memory. 48. The device of claim 42 further including a communication port operatively connected to the processor, and wherein the processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit the stored access code through the communication port. 49. The device of claim 48 wherein the non-volatile memory further contains a serial number for the device, and wherein the processor is further programmed to transmit the serial number through the communication port. 50. A method for accessing a safe comprising: storing an access code within a non-volatile memory; providing a wake-up signal in response to pressing either of at least two alphanumeric keys on a keypad used to enter an input code; waking-up a microprocessor for a period of time in response to the wake-up signal; transmitting an input code to the microprocessor; comparing the input code with the access code during the period of time; activating a lock actuator to open the safe if the input code matches the access code; entering a sleep mode after the period of time, wherein during the sleep mode the microprocessor operates at a lower power consumption rate than when the microprocessor is awake. 51. An alarm circuit connected to a battery, the alarm circuit comprising: a memory storing an access code; circuitry providing a wake-up signal and receiving a input code; a microprocessor operatively connected to the battery and woke-up for a period of time in response to the wake-up signal, the microprocessor comparing an input code with the access code during the period of time and deactivating an audible alarm if the input code matches the access code, the microprocessor entering a sleep mode after the period of time wherein during the sleep mode the microprocessor operates at a lower power consumption rate on the battery than when the microprocessor is awake. 52. The alarm circuit of claim 51 further comprising a motion sensor and wherein the audible alarm is activated when the motion sensor detects motion. 53. The alarm circuit of claim 51, the circuitry further comprising a receiver that receives the input code and is activated and deactivated by a timer. 54. The alarm circuit of claim 53, wherein the receiver is an infrared receiver. 55. The alarm circuit of claim 53, wherein the receiver receives data entered on a keypad. 56. The alarm circuit of claim 53, wherein the receiver is a keypad. 57. A battery-powered electronic access control device for accessing a safe comprising: a keypad having a plurality of alphanumeric keys and a program key mounted thereon; a microprocessor-based control circuit comprising a microprocessor comprising a non-volatile memory storing a permanent access code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon the pressing of either of at least two keys on the keypad; the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to switch from sleep-mode into an operation mode in response to pressing any of the alpha-numeric keys, receive an input key code through the keypad, compare the input key code with the permanent access code in the non-volatile memory and activate the lock actuator if the input key code matches the stored access code, the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the non-volatile memory as the access code for the access control device. 58. The electronic access control device of claim 57, the microprocessor-based control circuit further comprising a low-battery detection circuit that is enabled by the microprocessor in the operation mode for measuring a voltage of the battery and disabled when the microprocessor is in the sleep mode. 59. The electronic access control device of claim 57 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level. 60. The electronic access control device of claim 57, wherein the keypad includes a program key connected to one of the interrupt inputs of the microprocessor, and wherein the microprocessor is programmed to enter a code programming sequence in response to a pressing of the program key, receive a first input code from the keypad, compare the first input code with the stored access code in the non-volatile memory, receive an additional access code from the keypad if the first input code matches the stored access code, and store the additional access code in the non-volatile memory. 61. The electronic access control device of claim 57, further including a communication port connected to the microprocessor-based control circuit for sending an access code to the microprocessor-based control circuit for writing into the non-volatile memory to form the stored access code. 62. The electronic access control device of claim 61, wherein the microprocessor is programmed to receive a serial number for said electronic access control device through the communication port and write the serial number into the non-volatile memory. 63. The electronic access control device of claim 57, further including a communication port connected to the microprocessor-based control circuit, and wherein the microprocessor is programmed to receive a read signal through the communication port and in response to the read signal to transmit the stored access code through the communication port. 64. The electronic access control device of claim 61, wherein the non-volatile memory further contains a serial number for said electronic access control device, and wherein the microprocessor is further programmed to transmit the serial number through the communication port. 65. An electronic access control device comprising: first and second controllers separated from each other, wherein the second controller is shielded from external access and comprising a memory for storing a communication code; the second controller receiving a request and transmitting the communication code to the first controller; the first controller receiving an input access signal from a key or keypad, and comparing the input access signal to a stored access code to determine if the input access code is valid; the first controller sending the communication code to the second controller if the input access code is valid, wherein the second controller provides a signal to energize a circuit to access a lock. 66. The electronic access control device of claim 65 wherein the communication code is substantially permanently stored in the memory of the second controller. 67. The electronic access control device of claim 65 wherein the second controller transmits the communication code to the first controller during initialization. 68. The electronic access control device of claim 65 wherein the second controller transmits the communication code to the first controller before the first controller receives the input access signal. 69. A method comprising the steps: storing a communication code in a memory of a second controller separated from a first controller, the second controller shielded from external access; receiving a request and transmitting the communication code from the second controller to the first controller; transmitting an input access signal from a key or keypad to the first controller; comparing the input access signal to a stored access code to determine if the input access code is valid; sending the communication code to the second controller if the input access code is valid, wherein the second controller energizes a circuit to access a lock. 70. The method of claim 69 further comprising the step of storing the communication code as a substantially permanent code in the memory of the second controller. 71. The method of claim 69 wherein transmitting the communication code from the second controller to the first controller occurs during initialization. 72. The method of claim 69 wherein transmitting the communication code from the second controller to the first controller occurs before the first controller receives the input access signal. 73. An electronic access control device comprising: a microprocessor-based control circuit comprising a microprocessor and a non-volatile memory; and, at least two communication ports operatively coupled to the control circuit, the first port receiving an input code to control a lock actuator, and the second port dedicated to reading an access code from the non-volatile memory upon the second port receiving a communication signal, wherein if the input code received by the first port matches the access code, then the lock actuator unlocks a lock. 74. An electronic access control device comprising: a microprocessor-based control circuit comprising a microprocessor and a non-volatile memory; and, at least two communication ports operatively coupled to the control circuit, the first port receiving an input code to control a lock actuator, and the second port dedicated to writing an access code to the non-volatile memory, wherein if the input code received by the first port matches the access code, then the lock actuator unlocks a lock. 75. An electronic access control device comprising: a microprocessor-based control circuit comprising a microprocessor and a non-volatile memory; and, at least two communication ports operatively coupled to the control circuit, the first port receiving an input code to control a lock actuator, and the second port dedicated to writing and reading an access code from the non-volatile memory, wherein if the input code received by the first port matches the access code, then the lock actuator unlocks a lock. 76. A battery-powered electronic access control device comprising: a keypad having at least one row of keys mounted thereon, the keypad comprising a program key for pressing by a user to enter a user input; a microprocessor-based control circuit comprising a microprocessor and a non-volatile memory storing a permanent access code, the microprocessor comprising multiple inputs for receiving an interrupt signal, and the program key operatively connected to one of the multiple inputs, the microprocessor programmed to enter a sleep mode to conserve battery power between operations and to awaken from the sleep mode upon pressing of either of at least two keys on the keypad, including the keys on the keypad used to enter an input code; the microprocessor-based control circuit operatively connected to the keypad for receiving the user input, the microprocessor configured to switch from the sleep mode into an operation mode and to enter a code programming operation in response to pressing of the program key, receive a first key code in response to detecting the pressing of the program key, compare the first key code with the permanent access code, receive a second key code, and store the second key code in the volatile memory as an access code for the access control device if the first key code matches the permanent access code in the non-volatile memory. 77. An electronic access control device comprising: a microprocessor-based control circuit comprising a microprocessor and non-volatile memory containing an access code for the electronic access control device; and a communication port connected to the microprocessor-based control circuit, the microprocessor being programmed to receive a read signal through the communication port, and in response to the read signal transmit the access code in the non-volatile memory out through the communication port; and, wherein the access code is a substantially permanently stored access code. | Detailed Description of the Invention RELATED APPLICATION This application is a continuation of copending U.S. patent application Serial No. 10/024,945 filed on December 19, 2001, which is a continuation of U.S. patent application Serial No. 08/760,062 filed on December 4, 1996 now U.S. Patent No. 6,359,547, which is a continuation-in-part of U.S. patent application Serial No. 08/339,555 now U.S. Patent No. 5,617,082 of Denison et al., similarly entitled “ELECTRONIC ACCESS CONTROL DEVICE UTILIZING A SINGLE MICROCOMPUTER INTEGRATED CIRCUIT,” filed on November 15, 1994, wherein all of the above related applications are incorporated by reference. This application is also related to co-filed application U.S. Serial No. 10/885,998, entitled, “ELECTRONIC ACCESS CONTROL DEVICE.” FIELD OF INVENTION This invention relates generally to access control devices, and more particularly to electronic access control devices controlled by microprocessors. BACKGROUND OF THE INVENTION An electronic access control device, such as an electronic combination lock or an electronic alarm system, allows the user to activate or deactivate the access control without the use of the conventional key and mechanical lock mechanism. With the development of microprocessor integrated circuits, it is becoming common to implement microprocessor-based control circuitry in electronic access control devices. Electronic access control devices are known, for example, from U.S. Pat. No. 5,021,776. In this device, and other common electronic access control devices, a microprocessor is used in combination with a keypad and an electrically programmable read only memory (EPROM). The microprocessor compares the combination entered in the keypad by the operator with the combination stored in the EPROM. If the two combinations match, the microprocessor opens the lock. There are problems associated with previous electronic access control devices. One area of problems concerns the manufacture of the devices, including the difficulty in programming the non-volatile memory, such as the EPROM, for storing the access code and other useful information for the operation of the device. EPROMs, which usually require parallel programming, interrupt the manufacturing process in that they restrict when the manufacturer can program the device. A manufacturer would prefer to program the access code into the EPROM as the last step in the manufacturing process. However, with parallel EPROMs, burning in the code after the device has manufactured is difficult. After the device is soldered together, the manufacturer must contend with integrated circuit pin clips and must worry about interference with other circuitry on the manufactured device. Further, manufacturing, with known electronic access control devices, requires many pin connections which increase manufacturing cost. Related to the problems associated with the pin connections of the microprocessor integrated circuit (IC) is the concern of device reliability and ease of use. When the device contains a significant number of pin connections, the reliability of the device decreases. Further, serial access to the EPROM to determine the electronic access code is easier than parallel access in terms of pin connections. When the user forgets or loses the access code in the EPROM, a locksmith could plug into the device and retrieve the access code serially without breaking into the safe. However, with parallel EPROMs, serial access is not available. One common problem associated with previous electronic locks is their potential vulnerability to tampering. A conventional electronic lock receives an access code via an input device such as a keypad or electronic key reader, verifies the access code, and then energizes a solenoid, relay, motor, or the like to open the lock. This arrangement is vulnerable to tampering because if the control circuit is somehow broken in or removed, one can open the lock by "hot-wiring" the control lines for activating the lock-opening mechanism. Another technically challenging problem is related to the need to provide electrical energy to power the operation of the electronic access control device. For many applications, it is desirable to use a portable energy source, such as a battery, to power the access control device. A battery, however, has a rather limited amount of electrical energy stored therein. Thus, it is extremely important to reduce the power consumption of the control circuit and peripheral devices of the access control device to extend the service life of the batteries. For instance, it is typical to use a solenoid-operated lock in an electronic lock. The power consumed by the solenoid in opening the lock is quite significant. Thus, the battery can be rapidly drained by the repeated operation of the solenoid. As another example, it is common to include a low-battery detection circuit in an electronic lock to provide a warning signal to the user when the battery voltage falls below a predetermined level. The operation of the low-battery detection circuit, however, also consumes electrical energy and contributes to the draining of the battery. Some electronic locks are provided with electronic keys. When an electronic key is presented to a key reader of an associated electronic lock, it transmits an access code to the electronic lock. By using an electronic key, the user does not have to enter manually the access code by means of a keypad. In certain applications, a remote control unit is used which has a radio transmitter to send the access code to the lock without direct electrical contact with the electronic lock. Although electronic keys are a convenient feature, they have their associated problems. One problem is related to the unauthorized use of the keys. For example, many hotels provide safes equipped with electronic locks in their hotel rooms. Such safes typically allow the hotel guests to set their own access codes. In cases where the hotel guests forget the access codes they set, the hotel management has to send someone with a master key which has a master access code stored therein to open the safes. There is a danger that such a master key may be used for unauthorized opening of other safes in the hotel. Another problem associated with the use of an electronic key or a wireless access code transmitter is that the key or the transmitter may be lost easily, or the user may simply forget to bring the key or transmitter. This problem is especially serious if the electronic access control device does not provide other means, such as a keypad, for entering the access code. SUMMARY OF THE INVENTION It is a general object of the present invention to develop an electronic access control device which is easier to manufacture and more reliable to operate, and provides improved security to prevent tampering or unauthorized access. It is an object of the present invention to provide an electronic access control device with a non-volatile memory for storing an access code that permits the manufacturer of the device to easily insert the access code into the device and then read out the code for verification. It is an object of the present invention to provide an electronic access control device that provides significantly enhanced security and reduced vulnerability to tampering as compared to previous electronic locks. It is an object of the present invention to develop an electronic access control device which has fewer total components and pin connections for smaller device area and greater reliability. It is another object of the present invention to develop an electronic access control device with a solenoid-operated lock which has reduced power consumption by reducing the power used in operating the solenoid. It is a related object of the present invention to develop an electronic access control device that has an improved low-battery detection circuit which has minimized energy consumption. It is a more specific object of the present invention to provide an electronic alarm system for a bicycle that uses a wireless transmitter for sending an access code for activating and deactivating the alarm system and that is configured to help the rider of the vehicle to prevent losing the transmitter or forgetting to bring the transmitter. It is another more specific object of the present invention to provide an electronic access control system with a master key for a plurality of remote electronic locks that effectively prevents the unauthorized use of the master key. The present invention accomplishes these and other objects and overcomes the drawbacks of the prior art. First, there is provided an electronic access control device which reduces the number of pin connections required to manufacture, to read, to program, and to operate the device. The device multiplexes the inputs and outputs of the microprocessor IC so that a single pin can function as an input in one mode and an output in another. The microprocessor determines, based on the mode of operation, whether a pin functions as an input or an output. The electronic access control device of the present invention has a communication port connected to selected pins of the microprocessor IC for accessing the non-volatile memory for storing an access code. Through the communication port, the manufacturer can interact with the microprocessor to store an access code into the non-volatile memory and retrieve the access code for verification. By virtue of the provision of the communication port, the factory-programmed access code can be saved into the non-volatile memory after the control circuitry is completely assembled. In one embodiment, the electronic access control device has a microprocessor IC with a plurality of pins, a keypad for inputting user-entered access codes and a non-volatile memory, such as an EEPROM, external of the microprocessor for storing an access code. At least one of the IC pins is connected to both the keypad and the non-volatile memory for receiving the user-entered code from the keypad and transferring data between the IC and the memory. In accordance with the object of the invention to reduce the vulnerability to tampering, the present invention provides an electronic access control device which has two microprocessors. The first microprocessor is preferably disposed close to the user interface such as a keypad or an electronic key reader. The second microprocessor is preferably disposed close to the lock mechanism and substantially shielded from external access. When the first microprocessor receives a user-entered code, it compares the entered code to a stored access code. If those two codes match, the first microprocessor transmits a special communication code to the second microprocessor. The second IC opens the lock if the transmitted communication code matches a stored communication code. Since the second IC is well protected from external access, the risk of tampering by hard-wiring is significantly reduced. This dual-microprocessor arrangement is advantageously used in a voice activated access control system which has a first microprocessor circuit having speech recognition capability, and a second microprocessor circuit which carries out a commanded operation when receiving a correct communication code from the first microprocessor circuit. The first microprocessor circuit may include a transmitter for wireless transmission of the communication code. The dual-microprocessor arrangement is also advantageously used in a motorcycle ignition switch control system for turning on accessories or starting the engine in response to the ignition key position. The present invention also provides an effective solution to the problem associated with the intensive need for power of the solenoid. In the present invention, the electronic access control device pulses the power to the solenoid so that the overall power consumption in operating the solenoid is lower. Thus, the battery has a longer life and the lock has an increased number of accesses. In accordance with a related aspect of the present invention, the electronic access control device employs a low-battery detection circuit that is turned off and therefore consumes no electrical power when the microprocessor is in the sleep mode. The low-battery detection circuit uses a combination of a voltage divider and a transistor to compare the battery voltage and the regulated voltage for determining whether the battery voltage is low, and uses another transistor in series with the voltage divider to selectively turn the current through the voltage divider on and off. When the current through the voltage divider is off, the low-voltage detection circuit does not consume electrical energy. In the case of an electronic access control system with a master key and a plurality of remote electronic locks, the present invention effectively prevents unauthorized use of the master key. In accordance with the present invention, the master key has a master access code and a number of access stored therein. Each of the remote electronic lock has a key reader to communicating with the master key. When an electronic lock detects in the key a correct master access code and a number of access that is at least one, it opens the associated lock and decrements the number of access in the key by one. In accordance with another aspect of the present invention, there is provided an electronic alarm system for a bicycle or a similar manually powered vehicle. The alarm system includes a remote control unit installed in the helmet of the rider of the bicycle, and an electronic alarm installed on the bicycle. The remote control unit has a transmitter for the wireless transmission of control signals to activate or deactivate the alarm on the bicycle. The alarm on the bicycle includes a motion detector for sensing the movement of the bicycle. If the motion detector detects the movement of the vehicle when the electronic alarm is activated, the alarm is set off. It is a feature of the present invention to mount the remote control in the helmet of the rider of the bicycle. By virtue of this arrangement, the rider is more likely to remember to wear the helmet. The risk of losing the remote control is also substantially eliminated. These and other features and advantages of the invention will be more readily apparent upon reading the following description of the preferred embodiment of the invention and upon reference to the accompanying drawings wherein. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an electronic access control device having a keypad; FIG. 2 is a block diagram of the electronic access control device of FIG. 1; FIG. 3 is the schematic of the electronic access control device; FIG. 4 is the flow chart at power-up of the device; FIG. 5 is the flow chart of the device in normal operation; FIG. 6 is a block diagram of a remote access control device; FIG. 7 is a schematic of the input electronics of the remote access control device of FIG. 6; FIG. 8 is a schematic of another embodiment of the electronic control access device which has a non-volatile memory sharing certain pins of a microprocessor with a keypad; FIG. 9 is a functional block diagram showing an embodiment of an electronic access control device having two microprocessors communicating with each other to provide enhanced security of the device; FIGS. 10A and 10B are schematic views together showing an application of the dual-microprocessor configuration of FIG. 9 in an electronic combination lock; FIG. 11 is a functional block diagram showing an application of the dual-microprocessor configuration of FIG. 9 in an ignition control system for a motorcycle; FIG. 12 is a functional block diagram showing an application of the dual-microprocessor configuration of FIG. 9 in a voice controlled access control device; FIG. 13 is a functional block diagram showing another embodiment of the voice controlled access control device; FIG. 14 is a functional block diagram showing another embodiment of the voice controlled access control device which has a central control station and remote devices; FIG. 15 is a schematic view showing an electronic access control system which has a master key for opening a plurality of remote electronic locks; and FIG. 16 is a schematic view of an electronic alarm system for a bicycle which has a remote control unit mounted in a riding helmet and an electronic alarm mounted on the bicycle. While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments hereof have been shown in the drawings and will be described below. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention as defined by the appended claims. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, there is shown in FIG. 1 an illustrative electronic access control device 10 having a keypad 11, light emitting diodes (LEDs) 12 and 13, and a mechanical lever arm 14. In this illustration, the device is used as a lock for an office safe. The device can also be applied to various applications including locks for vending machines or amusement games. The main components of the electronic access code device are shown in FIG. 2 which include a keypad 11, a microprocessor 14, an access code input and output 15, an acoustic output (a piezo ceramic bender, Model No. KB1-1541) 16, LEDs 12 and 13, a voltage regulator (LM2936Z-5.0) 17, a battery 18, an electromechanical driver output 19, an oscillator 20, and a reset circuit 21. Inputs to the device may take the form of a thumbprint scan, a retinal scan, or a magnetic strip input which may work in conjunction with a keypad or as a sole means of input. Outputs may take the form of an alpha-numeric display which may work in conjunction with an acoustic output or an LED or as a sole means of output. The manufacturers which provide microprocessors applicable to the device include: Micro-Chip (PIC 16C54, PIC 16C57, PIC 16C71, PIC 16C76); Motorola (MC68HC705J1, MC68HC705K1, MC69HC705P6, MC68HC705P8, MC68HC705P9); National Semiconductor (COP 820C); SGS-Thomson (ST 6210); Texas Instruments (370C311); Zilog (Z84C01). A more detailed schematic of the device is shown in FIG. 3, highlighting the reduced pin configuration and the serial access to the electrically programmable read only memory (EPROM) 22. Several of the pins on the microprocessor 14 are multiplexed and perform multiple functions, at times used as inputs and at times used as outputs; thereby, the pin configuration is able to use only 9 pins for the keypad input, the acoustic output, and the EPROM 22 reading and writing. For example, the 12 keypad entries are shown in rows and columns. Each keypad entry in a row is connected to the corresponding pin. For example, keypads "3", "6", and "9" are connected to pin R1. Each keypad entry in the same column is connected to a corresponding pin as well. For example, keys "3", "0", "1", and "2" are all connected to pin C3. The multiplexing of the keypad allows for input of twelve different inputs ("0" through "9", PROG, and CLR) using a four by three configuration, as shown in FIG. 4 and FIG. 5. In particular, there are four rows and three columns in this configuration. In accordance with another embodiment, a keypad with four different inputs allows for as little as a two by two configuration through multiplexing the inputs. The following example will illustrate the multiplexing with respect to the keypad 11. Normally, in sleep mode, pins R1, R2, R3 and R4 are waiting for an input. When, for example, the keypad "3" is input, pin R1, which keypad "3" is connected to, is triggered signifying to the microprocessor 14 that an interrupt has occurred. The microprocessor 14 then executes an interrupt in the software program and changes one of the four pins (R1, R2, R3 and R4) into an output whereby a logic high is sent to the R1 pin. When a keypad is pressed, it acts as a short circuit; thus, when the microprocessor 14 sends out a logic high, it then senses pins C1, C2 and C3 to determine exactly which keypad in the row has been pressed. In this case, where keypad "3" is input, C3 is high. Pressing keypad "3" acts as a short circuit so that when R1 is sent high, there is a direct electrical connection between pin R1 and C3 via keypad "3". Thus, the microprocessor 14 can determine that keypad "3" was pressed based on R1 and C3 both being logic high. Another example of using multiple functions as connected to a single pin is the acoustic output 16. The acoustic output 16 is connected, via a transistor, to pin C2. Pin C2 is also connected to keypads "CLR", "4", "5", and "6". When the microprocessor 14 sends an audible signal output, pin C2 acts as an output. When the microprocessor is sensing the keypad input, C2 acts as an input. A further example of multiple functions as connected to a single pin is the EPROM 22 sensing function. The EPROM 22, as shown in FIG. 3, is part of the microprocessor 14. The DATA line (bidirectional in that the line is able to input data to write and output data to read) and CLOCK line of the EPROM 22 are connected to C1 and C2, respectively. Pins C1 and C2 are connected to the keypad as well. When the PROGRAM signal is input, C1 and C2 function. as inputs when writing to the memory location in the EPROM and function as outputs when reading from the memory location in the EPROM 22. Through this arrangement, the manufacturer may serially program the device with the access code. The microprocessor 14 uses registers 56 to transmit the incoming serial data into parallel data for the EPROM 22 to input. Further, the end user may read the EPROM 22 access code serially as well. In reading the EPROM 22, only three pins must be accessed (PROGRAM, DATA, and GROUND). The microprocessor 14 uses registers 56 to transmit the outgoing parallel data from the EPROM 22 to serial form for output. It will be appreciated that by installing a communication port, namely the access code I/O 15, in the microprocessor-based control circuit, the manufacturer of the device can access the EPROM by interacting with the microprocessor 14 via the communication port. By virtue of this arrangement, the manufacturer can program the access code into the EPROM as the last step in the manufacturing process, i.e., after the control circuit has been fully assembled. Thus, there is no longer the need to use a EPROM that is pre-programmed with access codes, or to attempt to input the access code into the EPROM by means of pin clips or the like during the manufacturing process. This ability to program the EPROM after the completion of the control circuit imparts significant flexibility, efficiency, and reliability to the manufacturing process. The operation of the electronic access code device is shown in flowchart form in FIG. 4 and FIG. 5. FIG. 4 shows the initialization sequence of the device upon power-up 24. The microprocessor, which contains an EPROM 22 and a random access memory (RAM) 23, checks to see if there is an access code stored 25 in the EPROM 22. The microprocessor 14 performs this operation by checking if a proprietary bit sequence is set, wherein the particular sequence of bits signifies that the EPROM 22 has a stored access code. If the bit sequence is present, the EPROM 22 contains the access code, whereby the microprocessor 14 waits for input from the keypad or waits for an external read signal 26 from the microprocessor 14. If the bit sequence is not present, the EPROM 22 does not contain the access code in its memory. The microprocessor 14 must then wait for the external program signal 28 which signifies that the access code is being written to the EPROM 22. The external program signal, as shown in FIG. 3, is labeled PROGRAM and is connected to pin I04 and pin IRQ of the microprocessor 14. In this mode, when the PROGRAM signal is toggled, this signifies that the access code is being burned into the EPROM 22. The microprocessor 14 then uses the CLOCK and DATA lines to clock in the data thereby reading the access code. Then, the microprocessor 14 stores the access code into memory 30. The microprocessor 14 subsequently sets the proprietary bit sequence on the EPROM 22 signifying that the EPROM 22 contains the access code. Finally, the microprocessor 14 waits for input from the keypad or waits for an external read signal 26 from the microprocessor 14. The EPROM 22 can also be used to store features other than the access code. It can be used to determine such things as: (1) the amount of time the solenoid 31 is to be energized upon opening the lock; (2) the number of key presses in the access code; (3) the option of disabling the permanent access code temporarily when a new-access code is stored in RAM 23; (4) the device serial number; and (5) the date and time the device was manufactured or put in service. These features allow the manufacturer to deliver to an original equipment manufacturer (OEM) customer a generic electronic lock assembly. The OEM customer may then. characterize all the specific lock features at the OEM customer facility. As shown in FIG. 5, after the power-up initialization routine, the microprocessor waits for an entry from the keypad 32. Several functions are available based on the keypad entry. If the program key (PROG key) is first pressed, the operator wishes to input an additional access code 33. In this mode, the microprocessor 14 inputs the next five numbers from the keypad 34, 35, 36, 37, and 38. The comparator 57, within the microprocessor 14, compares the two numbers and checks if the input number matches the access code 39 from the EPROM 22 which is stored in RAM 23. If the two numbers match, this signifies that the operator knows the access code in the EPROM 22 and therefore has clearance to input an additional access code 40. Thus, the microprocessor accepts the next five numbers from the keypad as the additional access code 41, 42, 43, 44, and 45, and stores the new access code 46 in RAM 23. The operator may then input either the access code from the EPROM 22 or the additional access code to open the lock. The operator may repeat this procedure and place additional access codes into RAM 23. The additional access codes will be stored in RAM 23 until the power is removed from the microprocessor 14 at which time the RAM 23 memory will be lost. An alternate mode of using the PROG key is to disable the permanent access code in the EPROM 22 temporarily when a new access code is entered into RAM 23. After the PROG key is hit, the microprocessor 14 inputs the next five numbers 34, 35, 36, 37 and 38. The comparator 57, within the microprocessor 14, compares the input number with the permanent access code 39 from EPROM 22. If the two numbers match, the microprocessor 14 inputs a second access code 41, 42, 43, 44, 45. In this alternative, when the microprocessor 14 stores in RAM 23 the new access code 46, it disables access to the permanent access code in RAM 23. Therefore, until the battery 18 is turned off, the only access code available is the new access code stored in RAM 23. If an operator enters the PROG key at any time other than at the first keypad entry from sleep mode, the microprocessor will display the error message 47 by sounding the acoustic output 16 through pin C2 and the LED 13. If a number from the keypad 11 is first entered while in sleep mode 48, the microprocessor 14 waits until another four numbers are entered 49, 50, 51, and 52, from the keypad 11. The microprocessor 14 then compares the number entered from the keypad 11 with the access code 53 stored in RAM 23. If the numbers match, the microprocessor 14 energizes the solenoid 31 at the output 54. The microprocessor 14 can also energize a DC motor, an electromechanical relay, or a solid-state relay. If the numbers do not match, the error message is sent 47 by sounding the acoustic output at pin C2. If the clear key on the keypad is entered at any time in the operation of the device, the microprocessor 14 waits 5 seconds before going back into sleep mode and waiting for the next keypad entry. One feature of the device is a lockout of keypad operations. If the microprocessor 14 receives three consecutive operations which generate error messages 47, the microprocessor 14 will disable operation of the device for two minutes. Any attempt to operate the device in the two minute lockout period will generate an error message 47. An additional feature of the system is a requirement that a digit must be entered within a specified time. Otherwise, the microprocessor 14 will send an error message 47 if there is a five second lapse between keypad entries. A further feature of the system is the modulated voltage across the solenoid 31. When the correct access code is input 53 from the keypad 11, the microprocessor 14 energizes the solenoid 31. The microprocessor 14 must supply sufficient power to the solenoid to unlock the lock (i.e., the solenoid must push the plunger in against the coil to open the lock). This involves two different operations. First, the solenoid 31 must physically push the plunger against the coil. Second, the solenoid 31 must keep the plunger pushed against the coil for the specified time in which to keep the lock unlocked. The first operation (pushing the plunger) is very energy intensive. The solenoid 31 must exert kinetic and potential energy to physically move the plunger against the coil. The second operation (maintaining the position of the plunger) is less energy intensive. The solenoid 31 must exert only potential energy in terms of keeping the plunger compressed against the coil. The device, in order to unlock the lock, supplies the entire battery power necessary for the solenoid 31 to pull the plunger in against the coil. The microprocessor 14 accesses the timer 55, within the microprocessor 14, whereby the timer indicates when to reduce the power. Once the plunger is pulled in, the microprocessor 14 modulates the voltage to the solenoid 31. This reduces the current into the solenoid while the solenoid plunger is held in since the entire DC current is not required to keep the plunger in the closed position relative to the coil. This in turn reduces the total amp-hours of current out of the battery during an access cycle, and the total number of accesses to the device increases. By way of example, the solenoid 31 requires 300 milliamps of current to pull the plunger in. The microprocessor 14 accesses the timer 55, waiting 0.5 seconds to do that operation. The microprocessor 14 then drops the solenoid current to 150 milliamps. This current is sufficient for the solenoid 31 to keep the plunger flush against the coil. The microprocessor 14 accesses the timer 55 again, waiting for the timer 55 to indicate that three seconds have passed, supplying the lower current to allow the user to open the door. In this manner, the microprocessor 14 uses approximately 1/2 as much power in the modulated mode. FIG. 6 highlights another aspect of the invention, the remote operation of the electronic access code device using a battery. The device can be integrated with other electronic devices forming a system of electronic locks. At the center of the system is a central control station whereby each of the devices may be accessed. The accessed device is designed for low power consumption so that it may operate on a battery for an extended period of time. The remote access device is normally in a sleep mode. In other words, the device is not in active operation. The remote device can "wake-up" from the low power sleep mode in a variety of ways. One method is for the circuitry in the sleep mode device to sense the incoming signal. When the signal is sent, the remote device resumes normal operation. Another method is for the circuitry in the sleep mode device periodically to resume normal operation and sense if there is an incoming signal. If the incoming signal is sent, the circuitry is able to receive the bitstream data that contains the access code. The circuitry thus remains in a low-power sleep-mode condition for the majority of the time, dissipating low power, while no signal is received. The device may then be powered by a battery. The remote electronic access code device is divided into two parts: the input electronics 60 and the processing electronics 64. The processing electronics 64 contains a microprocessor, an access code input and output, an acoustic output, light emitting diodes (LED), a voltage regulator, and an electromechanical driver output. Thus, the remote device is similar to the microprocessor in processing the input access code, as shown in FIG. 1, except the access code may be input in several ways. In this embodiment, the data stream is input serially into the microprocessor 14 so that a variety of serial inputs may be connected to the input of the microprocessor 14. For example, the access code may be input using a traditional keypad 11 transmitting data in serial mode. Moreover, the data may be input serially using an electromagnetic signal input from the radio frequency (RF), optical frequency or infrared frequency bands. Thus, the microprocessor 14, in this configuration, may accept the input from any one of this inputs. The input electronics 60 accepts the code sent from the central control. The method of transmitting the code may take several forms including an electromagnetic signal (such as a RF signal sent by an RF serial bitstream transmitter, or an infrared signal) or a data line (telephone line). When an RF signal is used, the central station transmits a signal via a transmit antenna 63 (transducer that sends radiated electromagnetic fields into space). The radiated waves containing the RF signal contains the bitstream access code which is sent to the input electronics 60. The input electronics 60 contains the RF wake-up 61 and the RF decode circuitry 62. In one embodiment, the RF wake-up circuit 61 is ordinarily in a low power sleep-mode. However, for a 10 millisecond period every 1 second, the RF wake-up circuit 61 senses for an RF bitstream signal. If an RF bitstream signal exists, it remains awake and receives the entire RF bitstream signal. The RF wake-up circuit 61 then sends a wake-up enable signal to the RF decode circuit 62. The RF decode circuit 62, via the antenna 63, translates it into a series of bits and then sends the digital bitstream signal to the processing electronics 65 to determine if the digital bitstream signal contains the access code. In another embodiment, the RF wake-up circuit 61 remains in low power sleep mode until it senses the RF signal. The RF signal, in this embodiment, contains a low carrier frequency way and a high frequency RF bitstream superimposed on the low frequency carrier wave. When the RF wake-up circuit 61 senses, via the antenna 66, that there is a signal tuned to the low frequency carrier Wave, the RF wake-up circuit 61 sends a wake-up enable signal to the RF decode circuit 62. The RF decode circuit 62 then accepts the RF bitstream access code signal, and translates it into a series of bits for the microprocessor 14. FIG. 7 shows the schematic of the input electronics 60 wherein the RF wake-up circuit 61 periodically wakes up from a low power sleep mode and senses if there is an incoming RF signal. The RF wake-up circuit 61 consists of two low-power CMOS inverter gates, INV1 and INV2, a CMOS transistor Q3, resistors, and a capacitor. The two inverters INV1 and INV2 are configured in an oscillator configuration in a ratio of 1 to 100. In other words, the oscillator will switch on for {fraction (1/100)} of a second. At this time, the CMOS transistor Q3 will turn on and supply the battery power to the RF decode circuitry 62. The RF decode circuitry 62 will only draw battery power for {fraction (1/100)} of the time, and thus the battery will last 100 times longer than if the battery were permanently connected to the RF decode circuitry 62. The RF decode circuitry 62 consists of two bipolar junction transistors Q1, Q2, two Operational Amplifiers, OP1 and OP2, and resistors, capacitors, inductors and diodes connected to these components. The RF input signal is referred to as an on-off keying of high frequency bursts for set time frames. In the present invention, the frequency is set at 320 MHz. A burst of frequency is detected by the Q1 and Q2 transistors with their circuits tuned to the correct frequency (320 MHz in this example). The RF decode circuitry 62 then senses the data bitstream sent in the form of digital 1 data signal and digital 0 dead band of no frequency. Thus, a train of on and off frequency pulses would be received by the antenna, conditioned and amplified by Q1 and Q2 of the RF decode circuitry 62, and converted to bitstream 1 and 0 digital signals by the two operational amplifier signal conditioners OP1 and OP2. Typically, the operator of the control unit 59 which contains the RF transmitter will enable the RF transmitter with a transmit button 58 to send an RF on-off keying pulse for approximately one second. The RF signal being transmitted is a digital bitstream conditioned to an RF on-off keying signal which takes about two milliseconds in which to transmit one complete signal. The control unit 59 then repeats the signal over and over for the duration that the RF transmitter is enabled. In order for the receiver to detect one complete bitstream from the transmitter, the RF signal only needs to be sampled for two milliseconds during which the transmitter is enabled and transmitting. If the RF transmitter is enabled for one second, the transmitted bitstream signal takes {fraction (1/500)} of a second to be transmitted and is repeated 500 times over the entire one second. The receiver is enabled for {fraction (1/100)} of a second every second, and will have the opportunity to sample and detect a signal that is {fraction (1/500)} of a second in duration, transmitted 500 times over one second. After the {fraction (1/100)} of a second, the oscillator, formed by INV1 and INV2, will switch Q3 off, and the battery power to the RF decode circuitry will be shut off. Only the oscillator circuit (INV1 and INV2) will dissipate battery power at a small rate of less than 100 micro-amps. If less power dissipation by the RF decode circuitry 62 is required, the decode circuitry power duty cycle can be reduced by increasing the oscillator frequency to more than 100 to 1 and thus decreasing the RF decode circuitry 62 sample rate. In order to ensure the RF decode circuitry 62 will be enabled long enough to detect the entire transmitter digital bitstream, the lock CPU would wait for the beginning of the bitstream signal which is received by the RF decode circuitry 62 when the circuitry was enabled and conditioned through OP1, and then would send an output enable signal back to Q3 to override the oscillator and keep the RF decode circuitry 62 enabled with battery power until the lock. CPU has received the correct amount of bitstream data from the transmitter through the decode circuitry. Thereafter, the lock CPU would disable the Q3 transistor and the RF decode circuitry and let the oscillator go back to its low rate of sampling. The processing electronics 64 remains in sleep-mode low current operation until a valid on-off keying frequency signal is received while the RF decode circuitry is enabled and a digital bitstream signal is sent to the lock microprocessor 65. Upon transferring the bitstream signal, the microprocessor 14, within the processing electronics, compares the input code with the access code in the comparator. If correct, the solenoid, DC motor, electromechanical relay, or solid-state relay is activated. After this operation, the microprocessor 14 sends a disable signal to the RF wake-up circuit to assume a low power mode. FIG. 8 shows the schematic of another embodiment of the electronic access control device which also multiplexes the inputs and outputs of the pins of the microprocessor to reduce the number of pins required. The microprocessor 81 used in this embodiment is preferably the MC68HRC705J1A integrated circuit (IC) manufactured by Motorola. As illustrated in FIG. 8, the input devices include a keypad 11 and an electronic key reader 82. In this embodiment, instead of using an EPROM internal of the microprocessor as in the case of the embodiment of FIG. 3, an EEPROM 84 external of the microprocessor 81 is used to store the programmed access code as well as other useful information. The EEPROM 84 used in this embodiment is preferably the 93LC46 IC manufactured by Microchip. Alternatively, a FLASH read-write memory, or any other type of suitable memory, may be used. To effectively use the limited number of pins of the microprocessor 81, the pins are multiplexed such that the keypad 11 and the EEPROM 84 share several communication pins. As illustrated in FIG. 8, pins 16 (PA2), 17(PA1), 18 (PA0) of the microprocessor 81 are connected to pins 4, 3, and 2 of the EEPROM 84, respectively. These pins of the microprocessor 81 are also connected to the keypad 11 for receiving access codes entered by means of the keypad. Pin 3 (PB5) of the microprocessor 81 is connected to pin 1 of the EEPROM. In this configuration, pins 1-4 of the EEPROM 84 are used, respectively, for chip select, data in, data out, and clock. In accordance with an aspect of the present invention, the microprocessor-based control circuit further includes a low-battery detection circuit 68 that does not consume electrical power except when a low-battery detection is in progress. As illustrated in FIG. 8, the access control device is powered by a battery pack 70 which includes one or more batteries. The output of battery pack is connected to a voltage regulator 72 which provides a regulated voltage for operating the control circuit. The low-voltage detection circuit 68 includes a voltage divider 74 which has its input end connected to the output of the battery pack 70 (which in the illustrated case is after an isolating diode 71). The voltage divider 74 is connected in series with a transistor 76 to ground. The base of the transistor 76 is connected (via a resister 77) to pin 6 (PB2) of the microprocessor 81. When Pin 6 of the microprocessor 81 is set high, the transistor 76 is turned on, thereby allowing current to flow through the voltage divider 74. When pin 6 is set low, the transistor 76 is turned off, and the current through the voltage divider is cut off. In that case, the output voltage of the voltage divider 74 will be pulled up to that of the battery voltage minus the voltage drop across the diode 71. The output end of voltage divider 74 is connected to the base of a second transistor 80. The input end of the transistor 80 is connected to the output of the voltage regulator 72, while the output end of the transistor 80 is connected to pin 15 (PA3) of the microprocessor 81. Normally pin 6 of the microprocessor would stay low, and both the transistor 76 and the transistor 80 would be turned off. When a battery voltage test is performed, pin 6 is switched to the high ("1") state to turn on the transistor 76, and the state of pin 15 is sensed by the microprocessor 81 to determine the on/off state of the transistor 80. If the battery voltage is sufficiently high, the output of the voltage divider 74 would be high enough to turn the transistor 80 off. On the other hand, if the battery voltage is low, the output of the voltage divider would be low enough to turn the transistor 80 on, and pin 15 would be switched to the high state. In accordance with an important aspect of the present invention, there is provided an electronic access control device that provides substantially enhanced security and reduced vulnerability to tampering by using two microprocessors. FIG. 9 shows generally the functional block diagram of such a device. As illustrated in FIG. 9, the control device has a first microprocessor 90 and a second microprocessor 92. The first microprocessor 90 is connected to an input device 94 for receiving a user-entered control signal signifying a demand to operate an electronic device 98. The second microprocessor 92 controls a driver circuit 96 for energizing the electrical device 98 to effect a desired operation. The electrical device 98 may be, for example, a solenoid, motor, relay, or the like for opening a lock, or, as will be described in greater detail below, the ignition relay of a motorcycle. The first microprocessor 90 may be positioned close to the input device 94, while the second microprocessor 92 may be located close to the electrical device 98 and is preferably well shielded from external access. The two microprocessors are connected by a two-way communication link 100. As will be described in greater detail below, the user-entered control signal may be, for example, an access code entered using a keypad or electronic key, the operation of an electronic ignition switch controlled by a mechanical lock, or a voice command entered through a voice sensor such as a microphone. Once a user-entered control signal is received, the first microprocessor 90 determines whether the demand to operate the electrical device 98 should be transmitted to the second microprocessor 92. If the demand is to be transmitted, the first microprocessor 90 sends a special communication code to the second microprocessor 92 via the communication link 100. The second microprocessor 92 compares the transmitted communication code with a preset communication code stored in a non-volatile memory 102. If the transmitted code matches the stored code, the second microprocessor 92 activates the driver circuit 96 to energize the electrical device 98. It will be appreciated that this dual-microprocessor configuration significantly reduces the vulnerability of the device to tampering. Even if a tamperer may gain access to the first microprocessor, it is intended that the second microprocessor is well shielded and therefore cannot be reached easily. Since the second microprocessor responses only to a correct communication code, the tamperer will not be able to use the trick of "hot-wiring" to activate the driver circuit 96. Moreover, even if the circuit containing the first microprocessor is somehow replaced by another similar microprocessor circuit for which the correct control signal is already known, that new microprocessor is unlikely to know the communication code specific to the second microprocessor 92. In this way, the two microprocessors function as two individual gate keepers. Even if the first microprocessor could be somehow bypassed, the second microprocessor would not activate the driver circuit without receiving the correct communication code. The microprocessors can also be programmed to implement the "code-hopping" or "rolling-code" scheme used in some existing electronic access control devices to further improve the security of the device. In such a scheme, the preset code stored in the non-volatile memory 102 is used as a seed, and the communication codes stored in the first and second microprocessors are changed as a function of the number of code transmission according to a predefined algorithm based on the seed code. The changes of the communication codes in the two microprocessors are synchronized so that they remain in operative relationship. FIGS. 10A and 10B illustrate an application of the dual-microprocessor configuration in an electronic lock. In this embodiment, the control circuit has two halves connected by a cable. The first half, which is shown in FIG. 10A, contains a first microprocessor 110. The second half, shown in FIG. 10B, contains a second microprocessor 112. Pin 11 (PA7) of the first microprocessor 110 is connected to pin 18 (PA0) of the second microprocessor 112 via the cable 115 and the mating connectors 114 and 116 to establish a two-way serial communication channel between the two microprocessors. The electronic lock has a keypad 11 and an electronic key reader 82 as input devices which are connected to the first microprocessor 110. The second microprocessor 112 controls a energizing circuit 118 for energizing a solenoid 120 to open the lock. When the first microprocessor 110 receives an access code via either the keypad 11 or the key reader 82, it compares the entered access code with an access code stored in its memory. If the entered code matches the stored access code, the first microprocessor 110 transmits a communication code to the second microprocessor 112 via the communication channel described above. The second microprocessor 112 then compares the received communication code with a preset communication code stored in an EEPROM 122. If the two communication codes match, the second microprocessor 112 activates the energizing circuit 118 to energize the solenoid 120 to open the lock. The correct access code and communication code are preferably stored in the EEPROM 122. During initial power-up, i.e., when the battery is first attached to the electronic lock, the second microprocessor 112 transmits the access code and the communication code to the first microprocessor 110, which then stores the codes in its memory (which may be volatile) for subsequent operation. The dual-microprocessor configuration illustrated in FIG. 9 can also be advantageously used in other types of applications. For example, FIG. 11 shows an electronic ignition control system for a motorcycle. In this embodiment, the device contains a first microprocessor 126 and a second microprocessor 128 which are connected by a cable 130. A three-position ignition switch 132 is connected to the first microprocessor 126, which may be located close to the ignition switch. The second microprocessor 128 is connected to an ignition relay 134 and an accessory relay 138, and is preferably disposed close to the ignition mechanism of the motorcycle and well protected from external access. In this arrangement, the ignition switch 132 serves as the input device, and the position of the ignition switch is used as the user-entered control signal. The first microprocessor 126 monitors the switch position. When the ignition switch 132 is turned to the "accessory" position 135, the first microprocessor 126 transmits a communication code together with a switch-position code corresponding to that switch position to the second microprocessor 128. The second microprocessor 128 compares the transmitted communication code with a preset communication code stored in a non-volatile memory 138 which has been programmed at the factory. If the two codes match, the second microprocessor 128 determines from the switch-position code that the switch is set at the accessory position and closes the accessory relay 136. Similarly, when the ignition switch 132 is turned to the "ignition" position 133, the first microprocessor 126 transmits a communication code and a switch-position code corresponding to the ignition position to the second microprocessor 128. The second microprocessor 128 compares the transmitted communication code with the preset communication code. If the two codes match, the second microprocessor 128 determines from the switch-position code that the switch is set at the ignition position and accordingly closes the ignition relay 134 and the accessory relay 136 to start the engine. It will be appreciated that due to this dual-microprocessor arrangement, this ignition control system cannot be "hot-wired" to start the engine of the motorcycle like conventional motorcycle ignition control systems. This system is also not susceptible to tampering by replacing the assembly of the ignition switch 132 and the first microprocessor 126 with another such assembly for which an ignition key has been obtained. FIGS. 12-14 show another advantageous application of the dual-microprocessor configuration of FIG. 9 which utilizes speech recognition to control the operation of an electronic access control device. As illustrated in FIG. 12, the access control device uses a speech recognition microcomputer integrated circuit (IC) 200 to process voice commands given by a user. The speech recognition IC 200 is capable of not only recognizing the commands given but also the voice of the speaker. In other words, the IC is capable of speaker dependent recognition, allowing the user to customize the words to be recognized. Such an IC may be, for example, the RSC-164 microcomputer of Sentry Circuits, Inc. In the embodiment shown in FIG. 12, the speech recognition IC 200 has a microphone 202 connected thereto for receiving voice commands from a user. In this embodiment, the combination of the voice recognition IC 200 and the microphone 202 serves generally the function of the input device 94 of FIG. 9. An optional keypad 11 may also be used for entering an access code. After receiving a voice command, the speech recognition IC 200 analyzes the voice command to recognize the command and the voice pattern of the speaker. If the voice recognition IC 200 recognizes the voice pattern to be that of an authorized user, it transmits a command code corresponding to the command received to the first microprocessor 190. The first microprocessor 190 transmits an operation code corresponding to the command and a communication code stored in its memory to the second microprocessor 192 via a bidirectional communication link 180. The second microprocessor 192 compares the transmitted communication code with a preset communication code which is stored in a non-volatile memory 194. If the two communication codes match, the second microprocessor 192 activates the driver circuit 196 to energize an electrical device 198 to carry out the operation specified by the operation code. FIG. 13 shows another embodiment of the voice controlled access control device. In this embodiment, the voice recognition IC 200, which is a microcomputer in itself, is used to serve the function of the first microprocessor 190 of FIG. 12. Upon receiving a voice command through the microphone 202, the voice recognition IC 200 recognizes the command and analyzes the voice pattern of the speaker. If the voice recognition IC 200 determines that the speaker is an authorized user, it transmits an operation code and a communication code stored in its memory 201 to the second microprocessor 192. If the transmitted communication code matches a preset communication code, the second microprocessor 192 executes the command by activating the driver circuit 196. FIG. 14 shows another embodiment of the voice operated access control device which includes a central control station 220 and one or more remote devices in the arrangement shown generally in FIG. 6. The central control station 220 may be formed as a hand-held remote control unit which can be conveniently carried and handled by the user. For illustration purposes, two remote devices 212A, 212B are shown, each of which has its own unique identification code. The identification codes are stored in the memories 216A, 216B of the microprocessors 228A, 228B of the respective remote devices. The central control station 220 has a voice recognition IC 200 coupled to a microphone 202 for receiving and recognizing a voice command. If the voice pattern of the speaker matches a voice pattern stored in the voice recognition IC 200, the voice recognition IC transmits a command code corresponding to the given command to a central microprocessor 222. The command code may contain a code to indicate which remote device is to be contacted. Alternatively, the determination of which remote device is to be contacted may be made by the central microprocessor according to the command code provided by the voice recognition IC 200. The central microprocessor contains a memory 224 which has the identification codes for the remote devices stored therein. After receiving the command code, the central microprocessor 222 sends out through the transmitter circuit 226 a bitstream signal which contains the identification code of the remote device to be addressed and an operation code indicating the operation to be performed. In the preferred embodiment, the bitstream signal is transmitted at a radio frequency (RF). Other suitable transmission bands may also be used. The remote devices 212A, 212B preferably are normally in the sleep mode and can wake up in the ways described in conjunction with FIG. 6. In the illustrated embodiment, each remote device has a wake-up circuit 230A, 230B and a radio frequency decode circuit 232A, 232B. After receiving the bitstream signal from the central control station 220, the radio frequency decode circuit of each remote device converts the received RF signal into a computer-compatible binary code which includes the identification code and the operation code. Each remote device then compares the received identification code with its own identification code. If the codes match, the remote device carries out the specified operation. This voice-activated remote access control system finds many applications in different settings. For example, as illustrated in FIG. 14, the remote access control device 212A is connected to a file cabinet 240 and a desk 242 in an office for locking and unlocking the cabinet drawers and desk drawers. By way of example, when the user gives the voice command "lock desk," the central control station 220 receives the command through the microphone 202. If the speaker's voice is recognized, the central control station 220 sends out a bitstream signal to cause the remote unit 212A to operate a lock mechanism 241 in the desk 240 to lock the desk drawers. As another example illustrated in FIG. 14, the remote device 212B is used to control a motor 243 in a tool chest 244 to lock and unlock the doors and drawers of the tool chest. In accordance with the object of the present invention to prevent the unauthorized use of electronic keys, there is provided an electronic access control system which has a plurality of remote electronic locks and a master key that has a number of access programmed therein. As illustrated in FIG. 15, the access control system includes a master control device 140 for programming a master access code and the desired number of access into the master key 142. In the illustrated embodiment, the master control device 140 is a personal computer which has an interface device 144, such as a key reader, for communicating with the master key. The master key 142 contains a non-volatile memory which includes an access code storage 146 for storing the master access code specific to the control system, and a counter 148 for storing the number of access allowed. Also shown in FIG. 15 is an electronic lock 150 which can be opened by the master key. The electronic lock has a control circuit based on a microprocessor 151 and a key reader 152 for communicating with the master key. When the master key 142 is presented to the key reader 152, the microprocessor 151 of the electronic lock reads the access code stored in the master key and compares that code to a preset master access code stored in its memory. If the two codes match, the control circuit reads the number of access stored in the master key. If the number of access is one or greater, the microprocessor 151 energizes the solenoid 154 to open the lock 156. In conjunction with the opening of the lock, the microprocessor 151 of the electronic lock 150 decrements the number of access stored in the counter 148 of the master key by one. Thus, if the number of access in the counter 148 is initially set to one, after the opening of the lock the counter is reduced to zero, and the master key cannot be used to open another lock. In this way, by limiting the number of times the master key 142 can be used to open locks, the unauthorized use of the master key is effectively prevented. For instance, in the setting of a hotel, it is necessary to have a mater key for opening the electronic locks installed in the safes in the hotel rooms. If a hotel guest forgets the access code for the safe in his room, the master key can be programmed with the number of access set to one, and used to open that safe. Since the number of access will be reduced to zero after the lock is opened, the master key cannot be subsequently used to open the safe in another room. The use of the master key is thus strictly controlled. In accordance with another aspect of the invention, there is provided an alarm system for a bicycle or a similar manually powered vehicle. As illustrated in FIG. 15, this alarm system includes a remote control 160 mounted in the helmet 162 of the rider of the bicycle 166, and an electronic alarm 164 mounted on the bicycle. The remote control 160 has a transmitter 168 for the wireless transmission of a communication code and other types of control signals to the alarm 164 on the bicycle, which has a receiver 170 for receiving the transmitted signals. In the preferred embodiment, the remote control 160 has a button 172 which when pushed transmits a control signal including the communication code to the alarm 164 on the bicycle to activate or deactivate the alarm. Alternatively, the helmet may be equipped with a keypad for entering an access code by the user. After receiving the access code, the remote control compares the entered access code with a preset access code and transmits the control signals to the electronic alarm on the bicycle when the two access codes match. The alarm 164 includes a motion detector 174 for sensing the movement of the bicycle 166. If movement of the bicycle is detected by the motion detector 174 when the alarm has been activated, the electronic alarm 164 emits audio and/or visual warning signals to deter the potential theft. A timer 176 is included in the electronic alarm 164 to stop the warning signals after a predetermined amount of time has elapsed. This bicycle alarm system which has a remote control 172 mounted in the riding helmet 162 has many advantages. Combining the remote control with the riding helmet provides significant convenience to the rider because there is no need to carry the remote control separately. Moreover, because the remote control is integrated in the helmet of the rider, the rider is less likely to lose or misplace the remote control. Furthermore, because the remote control is required to deactivate the alarm system, combining the remote control with the helmet provides an incentive for the rider to wear the helmet when riding the bicycle. In this way, the bicycle alarm system of the present invention contributes to the safety of the rider and helps the rider to obey the law requiring the bicycle rider to wear a helmet. | <SOH> BACKGROUND OF THE INVENTION <EOH>An electronic access control device, such as an electronic combination lock or an electronic alarm system, allows the user to activate or deactivate the access control without the use of the conventional key and mechanical lock mechanism. With the development of microprocessor integrated circuits, it is becoming common to implement microprocessor-based control circuitry in electronic access control devices. Electronic access control devices are known, for example, from U.S. Pat. No. 5,021,776. In this device, and other common electronic access control devices, a microprocessor is used in combination with a keypad and an electrically programmable read only memory (EPROM). The microprocessor compares the combination entered in the keypad by the operator with the combination stored in the EPROM. If the two combinations match, the microprocessor opens the lock. There are problems associated with previous electronic access control devices. One area of problems concerns the manufacture of the devices, including the difficulty in programming the non-volatile memory, such as the EPROM, for storing the access code and other useful information for the operation of the device. EPROMs, which usually require parallel programming, interrupt the manufacturing process in that they restrict when the manufacturer can program the device. A manufacturer would prefer to program the access code into the EPROM as the last step in the manufacturing process. However, with parallel EPROMs, burning in the code after the device has manufactured is difficult. After the device is soldered together, the manufacturer must contend with integrated circuit pin clips and must worry about interference with other circuitry on the manufactured device. Further, manufacturing, with known electronic access control devices, requires many pin connections which increase manufacturing cost. Related to the problems associated with the pin connections of the microprocessor integrated circuit (IC) is the concern of device reliability and ease of use. When the device contains a significant number of pin connections, the reliability of the device decreases. Further, serial access to the EPROM to determine the electronic access code is easier than parallel access in terms of pin connections. When the user forgets or loses the access code in the EPROM, a locksmith could plug into the device and retrieve the access code serially without breaking into the safe. However, with parallel EPROMs, serial access is not available. One common problem associated with previous electronic locks is their potential vulnerability to tampering. A conventional electronic lock receives an access code via an input device such as a keypad or electronic key reader, verifies the access code, and then energizes a solenoid, relay, motor, or the like to open the lock. This arrangement is vulnerable to tampering because if the control circuit is somehow broken in or removed, one can open the lock by "hot-wiring" the control lines for activating the lock-opening mechanism. Another technically challenging problem is related to the need to provide electrical energy to power the operation of the electronic access control device. For many applications, it is desirable to use a portable energy source, such as a battery, to power the access control device. A battery, however, has a rather limited amount of electrical energy stored therein. Thus, it is extremely important to reduce the power consumption of the control circuit and peripheral devices of the access control device to extend the service life of the batteries. For instance, it is typical to use a solenoid-operated lock in an electronic lock. The power consumed by the solenoid in opening the lock is quite significant. Thus, the battery can be rapidly drained by the repeated operation of the solenoid. As another example, it is common to include a low-battery detection circuit in an electronic lock to provide a warning signal to the user when the battery voltage falls below a predetermined level. The operation of the low-battery detection circuit, however, also consumes electrical energy and contributes to the draining of the battery. Some electronic locks are provided with electronic keys. When an electronic key is presented to a key reader of an associated electronic lock, it transmits an access code to the electronic lock. By using an electronic key, the user does not have to enter manually the access code by means of a keypad. In certain applications, a remote control unit is used which has a radio transmitter to send the access code to the lock without direct electrical contact with the electronic lock. Although electronic keys are a convenient feature, they have their associated problems. One problem is related to the unauthorized use of the keys. For example, many hotels provide safes equipped with electronic locks in their hotel rooms. Such safes typically allow the hotel guests to set their own access codes. In cases where the hotel guests forget the access codes they set, the hotel management has to send someone with a master key which has a master access code stored therein to open the safes. There is a danger that such a master key may be used for unauthorized opening of other safes in the hotel. Another problem associated with the use of an electronic key or a wireless access code transmitter is that the key or the transmitter may be lost easily, or the user may simply forget to bring the key or transmitter. This problem is especially serious if the electronic access control device does not provide other means, such as a keypad, for entering the access code. | <SOH> SUMMARY OF THE INVENTION <EOH>It is a general object of the present invention to develop an electronic access control device which is easier to manufacture and more reliable to operate, and provides improved security to prevent tampering or unauthorized access. It is an object of the present invention to provide an electronic access control device with a non-volatile memory for storing an access code that permits the manufacturer of the device to easily insert the access code into the device and then read out the code for verification. It is an object of the present invention to provide an electronic access control device that provides significantly enhanced security and reduced vulnerability to tampering as compared to previous electronic locks. It is an object of the present invention to develop an electronic access control device which has fewer total components and pin connections for smaller device area and greater reliability. It is another object of the present invention to develop an electronic access control device with a solenoid-operated lock which has reduced power consumption by reducing the power used in operating the solenoid. It is a related object of the present invention to develop an electronic access control device that has an improved low-battery detection circuit which has minimized energy consumption. It is a more specific object of the present invention to provide an electronic alarm system for a bicycle that uses a wireless transmitter for sending an access code for activating and deactivating the alarm system and that is configured to help the rider of the vehicle to prevent losing the transmitter or forgetting to bring the transmitter. It is another more specific object of the present invention to provide an electronic access control system with a master key for a plurality of remote electronic locks that effectively prevents the unauthorized use of the master key. The present invention accomplishes these and other objects and overcomes the drawbacks of the prior art. First, there is provided an electronic access control device which reduces the number of pin connections required to manufacture, to read, to program, and to operate the device. The device multiplexes the inputs and outputs of the microprocessor IC so that a single pin can function as an input in one mode and an output in another. The microprocessor determines, based on the mode of operation, whether a pin functions as an input or an output. The electronic access control device of the present invention has a communication port connected to selected pins of the microprocessor IC for accessing the non-volatile memory for storing an access code. Through the communication port, the manufacturer can interact with the microprocessor to store an access code into the non-volatile memory and retrieve the access code for verification. By virtue of the provision of the communication port, the factory-programmed access code can be saved into the non-volatile memory after the control circuitry is completely assembled. In one embodiment, the electronic access control device has a microprocessor IC with a plurality of pins, a keypad for inputting user-entered access codes and a non-volatile memory, such as an EEPROM, external of the microprocessor for storing an access code. At least one of the IC pins is connected to both the keypad and the non-volatile memory for receiving the user-entered code from the keypad and transferring data between the IC and the memory. In accordance with the object of the invention to reduce the vulnerability to tampering, the present invention provides an electronic access control device which has two microprocessors. The first microprocessor is preferably disposed close to the user interface such as a keypad or an electronic key reader. The second microprocessor is preferably disposed close to the lock mechanism and substantially shielded from external access. When the first microprocessor receives a user-entered code, it compares the entered code to a stored access code. If those two codes match, the first microprocessor transmits a special communication code to the second microprocessor. The second IC opens the lock if the transmitted communication code matches a stored communication code. Since the second IC is well protected from external access, the risk of tampering by hard-wiring is significantly reduced. This dual-microprocessor arrangement is advantageously used in a voice activated access control system which has a first microprocessor circuit having speech recognition capability, and a second microprocessor circuit which carries out a commanded operation when receiving a correct communication code from the first microprocessor circuit. The first microprocessor circuit may include a transmitter for wireless transmission of the communication code. The dual-microprocessor arrangement is also advantageously used in a motorcycle ignition switch control system for turning on accessories or starting the engine in response to the ignition key position. The present invention also provides an effective solution to the problem associated with the intensive need for power of the solenoid. In the present invention, the electronic access control device pulses the power to the solenoid so that the overall power consumption in operating the solenoid is lower. Thus, the battery has a longer life and the lock has an increased number of accesses. In accordance with a related aspect of the present invention, the electronic access control device employs a low-battery detection circuit that is turned off and therefore consumes no electrical power when the microprocessor is in the sleep mode. The low-battery detection circuit uses a combination of a voltage divider and a transistor to compare the battery voltage and the regulated voltage for determining whether the battery voltage is low, and uses another transistor in series with the voltage divider to selectively turn the current through the voltage divider on and off. When the current through the voltage divider is off, the low-voltage detection circuit does not consume electrical energy. In the case of an electronic access control system with a master key and a plurality of remote electronic locks, the present invention effectively prevents unauthorized use of the master key. In accordance with the present invention, the master key has a master access code and a number of access stored therein. Each of the remote electronic lock has a key reader to communicating with the master key. When an electronic lock detects in the key a correct master access code and a number of access that is at least one, it opens the associated lock and decrements the number of access in the key by one. In accordance with another aspect of the present invention, there is provided an electronic alarm system for a bicycle or a similar manually powered vehicle. The alarm system includes a remote control unit installed in the helmet of the rider of the bicycle, and an electronic alarm installed on the bicycle. The remote control unit has a transmitter for the wireless transmission of control signals to activate or deactivate the alarm on the bicycle. The alarm on the bicycle includes a motion detector for sensing the movement of the bicycle. If the motion detector detects the movement of the vehicle when the electronic alarm is activated, the alarm is set off. It is a feature of the present invention to mount the remote control in the helmet of the rider of the bicycle. By virtue of this arrangement, the rider is more likely to remember to wear the helmet. The risk of losing the remote control is also substantially eliminated. These and other features and advantages of the invention will be more readily apparent upon reading the following description of the preferred embodiment of the invention and upon reference to the accompanying drawings wherein. | 20040707 | 20060328 | 20050414 | 99690.0 | 7 | ZIMMERMAN, BRIAN A | ELECTRONIC ACCES CONTROL DEVICE | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,885,985 | ACCEPTED | Durable hydrophobic surface coatings using silicone resins | A hydrophobic coating including solid silsesquioxane silicone resins to increase durability is provided. The hydrophobic coating is any composition that increases the contact angle to a surface, preferably glass. The durability of the hydrophobic coating is preferably increased to one and a half years, more preferably three years. | 1. A durable water repellent composition for surfaces comprising: a curing agent; and a silsesquioxane silicone resin. 2. The composition of claim 1 wherein the amount of silicone resin is in the range of from about 0.1 to about 5 wt %. 3. The composition of claim 1 wherein the surface is glass, silica, alumina, or surfaces with a high oxygen content. 4. The composition of claim 1 wherein the surface is an aircraft windshield. 5. The composition of claim 1 wherein the curing agent is a C16-C18 alkoxysilane. 6. The composition of claim 1 wherein the silicone resin has a cubic structure. 7. The composition of claim 1 wherein the silicone resin is an MQ resin. 8. The composition of claim 1 wherein the silicone resin has a molecular weight in the range of about 5,000 to about 15,000. 9. The composition of claim 1 further comprising a solvent. 10. The composition of claim 1 further comprising a catalyst. 11. The composition of claim 1 further comprising one or more additives. 12. The composition of claim 1 further comprising a solvent, a catalyst and one or more additives. 13. The composition of claim 1 wherein the curing agent and the silsesquioxane silicone resin is at least in part crosslinked. 14. The composition of claim 13 wherein the amount of silicone resin is in the range of from about 0.1 to about 5 wt %. 15. The composition of claim 13 wherein the surface is glass, silica, alumina, or surfaces with a high oxygen content. 16. The composition of claim 13 wherein the surface is an aircraft windshield. 17. The composition of claim 13 wherein the curing agent is a C16-C18 alkoxysilane. 18. The composition of claim 13 wherein the silicone resin has a cubic structure. 19. The composition of claim 13 wherein the silicone resin is an MQ resin. 20. The composition of claim 13 wherein the silicone resin has a molecular weight in the range of about 5,000 to about 15,000. 21. The composition of claim 13 further comprising a solvent. 22. The composition of claim 13 further comprising a catalyst. 23. The composition of claim 13 further comprising one or more additives. 24. The composition of claim 13 further comprising a solvent, a catalyst and one or more additives. 25. An article comprising a glass substrate of which at least a portion of the substrate is treated with a durable water repellant composition comprising: a curing agent; and a silsesquioxane silicone resin. 26. The article of claim 25 further comprising a primer layer. 27. The article of claim 25 further comprising a topcoat layer. 28. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 2. 29. The article of claim 28 further comprising a primer layer. 30. The article of claim 28 further comprising a topcoat layer. 31. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 3. 32. The article of claim 31 further comprising a primer layer. 33. The article of claim 31 further comprising a topcoat layer. 34. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 5. 35. The article of claim 34 further comprising a primer layer. 36. The article of claim 34 further comprising a topcoat layer. 37. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 6. 38. The article of claim 37 further comprising a primer layer. 39. The article of claim 37 further comprising a topcoat layer. 40. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 7. 41. The article of claim 40 further comprising a primer layer. 42. The article of claim 40 further comprising a topcoat layer. 43. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 8. 44. The article of claim 43 further comprising a primer layer. 45. The article of claim 43 further comprising a topcoat layer. 46. An article comprising a glass substrate of which at least a portion of the substrate is treated with a durable water repellant composition comprising: a curing agent; and a silsesquioxane silicone resin; said curing agent and silsesquioxane silicone resin is at least in part crosslinked. 47. The article of claim 46 further comprising a primer layer. 48. The article of claim 46 further comprising a topcoat layer. 49. The composition of claim 2 wherein the curing agent is a C16-C18 alkoxysilane. 50. The composition of claim 49 wherein the curing agent and the silsesquioxane silicone resin is crosslinked. 51. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 14. 52. The article of claim 51 further comprising a primer layer. 53. The article of claim 51 further comprising a topcoat layer. 54. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 15. 55. The article of claim 54 further comprising a primer layer. 56. The article of claim 54 further comprising a topcoat layer. 57. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 16. 58. The article of claim 57 further comprising a primer layer. 59. The article of claim 57 further comprising a topcoat layer. 60. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 17. 61. The article of claim 60 further comprising a primer layer. 62. The article of claim 60 further comprising a topcoat layer. 63. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 18. 64. The article of claim 63 further comprising a primer layer. 65. The article of claim 63 further comprising a topcoat layer. 66. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 19. 67. The article of claim 66 further comprising a primer layer. 68. The article of claim 66 further comprising a topcoat layer. 69. An article comprising a glass substrate of which at least a portion of the substrate is treated with the composition of claim 20. 70. The article of claim 69 further comprising a primer layer. 71. The article of claim 69 further comprising a topcoat layer. 72. A method of making a hydrophobic surface comprising applying a water repellant composition to the surface of a substrate, wherein the water repellant composition comprises a curing agent and a silsesquioxane silicone resin. 73. The method of claim 72 wherein applying the water repellant composition comprises using a sponge or the like. 74. The method of claim 72 wherein applying the water repellant composition comprises spraying the surface with the composition and then spreading the composition with a sponge or a cloth. 75. The method of claim 72 wherein the amount of silicone resin in the range of from about 0.1 to about 5 wt %. 76. The method of claim 72 wherein the surface is glass, silica, alumina, or surfaces with a high oxygen content. 77. The method of claim 72 wherein the surface is an aircraft windshield. 78. The method of claim 72 wherein the curing agent is a C16-C18 alkoxysilane. 79. The method of claim 72 wherein the silicone resin has a cubic structure. 80. The method of claim 72 wherein the silicone resin is an MQ resin. 81. The method of claim 72 wherein the silicone resin has a molecular weight in the range of about 5,000 to about 15,000. 82. The method of claim 72 wherein the water repellant composition further comprises a solvent. 83. The method of claim 72 wherein the water repellant composition further comprises a catalyst. 84. The method of claim 72 wherein the water repellant composition further comprises one or more additives. 85. The composition of claim 72 wherein the water repellant composition further comprises a solvent, a catalyst and one or more additives. 86. The method of claim 72 wherein the water repellant composition further comprises crosslinking the curing agent. | This application claims the benefit of U.S. Provisional Application No. 60/485,698 filed Jul. 9, 2003, the entire disclosure of which is hereby incorporated by reference. FIELD OF THE INVENTION The invention relates to the art of surface treatment and more particularly to the art of producing a durable hydrophobic surface. BACKGROUND OF THE INVENTION Hydrophobic coatings for glass surfaces are known using traditional silane chemistry. When a glass surface is provided with a hydrophobic coating and the glass is used for a windshield or side window of an automobile, the driver's visual field is secured. Typically, an alkoxylated silane is allowed to react with the glass surface, thereby attaching the coating material to the substrate. Unfortunately, the inherent disadvantage to this approach is that the resulting silicone bond (Si—O—Si) is vulnerable to hydrolysis. Methods to minimize the hydrolysis include increasing the packing density of the material on the surface. This causes steric effects to aid in the prevention of water reaching the reaction site, thereby preventing hydrolysis. These hydrophobic coatings provide improved visibility when used on automobile window glass. However, these coatings have a tendency to wear off within a few months. The problems of hydrophobic coatings also extend to the airline industry. The current coating technologies are inadequate because of their limited durability. Technologies for improving the visibility in aircraft under rainy conditions include “jet blast” and windshield wipers. Windshield wiper systems further include hydrophobic coatings for greater effectiveness. The “jet blast” system involves blanketing the surface of the windshield with a blanket of high velocity air. However, there is still a need for a more durable coating that will last for more than a year and significantly improve the pilot's visual field during inclement weather. The above water-repellent glass is generally produced by a wet-coating method in which a water-repellent agent containing an organic silicon compound, typified by a polydimethylsiloxane compound or a fluorine-containing silicon compound, is wet-coated on a glass surface, or by a dry-coating method in which the above water-repellent agent is dry-coated by means of plasma or vapor deposition. However, in the above methods of coating the water-repellent agent directly on a glass surface, it is difficult to maintain water repellency for a long time, since the adhesion strength between the water-repellent agent and the glass is low. The non-wettability of a substrate, more commonly referred to as its hydrophobic/oleophobic property, consists in the fact that the contact angles between a liquid and this substrate are high, for example at least about 60° for water. The liquid therefore tends to flow readily over the substrate, in the form of drops, simply under gravity if the substrate slopes, or under the effect of aerodynamic forces in the case of a moving vehicle. Examples of agents which are known to impart this hydrophobic/oleophobic property are fluorinated alkylsilanes as described in U.S. Pat. Nos. 5,571,622; 5,324,566; and 5,571,622 which are hereby incorporated by reference in their entirety. According to these patents, this layer is obtained by a solution containing fluorinated organosilanes in a non-aqueous organic solvent is applied to the surface of a substrate. Preferred non-aqueous organic solvents include n-hexadecane, toluene, xylene, etc. These solvents are particularly suitable for a fluorinated chlorosilane. It is also possible to use a methyl or ethyl alcohol as solvent when the fluorinated silane is a fluorinated alkoxysilane. The hydrophobic coating includes hydrolyzable fluorinated alkylsilanes. They are preferably of the monomolecular type obtained from at least one fluorinated alkylsilane whose carbon chain, which may be branched, comprises at least six carbon atoms, with the carbon of the extremity (extremities) being entirely substituted by fluorine. The layer can also be obtained from fluorinated alkylsilanes or from a mixture of fluorinated alkylsilanes and, possibly, a mixture of fluorinated alkylsilanes and silanes of the SiX4 type in which X is a hydrolyzable group. The current hydrophobic coatings also have environmental and safety issues. The coating may involve the application of perfluoro alkyl silanes in a halogenated hydrocarbon solvent. Current coatings also employ cationic quaternary ammonium compounds and silico-titanium copolymers. For the foregoing reasons, there is a need for a more durable hydrophobic coating, preferably with a contact angle of at least about 90°, more preferably 100° capable of maintaining acceptable contact angles for at least about 1.5 years. This minimum is extended to about 3 years if the coating is not easily replaceable. SUMMARY OF THE INVENTION Embodiments of the invention fulfill the aforementioned need in one or more of the following aspects. In one aspect, the invention relates to a durable water repellent composition for surfaces which comprises a curing agent and a silicone resin. The silicone resin is preferably a silsesquioxane silicone resin. In some embodiments, the curing agent is a C16-C18 alkoxysilane and the silicone resin is an MQ resin. In other aspects of the invention, the invention relates to an article comprising a glass substrate of which at least a portion of the substrate is treated with the durable water repellent composition discussed above. In some embodiments, the curing agent and the silicone resin is at least in part crosslinked. In some embodiments, the article may further include a primer layer, a topcoat layer, or both. Additional aspects of the invention and characteristics and properties of various embodiments of the invention become apparent with the following description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of a ladder type silsesquioxane. FIG. 2 is a schematic representation of a T8 cube type silsesquioxane. FIG. 3 is a schematic representation of a cage type silsesquioxane. DESCRIPTION OF EMBODIMENTS OF THE INVENTION In the following description, all numbers disclosed herein are approximate values, regardless whether the word “about” or “approximate” is used in connection therewith. They may vary by 1 percent, 2 percent, 5 percent, or, sometimes, 10 to 20 percent. Whenever a numerical range with a lower limit, RL and an upper limit, RU, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R═RL+k*(RU−RL), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Embodiments of the invention provide a hydrophobic coating having improved durability of rain and soil repellency on glass and/or glass-like surfaces through the addition of a solid silicone resin to the hydrophobic coating. The hydrophobic coating comprises a curing agent. Other embodiments include surface preparation, a primer layer, and crosslinking the hydrophobic coating. In some embodiments, the hydrophobic coating is not crosslinked. Hydrophobic coatings comprise any composition which increases the water repellency of the surface it is applied to. Without being bound by any particular theory, the coating is obtained through reaction of a curing agent with reactive groups on the surface of the substrate, forming a covalent bond. Curing agents which increase the repellency include alkyl polysiloxanes, perfluoroalkyl silanes, fluorinated olefin telomers, organosilanes, and modified organic silicone oils. These components are described in U.S. Pat. Nos. 3,579,540; 4,983,459; 5,071,709; 5,328,768; 5,425,804; 5,800,918; 5,889,086; 5,997,943; and 6,340,502, all of which are herein incorporated by reference in their entirety. The overall structure of the layer is, for an organosilane, covalent bonding at the point of fixation on the surface of the substrate, and one or two covalent bonds with neighboring organosilane molecules, through other hydrolyzable moieties. The thickness of the layer obtained ranges from about 5 to about 1000 angstroms, preferably about 10 to about 100 angstroms. The layer preferably does not impair the transparency of, or vision through, the substrate. Curing agents also include organic silicon compounds and/or organic fluorine compounds. The organic silicone compounds which may be used as a hydrophobic coating include low molecular weight polysiloxanes, chlorosilane compounds, alkoxysilane compounds, silazane compounds and agents composed mainly of these compounds. These compounds may be used in various combinations. Examples of polysiloxanes include a linear, branched or cyclic polydimethylsiloxane; polysiloxanes having a hydroxyl group in the molecular chain such as silanol-terminated polydimethylsiloxane, silanol-terminated polydiphenylsiloxane, diphenylsilanol-terminated polydimethylphenylsiloxane, carbinol-terminated polydimethylsiloxane, hydroxypropyl-terminated polydimethylsiloxane and polydimethyl-hydroxyalkylene oxide methylsiloxane; polysiloxanes having an amino group in the molecular chain such as bis (aminopropyldimethyl)siloxane, aminopropyl-terminated polydimethylsiloxane, aminoalkyl group-containing, T-structured polydimethylsiloxane, dimethylamino-terminated polydimethylsiloxane and bis(aminopropyldimethyl)siloxane; polysiloxanes having a glycidoxyalkyl group in the molecular chain such as glycidoxypropyl-terminated polydimethylsiloxane, glycidoxypropyl-containing, T-structured polydimethylsiloxane, polyglycidoxypropylmethylsiloxane and a polyglycidoxypropylmethyldimethylsiloxane copolymer; polysiloxanes having a chlorine atom in the molecular chain such as chloromethyl-terminated polydimethylsiloxane, chloropropyl-terminated polydimethylsiloxane, polydimethyl-chloropropylmethylsiloxane, chloro-terminated polydimethylsiloxane and 1,3-bis (chloromethyl)tetramethyldisiloxane; polysiloxanes having a methacryloxyalkyl group in the molecular chain such as methacryloxypropyl-terminated polydimethylsiloxane, methacryloxypropyl-containing, T-structured polydimethylsiloxane and polydimethyl-methacryloxypropylmethylsiloxane; polysiloxanes having a mercaptoalkyl group in the molecular chain such as mercaptopropyl-terminated polydimethylsiloxane, polymercaptopropylmethylsiloxane and mercaptopropyl-containing, T-structured polydimethylsiloxane; polysiloxanes having an alkoxy group in the molecular chain such as ethoxy-terminated polydimethylsiloxane, polydimethylsiloxane having trimethoxysilyl on one terminal and a polydimethyloctyloxymethylsiloxane copolymer; polysiloxanes having a carboxyalkyl group in the molecular chain such as carboxylpropyl-terminated polydimethylsiloxane, carboxylpropyl-containing, T-structured polydimethylsiloxane and carboxylpropyl-terminated, T-structured polydimethylsiloxane; polysiloxanes having a vinyl group in the molecular chain such as vinyl-terminated polydimethylsiloxane, tetramethyldivinyldisiloxane, methylphenylvinyl-terminated polydimethylsiloxane, a vinyl-terminated polydimethyl-polyphenylsiloxane copolymer, a vinyl-terminated polydimethyl-polydiphenylsiloxane copolymer, a polydimethyl-polymethylvinylsiloxane copolymer, methyldivinyl-terminated polydimethylsiloxane, a vinyl terminated polydimethylmethylvinylsiloxane copolymer, vinyl-containing, T-structured polydimethylsiloxane, vinyl-terminated polymethylphenetylsiloxane and cyclic vinylmethylsiloxane; polysiloxanes having a phenyl group in the molecular chain such as a polydimethyl-diphenylsiloxane copolymer, a polydimethyl-phenylmethylsiloxane copolymer, polymethylphenylsiloxane, a polymethylphenyl-diphenylsiloxane copolymer, a polydimethylsiloxane-trimethylsiloxane copolymer, a polydimethyl-tetrachlorophenylsiloxane copolymer and tetraphenyldimethylsiloxane; polysiloxanes having a cyanoalkyl group in the molecular chain such as polybis(cyanopropyl)siloxane, polycyanopropylmethylsiloxane, a polycyanopropyl-dimethylsiloxane copolymer and a polycyanopropylmethyl-methyphenylsiloxane copolymer; polysiloxanes having a long-chain alkyl group in the molecular chain such as polymethylethylsiloxane, polymethyloctylsiloxane, polymethyloctadecylsiloxane, a polymethyldecyl-diphenylsiloxane copolymer and a polymethylphenetylsiloxane-methylhexylsiloxane copolymer; polysiloxanes having a fluoroalkyl group in the molecular chain such as polymethyl-3,3,3-trifluoropropylsiloxane and polymethyl-1,1,2,2-tetrahydrofluorooctylsiloxane; polysiloxanes having a hydrogen atom in the molecular chain such as hydrogen-terminated polydimethylsiloxane, polymethylhydrosiloxane and tetramethyldisiloxane; hexamethyldisiloxane; and a polydimethylsiloxane-alkylene oxide copolymer. Many polysiloxanes are commercially available as water repellents, such as Super Rain X formed mainly of polydimethylsiloxane (supplied by Unelko) and Glass Clad 6C formed mainly of polydimethylsiloxane whose terminal groups are replaced with chlorine atom (supplied by Petrarch Systems Inc.). For adhesion to a porous silica layer, it is advantageous to use polysiloxanes having functional groups which easily physically or chemically bond to a hydroxyl group on the silica surface, such as alkoxy, hydroxyl and amino groups. The above polysiloxanes may be used alone or in combination. Chlorosilane compounds and alkoxysilane compounds have the following formula: R1m—Si—R2n wherein R1 is an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group or an alkyl or a group containing fluoroalkyl in combination with a —O—, CO2—, SO2N(C3H7) or —CONH—, R2 is chlorine or an alkoxy group having 1 to 6 carbon atoms, m is 1, 2 or 3, and n is 1, 2 or 3, provided that m+n=4. Typical examples of the chlorosilane compound and alkoxysilane compound include C18H37 SiCl3, C18H37 Si(OCH3)3, C12H25 SiCl3, C12H25 Si(OCH3)3, CF3(CF2)7 CH2CH2Si(OCH3)3, CF3(CF2)7CH2CH2SiCl3, CF3(CF2)5CH2CH2SiCl3, CF3(CF2)5CH2CH2Si(OCH3)3, CF3CH2CH2SiCl3, CF3CH2CH2Si(OCH3)3, C8F17SO2N(C3H7)CH2CH2CH2Si(OCH3)3, C7F15CONHCH2CH2CH2Si( )CH3)3, C88F17CO2CH2CH2CH2Si(OCH3)3, C8F17—O—CF(CF3)CF2—O—C3H6SiCl3 and C3F7—O—CF(CF3)CF2—O)2—CF(CF3)CONH—CH2)3Si(OCH3)3. These compounds may be used as a mixture, or may be preliminarily converted to partial hydrolysis condensates with an acid or an alkali before use. In a preferred embodiment, the alkoxysilane comprises from 16 to 18 carbon atoms. Typical examples of the silazane compound include hexamethyldisilazane and CF3(CF2)7CH2CH2Si(NH)3/2. These may be used as a mixture, or may be preliminarily converted to partial hydrolysis condensates with an acid or an alkali before use. The fluorinated alkylsilane is preferably a perfluoroalkylsilane with the general formula: CF3—(CF2)n—(CH2)m—SiX3 in which: n is 0 to 12; m is 2 to 5; X is a hydrolyzable group, for example, a chlorinated group or alkoxy group. Preferably, the perfluoroalkylsilane is selected from the group: CF3—(CF2)5—(CH2)2—SiCl3, CF3—(CF2)7—(CH2)2—SiCl3, CF3—(CF2)9—(CH2)2—SiCl3. To increase the durability of the coatings, solid silicone resins having a low molecular weight have been added to various curing agents such as described above. The silicone resins are solid at ambient temperatures, preferably in a powder form. The molecular weight of the resins is preferably from about 5,000 to about 15,000, more preferably from about 8,000 to about 10,000. The amount of silicone resins in the hydrophobic composition ranges from about 0.25 to about 4 wt %, preferably from about 0.5 to about 2 wt %, more preferably from about 0.75 to about 1.5 wt %. The silicone resins are preferably silsesquioxane silicone resin (polysilsesquioxanes). Silsesquioxane silicone resin, or T-resins, are a class of compounds with the empirical formula RSiO1.5. These compounds derive their name from the one and one half (1.5) stoichiometry of oxygen bound to silicon, with the alternate name “T-resin” derived from the presence of three oxygen substituents on silicon (tri-substituted). Several structural representations of silsesquioxanes with the empirical formula RSiO1.5 are possible, with the two most common representations being a ladder-type structure, see FIG. 1, and a cubic structure, see FIG. 2 containing eight silicon atoms placed at the vertices of the cube. The ladder-type structure is a two dimensional oligomeric silicon-oxygen structure. The cubic structure has discrete molecular clusters of silicon and oxygen having capping terminations on the open coordination sites of the silicon atom. The cubic structure is more accurately represented by a cage structure, see FIG. 3. Some cubic cases comprise a square prismatic arrangement of silicon atoms linked through oxygen atoms. Other sites are terminated by any suitable capping ligand group, such as an alkyl or alkoxy group. The silicone resin may have a ladder-type structure, a T8 cube structure, or a cage structure. In a preferred embodiment, the resin is a T-resin having a three dimensional structure. In a more preferred embodiment, the resin is a product of the cohydrolysis of tetraalkoxysilane and trimethylethoxysilane, commonly known as an MQ resin. The chemcial structure of the MQ resin is a three dimensional network of polysilicic units terminated with trimethylsilyl groups. In a preferred embodiment, the durable water repellant coating employed in the present invention are the products of the hydrolysis and condensation of at least one alkyltrialkoxysilane having the structure R1—Si—(OR)3 wherein R is an alkyl group containing 1 to about 4 carbon atoms, and R1 is an aliphatic, cycloaliphatic, or aromatic group containing 1 to about 12 carbon atoms. Groups represented by R1 can include substituent or connective moieties such as ethers, amides, esters, arylene, and the like. Preferably, however, R1 is selected from the group consisting of alkyl or fluoroalkyl containing 1 to about 12 carbon atoms, cycloalkyl containing 5 to about 12 carbon atoms, and aryl containing 6 to about 12 carbon atoms. More preferable R1 groups are alkyl groups containing 1 to about 3 carbon atoms, methyl being particularly preferred. Polysilsesquioxanes, which are generally prepared by the hydrolysis and condensation of methyltrimethoxysilane (Scheme 1, R═—CH3), are commercially available from various sources including Wacker-Chemie GmbH (Munich, Germany). Substituents on silicon can include hydrogen, alkyl, alkenyl, alkoxy and aryl. Due to organic substitution on silicon, many silsesquioxanes have reasonable solubility in common organic solvents. The silicone resin is preferably an alkyl poly-silsesquioxane, a poly-siloxane modified with a cyanoalkyl or carbinol group and, a poly-silicate. These materials are very soluble in aqueous liquids. The polysiloxane contains covalently bonded reactive functionalities suitable for polymerization or grafting silsesquioxanes to polymer chains. The polysiloxane contains nonreactive organic functionalities for solubility and compatibility of the polysiloxane with various polymer systems. In some embodiments, the polysiloxane does not incorporate an oxide. In the present invention, the above silicone compound and/or the above organic fluorine compound may be used with a solvent, an adhesion promoter, a curing agent and a curing catalyst as required. In some embodiments, the coating composition is substantially free of colloidal silica. In some embodiments, the coating composition is substantially free of polybutylene. In some embodiments, the coating composition is substantially free of alkyd resin. The solvent is one that can dissolve the above silicone compound and/or the above organic fluorine compound and can be uniformly applied to a substrate. The solvent is generally selected from fluorine-containing solvents, aliphatic or aromatic solvents, ketones and esters. The adhesion promoter for improving the adhesion of the porous silica surface to the above silicone compound and/or the above organic fluorine compound is not always required. The adhesion promoter can therefore be selected depending upon use. Typical examples of the adhesion promoter include silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, tetramethoxysilane and γ-aminopropyltrimethoxysilane. A solution based on a fluorinated alkylsilane or a mixture of fluorinated alkylsilanes and, optionally, other silanes in a nonpolar solvent system may be used as the hydrophobic coating. The solution comprises an alkylsilane of the type described above, whose concentration varies from about 2×10−3 to about 5×10−2 mol/L in a nonpolar solvent system. The choice of solvent is not indifferent and has an influence on the proportion of alkylsilanes grafted onto the substrate. The solvent system consists of at least about 80 vol % of a nonpolar solvent and about 20% of a chlorinated solvent(s). The nonpolar solvent comprises, preferably, a carbon chain whose length is on the same order of magnitude as that of the organosilane used. In other words, the number of carbons of the solvent is overall identical, to the nearest two or three carbons, to the number of carbons present in the carbon chain of the organosilane. The nonpolar solvent is, preferably, selected from n-hexadecane or isooctane, the chlorinated solvent is preferably selected from the group comprising dichloromethane, trichloromethane, trichloroethane, trichloroethylene, trichlorotrifluoroethane, and carbon tetrachloride. The organic fluorine compounds used are largely classified into compounds having a low molecular weight or a polymer or oligomer compound. Suitable compounds having low molecular weight include fluoroalkyl alcohols, fluoroalkylcarboxylic acids and fluoroalkylamines in addition to the above organic fluorine-containing silicone compounds. Suitable polymers and oligomers include polytetrafluoroethylene, polytrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polyperfluoroalkyl vinyl ether, polyperfluoropropylene, a polytetrafluoroethylene-perfluoropropylene copolymer, a polytetrafluoroethylene-ethylene copolymer and a polyvinyl fluoride-ethylene copolymer. Further, the suitable polymers and oligomer compound also include compounds prepared by introducing a functional group such as hydroxyl, amino, epoxy or carboxyl into any one of the above organic fluorine compounds, and fluorine polyethers or fluorine-containing poly(meth)acrylates. Typical examples of the polyethers include perfluoroethylene oxide, perfluoropropylene oxide, a perfluoromethylene oxide-perfluoropropylene oxide copolymer, a perfluoromethylene oxide-perfluoroethylene oxide copolymer, a perfluoroethylene oxide-perfluoropropylene oxide copolymer and a compound prepared by introducing carboxyl, hydroxylalkyl, ester or isocyanate into the terminus or molecular chain of any one of the above fluorine-containing polyethers. Typical examples of the (meth)acrylates include polytrifluoroethyl (meth)acrylate, polytetrafluoropropyl (meth)acrylate, polyoctafluoropentyl (meth)acrylate, polyheptadecafluorodecyl (meth)acrylate, a copolymer of fluorine-containing (meth)acrylates, and a copolymer of fluorine-containing (meth)acrylate and other (meth)acrylate such as methyl (meth)acrylate, hydroxyethyl (meth)acrylate or glycidyl (meth)acrylate. These may be used in combination. A hydrophobic coating layer formed of the above silicone compound containing fluorine has remarkably low surface tension and shows excellent water repellency. The hydrophobic/oleophobic agents are applied in known fashion in solution using conventional deposition methods, with or without heating. Other hydrophobic agents which may be used include those disclosed in U.S. Pat. Nos. 6,025,025; 5,523,162; 5,328,768; 4,997,684; and 4,983,459, all of which are hereby incorporated by reference in their entirety. If heated, the temperature ranges from about 50° C. to about 250° C., more preferably from about 80° C. to about 120° C. The duration of heating ranges from about 5 min to about 120 min, more preferably from about 10 min to about 30 min. The hydrophobic coating may further contain waxes, lower alcohols, polishing agents, surfactants, solvents, catalysts, beading agents, preservatives, anti-foaming agents, UV absorber/UV light stabilizer or a freeze-thaw additive etc. as desired. Examples of the usable waxes are vegetable waxes such as carnauba wax, Japan waxes, ouricury wax, esbal wax; animal waxes such as insect waxes, shellac wax, spermacetic wax; petroleum waxes such as paraffin wax, microcrystalline wax, polyethylene wax, ester wax, oxide wax; as well as mineral waxes such as montan wax, ozokerite, celesine, etc. In addition to these waxes, higher aliphatic acid such as palmitic acid, stearic acid, margaric acid, behenic acid; higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, margaryl alcohol, myricyl alcohol, eicosanol, etc.; higher aliphatic acid esters such as cetyl palmitate, myricyl palmitate, cetyl stearate, myricyl stearate, etc.; higher amides such as acetamide, propionamide, palmitic acid amide, stearic acid amide, amide wax, etc. and higher amines such as stearylamine, behenylamine. These can be used singly or as a combination of two or more thereof. Of these, waxes having a melting point of about 50 to about 130° C. when measured using a Yanagimoto MJP-2 melting point tester are most preferred. The waxes should have a particle size of generally about 0.1 to about 10 μm, preferably about 0.5 to about 2.0 μm when dispersed in the composition. For non-visual applications, the content of the waxes should be generally from about 2 to about 20 wt %, preferably about 5 to about 15 wt %. For visual applications, the content of the waxes should be generally from about 0.1 to about 10 wt %, preferably about 0.5 to about 2 wt %. Examples of the above described alcohols are monohydric alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, allyl alcohol, crotyl alcohol, 2-butenol, etc.; dihydric alcohols such as ethylene glycol, propylene glycol, etc.; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, etc. These alcohols can be used singly or as a combination or two or more. The alcohols are used in an amount of usually about 70 to about 99 wt %, preferably about 90 to about 98 wt %. Of the surfactants, any of anionic, cationic, nonionic and amphoteric surfactants can be used and there is no restriction as long as they do not impair the durability or hydrophobicity of the composition. Examples of the usable anionic surfactants are higher aliphatic acid salts such as aliphatic acid salt, rosin acid soap, N-acylcaboxylic acid salts, ethercarboxylic acid salt, etc.; sulfonic acid salts such as alkylsufonic acid salts, sulfosuccinic acid salts, esterified sulfonic acid salt, alkylbenzensulfonic acid salts, alkylallylsulfonic acid salt, alkylnaphthalenesulfonic acid salts, N-acylsulfonic acid salts; sulfuric acid ester salts such as sulfated oil, sulfuric acid ester salts such as alkyl sulfate salts, alkylallylether sulfate salts, aminosulfuric acid salts, etc.; phosphoric acid ester salts such as alkylphosphate salts, etherphosphoric acid salts, alkyletherphosphoric acid salts, alkylallyletherphosphoric acid satas, amidophosphate salts, etc. and formaldehyde-condensed sulfonic acid salts. Of these, preferred are alkanol amines and amine salts alkylbenzensulfonic acid, alkanolamines and amine salts of alkylsulfonic acid, metal salts of alkylphophoric acid and metal salts of higher aliphatic acid. Examples of the usable cationic surfactants are aliphatic amine salts such as primary amine salts, secondary amine salts, tertiary amine salts; quaternary ammonium salts, hidroxyammonium salt, ether ammonium salts and quaterary ammonium salts thereof, etc.; and aromatic quaternary ammonium salts such as benzalconium salt, benzetonium salt, pyridinium salt, imidazolinium salt, etc. Of these, tertiary amine salts such as diethylamide of stearic acid; quaternary ammonium salts such as stearyltolylmethylammonium chloride; and benzalconium salts such as stearyldimethylbenzylammonium chloride, etc. Examples of the amphoteric surfactants, betaines such as carboxybetaines, sulfobetaines, etc., aminocarboxylic acids, imidazoline derivatives. Of these, imidazoline derivatives are preferred. Examples of the usable nonionic surfactants are polyoxyethylene alkylethers, polyoxyethylene alkylphenylethers, polyoxyethylene alkyl esters, sorbitane alkylesters, polyoxyethylene sorbitane ester. etc. Of these, preferred are polyoxyethylenealkylethers, polyoxyethylene-alkylphenylethers and polyoxyethylene alkyl esters. When those having a low HLB value of about 5 to about 10 is used, W/O (water in oil) type emulsions are formed, which have good water-repellency. When those having a high HLB value of not less than about 12 are used, O/W water in oil type emulsions are formed, which have good detergency and wipe-off property although they are rather poor in water repellency. These surfactants can be used singly or as a combination of two or more thereof. The content of these surfactants in the hydrophobic coating is generally no more than about 5.0 wt %, preferably about 0.005 to about 2 wt %. Further, as the above-mentioned polishing agents, diatomaceous earth (kieselguhr), alumina, silica, zirconium oxide, etc. can be used. These polishing agents generally have a particle size of not more than about 10 μm, preferably about 1 to about 5 μm. For non-visual applications, the content of the polishing agent is generally about 1 to about 20 wt %, preferably about 5 to about 10 wt %. For visual applications, the content of the polishing agent is generally about 0.1 to about 10 wt %, preferably about 0.5 to about 2 wt %. Various processes are available for coating the surface of a glass panel with a solution to produce a hydrophobic film thereon. They include a dipping process for immersing a glass panel in a coating solution, a spraying process for spraying a coating solution from a spray gun onto a glass panel, a spin-coating process for dropping a coating solution onto a glass panel while the glass panel is being rotated at high speed, thereby to spread the applied coating solution uniformly over the glass panel under centrifugal forces, and a flow process for flowing a coating solution from a nozzle onto an upper edge of a glass panel. A sponge, a cloth, or a piece of paper impregnated with the hydrophobic coating obtained as described above is used to apply the hydrophobic coating to the surface of glass requiring water repellency. The applied layer of the water repellent is left to dry. When the hydrophobic coating dries, a thin white film is formed on the glass surface. The treatment is completed by wiping this white film with a damp cloth or sponge until the glass becomes transparent. Instead of applying the hydrophobic coating with a sponge or the like, the hydrophobic coating may be applied to the glass surface by spraying and then spread with a sponge or a cloth. The glass to be coated is glass comprising mineral and/or organic glass. It is used, in particular, in the aeronautical, railroad or automobile areas. It also can be used in construction or in interiors, for example, as decorative panels, for furnishings, etc. The substrate on which the coating is capable of being applied moreover may be made up of any material comprising surface hydroxylated groups, such as glass products coated or not coated with mineral and/or inorganic, ceramic, vitroceramic layers (for example, heating plates), vitrified products, concrete or flagstones. The substrate may be glass, silicon, alumina, or any surface having a high oxygen content. High oxygen content is defined as having an oxygen content of from about 40% to about 80%. The coating is applicable in areas as different as those of glazing, electric domestic appliances, building (windows), cooking utensils, sanitary fixtures (washbasin, bathtub), construction materials, etc. The composition also may be deposited on a layer which is at least partially degraded. This degradation may be due, for example, to natural aging or to a mechanical or chemical abrasion. Abrasion may be due to the rubbing of windshield wipers or to the impact of rain, hail, or shock. As the surface on a degraded layer is as effective as the initial surface, it is not necessary to prepare the surface, such as with abrasion, or polishing, prior to deposition of the composition. Nonetheless, the durability of the layer, preferably, may be improved by a preliminary treatment of the substrate with a priming compound of the type SiX4, where X is a hydrolyzable group, for example chloride or alkoxy. X may be other halides, such as bromine. The alkoxy may have about 1 to about 100 carbon atoms. Priming increases the reactivity of the glass, which results in an improvement in attachment of the fluorous silane. In addition, the priming disorganizes the fluorous layer and thus makes it possible to form it with a greater thickness, at least equal to 100 angstroms, without, however, exceeding about 500 angstroms: it does not refer to a monomolecular layer. The increase thus obtained in the amount of fluorine deposited results in an increased durability under conditions of exposure to ultraviolet radiation. Moreover, at the above-mentioned thickness values for the fluorous layer, a scratch in the layer is not visible to the naked eye. The priming treatment may be accomplished by using the same deposition process as that used for the deposition of the hydrophobic and oleophobic layer, and by using the same aqueous solvent and catalyst system. The priming compound may contain from about 0.001 to about 5% by weight of SiX4. The treatment with the priming compound has the effect of increasing the number of reactive sites (hydroxylated sites) on the surface of the substrates. Other primer layers that may be used to increase the durability of the hydrophobic coating may be found in U.S. Pat. Nos. 6,025,025; 6,001,485; 5,328,768; and 5,523,161 which are hereby incorporated by reference in their entirety. When an organic silicone compound or organic fluorine compound having a hydroxyl group in the molecule is used, a curing agent such as polyisocyanate may be added to improve the moisture resistance and water resistance of the film. The curing agent is not always required, and may be selected depending upon use to increase the film stability by promoting the curing of an organic silicone compound and/or organic fluorine compound having a functional group. Further, as a catalyst for promoting the hydrolysis and condensation of the alkoxy group, mainly used are acid catalysts such as hydrochloric acid, sulfuric acid, nitric acid and glacial acetic acid, alkali catalysts such as sodium hydroxide, potassium hydroxide and ammonia, ammonium perchlorate, magnesium perchlorate, and aluminum acetylacetonate. As a catalyst for a reaction between the isocyanate and hydroxyl, generally used are tin-containing catalysts such as dibutyltin dilaurate and amine-containing catalysts. For bonding the mercapto and vinyl, generally used is a platinum catalyst. For the heat polymerization of the (meth)acryloxy, a large number of catalysts including azo- and peroxide-containing catalysts are commercially available, and for the polymerization thereof by ultraviolet light or electron beam, a large number of catalysts including acetophenone- and benzophenone-containing catalysts are commercially available. For the polymerization of the vinyl, there is used a known method using an anionic or cationic catalyst. Alternative pre-treatment means effective for the surface of substrates such as glass, metals, ceramics and plastics, silica (SiO2), is for example deposited or polyhalogenated silane such as dichlorosilane, trichlorosilane and tetrachlorosilane is coated and reacted with water. The pre-treatment can be with or without washing with a non-aqueous solution and increases the formation of silanol (—SiOH) groups on the substrate surface. By so doing, the chemical adsorbing material can be reacted in a high concentration. The durability of the hydrophobic composition is also improved by modifying the surface of the substrate to provide an increased number of bonding sites on the surface of the substrate. These sites react with the hydrophobic coating to more effectively bond it to the substrate, thereby improving the durability of the hydrophobic coating. Exposing the bonding sites is sometimes referred to as activation. In a preferred embodiment of the invention, the bonding sites are exposed by treating the surface of the substrate, prior to applying the hydrophobic coating over the surface of the substrate, with a dispersion including at least one abrading compound and at least one acid in solution. The abrading compound/acid solution dispersion loosens and dislodges materials, such as surface contaminants and other glass constituents, which block the bonding sites, without materially affecting the mechanical or optical properties of the surface of the substrate. A synergistic effect has been observed where the abrading compound is dispersed in the acid solution. More particularly, a hydrophobic coating applied to a substrate surface prepared with the abrading compound/acid solution dispersion generally exhibits improved durability as compared to preparing the substrate surface with an abrading operation alone or an acid washing operation alone, and at least as good or better than an abrading operation followed a separate acid washing operation. It is believed that the high durability is obtained from the abrading compound/acid solution dispersion because the acid solution primarily chemically weakens chemical bonds between the materials blocking the bonding sites and the substrate, rendering such materials more easily removed from the surface of the substrate, while the abrading compound(s) operate with the acid solution to physically loosen and dislodge the materials which block the bonding sites. Additionally, either the acid solution, the abrading compound or both may operate to roughen the surface of the substrate, thereby providing more surface area, and in turn more bonding sites, for reaction with the hydrophobic coating to improve the durability of the hydrophobic coating. Further, use of the abrading compound/acid solution dispersion as disclosed reduces the cost and time to prepare the surface of the substrate over a two-step operation of abrading followed by acid activation. Other surface preparation methods include those disclosed in U.S. Pat. No. 5,980,990 which is hereby incorporated by reference in its entirety. In some embodiments, a method of making a hydrophobic surface comprises applying a water repellant composition to the surface of a substrate, wherein the water repellant composition comprises a curing agent and a silsesquioxane silicone resin. In some embodiments, the water repellant composition further comprises a solvent. The contact angles recited herein are measured by an instrument manufactured by AST and is video based. A high magnification camera captures an image of the drop on the surface and software then calculates the resulting contact angle using the profile the drop makes with the surface. Table 1 in the following indicates various compositions of hydrophobic coatings in accordance with embodiments of the invention. TABLE 1 Preferred More Preferred Most Preferred Component Range (wt. %) Range (wt. %) Range (wt. %) Silicone Resin 0.1 to 5 0.25 to 2.0 0.75 to 1.25 Solvent 74.9 to 99.78 89.9 to 99.45 95 to 99 Catalyst 0 to 0.1 0 to 0.1 0.01 to 0.05 Curing Agent 0.025 to 10 0.05 to 4 0.1 to 2 Additives 0.1 to 10 0.25 to 4 0.5 to 2 The following examples are presented to illustrate various embodiments of the invention. All numerical values are approximate numbers. The specific details in each example should not be construed to limit the invention as otherwise described and claimed herein. The following tables show various hydrophobic compositions made in accordance with embodiments of the invention. The amount of each component added to each tinting composition is provided in weight percent of the total composition. Formulations were prepared and applied to a standard 4″×4″ plate glass. The formulations, in grams, are listed in Table 2. Additional formulations included: Composition A—Octadecyltrimethoxysilane (ODS) (1%) in cyclohexane available from Gelest, Inc.; and Composition B—Rain-X, a commercial hydrophobic glass treatment available from Pennzoil-Quaker State, Houston, Tex. The resin is an MQ silicone resin, such as those available from Wacker-Chemie, Munich, Germany. The reactive amino silicone may be grade F756 available from Wacker-Chemie. The isooctane is available from Aldrich Chemical. The tri-ethoxysilane is available from Gelest, Inc. The zirconium (IV) propoxide is available from Aldrich Chemical. The tetra-ethylorthosilicate is available from Aldrich Chemical. The 3-aminopropyltrimethoxysilane is available from Aldrich Chemical. The poly(methylsilsesquioxane) is available from Gelest, Inc. The silicone wax may be grade W23 brand available from Wacker-Chemie. The cyclohexane is available from Aldrich Chemical. The ODS topcoat is approximately 1-5 nm thick, using from about 1 to about 10 mL of solution to achieve this. The formulations were applied to the glass substrate and subjected to a standard Taber Abraser with CS-0 wheels. The wheels were dressed using 220 grit sandpaper to make them slightly more abrasive. The wheels are wiped down with isopropanol prior to running a sample to remove any excess debris. Contact angles are measured using the ASTM D-5275-99 method and an apparatus available from AST such as the VCA Optima with a drop size of approximately 0.5 μL. The general method is placing a drop of water on the surface and taking a snapshot of the picture from the computer screen. The software then calculates the contact angle in the snapshot. Measurements are taken every 200 cycles to evaluate the coating performance and are shown in Table 3. TABLE 2 Reactive Zirconium Tetra- 3-Amino Poly ODS amino Triethoxy- (IV) Ethylortho- Propyltrimethoxy- (methyl- Silicone Top Composition Resin silicone Isooctane silane Propoxide silicate silane silsesquioxane) wax Cyclohexane coat C 0.1 0.05 5 0.05 D 0.1 0.05 5 0.025 0.025 0.025 E 0.1 0.05 5 0.025 .025 F 0.1 0.05 5 0.05 G 0.1 0.1 0.1 9.7 H 0.1 0.05 5 0.025 0.025 0.025 yes I 0.1 0.05 5 0.05 yes J 0.1 0.05 5 0.05 yes K 0.1 0.05 5 0.025 0.025 0.025 0.01 yes L 0.1 0.05 5 0.05 0.01 yes M 0.1 0.05 5 0.05 0.01 yes TABLE 3 Contact time A B C C (oven) D E F (oven) G G + C G + D H I J K L M 0 101.325 105.1 112.75 126.7 123.7 123.7 113.55 104.85 106.5 92.45 104.2 103 105.7 101.6 99.3 104.1 200 91.85 101.3 84.45 58.75 67.8 81.95 58.65 87.15 93.65 84.6 95.5 95.4 96.8 67.9 93.4 92.8 400 82.85 71.1 72.65 72.75 63.7 70.85 73.3 94.3 97.2 97.2 69.9 65.5 600 62.65 63.35 66.3 64.45 67.4 63 85 87 84.4 800 64.8 68 62.2 The addition of silicone resin improves the durability of the hydrophobic coating. The resin increases the contact angle of the solution and also maintains a high contact angle for longer periods of time. While the invention has been described with respect to a limited number of embodiments, the specific features of one embodiment should not be attributed to other embodiments of the invention. No single embodiment is representative of all aspects of the inventions. In some embodiments, the compositions may include numerous compounds and/or characteristics not mentioned herein. In other embodiments, the compositions do not include, or are substantially free of, one or more compounds and/or characteristics not enumerated herein. Variations and modifications from the described embodiments exist. For example, the hydrophobic coating need not be a mixture within the compositions given above. It can comprise any amount of components, so long as the properties desired in the hydrophobic coating are met. It should be noted that the application of the hydrophobic coating is not limited to coatings for automobiles; it can be used in any environment which requires a durable hydrophobic coating, such as a airplanes, trucks, vans or buses. It is noted that the methods for making and using the hydrophobic coating composition are described with reference to a number of steps. These steps can be practiced in any sequence. One or more steps may be omitted or combined but still achieve substantially the same results. The appended claims intend to cover all such variations and modifications as falling within the scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Hydrophobic coatings for glass surfaces are known using traditional silane chemistry. When a glass surface is provided with a hydrophobic coating and the glass is used for a windshield or side window of an automobile, the driver's visual field is secured. Typically, an alkoxylated silane is allowed to react with the glass surface, thereby attaching the coating material to the substrate. Unfortunately, the inherent disadvantage to this approach is that the resulting silicone bond (Si—O—Si) is vulnerable to hydrolysis. Methods to minimize the hydrolysis include increasing the packing density of the material on the surface. This causes steric effects to aid in the prevention of water reaching the reaction site, thereby preventing hydrolysis. These hydrophobic coatings provide improved visibility when used on automobile window glass. However, these coatings have a tendency to wear off within a few months. The problems of hydrophobic coatings also extend to the airline industry. The current coating technologies are inadequate because of their limited durability. Technologies for improving the visibility in aircraft under rainy conditions include “jet blast” and windshield wipers. Windshield wiper systems further include hydrophobic coatings for greater effectiveness. The “jet blast” system involves blanketing the surface of the windshield with a blanket of high velocity air. However, there is still a need for a more durable coating that will last for more than a year and significantly improve the pilot's visual field during inclement weather. The above water-repellent glass is generally produced by a wet-coating method in which a water-repellent agent containing an organic silicon compound, typified by a polydimethylsiloxane compound or a fluorine-containing silicon compound, is wet-coated on a glass surface, or by a dry-coating method in which the above water-repellent agent is dry-coated by means of plasma or vapor deposition. However, in the above methods of coating the water-repellent agent directly on a glass surface, it is difficult to maintain water repellency for a long time, since the adhesion strength between the water-repellent agent and the glass is low. The non-wettability of a substrate, more commonly referred to as its hydrophobic/oleophobic property, consists in the fact that the contact angles between a liquid and this substrate are high, for example at least about 60° for water. The liquid therefore tends to flow readily over the substrate, in the form of drops, simply under gravity if the substrate slopes, or under the effect of aerodynamic forces in the case of a moving vehicle. Examples of agents which are known to impart this hydrophobic/oleophobic property are fluorinated alkylsilanes as described in U.S. Pat. Nos. 5,571,622; 5,324,566; and 5,571,622 which are hereby incorporated by reference in their entirety. According to these patents, this layer is obtained by a solution containing fluorinated organosilanes in a non-aqueous organic solvent is applied to the surface of a substrate. Preferred non-aqueous organic solvents include n-hexadecane, toluene, xylene, etc. These solvents are particularly suitable for a fluorinated chlorosilane. It is also possible to use a methyl or ethyl alcohol as solvent when the fluorinated silane is a fluorinated alkoxysilane. The hydrophobic coating includes hydrolyzable fluorinated alkylsilanes. They are preferably of the monomolecular type obtained from at least one fluorinated alkylsilane whose carbon chain, which may be branched, comprises at least six carbon atoms, with the carbon of the extremity (extremities) being entirely substituted by fluorine. The layer can also be obtained from fluorinated alkylsilanes or from a mixture of fluorinated alkylsilanes and, possibly, a mixture of fluorinated alkylsilanes and silanes of the SiX 4 type in which X is a hydrolyzable group. The current hydrophobic coatings also have environmental and safety issues. The coating may involve the application of perfluoro alkyl silanes in a halogenated hydrocarbon solvent. Current coatings also employ cationic quaternary ammonium compounds and silico-titanium copolymers. For the foregoing reasons, there is a need for a more durable hydrophobic coating, preferably with a contact angle of at least about 90°, more preferably 100° capable of maintaining acceptable contact angles for at least about 1.5 years. This minimum is extended to about 3 years if the coating is not easily replaceable. | <SOH> SUMMARY OF THE INVENTION <EOH>Embodiments of the invention fulfill the aforementioned need in one or more of the following aspects. In one aspect, the invention relates to a durable water repellent composition for surfaces which comprises a curing agent and a silicone resin. The silicone resin is preferably a silsesquioxane silicone resin. In some embodiments, the curing agent is a C 16 -C 18 alkoxysilane and the silicone resin is an MQ resin. In other aspects of the invention, the invention relates to an article comprising a glass substrate of which at least a portion of the substrate is treated with the durable water repellent composition discussed above. In some embodiments, the curing agent and the silicone resin is at least in part crosslinked. In some embodiments, the article may further include a primer layer, a topcoat layer, or both. Additional aspects of the invention and characteristics and properties of various embodiments of the invention become apparent with the following description. | 20040707 | 20080318 | 20050113 | 57669.0 | 0 | FIGUEROA, JOHN J | DURABLE HYDROPHOBIC SURFACE COATINGS USING SILICONE RESINS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,886,018 | ACCEPTED | Wire winding tool article and method | In an article and method for enabling a wire winding tool to wind a loop of wire about a workpiece and secure the wire loop to the workpiece, the wire winding tool includes a body element which includes a tapered wire-holding end and a hollow cylindrical shaft with interior threads and side slots. The tool further includes a threaded shaft including a distal end and transverse pins which extend therefrom through the body element side slots and are moveable therein, and about which free ends of the wire are wound. Also, the tool includes a nut threadably connected to the threaded shaft, which is threadably moveable to enable the threaded shaft to retract and pull the wire free ends so as to wind and secure the wire to the workpiece. | 1. An article for enabling a wire to be wound about a workpiece, comprising a wire winding tool, wherein the wire includes opposed free ends, and is adapted to form a loop, and is further adapted to form a winding, adapted to extend about the workpiece and through the loop and to be wound about the workpiece, wherein the wire winding tool comprises: a body element, which includes a distal end which is generally tapered-shaped to form a tapered end, adapted to hold the wire loop in position during winding of the wire, and a cylindrical shaft, which is hollow, and includes interior threads and side slots, and from which the tapered end extends; a threaded shaft, adapted to extend in and threadably engage the interior threads of the hollow portion of the cylindrical shaft, and to be threadably movable relative to the body element, which threaded shaft includes a distal end, and transverse pins extending therefrom through the side slots in the body element, adapted to be moveable in the body element side slots and to enable the wire free ends to be secured thereto; and a nut, adapted to be threadably connected to the threaded shaft, and, upon threaded movement of the nut, to enable the threaded shaft to retract relative to the body element such that the transverse pins pull on the wire free ends secured thereto so as to wind the wire about the workpiece and enable the wire winding to be secured to the workpiece. 2. The article of claim 1, wherein the side slots of the body element are elongated. 3. The article of claim 1, wherein the cylindrical shaft of the body element further includes a proximal end, which includes flat side surfaces for enabling securing of a gripping member thereto. 4. The article of claim 1, wherein the threaded shaft further includes a proximal end which is non-threaded, adapted to enable extension a loop therethrough. 5. The article of claim 1, wherein the nut includes side wing-shaped projections for enabling gripping thereof. 6. The article of claim 1, further including a washer positionable between the nut and the body element. 7. The article of claim 1, wherein the article is comprised of stainless steel. 8. The article of claim 2, wherein the threaded shaft is elongated to enable elongated movement of the transverse pins in the elongated side slots. 9. The article of claim 4, wherein the non-threaded proximal end of the threaded shaft has a hole therethrough for enabling extending a loop therethrough. 10. An article for enabling a wire to be wound about a workpiece, comprising a wire winding tool, wherein the wire includes opposed free ends, and is adapted to form a loop, and is further adapted to form a winding, adapted to extend about the workpiece and through the loop and to be wound about the workpiece, wherein the wire winding tool comprises: body means, which include a distal end which is generally tapered-shaped to form a tapered end, adapted to hold the wire loop in position during winding of the wire, and a cylindrical shaft, which is hollow, and includes interior threads and side slots, and from which the tapered end extends; a threaded shaft, adapted to extend in and threadably engage the interior threads of the hollow portion of the cylindrical shaft, and to be threadably movable relative to the body means, which threaded shaft includes a distal end, and transverse pins extending therefrom through the side slots in the body means, adapted to be moveable in the body means side slots and to enable the wire free ends to be secured thereto; and a nut, adapted to be threadably connected to the threaded shaft, and, upon threaded movement of the nut, to enable the threaded shaft to retract relative to the body means such that the transverse pins pull on the wire free ends secured thereto so as to wind the wire about the workpiece and enable the wire winding to be secured to the workpiece. 11. A method of enabling a wire to be wound about a workpiece, wherein the wire includes opposed free ends, and is adapted to form a loop, and is further adapted to form a winding, adapted to extend about the workpiece and through the loop and to be wound about the workpiece, in an article which comprises a wire winding tool, comprising a body element, which includes a distal end which is generally tapered-shaped to form a tapered end, adapted to hold the wire loop in position during winding of the wire, and a cylindrical shaft, which is hollow, and includes interior threads and side slots, and from which the tapered end extends, a threaded shaft, adapted to extend in and threadably engage the interior threads of the hollow portion of the cylindrical shaft, and to be threadably movable relative to the body element, which threaded shaft includes a distal end, and transverse pins extending therefrom through the side slots in the body element, adapted to be moveable in the body element side slots and to enable the wire free ends to be secured thereto, and a nut, adapted to be threadably connected to the threaded shaft, and, upon threaded movement of the nut, to enable the threaded shaft to retract relative to the body element such that the transverse pins pull on the wire free ends secured thereto so as to wind the wire about the workpiece and enable the wire winding to be secured to the workpiece, wherein the method comprises: forming a loop and a winding adapted to extend about the workpiece and through the loop and to be wound about the workpiece, by the wire; holding the wire loop in position during winding of the wire, by the body element tapered end; threadably moving the threaded shaft along the interior threads of the cylindrical shaft hollow portion; moving the threaded shaft transverse pins with the wire free ends secured thereto along the body element side slots; and threadably moving the nut along the threaded shaft and retracting the threaded shaft relative to the body element, so as to pull the transverse pins with the wire free ends secured thereto, wind the wire about the workpiece, and secure the wire winding to the workpiece. 12. The method of claim I 1, wherein the side slots of the body element are elongated, and wherein moving the threaded shaft transverse pins further includes moving along the elongated body element side slots. 13. The method of claim 1 1, wherein the cylindrical shaft of the body element further includes a proximal end, which includes flat side surfaces for enabling securing of a gripping member thereto, further comprising enabling securing of a gripping member to the flat side surfaces of the proximal end of the body element cylindrical shaft. 14. The method of claim 11, wherein the threaded shaft further includes a proximal end which is non-threaded, adapted to enable extension of a loop therethrough, further comprising enabling extension of a loop through the non-threaded proximal end of the threaded shaft. 15. The method of claim 11, wherein the nut includes side wing-shaped projections for enabling gripping thereof, and wherein threadably moving the nut further includes enabling gripping of the side wing-shaped projections of the nut. 16. The method of claim 11, further including a washer positionable between the nut and the body element, and wherein threadably moving the nut further includes enabling moving of the washer. 17. The method of claim 11, wherein the article is comprised of stainless steel, and wherein forming, holding, threadably moving the threaded shaft, moving the threaded shaft transverse pins, and threadably moving the nut are enabled relative the stainless steel article. 18. The method of claim 12, wherein the threaded shaft is elongated to enable elongated travel of the transverse pins in the elongated side slots, and wherein moving the threaded shaft transverse pins includes elongated travel of the transverse pins in the elongated side slots of the threaded shaft. 19. The method of claim 14, wherein the non-threaded proximal end of the threaded shaft has a hole therethrough for enabling extension of a loop therethrough, and wherein enabling extension of the loop includes enabling extension of the loop through the hole in the non-threaded proximal end of the threaded shaft. 20. A method of enabling a wire to be wound about a workpiece, wherein the wire includes opposed free ends, and is adapted to form a loop, and is further adapted to form a winding, adapted to extend about the workpiece and through the loop and to be wound about the workpiece, in an article which comprises a wire winding tool, comprising body means, which include a distal end which is generally tapered-shaped to form a tapered end, adapted to hold the wire loop in position during winding of the wire, and a cylindrical shaft, which is hollow, and includes interior threads and side slots, and from which the tapered end extends, a threaded shaft, adapted to extend in and threadably engage the interior threads of the hollow portion of the cylindrical shaft, and to be threadably movable relative to the body means, which threaded shaft includes a distal end, and transverse pins extending therefrom through the side slots in the body means, adapted to be moveable in the body means side slots and to enable the wire free ends to be secured thereto, and a nut, adapted to be threadably connected to the threaded shaft, and, upon threaded movement of the nut, to enable the threaded shaft to retract relative to the body means such that the transverse pins pull on the wire free ends secured thereto so as to wind the wire about the workpiece and enable the wire winding to be secured to the workpiece, wherein the method comprises: forming a loop, and a winding adapted to extend about the workpiece and through the loop and to be wound about the workpiece, by the wire; holding the wire loop in position during winding of the wire, by the body means tapered end; threadably moving the threaded shaft along the interior threads of the cylindrical shaft hollow portion; moving the threaded shaft transverse pins with the wire free ends secured thereto along the body means side slots; and threadably moving the nut along the threaded shaft and retracting the threaded shaft relative to the body means, pulling the transverse pins with the wire free ends secured thereto, winding the wire about the workpiece and securing the wire winding to the workpiece. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to hand tools, and, more particularly, to a new and improved hand tool for enabling a wire clamp to be tightly wound about a workpiece. 2. General Background and State of the Art It has been known to wrap a clamp about a workpiece such as a rubber hose which in turn may extend about a pipe, and to enable the clamp to be tightened about the hose and pipe to tightly bind the hose to the pipe. The clamp may include a screw which may be threadably advanced so as to tighten the clamp. It has also been known to wrap a loop of wire about the workpiece to form a wire loop clamp, and to use a hand tool to apply pressure to and tighten the wire loop. The loop of wire may include a plurality of windings of the wire about the workpiece. However, it would be desirable to provide a hand tool which would enable effective, convenient and efficient tightening of a wire loop clamp about a workpiece. Moreover, the tool may hang up on the wire loop upon movement of the tool thereabout in forming the wire loop clamp, interfering therewith. Furthermore, it may be difficult to get a good grip on the tool in instances where such may be required to enable effective moving of the tool for forming and securing the wire loop clamp. In addition, it would be desirable to enable convenient carrying of the tool. In view of these considerations, effective winding and securing of a wire loop clamp about a workpiece may be implemented in a wire winding tool which enables efficient tightening of a wire loop clamp, effective operation of the tool without hanging up on the wire loop, and convenient carrying of the tool. Therefore, there has existed a need for an article and method for enabling a wire clamp to be wound about a workpiece in an effective and efficient manner, while preventing interference with the wire loop clamp and enabling convenient access thereto. Accordingly, the present invention fulfills these needs by providing an efficient and effective wire loop clamp winding tool with enhanced gripping and carrying thereof. INVENTION SUMMARY Briefly, and in general terms, the present invention provides an article for enabling a wire clamp to be wound about a workpiece, comprising a wire winding tool, wherein the wire includes opposed free ends, and is able to form a loop, and is further able to form a winding which is extendable about the workpiece and through the loop, and to be wound about and secured to the workpiece. More particularly, the present invention includes a body element, which includes a distal end which is generally tapered-shaped to form a tapered end, able to hold the wire loop in position during winding of the wire, and a cylindrical shaft, which is hollow, and includes interior threads and side slots, and from which the tapered end extends. The article, in accordance with the present invention, also includes a threaded shaft, extendable in and threadably engageable with the interior threads of the hollow portion of the cylindrical shaft, and threadably movable relative to the body element, which threaded shaft includes a distal end, and transverse pins extending therefrom through the side slots in the body element, moveable in the body element side slots and able to enable the wire free ends to be secured thereto. The article of the present invention further includes a nut, threadably connected to the threaded shaft, and, upon threaded movement of the nut, able to enable the threaded shaft to retract relative to the body element such that the transverse pins pull on the wire free ends secured thereto so as to wind the wire about the workpiece and enable the wire winding to be secured to the workpiece. Therefore, one aspect of the present invention is that it provides a wire winding tool for effectively forming and securely winding a wire loop clamp about a workpiece. Another aspect of the present invention is that it includes a unitary cylindrical shaft for preventing the tool from hanging up on the wire loop clamp during movement thereof. A further aspect of the present invention is that it includes gripping-enabling surfaces and threadable movement-enabling members to enable effective gripping and tightening movement of the tool. Still another aspect of the invention is that it enables the tool to be connected to a loop for convenient carrying thereof. These and other aspects and features of the invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings of illustrative embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational partly-fragmentary view of a wire winding tool and a wire wound about a workpiece in accordance with the present invention. FIG. 2 is a side elevational partly-sectional view of a wire winding tool and a wire wound about a workpiece in accordance with the present invention. FIG. 3 is a fragmentary view of the distal end of a winding wire tool in accordance with the present invention. FIG. 4 is a fragmentary view of a wire loop wound about and secured to a workpiece in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is directed to an improved article and method for providing a wire winding tool, which is able to wind a formed loop clamp securely about a workpiece in an effective and efficient manner. Referring to the drawings, wherein like numerals denote like or corresponding parts, and in particular to FIGS. 1-4, there is shown an article 10 for enabling a wire 12 to be wound about a workpiece 14, comprising a wire winding tool, wherein the wire 12 includes opposed free ends 16, and is able to form a loop 18, and is further able to form a winding 20, extendable about the workpiece 14 and through the loop 18 and able to be wound about and secured to the workpiece 14. The tool 10 may be utilized for emergency repairs or permanent fixes. It is lightweight, substantially lighter than worm gear and tension clamps. The wire 12 for example may be comprised of stainless steel, safety wire, welding, electric fence, or bailing wire. The workpiece 14 about which the wire 12 is to be wound and secured may for example comprise high pressure hose, hydraulic hose, power steering hose, broken poles, pieces of a broken tool handle, fences and gates, farm machinery, fishing poles, mufflers and tail pipes, furniture and flower pots, toys and sporting equipment, cooking pots and pans, leaky hoses, or irrigation and sprinkler systems. In the present invention, the wire winding tool 10 includes a body element 22, which includes a distal end 24 which is generally tapered-shaped to form a tapered end 26, able to hold the wire loop 18 in position during winding of the wire 12, and guide pins 28, for guiding the wire 12 thereover. The body element 22 further includes a cylindrical shaft 30, which is hollow, and includes interior threads 32 and side slots 34, and from which the tapered end 26 extends. The side slots 34 of the body element 22 are elongated. The cylindrical shaft 30 of the body element 22 further includes a proximal end 36, which includes flat side surfaces 38 for enabling securing of a gripping member thereto. The cylindrical shaft 30 may for example be comprised of a single unitary piece of machined stainless steel, with a gradual taper to the tapered end 26, to provide a smoother transition such that hangup of the tool 10 with the wire 12 is prevented while pivoting the tool 10. The flat side surfaces 38 enable enhanced stability in gripping and moving the tool 10. As shown in FIGS. 1-2, the wire winding tool 10 further includes a threaded shaft 40, able to extend in and threadably engage the interior threads 32 of the hollow cylindrical shaft 30, and to be threadably movable relative to the body element 22. The threaded shaft 40 includes a distal end 42, and transverse pins 44 extending therefrom through the side slots 34 in the body element 22, able to be moveable in the body element side slots 34 and to enable the wire free ends 16 to be secured thereto. The threaded shaft 40 further includes a proximal end 46 which is non-threaded. The threaded shaft 40 is elongated to enable elongated movement of the transverse pins 44 in the elongated side slots 34. The non-threaded proximal end 46 of the threaded shaft 40 has a hole 48 therethrough for enabling extending a loop 50 therethrough. The loop which is extendable through the hole 46 may comprise a key ring, for enabling connection of the tool 10 thereto. In accordance with the invention, the wire winding tool 10 also includes a nut 52, able to be threadably connected to the threaded shaft 40, and, upon threaded movement of the nut 52, to enable the threaded shaft 40 to retract relative to the body element 22, such that the transverse pins 44 pull on the wire free ends 16 secured thereto, so as to wind the wire 12 about the workpiece 14 and enable the wire winding 20 to be secured to the workpiece 14. The nut 52 includes side wing-shaped projections 54 for enabling gripping and leveraging for movement thereof. Also, the tool 10 includes a washer 56 positionable between the nut 50 and the body element 22. The washer 56 may be comprised of nylon. As illustrated in FIGS. 1-4, in a method for use of the wire winding tool 10, the operation of the tool 10 is enabled by forming a loop, 18 and forming a winding 20 adapted to extend about the workpiece 14 and through the loop 18 and to be wound about the workpiece 14, by the wire 12. The operation is further enabled by holding the wire loop 18 in position during the winding of the wire 12, by the body element tapered end 26, and by threadably moving the threaded shaft 40 along the interior threads 32 of the cylindrical shaft hollow portion. As seen in FIGS. 1-2, the operation of the wire winding tool 10 is further enabled by moving the threaded shaft transverse pins 44 with the wire free ends 16 secured thereto along the body element side slots 34. Moving the threaded shaft transverse pins 44 further includes moving along the elongated body element side slots 34. Moving the threaded shaft transverse pins 44 includes elongated travel of the transverse pins 44 in the elongated side slots 34 of the threaded shaft 40. In the present invention, the operation of the tool 10 further includes threadably moving the nut 52 along the threaded shaft 40 and retracting the threaded shaft 40 relative to the body element 22, so as to pull the transverse pins 44 with the wire free ends 16 secured thereto, wind the wire 12 about the workpiece 14, and secure the wire winding 20 to the workpiece 14. Threadably moving the nut 52 further includes enabling gripping of the side wing-shaped projections 54 of the nut 52. Threadably moving the nut 52 further includes enabling moving of the washer 56. As depicted in FIG. 4, upon pulling the wire 12 tightly about the workpiece 14, the tool 10 is pivoted upwardly at the distal end 24 thereof to bend the wire 12 over the loop 18. The wire 12 is then cut off to form ends 58 which may then be pinched down over the loop 18 for securing the loop 18 to the workpiece 14. In accordance with the invention, operation of the tool 10 also includes enabling securing of a gripping member to the flat side surfaces 38 of the proximal end 36 of the body element cylindrical shaft 30, and enabling extension of a loop 50 through the non-threaded proximal end 46 of the threaded shaft 40. Enabling extension of the loop 50 includes enabling extension thereof through the hole 48 in the non-threaded proximal end 46 of the threaded shaft 40. Forming, holding, threadably moving the threaded shaft 40, moving the threaded shaft transverse pins 44, and threadably moving the nut 52 may be enabled relative a stainless steel tool 10. In accordance with the present invention, the system and method provide for a wire winding tool which enables the effective forming and securing of a wire loop clamp about a workpiece, which enables efficient gripping and carrying thereof. It will be apparent from the foregoing that, while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited, except by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to hand tools, and, more particularly, to a new and improved hand tool for enabling a wire clamp to be tightly wound about a workpiece. 2. General Background and State of the Art It has been known to wrap a clamp about a workpiece such as a rubber hose which in turn may extend about a pipe, and to enable the clamp to be tightened about the hose and pipe to tightly bind the hose to the pipe. The clamp may include a screw which may be threadably advanced so as to tighten the clamp. It has also been known to wrap a loop of wire about the workpiece to form a wire loop clamp, and to use a hand tool to apply pressure to and tighten the wire loop. The loop of wire may include a plurality of windings of the wire about the workpiece. However, it would be desirable to provide a hand tool which would enable effective, convenient and efficient tightening of a wire loop clamp about a workpiece. Moreover, the tool may hang up on the wire loop upon movement of the tool thereabout in forming the wire loop clamp, interfering therewith. Furthermore, it may be difficult to get a good grip on the tool in instances where such may be required to enable effective moving of the tool for forming and securing the wire loop clamp. In addition, it would be desirable to enable convenient carrying of the tool. In view of these considerations, effective winding and securing of a wire loop clamp about a workpiece may be implemented in a wire winding tool which enables efficient tightening of a wire loop clamp, effective operation of the tool without hanging up on the wire loop, and convenient carrying of the tool. Therefore, there has existed a need for an article and method for enabling a wire clamp to be wound about a workpiece in an effective and efficient manner, while preventing interference with the wire loop clamp and enabling convenient access thereto. Accordingly, the present invention fulfills these needs by providing an efficient and effective wire loop clamp winding tool with enhanced gripping and carrying thereof. | <SOH> INVENTION SUMMARY <EOH>Briefly, and in general terms, the present invention provides an article for enabling a wire clamp to be wound about a workpiece, comprising a wire winding tool, wherein the wire includes opposed free ends, and is able to form a loop, and is further able to form a winding which is extendable about the workpiece and through the loop, and to be wound about and secured to the workpiece. More particularly, the present invention includes a body element, which includes a distal end which is generally tapered-shaped to form a tapered end, able to hold the wire loop in position during winding of the wire, and a cylindrical shaft, which is hollow, and includes interior threads and side slots, and from which the tapered end extends. The article, in accordance with the present invention, also includes a threaded shaft, extendable in and threadably engageable with the interior threads of the hollow portion of the cylindrical shaft, and threadably movable relative to the body element, which threaded shaft includes a distal end, and transverse pins extending therefrom through the side slots in the body element, moveable in the body element side slots and able to enable the wire free ends to be secured thereto. The article of the present invention further includes a nut, threadably connected to the threaded shaft, and, upon threaded movement of the nut, able to enable the threaded shaft to retract relative to the body element such that the transverse pins pull on the wire free ends secured thereto so as to wind the wire about the workpiece and enable the wire winding to be secured to the workpiece. Therefore, one aspect of the present invention is that it provides a wire winding tool for effectively forming and securely winding a wire loop clamp about a workpiece. Another aspect of the present invention is that it includes a unitary cylindrical shaft for preventing the tool from hanging up on the wire loop clamp during movement thereof. A further aspect of the present invention is that it includes gripping-enabling surfaces and threadable movement-enabling members to enable effective gripping and tightening movement of the tool. Still another aspect of the invention is that it enables the tool to be connected to a loop for convenient carrying thereof. These and other aspects and features of the invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings of illustrative embodiments. | 20040706 | 20060502 | 20060112 | 67205.0 | B25B2710 | 0 | THOMAS, DAVID B | WIRE WINDING TOOL ARTICLE AND METHOD | SMALL | 0 | ACCEPTED | B25B | 2,004 |
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10,886,051 | ACCEPTED | Lithographic projection apparatus and a device manufacturing method using such lithographic projection apparatus | A manufacturing method is utilized in lithographic projection apparatus in order to enable all aberrations to be compensated for but with those aberrations that are of most significance to the particular application (the particular pattern, illumination mode, etc.) being given precedence over aberrations that are of lesser significance in relation to that particular application. The method uses a substrate having a target portion for receiving an image, a mask for applying a pattern in accordance with a required patterning application, and a projection system to project a selected beam of radiation onto the mask to produce a specific required patterned beam providing an image of the pattern on the target portion. In order to compensate for the aberrations in a manner that gives precedence to those aberrations of particular significance to the required application, the method incorporates the steps of predicting projection system aberration changes with time, determining the application-specific effect on certain parameters of the image of such predicted projection system aberration changes with respect to certain measured aberration values, generating a control signal specific to the required patterned beam according to such predicted projection system aberration changes in the projection system aberrations with time and their application-specific effect on certain parameters of the image; and carrying out imaging adjustments in dependence on the control signal to compensate for the application-specific effect of the predicted changes in the aberrations on the image. The adjustments are therefore determined optimally for the given application. | 1. Lithographic projection apparatus comprising: a support structure for supporting a patterning device to impart a selected pattern to a beam of radiation; a substrate table for holding a substrate; a projection system for projecting the patterned beam onto a target portion of the substrate to form an image; a predictive system for predicting changes in projection system aberrations with time with respect to measured aberration values; a modelling system for determining an application-specific effect of said predicted projection system aberration changes on at least one parameter of the image for the selected pattern; a control system for generating a control signal specific to the selected pattern according to said predicted projection system aberration changes and their application-specific effect on the at least one parameter of the image; and an image adjusting system, responsive to the control signal, to compensate for the application-specific effect of said predicted projection system aberration changes on the image. 2. Lithographic projection apparatus according to claim 1, wherein the control signal preferentially compensates predicted changes in features of the image in one of two directions in the plane of the image in accordance with known sensitivities of the selected pattern to projection system aberrations in the two directions. 3. Lithographic projection apparatus according to claim 1, wherein the control system is arranged to generate a control signal which preferentially compensates predicted changes in features of the image in a direction normal to a plane of the image, in accordance with known sensitivities of the selected pattern to projection system aberrations in said direction. 4. Lithographic projection apparatus according to claim 1, wherein the control signal further depends on a defined merit function determining relative weightings to be given to the effects of projection system aberrations on the at least one parameter of the image. 5. Lithographic projection apparatus according to claim 1, wherein the predicted changes are predicted on the basis of a lens heating model that predicts changes in at least one aberration value with time as a result of lens heating or cooling. 6. Lithographic projection apparatus according to claim 1, wherein the modelling system is arranged to determine the application-specific effect of said projection system aberration changes on the basis of data indicative of the selected pattern and an illumination mode setting of the projection system. 7. Lithographic projection apparatus according to claim 1, wherein the control signal depends on known correspondence between changes in imaging adjustments of the adjustment system and the aberration changes. 8. Lithographic projection apparatus according to claim 1, further including an overlay metrology feedback system constructed and arranged to correct for a shift in a metrology overlay target for a current layer measured with respect to a metrology overlay target for a previous layer, said shift resulting from said predicted projection system aberration changes and the image adjusting system, on the basis of an optimization procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. 9. Lithographic projection apparatus according to claim 1, further including an alignment system constructed and arranged to compensate for effects of a shift in a respective wafer alignment mark provided for the alignment of each layer of successive layers of images to be applied to the target portion, said shift resulting from said predicted projection system aberration changes and said image adjusting system, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. 10. Lithographic projection apparatus according to claim 1, including an alignment system constructed and arranged to compensate for effects of a shift in a respective mask alignment mark provided for the alignment of each layer of successive layers of images to be applied to the target portion, said shift resulting from said predicted projection system aberration changes and said image adjusting system, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. 11. Lithographic projection apparatus according to claim 1, wherein the control system incorporates a measuring system constructed and arranged to re-measure at least one aberration value when the modelled effect on the at least one image parameter with time is greater than a corresponding threshold value. 12. Lithographic projection apparatus according to claim 1, wherein the image adjusting system is further arranged to carry out imaging adjustments over successive scan positions during scanning exposure of the substrate to allow for variations in the scanned image over the extent of the substrate in order to optimise the image as a function of scan position. 13. A device manufacturing method using lithographic projection apparatus, the method comprising: selecting a patterning device in accordance with a required patterning application, illuminating the patterning device with a beam of radiation to produce a patterned beam; projecting the patterned beam onto the target portion to form an image thereon; predicting changes in projection aberrations with time with respect to measured aberration values; determining an application-specific effect of said predicted projection aberration changes on at least one parameter of the image; generating a control signal specific to the required patterning application according to said predicted projection system aberration changes and their application-specific effect; and adjusting the imaging based on the control signal. 14. The device manufacturing method according to claim 13, wherein the generating further comprises preferentially compensating predicted changes in features of the image in one of two directions in the plane of the image, in accordance with known sensitivities of the selected patterning device to projection system aberrations in the two directions. 15. The device manufacturing method according to claim 13, wherein the generating further comprises preferentially compensating changes in features of the image in a direction normal to the plane of the image, in accordance with known sensitivities of the selected patterning device to projection system aberrations in said direction. 16. The device manufacturing method according to claim 13, wherein the control signal further takes into account a defined merit function determining relative weightings to be given to selected effects of projection system aberrations on different parameters of the image. 17. The device manufacturing method according to claim 13, wherein said predicting is performed on the basis of a lens heating model that predicts changes in at least one aberration value with time as a result of lens heating or cooling. 18. The device manufacturing method according to claim 13, wherein the application-specific effect is determined on the basis of data indicative of the selected patterning device and an illumination mode used in the illuminating. 19. The device manufacturing method according to claim 13, wherein the generating is performed on the basis of known correspondence between changes in imaging adjustments of the adjustment system and the aberration changes being compensated for by such imaging adjustments. 20. The device manufacturing method according to claim 13, further comprising feeding back overlay metrology information to correct for a shift in a metrology overlay target for a current layer measured with respect to the metrology overlay target for a previous layer, as a result of said predicted changes and said adjusting, on the basis of an optimization procedure providing for changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. 21. The device manufacturing method according to claim 13, further comprising, re-measuring at least one aberration value when the predicted effect on the at least one parameter is greater than a corresponding threshold value. 22. The device manufacturing method according to claim 13, wherein the adjusting is carried out over successive scan positions during scanning exposure of the substrate to allow for variations in the scanned image over the extent of the substrate, in order to optimize the image as a function of scan position. 23. A machine readable medium encoded with machine executable instructions for performing a method comprising: predicting changes in projection aberrations with time with respect to measured aberration values for a required patterning application on a lithographic projection apparatus; determining an application-specific effect of said predicted projection aberration changes on at least one parameter of an image; generating a control signal specific to the required patterning application according to said predicted projection system aberration changes and their application-specific effect; and adjusting the imaging based on the control signal. | FIELD OF THE INVENTION This invention relates to lithographic projection apparatus and a device manufacturing method using such lithographic projection apparatus. BACKGROUND OF THE INVENTION The invention finds application, for example, in the field of lithographic projection apparatus incorporating a radiation system for supplying a projection beam of radiation, a support structure for supporting a patterning device, which serves to pattern the projection beam according to a desired pattern, a substrate table for holding a substrate; and a projection system for projecting the patterned beam onto a target portion of the substrate. The term “patterning device” as employed here should be broadly interpreted as referring to devices and structures that can be used to endow an incoming radiation beam with a patterned cross-section, corresponding to a pattern that is to be created in a target portion of the substrate; the term “light valve” can also be used in this context. Generally, the pattern will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit or other device (see below). Examples of such patterning devices include: A mask. The concept of a mask is well known in lithography, and it includes mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. Placement of such a mask in the radiation beam causes selective transmission (in the case of a transmission mask) or reflection (in the case of a reflective mask) of the radiation impinging on the mask, according to the pattern on the mask. In the case of a mask, the support structure will generally be a mask table, which ensures that the mask can be held at a desired position in the incoming radiation beam, and that it can be moved relative to the beam if so desired. A programmable mirror array. One example of such a device is a matrix-addressable surface having a visco-elastic control layer and a reflective surface. The basic principle behind such an apparatus is that (for example) addressed areas of the reflective surface reflect incident light as diffracted light, whereas unaddressed areas reflect incident light as non-diffracted light. Using an appropriate filter, the non-diffracted light can be filtered out of the reflected beam, leaving only the diffracted light behind; in this manner, the beam becomes patterned according to the addressing pattern of the matrix-addressable surface. An alternative embodiment of a programmable mirror array employs a matrix arrangement of tiny mirrors, each of which can be individually tilted about an axis by applying a suitable localized electric field, or by employing one or more piezoelectric actuators. Once again, the mirrors are matrix-addressable, such that addressed mirrors will reflect an incoming radiation beam in a different direction to unaddressed mirrors; in this manner, the reflected beam is patterned according to the addressing pattern of the matrix-addressable mirrors. The required matrix addressing can be performed using suitable electronic circuitry. In both of the situations described here above, the patterning device can comprise one or more programmable mirror arrays. More information on mirror arrays as here referred to can be gleaned, for example, from U.S. Pat. No. 5,296,891 and U.S. Pat. No. 5,523,193, and from WO 98/38597 and WO 98/33096, which are incorporated herein by reference. In the case of a programmable mirror array, the support structure may be embodied as a frame or table; for example, which may be fixed or movable as required. A programmable LCD array. An example of such a construction is given in U.S. Pat. No. 5,229,872, which is incorporated herein by reference. As above, the support structure in this case may be embodied as a frame or table, for example, which may be fixed or movable as required. For simplicity, parts of the rest of this specification are directed specifically to examples involving a mask and mask table; however, the general principles discussed in such instances should be seen in the broader context of the patterning device as set forth above. Lithographic projection apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, the patterning device may generate a circuit pattern corresponding to an individual layer of the IC, and this pattern can be imaged onto a target portion (e.g. comprising one or more dies) on a substrate (silicon wafer) that has been coated with a layer of radiation-sensitive material (resist). In general, a single wafer will contain a whole network of adjacent target portions that are successively irradiated via the projection system, one at a time. In current apparatus, employing patterning by a mask on a mask table, a distinction can be made between two different types of machine. In one type of lithographic projection apparatus, each target portion is irradiated by exposing the entire mask pattern onto the target portion in one go; such an apparatus is commonly referred to as a wafer stepper or step-and-repeat apparatus. In an alternative apparatus, commonly referred to as a step-and-scan apparatus, each target portion is irradiated by progressively scanning the mask pattern under the projection beam in a given reference direction (the “scanning” direction) while synchronously scanning the substrate table parallel or anti-parallel to this direction; since, in general, the projection system will have a magnification factor M (generally <1), the speed V at which the substrate table is scanned will be a factor M times that at which the mask table is scanned. More information on such lithographic devices is disclosed in U.S. Pat. No. 6,046,792, the contents of which are incorporated herein by reference. In a manufacturing process using a lithographic projection apparatus, a pattern (e.g. in a mask) is imaged onto a substrate that is at least partially covered by a layer of radiation-sensitive material (resist). Prior to this imaging step, the substrate may undergo various procedures, such as priming, resist coating and a soft bake. After exposure, the substrate may be subjected to other procedures, such as a post-exposure bake (PEB), development, a hard bake and measurement/inspection of the imaged features. This combination of processing steps is used as a basis for patterning of a single layer of the device which is for example an integrated circuit (IC). Such a patterned layer may then undergo various processes, such as etching, ion-implantation (doping), metallization, oxidation, chemical-mechanical polishing, etc., all of which are intended to finish off an individual layer. If several layers are required, then the whole procedure, or a variant thereof, will have to be repeated for each new layer. Eventually, an array of devices will be produced on the substrate (wafer). These devices are then separated from one another by a technique such as dicing or sawing, so that the individual devices can be mounted on a carrier, connected to pins, etc. Further information regarding such processing can be obtained, for example, from “Microchip Fabrication: A Practical Guide to Semiconductor Processing”, Third Edition, by Peter van Zant, McGraw Hill Publishing Co., 1997, ISBN 0-07-0672504, incorporated herein by reference. For simplicity, the projection system may hereinafter be referred to as the “lens”. However, this term should be broadly interpreted as encompassing various types of projection system, including refractive optics, reflective optics, and catadioptric systems, for example. The radiation system may also include components operating according to any of these design types for directing, shaping or controlling the projection beam of radiation, and such components may also be referred to below, collectively or singularly, as a “lens”. Furthermore, the lithographic apparatus may be of a type having two or more substrate tables (and/or two or more mask tables). In such “multiple stage” devices the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposures. Dual stage lithographic apparatus is described, for example, in U.S. Pat. No. 5,969,441 and WO 98/40791, the contents of both of which are incorporated herein by reference. Although specific reference may be made in this specification to the use of the apparatus according to the invention in the manufacture of integrated circuits, it should be explicitly understood that such an apparatus has many other possible applications. For example, it may be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, liquid-crystal display panels, thin-film magnetic heads, etc. The person skilled in the art will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” in this text should be considered as being replaced by the more general terms “substrate” and “target portion”, respectively. Generally, throughout the specification, any use of the term “mask” should be considered as encompassing within its scope the use of the term “reticle” In the present document, the terms “radiation” and “projection beam” are used to encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g. with a wavelength of 365, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range 5-20 nm). The phenomenon of lens heating can occur in the projection system of a lithographic projection apparatus. The projection lens becomes slightly heated by the projection beam radiation during exposures. As a result of this heating, refractive index changes occur, and a certain expansion of lens elements occurs, causing subtle changes in the geometric form of those elements, with an attendant change in their optical properties. This can result in the occurrence of new lens aberrations, or a change in existing aberrations. Because the occurrence of these aberration changes depends on such matters as the particular lens geometry, lens material, projection wavelength, light source power, target portion, wafer-reflectivity, size, and so on, the accuracy with which the effects of such lens heating can be predicted can be limited, especially in the absence of any measurement and compensating mechanism. Lens heating has always occurred to some extent in lithographic projection apparatus. However, with the trend to integrating an ever-increasing number of electronic components, and thus smaller features, in an IC, and to increase the manufacturing throughput, shorter wavelength radiation, such as EUV radiation has been used, as well as high-power radiation sources, such as 3-6 kW Mercury-arc lamps and excimer lasers with a power of 10 to 20 W, which together with the reduction in feature size have made lens heating a more serious problem. The problem is generally worse in scanners than in steppers because, in a stepper, substantially the whole (circular) cross-section of each lens element is irradiated, whereas, in a scanner, generally only a slit-shaped portion of the lens elements is irradiated; consequently, the effect in a scanner is far more differential than in a stepper, even if the lens aberrations in the scan direction are averaged out in the scanner, thereby resulting in the occurrence of new lens aberrations. The change in the optical properties of the elements of the projection system due to such lens heating naturally affects the image that is projected, principally by causing a change in the image parameters, of which magnification is particularly important for the XY-plane, and focus is particularly important for the Z-plane. However this lens heating effect can be calibrated and compensated for very well, e.g. by adjusting the positions of the lens elements to effect a compensating change in magnification or other image parameters of the projection system, for example as disclosed in EP 1164436A or U.S. Pat. No. 6,563,564, the contents of both of which are incorporated herein by reference. The lens heating effects depend on the lens properties, which are calibrated when the apparatus is constructed and may be recalibrated periodically thereafter, and various parameters of the exposures carried out, such as mask transmission, dose, illumination settings, field size and substrate reflectivity. When performing imaging in a lithographic projection apparatus, despite the great care with which the projection system is designed and the very high accuracy with which the system is manufactured and controlled during operation, the image can still be subject to aberrations, which can cause offsets in the image parameters for example, distortion (i.e. a non-uniform image displacement in the target portion at the image plane: the XY-plane), lateral image shift (i.e. a uniform image displacement in the target portion at the image plane), image rotation, and focal plane deformation (i.e. a non-uniform image displacement in the Z-direction, for instance, field curvature). It should be noted that, in general, image parameter offsets are not necessarily uniform, and can vary as a function of position in the image field. Distortion and focal plane deformation can lead to overlay and focus errors, for example overlay errors between different mask structures, and line-width errors. As the size of features to be imaged decreases, these errors can become intolerable. Consequently, it is desirable to provide compensation (such as adjustment of the projection system and/or substrate) to correct for, or at least attempt to minimize, these errors. This presents the problems of first measuring the errors and then calculating appropriate compensation. Previously, alignment systems were used to measure the displacements in the image field of alignment marks. However, alignment marks typically consist of relatively large features (of the order of a few microns), causing them to be very sensitive to specific aberrations of the projection system. The alignment marks are unrepresentative of the actual features being imaged, and because the imaging errors depend inter alia on feature size, the displacements measured and compensations calculated did not necessarily optimize the image for the desired features. Another problem occurs when, for instance, because of residual manufacturing errors, the projection system features an asymmetric variation of aberration over the field. These variations may be such that at the edge of the field the aberration becomes intolerable. A further problem occurs when using phase-shift masks (PSM's). Conventionally, the phase shift in such masks has to be precisely 180 degrees. The control of the phase is critical; deviation from 180 degrees is detrimental. PSM's, which are expensive to make, must be carefully inspected, and any masks with substantial deviation in phase shift from 180 degrees will generally be rejected. This leads to increased mask prices. A further problem occurs with the increasing requirements imposed on the control of critical dimension (CD). The critical dimension is the smallest width of a line or the smallest space between two lines permitted in the fabrication of a device. In particular the control of the uniformity of CD, the so-called CD uniformity, is of importance. In lithography, efforts to achieve better line width control and CD uniformity have recently led to the definition and study of particular error types occurring in features, as obtained upon exposure and processing. For instance, such image error types are an asymmetric distribution of CD over a target portion, an asymmetry of CD with respect to defocus (which results in a tilt of Bossung curves), asymmetries of CD within a feature comprising a plurality of bars (commonly referred to as Left-Right asymmetry), asymmetries of CD within a feature comprising either two or five bars (commonly known as L1-L2 and L1-L5, respectively), differences of CD between patterns that are substantially directed along two mutually orthogonal directions (for instance the so-called H-V lithographic error), and for instance a variation of CD within a feature, along a bar, commonly known as C-D. Just as the aberrations mentioned above, these errors are generally non-uniform over the field. For simplicity we will hereafter refer to any of these error types, including the errors such as, for example, distortion, lateral image shift, image rotation, and focal plane deformation, as lithographic errors, i.e. feature-deficiencies of relevance for the lithographer. Lithographic errors are caused by specific properties of the lithographic projection apparatus. For instance, the aberration of the projection system, or imperfections of the patterning devices and imperfections of patterns generated by the patterning devices, or imperfections of the projection beam may cause lithographic errors. However, also nominal properties (i.e. properties as designed) of the lithographic projection apparatus may cause unwanted lithographic errors. For instance, residual lens aberrations which are part of the nominal design may cause lithographic errors. For reference hereafter, we will refer to any such properties that may cause lithographic errors as “properties”. As mentioned above, the image of a pattern can be subject to aberrations of the projection system. A resulting variation of CD (for example, within a target portion) can be measured and subsequently be mapped to an effective aberration condition of the projection system which could produce said measured CD variation. A compensation can then be provided to the lithographic projection system such as to improve CD uniformity. Such a CD-control method is described in U.S. Pat. No. 6,115,108, incorporated herein by reference, and comprises imaging a plurality of test patterns at each field point of a plurality of field points, a subsequent processing of the exposed substrate, and a subsequent CD measurement for each of the imaged and processed test patterns. Consequently, the method is time consuming and not suitable for in-situ CD control. With increasing demands on throughput (i.e. the number of substrates that can be processed in a unit of time) as well as CD uniformity, the control, compensation and balancing of lithographic errors must be improved, and hence, there is the problem of furthering appropriate control of properties. U.S. Pat. No. 6,563,564 (P-0190) discloses a lens heating model by which projection system aberrations due to the lens heating effect can be corrected for by way of image parameter offset control signals that serve to adjust the image parameters of the projection system to compensate for the calculated change in the aberration effect due to such lens heating. In this case the change in the aberration effect with time is determined on the basis of a stored set of predetermined parameters corresponding to the selected aberration effect, these parameters can be obtained by a calibration step. The image parameter offsets may comprise focus drift, field curvature, magnification drift, third-order distortion, and combinations thereof. However, the required ideal compensation will depend on the particular application (the particular pattern, illumination mode, etc.), and the number of parameters that can be adjusted is generally not high enough to cancel out every aberration completely, so that the determination of the compensation to apply in a particular case will always be a compromise, the particular compromise to be chosen depending on the required application. Because the conventional lens heating model does not take into account the particular application, it follows that the calculated compensation will not be optimal for every particular application. EP 1251402A1 (P-0244) discloses an arrangement for compensating for projection system aberrations on the basis of the relationship between properties of the substrate, the layer of radiation sensitive material on the substrate, projection beam, the patterning device and the projection system, and the lithographic errors causing anomalies in the projected image. A control system determines a merit function which weighs and sums the lithographic errors, and calculates a compensation to apply to at least one of the substrate, the projection beam, the patterning device and the projection system to optimize the merit function. Although the use of such a merit function enables compensation to be applied in such a manner as to reach a reasonable compromise in terms of optimization of the image, it is found that, since such optimization is intended to provide the best compromise in terms of imaging quality over the whole of the image, the image quality in parts of the image or in particular applications may be relatively low. A control system may be provided for compensating for the effect of changes in a property of lithographic projection apparatus with time, such as the change in magnification of the projection system due to lens heating, in which a control signal is generated according to a predicted change in the property with time, a comparator compares a value based on the predicted change to a threshold, and generates a trigger signal when the value is greater than the threshold value, and the alignment system performs an alignment in response to the trigger signal. Such an arrangement triggers a so-called “realignment” when the predictive correction becomes larger than the desired maximum. This system therefore predicts the heating effects that will occur in performing a series of exposures and applies appropriate corrections in advance of the exposures being made when the corresponding threshold value is exceeded. This technique ensures that realignments occur only when errors are out of certain ranges, and avoids unnecessary realignments, thus avoiding loss of throughput in the exposure process. In certain applications errors in the predictive correction may result in unnecessary additional alignment steps and loss of throughput, since the optimal time for realignment is not calculated on the basis of the particular application. This could mean in practice that the imaging performance is worse than expected in a particular series of exposures, due to the realignment being triggered too late for the particular application; or the throughput is less than expected, due to the realignment being effected sooner than required in the series of exposures. SUMMARY OF THE INVENTION It is an object of the present invention to effect adjustments to the projection system of lithographic projection apparatus to compensate for the effect of lens aberrations in such a manner as to provide optimal image quality for a particular application, that is for a particular combination of mask (for example the product pattern) and illumination mode. According to the present invention there is provided lithographic projection apparatus including a radiation system for providing a beam of radiation, a support structure for supporting a patterning device for imparting a pattern to the projection beam, a substrate table for holding a substrate, a projection system for projecting the patterned beam onto a target portion of the substrate so as to produce an image of the patterning device on the target portion, a predictive system for predicting changes in projection system aberrations with time with respect to measured aberration values, a modelling system for determining the application-specific effect of said predicted projection system aberration changes on certain parameters of the image of a selected patterning device to be used in the apparatus for producing a specific required patterned beam, a control system for generating a control signal specific to the required patterned beam according to said predicted projection system aberration changes and their application-specific effect on certain parameters of the image, and an adjustment system for carrying out imaging adjustments in dependence on the control signal to compensate for the application-specific effect of said predicted projection system aberration changes on the image of the selected patterning device. In this specification the term “application” is used to denote the combination of the patterning device (the mask) and the illumination mode. In this regard the patterning device may be a conventional mask or reticle or a phase shift mask (PSM) and may be characterized by the feature size, the orientation, the density, etc. of the pattern to be produced on the product by the patterning device), and the illumination mode may be characterized by the numerical aperture (NA), the sigma inner/outer, the diffractive optical elements (DOE's), etc. This enables the aberrations to be compensated for, with precedence being given to those aberrations that are of most significance to the particular application (the particular pattern, illumination mode, etc.) in preference to aberrations that are of lesser significance in relation to that particular application. The appropriate adjustments to compensate for the aberrations that are appropriate to the particular application can then be determined and applied in such a manner to cancel out the effect of the aberrations optimally for the given application. For example, when the product pattern or part of the product pattern to be lithographically exposed has only horizontal lines as the features that require to be accurately defined by the lithographic exposure, such an arrangement will ensure that the effect of the aberrations of the projection system will be cancelled out optimally only for such horizontal lines and not for vertical lines. The fact that, in this example, the effect of the aberrations so far as hypothetical vertical lines are concerned is not compensated for optimally is immaterial since no such vertical lines require to be defined accurately in the product or the relevant part of the product. The adjustment system can be constituted by any suitable compensation scheme for compensating for the effect of the aberration changes. Methods of compensating for aberrations suitable for use with lithographic projection apparatus are, for instance, adjustments to fine position (an X-, Y-, and Z- translation, and a rotation about the X-, Y-, and Z-axis) of the holder for holding the patterning device, similar fine positioning of the substrate table, movements or deformation of optical elements (in particular, fine positioning using an X-, Y-, and Z- translation/rotation of optical elements of the projection system), and, for instance, methods and devices that change the energy of the radiation impinging on the target portion. However, suitable compensations are not limited to such examples; for instance, methods of changing the wavelength of the radiation beam, changes to the imaged pattern, changing the index of refraction of gas-filled spaces traversed by the projection beam, and changing the spatial distribution of the intensity of the radiation beam may also serve to effect the required compensation. The adjustment system may be adapted to adjust at least a selected one of: the position of the support structure along the optical axis of the projection system, the rotational orientation of the support structure, the position of the substrate table along said optical axis, the rotational orientation of the substrate table, the position along said optical axis of one or more movable lens elements comprised in said projection system, the degree of decentering with respect to said optical axis of one or more movable lens elements comprised in said projection system, the central wavelength of the projection beam, or saddle-like deformation of one or more lens elements comprised in said projection system using edge actuators. In one implementation of the invention the predictive system is arranged to determine the predicted projection system aberration changes with time on the basis of a lens heating model that predicts changes in at least one aberration value with time as a result of lens heating or cooling. Using an appropriate lens heating model it is possible for appropriate aberration offsets to be predicted in advance so that these aberration offsets can be used to determine the offsets in image parameters which can be used to calculate and thus apply appropriate (optimized with respect to a defined merit function) adjustments for the given application. In another implementation of the invention the modelling system is arranged to determine the application-specific effect of said projection system aberration changes on the basis of data indicative of the selected patterning device and the illumination mode of the projection system. The control system may use information on the aberrations of the projection system to adapt the settings of the projection system in such a way that certain distortions of the image are counteracted optimally. Both low-order aberrations, which cause image distortion effects that are independent of the optical path in the lens system to form the image, and high-order lens aberrations, which relate to distortion effects that depend on the optical path actually used in the lens system, can be corrected by such an arrangement. The control system may be arranged to generate a control signal which preferentially compensates predicted changes in features of the image in one direction in the plane of the image as compared with predicted changes in features of the image in another direction in the plane of the image, in accordance with the known sensitivities of the selected patterning device to projection system aberrations in the two directions. Furthermore the control system may be arranged to generate a control signal which preferentially compensates predicted changes in features of the image in the direction normal to the plane of the image, in accordance with the known sensitivities of the selected patterning device to projection system aberrations in said direction. The control signal can be generated in accordance with a defined merit function determining the relative weightings to be given to the effects of projection system aberrations on different parameters of the image, and in a particular embodiment, in accordance with a user-defined specification. The control system may be arranged to generate a control signal on the basis of known correspondence between changes in imaging adjustments of the adjustment system and the aberration changes being compensated for by such imaging adjustments. Additionally the control system may be arranged to generate a trigger signal to trigger measurement by a measurement system and adjustment by the adjustment system in response to such measurement when the predicted change in the image parameters with time is greater than a threshold value. One embodiment of the invention further includes overlay metrology feedback device for correcting for a shift in a metrology overlay target for a current layer measured with respect to the metrology overlay target for a previous layer, as a result of said predicted projection system aberration changes and the imaging adjustments effected to compensate for the application-specific effect of said predicted projection system aberration changes with respect to measured aberration values on certain parameters of the image, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. Another embodiment of the invention further includes a wafer alignment system for compensating for the effect of a shift in a respective wafer alignment mark provided for the alignment of each layer of successive layers of images to be applied to the target portion, as a result of said predicted projection system aberration changes and the imaging adjustments effected to compensate for the application-specific effect of said predicted projection system aberration changes with respect to measured aberration values on certain parameters of the image, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. Another embodiment of the invention further includes a mask alignment system for compensating for the effect of a shift in an image of a mask alignment mark provided for the alignment of the patterning device relative to the target portion, as a result of said predicted projection system aberration changes and the imaging adjustments effected to compensate for the application-specific effect of said predicted projection system aberration changes with respect to measured aberration values on certain parameters of the image, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. In one embodiment, the control system incorporates a realignment controller for re-measuring at least one aberration value when the predicted effect on one or more image parameters with time is greater than a corresponding (e.g. user-defined) threshold value. The use of thresholds for the lithographic parameters means that appropriate realignments are made only when these thresholds are exceeded, so that the effect on throughput is minimised whilst still keeping good imaging performance. In a development of the invention the adjustment system is arranged to carry out imaging adjustments over successive scan positions during scanning exposure of the substrate to allow for variations in the scanned image over the extent of the substrate in order to optimise the image as a function of scan position. This enables the optimal projection system adjustments to be varied as a function of the scan position (e.g. the Y-position of the scanner) during an exposure scan so as to enable the image quality to be optimised over the whole of the scan to compensate for variations in the image structure (for example horizontal lines in a first part of the product scanned and vertical lines in a subsequent part of the product scanned) in the scan direction. The invention further provides a device manufacturing method using lithographic projection apparatus, the method including providing a substrate having a target portion for receiving an image, selecting a patterning device in accordance with a required patterning application, using a projection system to project a selected beam of radiation onto the patterning device to produce a specific required patterned beam providing an image of the patterning device on the target portion, predicting changes in projection system aberrations with time with respect to measured aberration values, determining the application-specific effect of said predicted projection system aberration changes on certain parameters of the image of the selected patterning device to be used in the apparatus for producing the specific required patterned beam, generating a control signal specific to the required patterned beam according to said predicted projection system aberration changes and their application-specific effect on certain parameters of the image, and carrying out imaging adjustments in dependence on the control signal to compensate for the application-specific effect of said predicted changes in the aberrations on the image of the selected patterning device. Another aspect of an embodiment of the invention provides a data carrier incorporating a computer program for controlling a device manufacturing method using lithographic projection apparatus, the apparatus including a radiation system for providing a projection beam of radiation, a support structure for supporting patterning device for imparting a pattern to the projection beam, a substrate table for holding a substrate, and an adjustable projection system for projecting the patterned beam onto a target portion of the substrate so as to produce an image of the patterning device on the target portion, the computer program being arranged to effect a method including predicting changes in projection system aberrations with time with respect to measured aberration values, determining the application-specific effect of said predicted projection system aberration changes on certain parameters of the image of the selected patterning device to be used in the apparatus for producing the specific required patterned beam, generating a control signal specific to the required patterned beam according to said predicted projection system aberration changes and their application-specific effect on certain parameters of the image; and carrying out imaging adjustments in dependence on the control signal to compensate for the application-specific effect of said predicted changes in the aberrations on the image of the selected patterning device. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. 1 depicts lithographic projection apparatus for carrying the invention into effect; FIGS. 2 is an explanatory diagram showing the coupling between a lens heating model and an IQEA model; FIGS. 3 and 3a are explanatory diagram illustrating two practical implementations of the invention; and FIGS. 4 and 5 are flow charts of the control steps to be carried out in implementing particular embodiments in a computer system. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION FIG. 1 schematically depicts lithographic projection apparatus comprising at least one marker structure in accordance with an embodiment of the invention. The apparatus comprises: an illumination system IL for providing a projection beam PB of radiation (e.g. UV or EUV radiation). In this particular case, the radiation system also comprises a radiation source SO; a first support structure MT (e.g. a mask table) for supporting a patterning device, MA (e.g. a mask) and connected to first positioner (not shown) for accurately positioning the patterning device with respect to item PL; a second support structure WT (e.g. a wafer table) for holding a substrate, W (e.g. a resist-coated silicon wafer) and connected to second positioner PW for accurately positioning the substrate with respect to item PL; and a projection system PL (e.g. a reflective projection lens) for imaging a pattern imported to the projection beam PB by patterning device MA onto a target portion C (e.g. comprising one or more dies) of the substrate W. The projection system PL is provided with an actuating device AD for adapting the optical settings of the system. The operation of adapting the optical settings will be explained hereinafter in more detail. As depicted here, the apparatus is of a transmissive type (i.e. has a transmissive mask). However the apparatus may alternatively be of a reflective type (with a reflective mask). Alternatively the apparatus may employ another kind of patterning device, such as a programmable mirror array of a type as referred to above. The source SO (e.g. a mercury lamp or an excimer laser) produces a beam of radiation. This beam is fed into an illumination system (illuminator) IL, either directly or after having traversed a beam conditioner, such as a beam expander Ex, for example. The illumination system IL may comprise adjustable optical element AM for setting the outer and/or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution of the beam PB. In addition, it will generally comprise various other components, such as an integrator IN and a condenser CO. In this way, the beam PB impinging on the mask MA has a desired uniformity and intensity distribution in its cross-section. It should be noted with regard to FIG. 1 that the source SO may be within the housing of the lithographic projection apparatus (as is often the case when the source SO is a mercury lamp, for example), but that the source SO may also be remote from the lithographic projection apparatus, the beam which it produces being led into the apparatus (e.g. with the aid of suitable directing mirrors). This latter scenario is often the case when the source SO is an excimer laser. The present invention is applicable to both of these scenarios. The beam PB is incident on the mask MA, which is held on the mask table MT. Having traversed the mask MA, the beam PB passes through the lens PL, which focuses the beam PB onto a target portion C of the substrate W. With the aid of the second positioner PW and interferometer IF, the substrate table WT can be moved accurately, e.g. so as to position different target portions C in the path of the beam PB. Similarly, the first positioner (acting on the mask table MT) can be used to accurately position the mask MA with respect to the path of the beam PB, e.g. after mechanical retrieval of the mask MA from a mask library, or during a scan. In general, movement of the object tables MT, WT will be realised with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which are not explicitly shown in FIG. 1. However, in the case of a wafer stepper (as opposed to a step-and-scan apparatus) the mask table MT may just be connected to a short stroke actuator, or may be fixed. Mask MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. The depicted apparatus can be used in two different modes: 1. In step mode, the mask table MT and the substrate table WT are kept essentially stationary, and an entire pattern imported to the beam PB is projected in one go (i.e. a single “flash”) onto a target portion C. The substrate table WT is then shifted in the X and/or Y directions so that a different target portion C can be irradiated by the beam PB. 2. In scan mode, essentially the same scenario applies, except that a given target portion C is not exposed in a single “flash”. Instead, the mask table MT is movable in a given direction (the so-called “scan direction”, e.g. the Y-direction) with a speed v, so that the projection beam PB is caused to scan over a mask image; concurrently, the substrate table WT is simultaneously moved in the same or opposite direction at a speed V=M v, in which M is the magnification of the lens PL (typically, M=¼ or ⅕). In this manner, a relatively large target portion C can be exposed, without having to compromise on resolution. 3. In another mode, the mask table MT is kept essentially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the projection beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is employed and the programmable patterning device is updated as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes a programmable patterning device, such as a programmable mirror array of a type as referred to above. Combinations and/or variations on the above described modes of use or entirely different modes of use may also be employed. In a non-illustrated variant embodiment the substrate table is replaced by a twin-stage arrangement comprising two substrate tables to which the wafers are supplied so that, whilst one of the wafers is being exposed in one or other of the different modes described above, another of the wafers is being subjected to the necessary measurements to be carried out prior to exposure, with a view to decreasing the amount of time that each wafer is within the exposure zone and thus increasing the throughput of the apparatus. The interferometer typically can comprise a light source, such as a laser (not shown), and one or more interferometers for determining some information (e.g. position, alignment, etc.) regarding an object to be measured, such as a substrate or a stage. In FIG. 1, a single interferometer IF is schematically depicted by way of example. The light source (laser) produces a metrology beam MB which is routed to the interferometer IF by one or more beam manipulators. In the case where more than one interferometer is present, the metrology beam is shared between them, by using optics that split the metrology beam into separate beams for the different interferometers. A substrate alignment system MS for alignment of a substrate on the table WT with a mask on the mask table MT, is schematically shown at an exemplary location close to the table WT, and comprises at least one light source which generates a light beam aimed at a marker structure on the substrate W and at least one sensor device which detects an optical signal from that marker structure. It is to be noted that the location of the substrate alignment system MS depends on design conditions which may vary with the actual type of lithographic projection apparatus. Furthermore the lithographic projection apparatus comprises an electronic control system in the form of a computer arrangement which is capable of controlling and adjusting machine parameters during execution of a series of imaging and exposure steps during processing of a lot of wafers using a common mask. The computer arrangement as used in an embodiment of the invention comprises a host processor connected to memory units which store instructions and data, one or more reading units for reading CD ROM's for example, input devices such as a keyboard and a mouse, and output devices such as a monitor and a printer. An input/output (I/O) device is also connected to the lithographic projection apparatus for handling control signals transmitted to and received from actuators and sensors, which take part in controlling of the projection system PL in accordance with the present invention. As explained previously, when the projection beam radiation PB passes through the projection lens system PL, part of it is absorbed in lens elements and coating materials. This partial absorption causes global and local temperature and refractive index changes in the lens elements. This results in changes in the optical performance of the lens, which can be characterized as lens aberration. The overall aberration can be decomposed into a number of different types of aberration, such as spherical aberration, astigmatism and so on. The overall aberration is the sum of these different aberrations, each with a particular magnitude given by a coefficient. Aberration results in a deformation in the wave front and different types of aberration represent different functions by which the wave front is deformed. These functions may take the form of the product of a polynomial in the radial position r and an angular function in sine or cosine of mθ, where r and θ are polar coordinates and m is an integer. One such functional expansion is the Zernike expansion in which each Zernike polynomial represents a different type of aberration and the contribution of each aberration is given by a Zernike coefficient, as will be described in more detail below. Particular types of aberration, such as focus drift and aberrations with even values of m (or m=0) in the angular functions dependent on mθ, can be compensated for by way of image parameters for effecting adjustment of the apparatus in such a manner as to displace the projected image in the vertical (z) direction. Other aberrations, such as coma, and aberrations with an odd value of m can be compensated for by way of image parameters for effecting adjustment of the apparatus in such a manner as to produce a lateral shift in the image position in the horizontal plane (the x,y-plane). The best-focus (BF) position, i.e. z-position of the image, can be measured using the actual lithographic projection apparatus. The best-focus position is the z-position with maximum contrast, for example the position as defined by the maximum of a sixth-order polynomial fit to the contrast-versus-position curve as the position is moved from defocus, through focus and on to defocus. The best-focus can be determined experimentally using known techniques, such as the technique known as “FOCAL” (described below); alternatively, one may directly measure the aerial image, for example by using a transmission image sensor (TIS) (described below) or commercial focus monitor. FOCAL is an acronym for focus calibration by using alignment. It is a best-focus measurement technique for completely determining information about the focal plane using the alignment system of the lithographic apparatus. A special, asymmetrically segmented alignment mark is imaged through focus on to a resist coated wafer. The position of this imaged mark (latent or developed) can be measured by the alignment system. Due to the asymmetric segmentation, the position measured by the alignment system will depend on the defocus used during exposure, thus allowing determination of the best-focus position. By distributing these marks over the whole image field and using different orientation for the segmentation, the complete focal plane for several structure orientations can be measured. This technique is described in more detail in U.S. Pat. No. 5,674,650 incorporated herein by reference. One or more transmission image sensors (TIS) can be used to determine the lateral position and best focus position (i.e. horizontal and vertical position) of the projected image from the mask under the projection lens. A transmission image sensor (TIS) is inset into a physical reference surface associated with the substrate table (WT). To determine the position of the focal plane, the projection lens projects into space an image of a pattern provided on the mask MA (or on a mask table fiducial plate) and having contrasting light and dark regions. The substrate stage is then scanned horizontally (in one or possibly two directions, e.g. the x and y directions) and vertically so that the aperture of the TIS passes through the space where the aerial image is expected to be. As the TIS aperture passes through the light and dark portions of the image of the TIS pattern, the output of the photodetector will fluctuate (a Moiré effect). The vertical level at which the rate of change of amplitude of the photodetector output is highest indicates the level at which the image of TIS pattern has the greatest contrast and hence indicates the plane of optimum focus. The x, y-positions of the TIS aperture at which the rate of change of amplitude of the photodetector output during said horizontal scan is highest, are indicative of the aerial lateral position of the image. An example of a TIS detection arrangement of this type is described in greater detail in U.S. Pat. No. 4,540,277 incorporated herein by reference. The measurement of other imaging parameters is described in U.S. Pat. No. 6,563,564. Other techniques can also be used to analyze the image. For example, a so-called ILIAS sensing arrangement as described in WO 01/63233 may be used. From these measurements of the image position, it is possible to obtain the Zernike coefficients of the different forms of aberration. This is explained more fully in, for example, European Patent Application No. EP 1128217A2 incorporated herein by reference. The lens heating effect is also in general dependent on parameters such as the illumination setting, mask transmission, mask structure, field size and shape, light intensity, wafer reflectivity and wafer layout, so it is difficult to calculate from first principles and is generally empirical. The lens heating effect also varies dynamically with time, and so, in order to correct for this lens heating effect, the present embodiment employs a model of the effects of lens heating based on previous measurements, optionally calibrates and fine tunes the model using intermittent measurements, and makes adjustments to the lithographic projection apparatus to keep the lithographic parameters within their respective tolerances. Considering the aberration effect known as focus drift caused by lens heating, the model employed in this first embodiment is as follows. F(t)=A1(1−e−/t1)+A2(1−e−1/t2) Thus the drift F as a function of time t, i.e. the change in best focus position in the z-direction relative to its position at t−0, is described by two exponential functions and this has been found to be a good model. Each of the exponential functions has a time-constant, τ1 and τ2 respectively, and each has an amplitude, A1 and A2 respectively. The values of the amplitudes and time constants depend on at least a subset of the parameters of illumination setting, mask transmission, mask structure, field size and shape, radiation intensity, wafer reflectivity and wafer layout. The model of this embodiment further assumes a linear dependency of the amplitudes on some of these parameters, and particularly those proportional to the power incident on the lens, such as the light intensity, field size, mask transmission factor and wafer reflectivity, such that the amplitudes may be written as: A1=μ1.Tr.S.I.Wrefl A2=μ2.Tr.S.I.Wrefl where I is the exposure light intensity (W/m2), S is the field size or masking area at wafer level (m2), Tr is the mask transmission factor, Wrefl is the wafer reflectivity (a pure fraction or percentage), and μ1,2 are so-called scaling factors, which are phenomenological and depend on all the other parameters that affect lens heating but that are not specifically included. In this way, a lens heating database is built up which stores the image parameter values needed to correct for lens heating, and which in this embodiment consists of two time constants (τ1 and τ2) and two scaling factors (μ1 and μ2). A set of these image parameters can be stored for each mask and illumination setting of interest. The technique has been described above in terms of focus drift purely as an example of one type of image parameter. Sets of image parameters can also be built up and stored in the database that characterize the change in different aberrations, such as astigmatism and coma, as a function of lens heating (time). The aberrations may depend strongly on the particular mask structure being exposed, and therefore fine tuning measurements can be made using a particular mask to obtain values of these image parameters for different aberrations prior to exposing a particular lot of wafers using that mask. Any mask-specific mask heating effects can also be included in the model. Having obtained and installed a database of parameters defining the lens heating effect, software is used in a feed forward technique to predict the necessary correction that needs to be made to overcome the effects on image parameters of the aberrations calculated according to the model. This is done for every exposure, and physical adjustments to compensate for the calculated image parameter offsets that need to be corrected can be made immediately before each exposure. To compensate for variations in heating effects between different masks and at different illumination settings for which fine-tuned parameters have not necessarily been obtained, occasional measurements can also be made intermittently during a lot to dynamically adjust the model. New optimum time constant and/or scaling factor parameters can be calculated after each new measurement by a fit based on for instance a minimization of the residue R. Also, when performing exposures at settings for which parameter values are not available, interpolation or extrapolation from known parameters can be used to give a best estimate for the parameter values to be used for the new setting. At a particular time, a calculation for each type of aberration effect will give the predicted additional amount of that aberration effect resulting from lens heating, over and above any intrinsic aberration effect, i.e. the default value for the lens. The correction to make to the lithographic projection apparatus in terms of adjustments to be made to the apparatus by way of adjustment signals to further compensate for the lens heating effect depends on each particular type of aberration or image parameter as follows: Focus drift—adjust substrate table height Field curvature—shift one or more movable lens elements along the optical axis Magnification drift—shift one or more movable lens elements along the optical axis and adjust axial position of mask along the optical axis Third-order distortion—adjust axial position of mask along the optical axis and shift one or more movable lens elements along the optical axis Spherical aberration—shift one or more movable lens elements along the optical axis Comatic aberration—shift the central wavelength of the exposure radiation and adjust the degree of decentering with respect to the optical axis of one or more movable lens elements. It should be noted that the relationships between the aberrations and the required adjustments to the lithographic projection apparatus may differ for different types of lens. The correction can be performed automatically by the machine, based on tabulated or calculated image parameter values relating the magnitude of the aberration effect to the size of the mechanical adjustment necessary. Saddle-like deformation of one or more lens elements to correct for particular aberrations is described, for example, in WO 99/67683 incorporated herein by reference. The contribution of each aberration effect will depend on the mask being exposed and the illumination setting. Therefore it will not always be necessary to make adjustments for all of these aberration effects for every exposure or lot of exposures. The projection system PL is provided with an actuating device AD which is capable of adapting the optical settings of the projection system by way of adjustment signals supplied to the optical elements within the projection system PL in accordance with the calculated image parameters. The actuating device AD is provided with input and output ports for exchanging control signals with the computer arrangement. The computer arrangement is used to manipulate data using a combination of a lens heating model 10 and an IQEA model 11 (where IQEA denotes image quality effects of aberrations), as shown in the data flow diagram of FIG. 2. The lens heating model (which may be, for example, as described in U.S. Pat. No. 6,563,564) is a dynamic model which predicts changes in the aberrations, that is the aberration offset data, with time due to heating of the lens, and which receives as input data indicative of the particular application, such as the product pattern, the illumination mode, etc., as well as data indicative of the exposure history, that is the data indicative of the timestamp, dose, image size, reticle transmission, etc. of each of the exposures that have previously been carried out in the lot, and the current time. The lens heating model provides aberration offset output signals (expressed in Zernikes). The IQEA model also receives data indicative of the particular application(product pattern, illumination mode) and the user-defined lithographic specification, as well as aberration offset data indicative of the predicted aberration changes from the lens heating model, and provides output signals indicative of the image parameter offsets, such as distortions in the X-Y plane, deviations in the Z plane, and offsets in other image parameters, e.g. astigmatism. Such image parameter offset output signals effect the required adjustments to compensate for the aberrations of most relevance to the particular application, such adjustments being effected by way of adjustment signals supplied to one or more lenses of the projection system, and/or other adjustable parts of the apparatus, such as the substrate table, depending on the aberrations to be compensated for to optimize the overlay and imaging performance of the lithographic projection apparatus. Such image parameter offset output signals will vary with time by virtue of the fact that the aberration values outputted by the lens heating model will vary with time, and may serve to adjust for distortions in the XY-plane, deviations in the Z-plane normal to the XY-plane, or to adjust for offsets in more general imaging parameters, e.g. on-axis astigmatism. Other image parameter output signals may serve to adjust the CD or L1L2 for example. In a further implementation, as shown in the data flow diagram of FIG. 3, the lens heating model 10 and the IQEA model 11 are combined with.a lens model 12 and optimizer 13. The lens model 12 (not to be confused with the lens heating model 10) provides an indication of the setting of the various lens adjustment elements that will give optimal lithographic performance for the particular lens arrangement used as will be described in more detail below, and can be used together with the IQEA model (and the predicted aberration offsets from the lens heating model) to optimize the overlay and imaging performance of the lithographic apparatus during exposure of a lot of wafers. To this end the predicted image parameter offsets (overlay, focus, etcfrom the IQEA model 11 are supplied to the optimizer 13 which determines the adjustment signals for which the remaining offsets in the image parameters will be minimized according to the user-defined lithographic specification (which will include for example the relative weighting to be allotted to overlay errors and focus errors and will determine to what extent the maximum allowed value for the overlay error (dX) over the slit for example will be counted in the merit function indicating optimal image quality as compared with the maximum allowed value for the focus error (dF) over the slit). The parameters of the lens model 12 are calibrated off-line. During an optimization phase the adjustment signals are supplied by the optimizer 13 to the lens model 12 which determines the aberrations that would be induced in the lens if such adjustment signals were supplied to the lens. These induced aberrations are supplied to an adder 14 along with the predicted aberrations offsets from the lens heating model 10 and any measured aberration values; such that only the remaining aberrations are fed back to the IQEA model 11. The measured aberration values are supplied as a result of the previously described measurements at the start of the lot, and the aberration offsets with respect to the last measured values are predicted by the lens heating model 10. Following such optimization of the image parameters, the resultant adjustment signals are supplied to the lens 15 or other adjustable element to effect the necessary compensating adjustments prior to exposure of the wafers. FIG. 3a is a diagram of a modification of such an implementation in which a combination 17 of a lens model and a linearised IQEA model is provided to enable optimization of the adjustment signals in accordance with the user-defined lithographic specification to be implemented in one run (rather than separate runs having to be carried out for each of the image parameters to be optimized). The linearised IQEA model is derived from the IQEA model 11 as described in more detail below with reference to two possible methods for combining the lens model and a linearised IQEA model. In this case the optimised adjustment signals are supplied directly to the lens 15 or other adjustable element to effect the necessary compensating adjustments prior to exposure of the wafers, without it being necessary to feed back induced aberration values corresponding to the adjustment signals in the manner previously described. The overall aberration can be decomposed into a number of different types of aberration, such as spherical aberration, astigmatism and so on. The overall aberration is the sum of these different aberrations, each with a particular magnitude given by a coefficient. Aberration results in a deformation in the wave front and different types of aberration represent different functions by which the wave front is deformed. These functions may take the form of the product of a polynomial in the radial position r and an angular function in sine or cosine of mθ, where r and θ are polar coordinates and m is an integer. One such functional expansion is the Zernike expansion in which each Zernike polynomial represents a different type of aberration and the contribution of each aberration is given by a Zernike coefficient: W ( ρ , θ ) = ∑ n = 0 N ∑ t = - n step 2 n A n , l · R n l ( ρ ) · e i · l · θ ( 1 ) where W is the phase distribution in the pupil plane, as function of position in the pupil [nm] An,l is the aberration or Zernike coefficient [nm] Rnl is a polynomial of order n, and dependent on 1. ρ is the radius in the pupil plane [units of NA] θ is the angle in the pupil [rad] n is the power of ρ (0≦n≦N) N is the order of the pupil expansion 1 is the order of θ (n+1=even and −n≦1≦n) The aberration coefficient An,1 is usually written as Zernike coefficient Zi An,l=ai·Zi , (2) where ai is a scaling factor i is n2+n+l+1 The aberrations and thus also the Zernike coefficients are a function of the position in the image plane: Zi=Zi(X,Y). However, in a scanner the aberrations in the y-direction are averaged out during the scanned exposure, so that Zi(X,Y) becomes {overscore (Z)}i (X) (which is usually just referred to as Zi(X)). The function of the aberrations (Zernike coefficient) across the image plane can in turn be described by a simple series expansion: Zi(X)=Zi—0+Zi—1·X+Zi—2·X2+Zi—3·X3+Zi—res (X), (3) where Zi(X) is described as the sum of a constant term (with coefficient Zi—0), a linear term (with coefficient Zi—1), etc. and a remaining term or residuals (Zi—res). The linear and third order terms of the low order odd aberrations (Z2—1, Z2—3) are referred to as the magnification and third order distortion. However, there are also for instance linear terms of higher order odd aberrations (eg. Z7—1 or coma tilt) which have a magnification effect (but depending on the exposed image, illumination setting and mask type). The second order of the lower order even aberration (Z4—2) is usually referred to as the field curvature. The lens model is used to calculate the lens settings (adjustable lens element positions and tilts) that give optimal lithographic performance. For instance the lens of one particular system is able to adjust the following parameters: Z2—1, Z2—3, Z4—2, Z7—1, Z913 0, Z14—1, Z16—0 The following equations represent a simplified example of the lens model: Z2—1=A*E1+B*E2+C*E3 Z7—1=D*E1+F*E2+G*E3 Z9—0=H*E1+K*E2+N*E3 Z14—1=P*E1+Q*E2+R*E3 (4) or in matrix notation: Z _ adj = ( Z 2 — 1 Z 7 — 1 Z 9 — 0 Z 14 — 1 ) = ( A B C D F G H K N P Q R ) · ( E 1 E 2 E 3 ) = M · E _ ( 5 ) where M is the dependencies matrix and {overscore (E)} is the lens element vector A simulator uses the IQEA model to determine, from the characteristics of the product features and the illumination settings used, the so-called sensitivities (Si) for the different aberration coefficients (Zi) and these sensitivities constitute the linearised IQEA_model. This is done by using commercial packages, such as Prolith, Solid-C or Lithocruiser (from ASML Masktools), that are able to calculate the projected aerial image based on the characteristics of the feature, the illumination setting, and the lens type and aberrations. From the aerial image the relevant lithographic errors can be calculated, such as X-displacement (the distribution of X- and Y-displacement errors being usually referred to as distortion), Z-displacement (called defocus and the distribution of Z-displacement errors being usually referred as focal plane deviation), C-D difference (critical dimension difference for brick-wall features), left-right asymmetry, H-V litho errors, etc. The sensitivities are calculated by dividing the calculated error by the amount of aberration put into the simulator. This is done for all the relevant lithographic errors and aberrations (expressed in Zernikes). By multiplying the calculated sensitivities by the aberrations of the lens, the lithographic errors of the system are obtained across the image field (scanner slit). For example, an overlay error is the X-distortion (dx), and the X-distortion of a certain feature exposed with a certain illumination setting becomes: dx ( X ) = ∑ i Z i ( X ) · S i ( i = 2 , 7 , 10 , 14 , 19 , 23 , 26 , 30 and 34 ) . ( 6 ) And the defocus (dF) across the slit (for a vertical feature) becomes: dF ( X ) = ∑ i Z i ( X ) · S i ( i = 4 , 5 , 9 , 12 , 16 , 17 , 21 , 25 , 28 , 32 and 36 ) . ( 7 ) Depending on the user defined lithographic specification, other lithographic errors also need to be taken into account. In general most lithographic errors can be written as: E ( X ) = ∑ i Z i ( X ) · S i ( i = 2 , 3 , … 36 ) . ( 8 ) If the lens model is used without also applying the IQEA model, all the aberrations (in this example Z2—1, Z7—1, Z9—0 and Z14—1) are optimised at the same time. Because there are less lens elements to adjust than there are parameters to optimise, the total system may be placed in the optimum state but the individual image parameters may not be optimal for the particular application. Furthermore the optimal state for all tunable parameters together might not give the optimal performance. By combining the IQEA model with the lens model, it is possible to make the correction-method much more flexible and powerful (it can be optimised for the appropriate applications). Two possible methods for combining the lens model and the IQEA model are discussed below: The simplest method for combining the two models is by applying the calculated sensitivities (Si) from the IQEA model in the lens model: Z _ adj ′ = ( Z 2 — 1 ′ Z 7 — 1 ′ Z 9 — 0 ′ Z 14 — 1 ′ ) = ( Z 2 — 1 · S 2 Z 7 — 1 · S 7 Z 9 — 0 · S 9 Z 14 — 1 · S 14 ) = ( A · S 2 B · S 2 C · S 2 D · S 7 F · S 7 G · S 7 H · S 9 K · S 9 N · S 9 P · S 14 Q · S 14 R · S 14 ) · ( E 1 E 2 E 3 ) = M ′ · E _ ( 9 ) If for example S14=0, the equations become exactly solvable. However, even if none of the sensitivities is zero, the highest sensitivities will get more weight in the final solution, resulting in an state of the system which is optimal for the particular application. The second method for combining the two models is to optimise the system to one or more lithographic performance indicators. In one possible example the system is optimised for the performance indicator X-distortion (dx) in which case the IQEA model equation for this indicator can be written in the following manner: dx ( X ) = ∑ i Z i ( X ) · S i = ∑ i ( Z i — 0 + Z i — 1 · X + Z i — res ( X ) ) · S i = ∑ i Z i — 1 · S i · X + ∑ i ( Z i — 0 + Z i — res ( X ) ) · S i = ( Z 2 — 1 · S 2 + Z 7 — 1 · S 7 + Z 14 — 1 · S 14 ) · X + ∑ r Z r — 1 · S r · X + ∑ i ( Z i — 0 + Z i — res ( X ) ) · S i = ( Z 2 — 1 · S 2 + Z 7 — 1 · S 7 + Z 14 — 1 · S 14 ) · X + residuals ( 10 ) where i=2, 7, 10, 14, 19, 23, 26, 30 and 34 and r=10, 19, 23, 26, 30 and 34 If the expressions for the lens adjustments are used for the three linear aberration terms (Z2—1, Z7—1, Z14—1) in this equation, it becomes: dx ( X ) = ( Z 2 — 1 · S 2 + Z 7 — 1 · S 7 + Z 14 — 1 · S 14 ) · X + residuals = ( A · E 1 + B · E 2 + C · E 3 ) · S 2 + ( D · E 1 + F · E 2 + G · E 3 ) · S 7 + + ( P · E 1 + Q · E 2 + R · E 3 ) · S 14 + residuals ( 11 ) This equation constitutes the integrated lens model equation which needs to be solved. In reality there will be more lithographic errors that have to be optimised at the same time, making the solution more complex. For instance, if there is a requirement to optimise the defocus (dF), the second equation to be solved becomes: dF ( X ) = Z 9 — 0 · S 9 + residuals = ( H * E 1 + K * E 2 + N * E 3 ) · S 9 + residuals ( 12 ) In this case both dx and dF need to become minimized by adjusting the lens elements. In cases where there are an excess number of degrees of freedom, it is sensible to use this to make individual adjustable aberrations as small as possible, in order to make the general performance of the system as good as possible. The computer arrangement is capable of controlling and adjusting the settings of the projection system, as shown by the flow chart of FIG. 4, in such a way that, during each exposure in a sequence of multiple die exposures of a lot of wafers, the changes in the aberrations due to lens heating which the particular application is most sensitive to are compensated for optimally for the exposure of each successive die of each wafer. Therefore, at the start of the exposure of the lot of wafers as indicated by the start lot box 20, a lot correction procedure 21 is performed in which, prior to the sequence of exposures of the lot, the aberrations of the image are measured, for example, by the ILIAS or TIS technique to provide measured aberration data 22. The resulting aberration values are supplied to the IQEA model as described in more detail below. The lens heating model is then used in a processing step 23 to predict the aberration offset data 24 due to lens heating for each successive exposure, the lens heating model receiving data indicative of the exposure history (e.g. the number of earlier exposures in the lot, and their time stamps). Such aberration offset prediction is performed for each successive exposure in the lot on the basis of predicted changes in the aberrations with respect to the last lot correction in advance of actual exposure. In a processing step 25 an IQEA model receives measured aberration data 22 and the aberration offset data 24, as well as the application data 26, that is the data indicative of the particular application, such as the illumination mode (e.g. numerical aperture, sigma inner and outer), the features to be defined in the product with high accuracy (e.g. feature size, density), the dose of radiation to be applied during the exposure, the mask transmission, etc., and data 28 indicative of the user defined lithographic specification defining the sensitivities of different features to different aberration types. The IQEA model together with an appropriate optimiser determines from this data the modeled image parameter offsets, for adjustment of the appropriate settings, such as overlay values (X-Y adjustment), focus values (Z adjustment), for optimising the imaging performance for each exposure as will be described below. The appropriate die on the wafer is then exposed with these settings in a processing step 30, and it is determined at 31 whether or not the last die of the image has been exposed, and a control signal transmitted to initiate the processing step 23 for the next die of the image where appropriate. In the event that all the dies of the image have been exposed, it is determined at 32 whether or not the last image of the wafer has been exposed, and a control signal transmitted to initiate the series of processing steps 23 for the next image where appropriate. In the event that all the images of the wafer have been exposed, it is determined at 33 whether or not the last wafer of the lot has been exposed, and a control signal transmitted to to signal the end of the exposure of the lot of wafers, as indicated at 34. In a variant of this embodiment a realignment procedure is performed in which the positions of four alignment markers on the mask are detected, and, in the event that one or more of the image parameter offsets exceeds a threshold, some of the image parameters, such as the magnification for example, are remeasured with the result that these particular image parameters will be measured more frequently than just once at the start of a lot. Since such realignment is done on markers on the mask, which are separate from the product pattern, care must be taken to ensure that the remaining aberrations do not adversely affect measurement of the markers during such realignment. In this regard the IQEA model can be used to predict the image parameter offsets that are of most relevance to the detection of the markers on the mask in order to enable the corresponding aberrations to be compensated for so that they do not adversely affect measurement of the markers during the realignment. Whilst it is advantageous to incorporate such a realignment procedure in the control and adjustment of the settings of the projection system, it should be appreciated that the use of such a procedure is optional and that effective control and adjustment of the projection system settings is also possible in the absence of any realignment procedure. FIG. 5 is a flow chart of an alternative method for controlling and adjusting the settings of the projection system, with the differences over the flow chart of FIG. 3 being shown in bold In this case a lens heating feedback system is provided in which the predicted aberration offset data 24 and application data 26 are inputted into the IQEA model in a processing step 35 so that, prior to the exposure of a further image on a wafer or a further wafer, the predicted image parameter offsets are compared at 36 to threshold data held at 36. In the event that one or more of the image parameter offset values exceeds the corresponding threshold value, a feedback control signal is supplied to cause the aberrations of the image to be remeasured in a further measurement step, so that such newly measured aberration values are used in determination of the total aberration values to be used in the calculation of the image parameter offsets for controlling the optimal lens settings for the exposure of the next image or wafer, in place of the previously measured aberration values. The exposure of each image on each wafer is controlled in similar manner with the optimal lens settings being adjusted for each image where necessary to take account of further heating of the lens, and realignment (by remeasurement of the aberrations) occurring only when necessary as determined by the predicted image parameter offsets exceeding the threshold values. In this manner the imaging and overlay performance of the apparatus is optimized for the particular application and to compensate for the effect of lens heating whilst ensuring that realignment, and the consequent decrease in throughput, occurs only when necessary. This is achieved by controlling the applied corrections according to the application and particularly in dependence on the features of the critical structures of the product, such as the gates of transistors in the front end layer of a wafer for example. The procedure for these computations will be explained in more detail below. As a first step the lens aberrations measured for the projection system need to be described, for example in terms of Zernike coefficients. A linear estimation computation model is used that implements an adaptation of projection system settings based on a linear combination of the sensitivities of the image to distortion with respect to all of the Zernike coefficients. Basically, a distortion of an ideal pattern feature with a given ideal centroid position will relatively shift the centroid position. For the different types of distortion as defined by the Zernike coefficients, the sensitivities of a given pattern feature to distortion will differ, but can be calculated based on a distortion map depending on a “co-ordinate by co-ordinate” or “slit co-ordinate” based approach. Furthermore, the sensitivity to a given distortion type varies with the shape of the (basic) pattern feature to be imaged. Therefore the linear estimation computation model computes (for example in an off-line mode) the aberration induced distortion parameters for a variety of pattern features (variation of shape and size) in combination with the local lens aberrations of the projection system. Also, the illumination mode and mask type (i.e. the pupil plane filling) is taken into account. Using the linear estimation computation model the distortion (dx, dy) on a co-ordinate (x, y) is described by: dx ( x , y ) = ∑ i = 7 , 10 , 14 , … Z i ( x , y ) · S i dy ( x , y ) = ∑ i = 8 , 11 , 15 , … Z i ( x , y ) · S i where Zi is a Zernike coefficient of ith order, Si is a sensitivity coefficient for a given Zernike coefficient Zi, with the x-distortion and the y-distortion each being described by a series of Zernike coefficients. The Zernike coefficients depend on the x, y coordinate. The sensitivities Si basically depend on the pattern, and the illumination mode. The results of the computations of these equations are stored in the memory of the computer arrangement 8 in one or more databases as imaging correction data. The imaging correction data can be determined for any given combination of pattern feature type and size, and pupil plane filling. The one or more databases may hold imaging correction data as a function of each of such combinations. During the lithographic processing run, the imaging correction data is retrieved from the memory. The projection system settings are adapted in accordance with a combination of pattern distortion parameters, namely the type and size of the pattern feature to be imaged, the actual lens aberrations co-ordinate and the actual pupil plane filling for that pattern feature. The imaging correction data (based on the combination of actual pattern distortion parameters) can be made available from the database through information in the job data file for the processing run to an on-line adaptation procedure. The on-line adaptation procedure adapts, by way of I/O device 31, the projection system settings during the processing run in accordance with the imaging correction parameters for abberation induced distortion as given by equations. Again, during the lithographic processing run, the combination of actual imaging correction parameters can be made available from the database through information in the job data file for the processing run to an on-line adaptation procedure. The on-line adaptation procedure adapts the projection system settings during the processing run in accordance with the imaging correction parameters for abberation induced distortion as given by the equations sets. The correction of the aerial image for pattern abberation induced distortion and the on-line adaptation procedure are carried out by the computer arrangement. The computations are performed by the processor, data relating to correction parameters for the projection system being stored in the memory units of the computer arrangement. The processor determines the imaging correction parameters and instructs the I/O device to transmit imaging correction signals to the actuating device AD of the projection system which comprises sensors and actuators for correcting the pattern abberation induced distortion during the processing run. Reference has already been made above to the use of one or more transmission image sensors (TIS) mounted within a physical reference surface associated with the substrate table (WT) which may be used to determine the position of one or more marks on the mask (or reticle), as described in U.S. Pat. No. 4,540,277, in order to adjust the mask alignment (overlay). Advanced process control (APC) systems are commonly used to ensure good overlay. After exposure of a lot, the overlay is measured on a few wafers from the lot using a so-called overlay metrology tool, and the measured overlay metrology data is sent to the APC system. The APC system then calculates overlay corrections, based on exposure and processing history, and these corrections are used to adjust the scanner to minimize the overlay error. This is also known as an overlay metrology feedback loop. However, because of the distortion of the TIS and/or overlay marks due to the lens aberrations remaining after compensation for the specific product application, significant X-Y alignment errors may still exist, and, if adjustments are done to minimize the errors on the TIS and/or overlay marks, these may be inappropriate to optimise the imaging performance during exposure of the product (or conversely to provide accurate alignment in the event that adjustments are done to minimize the product exposure errors). Accordingly the IQEA model may be adapted to determine the appropriate corrections and permitted distortions for the different features (that is the product features, the TIS mask marks, the overlay metrology targets and the wafer alignment marks). Furthermore, since the different features are used at different points in the total lithographic control loop, it is important that the required error correction data is supplied to the right location. In such an arrangement the IQEA model is disposed in a loop with a simulator to calculate the sensitivities of the different features. These sensitivities are input into the combined linearised-IQEA-model/lens model that calculates the optimal lens settings for the product features. These lens settings are then sent to a lens driver for making the necessary lens adjustments. Furthermore, TIS mask (or reticle) mark offsets calculated by this model are sent to a metrology driver that is able to correct for these offsets so that the right mask alignment parameters will be calculated in an unbiased way. The TIS mark offsets are used to correct the measured TIS positions prior to exposure of the wafers in order to ensure that the positions of the product features are correctly represented. The offsets of the exposed overlay metrology targets and the non-zero wafer alignment marks provided by the model, which data needs to be used at a different time and location, are sent to the APC system. The metrology offsets are used to calculate the offset of the overlay metrology feedback and are accordingly supplied to the system that is going to expose the same layer. The wafer alignment mark offsets are supplied to the system that is going to expose the next layer in a feed forward arrangement. In the case of a lens heating situation the data handling becomes more complex since all the corrections and offsets depend on the aberration drift of the system under the influence of the lens heating, and accordingly the shifts of all the different features (that is the product features, the TIS mask marks, overlay metrology targets and wafer alignment marks) due to such lens heating must be taken account of in the calculations. A typical sequence of calculations in this case for determining the X-Y positions of the product and the positions of the TIS, (off-line) overlay metrology and alignment features for each exposed die is as follows: 1. Just before exposure calculate the shifts in the X-Y positions of the TIS marks, the overlay metrology target and the alignment marks with respect to product position 2. Correct the measured TIS mark positions with the calculated offsets prior to exposure of the particular die on the wafer 3. Repeat for other dies and wafers, the lens heating causing the actual aberrations to change and the positions of the TIS marks, the overlay metrology target and the alignment marks to shift with respect to the product position 4. Store the shifts for overlay metrology target positions in the APC-system, so that the APC feedback loop can be optimised for product overlay (the overlay on some wafers being measured). It should be noted that, when the overlay metrology tool measures an overlay, this will always be a difference in the shifts for the two layers, and the shifts for both layers need to be taken account of in determination of the metrology overlay target. For example, in the case of a box-in-box-structure, it will be necessary to take into account a shift for the inner-box (this shift having been determined when exposing this inner-box, because it was exposed with image adjustments optimised for the product) and a different shift for the outer box (this shift also having been determined already) in order to get the best possible estimate of the true overlay. 5. When exposing the next layer on each wafer, correct the measured alignment mark positions with the calculated offsets before the exposure. | <SOH> BACKGROUND OF THE INVENTION <EOH>The invention finds application, for example, in the field of lithographic projection apparatus incorporating a radiation system for supplying a projection beam of radiation, a support structure for supporting a patterning device, which serves to pattern the projection beam according to a desired pattern, a substrate table for holding a substrate; and a projection system for projecting the patterned beam onto a target portion of the substrate. The term “patterning device” as employed here should be broadly interpreted as referring to devices and structures that can be used to endow an incoming radiation beam with a patterned cross-section, corresponding to a pattern that is to be created in a target portion of the substrate; the term “light valve” can also be used in this context. Generally, the pattern will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit or other device (see below). Examples of such patterning devices include: A mask. The concept of a mask is well known in lithography, and it includes mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. Placement of such a mask in the radiation beam causes selective transmission (in the case of a transmission mask) or reflection (in the case of a reflective mask) of the radiation impinging on the mask, according to the pattern on the mask. In the case of a mask, the support structure will generally be a mask table, which ensures that the mask can be held at a desired position in the incoming radiation beam, and that it can be moved relative to the beam if so desired. A programmable mirror array. One example of such a device is a matrix-addressable surface having a visco-elastic control layer and a reflective surface. The basic principle behind such an apparatus is that (for example) addressed areas of the reflective surface reflect incident light as diffracted light, whereas unaddressed areas reflect incident light as non-diffracted light. Using an appropriate filter, the non-diffracted light can be filtered out of the reflected beam, leaving only the diffracted light behind; in this manner, the beam becomes patterned according to the addressing pattern of the matrix-addressable surface. An alternative embodiment of a programmable mirror array employs a matrix arrangement of tiny mirrors, each of which can be individually tilted about an axis by applying a suitable localized electric field, or by employing one or more piezoelectric actuators. Once again, the mirrors are matrix-addressable, such that addressed mirrors will reflect an incoming radiation beam in a different direction to unaddressed mirrors; in this manner, the reflected beam is patterned according to the addressing pattern of the matrix-addressable mirrors. The required matrix addressing can be performed using suitable electronic circuitry. In both of the situations described here above, the patterning device can comprise one or more programmable mirror arrays. More information on mirror arrays as here referred to can be gleaned, for example, from U.S. Pat. No. 5,296,891 and U.S. Pat. No. 5,523,193, and from WO 98/38597 and WO 98/33096, which are incorporated herein by reference. In the case of a programmable mirror array, the support structure may be embodied as a frame or table; for example, which may be fixed or movable as required. A programmable LCD array. An example of such a construction is given in U.S. Pat. No. 5,229,872, which is incorporated herein by reference. As above, the support structure in this case may be embodied as a frame or table, for example, which may be fixed or movable as required. For simplicity, parts of the rest of this specification are directed specifically to examples involving a mask and mask table; however, the general principles discussed in such instances should be seen in the broader context of the patterning device as set forth above. Lithographic projection apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, the patterning device may generate a circuit pattern corresponding to an individual layer of the IC, and this pattern can be imaged onto a target portion (e.g. comprising one or more dies) on a substrate (silicon wafer) that has been coated with a layer of radiation-sensitive material (resist). In general, a single wafer will contain a whole network of adjacent target portions that are successively irradiated via the projection system, one at a time. In current apparatus, employing patterning by a mask on a mask table, a distinction can be made between two different types of machine. In one type of lithographic projection apparatus, each target portion is irradiated by exposing the entire mask pattern onto the target portion in one go; such an apparatus is commonly referred to as a wafer stepper or step-and-repeat apparatus. In an alternative apparatus, commonly referred to as a step-and-scan apparatus, each target portion is irradiated by progressively scanning the mask pattern under the projection beam in a given reference direction (the “scanning” direction) while synchronously scanning the substrate table parallel or anti-parallel to this direction; since, in general, the projection system will have a magnification factor M (generally <1), the speed V at which the substrate table is scanned will be a factor M times that at which the mask table is scanned. More information on such lithographic devices is disclosed in U.S. Pat. No. 6,046,792, the contents of which are incorporated herein by reference. In a manufacturing process using a lithographic projection apparatus, a pattern (e.g. in a mask) is imaged onto a substrate that is at least partially covered by a layer of radiation-sensitive material (resist). Prior to this imaging step, the substrate may undergo various procedures, such as priming, resist coating and a soft bake. After exposure, the substrate may be subjected to other procedures, such as a post-exposure bake (PEB), development, a hard bake and measurement/inspection of the imaged features. This combination of processing steps is used as a basis for patterning of a single layer of the device which is for example an integrated circuit (IC). Such a patterned layer may then undergo various processes, such as etching, ion-implantation (doping), metallization, oxidation, chemical-mechanical polishing, etc., all of which are intended to finish off an individual layer. If several layers are required, then the whole procedure, or a variant thereof, will have to be repeated for each new layer. Eventually, an array of devices will be produced on the substrate (wafer). These devices are then separated from one another by a technique such as dicing or sawing, so that the individual devices can be mounted on a carrier, connected to pins, etc. Further information regarding such processing can be obtained, for example, from “Microchip Fabrication: A Practical Guide to Semiconductor Processing”, Third Edition, by Peter van Zant, McGraw Hill Publishing Co., 1997, ISBN 0-07-0672504, incorporated herein by reference. For simplicity, the projection system may hereinafter be referred to as the “lens”. However, this term should be broadly interpreted as encompassing various types of projection system, including refractive optics, reflective optics, and catadioptric systems, for example. The radiation system may also include components operating according to any of these design types for directing, shaping or controlling the projection beam of radiation, and such components may also be referred to below, collectively or singularly, as a “lens”. Furthermore, the lithographic apparatus may be of a type having two or more substrate tables (and/or two or more mask tables). In such “multiple stage” devices the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposures. Dual stage lithographic apparatus is described, for example, in U.S. Pat. No. 5,969,441 and WO 98/40791, the contents of both of which are incorporated herein by reference. Although specific reference may be made in this specification to the use of the apparatus according to the invention in the manufacture of integrated circuits, it should be explicitly understood that such an apparatus has many other possible applications. For example, it may be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, liquid-crystal display panels, thin-film magnetic heads, etc. The person skilled in the art will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” in this text should be considered as being replaced by the more general terms “substrate” and “target portion”, respectively. Generally, throughout the specification, any use of the term “mask” should be considered as encompassing within its scope the use of the term “reticle” In the present document, the terms “radiation” and “projection beam” are used to encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g. with a wavelength of 365, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range 5-20 nm). The phenomenon of lens heating can occur in the projection system of a lithographic projection apparatus. The projection lens becomes slightly heated by the projection beam radiation during exposures. As a result of this heating, refractive index changes occur, and a certain expansion of lens elements occurs, causing subtle changes in the geometric form of those elements, with an attendant change in their optical properties. This can result in the occurrence of new lens aberrations, or a change in existing aberrations. Because the occurrence of these aberration changes depends on such matters as the particular lens geometry, lens material, projection wavelength, light source power, target portion, wafer-reflectivity, size, and so on, the accuracy with which the effects of such lens heating can be predicted can be limited, especially in the absence of any measurement and compensating mechanism. Lens heating has always occurred to some extent in lithographic projection apparatus. However, with the trend to integrating an ever-increasing number of electronic components, and thus smaller features, in an IC, and to increase the manufacturing throughput, shorter wavelength radiation, such as EUV radiation has been used, as well as high-power radiation sources, such as 3-6 kW Mercury-arc lamps and excimer lasers with a power of 10 to 20 W, which together with the reduction in feature size have made lens heating a more serious problem. The problem is generally worse in scanners than in steppers because, in a stepper, substantially the whole (circular) cross-section of each lens element is irradiated, whereas, in a scanner, generally only a slit-shaped portion of the lens elements is irradiated; consequently, the effect in a scanner is far more differential than in a stepper, even if the lens aberrations in the scan direction are averaged out in the scanner, thereby resulting in the occurrence of new lens aberrations. The change in the optical properties of the elements of the projection system due to such lens heating naturally affects the image that is projected, principally by causing a change in the image parameters, of which magnification is particularly important for the XY-plane, and focus is particularly important for the Z-plane. However this lens heating effect can be calibrated and compensated for very well, e.g. by adjusting the positions of the lens elements to effect a compensating change in magnification or other image parameters of the projection system, for example as disclosed in EP 1164436A or U.S. Pat. No. 6,563,564, the contents of both of which are incorporated herein by reference. The lens heating effects depend on the lens properties, which are calibrated when the apparatus is constructed and may be recalibrated periodically thereafter, and various parameters of the exposures carried out, such as mask transmission, dose, illumination settings, field size and substrate reflectivity. When performing imaging in a lithographic projection apparatus, despite the great care with which the projection system is designed and the very high accuracy with which the system is manufactured and controlled during operation, the image can still be subject to aberrations, which can cause offsets in the image parameters for example, distortion (i.e. a non-uniform image displacement in the target portion at the image plane: the XY-plane), lateral image shift (i.e. a uniform image displacement in the target portion at the image plane), image rotation, and focal plane deformation (i.e. a non-uniform image displacement in the Z-direction, for instance, field curvature). It should be noted that, in general, image parameter offsets are not necessarily uniform, and can vary as a function of position in the image field. Distortion and focal plane deformation can lead to overlay and focus errors, for example overlay errors between different mask structures, and line-width errors. As the size of features to be imaged decreases, these errors can become intolerable. Consequently, it is desirable to provide compensation (such as adjustment of the projection system and/or substrate) to correct for, or at least attempt to minimize, these errors. This presents the problems of first measuring the errors and then calculating appropriate compensation. Previously, alignment systems were used to measure the displacements in the image field of alignment marks. However, alignment marks typically consist of relatively large features (of the order of a few microns), causing them to be very sensitive to specific aberrations of the projection system. The alignment marks are unrepresentative of the actual features being imaged, and because the imaging errors depend inter alia on feature size, the displacements measured and compensations calculated did not necessarily optimize the image for the desired features. Another problem occurs when, for instance, because of residual manufacturing errors, the projection system features an asymmetric variation of aberration over the field. These variations may be such that at the edge of the field the aberration becomes intolerable. A further problem occurs when using phase-shift masks (PSM's). Conventionally, the phase shift in such masks has to be precisely 180 degrees. The control of the phase is critical; deviation from 180 degrees is detrimental. PSM's, which are expensive to make, must be carefully inspected, and any masks with substantial deviation in phase shift from 180 degrees will generally be rejected. This leads to increased mask prices. A further problem occurs with the increasing requirements imposed on the control of critical dimension (CD). The critical dimension is the smallest width of a line or the smallest space between two lines permitted in the fabrication of a device. In particular the control of the uniformity of CD, the so-called CD uniformity, is of importance. In lithography, efforts to achieve better line width control and CD uniformity have recently led to the definition and study of particular error types occurring in features, as obtained upon exposure and processing. For instance, such image error types are an asymmetric distribution of CD over a target portion, an asymmetry of CD with respect to defocus (which results in a tilt of Bossung curves), asymmetries of CD within a feature comprising a plurality of bars (commonly referred to as Left-Right asymmetry), asymmetries of CD within a feature comprising either two or five bars (commonly known as L1-L2 and L1-L5, respectively), differences of CD between patterns that are substantially directed along two mutually orthogonal directions (for instance the so-called H-V lithographic error), and for instance a variation of CD within a feature, along a bar, commonly known as C-D. Just as the aberrations mentioned above, these errors are generally non-uniform over the field. For simplicity we will hereafter refer to any of these error types, including the errors such as, for example, distortion, lateral image shift, image rotation, and focal plane deformation, as lithographic errors, i.e. feature-deficiencies of relevance for the lithographer. Lithographic errors are caused by specific properties of the lithographic projection apparatus. For instance, the aberration of the projection system, or imperfections of the patterning devices and imperfections of patterns generated by the patterning devices, or imperfections of the projection beam may cause lithographic errors. However, also nominal properties (i.e. properties as designed) of the lithographic projection apparatus may cause unwanted lithographic errors. For instance, residual lens aberrations which are part of the nominal design may cause lithographic errors. For reference hereafter, we will refer to any such properties that may cause lithographic errors as “properties”. As mentioned above, the image of a pattern can be subject to aberrations of the projection system. A resulting variation of CD (for example, within a target portion) can be measured and subsequently be mapped to an effective aberration condition of the projection system which could produce said measured CD variation. A compensation can then be provided to the lithographic projection system such as to improve CD uniformity. Such a CD-control method is described in U.S. Pat. No. 6,115,108, incorporated herein by reference, and comprises imaging a plurality of test patterns at each field point of a plurality of field points, a subsequent processing of the exposed substrate, and a subsequent CD measurement for each of the imaged and processed test patterns. Consequently, the method is time consuming and not suitable for in-situ CD control. With increasing demands on throughput (i.e. the number of substrates that can be processed in a unit of time) as well as CD uniformity, the control, compensation and balancing of lithographic errors must be improved, and hence, there is the problem of furthering appropriate control of properties. U.S. Pat. No. 6,563,564 (P-0190) discloses a lens heating model by which projection system aberrations due to the lens heating effect can be corrected for by way of image parameter offset control signals that serve to adjust the image parameters of the projection system to compensate for the calculated change in the aberration effect due to such lens heating. In this case the change in the aberration effect with time is determined on the basis of a stored set of predetermined parameters corresponding to the selected aberration effect, these parameters can be obtained by a calibration step. The image parameter offsets may comprise focus drift, field curvature, magnification drift, third-order distortion, and combinations thereof. However, the required ideal compensation will depend on the particular application (the particular pattern, illumination mode, etc.), and the number of parameters that can be adjusted is generally not high enough to cancel out every aberration completely, so that the determination of the compensation to apply in a particular case will always be a compromise, the particular compromise to be chosen depending on the required application. Because the conventional lens heating model does not take into account the particular application, it follows that the calculated compensation will not be optimal for every particular application. EP 1251402A1 (P-0244) discloses an arrangement for compensating for projection system aberrations on the basis of the relationship between properties of the substrate, the layer of radiation sensitive material on the substrate, projection beam, the patterning device and the projection system, and the lithographic errors causing anomalies in the projected image. A control system determines a merit function which weighs and sums the lithographic errors, and calculates a compensation to apply to at least one of the substrate, the projection beam, the patterning device and the projection system to optimize the merit function. Although the use of such a merit function enables compensation to be applied in such a manner as to reach a reasonable compromise in terms of optimization of the image, it is found that, since such optimization is intended to provide the best compromise in terms of imaging quality over the whole of the image, the image quality in parts of the image or in particular applications may be relatively low. A control system may be provided for compensating for the effect of changes in a property of lithographic projection apparatus with time, such as the change in magnification of the projection system due to lens heating, in which a control signal is generated according to a predicted change in the property with time, a comparator compares a value based on the predicted change to a threshold, and generates a trigger signal when the value is greater than the threshold value, and the alignment system performs an alignment in response to the trigger signal. Such an arrangement triggers a so-called “realignment” when the predictive correction becomes larger than the desired maximum. This system therefore predicts the heating effects that will occur in performing a series of exposures and applies appropriate corrections in advance of the exposures being made when the corresponding threshold value is exceeded. This technique ensures that realignments occur only when errors are out of certain ranges, and avoids unnecessary realignments, thus avoiding loss of throughput in the exposure process. In certain applications errors in the predictive correction may result in unnecessary additional alignment steps and loss of throughput, since the optimal time for realignment is not calculated on the basis of the particular application. This could mean in practice that the imaging performance is worse than expected in a particular series of exposures, due to the realignment being triggered too late for the particular application; or the throughput is less than expected, due to the realignment being effected sooner than required in the series of exposures. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to effect adjustments to the projection system of lithographic projection apparatus to compensate for the effect of lens aberrations in such a manner as to provide optimal image quality for a particular application, that is for a particular combination of mask (for example the product pattern) and illumination mode. According to the present invention there is provided lithographic projection apparatus including a radiation system for providing a beam of radiation, a support structure for supporting a patterning device for imparting a pattern to the projection beam, a substrate table for holding a substrate, a projection system for projecting the patterned beam onto a target portion of the substrate so as to produce an image of the patterning device on the target portion, a predictive system for predicting changes in projection system aberrations with time with respect to measured aberration values, a modelling system for determining the application-specific effect of said predicted projection system aberration changes on certain parameters of the image of a selected patterning device to be used in the apparatus for producing a specific required patterned beam, a control system for generating a control signal specific to the required patterned beam according to said predicted projection system aberration changes and their application-specific effect on certain parameters of the image, and an adjustment system for carrying out imaging adjustments in dependence on the control signal to compensate for the application-specific effect of said predicted projection system aberration changes on the image of the selected patterning device. In this specification the term “application” is used to denote the combination of the patterning device (the mask) and the illumination mode. In this regard the patterning device may be a conventional mask or reticle or a phase shift mask (PSM) and may be characterized by the feature size, the orientation, the density, etc. of the pattern to be produced on the product by the patterning device), and the illumination mode may be characterized by the numerical aperture (NA), the sigma inner/outer, the diffractive optical elements (DOE's), etc. This enables the aberrations to be compensated for, with precedence being given to those aberrations that are of most significance to the particular application (the particular pattern, illumination mode, etc.) in preference to aberrations that are of lesser significance in relation to that particular application. The appropriate adjustments to compensate for the aberrations that are appropriate to the particular application can then be determined and applied in such a manner to cancel out the effect of the aberrations optimally for the given application. For example, when the product pattern or part of the product pattern to be lithographically exposed has only horizontal lines as the features that require to be accurately defined by the lithographic exposure, such an arrangement will ensure that the effect of the aberrations of the projection system will be cancelled out optimally only for such horizontal lines and not for vertical lines. The fact that, in this example, the effect of the aberrations so far as hypothetical vertical lines are concerned is not compensated for optimally is immaterial since no such vertical lines require to be defined accurately in the product or the relevant part of the product. The adjustment system can be constituted by any suitable compensation scheme for compensating for the effect of the aberration changes. Methods of compensating for aberrations suitable for use with lithographic projection apparatus are, for instance, adjustments to fine position (an X-, Y-, and Z- translation, and a rotation about the X-, Y-, and Z-axis) of the holder for holding the patterning device, similar fine positioning of the substrate table, movements or deformation of optical elements (in particular, fine positioning using an X-, Y-, and Z- translation/rotation of optical elements of the projection system), and, for instance, methods and devices that change the energy of the radiation impinging on the target portion. However, suitable compensations are not limited to such examples; for instance, methods of changing the wavelength of the radiation beam, changes to the imaged pattern, changing the index of refraction of gas-filled spaces traversed by the projection beam, and changing the spatial distribution of the intensity of the radiation beam may also serve to effect the required compensation. The adjustment system may be adapted to adjust at least a selected one of: the position of the support structure along the optical axis of the projection system, the rotational orientation of the support structure, the position of the substrate table along said optical axis, the rotational orientation of the substrate table, the position along said optical axis of one or more movable lens elements comprised in said projection system, the degree of decentering with respect to said optical axis of one or more movable lens elements comprised in said projection system, the central wavelength of the projection beam, or saddle-like deformation of one or more lens elements comprised in said projection system using edge actuators. In one implementation of the invention the predictive system is arranged to determine the predicted projection system aberration changes with time on the basis of a lens heating model that predicts changes in at least one aberration value with time as a result of lens heating or cooling. Using an appropriate lens heating model it is possible for appropriate aberration offsets to be predicted in advance so that these aberration offsets can be used to determine the offsets in image parameters which can be used to calculate and thus apply appropriate (optimized with respect to a defined merit function) adjustments for the given application. In another implementation of the invention the modelling system is arranged to determine the application-specific effect of said projection system aberration changes on the basis of data indicative of the selected patterning device and the illumination mode of the projection system. The control system may use information on the aberrations of the projection system to adapt the settings of the projection system in such a way that certain distortions of the image are counteracted optimally. Both low-order aberrations, which cause image distortion effects that are independent of the optical path in the lens system to form the image, and high-order lens aberrations, which relate to distortion effects that depend on the optical path actually used in the lens system, can be corrected by such an arrangement. The control system may be arranged to generate a control signal which preferentially compensates predicted changes in features of the image in one direction in the plane of the image as compared with predicted changes in features of the image in another direction in the plane of the image, in accordance with the known sensitivities of the selected patterning device to projection system aberrations in the two directions. Furthermore the control system may be arranged to generate a control signal which preferentially compensates predicted changes in features of the image in the direction normal to the plane of the image, in accordance with the known sensitivities of the selected patterning device to projection system aberrations in said direction. The control signal can be generated in accordance with a defined merit function determining the relative weightings to be given to the effects of projection system aberrations on different parameters of the image, and in a particular embodiment, in accordance with a user-defined specification. The control system may be arranged to generate a control signal on the basis of known correspondence between changes in imaging adjustments of the adjustment system and the aberration changes being compensated for by such imaging adjustments. Additionally the control system may be arranged to generate a trigger signal to trigger measurement by a measurement system and adjustment by the adjustment system in response to such measurement when the predicted change in the image parameters with time is greater than a threshold value. One embodiment of the invention further includes overlay metrology feedback device for correcting for a shift in a metrology overlay target for a current layer measured with respect to the metrology overlay target for a previous layer, as a result of said predicted projection system aberration changes and the imaging adjustments effected to compensate for the application-specific effect of said predicted projection system aberration changes with respect to measured aberration values on certain parameters of the image, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. Another embodiment of the invention further includes a wafer alignment system for compensating for the effect of a shift in a respective wafer alignment mark provided for the alignment of each layer of successive layers of images to be applied to the target portion, as a result of said predicted projection system aberration changes and the imaging adjustments effected to compensate for the application-specific effect of said predicted projection system aberration changes with respect to measured aberration values on certain parameters of the image, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. Another embodiment of the invention further includes a mask alignment system for compensating for the effect of a shift in an image of a mask alignment mark provided for the alignment of the patterning device relative to the target portion, as a result of said predicted projection system aberration changes and the imaging adjustments effected to compensate for the application-specific effect of said predicted projection system aberration changes with respect to measured aberration values on certain parameters of the image, on the basis of an optimisation procedure providing for the changes in the aberrations to which the image is most sensitive to be compensated for according to a defined merit-function. In one embodiment, the control system incorporates a realignment controller for re-measuring at least one aberration value when the predicted effect on one or more image parameters with time is greater than a corresponding (e.g. user-defined) threshold value. The use of thresholds for the lithographic parameters means that appropriate realignments are made only when these thresholds are exceeded, so that the effect on throughput is minimised whilst still keeping good imaging performance. In a development of the invention the adjustment system is arranged to carry out imaging adjustments over successive scan positions during scanning exposure of the substrate to allow for variations in the scanned image over the extent of the substrate in order to optimise the image as a function of scan position. This enables the optimal projection system adjustments to be varied as a function of the scan position (e.g. the Y-position of the scanner) during an exposure scan so as to enable the image quality to be optimised over the whole of the scan to compensate for variations in the image structure (for example horizontal lines in a first part of the product scanned and vertical lines in a subsequent part of the product scanned) in the scan direction. The invention further provides a device manufacturing method using lithographic projection apparatus, the method including providing a substrate having a target portion for receiving an image, selecting a patterning device in accordance with a required patterning application, using a projection system to project a selected beam of radiation onto the patterning device to produce a specific required patterned beam providing an image of the patterning device on the target portion, predicting changes in projection system aberrations with time with respect to measured aberration values, determining the application-specific effect of said predicted projection system aberration changes on certain parameters of the image of the selected patterning device to be used in the apparatus for producing the specific required patterned beam, generating a control signal specific to the required patterned beam according to said predicted projection system aberration changes and their application-specific effect on certain parameters of the image, and carrying out imaging adjustments in dependence on the control signal to compensate for the application-specific effect of said predicted changes in the aberrations on the image of the selected patterning device. Another aspect of an embodiment of the invention provides a data carrier incorporating a computer program for controlling a device manufacturing method using lithographic projection apparatus, the apparatus including a radiation system for providing a projection beam of radiation, a support structure for supporting patterning device for imparting a pattern to the projection beam, a substrate table for holding a substrate, and an adjustable projection system for projecting the patterned beam onto a target portion of the substrate so as to produce an image of the patterning device on the target portion, the computer program being arranged to effect a method including predicting changes in projection system aberrations with time with respect to measured aberration values, determining the application-specific effect of said predicted projection system aberration changes on certain parameters of the image of the selected patterning device to be used in the apparatus for producing the specific required patterned beam, generating a control signal specific to the required patterned beam according to said predicted projection system aberration changes and their application-specific effect on certain parameters of the image; and carrying out imaging adjustments in dependence on the control signal to compensate for the application-specific effect of said predicted changes in the aberrations on the image of the selected patterning device. | 20040708 | 20080722 | 20060112 | 84346.0 | G03C500 | 1 | NGUYEN, HUNG | LITHOGRAPHIC PROJECTION APPARATUS AND A DEVICE MANUFACTURING METHOD USING SUCH LITHOGRAPHIC PROJECTION APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | G03C | 2,004 |
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10,886,090 | ACCEPTED | Razor for buzz cutting head hair | A dual wet razor device is used for shaving hair on a head at different lengths. The device has a first and a second cutting edge on opposite sides of one another and a sensitive guide under each cutting edge for safely cutting different short lengths of hair on the scalp of a user. | 1. A dual wet razor device for shaving hair on a head at different lengths comprising a handle having a razor head disposed at one end, said head adapted to hold a razor for cutting hair, said razor providing a first cutting edge and a second cutting edge disposed on the opposite sides of said head, a sensitive guide attached to said razor head extending outwardly from each of said first and second cutting edge, each said sensitive guide is sized for disposing said first and second cutting edges at different predetermined distances from said head scalp whereby the first and second cutting edges are adapted for selectively wet shaving the hair on the head at different lengths. 2. The dual wet razor of claim 1 wherein a razor blade provides said first and second cutting edges. 3. The dual wet razor of claim 2 wherein the razor blade is removably attached to the razor head. 4. The dual wet razor of claim 1 wherein each sensitive guide comprises a plurality of rounded knobs on said head to facilitate movement of the razor across the scalp for safely cutting the hair. 5. The dual wet razor of claim 1 wherein said handle is elongated for gripping by the user's hand and the razor head is disposed at one end of the handle such that rotation of said handle enables the user to cut hair with either of said first or second cutting edges. 6. The dual wet razor of claim 1 wherein each sensitive guide extends outwardly from and above each cutting edge to dispose each cutting edge at an angle to the scalp for cutting the hair. 7. A dual wet razor device for shaving hair on a head at different lengths comprising a handle having a razor head disposed at one end, said head adapted to hold a razor blade edge on opposite sides of said head, a sensitive guide attached to said razor head extending outwardly on opposite sides of said head from said razor blade edge to form first and second cutting edges, said sensitive guide comprises a plurality of knobs which are sized for disposing said first and second cutting edges at different predetermined distances from said head scalp whereby the first and second cutting edges are adapted for selectively wet shaving the hair on the head at different lengths. 8. The dual wet razor of claim 7 wherein each sensitive guide comprises a plurality of rounded knobs on said head to facilitate movement of the razor across the scalp for safely cutting the hair at the predetermined length. 9. The dual wet razor of claim 7 wherein said handle is elongated for gripping by the user's hand and the razor head is disposed at one end of the handle such that rotation of said handle enables the user to cut hair with either of said first or second cutting edges. 10. The dual wet razor of claim 7 wherein each sensitive guide extends outwardly from and above each cutting edge to dispose each cutting edge at an angle to the scalp for cutting the hair | FIELD OF THE INVENTION This invention relates to a head shaving razor and, in particular, to a razor designed for wet shaving of hair close to the scalp thereby leaving a predetermined length of hair on ones head. BACKGROUND OF THE INVENTION It has been common practice to trim hair on the scalp and obtain what has been commonly referred to as a “buzz cut” with an electric clipper. The buzz cut refers to very short or stubbled hair length on the head. Different attachments have been employed with the electric clipper in order to leave a short length of hair at a predetermined distance from the scalp. More recently, individuals are interested in conveniently shaving their own head in order to obtain the clean head-shaved hair appearance rather than going to a salon or barber shop. Individuals thereby save money and are able to always appear well groomed with a length of hair which they may desire. Thus, there has been a need for some simple and relatively inexpensive razor for enabling an individual to easily and safely wet shave his own head hair. Such a device is especially desired for safely wet shaving head hair while showering. It would also be advantageous to have a wet shave razor which is versatile for hair cutting at different lengths. SUMMARY OF THE INVENTION This invention is directed to a razor which enables an individual to wet shave his own head at a predetermined length of hair. This invention provides a razor which is versatile in facilitating shaving of head hair to obtain a buzz cut of different lengths with one razor device. The dual wet razor device is especially designed for an individual to safely shave the hair on his head very close to the scalp. The razor can be used in the shower by applying shaving gel and shaving the head thereby enabling an individual to cut his own hair and keep the haircut well groomed at all times. The dual wet razor device of this invention has a handle and a shaving head disposed at the end of the handle. The shaving head is adapted to hold a razor blade having a first and a second cutting edge which are disposed opposite one another. Each cutting edge is protected by a sensitive guide which separates the cutting edge from scalp and determines the cut length of hair. The first razor cutting edge is disposed by the guide at a distance of, for example, ⅛ of an inch to provide a cut length of hair. The second cutting edge is spaced from the guide at a greater distance, for example, to provide a ¼ inch haircut. Accordingly, the differently spaced cutting edges enable the dual versatile razor for shaving the hair on the scalp at two distinct lengths depending upon the desire of the user. The sensitive guides are mounted on the razor head and positioned outwardly from the blade to determine the length of the hair exposed to each cutting edge of the razor blade so as to leave hair on the scalp at a predetermined distance. In a preferred form, the sensitive guide is formed by a plurality of rounded knobs which cooperate with the cutting blade so as to provide a smooth, clean and safe haircut. Thus, the dual razor avoids cutting abnormalities on the scalp, such as moles, scars or folds in the skin, and the like. These rounded guides will also raise the hair just by their movement on the scalp and will feed the hair to the blade for cutting. Other forms of guides may be used to provide the same results. These and other objectives of this invention are accomplished by a razor device having a single head and a razor blade having two opposite cutting edges mounted on one end of a single handle. The razor head is provided with sensitive guides disposed adjacent to and outwardly from each cutting edge such that the cutting edges face in opposite directions for cutting different lengths of hair on the scalp. The user thus employs a single razor having one cutting blade and two different cutting edges which the user may select for obtaining different hair lengths of a buzz cut on his scalp by simply rotating the handle of the razor. The benefits and advantages of this invention will be further understood with reference to the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a razor device according to the invention. FIG. 2 is a cross sectional view of the razor device taken along line 2-2 of FIG. 1 illustrating the razor head, blade cutting edge and guides which illustrates sensitive guides of different lengths on opposite sides of the razor head adjacent to each cutting edge. FIG. 3 is a cross sectional view of the razor device according to the invention, similar to the view of FIG. 2, showing the razor device in use. DETAILED DESCRIPTION AND PREFERRED EMBODIMENT A wet buzz cut razor device 10 of the invention as shown in FIGS. 1-3 has an elongated handle 11 and a razor head 12 attached to the handle at one end. The razor head 12 is adapted to hold one or more razor blades 13 to form a first cutting edge 14 and a second cutting edge 15 which are on opposite sides of the head 12. The first and second cutting edges 14, 15 are positioned such that the razor head 12 may simply be rotated 180° to provide a razor head having the ability to shave hair at different lengths on the scalp. The razor head 12 also supports sensitive guides 16, 17 which extend outwardly from each cutting edge of the razor blade 13. As shown, the sensitive guides 16, 17 are of different sizes so as to dispose each cutting edge 14, 15 at a predetermined distance from the scalp for cutting the hair at different lengths. In a preferred form, the sensitive guides 16, 17 are designed such that no sharp edges are presented to the scalp such as those shown as knobs having a rounded shape. In a preferred form, a plurality of sensitive guides 16, 17 are employed on each opposite side of the razor head 12. At least one knob is on each end of a cutting edge and one is in the center. In the most preferred form, the guides 16, 17 extend outwardly from and above the cutting blade edge 14, 15 so that the blade is disposed at an angle to the scalp for efficiently cutting the hair as shown in FIG. 3. For example, the sensitive guides 16, 17 are disposed at distances for leaving ⅛ inch long hair (guides 17) on the scalp or ¼ inch long hair (guides 16) on the scalp. The sensitive guides 16, 17 tend to raise the hair just by movement on the scalp and will feed the hair to the blade 13 for cutting. The dual razor device of FIGS. 1-3 according to the invention is used in a conventional manner. Usually the hair has been cut short and the person wishes to return it to a buzz cut length. For instance, the razor may be used in the shower by applying a shaving gel to the scalp and the head may be shaved by cutting to the desired length with the single razor head. After applying a shaving gel, the user simply elects either the long or short hair cutting edge in order to shave the hair. This may be achieved by simply employing the short or long hair cutting edge by rotating the handle of the razor device. Accordingly, the short cutting edge can be applied for precise shaving of the hair stubble close to the scalp. Alternatively, the user can select either cutting edge by simple rotation of the handle to achieve different lengths of hair remaining on the scalp in different areas, depending upon the desire of the user. The dual razor device may be designed for disposable use by fabrication with a plastic material, as razor heads are known in the art, in an inexpensive manner so that the razor may discarded. On the other hand, the razor device may be fabricated with a permanent handle and head such that the blade is removable so that it may be discarded and replaced when the blade becomes dull. Of course, more than one blade may be mounted on the razor head on opposite sides of the head to achieve the objectives of this invention and thereby replacing a single blade having different cutting edges. It is preferred for cost savings to employ one blade having a cutting edge on each side. Those in the art should appreciate that the razor device of the present invention is not limited to the particular construction disclosed and are shown in the drawings. Instead, the present invention also encompasses any modifications or equivalents that would be understood to a person of skill in the art to achieve the objectives of this invention in view of the above description. | <SOH> BACKGROUND OF THE INVENTION <EOH>It has been common practice to trim hair on the scalp and obtain what has been commonly referred to as a “buzz cut” with an electric clipper. The buzz cut refers to very short or stubbled hair length on the head. Different attachments have been employed with the electric clipper in order to leave a short length of hair at a predetermined distance from the scalp. More recently, individuals are interested in conveniently shaving their own head in order to obtain the clean head-shaved hair appearance rather than going to a salon or barber shop. Individuals thereby save money and are able to always appear well groomed with a length of hair which they may desire. Thus, there has been a need for some simple and relatively inexpensive razor for enabling an individual to easily and safely wet shave his own head hair. Such a device is especially desired for safely wet shaving head hair while showering. It would also be advantageous to have a wet shave razor which is versatile for hair cutting at different lengths. | <SOH> SUMMARY OF THE INVENTION <EOH>This invention is directed to a razor which enables an individual to wet shave his own head at a predetermined length of hair. This invention provides a razor which is versatile in facilitating shaving of head hair to obtain a buzz cut of different lengths with one razor device. The dual wet razor device is especially designed for an individual to safely shave the hair on his head very close to the scalp. The razor can be used in the shower by applying shaving gel and shaving the head thereby enabling an individual to cut his own hair and keep the haircut well groomed at all times. The dual wet razor device of this invention has a handle and a shaving head disposed at the end of the handle. The shaving head is adapted to hold a razor blade having a first and a second cutting edge which are disposed opposite one another. Each cutting edge is protected by a sensitive guide which separates the cutting edge from scalp and determines the cut length of hair. The first razor cutting edge is disposed by the guide at a distance of, for example, ⅛ of an inch to provide a cut length of hair. The second cutting edge is spaced from the guide at a greater distance, for example, to provide a ¼ inch haircut. Accordingly, the differently spaced cutting edges enable the dual versatile razor for shaving the hair on the scalp at two distinct lengths depending upon the desire of the user. The sensitive guides are mounted on the razor head and positioned outwardly from the blade to determine the length of the hair exposed to each cutting edge of the razor blade so as to leave hair on the scalp at a predetermined distance. In a preferred form, the sensitive guide is formed by a plurality of rounded knobs which cooperate with the cutting blade so as to provide a smooth, clean and safe haircut. Thus, the dual razor avoids cutting abnormalities on the scalp, such as moles, scars or folds in the skin, and the like. These rounded guides will also raise the hair just by their movement on the scalp and will feed the hair to the blade for cutting. Other forms of guides may be used to provide the same results. These and other objectives of this invention are accomplished by a razor device having a single head and a razor blade having two opposite cutting edges mounted on one end of a single handle. The razor head is provided with sensitive guides disposed adjacent to and outwardly from each cutting edge such that the cutting edges face in opposite directions for cutting different lengths of hair on the scalp. The user thus employs a single razor having one cutting blade and two different cutting edges which the user may select for obtaining different hair lengths of a buzz cut on his scalp by simply rotating the handle of the razor. The benefits and advantages of this invention will be further understood with reference to the drawings and detailed description. | 20040707 | 20080129 | 20060112 | 70277.0 | B26B2100 | 0 | PAYER, HWEI-SIU C | RAZOR FOR BUZZ CUTTING HEAD HAIR | SMALL | 0 | ACCEPTED | B26B | 2,004 |
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10,886,100 | ACCEPTED | Astronomical timepiece | The present invention concerns an electronic astronomical watch, in particular of the wristwatch type, said watch (1) being capable of indicating the position of celestial bodies in the heavens, said watch (1) including: a time base (48) for producing a standard frequency signal; means (50) for determining the current time and date from the standard signal means (28, 30) for selecting a celestial body; analogue time display means using two hands (10, 12); means (32) for determining the position of the selected celestial body in the heavens and indicating this position via the display means (10, 12), the watch (1) being wherein it includes a rotating dial (14) on which there is shown the map (16) of the heavens and in that the shape of the hands (10, 12) is such that their intersection or point of conjunction enables any point of the map of the heavens (16) to be designated on the dial (14). | 1. An electronic astronomical watch, in particular of the wristwatch type, said watch being capable of indicating the position of celestial bodies in the heavens, said watch including: a time base for producing a standard frequency signal; means for determining the current time and date from the standard signal; means for selecting a celestial body; analogue time display means using two hands; means for determining the position of the selected celestial body in the heavens and indicating this position via the display means, the watch being wherein it includes a rotating dial on which there is shown the map of the heavens and wherein the shape of the hands is such that their intersection or point of conjunction enables any point of the map of the heavens to be designated on the dial. 2. The watch according to claim 1, wherein the map of the heavens is a diagram of the stars and constellations, particular the zodiac constellations, visible from the earth. 3. The watch according to claim 1, wherein it enables the position of the planets of the solar system to be identified. 4. The watch according to claim 1, wherein it includes a glass onto which a horizon line is added, which indicates to a user at any time, which of the constellations are visible from the place where he is located. 5. The watch according to claim 1, wherein the rotating dial completes one revolution in 23 hours 56 minutes and 4.09 seconds. 6. The watch according to claim 1, wherein it includes a rotating control stem, which can be moved between three positions, namely a stable neutral position which corresponds to the normal operation of the watch, a pulled out position that is also stable and an unstable pushed in position in which a return spring permanently tends to return the stem to the neutral position. 7. The watch according to claims 1, wherein it includes a rotating bezel, which carries the symbols of the celestial bodies and whose position can be identified by means of magnets included in the bezel and REED contacts placed inside the watch. 8. Watch according to claim 7, wherein a fixed scale carried by a flange is arranged concentrically between the rotating dial and the rotating bezel. 9. Watch according to claim 1, wherein that the map of the heavens is established for a latitude of 45° North. 10. Watch according to claim 1, wherein the means for determining the position of the celestial bodies and indicating this position via the display means include a control unit, associated with a memory in which there are stored the parameters concerning the constellations and relative movements of the celestial bodies with respect to the earth, needed by the control unit for calculating the position of a celestial body at a given date. 11. Watch according to claim 1, wherein the time base is formed by a quartz oscillator including a quartz resonator and an electronic maintenance circuit, which enables the resonator to vibrate at a determined frequency. 12. Watch according to claim 1, wherein the circuit for determining the current time and date includes a frequency divider as well as counters for the minutes, hours, days of the month, months and years. | This application claims priority from European Patent Application No. 03015970.1 filed Jul. 14, 2003, the entire disclosure of which is incorporated herein by reference. The present invention concerns a timepiece such as a wristwatch of the astronomical type, i.e. a watch capable of indicating the position of a celestial body of the solar system with respect to the Earth and to the constellations of the zodiac. A watch answering this definition is disclosed in European Patent No. 0 949 549 in the name of the Applicant. This watch includes in particular an hour hand and a minute hand, which move above a dial, which carries at its periphery an hour and minute scale and inside the latter, the symbols of the twelve signs of the zodiac. This watch also includes a rotating bezel bearing the symbols of the planets of the solar system. When the user wishes to know the position of a planet of the solar system with respect to the constellations of the zodiac, he rotates the bezel until the symbol of the celestial body that interests him is at 12 o'clock and he then presses the crown of a control stem. At that moment, the minute hand moves until it is placed in the position in which it indicates the celestial body in question and the approximate position thereof inside said zodiac sign, using the twelve signs of the zodiac and the hour and minute scale of the watch dial. If he so wishes, the user can repeat the same operations for one or several other celestial bodies. The major drawback of the astronomical watch described hereinbefore lies in the fact that it is not able to provide information allowing its user simply and quickly to find the position in the heavens of the celestial body that interests him. Indeed, this watch only provides an indication of the position of a given celestial body of the solar system with respect to the zodiac constellations. If the user then wishes to see the celestial body in question in the heavens, he will have to first of all identify the zodiac constellation designated for said body by his the watch. This assumes that the user is able to recognise the groups of stars corresponding to the various zodiac constellations, which is not within everyone's capabilities. It is an object of the present invention to overcome the aforementioned problem in addition to others by providing a watch, particularly a wristwatch, which enables a user to know at any time, when he so wishes, the position of a celestial body in the heavens and to be able easily to identify the position of said body in the heavens, without this requiring any particular astronomical knowledge on the user's part. The present invention therefore concerns an electronic astronomical watch, in particular of the wristwatch type, this watch being capable of indicating the position of celestial bodies in the heavens, said watch including: a time base for producing a standard frequency signal; means for determining the current time and date from the standard signal; means for selecting a celestial body; means for determining the position of the celestial body in the heavens and indicating this position via the display means, the watch being characterized in that it includes a rotating dial on which there is represented a map of the heavens and in that the shape of the hands is such that their intersection or their point of conjunction allows any point of the map of the heavens shown on the dial to be indicated. According to a complementary feature of the invention, the map of the heavens is a diagram of the constellations, particularly the twelve constellations of the zodiac and the stars visible from the earth. Owing to these features, the present invention provides an astronomical watch, which enables its user, not only to know the position of a celestial body with respect to the stars and constellations of the Milky Way, but also to know the position of the stars and constellations in the heavens. The user can thus, without needing any particular astronomical knowledge, identify, at the moment he so wishes, the position of the celestial body that interests him. According to another feature of the invention, the astronomical watch enables the position of the planets of the solar system to be identified. According to yet another feature, the watch includes a glass on which a horizon line is shown, which indicates to the user, at any time, the portion of the heavens that is visible from the place where he is situated. Owing to this further feature, identification of the celestial body of the solar system or any other celestial body, which interests the user, is made even simpler. According to yet another feature, the watch dial which carries the map of the heavens makes one complete revolution in 23 hours 56 minutes 4.09 seconds. The watch dial thus completes one revolution in a little less than 24 hours, to take account of the fact that the earth rotates around the sun in one year. The dial would make one complete revolution in 24 hours if one ignored the movement of the earth around the sun in one year, but in reality requires an adjustment of 3.94 minutes less, if one considers that one year equals 365.24 days, to take account of the contribution of 0.24 days of leap years. The watch is thus capable of determining, at the user's request, the positions of the various celestial bodies of the solar system with respect to the constellations at a determined date. Likewise, the watch is capable permanently of determining the position of the constellations in the heavens. Other features and advantages of the present invention will appear more clearly from the following detailed description of an example embodiment of the astronomical watch according to the invention, this example being given purely by way of illustrative and non-limiting example, with reference to the annexed drawing, in which: FIG. 1 is a plan view of the astronomical watch according to the present invention; FIG. 2 is a view illustrating the way in which the watch of FIG. 1 has to be used to identify a celestial body of the solar system in the heavens, and FIG. 3 is a block diagram illustrating the various functions of the watch shown in FIG. 1. The present invention proceeds from the general inventive idea consisting in providing an astronomical watch, which enables its user to identify, when he so wishes, the position of a celestial body in the heavens. Thus, the astronomical watch according to the invention essentially includes a rotating dial on which the map of the stars and the constellations is represented and a pair of hour and minute hands, whose shape is such that their point of intersection or conjunction allows any of the stars or constellations shown on the dial to be designated. After having selected the celestial body whose position he wishes to know, the user then need only consult the dial of his watch on which the point of intersection of the hands indicates to him in which constellation the celestial body that interests him is located. The fact that the dial carries a diagram of the heavenly vault visible from the place where the user is located enables him to easily identify the position of the celestial body that he is seeking in the heavens without needing any particular astronomical knowledge. In the following description, reference will be made to the identification of the position of the planets of the solar system in the heavens. It will be understood, however, that the invention is not limited to this embodiment and that it enables the position of any celestial body, such as a comet, or even an artificial satellite, to be identified. FIG. 1 shows a particular embodiment of the watch according to the invention. Designated as a whole by the general reference numeral 1, the watch of FIG. 1 is a wristwatch with an analogue display, which includes, in a conventional manner, a case 2 formed by a middle part 4 to which the two ends or two strands of a wristband 6 are attached, a glass 8, fixed to the front of this middle part 4 and a back cover, not visible in the drawing, which may be removable or provided with a hatch for introducing and changing a battery, which acts as the supply voltage source for watch 1. The display means of watch 1 include an hour hand 10 and a minute hand 12, which are each driven by a two-directional stepping motor and via a suitable gear train. These two hands 10 and 12 move above a rotating dial 14, which is driven by a third stepping motor in the two rotational directions via a suitable gear train. This dial 14 rotates about the same axis as hands 10 and 12 and completes one revolution in the anti-clockwise direction in a little less than 24 hours, very precisely 23 hours, 56 minutes and 4.09 seconds, in order to take account of leap years. According to one feature of the invention, a map of the heavens 16 is shown on dial 14. As the watch shown in FIG. 1 is intended to be used in the northern hemisphere, the map of the heavens 16 shown on dial 14 corresponds to the order of the constellations as seen on a latitude of 45° north, with the pole star 18 at the centre of said dial 14. Of course, for a watch intended to be used in the southern hemisphere, the heavens will be shown as they are seen on these latitudes. As can be seen upon examining FIG. 1, constellations 20, in particular the zodiac constellations, are not shown on dial 14 by their names or by pictograms, but by the star aggregates of which they are formed. The user thus permanently has available a complete map of the heavens as seen from the place where he is situated and which will be useful to him when he wishes to identify the position of a celestial body of the solar system, as will be explained in detail hereinafter. The Latin names of the twelve constellations of the zodiac are indicated on the periphery of rotating dial 14. In order to allow the user to better distinguish the constellations of the zodiac, the latter could be shown in another colour or with a thicker line than the other constellations appearing on the map of the heavens 16. Dial 14 moves facing a fixed scale 22 graduated with the hours and minutes and carrying a mark 24 placed at midday. This scale 22 surrounds dial 14 and is carried by a flange. In the particular embodiment of the invention shown in FIG. 1, the means for selecting a celestial body of the solar system include a control stem 26 provided with a crown 28 and a rotating bezel 30. Control stem 26 is a rotating stem, which can be moved axially between three positions, namely a stable neutral position, which corresponds to the normal operating position of the watch, a pulled out position that is also stable and an unstable pushed-in position in which a return spring permanently tends to return the stem to the neutral position. The axial and rotating movements of stem 26 are converted by switches into characteristic electric signals, which are sent to a control unit 32 (see FIG. 3) of the watch 1. As regards the rotational movements, these electric signals are pulse trains that allow the control unit to determine in which direction the stem has been rotated and whether the rotational speed is less or greater than a certain value, in other words whether the stem is being rotated slowly or quickly. Rotating bezel 30 is arranged such that fixed scale 22 is disposed concentrically between the rotating dial 14 and said bezel 30. This bezel 30 bears the symbols for the sun at 34, the moon at 36 and the various planets of the solar system at 38 including the earth at 40. The position of bezel 30 can be detected by any known device connected to control unit 32, like for example that described in European Patent No. EP-A-0 738 944, which is formed by magnets included in the bezel and Reed contacts placed inside watch 1. Moreover, it is clear that the symbols borne by rotating bezel 30 could be replaced by the names of these celestial bodies or any other representation allowing them to be identified. It will immediately be observed, upon examining FIG. 1, that hour hand 10 has a heart-shape that is different from the ordinary shapes given to watch hands, whereas the minute hand has the conventional straight shape. This answers a technical requirement, even if it can be linked to a concern of an aesthetic nature. Indeed, the shape of hands 10 and 12 is such that they can form a point of intersection above practically any of the points of the dial or a conjunction of their points facing one of said points. It is thus possible to address a particular point of the dial by controlling the movement of hour hand 10 and minute hand 12 in order to bring them to intersect or conjoin above that particular point. For more detail, reference can advantageously be made to the European Patent in the name of the Applicant filed under number 02080624.6, which is incorporated here by reference. Moreover, it will be realised in the following description that the particular shape of the hands of watch 1 according to the invention is used to designate accurately the point in the heavens shown on rotating dial 14 where the celestial body of the solar system, selected by the user, is located. Finally, it will be realised that an oval is added by any appropriate means such as, for example, by transfer printing, on the inside face of glass 8. This oval represents the horizon line 42, which delimits the visible part of the heavens from the place where the user of the watch is situated at a given time. The horizon line is calculated for a latitude of approximately 45° North, which enables the watch to be used with proper accuracy in North America, Europe and Asia. This having been said, the watch of FIG. 1 operates in the following manner: If the movement does not include position sensors, the position of hands 10, 12 and rotating dial 14 has to be initialised manually. Initialising the position of hour hand 10 and minute hand 12 is carried out by first of all rotating bezel 30 to bring the sun symbol 34 to midday, i.e. facing the mark 24 borne by fixed scale 22. Crown 28 is then pressed for quite a long time, for example more than 10 seconds, until hands 10, 12 move, then crown 28 is pulled out into the correction position. Crown 28 is then rotated clockwise to bring hour hand 10 to midday and anti-clockwise to bring minute hand 12 also to midday. Finally, crown 28 is pushed into the normal rest position. In order to initialise the position of rotating dial 14, in other words the map of the heavens 16, first of all bezel 30 is rotated to bring the moon phase symbol 36 to midday. Crown 28 is then pressed for more than 10 seconds, until the map of the heavens 16 moves, then crown 28 is rotated in one direction or another to bring a mark made on the map of the heavens 16 to face mark 24. Finally, crown 28 is pushed in to the normal rest position. Initialising the position of hands 10, 12 and rotating dial 14 can also be carried out automatically. For this purpose, the hour wheel and the minute wheel each include a plate with a peripheral toothing. A device for detecting the angular position of the hour and minute wheels includes a magnetic or capacitive sensor whose detection member, namely a flat spiral coil, is used for detecting a variation in the presence of matter, particularly a conductive metal conductor forming the plate. The plates each have at least one aperture whose angular position is determined by the detection device. For more details, reference could advantageously be made to European Patent No. EP-A 0 952 426, which is incorporated by reference in the present description. When the movement is encased, the detection device briefly described hereinbefore is activated. The apertures made in the hour and minute wheels are positioned above the detection members with an accuracy of one step, then the hour and minute hands are driven in at the midday position. The position of rotating dial 14 can be initialised in a similar way to that of hands 10, 12. In this case, rotating dial 14 is made of a moulded plastic material and includes a metal plate whose presence is detected by an inductive sensor mounted on a printed circuit board or “PCB”. The positioning accuracy of rotating dial 14, which carries the map of the heavens 16 is a function of the positioning accuracy of the metal plate and the inductive sensor. After having initialised the position of the hour and minute hands 10 and 12 and that of rotating dial 14 carrying map of the heavens 16, the universal time constant or “UTC” and the time of the place wear the person wearing it is located can also be indicated to the watch, in order to allow said watch to determine the time zone in which the wearer is situated, and the date. The UTC time is thus first adjusted. In order to do this, the “UTC” indication 44, which appears on rotating bezel 30, is brought to midday. It will be noted that in order to detect an angular position of rotating bezel 30, said bezel includes a certain number of permanent magnets, whereas magnetic switches of the REED contact type are arranged in the watchcase. The permanent magnets determine the open or closed binary state of the magnetic switches. The particular arrangement of the REED contacts and the permanent magnets has the effect that a particular arrangement of the REED contacts, different to the others, corresponds to each angular position of the rotating bezel, which allows unambiguous identification of the angular position occupied by said rotating bezel 30. For a full description of this device for detecting the angular position of rotating bezel 30, reference can usefully be made to U.S. Pat. No. 5,572,489, which is incorporated by reference in the present description. After having rotated the bezel and brought the “UTC” reference to midday, crown 28 is briefly pressed. Minute hand 12 does not move, whereas hour hand 10 indicates the “UTC” time (from 1 to 24 hours) on the fixed scale 22. From this UTC time read mode, one can enter UTC time correction mode by pulling out crown 28 into the correction position before the end of a delay time, which can be ten seconds. Minute hand 12 does not move, whereas hour hand 10 indicates the UTC time (from 1 to 24 hours) on fixed scale 22. The UTC time can then be corrected (hours and minutes) by rotating crown 28 in both directions. After correcting the UTC time, crown 28 is pushed in to its neutral rest position. In order to be able to orient map of the heavens 16, control unit 32 of watch 1 of the invention needs to know the current date from the place where the user is located. In order to correct the local time, crown 28 needs to be pulled out into the correction position. Minute hand 12 does not move and hour hand 10 indicates the time (from 1 to 24 hours) on fixed scale 22. Local time can then be corrected by rotating crown 28 in both directions. After correcting the local time crown 28 is pushed in to its neutral rest position hour hand 10 takes back its normal position. In order to be able to orient the map of the heavens 16 properly, control unit 32 also needs to know the current date. The date read mode will first be examined, then the correction mode for the latter. In order to read the date, bezel 30 is rotated in order to bring the earth symbol 40 to midday. After a brief application of pressure on crown 28, hands 10 and 12 are superposed and indicate the date from 1 to 31 on fixed scale 22. In order to read the month, one enters the date read mode. Before the end of a time delay that can be ten seconds, bezel 30 is rotated to bring the moon phase symbol 36 to midday. Hands 10, 12 are superposed and indicate the month from 1 to 12 on fixed scale 22. In order to read the year, one enters the date read mode. Before the end of the time delay, bezel 30 is rotated to bring the sun symbol 34 to midday. The hands are superposed and indicate the year from 1 to 60 on fixed scale 22. In order to correct the date, the month or the year, one has to be in the date, month or year read mode. Before the time delay ends, crown 28 has to be pulled out and the value corrected by rotating said crown in both directions. After correction, crown 28 is pushed in to the neutral rest position. Knowing the local time and the date, control unit 32 of watch 1 is able to orient the map of the heavens 16 in a suitable manner. In order to do this, control unit 32 has a memory 46 (see FIG. 3) which is a non-volatile memory programmed by the watch manufacturer and in which are stored the parameters concerning the stars and constellations, particularly the zodiac constellations, and the relative movements of the celestial bodies of the solar system with respect to the earth that the control unit needs. Moreover, the calculations that control unit 32 has to carry out to determine the positions of the celestial bodies using the aforementioned parameters are well known to those skilled in the art and there exist numerous works which can be consulted if necessary in order to programme control unit 32 in an appropriate manner. Among such works, one can cite for example “Astronomical Algorithms” by Jean Meeus, published by Willmann-Bell, Inc. Richmond, Va. 23235, in 1991 and “Landholt-Börstein; Numerical Data and Functional Relationships in Science and Technology”, group VI, volume 1, Spring Verlag, Berlin 1965. Naturally, since the watch is designed to provide other astronomical information, such as the phases of the moon, memory 46 also contains all the data necessary for control unit 32, which is also programmed for this. The watch includes (see FIG. 3) a time base 48, a circuit for determining the current time and date 50, control unit 32 with which data memory 46 is associated, a display control circuit 52, a display system 54, formed by the hour and minute hands 10 and 12, a manual control system 56 including stem 26 and bezel 30 and a direct current voltage source, for example a battery, not shown. Time base 48, which supplies a standard frequency signal to the time and date determination circuit 50 can advantageously be formed by a quartz oscillator like that usually used in electronic watches and which is formed by a quartz resonator and an electronic maintenance circuit, which allows the resonator to vibrate at a determined frequency. Current time and date determination circuit 50 includes a frequency divider as well as counters for the minutes, hours, days of the month, months and years. Moreover, circuit 50 contains the means necessary, on the one hand, for taking account of months with 28, 29, 30 and 31 days, in other words so that the watch is provided with a perpetual calendar and, on the other hand, for enabling the time and date to be corrected via control unit 32 to which this circuit is connected. Finally, circuit 50 is also designed to provide control unit 32 and, via the latter, display control circuit 52, with all the periodic signals produced by its frequency divider and which are needed by the latter to fulfil their various functions. Among the functions of unit 32, there is one that consists in determining, at the user's request, the positions of the various celestial bodies of the solar system other than the earth, with respect to the latter and to the stars and constellations on the current date. When control stem 26 is in the neutral position, hands 10, 12 display the current time. More specifically, the motors that drive hour hand 10 and minute hand 12 supply 180 pulses for one complete revolution of fixed scale 22. During normal operation of watch 1, minute hand 12 thus receives a drive pulse every 20 seconds, whereas hour hand 10 receives a drive pulse every 240 seconds During this same lapse of time, the position of these hands 10, 12 is accounted for by means of two counters, respectively for the hours and minutes, whose content is incremented by one steps of one unit from 0 to 179. the binary signals which represent the content of these counters thus allows control unit 32 of watch 1 to know the position of hour and minute hands 10, 12 at any time with respect to the position that the same hands 10, 12 would occupy during initialisation. Rotating dial 14 is driven by a gear train whose gear reduction ratio is close to 1000, which means that the dial has to make 1000 steps to complete one revolution on itself. The gear reduction ratio is chosen to be high such that dial 14 has better resistance to rotating shocks. Likewise, such a gear reduction ratio is well suited to driving dial 14 which is relatively heavy and which has to overcome significant friction forces. Moreover, as for hands 10, 12, a counter accounts for the position of rotating dial 14, in other words of map of the heavens 16, relative to the position that the latter occupied during the initialisation step. As previously stated, hour hand 10 has a heart-shape that differs from the usual shapes of watch hands. This particular configuration enables hour hand 10, whatever its angular position on rotating dial 14, to have a point of intersection with minute hand 12 which enables any point on the surface of said dial 14 to be designated. Thus, when the user chooses one of the celestial bodies of the solar system (with the exception of the earth, which is used for the date) shown on rotating bezel 30, and brings it to midday, then he exerts a short application of pressure on crown 28, the point of intersection of hands 10, 12 will indicate the position of the celestial body on the map of the heavens 16. The user need then only look at dial 14 of watch 1 by raising his arm and ensuring that geographic North is behind him (see FIG. 2) to identify the position of the celestial body of the solar system that interests him in the heavens. In doing this, the user will be helped by the horizon line 42 that appears on glass 8, which indicates to him the part of the heavens that is visible from the place where he is located at the moment when he consults his watch. In order to identify the position of the celestial body selected, control unit 32 has the current date, which will enable it to calculate the position occupied by said celestial body with respect to the constellations for said date. The position of the selected celestial body is identified on the surface of dial 14 by its polar coordinates, namely an angle and a radius. The position counter of map of the heavens 16 then indicates the position of said map 16 to control unit 32 and enables it to calculate the position to be given to the hands to bring them onto the desired point of dial 14. It goes without saying that the present invention is not limited to the embodiment that has just been described and that various simple modifications and variants can be envisaged by those skilled in the art without departing from the scope of the invention. | 20040708 | 20061226 | 20050120 | 70335.0 | 0 | KAYES, SEAN PHILLIP | ASTRONOMICAL TIMEPIECE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,886,514 | ACCEPTED | Communication system and method for an optical local area network | An optical local area network includes a passive optical distribution fabric interconnecting a plurality of nodes including a first node and a plurality of remaining nodes, a hub that includes the first node and a control module, and a client network adapter coupled to each of the remaining nodes for responding to the control module. The control module controls timing for each of the client network adapters to transmit signals over the passive optical distribution fabric and distribution of signals to each of the nodes. | 1. A method for broadcasting data comprising: receiving an incoming optical signal at a first port of a plurality of ports; converting the received incoming optical signal to an electrical signal; processing the electrical signal; converting the processed electrical signal to a broadcast optical signal; and coupling the broadcast optical signal to each of the plurality of ports. 2. The method of claim 1, wherein processing the electrical signal includes coupling the electrical signal to a device that processes the electrical signal according to an OSI layer-2 protocol. 3. The method of claim 1, wherein processing the electrical signal includes coupling the electrical signal to a device that processes the electrical signal according to an OSI layer-3 protocol. 4. The method of claim 1, further comprising converting an electrical client signal to the incoming optical signal. 5. The method of claim 4, further comprising adapting the electrical client signal from a signal conforming to an OSI layer-2 protocol. 6. The method of claim 5, wherein the OSI layer-2 protocol includes a media access control protocol. 7. The method of claim 6, wherein the media access control protocol is Ethernet or Fibre Channel. 8. The method of claim 1, further comprising transmitting the incoming optical signal from a network client adapter to one of the plurality of ports over an optical distribution fabric. 9. The method of claim 1, further comprising: transmitting the broadcast optical signal from one of the plurality of ports over an optical distribution fabric; and receiving the broadcast optical signal at network client adapters in a plurality of clients. 10. The method of claim 9, further comprising converting the received broadcast optical signal to a second electrical signal in at least one of the clients. 11. The method of claim 10, further comprising selecting a frame within the second electrical signal associated with the network client adapter and adapting data in the selected frame for transmission over a network interface. 12. An apparatus comprising: a plurality of ports; a passive optical coupler coupled to each of the plurality of ports; an optical-electrical converter in optical communication with the passive optical coupler; and a control module in electrical communication with the optical-electrical converter for scheduling slots for incoming and outgoing signals over the plurality of ports. 13. The apparatus of claim 12, wherein the control module is operable to schedule a slot for receiving a signal over one of the plurality of ports and to schedule a time for broadcasting a signal over each of the plurality of ports. 14. The apparatus of claim 12, including only a single optical-electrical converter in optical communication with the passive optical coupler. 15. The apparatus of claim 12, wherein the control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-2 protocol. 16. The apparatus of claim 12, wherein the control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-3 protocol. 17. An optical local area network comprising: a plurality of optical waveguides; a network manager that comprises an optical-electrical converter in optical communication with the plurality of optical waveguides; and a control module in electrical communication with the optical-electrical converter for scheduling slots for incoming and outgoing signals transmitted over the plurality of optical waveguides; and a plurality of network client adapters coupled to the plurality of optical waveguides, each network client adapter including an optical-electrical converter for processing transmitted and received optical signals at a client. 18. The optical local area network of claim 17, further comprising a passive optical coupler coupled to each of the plurality of optical waveguides. 19. The optical local area network of claim 17, wherein the network manager further comprises a passive optical coupler coupled to each of the plurality of optical waveguides. 20. The optical local area network of claim 17, wherein the control module is operable to schedule a slot for receiving a signal over one of the plurality of optical waveguides and to schedule a time for broadcasting a signal over each of the plurality of optical waveguides. 21. The optical local area network of claim 20, wherein the control module is operable to dynamically schedule a slot for receiving a signal over one of the plurality of optical waveguides in response to a message from one of the network client adapters. 22. The optical local area network of claim 17, wherein the control module is operable to determine a response delay between the optical-electrical converter and one of the network client adapters. 23. The optical local area network of claim 17, wherein the control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-2 protocol. 24. The optical local area network of claim 17, wherein the control module is coupled to a device that is operable to process an electrical signal provided by the optical- electrical converter according to an OSI layer-3 protocol. 25. The optical local area network of claim 17, wherein each of the network client adapters is operable to convert an electrical client signal to an optical signal for transmission over one of the optical waveguides. 26. The optical local area network of claim 25, wherein each of the network client adapters is operable to adapt the client signal from a signal conforming to an OSI layer-2 protocol. 27. The optical local area network of claim 26, wherein to the OSI layer-2 protocol includes a media access control protocol. 28. The optical local area network of claim 27, wherein the media access control protocol used by a network client adapter is Ethernet or Fibre Channel. 29. The optical local area network of claim 17, wherein each of the network client adapters is operable to convert a received optical signal to an electrical signal. 30. The optical local area network of claim 29, wherein each network client adapter is operable to select a frame within the electrical signal associated with the network client adapter. 31. The optical local area network of claim 17, further comprising a client that includes a network interface card, the network interface card including one of the network client adapters. 32. The optical local area network of claim 31, wherein the client is selected from the group consisting of a workstation, a personal computer, a disk storage array, a server, a switch, and a router. 33. An optical local area network comprising: a passive optical distribution fabric interconnecting a plurality of nodes including a first node and a plurality of remaining nodes; a hub that includes the first node and a control module; and a client network adapter coupled to each of the remaining nodes for responding to the control module; wherein the control module controls timing for each of the client network adapters to transmit signals over the passive optical distribution fabric and distribution of signals to each of the nodes. 34. The optical local area network of claim 33, wherein the control module is operable to schedule a slot for receiving a signal from one of the remaining nodes and to schedule a time for broadcasting a signal to each of the remaining nodes. 35. The optical local area network of claim 34, wherein the control module is operable to dynamically schedule a slot for receiving a signal from one of the remaining nodes in response to a message from one of the network client adapters. 36. The optical local area network of claim 33, wherein the control module is operable to determine a response delay between the hub and one of the network client adapters. 37. The optical local area network of claim 33, wherein the control module is coupled to a device that is operable to process signals according to an OSI layer-2 protocol. 38. The optical local area network of claim 33, wherein the control module is coupled to a device that is operable to process signals according to an OSI layer-3 protocol. 39. The optical local area network of claim 33, wherein each of the network client adapters is operable to convert an electrical signal to an optical signal for transmission over the passive optical transmission fabric. 40. The optical local area network of claim 39, wherein each of the network client adapters is operable to adapt a signal conforming to an OSI layer-2 protocol. 41. The optical local area network of claim 40, wherein OSI layer-2 protocol includes a media access control protocol. 42. The optical local area network of claim 41, wherein the media access control protocol used by a network client adapter is Ethernet or Fibre Channel. 43. The optical local area network of claim 33, wherein each of the network client adapters is operable to convert a received optical signal to an electrical signal. 44. The optical local area network of claim 43, wherein each network client adapter is operable to select a frame within the electrical signal associated with the network client adapter. 45. The optical local area network of claim 33, further comprising a client that includes a network interface card, the network interface card including one of the network client adapters. 46. The optical local area network of claim 45, wherein the client is selected from the group consisting of a workstation, a personal computer, a disk storage array, a server, a switch, and a router. 47. An optical local area network comprising: a hub; a plurality of external nodes interconnected by a passive optical distribution fabric, wherein the external nodes are located external to the hub, and the hub is operable to control traffic across all nodes; adaptors at each external node responsive to hub instruction; and an interface coupled to the hub coupling signals received from any individual external node for distribution to all external nodes. 48. The optical local area network of claim 47, wherein the hub includes an internal node coupled to the passive optical distribution fabric. 49. The optical local area network of claim 47, wherein the hub is operable to measure response delay between the hub and external nodes. 50. The optical local area network of claim 47, wherein the hub is operable to allocate slots for external nodes dynamically. 51. The optical local area network of claim 50, wherein slot allocations are made to guarantee external nodes have a minimum bandwidth. 52. The optical local area network of claim 47, further comprising splitters coupled between the hub and external nodes. 53. The optical local area network of claim 47, wherein traffic arriving at one or more external nodes includes Ethernet traffic. 54. The optical local area network of claim 47, wherein traffic arriving at one or more external nodes includes Fibre channel traffic. 55. The optical local area network of claim 47, wherein the hub includes an optical module. 56. The optical local area network of claim 47, wherein at least one of the external nodes is located within an optical module external to the hub. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 60/485,072 filed Jul. 3, 2003, incorporated herein by reference, and U.S. Provisional Application No. 60/515,836 filed Oct. 30, 2003, incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to optical fiber networks. BACKGROUND OF THE INVENTION A local-area network (LAN) is a computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. However, one LAN can be connected to other LANs over any distance often spanning an area greater than either LAN via telephone lines, coaxial cable, optical fiber, free-space optics and radio waves. A system of LANs connected in this way is commonly referred to as a wide-area network (WAN). SUMMARY OF THE INVENTION In general, in one aspect, the invention includes a method for broadcasting data including receiving an incoming optical signal at a first port of a plurality of ports; converting the received incoming optical signal to an electrical signal; processing the electrical signal; converting the processed electrical signal to a broadcast optical signal; and coupling the broadcast optical signal to each of the plurality of ports. Aspects of the invention may include one or more of the following features. Processing the electrical signal includes coupling the electrical signal to a device that processes the electrical signal according to an OSI layer-2 protocol. Processing the electrical signal includes coupling the electrical signal to a device that processes the electrical signal according to an OSI layer-3 protocol. The method further includes converting an electrical client signal to the incoming optical signal. The method further includes adapting the electrical client signal from a signal conforming to an OSI layer-2 protocol. The OSI layer-2 protocol includes a media access control protocol. The media access control protocol is Ethernet or Fibre Channel. The method further includes transmitting the incoming optical signal from a network client adapter to one of the plurality of ports over an optical distribution fabric. The method further includes transmitting the broadcast optical signal from one of the plurality of ports over an optical distribution fabric; and receiving the broadcast optical signal at network client adapters in a plurality of clients. The method further includes converting the received broadcast optical signal to a second electrical signal in at least one of the clients. The method further includes selecting a frame within the second electrical signal associated with the network client adapter and adapting data in the selected frame for transmission over a network interface. In general, in another aspect, the invention includes an apparatus including a plurality of ports; a passive optical coupler coupled to each of the plurality of ports; an optical-electrical converter in optical communication with the passive optical coupler; and a control module in electrical communication with the optical-electrical converter for scheduling slots for incoming and outgoing signals over the plurality of ports. Aspects of the invention may include one or more of the following features. The control module is operable to schedule a slot for receiving a signal over one of the plurality of ports and to schedule a slot for broadcasting a signal over each of the plurality of ports. The apparatus includes only a single optical-electrical converter in optical communication with the passive optical coupler. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-2 protocol. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-3 protocol. In general, in another aspect, the invention includes an optical local area network including a plurality of optical waveguides; a network manager that includes an optical-electrical converter in optical communication with the plurality of optical waveguides; and a control module in electrical communication with the optical-electrical converter for scheduling slots for incoming and outgoing signals transmitted over the plurality of optical waveguides; and a plurality of network client adapters coupled to the plurality of optical waveguides, each network client adapter including an optical-electrical converter for processing transmitted and received optical signals at a client. Aspects of the invention may include one or more of the following features. The optical local area network further includes a passive optical coupler coupled to each of the plurality of optical waveguides. The network manager further includes a passive optical coupler coupled to each of the plurality of optical waveguides. The control module is operable to schedule a slot for receiving a signal over one of the plurality of optical waveguides and to schedule a slot for broadcasting a signal over each of the plurality of optical waveguides. The control module is operable to dynamically schedule a slot for receiving a signal over one of the plurality of optical waveguides in response to a message from one of the network client adapters. The control module is operable to determine a response delay between the optical-electrical converter and one of the network client adapters. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-2 protocol. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-3 protocol. Each of the network client adapters is operable to convert an electrical client signal to an optical signal for transmission over one of the optical waveguides. Each of the network client adapters is operable to adapt the client signal from a signal conforming to an OSI layer-2 protocol. The OSI layer-2 protocol includes a media access control protocol. The media access control protocol used by a network client adapter is Ethernet or Fibre Channel. Each of the network client adapters is operable to convert a received optical signal to an electrical signal. Each network client adapter is operable to select a frame within the electrical signal associated with the network client adapter. The optical local area network further includes a client that includes a network interface card, the network interface card including one of the network client adapters. The client is selected from the group consisting of a workstation, a personal computer, a disk storage array, a server, a switch, and a router. In general, in another aspect, the invention includes an optical local area network including a passive optical distribution fabric interconnecting a plurality of nodes including a first node and a plurality of remaining nodes; a hub that includes the first node and a control module; and a client network adapter coupled to each of the remaining nodes for responding to the control module; wherein the control module controls timing for each of the client network adapters to transmit signals over the passive optical distribution fabric and distribution of signals to each of the nodes. Aspects of the invention may include one or more of the following features. The control module is operable to schedule a slot for receiving a signal from one of the remaining nodes and to schedule a slot for broadcasting a signal to each of the remaining nodes. The control module is operable to dynamically schedule a slot for receiving a signal from one of the remaining nodes in response to a message from one of the network client adapters. The control module is operable to determine a response delay between the hub and one of the network client adapters. The control module is coupled to a device that is operable to process signals according to an OSI layer-2 protocol. The control module is coupled to a device that is operable to process signals according to an OSI layer-3 protocol. Each of the network client adapters is operable to convert an electrical signal to an optical signal for transmission over the passive optical transmission fabric. Each of the network client adapters is operable to adapt a signal conforming to an OSI layer-2 protocol. The OSI layer-2 protocol includes a media access control protocol. The media access control protocol used by a network client adapter is Ethernet or Fibre Channel. Each of the network client adapters is operable to convert a received optical signal to an electrical signal. Each network client adapter is operable to select a frame within the electrical signal associated with the network client adapter. The optical local area network further includes a client that includes a network interface card, the network interface card including one of the network client adapters. The client is selected from the group consisting of a workstation, a personal computer, a disk storage array, a server, a switch, and a router. In general, in another aspect, the invention includes an optical local area network including a hub; a plurality of external nodes interconnected by a passive optical distribution fabric, wherein the external nodes are located external to the hub, and the hub is operable to control traffic across all nodes; adaptors at each external node responsive to hub instruction; and an interface coupled to the hub coupling signals received from any individual external node for distribution to all external nodes. Aspects of the invention may include one or more of the following features. The hub includes an internal node coupled to the passive optical distribution fabric. The hub is operable to measure response delay between the hub and external nodes. The hub is operable to allocate slots for external nodes dynamically. Slot allocations are made to guarantee external nodes have a minimum bandwidth. The optical local area network further includes splitters coupled between the hub and external nodes. Traffic arriving at one or more external nodes includes Ethernet traffic. Traffic arriving at one or more external nodes includes Fibre channel traffic. The hub includes an optical module. At least one of the external nodes is located within an optical module external to the hub. Implementations of the invention may include one or more of the following advantages. A network manager in an optical local area network can provide switching functions of a hub, a switch or a router. A switch configuration in which network managers are aggregated enables a high performance network in a compact apparatus. Connectivity of network managers and network client adapters to existing conventional routers and switches using industry standard form factor optical modules enables a high performance network upgrade with minimal new equipment. A network client switch can support multiple physical layer ports without necessarily requiring a Layer-2 MAC or switching elements and the associated routing tables and packet memory. The number of optical transceivers and switching elements used to sustain the same number of computing nodes in a LAN via a point-to-multipoint optically coupled network configuration is reduced, thus saving the majority of expense described above. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an optical local area network. FIGS. 2, 3A and 3B are schematic diagrams showing frame structures. FIG. 4 is a flowchart for a network operating process. FIG. 5 is a flowchart for a response delay process. FIGS. 6A-6C are diagrams of optical local area networks utilizing a hub configuration. FIGS. 7A-7D are diagrams of optical local area networks utilizing a switch configuration. FIG. 8 is a diagram of an optical local area network. FIGS. 9A and 9B are block diagrams of switches. DETAILED DESCRIPTION Referring to FIG. 1, a high-level schematic of an optical local area network 50 includes a network manager (NM) 100 at the head end of a passive optical distribution fabric (ODF) 102. The NM 100 acts as a central transmission point and an overall controlling device for the optical local area network 50. On another end, the ODF 102 is terminated by a plurality of (in one implementation, generally similar) network client adapters (NCAs) 104A, 104B, 104C. Herein the NCA 104A, NCA 104B, NCA 104C, are also referred to collectively as NCAs 104. Though three NCAs 104 are shown more or fewer NCAs may be included in the optical local area network 50. The NM 100 transmits/receives data to/from the NCAs 104 in the form of modulated optical light signals of known wavelength through the ODF 102. The transmission mode of the data sent over the ODF 102 may be continuous, burst or both burst and continuous modes. Both NM 100 and NCAs 104 may transmit light signals having a same wavelength. In one implementation, the light signals are polarized and the polarization of light transmitted by the NM 100 is perpendicular to the polarization of the light transmitted by the NCAs 104. Alternatively, the transmissions can be made in accordance with a time-division multiplexing scheme or similar protocol. In another implementation, bi-directional wavelength-division multiplexing (WDM) may be used. Bi-directional WDM is herein defined as any technique by which two optical signals having different wavelengths may be simultaneously transmitted bi-directionally with one wavelength used in each direction over a single fiber. In yet another implementation, bi-directional dense wavelength-division multiplexing (DWDM) may be used. Bi-directional DWDM is herein defined as any technique by which more than two optical signals having different wavelengths may be simultaneously transmitted bi-directionally with more than one wavelength used in each direction over a single fiber with each wavelength unique to a direction. For example, if bi-directional WDM is used, the NM 100 may transmit data to an NCA 104A, 104B, 104C utilizing a first wavelength of modulated light conveyed via a fiber 105A, 105B, 105C, respectively, in the ODF 102 and, similarly, the NCAs 104A, 104B, 104C may transmit data via the same fiber 105A, 105B, 105C, respectively, in the ODF 102 to the NM 100 utilizing a second wavelength of modulated light. Because only a single fiber is used (e.g., between the NM 100 and each respective NCA 104), this type of transmission system is commonly referred to as a bi-directional transmission system. Although the optical local area network 50 illustrated in FIG. 1 includes an NM 100 in communication with a plurality of NCAs 104 using a plurality of fibers, other implementations of optical local area networks 50 may be used. In some implementations, the NCAs 104 are generally similar. In other implementations, the NCAs 104 may differ in one or more aspects. The NM 100 includes network management communication logic and memory (NM-CLM) 106 block, a network management optical interface (NM Optical Interface) 108 block and an optical distribution fabric interface (ODF Interface) 110 block. The NM-CLM 106 includes a network manager engine (NM Engine) 112 block, a transmit framer (Tx Framer) 114 block and a receive framer (Rx Framer) 115 block. The NM Engine 112 is a control module that performs various processing and scheduling functions of an NM 100. The Tx Framer 114 frames outgoing data from the NM Engine 112 in accordance with a framing protocol that is in-use. The Rx Framer 115 receives incoming frames and recovers appropriate data and messages to pass on to the NM Engine 112. The NM Optical Interface 108 is controlled by the NM-CLM 106 using, for example, bus 109. The NM Optical Interface 108 converts electrical signals carrying data from the Tx Framer 114 to optical signals, for example, by modulating a laser (not shown) included in the NM Optical Interface 108 and transmitting the laser output to the ODF interface 110. The NM Optical Interface 108 also receives optical signals from the ODF interface 110 and converts the optical signals to electrical signals carrying data that is then transferred to the Rx Framer 115. Thus, the NM Optical Interface 108 functions as an “optical-electrical converter” that can convert a signal from an optical signal to electrical signal or from an electrical signal to an optical signal. The ODF Interface 110 includes an optical splitter 116 and a plurality of ODF Ports 117A, 117B, 117C, etc. For example, the optical splitter 116 can be a 1:n splitter (where n is at least 2) that splits light coming from the NM Optical Interface 108 into n portions of light coupled into n optical ports, respectively. The optical ports (e.g., ODF Ports 117) can be coupled to one or more optical waveguides. In one implementation, each ODF Port 117 is coupled to an optical waveguide. The optical waveguides can be, for example, single mode or multimode fibers that guide received/transmitted light to/from respective ODF Ports 117A, 117B, 117C, etc. The 1:n splitter (or equivalently, n:1 combiner) also directs light from any of the ODF Ports 117A, 117B, 117C, etc. received over one of the optical waveguides to the NM Optical Interface 108. ODF Ports 117A, 117B, 117C, etc. include optical fiber connector sockets (e.g., SC, LC, FC, ST, or MU connector sockets) for coupling to the optical waveguides. The ODF 102 can include any of a variety of passive optical components including optical fibers (e.g., single mode fibers, multimode fibers), optical connectors, fiber splices, passive branching components (e.g., passive splitters) and passive optical attenuators. In this implementation, the NCAs 104 each include a network client communication logic and memory (NC-CLM) 120 block, a network client optical interface (NC Optical Interface) 122 block and an ODF port 124. The NC-CLM 120 block includes an Adaptation Unit 126 block, a network client engine (NC Engine) 128 block, a transmit framer (Framer) 130 block and a receiver framer (Deframer) 131 block. The NC Engine 128 is a control module that performs various functions associated with an NCA 104, such as responding to messages from the NM 100. The Framer 130 frames outgoing data from the NC Engine 128 in accordance with a framing protocol that is in-use. The Deframer 131 receives incoming frames and recovers appropriate data and messages to pass on to the NC Engine 128. The adaptation unit 126 receives and transmits data and messages in the form of frames, packets or cells according to one or more external protocol(s). External controls, data and messages can be received using the network interface 136. The responsibilities of the adaptation unit 126 may include providing buffering, data and/or message filtering and translation between the external protocol(s) and the protocol of the optical local area network 50. The adaptation Unit 126 includes egress queue 132 block and ingress queue 133 block. Egress and ingress queues 132, 133 can be of the form of memory and are used for buffering receive and transmit data and messages, respectively. The adaptation unit 126 can filter out or drop data and/or messages that are not intended to egress through its network interface 136. Filtering can be based on the destination address of the data and/or messages according to the external protocol in-use. Additionally, the adaptation unit 126 can filter out or drop data and/or messages that are not intended to ingress through its network interface 136. Filtering can be based on equal values for the source and destination addresses of the data and/or messages according to the external protocol in-use. The NC Optical Interface 122 is controlled by the NC-CLM 128 using bus 134. The NC Optical Interface 122 converts electrical signals carrying data from the Framer 130 block to optical signals, for example, by modulating a laser (not shown) included in the NC Optical Interface 122 and transmitting the laser output to the ODF port 124. The NC Optical Interface 122 also receives optical signals from the ODF port 124 and converts the optical signals to electrical signals carrying data that is then transferred to the Deframer 131 block. The ODF port 124 includes an optical fiber connector socket (e.g., an SC, LC, FC ST, or MU connector socket). The NCAs 104 can be coupled to data link layer devices (not shown) or physical layer devices (not shown) using network interface 136. The data link layer devices and physical layer devices are network devices that operate at a Layer-2 or Layer-1 respectively, according to the Open Systems Interconnect (OSI) 7-layer reference model. Furthermore, these network devices may comply with industry standard specifications such as IEEE 802.3 and Fibre Channel (incorporated herein by reference). Consequently, the network interface 136 may be an MII, GMII, XGMII, XAUI or SPI type interface. Other Layer-2 and Layer-1 type interface specifications may also be used. The optical local area network 50 transfers data between an NM 100 and the NCAs 104 in the form of downstream frames (NM 100 to NCAs 104) and upstream “virtual frames” (NCAs 100 to NM 104). Downstream frames from the NM 100 are transmitted into the ODF 102 in an essentially continuous sequence of constant period frames. In one implementation, downstream frames have a period of 125 μs, and transfer data downstream at a rate of approximately 10 Gb/s, although other periods and rates may be used. The ODF Interface 110 and potentially the ODF 102 split the downstream transmissions passively so that all NCAs 104 receive the frames in a generally broadcast manner. In the upstream direction, separate transmissions from the plurality of NCAs 104 are transmitted as burst transmissions or in slots which are combined in a virtual frame so that the separate burst transmissions do not collide when they arrive at the NM 100. In one implementation, the virtual upstream frames have essentially the same period as the downstream frames, and upstream data transmissions are transmitted at a rate approximately equal to the downstream rate. Alternatively, different upstream and downstream rates may be used. FIG. 2 is a schematic timing and framing diagram, showing overall structure of a downstream frame 200, and a virtual upstream frame 202 in an implementation of a framing protocol. Referring now to FIGS. 1 and 2, each downstream frame 200 includes a header 204 and a payload section 206. The downstream header 204 includes a downstream synchronization (DS Sync) 208 section, a station management 210 section, two sections containing the number of NCAs 104 in communication with the NM 100 (# of NCAs) 212, 214 and an upstream slot allocation (US slot allocation) 216 section. The DS Sync 208 section includes a consecutive sequence of bits that enables receiving NCAs 104 to identify a beginning of the downstream frame 200 and thus acts as starting marker for frame timing throughout the optical local area network 50. The number of NCAs 104 in communication with the NM is sent twice 212, 214 to ensure correct interpretation of the US slot allocation section 216. The order of downstream header sections 210, 212, 214, 216 after a DS Sync 208 may differ in other implementations. During each network period 218 defined by respective adjacent downstream headers, each NCA 104 is able to send upstream data. The virtual upstream frame 202 is partitioned into slots, where a “slot” corresponds to a fixed number of bits or a fixed length of time within a virtual frame. For each network period 218, the NM 100 allocates each NCA 104 respective slots within which an NCA is able to transmit data upstream. Each slot allocation includes a start slot number and end slot number (also referred to as start time and end time), relative to the starting marker defined by a DS Sync 208 from the next network period after an NCA 104 receives a slot allocation. In alternative implementations, a start slot number and a length of time during which a specific NCA 104 is permitted to transmit may be sent instead of a start slot number and an end slot number. Slot allocation start and end numbers are allocated within the virtual upstream frame so that slot allocations do not overlap, ensuring that there are no collisions of data from different NCAs 104 at the NM 100. The allocations can be determined by the NM Engine 112 based on total upstream bandwidth requests and can be communicated to NCAs 104 in the downstream frame US slot allocation 216 section. The US slot allocation 216 section includes start and end slot numbers pertaining to and identified to specific NCAs 104 (as shown in 220 and 222). Slot allocations assigned to NCAs 104 can be dynamic and may be changed from network period to network period. The upstream frame 224 includes header 226 and payload 228 sections. The header 226 includes a preamble 230 section, a frame delimiter (Delimiter) 232 section and a station management 234 section. The preamble 230 section includes a consecutive sequence of bits designed to aid an NM 100 in synchronizing to the bit clock of a respective transmitting NCA 104. The Delimiter 232 includes a consecutive sequence of bits designed to aid an NM 100 in synchronizing to and recognizing the beginning of an upstream frame 224. Each downstream frame 200 and upstream frame 224 includes a payload section 206, 228 respectively, in which data to and from NCAs 104 (from the network interface 136) are transferred. FIG. 3A is a schematic showing the payload in downstream and upstream framing, showing that the payload of both upstream and downstream may contain a single adaptation data unit (ADU) 300. ADUs 300 are output units of data from an adaptation unit 126, where the adaptation unit 126 has processed data received from the network interface 136 for transfer across the optical local network 50. For example, in one implementation the adaptation unit 126 receives Ethernet media access control frames (MAC frames) via a GMII interface (as an implementation for the network interface 136) and removes the MAC frame's preamble and start of frame delimiter (SFD) fields with the remaining fields of the MAC frame encapsulated in an ADU 300. Additionally, in one implementation the adaptation unit 126 receives Fibre Channel (FC) FC-2 frames through a serial interface (as an implementation of the network interface 136) and removes the FC-2 frame's start of frame and end of frame fields with the remaining fields of the FC-2 frame encapsulated in an ADU 300. In another example, the adaptation unit 126 can receive IEEE 802.3 MAC frames via a GMII interface and form an ADU 300 with the entire MAC frame included (i.e., encapsulate the entire MAC frame). In yet another example, the adaptation unit 126 can receive FC-2 frames through a serial interface (as an implementation for the network interface 136) and form an ADU 300 with the entire FC-2 frame included (i.e., encapsulate the entire FC-2 frame). In one implementation, the payload 204, 232 of downstream frames 200 and upstream frames 224 may include multiple consecutive sub-frames. Referring to FIGS. 1 and 3B, a sub-frame includes a sub-frame header 302 section and a sub-frame payload 304 section. A sub-frame header 302 section includes a payload length indicator (PLI) 308 and cyclic redundancy check (CRC) 310 section that covers the PLI 308. CRC sections, although not shown, may be used in the downstream 200 and upstream 224 frames as well. The sub-frame payload 304 section includes a type 312 section, a CRC 314 that relates to the type 312 section, a payload data unit (PDU) 316 and optionally a CRC 318 that relates to the PDU 316. The PLI 308 gives an indication of the length, e.g., in bits, of the sub-frame payload 304 section immediately following the sub-frame header 302. The type 312 section gives an indication of the type of data in the PDU 316. An adaptation unit 126 may receive data from a mixture of protocols essentially simultaneously (as described below) and the use of sub-frames allows the data to be transferred across the network ensuring quality of service or class of service. An adaptation unit 126 uses sub-frames by placing received data in the PDU 316, indicating the type of data received in the type 312 section and entering the length of the sub-frame payload 304 in the PLI 308 section. The optical local area network 50 operates according to an exemplary process illustrated in FIG. 4. Referring now to FIGS. 1 and 4, after an NM 100 is powered on 400, the NM 100 sends out 402 one or more message(s) requesting new NCAs 104 (NCAs 104 that the NM 100 is unaware of) to identity themselves by reporting to the NM 100 with their respective serial number. The NM 100 also sends out 402 network parameters including initial NCA transmit power levels using, for example, a station management message(s). The NCAs 104 respond using slot allocation(s) given by the NM 100 for new NCAs 104 to respond. After successfully receiving new NCA serial numbers, the NM 100 assigns each new NCA 104 a network identification number (NC-ID) and requests 404 the new NCA 104 to adjust its transmitting power level. In one implementation, the NM 100 sends these requests in a station management message. The respective new NCAs 104 use the assigned NC-ID to interpret specific messages of concern (i.e., addressed) to a given NCA 104. The NM 100 initiates 406 a response delay process to determine the delay in responses between the new NCA and the NM 100. After performing 419 the response delay process, the NM 100 enters normal operation in which network data is transmitted and received 408 across the optical local area network 50. When an NCA 104 is powered on 410, the NCA 104 attempts to synchronize 412 to downstream frames by searching for the DS Sync 208. After successful downstream synchronization, the NCA 104 interprets 414 network parameters received via downstream station management messages 404, adjusts its initial transmit power level and awaits instructions (e.g., a message) for new NCAs 104. The instructions include a slot allocation for new NCAs 104 to respond 416 to the NM 100 with the NCA's 104 serial number. Once the NCA 104 has sent its serial number the NCA 104 is then assigned an NC-ID by the NM 100. The NCA 104 then enters a waiting loop (e.g., for a station management message from the NM 100 to adjust its transmit power level). In response to a request to set transmit power level, the NCA 104 adjusts the transmit power level 418. The NCA 104 then enters a waiting loop again (e.g., until receipt of a message from the NM 100 to initiate a response delay process). Upon receipt of an instruction to begin a response delay process, the NCA 104 can, in cooperation with the NM 100, determine the delay between the respective network elements (not shown as part of the process flow). The details of the response delay process are described in greater detail below. After the NCA 104 and NM 100 complete the response delay process, the NCA 104 may adjust 420 its alignment with the network period to account for downstream and upstream transmission delay. The NCA 104 then enters its normal operation state in which network data is received and transmitted 422. FIG. 5 shows one implementation for executing a response delay process 500. The response delay process 500, is a process to determine the delay in NM downstream transmission to NM upstream reception of a message or network data transmission. Referring now to FIGS. 1, 2 and 5, the NM 100 starts 501 the delay process with a new NCA 104 or with an NCA 104 that may cause upstream transmission collisions. The NM 100 assigns one or more slot(s) to the target NCA 104 (i.e., the new NCA or one NCA that may cause a collision in upstream communication) to respond with a response delay message. The NM 100 generates 502 a silence period in the upstream virtual frame 202 (e.g., by not assigning or granting any slots for that period) around the slot(s) assigned to the target NCA 104. The silence period ensures no upstream collisions will occur. The NM 100 sends 504 a message to the NCA 104 to respond with a response delay message and informs the NCA 104 of its slot(s) assignment to respond. Thereafter, the NCA 104 responds 506 to the NM 100 at the appropriate slot time. The NM 100 receives the NCA 104 response delay message and calculates 508 the transmission delay. In one implementation, the NM 100 transmits 510 the result of the response delay calculation to the NCA 104 and the NCA 104 aligns 512 itself to the proper network period. The NM 100 may assign, schedule or grant slot allocations in a number of ways (e.g. according to fixed time-division multiplex or statistical time-division multiplex schemes). In one implementation the slot allocations are scheduled to give the NCs 104 a guaranteed minimum upstream transfer rate. The rate may be determined by dividing the maximum upstream data rate by the number of NCAs 104. In another implementation, the NM 100 receives status information about the NCAs 104 egress 132 and ingress 133 queue status. The NM 100 can schedule slot allocations that best minimize the depth of the egress 132 and ingress 133 queues to minimize transmission delays ensuring quality of service (QOS) or class of service (COS). FIGS. 6A-6C, 7A-7C and 8 are illustrations of implementations of the optical local area network 50. In one implementation shown in FIG. 6A, an NM 100 may function in a hub configuration 600 networking clients including workstations 602, personal computers (PC) 604 and Ethernet switches 618 together using the Ethernet protocol. The workstations 602 and PCs 604 are connected to the hub configuration 600 with a network interface card (NIC) 606 containing an NCA 104 and a NIC controller 608. In one implementation of the NIC 606, the NIC controller 608 includes a GMII interface, an Ethernet MAC and a peripheral component interconnect (PCI) bus interface. The NCA 104 communicates to the NIC controller 608 through the GMII interface. Ethernet switches 618 are connected to the hub configuration 600 with a network adaptor 621A containing an NCA 104. Ethernet switches 618 can be conventional Ethernet switches. In one implementation of the network adaptor 621A, the network interface 136 is a GMII interface. In another implementation shown in FIG. 6B, the hub configuration 600 can network disk storage array devices 612, servers 614 and FC switches 619 together using the Fibre Channel (FC) protocol. This implementation may be described as a Storage Area Network (SAN). The disk storage array devices 612 and servers 614 are connected to the hub configuration 600 with a host bust adaptor (HBA) 607. In one implementation of HBA 607, the HBA controller 609 includes a serial interface, FC controller and a PCI bus interface. FC switches 619 are connected to the hub configuration 600 with a network adaptor 621B containing an NCA 104. FC switches 619 can be conventional FC switches. In one implementation of the network adaptor 621B, the network interface 136 is a serial interface. In yet another implementation of the optical local area network 50 shown in FIG. 6C, the hub configuration 600 may network clients such as workstations 602, PCs 604, disk storage array devices 612, servers 614 and switches 618, 619 (FIG. 6B) using both Ethernet and FC protocols concurrently. NICs 606 can connect a particular client to the hub configuration 600 using the Ethernet protocol. HBAs 607 can connect a particular client to the hub configuration 600 using the FC protocol. For example, workstations 602, PCs 604 and switches 618 can communicate with the hub configuration 600 using Ethernet protocol while disk storage array devices 612 and servers 614 can communicate with the hub configuration 600 using FC protocol. The ODF 102 (not shown) of the optical local area network 50 can include splitters 620. Hub configuration 600 can also connect to a switch 618 using an adaptor card 621A. Adaptor card 621A includes an NCA 104 with a respective network interface 136 (e.g., GMII, XAUI, Serial). Switch 618 may be, for example, a switch in a conventional Ethernet LAN 622. One or more NMs 100 can interface to a switching device (e.g., a Layer-2 switch or a Layer-3 switch) to process frames from the various NCAs 104 according to a communication protocol of the switching device. Referring to FIG. 7A, a switch configuration 704 includes multiple NMs 100A, 100B, 100C in communication with a Layer-2 switch device 700 which is in further communication with an uplink port 702. In alternative implementations, the Layer-2 switch device 700 may be in communication with a plurality of uplink ports (not shown). Though three NMs 100A, 100B, 100C are shown more or fewer NMs 100 may be in communication with a Layer-2 switch device 700 included in the switch configuration 704. Each NM 100A, 100B, 100C includes an adaptation unit 706 in communication with a NM Engine (not shown). The adaptation unit 706 receives and transmits data and messages in the form of frames, packets or cells according to the Layer-2 switch device 700 via a switch interface 708. Adaptation unit 706 can provide buffering, data and/or message filtering and translation between the protocol of the Layer-2 switch device 700 and the protocol of the optical local area network 50. The adaptation unit 706 includes an egress queue block (not shown) and an ingress queue block (not shown). Egress and ingress queues can be of the form of memory and are used for buffering receive and transmit data and messages, respectively. In one implementation of the NMs 100A, 100B, 100C, all upstream traffic received by an NM 100 is passed through the switch interface 708 to the Layer-2 switch device 700. All downstream traffic transmitted by an NM 100 is received by the NM 100 through the switch interface 708. In another implementation upstream traffic received by an NM 100 can be filtered based on destination address to either pass data and/or messages back to one or more NCAs 104 multiplexed in downstream traffic (e.g. hairpinning) or to the Layer-2 switch device 700 through the switch interface 708. The fiber connections 105 form a first ODF for connecting NM 100A with one or more NCAs. The fiber connections 710 form a second ODF for connecting NM 100B with one or more NCAs. The fiber connections 712 form a third ODF for connecting NM 100C with one or more NCAs. In one implementation of an optical local area network 50 shown in FIG. 7A, the switch configuration 704 is used to network workstations 602, PCs 604 and a Ethernet switch 618 together using the Ethernet protocol with appropriate NICs 606 as described above. The switch configuration 704 includes a Layer-2 switch (e.g., Layer-2 switch device 700) that implements an Ethernet MAC and switching functions. The optical fibers 105, 710, 712 connecting the workstations 602, PCs 604 and Ethernet switches 618 to the switch configuration 704 can be associated with different NMs 100A, 100B, 100C depending on which fiber connections are used. The uplink port 702 of switch configuration 704 can connect to an Ethernet switch and/or router (not shown). In another implementation of an optical local area network 50 shown in FIG. 7B, the switch configuration 704 is used to network one or more disk storage array devices 612, servers 614 and FC-2 switches 619 using, for example, the FC protocol with appropriate HBAs 607 as described above. This implementation may also be described as a Storage Area Network (SAN). The switch configuration 704 includes a Layer-2 switch (e.g., Layer-2 switch device 700) that implements an FC-2 controller and switching functions. The optical fibers 105, 710, 712 connecting the disk storage array devices 612, servers 614 and FC-2 switch 619 to the switch configuration 704 can be associated with different NMs 100A, 100B, 100C depending on which fiber connections are used. The uplink port 702 of switch configuration 704 may connect to an FC-2 switch and/or router (not shown). FC-2 switches 619 can be a conventional FC-2 switch. In yet another implementation of an optical local area network 50 shown in FIG. 7C, a switch configuration 704 is used to network workstations 602, PCs 604, disk storage array devices 612, servers 614 and other switches (e.g. an Ethernet switch 618) together using, for example, both Ethernet and FC protocols concurrently in a manner described previously. The switch configuration 704 includes a Layer-2 switch (e.g. Layer-2 switch device 700) that implements both an Ethernet MAC and FC-2 controller with switching functions. Layer-2 switch device 700 can be implemented by a packet processor or network processor. The optical fibers 105, 710, 712 connecting the workstations 602, PCs 604, disk storage array devices 612, servers 614 and t switches to the switch configuration 704 can be associated with different NMs 100A, 100B, 100C depending on which fiber connections are used. The uplink port 702 of switch configuration 704 may connect to an Ethernet or FC-2 switch and/or router (not shown). In yet another implementation of an optical local area network 50, an implementation of switch configuration 705 containing an NM 100, an adaptation unit 706 and an uplink port 702 is shown in FIG. 7D. Switch configuration 705 can be used to network workstations 602, PCs 604 and other switches 618 in a manner described previously. The NM 100 is in communication with a Layer-2 switch device (not shown) through the uplink port 702 that is connected to a switch. The connection between uplink port 702 and switch 618 can be a physical layer connection 714 (e.g., 1000 BASE-SX, 1000 BASE-LX). Ethernet switch 618 can be a conventional Ethernet switch. In some implementations of switch configurations 704, 705 the uplink port 702 can be an NCA adaptor (not shown) similar to 621A, 621B wherein the network interface 136 and switch interface 708 are coupled using the same interface standard (e.g., XAUI, Serial, Parallel), thus enabling the uplink port 702 to connect to other hub configurations 600 and switch configurations 704 (FIGS. 7A-7C), 705 (FIG. 7D). In another implementation of an optical local area network 50 shown in FIG. 8, NM 100 and NCA 104 may be implemented in optical modules. A network manager in an optical module (NM-OM) 800 is provided that, in one implementation, conforms to an industry standard form factor and includes an NM-CLM 803 that includes an adaptation unit 706 to transfer data into and out of a network interface (e.g., switch interface 708). The NM-OM 800 also includes a NM Optical interface 108 and an ODF port 117A. In one implementation, the optical module NM-OM 800 conforms to an industry standard Multi-source agreement (MSA) form factor (e.g., 300 pin, XENPAK, X2, XPAK, XFP or SFP). A network client adaptor in an optical module (NC-OM) 802 can be provided that, in one implementation, also conforms to an industry standard form factor and includes an NCA 104. For example, the optical module NC-OM may conform to an MSA form factor (e.g., 300 pin, XENPAK, X2, XPAK, XFP or SFP). The NM-OM 800 can connect to a conventional router 804 that has optical module ports 806 using the router's switch interface (e.g., XAUI or Serial). The NM-OM 800 is in optical communication with an optical splitter 810 that splits light among and collects light from workstations 602, PCs 604, disk storage array devices 612, servers 614 and switches using appropriate NICs 606 and/or NC-OM 802 as previously described. The Ethernet Layer-2/3 switch 808 may be of conventional design and include an uplink port, that in one implementation, conforms to an industry standard optical module form factor. The Ethernet Layer-2/3 switch 808 can communicate with the NM-OM 800 in router 804 by using an NC-OM 802 via network interface 136 (e.g., XAUI or Serial). The Ethernet Layer-2/3 switch 808 is further detailed in FIG. 9A. In the Ethernet Layer-2/3 switch 808, an NC-OM 802 is in communication with a Layer-2 switch 900 by means of a MAC (not shown) using a network interface 136 (e.g., XAUI or Serial). Ethernet Layer-2/3 switch 808 also includes physical layer ports (PHY ports) 902 that, in one implementation, form a conventional Ethernet LAN (e.g., Ethernet LAN 622 of FIG. 8) connecting network clients such as workstations 602 and PCs 604. An implementation of an alternative configuration for a switch is shown in FIG. 9B. FIG. 9B is an illustration of an NC-Switch 910, in which no conventional Layer-2 switch and MAC is used. NC-Switch 910 includes an NCA 912 and multiple PHY ports 902. Each PHY port may perform wireline (e.g., 10/100/1000 BASE-T, DSL) or wireless (e.g., IEEE 802.11, IEEE 802.16) physical layer communications with conventional LAN clients. In this implementation, the adaptation unit 126 supports multiple network interfaces 136. The switching function previously performed by the Layer-2 switch (e.g., Layer-2 switch 900 of FIG. 9A) is consolidated to the switch or router in communication with an NM 100 in a switch configuration 704 (as described above) or an NM-OM 800 (e.g. as illustrated in FIG. 8 an NC-Switch 910 in communication with an NM-OM 800). Alternatively, the switching function previously performed by the Layer-2 switch is consolidated to Layer-2 switches (not shown) in communication with other NCAs 104 networked in a hub configuration 600. In hub configuration 600 (e.g. FIGS. 6A-6C) of the optical local area network 50, flow control, denial of service and other network administration functions are dependent on external Layer-2 devices in communication with NCAs 104 (for example, the Ethernet MAC or FC-2 controller in the NIC controller 608 dependent on the implementation as previously discussed). In switch configurations 704 (e.g. FIGS. 7A-7C) of the optical local area network 50, flow control, denial of service and other network administration functions are further dependent on the external Layer-2 device 700 in communication with NMs 100, in addition to the Layer-2 devices external and in communication with NCAs 104 as previously mentioned. Although the invention has been described in terms of particular implementations, one of ordinary skill in the art, in light of this teaching, can generate additional implementations and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>A local-area network (LAN) is a computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. However, one LAN can be connected to other LANs over any distance often spanning an area greater than either LAN via telephone lines, coaxial cable, optical fiber, free-space optics and radio waves. A system of LANs connected in this way is commonly referred to as a wide-area network (WAN). | <SOH> SUMMARY OF THE INVENTION <EOH>In general, in one aspect, the invention includes a method for broadcasting data including receiving an incoming optical signal at a first port of a plurality of ports; converting the received incoming optical signal to an electrical signal; processing the electrical signal; converting the processed electrical signal to a broadcast optical signal; and coupling the broadcast optical signal to each of the plurality of ports. Aspects of the invention may include one or more of the following features. Processing the electrical signal includes coupling the electrical signal to a device that processes the electrical signal according to an OSI layer-2 protocol. Processing the electrical signal includes coupling the electrical signal to a device that processes the electrical signal according to an OSI layer-3 protocol. The method further includes converting an electrical client signal to the incoming optical signal. The method further includes adapting the electrical client signal from a signal conforming to an OSI layer-2 protocol. The OSI layer-2 protocol includes a media access control protocol. The media access control protocol is Ethernet or Fibre Channel. The method further includes transmitting the incoming optical signal from a network client adapter to one of the plurality of ports over an optical distribution fabric. The method further includes transmitting the broadcast optical signal from one of the plurality of ports over an optical distribution fabric; and receiving the broadcast optical signal at network client adapters in a plurality of clients. The method further includes converting the received broadcast optical signal to a second electrical signal in at least one of the clients. The method further includes selecting a frame within the second electrical signal associated with the network client adapter and adapting data in the selected frame for transmission over a network interface. In general, in another aspect, the invention includes an apparatus including a plurality of ports; a passive optical coupler coupled to each of the plurality of ports; an optical-electrical converter in optical communication with the passive optical coupler; and a control module in electrical communication with the optical-electrical converter for scheduling slots for incoming and outgoing signals over the plurality of ports. Aspects of the invention may include one or more of the following features. The control module is operable to schedule a slot for receiving a signal over one of the plurality of ports and to schedule a slot for broadcasting a signal over each of the plurality of ports. The apparatus includes only a single optical-electrical converter in optical communication with the passive optical coupler. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-2 protocol. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-3 protocol. In general, in another aspect, the invention includes an optical local area network including a plurality of optical waveguides; a network manager that includes an optical-electrical converter in optical communication with the plurality of optical waveguides; and a control module in electrical communication with the optical-electrical converter for scheduling slots for incoming and outgoing signals transmitted over the plurality of optical waveguides; and a plurality of network client adapters coupled to the plurality of optical waveguides, each network client adapter including an optical-electrical converter for processing transmitted and received optical signals at a client. Aspects of the invention may include one or more of the following features. The optical local area network further includes a passive optical coupler coupled to each of the plurality of optical waveguides. The network manager further includes a passive optical coupler coupled to each of the plurality of optical waveguides. The control module is operable to schedule a slot for receiving a signal over one of the plurality of optical waveguides and to schedule a slot for broadcasting a signal over each of the plurality of optical waveguides. The control module is operable to dynamically schedule a slot for receiving a signal over one of the plurality of optical waveguides in response to a message from one of the network client adapters. The control module is operable to determine a response delay between the optical-electrical converter and one of the network client adapters. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-2 protocol. The control module is coupled to a device that is operable to process an electrical signal provided by the optical-electrical converter according to an OSI layer-3 protocol. Each of the network client adapters is operable to convert an electrical client signal to an optical signal for transmission over one of the optical waveguides. Each of the network client adapters is operable to adapt the client signal from a signal conforming to an OSI layer-2 protocol. The OSI layer-2 protocol includes a media access control protocol. The media access control protocol used by a network client adapter is Ethernet or Fibre Channel. Each of the network client adapters is operable to convert a received optical signal to an electrical signal. Each network client adapter is operable to select a frame within the electrical signal associated with the network client adapter. The optical local area network further includes a client that includes a network interface card, the network interface card including one of the network client adapters. The client is selected from the group consisting of a workstation, a personal computer, a disk storage array, a server, a switch, and a router. In general, in another aspect, the invention includes an optical local area network including a passive optical distribution fabric interconnecting a plurality of nodes including a first node and a plurality of remaining nodes; a hub that includes the first node and a control module; and a client network adapter coupled to each of the remaining nodes for responding to the control module; wherein the control module controls timing for each of the client network adapters to transmit signals over the passive optical distribution fabric and distribution of signals to each of the nodes. Aspects of the invention may include one or more of the following features. The control module is operable to schedule a slot for receiving a signal from one of the remaining nodes and to schedule a slot for broadcasting a signal to each of the remaining nodes. The control module is operable to dynamically schedule a slot for receiving a signal from one of the remaining nodes in response to a message from one of the network client adapters. The control module is operable to determine a response delay between the hub and one of the network client adapters. The control module is coupled to a device that is operable to process signals according to an OSI layer-2 protocol. The control module is coupled to a device that is operable to process signals according to an OSI layer-3 protocol. Each of the network client adapters is operable to convert an electrical signal to an optical signal for transmission over the passive optical transmission fabric. Each of the network client adapters is operable to adapt a signal conforming to an OSI layer-2 protocol. The OSI layer-2 protocol includes a media access control protocol. The media access control protocol used by a network client adapter is Ethernet or Fibre Channel. Each of the network client adapters is operable to convert a received optical signal to an electrical signal. Each network client adapter is operable to select a frame within the electrical signal associated with the network client adapter. The optical local area network further includes a client that includes a network interface card, the network interface card including one of the network client adapters. The client is selected from the group consisting of a workstation, a personal computer, a disk storage array, a server, a switch, and a router. In general, in another aspect, the invention includes an optical local area network including a hub; a plurality of external nodes interconnected by a passive optical distribution fabric, wherein the external nodes are located external to the hub, and the hub is operable to control traffic across all nodes; adaptors at each external node responsive to hub instruction; and an interface coupled to the hub coupling signals received from any individual external node for distribution to all external nodes. Aspects of the invention may include one or more of the following features. The hub includes an internal node coupled to the passive optical distribution fabric. The hub is operable to measure response delay between the hub and external nodes. The hub is operable to allocate slots for external nodes dynamically. Slot allocations are made to guarantee external nodes have a minimum bandwidth. The optical local area network further includes splitters coupled between the hub and external nodes. Traffic arriving at one or more external nodes includes Ethernet traffic. Traffic arriving at one or more external nodes includes Fibre channel traffic. The hub includes an optical module. At least one of the external nodes is located within an optical module external to the hub. Implementations of the invention may include one or more of the following advantages. A network manager in an optical local area network can provide switching functions of a hub, a switch or a router. A switch configuration in which network managers are aggregated enables a high performance network in a compact apparatus. Connectivity of network managers and network client adapters to existing conventional routers and switches using industry standard form factor optical modules enables a high performance network upgrade with minimal new equipment. A network client switch can support multiple physical layer ports without necessarily requiring a Layer-2 MAC or switching elements and the associated routing tables and packet memory. The number of optical transceivers and switching elements used to sustain the same number of computing nodes in a LAN via a point-to-multipoint optically coupled network configuration is reduced, thus saving the majority of expense described above. | 20040706 | 20110412 | 20050210 | 91061.0 | 1 | LI, SHI K | COMMUNICATION SYSTEM AND METHOD FOR AN OPTICAL LOCAL AREA NETWORK | SMALL | 0 | ACCEPTED | 2,004 |
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10,886,548 | ACCEPTED | Starter having structure for preventing overheating | A starter for cranking an internal combustion engine is composed of an electric motor, an output shaft driven by the motor, a pinion gear coupled to the output shaft, and a magnetic switch. Electric power is supplied to the motor from an on-board battery through a switch, a movable contact of which is driven by the magnetic switch. The movable contact is connected to a brush lead wire via a connection formed by soft-soldering. The connection formed by the soft-soldering is positioned close to the commutator and covered with an end cover, so that the temperature of the connection becomes higher than other places in the starter. The connection easily melts away to thereby shut off power supply to the motor when its temperature becomes unusually high, and thereby the starter is protected from overheating. | 1. A starter for cranking an internal combustion engine having a ring gear, the starter comprising: an electric motor having a stator for providing a magnetic field and an armature adapted to rotate in the stator, the stator including a cylindrical yoke forming a magnetic circuit, the armature including a commutator with which brushes are slidably in contact to supply electric current to the armature; a magnetic switch including a coil for generating a magnetic force by supplying electric current thereto and a plunger disposed in the coil and driven by the magnetic force; an electric circuit for supplying electric current to the armature from a battery; a switch for selectively opening and closing the electric circuit according to movement of the plunger, the switch including a stationary contact connected to the battery and a movable contact connected to the brush via a brush lead wire, wherein: one end of the brush lead wire is electrically and mechanically connected to the brush and the other end of the lead wire is directly connected to the movable contact by soft-soldering. 2. The starter for cranking an internal combustion engine as in claim 1, wherein: the movable contact is positioned in the vicinity of the brush. 3. The starter for cranking an internal combustion engine as in claim 1, further including an auxiliary switch connected in parallel to the switch, wherein: the auxiliary switch is adapted to be closed, before the switch is closed, to supply electric current, an amount of which is smaller than that supplied when the switch is closed, to the armature; and the auxiliary switch is positioned in the vicinity of the movable contact of the switch. 4. The starter for cranking an internal combustion engine as in claim 1, wherein: one axial end of the cylindrical yoke is closed with an end cover; and the switch and the magnetic switch are contained in and covered with the end cover. 5. The starter for cranking an internal combustion engine as in claim 3, wherein: one axial end of the cylindrical yoke is closed with an end cover; and the switch, the auxiliary switch and the magnetic switch are contained in and covered with the end cover. 6. The starter for cranking an internal combustion engine as in claim 1, the starter further comprising: an output shaft driven by the electric motor; a pinion unit coupled to the output shaft by means of a helical spline; a pinion-rotation-restricting member adapted to engage with the pinion unit to restrict rotation of the pinion unit; and a crank bar rotatively driven by the plunger for bringing the pinion-rotation-restricting member into engagement with the pinion unit, thereby thrusting the pinion unit on the output shaft toward the ring gear of the internal combustion engine and establishing engagement between the pinion unit and the ring gear. 7. The starter for cranking an internal combustion engine as in claim 3, the starter further comprising: an output shaft driven by the electric motor; a pinion unit coupled to the output shaft by means of a helical spline; a pinion-rotation-restricting member adapted to engage with the pinion unit to restrict rotation of the pinion unit; and a crank bar rotatively driven by the plunger for bringing the pinion-rotation-restricting member into engagement with the pinion unit, thereby thrusting the pinion unit on the output shaft toward the ring gear of the internal combustion engine and establishing engagement between the pinion unit and the ring gear, wherein: the pinion-rotation-restricting member is brought into engagement with the pinion unit before the auxiliary switch is closed; then the auxiliary switch is closed to slowly rotate the output shaft, thereby thrusting the pinion unit toward the ring gear and establishing engagement between the pinion unit and the ring gear; and then the main switch is closed to supply a full current to the electric motor and to crank up the engine. | CROSS-REFERENCE TO RELATED APPLICATION This application is based upon and claims benefit of priority of Japanese Patent Application No. 2003-316414 filed on Sep. 9, 2003, the content of which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter for cranking an internal combustion engine, and more particularly to a starter that includes a structure for preventing overheating. 2. Description of Related Art It has been becoming a serious problem that the earth is being warmed up by carbon dioxide contained in the atmosphere. To cope with this problem by reducing fuel consumption in an automobile vehicle, great efforts are being made in downsizing automotive parts and components. In a starter motor for cranking an engine, its size and weight have been considerably reduced. On the other hand, the downsizing brings a problem of overheating. To overcome the overheating problem, various measures, such as improving heat-durability of materials used in the starter, have been taken. Such measures, however, have not been sufficiently effective to overcome the overheating problem. If it is difficult to start an engine, or if a key-switch does not return to its original position, a large amount of current, such as several hundreds amperes, continues to flow through a starter for a long time. If this happens, the starter overheats and a further serious problem may follow. If a switch for supplying current to the starter is not opened due to its malfunction after the engine is successfully cranked up, several tens amperes may be continuously supplied to the starter. In this case, the starter continues to rotate at a high speed. Not only the starter is overheated but also commutator segments may be separated from a commutator surface by a high centrifugal force applied thereto. This may results in a complete loss of the starter. Various proposals have been made as to ways and methods to shut off the current supply to the starter under such accidental situations mentioned above. For example, JP-A-10-66311 and WO-02/16763A1 propose to provide a fuse that melts away when the starter is overheated. Such a fuse may be provided in a main circuit for supplying current to the starter or in a pig tail connecting brushes. The fuse may be formed by reducing a cross-sectional area of a certain portion of the circuit. On the other hand, DE-10044081A1 and JP-A-59-185869 propose to form a solder-connection at certain position of a main circuit for supplying current to the starter, so that current supply is shut down by deformation or melting of the solder-connection when the starter is overheated. The overheating problem, however, has not been sufficiently solved by those proposals. When the proposed fuse is used in the starter circuit, the fuse is blown away at a certain amount of current peculiar to that fuse. The amount of current flowing through the starter under no load condition is several tens amperes, while the amount of current is as high as several hundreds amperes when the starter is continuously operated without succeeding in cranking up the engine. Therefore, it is difficult to shut down the current in various levels with a single fuse. That is, if the fuse is designed to be blown at several hundreds of amperes, it is successfully blown by a high level of current, but it is not blown by a low current such as several tens of amperes. On the other hand, if the fuse is designed to be blown by a low level current, there is a possibility that the current supply is unnecessary shut down. In addition, it is unavoidable that a resistance in the circuit is increased by such a fuse, resulting in decrease in the starter output. Because a large amount of current usually flows in the starter, the starter output is considerably reduced if there is an increase in resistance even in a small amount. To compensate such output decrease, the starter has to be made larger, which is contradictory to the downsizing. In the technology of forming the solder-connection in the main circuit (proposed by DE-10044081A1 and JP-A-59-185869), it is expected that the solder-connection is deformed or disconnected without fail before components of the starter are damaged by overheating. For this purpose, the solder-connection has to be formed at a position where temperature is the highest and at a position that is closest to a power source such as a battery. Usually, the position where the temperature is the highest is a commutator surface which brushes slidably contact. However, it is difficult to form the solder-connection at a place where constant heat conduction from the commutator surface can be expected. JP-A-59-185869 shows a solder-connection formed between a terminal bolt of a magnetic switch and a stationary contact. It further shows a resilient member for forcibly separating the circuit when the solder-connection melts away at a high temperature. DE-10044081A1 also proposes a similar resilient member for separating two contacts between which a solder-connection is formed. However, since the solder-connection is positioned, in both proposals, at a place far from a heat generating point, there is a possibility that an electric motor in the starter is damaged before the solder-connection shuts off the current supply. Further, since the resilient member is used in both proposals, a larger number of parts is required, resulting in a higher manufacturing cost. Further, DE-10044081 proposes to connect brushes and pig tails with solder. However, since the solder-connections are located far from the power source, it is difficult to shut off the current supply before other parts are damaged by heat. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide an improved compact starter in which power supply is shut off without fail when the starter is about to overheat. The starter for cranking an internal combustion engine is composed of an electric motor, an output shaft driven by the electric motor, a pinion gear spline-coupled to the output shaft, and a magnetic switch for engaging the pinion gear with a ring gear of the engine and for supplying electric current to the electric motor. The electric motor includes a stator for providing a magnetic field and an armature rotating in the stator. The armature has a commutator with which brushes are slidably in contact to thereby supply electric current to the armature from an on-board battery. In the power supply circuit, a switch having a stationary contact and a movable contact driven by a plunger of the magnetic switch is disposed. The movable contact is connected to the brush through a brush lead wire. On end of the brush lead wire is mechanically and electrically connected to the brush and the other end of the brush lead wire is directly connected to the movable contact by soft-soldering which is formed at a low temperature such as 300° C. The connection formed by the soft-soldering is positioned in the vicinity of the commutator which generates a large amount of heat. The magnetic switch and the switch are enclosed in an end cover not to be cooled, so that the connection formed by the soft-soldering reaches a high temperature when the starter is about to overheat. Further, the brush lead wire is so made that a certain pulling force is applied to the movable contact when the switch is closed. Since the connection formed by the soft-soldering is located close to the commutator and heat generated on the commutator surface is easily conducted to the connection through the brush lead wire, the temperature of the connection easily becomes high under unusual situations, e.g., when current is continuously supplied to the electric motor for some reasons. Further, since the connection is enclosed by the end cover, the heat of the connection is not easily dissipated. Therefore, the connection formed by the soft-soldering melts away before other components of the starter are damaged by heat. In addition, since there is a force pulling away the brush lead wire from the connection, the brush lead wire is quickly separated from the movable contact when the connection melts away. Therefore, it is not necessary to provide a resilient member for separating the lead wire from the movable contact. An auxiliary switch may be connected in parallel to the switch in the power supply circuit. In this case, the auxiliary switch is adapted to close before the switch is closed and to supply a limited amount of current to the electric motor, so that a process of establishing engagement between the pinion gear and the ring gear is slowly performed. The present invention is advantageously applied to a starter, a pinion gear of which is engaged with a ring gear of the engine while restricting rotation of the pinion gear. Other objects and features of the present invention will become more readily apparent from a better understanding of the preferred embodiments described below with reference to the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a starter for cranking an internal combustion engine, as a first embodiment of the present invention; FIG. 2 is a perspective view showing a structure for holding a movable contact; FIG. 3 is a plan view showing a connection between a movable contact and a brush lead wire, the connection being made by soft-soldering; FIG. 4 is a circuit diagram showing electric connections in the starter; FIG. 5 is a cross-sectional view showing a rear portion of a starter, as a second embodiment of the present invention; and FIG. 6 is a circuit diagram showing electrical connections in the starter shown in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1-4. FIG. 1 shows a starter 1 for cranking an internal combustion engine, to which the present invention is applied. This starter 1 is a so-called pinion-rotation-restricting type starter that is used for cranking a relatively small engine. The starter 1 is composed of: an electric motor 2 generating rotational torque; an output shaft 3 driven by the electric motor 2; a pinion unit 4 slidably coupled to the output shaft 3; a pinion-rotation-restricting member 5 that engages with the pinion unit 4 for restricting its rotation; a magnetic switch 7 that controls electric power supply to the electric motor 2 in an ON-and-OFF fashion and operation of the pinion-rotation-restricting member 5; and other associated components. The magnetic switch 7 includes a switch A (that will be described latter in detail) having a stationary contact 33 and a movable contact 35. The electric motor 2 is a known type of motor that is composed of a stator 8 for supplying a magnetic field and an armature 10 rotatably disposed in the stator 8, the armature 10 having a commutator 9 through which electric current is supplied to the armature via brushes 11. The electric motor 2 is held between a front housing 12 and the end cover 13. The stator 8 is composed of a cylindrical yoke 8a and permanent magnets 8b disposed inside of the yoke 8a. The armature 10 includes an armature core 10b around which an armature coil 10c is wound, an armature shaft 10a press-fitted to a center hole of the armature core 10b. Coil ends of the armature coil 10c bent on a rear axial end surface of the armature core 10b are utilized as the commutator 9. Brushes 11 slidably contact on the surface of the commutator 9 in the axial direction of the armature 10. The output shaft 3 is coaxially disposed with the armature shaft 10a at the front side of the starter 1 and is rotatably supported by a bearing 14 held in the front housing 12 and another bearing 15 held in a center case 16 that is disposed inside the front housing 12. A known type of a planetary gear speed reduction mechanism and an one-way clutch are interposed between the armature shaft 10a and the output shaft 3. The planetary gear speed reduction mechanism is composed of a sun gear formed at the front end of the armature shaft 10a and planetary gears 17 engaging with the sun gear. Each planetary gear 17 rotates around a gear shaft 17a, and all the planetary gears orbit around the sun gear. The one-way clutch is composed of a clutch outer 18 to which the gear shafts 17a are fixed, a clutch inner 19 formed integrally with the output shaft 3, and clutch rollers 20 disposed between the clutch outer 18 and the clutch inner 19. The clutch outer 18 rotates together with the orbital rotation of the planetary gears 17, and transmits a rotational torque of the armature 10 to the clutch inner 19 via the rollers 20. Thus, the rotation of the armature 10, speed of which is reduced by the planetary gear reduction mechanism, is transmitted to the output shaft 3. Transmission of the rotational torque from the output shaft 3 to the armature 10 is interrupted by the one-way clutch. The pinion unit 4 is composed of a pinion gear 4b and a flange 22 formed at a rear side of the pinion gear 4b. The flange 22 has a diameter larger than that of the pinion gear 4b, and a series of depressions 22a are formed on the outer periphery of the flange 22. A female spline 4a is formed in the inner bore of the pinion unit 4, and a male spline 3a is formed on the outer periphery of the output shaft 3. Both splines are coupled to each other, thereby the pinion unit 4 is spline-coupled to the output shaft 3 so that the pinion unit 4 slidably moves on the output shaft 3 in the axial direction while the output shaft 3 rotates. The pinion unit 4 is biased toward the rear side by a spring 21 disposed between the front end of the front housing 12 and the pinion unit 4. A restricting member 23, which restricts movement of the pinion unit 4 toward the rear side after the pinion gear 4b engages with a ring gear R of the engine, is disposed at a rear side of the flange 22. The restricting member 23 functions in cooperation with the pinion-rotation-restricting member 5 in a manner described later in detail. A shutter 24 for closing or opening a front opening of the front housing 12 is disposed at the front side of the pinion unit 4 and is pushed toward the front axial end of the pinion unit 4 by the spring 21. A crank bar 6 is made of a round metal rod, and both ends are bent in a crank shape. Thus, the crank bar 6 is composed of a straight portion 6c, a coupling end 6a and an operating end 6b. The coupling end 6a is coupled to a hook 26 formed on a plunger 25 of the magnetic switch 7. The operating end 6b is connected to the pinion-rotation-restricting member 5. The straight portion 6c extends in the axial direction through a space between permanent magnets 8b connected to the inner bore of the yoke 8a and is rotatably supported by a pair of bearings (not shown). When the plunger 25 moves upward, the crank bar 6 is rotated and thereby the operating end 6b pushes up the rotation-restricting-member 5. The rotation-restricting-member 5 engages with the depressions 22a formed on the flange 22 of the pinion unit 4. Thus, the rotation of the pinion unit 4 is restricted before the electric motor 2 rotates. The structure of the magnetic switch 7 will be described with reference to FIGS. 1 and 4. The magnetic switch 7 is composed of a coil 29 to which electric current is supplied from a battery 28, a plunger 25 disposed inside the coil 29 and driven by the magnetic force generated in the coil 29, a return spring 30 that biases the plunger 25 downward, and other associated components. The magnetic switch 7 is disposed at the rear side of the electric motor 2 so that the plunger 25 is positioned perpendicularly to the axial direction of the armature 10 and is contained in the rear cover 13. The magnetic switch 7 is connected to a mounting base 31 that is fixedly positioned in the rear cover 13. As shown in FIG. 4, the switch “A” is composed of a stationary contact 33 connected to the battery 28 via a battery cable 32 and a movable contact 35 connected to the brush (plus side) 11 via a brush lead wire 34. As shown in FIG. 1, the stationary contact 33 is integrally formed with a terminal bolt 36 and positioned inside the end cover 13. The battery cable 32 is connected to the terminal bolt 36 extending from the end cover 13. As shown in FIG. 1, the movable contact 35 is held by a holder 37 made of insulating resin together with a spring 38 (refer to FIG. 2) and is positioned close to the plus side brush 11. The movable contact 35 held by the holder 37 faces the stationary contact 33. The holder 37 is mechanically connected to the plunger 25 of the magnetic switch 7 via a holder stay 39 and moves together with the plunger 25. The movable contact 35 is held by the holder 37 as shown in FIG. 2. That is, the movable contact 35 is biased against a pair of claws 37b by the spring 38 disposed between the movable contact 35 and a base plate 37a of the holder 37. The spring 38 gives a pushing force to the movable contact 35 when the movable contact 35 contacts the stationary contact 33, thereby a proper contact pressure is given between the stationary contact 33 and the movable contact 35. As shown in FIG. 3, one end of the brush lead wire 34 is mechanically and electrically connected to the plus side brush 11. The other end of the brush lead wire 34 is directly connected to a rear surface of the movable contact 35 (a front surface of the movable contact 35 contacts the stationary contact 33) by soft-soldering. The soft-soldering is performed at a low temperature such as 300° C. Operation of the starter 1 described above will be described below. Upon closing the key-switch 27, electric current is supplied to the coil 29 of the magnetic switch 7. The plunger 25 disposed inside the coil 29 is moved upward (in FIG. 1) by the magnetic force generated in the coil 29. The coupling end 6a of the crank bar 6 connected to the plunger 25 moves upward, and thereby the pinion-rotation-restricting member 5 connected to the operating end 6b of the crank bar 6 also moves upward. The pinion-rotation-restricting member 5 engages with the depression 22a formed on the flange 22. Thus, rotation of the pinion unit 4 is restricted. On the other hand, according to the upward movement of the plunger 25, the movable contact 35 contacts the stationary contact 33 (the switch “A” is closed). Electric current is supplied to the electric motor 2 from the battery 28, and thereby the electric motor 2 rotates. The rotation of the electric motor 2 is transmitted to the output shaft 3 via the planetary gear speed reduction mechanism and the one-way clutch, the rotational speed of the electric motor 2 being reduced by the planetary gear speed reduction mechanism. When the output shaft 3 rotates, the pinion unit 4 that is spline-coupled to the output shaft 3 is pushed forward (toward the ring gear R of the engine) on the output shaft 3, because the rotation of the pinion unit 4 is restricted. Thus, the pinion gear 4b engages with the ring gear R. When the pinion gear 4b engages with the ring gear R, the restriction of its rotation is released and a backward movement of the pinion unit 4 is restricted by the restricting member 23, because the pinion-rotation-restricting member 5 is separated from the depression 22a of the flange 22 and is positioned at the rear side of the restricting member 23. The pinion gear 4b engaging with the ring gear R is rotated by the output shaft 3, and thus, the engine is cranked up. After the engine is cranked up, the key-switch 27 is opened. The magnetic force generated in the coil 29 disappears, and the plunger 25 returns to its original position (the position shown in FIG. 1) due to the biasing force of the return spring 30. According to this downward movement of the plunger 25, the crank bar 6 is rotated and the pinion-rotation-restricting member 5 returns to its original position. The pinion unit 4 moves backward to its original position due to the biasing force of the spring 21, because the pinion-rotation-restricting member 5 comes out of the rear surface of the restricting member 5 and allows the restricting member 5 to move backward. Power supply to the electric motor 2 is shut off in response to opening of the switch “A”, which is caused by the downward movement of the plunger 25. Advantages of the present invention are as follows. The magnetic switch 7 is contained in the end cover 13, and the plunger 25 is positioned perpendicularly to the armature shaft 10a. Therefore, the movable contact 35 connected to the plunger 25 can be positioned close to the brush 11 that silidably contacts the commutator 9. A large amount of heat generated on the commutator surface can be easily conducted to the connection C (refer to FIG. 3) formed by the soft-soldering between the movable contact 35 and the brush lead wire 34 through the brush lead wire 34. The commutator surface is the position where the temperature in the starter 1 becomes the highest, and the connection C is located in the space enclosed by the end cover 13. Therefore, the temperature of connection C becomes nearly the highest in the starter 1. Accordingly, when the temperature in the starter 1 becomes unusually high for some reason, the connection C melts away quickly and shuts off the power supply to the electric motor 2 before other portions of the starter 1 are damaged by the heat. Since the connection C is made by soft-soldering, electric resistance at the connection C can be kept low. In a conventional fuse that is formed by partially decreasing a cross-sectional area of a power supply circuit, the electric resistance becomes high, and the output of the starter is sacrificed. The movable contact 35 is pulled by the brush lead wire 34 when the movable contact 35 is in contact with the stationary contact 33. Therefore, the brush lead wire 34 is easily and quickly separated from the movable contact 35 without providing a resilient member for separating both (as done in the conventional starter described above) when the connection C melts away due to a high temperature. If the brush lead wire 34 is welded to the movable contact 53 at a high temperature such as 500° C., the brush lead wire 34 may be deteriorated by heat. According to the present invention, however, the connection C is formed by soft-soldering at a low temperature about 300° C. Therefore, the brush lead wire 34 is not deteriorated and is able to be used for a long time. A second embodiment of the present invention will be described with reference to FIGS. 5 and 6. In this embodiment, an auxiliary switch “B” is connected in parallel to the switch “A”. The auxiliary switch B is composed of an auxiliary stationary contact 40 electrically connected to the stationary contact 33 and an auxiliary movable contact 41 electrically connected to the movable contact 35. The auxiliary stationary contact 40 is made of a material having resistance higher than that of the stationary contact 33, such as carbon, and is electrically connected to the auxiliary contact 33 through a metal plate 42 that is fixed to the end cover 13 together with the terminal bolt 36. Alternatively, the auxiliary stationary contact 40 may be made of a material such as copper and a member having a higher resistance may be connected between the auxiliary stationary contact 40 and the stationary contact 33. The auxiliary movable contact 41 is made of a resilient metal plate 43 (e.g., copper plate) formed in a U-shape, and electrically connected to the movable contact 35. The auxiliary movable contact 41 is held by the holder 37 together with the movable contact 35. The resilient metal plate 43 also functions as a contact spring that provides a contacting force between the auxiliary stationary contact 40 and the auxiliary movable contact 41 when they are closed. A distance between the auxiliary stationary contact 40 and the auxiliary movable contact 41 is made smaller than a distance between the stationary contact 33 and the movable contact 35, so that the auxiliary switch B closes before the main switch A closes. The auxiliary switch B is positioned very close to the switch A. Operation of the second embodiment will be briefly described. The process of restricting rotation of the pinion unit 4 is the same as that of the first embodiment. After the pinion rotation is restricted, the auxiliary switch B is closed, and a small amount of current (because the current is restricted by the resistance in the auxiliary switch B) is supplied to the electric motor 2. While the output shaft 3 is driven by the electric motor 2 at a low speed, the pinion unit 4 is pushed forward slowly. The pinion gear 4b slowly engages with the ring gear R. Because the pinion gear 4b is slowly pushed forward, a collision impact between the pinion gear 4b and the ring gear R is alleviated and the engagement between the pinion gear 4b and the ring gear R is smoothly established. Until the engagement between the pinion gear 4b and the ring gear R is established, the switch A is not closed because the upward movement of the plunger 25 is hindered by the crank bar 6 coupled to the depression 22a of the flange 22. After the pinion gear 4b engages with the ring gear R, the plunger 25 moves further upward and the switch A is closed. A full amount of current is supplied to the electric motor 2, and the electric motor 2 rotates at a full speed thereby to crank up the engine. The connection C (refer to FIG. 3) between the brush lead wire 34 and the movable contact 35 in this embodiment is formed by soft-soldering in the same manner as in the first embodiment. Therefore, the connection C is quickly opened before other portions in the starter 1 are damaged by unusually high temperature. Thus, the power supply to the electric motor 2 is quickly shut off, and thereby the starter 1 is protected form overheating. In this embodiment, the auxiliary switch B is positioned close to the switch A, and heat generated in the auxiliary switch B is transferred to the connection C in addition to a large amount of heat conducted to the connection C through the brush lead wire 34. Therefore, the connection C is further quickly opened when the temperature becomes unusually high. While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form and detail may be made therein without departing from the scope of the invention as defined in the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a starter for cranking an internal combustion engine, and more particularly to a starter that includes a structure for preventing overheating. 2. Description of Related Art It has been becoming a serious problem that the earth is being warmed up by carbon dioxide contained in the atmosphere. To cope with this problem by reducing fuel consumption in an automobile vehicle, great efforts are being made in downsizing automotive parts and components. In a starter motor for cranking an engine, its size and weight have been considerably reduced. On the other hand, the downsizing brings a problem of overheating. To overcome the overheating problem, various measures, such as improving heat-durability of materials used in the starter, have been taken. Such measures, however, have not been sufficiently effective to overcome the overheating problem. If it is difficult to start an engine, or if a key-switch does not return to its original position, a large amount of current, such as several hundreds amperes, continues to flow through a starter for a long time. If this happens, the starter overheats and a further serious problem may follow. If a switch for supplying current to the starter is not opened due to its malfunction after the engine is successfully cranked up, several tens amperes may be continuously supplied to the starter. In this case, the starter continues to rotate at a high speed. Not only the starter is overheated but also commutator segments may be separated from a commutator surface by a high centrifugal force applied thereto. This may results in a complete loss of the starter. Various proposals have been made as to ways and methods to shut off the current supply to the starter under such accidental situations mentioned above. For example, JP-A-10-66311 and WO-02/16763A1 propose to provide a fuse that melts away when the starter is overheated. Such a fuse may be provided in a main circuit for supplying current to the starter or in a pig tail connecting brushes. The fuse may be formed by reducing a cross-sectional area of a certain portion of the circuit. On the other hand, DE-10044081A1 and JP-A-59-185869 propose to form a solder-connection at certain position of a main circuit for supplying current to the starter, so that current supply is shut down by deformation or melting of the solder-connection when the starter is overheated. The overheating problem, however, has not been sufficiently solved by those proposals. When the proposed fuse is used in the starter circuit, the fuse is blown away at a certain amount of current peculiar to that fuse. The amount of current flowing through the starter under no load condition is several tens amperes, while the amount of current is as high as several hundreds amperes when the starter is continuously operated without succeeding in cranking up the engine. Therefore, it is difficult to shut down the current in various levels with a single fuse. That is, if the fuse is designed to be blown at several hundreds of amperes, it is successfully blown by a high level of current, but it is not blown by a low current such as several tens of amperes. On the other hand, if the fuse is designed to be blown by a low level current, there is a possibility that the current supply is unnecessary shut down. In addition, it is unavoidable that a resistance in the circuit is increased by such a fuse, resulting in decrease in the starter output. Because a large amount of current usually flows in the starter, the starter output is considerably reduced if there is an increase in resistance even in a small amount. To compensate such output decrease, the starter has to be made larger, which is contradictory to the downsizing. In the technology of forming the solder-connection in the main circuit (proposed by DE-10044081A1 and JP-A-59-185869), it is expected that the solder-connection is deformed or disconnected without fail before components of the starter are damaged by overheating. For this purpose, the solder-connection has to be formed at a position where temperature is the highest and at a position that is closest to a power source such as a battery. Usually, the position where the temperature is the highest is a commutator surface which brushes slidably contact. However, it is difficult to form the solder-connection at a place where constant heat conduction from the commutator surface can be expected. JP-A-59-185869 shows a solder-connection formed between a terminal bolt of a magnetic switch and a stationary contact. It further shows a resilient member for forcibly separating the circuit when the solder-connection melts away at a high temperature. DE-10044081A1 also proposes a similar resilient member for separating two contacts between which a solder-connection is formed. However, since the solder-connection is positioned, in both proposals, at a place far from a heat generating point, there is a possibility that an electric motor in the starter is damaged before the solder-connection shuts off the current supply. Further, since the resilient member is used in both proposals, a larger number of parts is required, resulting in a higher manufacturing cost. Further, DE-10044081 proposes to connect brushes and pig tails with solder. However, since the solder-connections are located far from the power source, it is difficult to shut off the current supply before other parts are damaged by heat. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide an improved compact starter in which power supply is shut off without fail when the starter is about to overheat. The starter for cranking an internal combustion engine is composed of an electric motor, an output shaft driven by the electric motor, a pinion gear spline-coupled to the output shaft, and a magnetic switch for engaging the pinion gear with a ring gear of the engine and for supplying electric current to the electric motor. The electric motor includes a stator for providing a magnetic field and an armature rotating in the stator. The armature has a commutator with which brushes are slidably in contact to thereby supply electric current to the armature from an on-board battery. In the power supply circuit, a switch having a stationary contact and a movable contact driven by a plunger of the magnetic switch is disposed. The movable contact is connected to the brush through a brush lead wire. On end of the brush lead wire is mechanically and electrically connected to the brush and the other end of the brush lead wire is directly connected to the movable contact by soft-soldering which is formed at a low temperature such as 300° C. The connection formed by the soft-soldering is positioned in the vicinity of the commutator which generates a large amount of heat. The magnetic switch and the switch are enclosed in an end cover not to be cooled, so that the connection formed by the soft-soldering reaches a high temperature when the starter is about to overheat. Further, the brush lead wire is so made that a certain pulling force is applied to the movable contact when the switch is closed. Since the connection formed by the soft-soldering is located close to the commutator and heat generated on the commutator surface is easily conducted to the connection through the brush lead wire, the temperature of the connection easily becomes high under unusual situations, e.g., when current is continuously supplied to the electric motor for some reasons. Further, since the connection is enclosed by the end cover, the heat of the connection is not easily dissipated. Therefore, the connection formed by the soft-soldering melts away before other components of the starter are damaged by heat. In addition, since there is a force pulling away the brush lead wire from the connection, the brush lead wire is quickly separated from the movable contact when the connection melts away. Therefore, it is not necessary to provide a resilient member for separating the lead wire from the movable contact. An auxiliary switch may be connected in parallel to the switch in the power supply circuit. In this case, the auxiliary switch is adapted to close before the switch is closed and to supply a limited amount of current to the electric motor, so that a process of establishing engagement between the pinion gear and the ring gear is slowly performed. The present invention is advantageously applied to a starter, a pinion gear of which is engaged with a ring gear of the engine while restricting rotation of the pinion gear. Other objects and features of the present invention will become more readily apparent from a better understanding of the preferred embodiments described below with reference to the following drawings. | 20040709 | 20060711 | 20050310 | 94698.0 | 0 | CASTRO, ARNOLD | STARTER HAVING STRUCTURE FOR PREVENTING OVERHEATING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,886,558 | ACCEPTED | Solid state fluid level sensor | A sensor system for sensing liquid level in a bilge, for use in automatic bilge pump actuation. First and second field effect sensors are potted or sealed within a container or the bilge wall and are aligned in a vertical array and each comprise a substantially planar pattern of “electrodes” or conductive traces disposed on a printed circuit board (PCB) along with integrated circuits used to create a loop or arc-shaped electric field. As bilge liquid rises to the proximity or level of the field effect sensors, a change in the arc-shaped electric field is sensed and, in response, a bilge pump is automatically actuated to pump liquid out of the bilge. Optionally, the pump control can be programmed by use of a microprocessor to permit control of on-off timing and prevent undesirable effects of “sloshing.” | 1. A fluid level sensor apparatus for detecting a moving fluid level and capable of activating a controlled device, said fluid level sensor apparatus comprising: a fluid-proof barrier of substantially uniform thickness having first and second opposite surfaces, wherein said first barrier surface is exposed to the fluid; a dielectric substrate of substantially uniform thickness having first and second opposite surfaces, wherein said substrate is proximate said barrier second surface; a first thin, conductive electrode pad disposed on said substrate in a closed, continuous geometric form having an area which affords substantial coverage by fluid contact with said barrier; a second thin, conductive electrode disposed on said substrate in a spaced, coplanar and substantially surrounding relationship to said first electrode pad; and an active electrical component disposed on said substrate proximate said first and second electrodes and electrically coupled to said first and second electrodes, such that fluid contact with said barrier activates the controlled device. 2. The fluid level sensor apparatus of claim 1, further comprising: a fluid-proof housing enclosing a cavity proximate said fluid proof barrier; and wherein said substrate is sealed within said cavity. 3. The fluid level sensor apparatus of claim 2 wherein said substrate is overmolded within said housing cavity. 4. The fluid level sensor apparatus of claim 3 wherein said electric field has an arc-shaped path originating at said second electrode and terminating at said first electrode. 5. The fluid level sensor apparatus of claim 4, wherein said fluid level sensor generates a detection signal indicating the status of said fluid level sensor. 6. The fluid level sensor apparatus of claim 5, wherein the level of said detection signal is altered when said fluid level contacts said barrier first surface and approaches said substrate. 7. The fluid level sensor apparatus of claim 1 wherein said substrate is glass. 8. The fluid level sensor apparatus of claim 1 wherein said substrate is plastic. 9. The fluid level sensor apparatus of claim 1 wherein said substrate is made from a fiberglass reinforced epoxy resin. 10. The fluid level sensor apparatus of claim 1 wherein a channel is located between said first and second electrodes, said channel having a generally uniform width. 11. The fluid level sensor apparatus of claim 1 wherein a plurality of said fluid level sensor electrodes are disposed on said first surface of said substrate. 12. The fluid level sensor apparatus of claim 1 wherein a plurality of said fluid level sensor electrodes are disposed on said substrate and arranged in a vertical array. 13. A low impedance fluid level sensor apparatus for detecting contact by a fluid and capable of activating a controlled device, said fluid level sensor apparatus comprising: a dielectric carrier; a first thin, conductive electrode pad disposed on said carrier in a closed, continuous geometric form having an area which affords substantial coverage by a region of fluid contact; a second thin, conductive electrode disposed on said carrier in a spaced and substantially surrounding relationship to said first electrode; an active electrical component disposed on said carrier proximate said first and second electrodes and electrically coupled to said first and second electrodes; and a dielectric substrate having first and second opposite surfaces, said dielectric carrier disposed on said first surface of said dielectric substrate, such that fluid contact of said substrate activates the controlled device. 14. The apparatus of claim 13 wherein said first surface of said substrate is a non-fluid touching surface and said second surface of said substrate is a fluid touching surface. 15. A low impedance fluid proximity sensor apparatus for detecting fluid contact and capable of activating a controlled device, said fluid proximity sensor apparatus comprising: a dielectric substrate having first and second opposite surfaces; a first thin, conductive electrode pad disposed on said substrate in a closed, continuous geometric form having an area which affords substantial coverage by an area of fluid contact; a second thin, conductive electrode disposed on said substrate in a spaced, coplanar and substantially surrounding relationship to said first electrode pad; and an active device disposed on said first surface of said substrate proximate said first and second electrodes and electrically coupled to said first and second electrodes, such that fluid contact with said substrate activates the controlled device. 16. The fluid proximity sensor apparatus of claim 15 wherein said active device is an ASIC configured to energize said electrodes with an oscillator signal. 17. The fluid proximity sensor apparatus of claim 16 further including at least one gain tuning resistor disposed on said substrate and electrically coupled between said ASIC and one of first and second electrodes. 18. The fluid proximity sensor apparatus of claim 17, wherein a plurality of said fluid proximity sensors are disposed on said substrate. 19. The fluid proximity sensor apparatus of claim 17 wherein said fluid proximity sensor ASIC generates a detection signal in response to a rising fluid level. 20. A plurality of fluid sensing pads for detecting fluid contact and capable of activating a controlled device, each fluid sensing pad comprising: a dielectric carrier; a first thin, conductive electrode pad having a peripheral edge and disposed on said carrier in a closed, continuous geometric form having an area which affords substantial coverage by a fluid contact area; a second thin, conductive electrode disposed on said carrier in a spaced relationship to said first electrode, said second electrode surrounding said first electrode on peripheral edges having an adjacent fluid sensing pad; and a dielectric substrate having first and second opposite surfaces, said carrier disposed on said first surface of said substrate, such that fluid contact with said substrate activates the controlled device. 21. A fluid proximity sensor for detecting a moving fluid and capable of generating a fluid presence detected signal or activating a controlled device, said fluid proximity sensor apparatus comprising: a fluid-proof dielectric substrate of substantially uniform thickness having first and second opposite surfaces; a first thin, conductive electrode pad disposed on said first surface of said substrate in a closed, continuous geometric form having an area which affords substantial coverage by fluid contact with said substrate second surface; a second thin, conductive electrode disposed on said first surface of said substrate in a spaced, coplanar and substantially surrounding relationship to said first electrode pad; and an active electrical component disposed on said substrate proximate said first and second electrodes and electrically coupled to said first and second electrodes, such that fluid contact with said substrate second surface activates the controlled device. 22. The fluid proximity sensor of claim 21, wherein said first thin, conductive electrode pad disposed on said first surface of said substrate comprises a balanced pad electrode having an area that is substantially equal in area with the area of said second conductive electrode. 23. The fluid proximity sensor of claim 22, wherein said balanced pad electrode comprises a substantially planar electrode having a plurality of conductive traces connected at an end to other conductive traces and separated by segments of non-conductive dielectric material. 24. The fluid proximity sensor of claim 23, wherein said balanced pad electrode has a substantially rectangular conductive perimeter. 25. The fluid proximity sensor of claim 23, further comprising a substantially planar conductive ground ring disposed on said substrate and encircling said second electrode. 26. A method of operating a bilge pump, comprising the steps of: a) positioning within a bilge a sealed housing having therein at least a first field effect sensor; b)generating an electromagnetic field with the sensor; and c) sensing the presence of fluid proximate the sensor by detecting variations in the electromagnetic field. 27. The method of claim 26, further including the step of: d) operating the bilge pump when a fluid is detected. 28. The method of claim 27, further including the step of: e) stopping operation of the bilge pump when the fluid is no longer detected. 29. The method of claim 27, further including the step of: e) stopping operation of the bilge pump when the fluid level is determined to be at a selected lower level. 30. The method of claim 26, further including the steps of: d) starting a timer and measuring the duration of the interval for which fluid is present, and, if fluid is present for an interval indicating that the sensed condition is not a result of sloshing fluid; and e) operating the bilge pump. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to sensors for detecting the presence of a fluid, automatic systems for actuating pumps in response to detecting a fluid level and sensors mounted in the bottom of a boat bilge tank activating a bilge pump when the bilge fluid level reaches a preset distance above the bottom of the bilge tank. 2. Discussion of the Prior Art In the past, bilge pumps have been activated manually or by mechanical float type switches with mercury or point contacts to complete an electrical circuit activating a pump. Pressure switches have also been used. These prior art switches worked adequately when initially installed. Over time, however, bilge debris and other sources of contamination often prevented the mechanical components from moving as intended, causing switch failure. In addition, prior art bilge pump activation switches typically wore out several times during the life of a boat and, being located in a boat's nether regions, were difficult to access for repair and replacement. Many fluid level or fluid proximity detectors of the prior art employed electrical switches actuated when a conductor, such as a body of water, moved into close proximity to the detector or sensor. U.S. Pat. Nos. 3,588,859; 3,665,300; 4,800,755 and 4,875,497 disclose such detectors. U.S. Pat. No. 5,017,909, discloses a proximity detector used as a liquid level detector for receptacles in vehicles. Other applications for liquid level detectors included bilge-pumping systems for ships. A bilge pumping system must be activated before the accumulated water reaches an excessive level. Prior art mechanisms for detection of an excessive bilge water level employed mechanical floatation systems, causing a switch to be actuated whenever the water reached such an undesired level. Bilge fluid or water eventually renders mechanical level sensing systems inoperative in part because bilge fluid can contain many forms of corrosive waste. Replacing failed parts a bilge level sensing system can be very expensive and troublesome, since a skilled technician must enter the bilge to perform the work. Many electronic proximity detection systems have been proposed in searching for a solution to this messy, expensive problem. By way of example, Smith et al (U.S. Pat. No. 4,881,873) discloses a capacitive level sensor for a bilge pump including a sensor plate 40 positioned in a bilge at a position selected for pump actuation. The bilge water is sensed as a dielectric, in a manner of speaking, and so the sensor is susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the area around the sensor, and sloshing bilge water is likely to cause the bilge control to actuate when the bilge level does not require pumping. Gibb (U.S. Pat. No. 5,287,086) also discloses a capacitive level sensor for a bilge pump including a capacitive sensor plate 79 positioned in a bilge at a position selected for pump actuation. The sensor is contained within a sealed housing 32 to keep bilge water away from the sensor and other circuitry. Here again, bilge water is sensed as a dielectric, in a manner of speaking, and so the sensor is susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the area around the sensor, and sloshing bilge water is likely to cause the bilge control to actuate when the bilge level does not require pumping. Santiago (U.S. Pat. No. 4,766,329) discloses a solid-state two level sensor for a bilge pump including a high water level probe and a low water level probe, both positioned in a bilge at positions selected for pump actuation. The probes are in contact with the bilge water, and so the probe sensors are susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the probes. Farr (U.S. Pat. No. 5,238,369) discloses a system for liquid level control including upper and lower capacitive level sensors 10, 18 having positions selected for pump actuation. This reference is silent on the need to keep bilge water away from the sensors, but the bilge water is sensed as a dielectric, in a manner of speaking, and so the sensor is susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the area around the sensors. The applicant has licensed a Field Effect sensor patent to Caldwell (U.S. Pat. No. 5,594,222) on a “touch sensor” used to detect whether a user presses a virtual button; this sensor is referred to as a “touch sensor.” While the patent discloses the electromagnetic properties of Field Effect “touch” sensing, it is silent on how such technology might be employed in a sensor system for detecting a fluid/air interface or for automated bilge pump actuation. There is a need, therefore, for a system for sensing liquid level and liquid level control that overcomes the problems with prior art sensors and systems, permitting installation of a reliable, inexpensive fluid level sensing system which is unlikely to require maintenance or cleaning in the bilge. It would be highly desirable to have a new and improved proximity detection system which is highly reliable and relatively inexpensive to manufacture. Such a proximity detection system should be highly sensitive and possess a wide range of applications. SUMMARY OF THE INVENTION The fluid level control and sensor system of the present invention comprises a fluid tight housing or container and a circuit board with electrodes and interconnect patterns assembled with components to create an electric field having arc shaped patterns and sense changes using the field effect principle. The housing or container holds first and second electrode patterns in a vertical orientation and has ribs on the housing's sides to allow debris found in a bilge to slough off. By careful selection of materials, the container can resist biological attack (e.g., fungus or algae) and prevent fouling from other materials that might stick to the container otherwise. In the vertical position, gravity also helps to allow the anticipated contamination to slough off. The field effect is described elsewhere in U.S. Pat. No. 5,594,222 and others assigned to TouchSensor, LLC, which are typically used in large appliance applications for operator input. A similar principle is adapted to detect liquids in close proximity to the sensor, even when isolated from the liquid by a physical barrier, such as a tank wall or molded container. This technique rejects common mode contamination to the sensor and, through proper tuning of the device, allows the presence or absence of a liquid to be detected. Since this is a solid state device in close proximity to the detector and it is also low impedance, it is also very tolerant of electrical noise in the marine environment. The electrode design can have geometries ranging from parallel plates to concentric rings of various sizes and geometric shapes. The design of the electrodes is determined by the materials of construction, thickness, composition of the liquid and other considerations. Since the fluid level control and sensor system is submerged when active and passing current, an internal current switching device (e.g. a Field Effect Transistor (FET)) adapted to pass twenty amps is easily cooled. Electronics to support the sensor optionally include components allowing control of devices demanding twenty amps of current without the addition of a separate relay. Through current scalping and other techniques, the bilge pump control system of the present invention operates through two wires or can have a separate third wire to provide power. The fluid level control and sensor system can be implemented with or without a microprocessor. The bilge pump assembly consists of a housing, circuit board, components and wiring harness. In operation, the bilge pump sensor is installed in-line between the pump and a power supply. The circuit draws its own power from the power mains supply without activating the pump. Without bilge liquid present near the sensor electrodes, a sensing IC is at a first state, “off.” With a liquid present near the sensor electrodes, the IC changes state to “on” and the circuitry allows connection of power to the bilge pump. The pump is activated until the liquid level goes below the sensor electrodes. The sensing IC changes state to “off” and the power to the pump is interrupted, causing the pump to stop. The sequence is repeated whenever liquid comes in proximity to the sensor. An optional microprocessor allows control of on-off timing and other time management operations provide a stable pump operation without rapid changes from the “on” to the “off” state (e.g., due to an instability referred to as “sloshing”). Sloshing may vary in amplitude depending on the length of craft and bilge tank and the rocking motion of the craft. The bilge pump controller of the present invention includes a field effect sensor comprising an active, low impedance sensor on a dielectric substrate. The sensor has a first conductive electrode pad and a second conductive electrode which substantially surrounds the first electrode in a spaced apart relationship. The first electrode pad has a closed, continuous geometric shape and both electrodes are attached to the same surface of the substrate. An active electrical component is placed in close proximity to the electrodes. The sensor is used to replace conventional switches and is activated when bilge fluid or water contacts or comes into close proximity with the substrate. The sensor is used to turn an electric pump motor on or off. The field effect sensor design operates properly with liquids present on the substrate and in the presence of static electricity, and is well-suited for use in an environment where water, grease and other liquids are common, such as boat bilges or other sea-going applications. Electrodes are attached to the back surface of a substrate, opposite the front or “wet” surface, thereby preventing contact between the electrodes and the controlled fluid (e.g., bilge water). Since the sensor electrodes are not located on the wet surface of the substrate, the sensor is not damaged by scratching, cleaning solvents or any other contaminants which contact the substrate. The cost and complexity of the sensor is reduced since a relay or switch is not required. In the preferred form, an oscillator is electrically connected to the inner and outer electrodes through gain tuning resistors and delivers a square-wave like signal having a very steep slope on the trailing edge. The oscillator signal creates an arc shaped transverse electric field between the outer electrode and the center electrode. The electric field path is arc-shaped and extends through the substrate and past the front surface, projecting transversely to the plane of the substrate. The inner and outer electrode signals are applied as common mode signals to the inputs of a differential sensing circuit and when the difference in response between the inner and outer electrodes is great enough, the sensing circuit changes state (e.g., from high to low). The sensing circuit state is altered when the substrate is touched by the controlled fluid. In the preferred form, an active electrical component preferably configured as a surface mount application specific integrated circuit (ASIC), is located at each sensor. Preferably, the ASIC is connected to the center pad electrode and to the outer electrode of each sensor. The ASIC acts to amplify and buffer the detection signal at the sensor, thereby reducing the difference in signal level between individual sensors due to different lead lengths and lead routing paths. A plurality of sensors may be arranged on the substrate. The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings, wherein like reference numerals in the various figures are utilized to designate like components. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, in elevation, of a bilge fluid level control and sensor system, in accordance with the present invention. FIG. 2 is a partial cross section, in elevation, of the fluid level control and sensor system of FIG. 1, in accordance with the present invention. FIG. 3 is a back side view, in elevation, of the primary, back or dry surface of a printed wiring board assembly for the fluid level control and sensor system of FIGS. 1 and 2, in accordance with the present invention. FIG. 4 is a schematic diagram of the printed wiring board assembly for the fluid level control and sensor system of FIGS. 1, 2 and 3, in accordance with the present invention. FIG. 5 is a diagram illustrating a field effect fluid level sensor system showing the arc-shaped field passing through the fluid, in accordance with the present invention. FIG. 6 is a diagram drawn to scale and illustrating the component side layout of conductive traces on a printed circuit board including a balanced pad sensor electrode pattern. FIG. 7 is an edge view, in elevation, illustrating the conductive traces on the printed circuit board of FIG. 6 including the balanced pad sensor electrode pattern, as seen from the side. FIG. 8 is an edge view, in elevation, of an alternative two-sided embodiment illustrating the conductive traces on a printed circuit board including the balanced pad sensor electrode pattern, as seen from the side. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the exemplary embodiment illustrated in FIGS. 1-5, a bilge or fluid containment vessel 10 is bounded by a fluid tight wall or surface 18 and at times contains bilge water or some other fluid 12. The fluid level in the bilge rises and falls and the fluid level 14 is measurable over a selected dimension such as that shown by the vertical scale in FIG. 1. As the fluid level rises or falls, a fluid/air interface 16 can be sighted or measured along the fluid level scale 14. In the typical marine application, bilge 10 contains fluid 12 such as waste water or seawater that leaks through the hull or deck, and when the bilge fluid level 16 is excessively high (e.g., at a selected upper or trigger level 1 6H), fluid 12 must be pumped out, usually with an electrically powered pump (not shown) that is selectively energized when the excessively high fluid level 16H is detected. The fluid level is sensed while pumping progresses and the pump is turned off when the level of fluid 12 is low enough (e.g., at a selected lower or turn-off level 16L). As shown in FIGS. 1, 2 and 3, fluid level control and sensor system 20 of the present invention comprises a fluid tight housing or container 24 and a printed wiring board assembly 22 with electrodes 50, 52, 60 and 62 and interconnect patterns assembled with components to create an electric field having arc shaped patterns and sense changes using the “field effect” principle. Referring to FIGS. 4 and 5, the field effect is generated and changes in the field are sensed using patterns of conductive traces or electrodes 50, 52 which create arc shaped electric fields 70 projecting transversely and passing through substrate 30. When a rising fluid/air interface 16 is sensed, the arc shaped electric fields 70 pass through the fluid 12 rather than the air above the fluid/air interface. The operation of the sensor system 20 will be described in greater detail below. In the embodiment of FIG. 1, printed wiring board assembly 22 is disposed within a cavity 26 of housing or container 22 and, during assembly, is sealed inside to provide a fluid proof barrier of substantially uniform thickness. Printed wiring board or circuit board 30 is a dielectric planar substrate of substantially uniform thickness having a back side (shown in FIGS. 2 and 3) carrying the components and opposite a front side. The sensor system 20 is connected to a mains supply and an electric pump (not shown) via a two cable wire assembly 32 preferably comprising at least first and second sixteen gauge (16 AWG) wire segments. The electrical components in the sensor embodiment illustrated in FIGS. 2, 3 and 4 include a pre-programmed integrated circuit (IC) eight bit micro-controller also identified as U4, which is connected to and responsive to first and second touch switch ICs, 36, 37 also identified as U2 and U3, respectively. A sensor system power supply includes voltage regulator 38, also identified as U1, and the mains supply voltage is also controlled by a pair of diodes including series connected diode 46 and shunt connected zener diode 44 providing power to a voltage regulator 38. In the illustrated embodiment, the bilge water pump actuation and supply comes from a large switching N channel Field Effect Transistor (NFET) 42, the mains supply voltage (e.g., 12 VDC) is connected through connector J1 to the drain and the current, when switched on to actuate the pump, passes through the source and through connector J2 to the pump. As best seen in FIG. 3, a first sensor electrode pattern 49 includes a substantially rectangular upper center electrode pad 50 including a plurality of vertical conductive traces separated by approximately equal width sections of non-conductive PCB surface, where each conductive trace is connected at its upper and lower ends by a surrounding conductive trace, all connected to resistor R5. Upper center electrode pad 50 is not quite completely encircled by upper outer electrode 52 which is connected to upper touch sensor ASIC 36. Both inner pad 50 and outer electrode 52 are at least partly encircled by a perimeter of solid conductive trace material to provide a ground ring (not shown). The ground ring can be configured to influence sensitivity and directionality of outer electrode 52; if the ground ring is situated too closely to outer electrode 52, however, the sensor's differential mode is lost and the sensor behaves in a single ended fashion. A second sensor electrode pattern 59 is disposed in a vertically aligned orientation below the first sensor electrode pattern 49 and includes a substantially rectangular lower center electrode pad 60 including a plurality of vertical conductive traces separated by approximately equal width sections of non-conductive PCB surface, where each conductive trace is connected at its upper and lower ends by a surrounding conductive trace, all connected to resistor R7. Lower center electrode pad 60 is not quite completely encircled by lower outer electrode 62 which is connected to lower touch sensor ASIC 37. Both pad 60 and outer electrode 62 are also at least partially encircled by a second perimeter of solid conductive trace material to provide a second ground ring (not shown). In accordance with the present invention, the field effect principle is adapted to detect liquid 12 when in close proximity to sensor 20, even when isolated from the liquid by a physical barrier such as a tank wall or molded container (e.g., 24). This technique rejects common mode contamination to the sensor and, through proper tuning of the device, allows the presence or absence of liquid or fluid (e.g., bilge water 12) to be detected. Since the touch sensors ASICs 36, 37 are solid state devices in close proximity to the electrode pads and also of low impedance, they are also very tolerant of electrical noise in the marine environment. The electrode design can have geometries ranging from parallel plates to concentric rings of various sizes and geometric shapes. The design of the electrodes (e.g., 50, 52, 60 and 62) is determined by the materials of construction, thickness, composition of liquid 12 and other considerations, as will be appreciated by those with skill is the art. In the illustrated embodiment, the electronics supporting the sensor include components allowing control of devices (e.g., a pump) demanding 20 amps of current without the addition of a separate relay. Since fluid level control and sensor system 20 is submerged when active and passing current, heat sinking to the bilge fluid 12 allows an internal current switching device (e.g. NFET 42) and a twenty amp supply circuit to be easily cooled. Through current scalping and other techniques, the bilge pump control system 20 operates through two wires or can have a separate third wire (not shown) to provide power. Current scalping or scavenging utilizes the error output of Voltage regulator 38 as an input to microprocessor 34 which is programmed to turn off FET switch 42 for a short interval during which shunt storage capacitor C1 charges back to 12 volts. This current scalping method permits an “on-time” for FET switch 42 of at least 97%. Fluid level control and sensor system 20 can be implemented with or without a microprocessor (not shown). Housing or container 24 supports and protects first and second electrode patterns 49 and 59, in a vertical orientation and optionally has one or more external ribs transversely projecting vertically aligned elongated features 27 on the housing's sides to allow bilge debris to slough off or away from housing 24 as the fluid level falls during pumping. Housing 24 is preferably made of inert materials such as ABS, polypropylene or epoxy to resist biological attack (e.g., fungus or algae) and prevent fouling from other substances that might otherwise tend to stick to the housing or container sidewalls. In the vertical orientation or position shown in FIG. 1, gravity also helps to allow the anticipated contamination to slough off. In operation, the bilge pump sensor 20 is installed in-line between the pump and a power mains supply using wire assembly 32. The circuit draws its own power from the power mains supply through connector J1 without activating the pump. Without bilge liquid present near the sensor electrodes, each of the sensing ICs 36, 37 is at a first state, “off.” With liquid 12 present near the sensor electrodes, the sensing ICs 36, 37 change state to a second state, “on”, and the circuitry connects power through FET 42 to the bilge pump. The pump remains activated until the sensed liquid level 16 goes below the sensor electrodes 49 and 59. The sensing ICs 36, 37 then change state to “off” and the power to the pump is interrupted, causing the pump to stop. This sequence is repeated whenever the fluid surface 16 comes into proximity with the sensor system 20. An optional microprocessor allows control of on-off timing and other time management operations to provide a stable pump operation without rapid changes from the “on” to the “off” state (e.g., due to an instability referred to as “sloshing”). Sloshing may vary in amplitude depending on the length of craft and bilge tank and the rocking motion of the craft. The bilge pump controller or sensor system 20 of the present invention includes at least one field effect sensor comprising an active, low impedance sensor attached to only one side of dielectric substrate 30 and is used to replace conventional switches. The field effect sensor design operates properly with liquids present on the substrate and in the presence of static electricity, and is well-suited for use in a marine environment where water, grease and other liquids are common, such as boat bilges or other sea-going applications. As shown in FIG. 5, the sensor's printed wiring board assembly 22 may be molded or fabricated into the bilge sidewall 18 rather than being separately encapsulated in housing 24, with the front or “wet” side of the PC board 30 facing the interior of the bilge 10. Preferably, sensor electrode patterns 49, and 59 are attached to the back surface of PCB substrate 30. The back surface of the substrate is opposite the front or “wet” surface, thereby preventing contact of the electrodes by the controlled fluid (e.g., bilge water). Since the sensor electrodes are not located on the front surface of the substrate, the sensor is not damaged by scratching, cleaning solvents or any other contaminants which contact the front surface of the substrate. Furthermore, the cost and complexity of the sensor is reduced since a switch is not required. Preferably, an active electrical component, such as a surface ASIC (e.g., 36) is located at each sensor and connected between the center electrode (e.g., 50) and the outer electrode (e.g., 52) of each sensor. The ASIC acts to amplify and buffer the detection signal at the sensor, thereby reducing the difference in signal level between individual sensors due to different lead lengths and lead routing paths. The Integrated circuit connected to the field effect sensor electrodes is an active device and, in the illustrated embodiment, is preferably configured as ASIC operating in the manner described in U.S. Pat. No. 6,320,282, to Caldwell, the entire disclosure of which is incorporated herein by reference. As described above, a simple field effect cell has two electrodes (e.g., 50, 52), an ASIC (e.g., 36) and two gain tuning resistors (e.g., R5 and R6). The pin-out for the TS-100 ASIC of the invention is similar to that illustrated in FIG. 4 of the '282 patent, but the pin-outs vary slightly. The TS-100 ASIC is available from Touch Sensor, LLC. Specifically, for the TS-100 ASIC shown in this application, the input power (Vdd) connection is on pin 1, the ground connection is on Pin 2, the sensor signal output connection is on pin 3, the outer electrode resistor (e.g., R6) is connected to pin 4, the “oscillator out” connection is at pin 5 and the inner pad electrode resistor (e.g., R5) is connected to pin 6. Optionally, an ASIC can be configured to eliminate the need for gain tuning resistors R5 and R6 by making the gain tuning adjustments internal to the ASIC. The sensitivity of the field effect sensor or cell is adjusted by adjusting the values of gain tuning resistors R5 and R6. The sensor of the present invention can be adapted for use in a variety of applications and the gain resistors R5 and R6 can be changed to cause a desired voltage response. The sensor of the present invention is like other sensors in that the sensor's response to measured stimulus must be tuned or calibrated to avoid saturation (i.e., from gain/sensitivity set too high) and to avoid missed detections (i.e., from gain/sensitivity set too low). For most applications, a gain tuning resistor value which yields a sensor response in a linear region is preferred. The tuning or calibration method typically places the sensor assembly in the intended sensing environment and the circuit test points at the inputs to the decision circuit (e.g., points 90 and 91 as seen in FIG. 4 of Caldwell's '282 patent) are monitored as a function of resistance. The resistance value of the gain tuning resistors R5 and R6 are adjusted to provide an output in the mid-range of the sensor's linear response. While other electrode patterns are suitable for this bilge pump control application, the illustrated electrode patterns 49 and 59, as shown in 3, are each balanced. “Balanced” as used here, means that the conductive trace area of the inner electrode (e.g., center pad 50) is equal (or as equal as possible within PCB manufacturing tolerances) to the area of its corresponding outer electrode ring (e.g., outer electrode 52). The applicants have discovered that the illustrated balanced pad electrode design provides improved noise or electromagnetic interference (EMI) immunity and works exceptionally well for sensing the presence of a fluid such as water. The EMI immunity appears to stem from a common mode rejection of spurious noise or interference signals. This “common mode” rejection is attributable to the equal area of the center pad and the outer ring electrode, which appear to be affected by spurious noise or interference signals substantially equally, and so when one electrode's signal is subtracted from the other electrode's signal, the common noise/interference signals cancel one another. In the embodiment illustrated in FIG. 3, each balanced center pad is substantially rectangular having a horizontal extent of approximately twelve millimeters (mm) and a vertical extent of nine mm. As can be seen from FIG. 3, each center electrode pad (e.g., 50 and 60) include a plurality of vertical conductive traces (each approx. one mm in width) separated by approximately equal width sections of non-conductive PCB surface, where each conductive trace is connected at its upper and lower ends by a surrounding conductive trace material, all connected to a resistor (e.g., R5 for upper pad 50). Each center electrode pad (e.g., 50) is not quite completely encircled by upper outer electrode 52 which is approximately 1.5 mm in width and is connected to an ASIC (e.g., 36). An alternative electrode pattern embodiment is illustrated in FIGS. 6 and 7; FIG. 6 is a diagram drawn to scale and illustrating the component side layout of conductive traces on a printed circuit board including a balanced pad sensor electrode pattern 69, and FIG. 7 is an edge view, in elevation, illustrating the conductive traces of balanced pad sensor electrode pattern 69, as seen from the side of the PCB (e.g., such as PCB 30). As noted above, a balanced pad or electrode pattern has a conductive trace area for the inner electrode (e.g., center pad 70) that is equal (or as equal as possible within PCB manufacturing tolerances) to the area of its corresponding outer electrode ring (e.g., outer electrode 72). Both pad 70 and outer electrode 72 are also optionally encircled by a perimeter of solid conductive trace material to provide a ground ring 76. The optional ground ring 76 is useful for reducing the effects of the boat or bilge material on the operation of the sensor 20. When a ground ring 76 is included, sensor 20 may be installed in either a conductive (e.g. aluminum or steel) bilge or a dielectric (e.g., fiberglass) bilge with negligible effects on sensor performance. An alternative electrode pattern embodiment is illustrated in FIG. 8, a diagram illustrating an edge view of a two-sided layout of conductive traces on a printed circuit board including a balanced pad sensor electrode pattern 79, as seen from the side of the PCB (e.g., such as PCB 30). As above, a balanced pad or electrode pattern has a conductive trace area for the inner electrode (e.g., center pad 80) carried on one side of the PCB that is equal (or as equal as possible within PCB manufacturing tolerances) to the area of its corresponding outer electrode ring (e.g., outer electrode 82) on the opposite side of PCB 30. Both pad 80 and outer electrode 82 are at least partially encircled by a perimeter of solid conductive trace material to provide a ground ring 86 which is spaced apart from outer electrode 82. An alternative embodiment with microprocessor control can be programmed to provide delays for pump turn-on and turn-off. The micro-controller has been programmed to read the lower level pad 60 and the upper level pad 50. Both pads must be activated for at least 256 consecutive reads before the bilge pump is turned on. The interval between reads is 0.0011 seconds, resulting in 0.286 seconds of total time of continuous reads with both pads active before turning on the pump. If at any time, either sensor is not active, the read is canceled and no pump enabling action is taken. -During periods when the pump is not active, the controller puts itself to sleep for 2.5 seconds and then wakes up and reads both upper and lower pads 50, 60. Thus, the time between water level readings is about 2.78 seconds. This pre-programmed algorithm would have a high probability of not turning on the pump if the water is merely sloshing around in bilge 10, but gives fairly quick response. This pre-programmed algorithm is preferably stored in a memory and operates in a manner similar to the principals of fuzzy logic. Other methods may be used to overcome “sloshing” Various electronic methods include using simple timing circuits like “one shots”, “pulse switching and timing circuits”, and “low pass filtering”. None of these would be as economical as using the single chip micro-computer incorporating the entire control function in simple circuit using a micro, however. A mechanical anti-sloshing control method includes configuring a plastic chamber or shield around the sensing area and allowing water to slowly flow in and out of the chamber and sensing area thereby preventing water level from changing very rapidly in the area of the senor. This damped flow method would not prevent sensors from switching on/off rapidly when the water level was at the very edge of activation, where slight movements of water or electrical noise would cause sensor oscillation. The mechanical anti-slosh chamber could be coupled with a simple electronic filter circuit such as a low pass and comparator, but this would require more plastic than the illustrated design. The mechanical method of slosh proofing could also be used in conjunction with our current micro-controller design. The anti-sloshing chamber may create problems if the water entry points were to get clogged due to dirt and/or debris. The illustrated micro controller solution results in the simplest, smallest, cheapest, lowest energy consumption result with maximum flexibility and reliability, and so is preferable to non-micro solutions or mechanical methods. Having described preferred embodiments of a new and improved method, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to sensors for detecting the presence of a fluid, automatic systems for actuating pumps in response to detecting a fluid level and sensors mounted in the bottom of a boat bilge tank activating a bilge pump when the bilge fluid level reaches a preset distance above the bottom of the bilge tank. 2. Discussion of the Prior Art In the past, bilge pumps have been activated manually or by mechanical float type switches with mercury or point contacts to complete an electrical circuit activating a pump. Pressure switches have also been used. These prior art switches worked adequately when initially installed. Over time, however, bilge debris and other sources of contamination often prevented the mechanical components from moving as intended, causing switch failure. In addition, prior art bilge pump activation switches typically wore out several times during the life of a boat and, being located in a boat's nether regions, were difficult to access for repair and replacement. Many fluid level or fluid proximity detectors of the prior art employed electrical switches actuated when a conductor, such as a body of water, moved into close proximity to the detector or sensor. U.S. Pat. Nos. 3,588,859; 3,665,300; 4,800,755 and 4,875,497 disclose such detectors. U.S. Pat. No. 5,017,909, discloses a proximity detector used as a liquid level detector for receptacles in vehicles. Other applications for liquid level detectors included bilge-pumping systems for ships. A bilge pumping system must be activated before the accumulated water reaches an excessive level. Prior art mechanisms for detection of an excessive bilge water level employed mechanical floatation systems, causing a switch to be actuated whenever the water reached such an undesired level. Bilge fluid or water eventually renders mechanical level sensing systems inoperative in part because bilge fluid can contain many forms of corrosive waste. Replacing failed parts a bilge level sensing system can be very expensive and troublesome, since a skilled technician must enter the bilge to perform the work. Many electronic proximity detection systems have been proposed in searching for a solution to this messy, expensive problem. By way of example, Smith et al (U.S. Pat. No. 4,881,873) discloses a capacitive level sensor for a bilge pump including a sensor plate 40 positioned in a bilge at a position selected for pump actuation. The bilge water is sensed as a dielectric, in a manner of speaking, and so the sensor is susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the area around the sensor, and sloshing bilge water is likely to cause the bilge control to actuate when the bilge level does not require pumping. Gibb (U.S. Pat. No. 5,287,086) also discloses a capacitive level sensor for a bilge pump including a capacitive sensor plate 79 positioned in a bilge at a position selected for pump actuation. The sensor is contained within a sealed housing 32 to keep bilge water away from the sensor and other circuitry. Here again, bilge water is sensed as a dielectric, in a manner of speaking, and so the sensor is susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the area around the sensor, and sloshing bilge water is likely to cause the bilge control to actuate when the bilge level does not require pumping. Santiago (U.S. Pat. No. 4,766,329) discloses a solid-state two level sensor for a bilge pump including a high water level probe and a low water level probe, both positioned in a bilge at positions selected for pump actuation. The probes are in contact with the bilge water, and so the probe sensors are susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the probes. Farr (U.S. Pat. No. 5,238,369) discloses a system for liquid level control including upper and lower capacitive level sensors 10 , 18 having positions selected for pump actuation. This reference is silent on the need to keep bilge water away from the sensors, but the bilge water is sensed as a dielectric, in a manner of speaking, and so the sensor is susceptible to false alarms or missed detections once the contamination accompanying bilge inflow has accumulated in the bilge and contaminated the area around the sensors. The applicant has licensed a Field Effect sensor patent to Caldwell (U.S. Pat. No. 5,594,222) on a “touch sensor” used to detect whether a user presses a virtual button; this sensor is referred to as a “touch sensor.” While the patent discloses the electromagnetic properties of Field Effect “touch” sensing, it is silent on how such technology might be employed in a sensor system for detecting a fluid/air interface or for automated bilge pump actuation. There is a need, therefore, for a system for sensing liquid level and liquid level control that overcomes the problems with prior art sensors and systems, permitting installation of a reliable, inexpensive fluid level sensing system which is unlikely to require maintenance or cleaning in the bilge. It would be highly desirable to have a new and improved proximity detection system which is highly reliable and relatively inexpensive to manufacture. Such a proximity detection system should be highly sensitive and possess a wide range of applications. | <SOH> SUMMARY OF THE INVENTION <EOH>The fluid level control and sensor system of the present invention comprises a fluid tight housing or container and a circuit board with electrodes and interconnect patterns assembled with components to create an electric field having arc shaped patterns and sense changes using the field effect principle. The housing or container holds first and second electrode patterns in a vertical orientation and has ribs on the housing's sides to allow debris found in a bilge to slough off. By careful selection of materials, the container can resist biological attack (e.g., fungus or algae) and prevent fouling from other materials that might stick to the container otherwise. In the vertical position, gravity also helps to allow the anticipated contamination to slough off. The field effect is described elsewhere in U.S. Pat. No. 5,594,222 and others assigned to TouchSensor, LLC, which are typically used in large appliance applications for operator input. A similar principle is adapted to detect liquids in close proximity to the sensor, even when isolated from the liquid by a physical barrier, such as a tank wall or molded container. This technique rejects common mode contamination to the sensor and, through proper tuning of the device, allows the presence or absence of a liquid to be detected. Since this is a solid state device in close proximity to the detector and it is also low impedance, it is also very tolerant of electrical noise in the marine environment. The electrode design can have geometries ranging from parallel plates to concentric rings of various sizes and geometric shapes. The design of the electrodes is determined by the materials of construction, thickness, composition of the liquid and other considerations. Since the fluid level control and sensor system is submerged when active and passing current, an internal current switching device (e.g. a Field Effect Transistor (FET)) adapted to pass twenty amps is easily cooled. Electronics to support the sensor optionally include components allowing control of devices demanding twenty amps of current without the addition of a separate relay. Through current scalping and other techniques, the bilge pump control system of the present invention operates through two wires or can have a separate third wire to provide power. The fluid level control and sensor system can be implemented with or without a microprocessor. The bilge pump assembly consists of a housing, circuit board, components and wiring harness. In operation, the bilge pump sensor is installed in-line between the pump and a power supply. The circuit draws its own power from the power mains supply without activating the pump. Without bilge liquid present near the sensor electrodes, a sensing IC is at a first state, “off.” With a liquid present near the sensor electrodes, the IC changes state to “on” and the circuitry allows connection of power to the bilge pump. The pump is activated until the liquid level goes below the sensor electrodes. The sensing IC changes state to “off” and the power to the pump is interrupted, causing the pump to stop. The sequence is repeated whenever liquid comes in proximity to the sensor. An optional microprocessor allows control of on-off timing and other time management operations provide a stable pump operation without rapid changes from the “on” to the “off” state (e.g., due to an instability referred to as “sloshing”). Sloshing may vary in amplitude depending on the length of craft and bilge tank and the rocking motion of the craft. The bilge pump controller of the present invention includes a field effect sensor comprising an active, low impedance sensor on a dielectric substrate. The sensor has a first conductive electrode pad and a second conductive electrode which substantially surrounds the first electrode in a spaced apart relationship. The first electrode pad has a closed, continuous geometric shape and both electrodes are attached to the same surface of the substrate. An active electrical component is placed in close proximity to the electrodes. The sensor is used to replace conventional switches and is activated when bilge fluid or water contacts or comes into close proximity with the substrate. The sensor is used to turn an electric pump motor on or off. The field effect sensor design operates properly with liquids present on the substrate and in the presence of static electricity, and is well-suited for use in an environment where water, grease and other liquids are common, such as boat bilges or other sea-going applications. Electrodes are attached to the back surface of a substrate, opposite the front or “wet” surface, thereby preventing contact between the electrodes and the controlled fluid (e.g., bilge water). Since the sensor electrodes are not located on the wet surface of the substrate, the sensor is not damaged by scratching, cleaning solvents or any other contaminants which contact the substrate. The cost and complexity of the sensor is reduced since a relay or switch is not required. In the preferred form, an oscillator is electrically connected to the inner and outer electrodes through gain tuning resistors and delivers a square-wave like signal having a very steep slope on the trailing edge. The oscillator signal creates an arc shaped transverse electric field between the outer electrode and the center electrode. The electric field path is arc-shaped and extends through the substrate and past the front surface, projecting transversely to the plane of the substrate. The inner and outer electrode signals are applied as common mode signals to the inputs of a differential sensing circuit and when the difference in response between the inner and outer electrodes is great enough, the sensing circuit changes state (e.g., from high to low). The sensing circuit state is altered when the substrate is touched by the controlled fluid. In the preferred form, an active electrical component preferably configured as a surface mount application specific integrated circuit (ASIC), is located at each sensor. Preferably, the ASIC is connected to the center pad electrode and to the outer electrode of each sensor. The ASIC acts to amplify and buffer the detection signal at the sensor, thereby reducing the difference in signal level between individual sensors due to different lead lengths and lead routing paths. A plurality of sensors may be arranged on the substrate. The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings, wherein like reference numerals in the various figures are utilized to designate like components. | 20040709 | 20080520 | 20060112 | 98760.0 | G01F2300 | 0 | SHAH, SAMIR M | SOLID STATE FLUID LEVEL SENSOR | UNDISCOUNTED | 0 | ACCEPTED | G01F | 2,004 |
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10,886,575 | ACCEPTED | Distributed bridging with synchronization forwarding databases | A network unit for use in a distributed bridging fabric has a multiplicity of user ports for the transmission of data frames to and from an external network and at least one fabric port for the transmission of frames between the network unit and another unit in the fabric. The network unit has a forwarding database for containing entries each including a media access control address, and a lookup engine organized for the insertion of an entry into the forwarding database when the network unit receives a data packet at a user port. The unit broadcasts via each fabric port of an “address added” message identifying a respective media access control address. The lookup engine also responds to such an “address added” message received from another unit to make a corresponding entry in the database and to annotate an entry to indicate activity of an address in response to an address which is already in the database. The network unit has an aging engine organized for the polling of entries in the database. The aging engine refreshes an entry for which the respective media access control address is annotated as active and is organized for the selective removal of inactive entries from the database. | 1. A network unit for use in a distributed bridging fabric, the network unit comprising: (a) a multiplicity of user ports for the transmission of data frames to and from an external network; (b) at least one fabric port for the transmission of frames between said network unit and another unit in the fabric; (c) a forwarding database for containing entries each including a media access control address; (d) a lookup engine organized for the insertion of an entry into said forwarding database on receipt of a data packet at a user port and for the broadcast via each fabric port of an “address added” message identifying a respective media access control address, said lookup engine responding to such an “address added” message received from another unit to make a corresponding entry in the database; and to annotate an entry to indicate activity of an address in response to an address which is already in said database; and (e) an aging engine organized for the polling of entries in the database, said aging engine refreshing an entry for which the respective media access control address is annotated as active and organized for the selective removal of inactive entries from the database. 2. A network unit as in claim 1 wherein each entry includes a source field indicating whether the respective media access control address was derived from a packet for which the network unit or another unit was the source unit for that packet within the fabric. 3. A network unit as in claim 2 wherein the source field identifies said source unit. 4. A network unit as in claim 2 wherein said aging engine is organized to determine whether an address is active, to remove entries for which the corresponding media access control address is inactive and to cause the broadcast to other units in the fabric of an “address active” message in respect of active addresses for which the network unit was the source unit within the fabric for that address. 5. A network unit as in claim 2 wherein said aging engine is organized to remove all entries which are over-age and to broadcast to other units in the fabric an “address removed” message in respect of an over-age address which has the network unit as its source unit. 6. A network unit as in claim 5 wherein the aging engine responds to an “address removed” message to remove the corresponding entry from the database. 7. A network unit as in claim 3 wherein the aging engine determines in respect of a polled entry whether the corresponding media access control address has the network unit as the source unit for that address within the fabric and (i) if the address has the network unit as its source unit and is inactive, removes the entry; (ii) if the address has another unit as its source unit and is inactive, sends an “aging request” message in respect of that address to said another unit; and (iii) in the absence of a response from said another unit that the address is active, removes the entry. 8. A network unit as in claim 1, including a monitor of the other units in the fabric and organized to purge the database at least partially on the occurrence of a change in the number of units in the fabric. 9. A network unit as in claim 8 wherein the unit responds to the addition of a unit to the fabric to purge the database of all entries sourced by any unit in the fabric. 10. A network unit as in claim 8 wherein the unit responds to the removal of a unit from the fabric to purge those entries sourced by the now absent unit. 11. A network unit as in claim 1, including a monitor of the other units in the fabric and organized to effect resynchronization of the database on the occurrence of a change in the number of units in the fabric. 12. A network unit as in claim 11 wherein the network unit is organized to broadcast to the other units messages containing those addresses for which it is the source unit. 13. A distributed bridging fabric comprising: a multiplicity of network units mutually organized to constitute a single network entity, wherein: each network unit has a respective multiplicity of user ports for the transmission of data frames to and from an external network, at least one fabric port for the transmission of frames between that network unit and another unit in the fabric: each network unit has a respective forwarding database for containing entries each including a media access control address; each network unit has a respective lookup engine organized for the insertion of an entry into said respective forwarding database on receipt of a data packet at a user port and for the broadcast via each fabric port of an “address added” message identifying a respective media access control address, said respective lookup engine responding to such an “address added” message received from another unit to make a corresponding entry in the respective database; and to annotate an entry to indicate activity of an address in response to an address which is already in said respective database; and each network unit has a respective aging engine organized for the polling of entries in the database, said respective aging engine refreshing an entry for which the media access control address is annotated as active and organized for the selective removal of inactive entries from the respective database. 14. A distributed bridging fabric as in claim 13 wherein each entry includes a source field indicating the source unit within the fabric for a packet having that media access control address. 15. A distributed bridging fabric as in claim 13 wherein said respective aging engine is organized to determine whether an address is active, to remove entries for which the corresponding media access control address is inactive and to cause the broadcast to other units in the fabric of an “address active” message in respect of active addresses for which the respective network unit was the source unit within the fabric for that address. 16. A distributed bridging fabric as in claim 13 wherein said respective aging engine is organized to remove all entries which are over-age and to broadcast to other units in the fabric an “address removed” message in respect of an over-age address which has the respective network unit as its source unit. 17. A distributed bridging fabric as in claim 16 wherein the respective aging engine responds to an “address removed” message to remove the corresponding entry from the respective database. 18. A distributed bridging fabric as in claim 14 wherein the respective aging engine determines in respect of a polled entry whether the corresponding media access control address has the respective network unit as the source unit for that address within the fabric and (iv) if the address has the respective network unit as its source unit and is inactive, removes the entry; (v) if the address has another unit as its source unit and is inactive, sends an “aging request” message in respect of that address to said another unit; and (vi) in the absence of a response from said another unit that the address is active, removes the entry. 19. A distributed bridging fabric as in claim 13, wherein each network unit includes a respective monitor of the other network units in the fabric and organized to purge the respective database at least partially on the occurrence of a change in the number of units in the fabric. 20. A distributed bridging fabric as in claim 19 wherein the unit responds to the addition of a unit to the fabric to purge the database of all entries sourced by any unit in the fabric. 21. A distributed bridging fabric as in claim 19 wherein the unit responds to the removal of a unit from the fabric to purge those entries sourced by the now absent unit. 22. A distributed bridging fabric as in claim 13, wherein each network unit includes a respective monitor of the other units in the fabric and organized to effect resynchronization of the database on the occurrence of a change in the number of units in the fabric. 23. A distributed bridging fabric as in claim 22 wherein each network unit is organized to broadcast to the other network units messages containing those addresses for which it is the source unit. 24. A method of operating a network unit in a distributed bridging fabric, the network unit comprising a multiplicity of user ports for the transmission of data frames to and from an external network and at least one fabric port for the transmission of frames between said network unit and another unit in the fabric, the method comprising: (a) operating a forwarding database to contain entries each including a media access control address; (b) inserting an entry into said forwarding database on receipt of a data packet at a user port; (c) broadcasting via each fabric port an “address added” message identifying a respective media access control address; (d) responding to such an “address added” message received from another unit to make a corresponding entry in said forwarding database; (e) annotating an entry in the database to indicate activity of an address in response to an address which is already in said forwarding database; (f) examining entries in said forwarding database in turn; (g) refreshing an entry for which the respective media access control address is annotated as active; and (h) selectively removing inactive entries from said forwarding database. 25. A method as in claim 24 wherein each entry includes a source field indicating whether the respective media access control address was derived from a packet for which the network unit or another unit was the source unit for that packet within the fabric. 26. A method as in claim 25 wherein the source field identifies said source unit. 27. A method as in claim 26 further comprising determining whether an address is active, removing entries for which the corresponding media access control address is inactive and broadcasting to other units in the fabric an “address active” message in respect of active addresses for which the network unit was the source unit within the fabric for that address. 28. A method as in claim 26 further comprising removing from said forwarding database all entries which are over-age and broadcasting to other units in the fabric an “address removed” message in respect of an over-age address which has the network unit as its source unit. 29. A method as in claim 28 further comprising responding to an “address removed” message to remove the corresponding entry from said forwarding database. 30. A method as in claim 26 further comprising determining in respect of a entry in said forwarding database whether the corresponding media access control address has the network unit as the source unit for that address within the fabric and (a) if the address has the network unit as its source unit and is inactive, removing the entry; (b) if the address has another unit as its source unit and is inactive, sending an “aging request” message in respect of that address to said another unit; and (c) in the absence of a response from said another unit that the address is active, removing the entry. 31. A method as in claim 24, further comprising monitoring other units in the fabric and purging said forwarding database at least partially on the occurrence of a change in the number of units in the fabric. 32. A method as in claim 31 further comprising responding to the addition of a unit to the fabric to purge said forwarding database of all entries sourced by any unit in the fabric. 33. A method as in claim 31 further comprising responding to the removal of a unit from the fabric to purge those entries sourced by the now absent unit. 34. A method as in claim 24, further comprising monitoring other units in the fabric and resynchronizing said forwarding database on the occurrence of a change in the number of units in the fabric. 35. A method as in claim 24, further comprising broadcasting to the other units messages containing those addresses for which said network unit is the source unit. | FIELD OF THE INVENTION This invention relates to packet-switched communication networks, particularly though not exclusively those employing media access control (MAC) addressing and network (IP) addressing of packets. More particularly the invention relates to a fabric of units organised to provide distributed bridging and units intended for or capable of use in such a fabric. Herein ‘bridging’ refers to the forwarding of a frame or packet according to its ‘layer 2’ (Media Access Control) addressing. BACKGROUND TO THE INVENTION It is known, particularly for network switches, to interconnect a multiplicity of network units into a switching ‘fabric’ so that in effect, and particularly in relation to the external network, the units act as a single network entity. One of the purposes of a fabric of network units is the provision of ‘resiliency’ that is to say the ability of the switching fabric to continue operation, so far as is feasible, notwithstanding a fault in or removal of one of the units of the fabric or one of the links connecting the units of the fabric. Early forms of such a fabric were in the form of a daisy chain or ring although more recently mesh forms of a fabric have been developed; and the invention is applicable in all such forms. BACKGROUND OF THE INVENTION Where several individual data-switching units are connected to form a single distributed fabric, the bridging functionality may be distributed amongst the individual units within the fabric. Preferably the entire fabric appears to other network entities as if it were a single bridge. It is desirable to share the workload between the units as much as possible, to maximize the data forwarding performance, and to minimize the dependence on any single unit or connection within the fabric. The functionalities required of a bridge may be divided into two broad categories; data plane, and control plane. The data plane functionalities relate directly to the forwarding of the data traffic, and the control plane functionalities relate to the overhead activities of establishing the topology of the LAN (Local Area Network) in which the bridge is deployed. More specifically, the data plane includes the VBridges, the fabric ports, the user ports, and the forwarding databases. The control plane includes the protocol entities, which may include in practice, for bridges, LACP (Link Aggregation Control Protocol), and STAP (Spanning Tree Algorithm and Protocol). ‘VBridge’ is a term used herein to mean a bridge which can forward data traffic only within one VLAN (Virtual Local Area Network). If a network is not partitioned into virtual local area networks the term VBridge is synonymous with ‘bridge’. There must appear to be only one forwarding database for each VBridge throughout the fabric, and the entire fabric must appear to be a single entity to the protocols so that the fabric will be a single node in the LAN topology. In order to be able to function as a bridge, a single unit must include at least one VBridge incorporating a forwarding database that has entries each relating a MAC (media access control) address to forwarding data, e.g. an identification of a port from which a frame having that MAC address as a destination address should be sent, and at least two user ports, i.e. physical ports which are not fabric ports, User ports are the unit's physical data interface to entities outside the fabric. In order to form part of a distributed fabric with bridge functionality, a single unit must include at least one ‘fabric port’. A fabric port, which may be either dedicated or configured as such, is a physical port that is used only to connect a unit to another unit within the fabric. Fabric ports and the links between them are always within the fabric so they neither receive frames from nor transmit frames to the external network and are not ‘visible’ to entities outside the fabric. In practice, a product specified to be able to form part of a fabric with bridging functionality would typically include multiple VBridges (as many VBridges as there is VLAN connectivity specified for the unit), multiple forwarding databases (one per VBridge), multiple user ports, and one or more fabric ports. Multiple single bridge units may be connected through their fabric ports to form a distributed fabric, the maximum number of units in the fabric and the topology of the fabric being dependent on the product itself. The bridging of data traffic through a distributed fabric must appear to be identical to the bridging of data traffic through a single unit. Traffic must be forwarded from an ingress user port to an egress user port identically regardless of whether the user ports are on the same unit or are on different units within the fabric. Traffic should also be filtered identically regardless of which unit has the user ports. If a single unit bridge is able to control the forwarding of a particular frame directly to the egress user port with no flooding of the frame to other user ports, then a distributed fabric's bridge should likewise not flood the traffic to other user ports. SUMMARY OF THE INVENTION An important aspect of achieving for a distributed bridging entity common forwarding functionality and identity of occurrence of flooding throughout the entity is the synchronization of the various forwarding databases. The present invention accordingly concerns a network unit, intended for use in a distributed fabric, which can co-operate with the other units in the fabric to achieve explicit synchronization of the forwarding databases. One aspect of explicit synchronization according to the invention is the broadcasting of a learning event (i.e. the entry of a locally sourced MAC address) to the other units in the fabric. This is preferably achieved by means of special fabric database maintenance packets (herein called ‘maintenance packets’) which be transmitted only via fabric ports and which will cause the search or look-up engines in the other bridges to make corresponding entries, which are preferably annotated to indicate that they have been ‘remotely’ sourced. Another aspect of explicit synchronization according to the invention is the aging of entries in the databases, to remove entries which are not ‘active’. This may be achieved in a variety of ways, which produce in general different volumes of maintenance traffic across the fabric. A further feature of the invention is the purging or resynchronization of a unit's database when another unit joins or leaves the fabric. Further features of the invention will become apparent from the following description of examples with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a single bridge intended for use in a distributed fabric. FIG. 2 illustrates a basic distributed fabric comprising two bridges and a fabric link. FIG. 3 illustrates a basic distributed fabric comprising two units each containing a multiplicity of Vbridges. FIG. 4 is similar to FIG. 3 and shows the logical separation of traffic on different VLANs. FIG. 5 illustrates communication between units in a distributed fabric. FIG. 6 illustrates implicit synchronization in a distributed fabric. FIG. 7 illustrates the occurrence of flooding in a distributed fabric. FIG. 8 illustrates a distributed fabric including aggregated links FIG. 9 illustrates one example of a forwarding database and its operation according to the invention. FIG. 10 illustrates a maintenance packet FIG. 11 illustrates the broadcasting of a leaning event FIG. 12 illustrates one example of the control of aging of entries in forwarding databases in the distributed fabric. FIG. 13 illustrates another example of the control of aging of entries in forwarding databases in the distributed fabric. FIGS. 14 and 15 illustrate another example of the control of aging of entries in forwarding databases in the distributed fabric. FIG. 16 illustrates an example of resynchronization of a database. DETAILED DESCRIPTION In order to indicate the context of the invention, reference will first be made to FIGS. 1 to 8. FIG. 1 illustrates by way of example a single bridge unit 8, which has user ports 1, fabric ports 2 and VBridges 3a, 3b . . . 3n. Each VBridge has its own forwarding database FDB1, FDB2 etc. As is well known a Vbridge has two important features, namely ‘forwarding’ and ‘learning’. For forwarding, the database is accessed by means of a search key (e.g. a ‘destination address’) to obtain the forwarding data, usually a port number, for the packet. The access mechanism depends on the nature of the database. It may be a trie database, a CAM (content addressable memory) or a database accessed by hashing the destination address and so on. For learning, the source address of the packet is checked (using a look-up process similar to that for forwarding) to determine whether the source address is the subject of an entity in the database. If it is not, the source address and ‘forwarding data’ (i.e. the port on which the packet was received) is learned by the database, so that the forwarding data can be recovered when the bridge receives a packet of which the destination address (DA) corresponds to the stored or learnt source address. It will be presumed that the forwarding databases all have the (well-known) forwarding and learning facilities just described. Another known feature of forwarding databases is aging. There are several forms, but in essence each entry is (subject to some exclusions) automatically removed from the databases by means of an aging clock. For example, each entry may have a field, which indicates either the age of the entry or the time period within which the entry was made. Periodically the database is scanned to effect removal of those entries, which are too old according to the selected aging criterion. In practice the aging procedure has two other preferred features. One is that selected entries (such as static addresses) may be immune to the aging procedure, for example by the provision of an ‘AGING OK’ field that has to be set to permit aging. Another feature is ‘refreshing’. This feature allows the updating of the aging field associated with the entry on the reception of a packet, which has a source, MAC address that is already in the database. Depending on how age is represented, the refreshing may be effected either by resetting the age of the entry to zero or by resetting the age to the current time according to the aging clock. The particular mechanism is in general unimportant. Essentially the aging mechanism acts to remove, or at least select for removal, those entries which on the criteria employed are not ‘active’ within some time interval, which depends on the design and the nature of the traffic. VBridges Any VBridge may connect to any of the user ports within a unit. Where more than one VBridge is connected to a particular user port, the traffic passing through that port would normally be tagged with a VLAN identifier according to IEEE Standard 802.1q so that each VLAN's traffic is logically separate. Where only one VBridge is connected to a user port, it would not normally be necessary for the traffic to be tagged with a VLAN identifier for separation. So that any VBridge appears to be continuous across all of the units within a fabric, every unit in a fabric would normally need to implement the same set of VBridges and each implemented VBridge must have connectivity through the fabric ports to its counterpart in every other unit. Since the links between the fabric ports on the units must carry traffic for each of the VBridges, and since the logical separation of each VBridge must be maintained, all traffic carried by the links between the fabric ports must carry some means of identifying which VLAN the traffic is for. Most products allow the ‘creation’ and ‘destruction’ of VBridges. Where VBridges are created or destroyed in a distributed fabric, the creation or destruction must be synchronized across the units so that every unit continues to implement the set of VBridges required so that each VBridge appears to be continuous through the fabric. Simultaneously with this, when a VBridge is created or destroyed, the corresponding logical link within the fabric link must be created or destroyed. Also, where a fabric is established by connecting units that have differing VBridges implemented, there must be some method of synchronizing the VBridges and fabric link logical connections. FIG. 2 shows a distributed fabric consisting of two units 1 and 2 connected by a single fabric link. Host A is connected to user port 1.1 on unit 1 and host B is connected to user port 2.5 on unit 2. It is assumed that host A and host B have been having a bi-directional MAC-addressed conversation and so the distribute bridge that connects them has had an opportunity to learn both of their MAC addresses. Only the traffic flow form host A to host B is shown, the traffic having a MAC source address (SA) of ‘A’ and a MAC destination address (DA) of ‘B’. It may be assumed that the traffic flow from host B to host A is similar in the opposite direction and with opposite MAC addressing. Since the user port to which host B is connected is on unit 2, the Vbridge in unit 1 forwards the traffic only to its fabric port. Unit 1 does not flood the traffic to any of its user ports. When unit 2 receives the traffic from its fabric port, it forwards it directly to user port 2.5 and does not flood it to any other user port. FIG. 3 is an example of two units Unit 1 and Unit 2 each having the same general layout as the unit shown in FIG. 1, connected through a single fabric link 10 (between the fabric ports 2) to form a distributed fabric. The actual connection topologies and number of fabric ports involved depend on the product's capabilities, but the principles are the same regardless of the fabric's topology. Since the fabric ports may not be connected to any unit outside of the fabric, it does not matter what mechanism is user to identify the traffic so that the VLANs carried by the fabric links may be kept logically separate. An example of a suitable mechanism would be the addition of a VLAN tag according to IEEE Standard 802.1q to all fabric link traffic. Normally, the mechanism employed is defined by a product's hardware capabilities. FIG. 4 resembles FIG. 3 but diagrammatically shows the three logically separated traffic flows on the single physical fabric link. Each VBridge in each unit has its own logical connection to its counterpart in the other unit. There are as many logically separated connections through each fabric link as there are VBridges in the distributed fabric switch. Forwarding Databases Each VBridge forwards MAC addressed frames and learns MAC address locations into a forwarding database in accordance with IEEE Standards 802.1d and 802.1q. Each VBridge should contain its own logically separate address databases. This means that a MAC address learned (according to IEEE Standard 802.1d) within one VLAN would not be available to VBridges forwarding within other VLANs. Each forwarding database within each unit in the fabric contains, for each MAC address, the port on which that MAC address was learned (and so the port to which to forward any traffic destined to that MAC address). Within each units forwarding database, the port against which a MAC address is learnt may be either a user port or a fabric port and, where it is a fabric port, at least one other unit in the fabric would have to further forward any traffic destined to that MAC address toward a user port. In this way, traffic destined to a particular MAC address may be forwarded by several VBridges within several units with all but the last of the VBridges in the flow being directed by its forwarding database to forward the traffic to a fabric port. Ultimately the last unit in the flow must forward the traffic to a user port and so its forwarding database would have the appropriate user port against the MAC address. It is feasible to provide direct hardware support for the learning of MAC addresses directly against any user port within the fabric, regardless of which unit the user port resides on. The hardware then identifies when a user port is on another unit and forwards traffic for that user port to a fabric port instead. On these products, it is not necessary to reference the fabric ports in the forwarding databases and an identifier for the user port is used instead. The identifier for each user port must then be unique within the entire distributed fabric. Each frame forwarded by the fabric's bridging functionality enters the fabric at a user port and, ultimately, exits the fabric at a user port. The possibility that the frame may have to be forwarded across one or more fabric links and be forwarded independently by more than one unit's VBridge does not change the appearance that the fabric is a single bridge. However, to maintain the appearance of being a single bridge, only a single forwarding database per distributed VBridge should appear at any management interface. To achieve this, any forwarding database entries containing a fabric port must not be shown at the user interfaces. FIG. 5 shows by way of example the fabric consisting of two units, Unit 1 and Unit 2 connected by a single fabric link 10 as before. The units in this example do not have hardware support for the direct referencing of user ports residing on different units. Each unit contains only one VBridge (VBridge 1) each containing a forwarding database. Host A is connected to a user port 1.1 on unit 1 and host B is connected to a user port 2.5 on unit 2. The forwarding database of each unit's VBridge has an entry for the MAC address of both hosts with the fabric port learned against the MAC address connected to the other unit. The forwarding database report returned via a management user interface (not shown) is the combination of both VBridges' forwarding databases' contents but with the entries containing the fabric ports suppressed to leave only the entries containing a user port. Unit or Fabric Link Loss Whenever a unit disappears from a distributed fabric or a fabric link loses connectivity the remaining units may have to modify the contents of their forwarding databases. Any MAC addresses learnt against a fabric port must be removed from all forwarding databases if that fabric port loses connectivity. If connectivity to a particular unit is lost, all of the remaining units in the fabric must remove from their forwarding databases any MAC addresses learnt against a user port on the lost unit. Address Learning Each forwarding database in each VBridge in each unit learns MAC addresses in accordance with IEEE Standard 802.1d. Whenever MAC addressed traffic arrives at any port (fabric or user) of a unit, the unit has an opportunity to learn the MAC source address of the traffic and to populate the forwarding database of the appropriate VBridge with the MAC address against the port through which the traffic arrived. If each unit were to take opportunities to learn MAC addresses independently of the other units in the fabric then, in most cases, the MAC address would be learnt consistently by all of the units that the traffic traverses. The resultant forwarding databases in each unit would contain entries that are effectively synchronized with each other to allow traffic to be forwarded through the fabric as if the fabric were a single switch. This independent learning toward a consistent set of forwarding databases is called herein “implicit synchronization”. Although implicit synchronization of the forwarding databases in the fabric works in most cases, there are several scenarios in which at least one of the units in the fabric does not receive an opportunity to learn a MAC address to which it is required to forward traffic. In these cases, if implicit synchronization is the only synchronization mechanism supported, then the unit has no choice but to ‘flood’ the traffic. This is, clearly, undesirable. The general solution to these cases is to have the forwarding databases of each unit communicate directly with their counterparts in the other units to share the learnt MAC addresses. This is called “explicit synchronization”. Implicit Synchronization As indicated above, implicit synchronization of the forwarding databases is achieved when each VBridge of each unit in the fabric learns addresses into its forwarding databases directly from the source MAC addresses of the traffic forwarded by the unit. Normally, since every unit in the path between the ingress user port and the egress user port forwards traffic, every unit with a need to learn the MAC address will have the opportunity to learn it and every unit in the fabric may control traffic forwarding and filtering consistently. Implicit forwarding database synchronization works in circumstances when all units in the fabric see required MAC addresses as source addresses and so have an opportunity to learn. In the example shown in FIG. 6, if Host A sends MAC addressed traffic to Host B, then the traffic will be forwarded by both Unit 1 and Unit 2 and the respective VBridge in both units will have the opportunity to learn MAC address A. If host B now sends MAC addressed traffic back to Host A then the traffic will again be forwarded by both units and the respective VBridge in both units will have the opportunity to learn MAC address B. Traffic may now flow between Host A and Host B in either direction; both units are able to control the traffic fully so that no flooding need occur. If Host C now sends traffic to Host B then, because the respective VBridge 1 in Unit 2 has already learnt MAC address B, the traffic will be forwarded directly to host B and no flooding will result. Only Unit 2 will, therefore, have an opportunity to learn MAC address C. A further traffic stream from Host A to Host C would now be controlled by the VBridge in Unit 2, but would be flooded by the VBridge in Unit 1. In this scenario the forwarding databases have not been implicitly synchronized and the fabric would not behave identically to a single switch. Another example of where the forwarding databases would not be synchronized implicitly is where a distributed router is implemented as described in U.S. 2003-0147412-A1 (Weyman et al). As is described therein, the unit that first receives the traffic routes it and then, if the egress port is on a different unit, it is bridged through the distributed bridge functionality to the egress port. This means that only the ingress unit will have the opportunity to learn the source MAC address. The result of this is that any traffic routed by the distributed router would be partially flooded unless additional MAC address learning opportunities were presented. FIG. 7 shows an example of the traffic flow through a distributed fabric including both a distributed bridge and a distributed router. Host A, with a MAC address of ‘MACA’ and an IP address of ‘IPA’ is connected to unit 1. Host B, with a MAC address of ‘MACB’ and an IP address of ‘IPB’ is connected to unit 2. The distributed router itself has a MAC address of ‘MACR’. This may be achieved as described in Weyman et al., supra, by the lending of a MAC address by Unit 1 to Unit 2. Only the traffic flow from host A to host B is shown, but it may be assumed that there is also a symmetrical traffic flow from host B to host A. Host A is connected to VBridge 1.1 but host B is connected to VBridge 2.2. Because of this the traffic is required to traverse the router. Host A sends its traffic to the MAC address of the router and so it is bridged to the router Ra in unit 1. Unit 1's router forwards the traffic on to VBridge 1.2 but in doing so changes the MAC DA to be MACB and the MAC SA to be MACR. Unit 2 receives the traffic into VBridge 2.2 and, since it is now addressed to MACB, bridges it directly to the user port on which host B is connected. Unit 2 never gets an opportunity to learn MAC address A. Opposite direction traffic from host B to host A would be routed in unit 2 and, when forwarding onward to MACA, would be flooded to all user ports by unit 2. Explicit Synchronization Accordingly, in order to avoid excessive traffic flooding especially when implicit synchronization of the forwarding databases is not sufficient, the present invention employs explicit synchronization. It may be used either in addition to, or entirely instead of, implicit synchronization. Explicit synchronization requires that the forwarding databases of the VBridges communicate directly with each other and exchange knowledge of the MAC addresses required by each VBridge. Where explicit synchronization is used in support of implicit synchronization, the MAC address knowledge exchange may be limited to the required information that was not synchronized implicitly. Where explicit synchronization is used without implicit synchronization no VBridge would learn MAC addresses directly against the fabric port and so all MAC address information would need to be exchanged between units. Explicit synchronization could theoretically be achieved by each unit letting all other units know about all addresses it has in its forwarding databases. This is relatively simple and does not require any particular hardware support but has the disadvantage that, if the forwarding databases were large, a large amount of information exchange would be required. The information exchange would occur regardless of whether any other units required the forwarding database contents in order to control their user traffic. Rather than having all units in the fabric share their forwarding database information indiscriminately, the present invention relies on specific events for initiating the forwarding of database information from a unit. In normal bridge operation (for example in accordance with IEEE Standard 802.1d), MAC addresses in the forwarding databases are continually refreshed so long as traffic continues to arrive from the MAC address. This continual refreshing effectively suspends the aging out and removal of the MAC addresses from the forwarding databases. Where a forwarding database has been populated with a MAC address as a result of explicit synchronization, the MAC address would not have been seen as a source address by the unit and so the normal refresh of the address wouldn't occur. Various schemes for dealing with aging are described later. Static Addresses A forwarding database of a bridge may be directly populated with a number of MAC addresses as the result of requests from a management entity. These forwarding database entries are termed “static” and must continue to be present until management requests that they be removed. Where static addresses are added to the fabric, all units within the fabric should populate their forwarding databases consistently with each other so that traffic arriving at any port on any unit within the fabric would always be forwarded to the required egress port with no flooding. Aggregated Links Bridges may support aggregated links where the port members of a link may be distributed amongst the units of a fabric. Traffic may be received on any member port of an aggregated link and be treated as if it was from a single logical link and, likewise, traffic transmitted to an aggregated link may be transmitted to any of the member ports in accordance with some traffic distribution algorithm, but, to avoid duplication, each frame must be transmitted to only one member port. This presents a problem where an aggregated link spans more than one unit in the fabric because, effectively, more than one VBridge would have a direct connection to the same logical link. Additional inter-unit communication is required to resolve the problem. Since an aggregated link is a single logical connection, any identification index for that aggregated link needs to be coordinated between all units in the fabric. For example, all units within a fabric would coordinate and agree on a common ‘ifindex’ for each aggregated link and, where the aggregated link is referenced in a protocol data unit, all units would use the same value of the reference. For the purposes of transmitting and receiving protocol data units on the aggregated link where the protocol considers the aggregated link to be a single logical link (such as STP), each unit on the fabric must coordinate so that protocol data units are handled consistently. An example of a way in which this could be achieved is to nominate an “owner” unit for each aggregated link and only to allow that unit to process protocol data units for the aggregated link. Other units would forward any protocol data units to the owner unit for processing and only the owner unit would forward protocol data units to the aggregated link. Address Learning Any addresses learnt against an aggregated link must be learnt against the aggregated link itself rather than the member ports. This ensures that any traffic destined to the learnt address can be forwarded to an aggregated link member port according to the traffic distribution algorithm. Where traffic arrives at a unit through a fabric port, and where the traffic was originally received into the fabric through an aggregated link, the unit must learn the traffic's source MAC address against the aggregated link rather than its fabric port. This then allows the units VBridges to forward traffic destined to that MAC address according to the fabric's aggregated link traffic distribution algorithm. Where forwarding databases are synchronized implicitly by allowing the learning of MAC addresses against fabric ports, this learning against the aggregated links can only be achieved if additional information is embedded in the traffic. The extra information must indicate if the fabric originally received the traffic through an aggregated link and, if so, which aggregated link. The embedding of the extra information would normally require the support of the switch hardware. Where each units VBridges are learning addresses independently of their counterparts in the other units in the fabric, and where forwarding database synchronization is only achieved implicitly, this can result in some units in the fabric learning an address against an aggregated link and other units not. In the example shown in FIG. 8, traffic flows from host A to host B via the member link of aggregated link 1 that is on unit 2. Unit 2, therefore, gets an opportunity to learn MAC address A against aggregated link 1 whereas unit 2 does not. Likewise, since traffic flows from host B to host A via the member link of aggregated link 2 that is on unit 1, unit 1 gets the opportunity to learn MAC address B whereas unit 2 does not. In this scenario, traffic destined for MAC address B would be flooded by unit 2 indefinitely and traffic destined for MAC address A would be flooded by unit 1 indefinitely. To avoid excessive traffic flooding it is highly desirable that where distributed aggregated links are supported, explicit forwarding database synchronization also be supported. Distribution A consequence of the provision of a distributed fabric is a requirement that the units in the fabric appear to implement the control protocols as a single position in the network topology only once even though several units may cooperate to share the implementation of a particular protocol. It is not a requirement that the implementation of each protocol be distributed across all of the units in a fabric, but it is desirable that traffic connectivity should be recovered quickly if any unit or any fabric link should fail. Where a protocol implemented in only one unit (the “master” unit for that protocol), it may be necessary for an implementation to share the protocol state information amongst all units in the fabric for backup purposes ready for the failure of the master unit. This may be achieved as described in our prior application No. 0408947.0 Synchronization Events FIG. 9 illustrates an example of the operation of a forwarding database suitable for use in the present invention. A lookup (LU) engine 90 controls a forwarding database 91. The database 91 contains entries each comprising an ‘active’ flag field (AF), an age field (AGE) and a unit ID field, which will indicate whether the entry was sourced locally or from another, ‘remote’ unit in the fabric. This field could in some circumstances merely distinguish between ‘local’ and remote but preferably indicates unit ID of the unit (usually a number), within the fabric, which was the ‘source’ unit for the MAC address. Each entry includes the relevant MAC address, e.g. MAC ADD 1, MAC ADD 2 etc. and the relevant forwarding data FD1, FD2 etc. The organization of the look-up (LU) engine 90 depends on that of the database 91, which may be a tree-type, a trie type or other type according to preference. The primary task of the look-up engine 91 is to respond to an input MAC address of a frame to obtain forwarding data, such as a port mask, which will determine the port or ports from which the frame will be forwarded. Shown separately from the LU engine for convenience, but in practice part of the LU engine, are two functions which may be implemented in hardware. Block 92 determines whether an input MAC address is already in the database. If it is not, then the MAC address is learned (block 93), i.e. is made the subject of a new entry comprising the MAC address and its forwarding data. If the MAC address is already in the database the active flag field AF will be set (block 93) The database is also periodically polled by an aging engine 95, which may be constituted by software process and has recourse to an aging clock 96. The entries in the database are examined in turn to determine whether the ‘active’ flag is set. If so, the flag is cleared and the age field refreshed, e.g. reset to the current time indicated by the aging clock or reset to zero if the aging convention dictates. In the former case the test for an over-age entry is performed by subtracting the time in the age field from a current time; in the latter case the test requires testing the age in the age field against an age limit. FIG. 9 also includes a purge function 97 controlled by a ‘fabric monitor’ 98, which will be described later. Explicit synchronization requires the sending of internal maintenance packets between the units of the fabric. One such packet is shown in FIG. 10. it includes a header, organized in any suitable manner to ensure that it will egress only from a fabric port, an operation code for recognition by receiving units, a MAC address and relevant data (as will be described). In what follows three techniques for explicit synchronization will be described. They differ both in respect of the ‘events’ which are communicated across the fabric and the actions taken in response to those events. They are conveniently described as, respectively, ‘Learning events only sent’, ‘Learning and Aging events sent’ and ‘Learning events with aging requests’. Learning Events Only Sent In this technique each unit will broadcast a learnt address to the rest of the fabric when the address gets added to the local address database. Periodically each unit will sequence through its database checking for addresses to age out. Both locally and remotely sourced addresses will be aged out if found to have been inactive for the aging period and allowed to be aged out. For locally sourced addresses the hardware will be interrogated to determine whether the address has been active or not If the address is still active an “address active” message will be broadcast to the rest of the fabric. If the address has been inactive for the aging period then the address is removed from the database and no message is sent. For remotely sourced addresses, if an “address active” message has not been received within the last aging period then the address will be removed from the Address Database. FIGS. 11 and 12 illustrate schematically the organization of explicit synchronization in which only ‘Learning events’ are broadcast as just outlined. In this technique a unit will inform other units by means of maintenance packets of the addition of a MAC address to its database and the detection of ‘active’ locally sourced addresses. In particular, as shown by blocks 110 and 111, when the local unit adds a MAC address to the respective local database 91 (FIG. 9) the unit will broadcast a maintenance packet (FIG. 10) containing this MAC address to the other units of the fabric. Each other unit will add the MAC address to its database (block 112) as it would a normally locally sourced MAC address but would set the local/remote field to remote. If this filed is intended to contain the Unit ID, the packet 100 will include a data field containing the Unit ID of the MAC address's source unit. Also, if a unit in response to the MAC address of a packet discovers that the MAC address is already in the database (block 92), it will, in addition to setting the active flag AF, broadcast to the rest of the fabric a maintenance packet identifying the MAC address and the fact that the address is active (by means of a suitable flag). Such a packet will have, for example, an operation code that will prevent its causing the retransmission of an ‘address active’ message to the rest of the fabric when the active flag for the MAC address is set in a database other than that address' source unit. The LU engine may alternatively be organized to the same effect so as to transmit an address active message only in respect of locally sourced addresses. Periodically, as indicated by block 95 in FIG. 9, each unit sequences through its database checking for addresses to age out. Both local and remote addresses will be aged out of they have been inactive (as shown by a ‘clear’ active flag). Thus as shown in FIG. 12, each database entry is checked, block 121 to determine whether it is local or remote (decision 122). If the address is local it is checked to see whether it is active, has had the active flag set since the previous refresh. If the address is not active, it is removed (block 124) from the database and the routine returns to the start (S) to check the next entry. If the (local) address is active, then an “address active” message is broadcast (block 125) to the rest of the fabric. If the address is remote then it is checked to see whether it is active (decision 126). If it is active no action is taken. If the address is inactive, the database entry is removed ((block 127). One advantage of this technique is that over-age addresses (whether local or remote) will not linger in the database. Once a unit stops sending “address active” messages in respect of a particular MAC address the other units within the fabric will age out the address from their own databases albeit only at the end of an aging period. Furthermore the addresses would propagate across the fabric reasonably quickly and ‘flooding’ of unknown addresses can be reduced to a minimum. However, the amount of maintenance traffic as a result of the “address active” messages plus the “address learnt” messages could be quite large. There would be one “Address Active” message for every entry in the Address Database sent to every unit in the fabric, every aging period. Also, if an “address active” message is lost, remotely sourced addresses may be prematurely aged out, resulting in the ‘flooding’ of an address unknown to one of the databases other than the source database Learning and Aging Events Sent In this technique, each unit, within the fabric, sends out learning events to the entire fabric as before. When a source unit of an address determines that the address should be aged out of the address database, it sends out an aging message to the entire fabric, i.e. a maintenance frame as shown in FIG. 10 with a data flag denoting that the address has been aged out of the source unit's database. The individual units only routinely age out locally sourced addresses, informing the rest of the fabric; remotely sourced addresses are removed from the address database as a result of the reception of an “address aged” message from that address's source unit. This technique employs the same broadcasting of ‘learning events’ as described with reference to FIG. 11. The aging engine is organized as shown in FIG. 13. Each database entry is checked, block 131, to determine whether it is local or remote (decision 132). No action is taken if the address is ‘remote’ If the address is local it is checked to see whether it is active (decision 133). If the (local) address is active there is no action. It the address is not active, the unit sends an “address removed” message to the rest of the fabric (block 134) and the entry is removed (block 135). When a unit in the fabric receives such an “address removed” packet, (block 136) it checks its database for the entry (block 137) and removes the entry (block 138). This second technique would generate less maintenance traffic than the “Learning events only” technique, because there is only one “address added” and one “address removed” message throughout the life of that address on the given VLAN/port combination. The propagation of addresses across the fabric and the reduction of ‘flooding’ are similar to the previously described technique. Moreover, addresses will be aged out from the remaining units within the fabric reasonably quickly. If however any “address removed” message is lost an address may remain indefinitely in the remote unit's database. If the delivery mechanism could guarantee delivery and processing of the synchronization messages then this possible disadvantage would be avoided. Learning Events with Aging Requests A combination of the two previous options would be to have each unit broadcast its learning events to the fabric, and to have each individual unit age its address database contents. When a unit determines that a remotely sourced address needs to be aged then instead of actually performing the removal straight away, a request is made to the source unit to determine whether the address is still active or not. If the source unit responds that the address is no longer active then the address can be removed from the local address database—if the source unit responds that the address is still active then the address age is reset and it is left in the database. If no response is received from the source unit, the address should be removed from the address database. More particularly, in this technique the broadcasting of learning events proceeds as described with reference to FIG. 11. The aging process is shown in FIGS. 14 and 15. The aging engine polls each entry in turn (block 141). If the address is locally sourced (decision 142) it is checked to see whether it is active (decision 143). If so, no action is taken and the next entry is polled. If the (local) entry is inactive, it is removed (block 144). If the address is remotely sourced (decision 142) is checked to see whether it is active (decision 145). Again, no action is made in respect of this entry if the address is active. If the address is not active, an “aging request” is sent to that address's source unit, as identified in the entry, and a timer is started. The action of the source unit is shown in FIG. 15. On receipt of the “aging request” (block 151) it checks the relevant database entry (block 152) to see whether it is active (decision 153). If it is not no action is taken. If the address is active, the source unit sends an “address active” message back to at least to the requesting unit (block 154). The requesting unit, determines whether is has received an “address active” message for this address within a predetermined time (decision 147 and time out 149). If the “address active” message has been received, the entry is refreshed (block 148). If the timer times out without reception of the “address active” message, the entry is removed (block 150). This technique has the advantages that an over-age address cannot get remain in the address database, the addresses will propagate across the fabric reasonably quickly, flooding is reduced to a minimum and addresses will be aged out from the units within the fabric reasonably quickly. However, the amount of maintenance traffic would be double that of the technique compared to that described with reference to FIG. 13. Changes to a Fabric There is a choice of actions to take when a fabric changes, i.e when a unit is added to or removed from a fabric. There are broadly two possible options available, purging the databases or resynchronization of them. Purge Databases This option means that when a unit gets added to a fabric the address databases on all the fabric units are purged. All addresses are removed and the newly formed fabric starts with an unoccupied address database. This does not require synchronization of existing addresses or any additional maintenance traffic overhead during the forming of a new fabric. However there will be flooding of addresses previously learnt, even though data traffic paths may have been unaffected by the change. The purging option is also applicable when a unit leaves the fabric. In this case the remaining units purge their databases of all addresses that were sourced from the unit that has departed. If they did not, owing to the absence of the source unit for those addresses, and the consequent absence of sending or response to relevant aging events, the forwarding databases could remain populated indefinitely with those addresses. Reverting to FIG. 9, a purging function 97 will depending on the fabric ‘event’ either purge the database entirely (e.g. when a unit joins the fabric) or purge the database of those entries which have been sourced from a now absent unit. It is known from for example GB patent 2383507 for the units in a fabric to exchange control frames by means of which each of the units in a fabric has information on the operational status of each of the other units and it is proposed in Goodfellow et al., U.S. Ser. No. 10/751,930 filed 7 Jan. 2004 and commonly assigned herewith for the units in a fabric to exchange ‘fabric protocol’ packets which provide (among other things) similar information. A ‘fabric monitor’ 98 implemented according to either scheme (or otherwise) therefore has sufficient information for the control of the purging function 97. The purging of a database of those addresses which have been sourced from a particular (now absent) unit makes the use of a unit 1D field desirable in the database. Re-Synchronize Databases This option means that when a unit gets added to a fabric the address databases of all the units of the newly formed fabric are merged together to form a single, consistent database on all the units. This could be achieved by each unit in the fabric broadcasting the contents of the address database which were sourced on itself, or possibly a single nominated unit within the fabric could broadcast the entire contents of its address database. FIG. 16 shows the process by way of example for one of the units. The status of the fabric units is monitored for example by means of a fabric monitor 98 (FIG. 9). If a unit has been added (block 161), the database is ‘resynchronized’, in this example by broadcasting (by means of maintenance packets) those addresses sourced on the respective unit (block 1623). Each remaining unit in the fabric will ‘resynchronize’ in like manner. | <SOH> BACKGROUND TO THE INVENTION <EOH>It is known, particularly for network switches, to interconnect a multiplicity of network units into a switching ‘fabric’ so that in effect, and particularly in relation to the external network, the units act as a single network entity. One of the purposes of a fabric of network units is the provision of ‘resiliency’ that is to say the ability of the switching fabric to continue operation, so far as is feasible, notwithstanding a fault in or removal of one of the units of the fabric or one of the links connecting the units of the fabric. Early forms of such a fabric were in the form of a daisy chain or ring although more recently mesh forms of a fabric have been developed; and the invention is applicable in all such forms. | <SOH> SUMMARY OF THE INVENTION <EOH>An important aspect of achieving for a distributed bridging entity common forwarding functionality and identity of occurrence of flooding throughout the entity is the synchronization of the various forwarding databases. The present invention accordingly concerns a network unit, intended for use in a distributed fabric, which can co-operate with the other units in the fabric to achieve explicit synchronization of the forwarding databases. One aspect of explicit synchronization according to the invention is the broadcasting of a learning event (i.e. the entry of a locally sourced MAC address) to the other units in the fabric. This is preferably achieved by means of special fabric database maintenance packets (herein called ‘maintenance packets’) which be transmitted only via fabric ports and which will cause the search or look-up engines in the other bridges to make corresponding entries, which are preferably annotated to indicate that they have been ‘remotely’ sourced. Another aspect of explicit synchronization according to the invention is the aging of entries in the databases, to remove entries which are not ‘active’. This may be achieved in a variety of ways, which produce in general different volumes of maintenance traffic across the fabric. A further feature of the invention is the purging or resynchronization of a unit's database when another unit joins or leaves the fabric. Further features of the invention will become apparent from the following description of examples with reference to the accompanying drawings. | 20040709 | 20090127 | 20060216 | 94363.0 | G06F1516 | 0 | COULTER, KENNETH R | DISTRIBUTED BRIDGING WITH SYNCHRONIZATION FORWARDING DATABASES | UNDISCOUNTED | 0 | ACCEPTED | G06F | 2,004 |
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10,886,766 | ACCEPTED | Activated protein C variants with normal cytoprotective activity but reduced anticoagulant activity | Variants (mutants) of recombinant activated protein C (APC) or recombinant protein C (prodrug, capable of being converted to APC) that have substantial reductions in anticoagulant activity but that retain normal levels of anti-apoptotic activity are provided. Two examples of such recombinant APC mutants are KKK191-193AAA-APC and RR229/230M-APC. APC variants and prodrugs of the invention have the desirable property of being cytoprotective (anti-apoptotic effects), while having significantly reduced risk of bleeding. The invention also provides a method of using the APC variants or prodrugs of the invention to treat subjects who will benefit from APC's cytoprotective activities that are independent of APC's anticoagulant activity. These subjects include patients at risk of damage to blood vessels or tissue in various organs caused, at least in part, by apoptosis. At risk patients include, for example, those suffering (severe) sepsis, ischemia/reperfusion injury, ischemic stroke, acute myocardial infarction, acute or chronic neurodegenerative diseases, or those undergoing organ transplantation or chemotherapy, among other conditions. Methods of screening for variants of recombinant protein C or APC that are useful in accordance with the invention are also provided. | 1. A method of protecting cells against damage caused at least in part by apoptosis, comprising administering to subjects a therapeutic dose of variant recombinant activated protein C; wherein said activated protein C includes at least one mutation that differentially affects the activated protein C's anticoagulant activity and cytoprotective activity; wherein said at least one mutation results in the anticoagulant activity, but not the cytoprotective activity, being reduced relative to a wild-type recombinant activated protein C; and wherein said subjects could benefit from APC's cytoprotective activities that are independent of the anticoagulant activity. 2. The method of claim 1, wherein the protease domain of said recombinant activated protein C further has surface loops; wherein said mutations are in residues of said surface loops of said protease domain se domains of said surface loop. 3. The method of claim 2, wherein said surface loops are selected from the group consisting of loop 37, calcium loop, and autolysis loop. 4. The method of claim 3, wherein said mutation is RR229/230AA in the calcium loop. 5. The method of claim 3, wherein said mutation is KKK191-193AAA in loop 37. 6. The method of claim 1, wherein said therapeutic dose of activated protein C is administered as a prodrug. 7. The method of claim 6, wherein said prodrug is a variant of recombinant protein C. 8. The method of claim 1, wherein said subjects comprise patients at risk for damage to blood vessels or other tissue organs caused at least in part by apoptosis. 9. The method of claim 8, wherein said risk for cell damage is the result of any one or more of sepsis, ischemia/reperfusion injury, stroke, ischemic stroke, acute myocardial infarction, acute neurodegenerative disease, chronic neurodegenerative disease, organ transplantation, chemotherapy, and brain radiation injury. 10. The method of claim 9, wherein the chronic neurodegenerative disease is selected from the group consisting of Alzheimer's disease, Down syndrome, Huntington's disease, and Parkinson's disease. 11. The method of claim 1, wherein the therapeutic dose is between about 0.01 mg/kg/hr to about 1.1 mg/kg/hr, continuous infusion for about 4 hours to about 96 hours. 12. A method of protecting cells against damage caused at least in part by apoptosis, comprising exposing said cells to a therapeutic amount of recombinant activated protein C, said recombinant activated protein C having anticoagulant activity and cytoprotective activity, said recombinant activated protein C further having a protease domain comprising surface loops; wherein said activated protein C includes mutations; and wherein said mutations result in the anticoagulant activity, but not the cytoprotective activity, being reduced relative to a wild-type recombinant activated protein C. 13. The method of claim 12, wherein said mutations result in the cytoprotective activity being enhanced relative to a wild-type recombinant activated protein C. 14. The method of claim 12, wherein said mutations are in residues of the surface loops of said protease domain. 15. The method of claim 14, wherein said surface loops are selected from the group consisting of loop 37, calcium loop, and autolysis loop. 16. The method of claim 15, wherein said mutation is RR229/230AA in the calcium loop. 17. The method of claim 15, wherein said mutation is KKK191-193AAA in loop 37. 18. A therapeutic composition comprising an effective amount of a variant recombinant activated protein C, wherein said variant comprises a mutation causing reduced anticoagulant activity and retained or enhanced cytoprotective activity relative to wild-type recombinant or endogenous activated protein C. 19. A therapeutic composition comprising an effective amount of a prodrug, wherein said prodrug comprises a protein C variant, said protein C variant being capable of conversion to an activated protein C variant, wherein said variant comprises a mutation causing reduced anticoagulant activity and retained or enhanced cytoprotective activity relative to wild-type recombinant or endogenous activated protein C. 20. The composition of claim 18 or 19, wherein said activated protein C has a protease domain comprising surface loops and wherein said mutations are in one or more residues of one or more surface loops of said protease domain. 21. The composition of claim 20, wherein at least one of said surface loops is selected from the group consisting of loop 37, calcium loop, and autolysis loop. 22. The composition of claim 21, wherein said mutation is RR229/230AA in the calcium loop. 23. The composition of claim 21, wherein said mutation is KKK191-193AAA in loop 37. 24. The composition of claim 18 or 19, wherein the composition is adapted for delivery to the subject's brain. 25. The composition of claim 18 or 19, further comprising a pharmaceutically acceptable carrier, and optionally other ingredients known to facilitate administration and/or enhance uptake. 26. A method of selecting potentially therapeutic cytoprotective variants of recombinant activated protein C, said activated protein C having a protease domain, comprising: mutating the recombinant activated protein C at a surface loop of said protease domain to make an activated protein C variant; measuring the anticoagulant activity of said activated protein C variant; measuring the anti-apoptotic activity of said activated protein C variant; calculating the ratio of anti-apoptotic activity to anti-coagulant activity; and identifying the activated protein C variant as potentially therapeutic if said ratio is greater than 1.0. 27. A method of selecting potentially therapeutic cytoprotective variants of recombinant protein C, said protein C having a protease domain, comprising: mutating the recombinant protein C at a surface loop of said protease domain to make a protein C variant; converting said protein C variant to an activated protein C variant; measuring the anticoagulant activity of said activated protein C variant; measuring the anti-apoptotic activity of said activated protein C variant; calculating the ratio of anti-apoptotic activity to anti-coagulant activity; and identifying the protein C variant as potentially therapeutic if said ratio is greater than 1.0. 28. The method of claim 26 or 27, wherein the ratio is greater than about 2. 29. The method of claim 28, wherein the ratio is greater than about 4. 30. The method of claim 29, wherein the ratio is greater than about 8. 31. The method of claim 26 or 27, wherein said surface loop is selected from the group consisting of loop 37, calcium loop, and autolysis loop. 32. A method of selecting potentially therapeutic cytoprotective variants of recombinant activated protein C, comprising: (a) providing a library of candidate agents which are variants of protein C or variants of activated protein C, wherein said protein C or activated protein C have a protease domain, wherein said variants comprise at least one mutation at a residue in a surface loop of said protease domain, and wherein said protein C variants are capable of being converted to activated protein C variants; (b) converting said candidate agents that are protein C variants to activated protein C variants; (c) determining anti-apoptotic activity of said activated protein C variants of (a) or (b) in one or more stressed or injured cells by exposing said cells to an apoptotic-inducing concentration of staurosporine in the presence of an amount of a candidate agent; (d) determining anticoagulant activity of said candidate agents that are assayed in (c) by performing a dilute prothrombin time clotting assay; (e) calculating the ratio of the anti-apoptotic activity determined in (c) to the anticoagulant activity of (d); and (f) selecting candidate agents having an anti-apoptotic:anticoagulant activity ratio greater than 1.0. 33. The method of claim 32, wherein said ratio is greater than about 2. 34. The method of claim 33, wherein said ratio is greater than about 4. 35. The method of claim 34, wherein said ratio is greater than about 8. 36. The method of claim 32, wherein said surface loop is selected from the group consisting of loop 37, calcium loop, and autolysis loop 37. An agent selected by the method of any one of claims 26, 27, and 32-36. 38. A method of treating cell stress or injury comprising administering an effective amount of at least one variant of recombinant activated protein C to a subject, such that at least one effect of stress or injury is improved in one or more cell types of the subject. 39. The method of claim 38, wherein the cellular stress or injury is caused by at least one selected from the group consisting of reduced hemoperfusion, hypoxia, ischemia, ischemic stroke, radiation, oxidants, reperfusion injury, and trauma 40. The method of claim 1, 6 or 38, wherein the cells requiring protection against damage are in one or more of the subject's brain, heart, kidney, liver, or epithelial tissues. 41. The method of claim 38, wherein the at least one variant is comprised of at least one mutation selected from the group consisting of activated protein C mutants KKK191-193AAA and RR229/230AA. | FIELD OF THE INVENTION The present invention relates to variants (mutants) of recombinant protein C and activated protein C, an enzyme that normally has anti-thrombotic, anti-inflammatory, and anti-apoptotic activities. The recombinant activated protein C mutants of the invention have markedly reduced anticoagulant activity, but retain near normal anti-apoptotic (cytoprotective) activity, so that the ratio of anti-apoptotic to anticoagulant activity is greater in the variants than it is in wild-type or endogenous activated protein C. This invention also relates to methods of using these variants. The activated protein C variants of the invention are useful as inhibitors of apoptosis or cell death and/or as cell survival factors, especially for cells or tissues of the nervous system, which are stressed or injured. The invention further relates to therapeutic use of the variants of this invention in subjects at risk for cell damage caused at least in part by apoptosis, and to therapeutic compositions comprising such mutant proteins, which compositions should provide the desired cytoprotective benefits while carrying a lower risk of bleeding, a side effect of activated protein C therapy. BACKGROUND OF THE INVENTION Protein C is a member of the class of vitamin K-dependent serine protease coagulation factors. Protein C was originally identified for its anticoagulant and profibrinolytic activities. Protein C circulating in the blood is an inactive zymogen that requires proteolytic activation to regulate blood coagulation through a complex natural feedback mechanism. Human protein C is primarily made in the liver as a single polypeptide of 461 amino acids. This precursor molecule is then post-translationally modified by (i) cleavage of a 42 amino acid signal sequence, (ii) proteolytic removal from the one-chain zymogen of the lysine residue at position 155 and the arginine residue at position 156 to produce the two-chain form (i.e., light chain of 155 amino acid residues attached by disulfide linkage to the serine protease-containing heavy chain of 262 amino acid residues), (iii) carboxylation of the glutamic acid residues clustered in the first 42 amino acids of the light chain resulting in nine gamma-carboxyglutamic acid (Gla) residues, and (iv) glycosylation at four sites (one in the light chain and three in the heavy chain). The heavy chain contains the serine protease triad of Asp257, His211 and Ser360. Similar to most other zymogens of extracellular proteases and the coagulation factors, protein C has a core structure of the chymotrypsin family, having insertions and an N-terminus extension that enable regulation of the zymogen and the enzyme. Of interest are two domains with amino acid sequences similar to epidermal growth factor (EGF). At least a portion of the nucleotide and amino acid sequences for protein C from human, monkey, mouse, rat, hamster, rabbit, dog, cat, goat, pig, horse, and cow are known, as well as mutations and polymorphisms of human protein C (see GenBank accession P04070). Other variants of human protein C are known which affect different biological activities. Activation of protein C is mediated by thromblin, acting at the site between the arginine residue at position number 15 of the heavy chain and the leucine residue at position 16 (chymotrypsin numbering) (See Kisiel, J. Clin. Invest., 64:761-769, 1976; Marlar et al., Blood, 59:1067-1072, 1982; Fisher et al. Protein Science, 3:588-599, 1994). Other proteins including Factor Xa (Haley et al., J. Biol. Chem., 264:16303-16310, 1989), Russell's viper venom, and trypsin (Esmon et al., J. Biol. Chem., 251:2770-2776, 1976) also have been shown to enzymatically cleave and convert inactive protein C to its activated form. Thrombin binds to thrombomodulin, a membrane-bound thrombin receptor on the luminal surface of endothelial cells, thereby blocking the procoagulant activity of thrombin via its exosite I, and enhancing its anticoagulant properties, i.e., activating protein C. As an anticoagulant, activated protein C (APC), aided by its cofactor protein S, cleaves the activated cofactors factor Va and factor VIIa, which are required in the intrinsic coagulation pathway to sustain thrombin formation (Esmon et al., Biochim. Biophys. Acta., 1477:349-360, 2000a), to yield the inactivated cofactors factor Vi and factor VIIIi. The thrombin/thrombomodulin complex mediated activation of protein C is facilitated when protein C binds to the endothelial protein C receptor (EPCR), which localizes protein C to the endothelial cell membrane surface. When complexed with EPCR, APC's anticoagulant activity is inhibited; APC expresses its anticoagulant activity when it dissociates from EPCR, especially when bound to negatively charged phospholipids on activated platelet or endothelial cell membranes. Components of the protein C pathway contribute not only to anticoagulant activity, but also to anti-inflammatory functions (Griffin et al., Sem. Hematology, 39:197-205, 2002). The anti-inflammatory effects of thrombomodulin, recently attributed to its lectin-like domain, can protect mice against neutrophil-mediated tissue damage (Conway et al., J. Exp. Med. 196:565-577, 2002). The murine centrosomal protein CCD41 or centrocyclin, involved in cell-cycle regulation is identical to murine EPCR lacking the first N-terminal 31 amino acids (Rothbarth et al., FEBS Lett., 458:77-80, 1999; Fukodome and Esmon, J. Biol. Chem., 270:5571-5577,1995). EPCR is structurally homologous to the MHC class 1/CD1 family of proteins, most of which are involved in inflammatory processes. This homology suggests that the function of EPCR may not be limited to its ability to localize APC or protein C on the endothelial membrane (Oganesyan et al., J. Biol. Chem., 277:24851-24854, 2002). APC provides EPCR-dependent protection against the lethal effects of E.coli infusion in baboons (Taylor et al., Blood, 95:1680-1686, 2000) and can downregulate proinflammatory cytokine production and favorably alter tissue factor expression or blood pressure in various models (Shu et al., FEBS Lett. 477:208-212, 2000; Isobe et al., Circulation, 104:1171-1175, 2001; Esmon, Ann. Med., 34:598-605, 2002). Inflammation is the body's reaction to injury and infection. Three major events are involved in inflammation: (1) increased blood supply to the injured or infected area; (2) increased capillary permeability enabled by retraction of endothelial cells; and (3) migration of leukocytes out of the capillaries and into the surrounding tissue (hereinafter referred to as cellular infiltration) (Roitt et al., Immunology, Grower Medical Publishing, New York, 1989). Many serious clinical conditions involve underlying inflammatory processes in humans. For example, multiple sclerosis (MS) is an inflammatory disease of the central nervous system. In MS, circulating leukocytes infiltrate inflamed brain endothelium and damage myelin, with resultant impaired nerve conduction and paralysis (Yednock et al., Nature 366:63-66 (1992)). Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of tissue damage caused by self antigen directed antibodies. Auto-antibodies bound to antigens in various organs lead to complement-mediated and inflammatory cell mediated tissue damage (Theofilopoulos, A.N., Encyclopedia of Immunology, pp. 1414-1417 (1992)). APC has not only anticoagulant and anti-inflammatory activities but also anti-apoptotic activity. EPCR has been found to be a required cofactor for the anti-apoptotic activity of APC in certain cells, as APC activation of protease activated receptor-1 (PAR-1) is EPCR-dependent (Riewald et al., Science, 2296:1880-1882, 2002; Cheng et al., Nat. Med., 9:338-342, 2003; Mosnier and Griffin, Biochem. J., 373:65-70, 2003). APC also has been shown potentially to inhibit staurosporine-induced apoptosis in endothelial cells in vitro by modulating the expression of NFκB subunits (Joyce et al., J. Biol. Chem., 276:11199-11203, 2001). Staurosporine-induced apoptosis in human umbilical vein endothelial cells (HUVEC) and tumor necrosis factor-α-mediated injury of HUVEC, based on transcriptional profiling, suggest that APC's inhibition of NFκB signaling causes down regulation of adhesion molecules (Joyce et al., supra, 2001). APC's induction of anti-apoptotic genes (e.g., Bcl2-related protein A1 or Bcl2A1, inhibitor of apoptosis 1 or clAP1, endothelial nitric oxide synthase or eNOS) has been interpreted as a possible mechanism linked to APC's anti-apoptotic effects in a staurosporine model of apoptosis. APC has a remarkable ability to reduce all-cause 28-day mortality by 19% in patients with severe sepsis (Bernard et al., New Engl. J. Med. 344:699-709, 2001a), whereas, potent anticoagulant agents such as antithrombin III and recombinant TFPI have failed in similar phase III clinical trials (Warren et al., JAMA, 286:1869-1878, 2001; Abraham et al., Crit. Care Med., 29:2081-2089). The explanation for this difference may lie in the recently described anti-apoptotic activity of APC, as well as its anti-inflammatory activity. The clinical success of APC in treating sepsis may be related to its direct cellular effects that mediate its anti-apoptotic or anti-inflammatory activity. In spite of the numerous in vivo studies documenting the beneficial effects of APC, there is limited information about the molecular mechanisms responsible for APC's direct anti-inflammatory and anti-apoptotic effects on cells. APC can directly modulate gene expression in human umbilical vein endothelial cells (HUVEC) with notable effects on anti-inflammatory and cell survival genes (Joyce et al., supra, 2001; Riewald et al., supra, 2002). Riewald et al. have shown this direct effect of APC on certain cells requires PAR-1 and EPCR (Riewald et al., supra, 2002), although they provided no data that related APC functional activity with PAR-1-signaling. Recombinant activated protein C (rAPC), similar to Xigris (Eli Lilly & Co.), is approved for treating severe sepsis and it may eventually have other beneficial applications. However, clinical studies have shown APC treatment to be associated with increased risk of serious bleeding. This increased risk of bleeding presents a major limitation of APC therapy. If APC's effects in sepsis can be attributed to its anti-inflammatory and cell survival activities, a compound that retains the beneficial anti-apoptotic or cytoprotective activity but has a less anticoagulant activity is desirable. SUMMARY OF THE INVENTION It is an object of this invention to provide variants (mutants) of recombinant APC and prodrugs (e.g., variants of recombinant protein C) as therapeutics or research tools for use in alleviating or preventing cell damage associated at least in part with apoptosis. It is also an object of this invention to provide a method of alleviating or preventing cell damage associated at least in part with apoptosis, especially in subjects at risk for or suffering from such cell damage. Another object of this invention is to provide a means for screening candidate mutants for use in accordance with the invention. The invention is directed to variants of recombinant APC and prodrugs (protein C variants) that provide reduced anticoagulant activity relative to anti-apoptotic activity compared to wild-type, and, therefore, have use as cytoprotective agents. Two examples of such recombinant APC mutants are KKK191-193AAA-APC (mutation of lysines 191, 192 and 193 to alanines) and RR229/230AA-APC (mutation of arginines 229 and 230 to alanines). As we demonstrate herein, these exemplary APC variants retain the desirable property of normal anti-apoptotic, cytoprotective activity but provide significantly reduced risk of bleeding, given their reduced anticoagulant activity. The APC and protein C variants of the invention provide a ratio of anti-apoptotic to anticoagulant activity greater than that of wild-type APC (i.e., >1.0). In one embodiment of the invention, a method of preventing or alleviating damage associated at least in part with apoptosis is provided. In a related aspect of this embodiment, a method of treating subjects at risk for cell damage associated at least in part with apoptosis is provided. These subjects include patients at risk of damage to blood vessels or tissue in various organs caused, at least in part, by apoptosis. At risk patients include, for example, those suffering (severe) sepsis, ischemia/reperfusion injury, ischemic stroke, acute myocardial infarction, acute or chronic neurodegenerative diseases, or those undergoing organ transplantation or chemotherapy, among other conditions. The APC variants and prodrugs of the invention should be useful in treating subjects who will benefit from APC protective activities that are independent of APC's anticoagulant activity. Prodrug embodiments of this invention may involve recombinant protein C variants that, following conversion of protein C to APC, exhibit reduced anticoagulant activity while retaining normal or near-normal cell protective activities. For example, variants of protein C, when activated, will have the desired ratio of anti-apoptotic to anticoagulant activity of greater than 1.0. In another embodiment of the invention, the APC mutants may be provided as therapeutics or in therapeutic compositions, to offer beneficial cytoprotective effects in cells, while carrying much less risk of bleeding. In yet another embodiment of the invention, methods of screening candidate recombinant APC variants having reduced anticoagulant activity, but retaining the beneficial cell protective and anti-inflammatory activities are provided. Given the risk of bleeding associated with wild type activated protein C, the APC mutants of this invention offer advantages over currently available wild-type recombinant APC. Therefore, APC mutants of the invention are expected to provide superior therapy, either alone or adjunctive to other agents, whenever APC might be used for its anti-inflammatory or anti-apoptotic (cell survival) activities, rather than purely for its anticoagulant activity. DESCRIPTION OF DRAWINGS FIGS. 1a-1b: Inhibition of staurosporine-induced (STS) apoptosis in Eahy926 endothelial cells by wild-type (rwt-APC) and variants of recombinant APC. FIG. 1a: dose-dependent reduction in STS-induced apoptosis expressed as percent apoptotic cells. FIG. 1b: dose-dependent reduction in STS-induced apoptosis with data normalized as percent apoptotic cells relative to control STS (no APC). FIG. 2: Ratio of anti-apoptotic (cytoprotective) activity to anticoagulant activity for wild-type and variants of recombinant APC. FIG. 3a-3b: Amidolytic and anticoagulant activity of rwt-APC and APC variants. a, Amidolytic activity of rwt-APC and APC variants against the small chromogenic substrate, S-2366. b, Anticoagulant activity of rwt-APC and APC variants determined using Activated Partial Thromboplastin Time (APTT) assays. Each point represents the mean±S.E.M. from at least three independent experiments. Symbols denote: □, rwt-APC; ∘, RR229/230AA-APC; ⋄, KKK191-193AAA-APC; ▪, S360A-APC. FIG. 4a-4c: Anti-apoptotic activity of rwt-APC and anticoagulantly impaired APC variants. a, Inhibition of staurosporine (STS)-induced apoptosis by APC (see Methods). Percentage of apoptotic endothelial cells observed in the absence of added APC (18% of all cells) was taken as 100%. Each point represents the mean±S.E.M. from at least three independent experiments. Symbols used denote: □, rwt-APC; ∘, RR229/230AA-APC; ⋄, KKK191-193AAA-APC; ▪, S360A-APC; •, no staurosporine. b, c, Reduction of activated caspase-3-positive cells by rwt-APC and APC variants (25 nM, 5 h) upon induction of apoptosis by staurosporine (2 μM, 4 h). b, Activated caspase-3-positive cells expressed as a percentage of the total number of cells present. As indicated by the “no STS”, thin line, approximately 2% of the endothelial cells were positive for activated caspase-3 in the absence of staurosporine. Each bar represents the mean±SEM of two to four independent experiments. c, Immunofluorescence analysis of activated caspase-3-positive cells using an activated caspase-3 specific antibody (red) and DAPI nuclear staining (blue). Columns represent identical fields. Original magnification was 200×. FIG. 5: Inhibition of apoptosis by rwt-APC and APC variants requires PAR-1 and EPCR. PAR-1 and EPCR-dependence for inhibition of staurosporine-induced endothelial cell apoptosis by rwt-APC and anticoagulantly impaired APC variants was studied using blocking antibodies against PAR-1 (open bars) (combination of WEDE-15 at 20 μg/ml and ATAP-2 at 15 μg/ml) or EPCR (cross-hatched bars)(rabbit anti-EPCR at 20 pg/ml). Solid bars represent “no antibodies added”. Cells were incubated with rwt-APC or APC variants (5 nM) 5 h prior to induction of apoptosis by staurosporine (10 μM, 1 h). Apoptosis was analysed by the uptake of Apopercentage dye and expressed as a percentage relative to the percentage of apoptotic cells observed in the absence of added APC (20% of all cells), which was set as 100%. The bar with “vertical lines” represents relative apoptosis in the absence of APC and staurosporine. Each bar represents the mean±S.E.M. from at least three independent experiments. FIG. 6: Cleavage of PAR-1 N-terminal TR33-62 peptide at Arg41 by rwt-APC and APC variants. HPLC was used to monitor TR33-62 cleavage by APC over time as disappearance of the TR33-62 peptide substrate peak (open symbols) and as appearance of the TR42-62 peptide product peak (solid symbols). Symbols denote: ▪,□: rwt-APC; •,∘: RR229/230AA-APC; ♦,⋄: KKK191-193AAA-APC and X,X: S360A-APC. The pooled data points of 3-5 independent experiments are shown for rwt-APC and the two anti-apoptotic APC variants. No cleavage was observed for the S360A-APC that lacks the active site Ser (X). Error bars indicate±S.E.M. DETAILED DESCRIPTION OF THE INVENTION Activated protein C (APC) has traditionally been regarded as an anticoagulant enzyme in the coagulation cascade, inhibiting thrombin formation and subsequent fibrin-clot formation by inactivating the cofactors factor Va and factor VIIIa (Esmon, supra, 2000a). However, APC also has the remarkable ability to reduce mortality in severe sepsis (Bernard et al., supra, 2001a; Bernard et al., Crit. Care Med., 29:2051-59, 2001b; Hinds, Brit. Med. J., 323:881-82, 2001; Kanji et al., Pharmacother., 21:1389-1402, 2001), while other anticoagulants such as antithrombin III and tissue factor pathway inhibitor have failed in this capacity (Warren et al., supra, 2001; Abraham et al., supra, 2001). This property of APC has peaked investigators' interest in the less extensively studied direct anti-inflammatory and anti-apoptotic activities attributed to APC (see, e.g., Cheng et al. Nat. Med., 9:338-42, 2003; Domotor et al., Blood, 101:4797-4801, 2003; Fernandez et al., Blood Cells Mol. Dis., 30:271-276, 2003; Esmon, J. Autoimmun., 15:113-116, 2000b). APC also has potential to protect the brain from damage caused by ischemic stroke (Cheng et al., supra, 2003; Esmon Thrombos Haemostas, 83:639-643, 2000c). A major concern for the use of APC as a therapeutic is an increased risk of bleeding complications (Bernard et al., supra, 2001a; Bernard et al., supra, 2001b) due to APC anticoagulant activity. The APC variants of this invention solve this problem by having reduced anticoagulant activity over endogenous APC or wild-type recombinant APC, while retaining beneficial anti-apoptotic activity. Differentiating the anticoagulant activity from the anti-apoptotic activity was the first step in solving this problem. We have focused in part on the role of EPCR in regulation of these activities. EPCR was originally discovered as a receptor capable of binding protein C and APC with equal affinities (Fukodome and Esmon, supra, 1995), and EPCR was shown to enhance the activation of protein C by the thrombin-thrombomodulin complex (Stearns-Kurosawa, et al., Proc. Nat'l Acad. Sci., USA, 93:10212-10216, 1996), apparently by optimizing the spatial localization of protein C for efficient activation by thrombomodulin-bound thrombin. Presumably EPCR binds APC to the endothelial surface and positions APC's active site proximate to the PAR-1 cleavage site at Arg41. Paradoxically, although EPCR function might be anticoagulant by stimulating protein C activation (Stearns-Kurosawa, et al., supra, 1996), APC anticoagulant activity is actually inhibited when APC is bound to EPCR (Regan et al., J. Biol. Chem., 271:17499-17503, 1996). Because binding of APC to EPCR is essential for APC's anti-apoptotic activity, we have concluded that the anti-apoptotic activity of APC is independent of its anticoagulant activity. We hypothesized that certain APC mutants could be generated which lack anticoagulant activity but retain anti-apoptotic activity. Such mutants could be therapeutically useful if they provided patients with direct cell survival activity without increased risks of bleeding. We have determined the structural elements of APC required for its anti-apoptotic activity, by assaying different forms of APC for their anti-apoptotic activity. The staurosporine-induced apoptosis was blocked by pretreatment of APC with an anti-APC monoclonal antibody or heat denaturation of APC, thereby establishing the specificity of APC's anti-apoptotic activity (Mosnier and Griffin, supra, 2003). APC-mediated inhibition of staurosporine-induced apoptosis was found to require APC's active site, since the inactive protein C zymogen, as well as an inactive APC mutant, in which the active site Ser was replaced by Ala, S360A-APC (Gale et al., Protein Sci., 6:132-140, 1997), were devoid of anti-apoptotic activity (Mosnier and Griffin, supra, 2003). This implies that the anti-apoptotic activity of APC is mediated by proteolysis. It was not known whether the APC-mediated inhibition of staurosporine-induced apoptosis (Joyce et al., supra, 2001) was dependent on PAR-1 and EPCR, until we demonstrated that inhibition of staurosporine-induced apoptosis by APC was dependent on PAR-1 and EPCR using a modified staurosporine-induced apoptosis model with EAhy926 endothelial cells (Mosnier and Griffin, supra, 2003). Inhibition of hypoxia-induced apoptosis in human brain endothelial cells also has been shown to require PAR-1 (Cheng et al., supra, 2003). Thus, consistent with the implication that APC's proteolytic active site is required for inhibition of apoptosis, preincubation of cells with blocking antibodies against PAR-1, but not against PAR-2, abolished APC-mediated inhibition of staurosporine-induced apoptosis (Mosnier and Griffin, supra, 2003). Furthermore, APC anti-apoptotic activity was abolished by an anti-EPCR antibody that blocks binding of APC to EPCR (Mosnier and Griffin, supra, 2003), and controls showed that this effect of the anti-EPCR antibody was neutralized by preincubation of the antibody with its peptide immunogen (Mosnier and Griffin, supra, 2003). Therefore, based on antibody blocking studies, PAR-1 and EPCR are required for APC to inhibit staurosporine-induced apoptosis of endothelial cells. This requirement for PAR-1 and EPCR for inhibition of staurosporine-induced apoptosis of EAhy926 endothelial cells also is consistent with the finding that these receptors are important for APC's anti-apoptotic activity in the setting of hypoxic brain microvascular endothelial cells (Cheng et al., supra, 2003). APC can cleave a synthetic extracellular N-terminal PAR-1 polypeptide at Arg41, the thrombin cleavage site (Kuliopulos et al., Biochemistry, 38:4572-4585, 1999). Cleavage of this synthetic PAR-1 polypeptide by APC is 5,000-times slower than by thrombin (Kuliopulos et al., supra, 1999). When thrombin cleaves PAR-1 at Arg41, potent cell signaling pathways might be initiated. It is likely that APC cleavage of PAR-1 at Arg41 initiates cell signals, including phosphorylation of MAP kinase (Riewald et al., supra, 2002). In brain endothelial cells subjected to hypoxia, an early result of APC signaling is the inhibition of increases in the levels of p53 (Cheng et al., supra, 2003). Previous studies suggest that APC directly alters the gene expression profiles of HUVEC so that several anti-apoptotic genes are upregulated (Joyce et al., supra, 2001; Riewald et al., supra, 2002) and that APC specifically downregulates levels of the pro-apoptotic factor, Bax, while it upregulates levels of the anti-apoptotic factor, Bcl-2, in brain endothelial cells (Cheng et al., supra, 2003). The specific alteration of the critical ratio of Bax/Bcl-2 is likely of key importance for apoptosis. Other than these events, little can be stated about the mechanisms for PAR-1-dependent APC signaling. It is interesting to note that the PAR-1 agonist peptide, TFLLRNPNDK, exhibited no protection from staurosporine-induced apoptosis of EAhy926 cells whereas this agonist provided partial rescue of brain endothelial cells from hypoxia-induced apoptosis, suggesting there are subtle, but significant, differences between APC's PAR-1-dependent anti-apoptotic activities in these two models. In vivo data are consistent with an important distinction between the anticoagulant and cell protective activities of APC. APC-induced neuroprotective effects in a murine ischemia/reperfusion injury model were observed at low APC doses that had no effect on fibrin deposition or on restoration of blood flow, indicating that APC's neuroprotective effects, at least in part, were independent of APC's anticoagulant activity (Cheng et al., supra, 2003). No inhibition of staurosporine-induced apoptosis of EAhy926 cells was observed with either PAR-1 or PAR-2 agonist peptides in the absence of APC. Moreover, thrombin, the archetype activator of PAR-1, did not inhibit staurosporine-induced apoptosis (Mosnier and Griffin, supra, 2003). The failure of these other activators of PAR-1 to provide cell survival activity indicates that the PAR-1-dependent anti-apoptotic effects of APC for staurosporine-induced apoptosis are specific for APC. Without being bound to a mechanism of action, we can speculate that when EPCR-bound APC cleaves and activates PAR-1, a significant modulation of PAR-1's intracellular signaling occurs, compared to signals triggered by thrombin or the PAR-1 agonist peptide. Another potential source of complexity may arise from the reported ability of EPCR to mediate nuclear translocation of APC (Esmon, supra, 2000c). The intracellular signals and pathways that cause inhibition of apoptosis by APC in various cell model systems remain to be elucidated. The physiological relevance of APC EPCR-dependent signaling via PAR-1 is further demonstrated by the APC-induced neuroprotective effects in a murine ischemia/reperfusion injury model that requires PAR-1 and EPCR (Cheng et al., supra, 2003). APC may act via the EPCR and PAR-1 on stressed brain endothelial cells, or the PAR-1 and the protease activated receptor-3 (PAR-3) on stressed neurons, to activate anti-apoptotic pathways and/or pro-survival pathways in these stressed and/or injured brain cells. In human brain endothelium in vitro and in animals in vivo (ischemic stroke and NMDA models), APC can inhibit the p53-signaling pro-apoptotic pathway in stressed or injured brain cells (International Patent Application No. PCT/US03/38764). EXAMPLES Structure-activity relationships of protein C and activated protein C may be studied using variant polypeptides produced with an expression construct transfected in a host cell with or without expressing endogenous protein C. Thus, mutations in discrete domains of protein C or activated protein C may be associated with decreasing or even increasing activity in the protein's function. To generate the APC variants and prodrugs of this invention, which provide a reduced risk of bleeding, i.e., reduced anticoagulant activity, but that retain useful cytoprotective activities, we have dissected anticoagulant activity from anti-apoptotic activity of APC by site-directed mutagenesis. Several amino acids in various surface loops of the protease domain of APC were identified that, when mutated to alanine, severely reduced anticoagulant activity but did not affect anti-apoptotic activity. These unexpected findings indicate that strategies aimed at reducing the anticoagulant activity while preserving the anti-apoptotic activity of APC are feasible and worthwhile, because they are likely to reduce bleeding complications associated with the current and future clinical uses of recombinant APC variants which retain cytoprotective activities. The structural basis of APC's anticoagulant activity has been centered primarily on the interaction of APC with factor Va. APC cleavage sites within factor Va are located at residues Arg306, Arg506 and Arg679 and cleavage of the former two correlates with loss of cofactor activity (Rosing and Tans, Thromb Haemost, 78:427-433, 1997; Kalafatis and Mann, J. Biol. Chem., 268:27246-57, 1993). Cleavage of factor Va at Arg506 occurs rapidly and usually precedes cleavage at Arg306. It is therefore considered the predominant site for the initial inactivation of the factor Va molecule (Norstrom et al., J. Biol. Chem., 278:24904-1133, 2003; Nicolaes, et al., J. Biol. Chem., 270:21158-66, 1995). The interaction of APC with the Arg506 cleavage site in factor Va has been extensively characterized and as a result a factor Va binding site on the positively charged surface of the protease domain of APC has been defined (Gale et al., Blood, 96:585-593, 2000; Gale et al., J. Biol. Chem. 277:28836-28840, 2002; Friedrich et al., J. Biol. Chem., 276:23105-08, 2001a; Knobe et al., Proteins, 35:L218-234, 1999; Shen et al., Thromb. Haemost., 82:72-79, 1999). This positive exosite for factor Va binding on APC is generally located in the same area as the anion binding exosite I of thrombin and is comprised of residues in loop 37, which contains protein C residues 190-193 (equivalent to chymotrypsin (CHT) residues 36-39), the calcium ion-binding loop containing residues 225-235 (CHT 70-80) and the autolysis loop containing residues 301-316 (CHT 142-153) (Mather et al., EMBO J., 15:6822-31, 1996). In addition, mutations in loop 60, containing protein C residues 214-222 (CHT 60-68) have little effect on factor Va inactivation by APC although this loop is implicated in interactions with thrombomodulin and heparin (Gale et al., supra, 2002; Friedrich et al., supra, 2001a; Knobe et al., supra, 1999; Shen et al., supra, 1999; Friedrich et al., J. Biol. Chem., 276:24122-28, 2001b). Gale et al. (supra, 2002) have demonstrated that mutations in the surface loops of APC affect its anticoagulant activity. APC mutants KKK191-193AAA (loop 37), RR229/230AA (calcium loop), RR306/312AA (autolysis loop), RKRR306-314AAAA (autolysis loop) were shown to have 10%, 5%, 17%, and less than 2% of the anticoagulant activity of native APC, respectively. Subsequently, we found that these APC mutants with reduced anticoagulant activity (i.e., KKK191-193AAA, RR229/230AA (Mosnier et al. (Blood epup, 2004)) and RR306/312AA (Mosnier & Griffin, unpublished observations)) retain the anti-apoptotic activity of APC in staurosporine model of apoptosis. To demonstrate that we could distinguish between structural features of APC necessary for anticoagulant activity versus cell-protective activity, we studied recombinant variant forms of APC that had severely reduced anticoagulant activity. Using double, triple and quadruple combinations of site-directed mutations in the factor Va binding site of APC, we constructed a set of APC variants with severely decreased anticoagulant activity but with essentially unchanged enzymatic activity for small peptide (chromogenic) substrates (Gale et al., supra, 2000; Gale et al., supra, 2002). Anticoagulant activity was determined in a dilute prothrombin clotting assay (Gale et al., supra, 2002). The cytoprotective (anti-apoptotic) activity of APC mutants was tested in a staurosporine-induced model of apoptosis with EAhy926 endothelial cells, with the modifications described by Mosnier and Griffin (supra, 2003). It was discovered that APC-mediated inhibition of staurosporine-induced apoptosis required APC's active site, since the inactive APC mutant in which the active site serine360 was replaced by alanine (S360A-APC, see Table 1) (Gale et al., supra, 1997), was devoid of anti-apoptotic activity (Mosnier and Griffin, supra, 2003) (FIGS. 1a and 1b). Recombinant APC inhibition of staurosporine-induced apoptosis in Eahy926 endothelial cells was determined by Apopercentage staining. Inhibition of apoptosis by recombinant wild-type APC (rwt-APC) was dose-dependent (FIG. 1a). Half-maximum inhibition of staurosporine-induced apoptosis was achieved at 0.24 nM rwt-APC, using a 5 hour preincubation of APC with cells before addition of staurosporine. Note the absence of apoptotic activity in the S360A mutant (FIG. 1b). The mutations described in examples 1-3 and their % activities relative to wild-type are indicated in Table 1. Also indicated in Table 1 is the ratio of anti-apoptotic (cytoprotective) activity to anticoagulant activity for each of wild-type APC and mutant APC of examples 1-3, as described in example 4. TABLE 1 Overview of APC mutants (anticoagulant activity determined by dilute prothrombin time (PT)) anticoagulant FVa inact. wt-APC sequence cytoprotective activity Cytoprotective- Arg506 Amydolytic (underlined are activity (% wt- anticoagulant (Arg306) activity1 T½ mutant mutated to alanine) (% wt-APC) APC)1 ratio (% wt-APC)1 (% wt-APC) (min) rwt-APC n/a 100% 100% 1.0 100% 100% 21.4 (100%) 229/230- 225-EYDLRRWEKWE- 89% 6.6% 13.5 25% (110%) 115% 27.6 APC 235 3K3A-APC 189-DSKKKL-194 120% 15% 8.0 11% (67%) 134% 20.7 306-314- 305-SREKEAKRNRT-315 <1% 1.6%2 0.6 1.4% (16%) 75.6% 46.2 APC 1from references (Gale et al., 1997; Gale et al., 2000; Gale et al., 2002); See text and Methods for more information. 2determined by APTT instead of dilute PT n/a: not applicable; rwt-APC, recombinant wild-type-APC; 229/230-APC, RR229/230AA-APC; 3K3A-APC, KKK191-193AAA-APC; 306-314-APC, RKRR306/311/312/314AAAA-APC. Example 1 Replacing the two arginine residues, Arg229 and Arg230, in the calcium-binding loop of APC with alanine residues resulted in a form of APC RR229/230AA-APC (229/230-APC), see Table 1) with only 6.6% residual anticoagulant activity. This reduction in anticoagulant activity of RR229/230AA-APC was primarily due to reduced inactivation of factor Va (FVa) at Arg506 whereas cleavage of factor Va at Arg306 was much less affected. The dose-dependence for inhibition of apoptosis by RR229/230AA-APC (FIGS. 1a and 1b) was similar to that of recombinant wild type (rwt)-APC. Half-maximum inhibition of staurosporine-induced apoptosis by RR229/230AA-APC was achieved at 0.27 nM. This example demonstrates that the anticoagulant activity of APC is not required for the cytoprotective (anti-apoptotic) activity of APC. Example 2 In this example, an APC mutant in which three consecutive lysine residues in loop 37 were replaced with three alanines KKK191-193AAA-APC (3K3A-APC), see Table 1) displayed only 15% residual anticoagulant activity as determined in a dilute prothrombin clotting assay (Gale et al., supra, 2002). The reduction in anticoagulant activity of KKK191-193AAA-APC was due to severely reduced cleavage of factor Va at Arg506 (11% of rwt-APC), whereas inactivation of factor Va at Arg306 was only moderately affected (67% of rwt-APC) (Table 1). Remarkably, as seen in FIGS. 1a and 1b, the anti-apoptotic activity of KKK191-193AAA-APC was similar to that of rwt-APC with half-maximum inhibition of staurosporine-induced apoptosis at 0.20 nM. Example 3 In this example, four out of the five basic amino acids in the so-called autolysis loop of APC were replaced by alanine residues, resulting in a form of APC RKRR306/311/312/314AAAA-APC (306-314-APC, see Table 1) having only 1.6% residual anticoagulant activity, as determined by the activated partial thromboplastin time (APTT) [765]. The reduction in anticoagulant activity of RKRR306/311/312/314AAAA-APC was due to severely reduced cleavage of factor Va at Arg506 (1.4% of rwt-APC) whereas inactivation of factor Va at Arg306 was only moderately affected (16% of rwt-APC). The RKRR306/311/312/314AAAA-APC mutant was severely deficient in cytoprotective (anti-apoptotic) activity (FIGS. 1a and 1b), with inhibition of staurosporine-induced apoptosis requiring much higher concentrations of this mutant APC compared to rwt-APC or the other two APC mutants, RR-229/230AA-APC and KKK191-193AAA-APC. Example 4 The ratio of anti-apoptotic activity to anticoagulant activity was calculated for rwt-APC and for each APC mutant of examples 1-3 (see Table 1), based on the anti-apoptotic activity data in FIG. 1 and published anticoagulant activities (Gale et al., supra, 2000; Gale et al., supra, 2002). The ratio of activities for rwt-APC is defined as 1.0. These ratios, as shown in FIG. 2, indicate that APC mutants with mutations in certain residues in certain protease domain surface loops can exhibit 8-times to 14-times greater anti-apoptotic activity relative to anticoagulant activity. The two mutants, KKK191-193AAA-APC and RR229/230AA-APC, would be expected to exhibit anti-apoptotic or cytoprotective activity comparable to rwt-APC while having an 8-fold to 14-fold reduced risk of bleeding because of the reduction in anticoagulant activity. The ratio of anti-apoptotic to anticoagulant activity of a recombinant APC mutant may be used to identify variants of recombinant APC of this invention having therapeutic potential. A ratio of >1.0 is indicative of a therapeutic recombinant APC mutant having cytoprotective benefits and reduced risks of bleeding for a subject in need of acute or prophylactic treatment for cell damage, in accordance with this invention. Preferably, a therapeutic variant of recombinant APC would have a ratio of anti-apoptotic activity to anticoagulant activity of greater than about 2. More preferably, said ratio would be greater than about 4. Most preferably, said ratio would be greater than about 8. Prodrug embodiments of this invention may involve recombinant protein C variants that, following conversion of protein C to APC either in vitro or in vivo, exhibit reduced anticoagulant activity while retaining normal or near-normal cell protective activities, i.e., have a ratio of anti-apoptotic:anticoagulant activity greater than 1.0. Preferably, the prodrugs of the invention may be converted to APC variants that have a ratio of anti-apoptotic activity to anticoagulant activity that is greater than about 2, more preferably the ratio is greater than about 4 or most preferably the ratio is greater than about 8. The invention comprises several embodiments which are described below. In one embodiment, the variants of APC of the invention may be used in effective doses to provide cytoprotection to cells at risk for undergoing apoptotic cell death or stress-induced injury either in vivo or in vitro. In an aspect of this embodiment the APC variants may be administered in therapeutic doses to subjects who could benefit from APC's cytoprotective activities that are independent of the anticoagulant activity. Such subjects comprise patients at risk for damage to blood vessels or other tissue organs, which damage is caused at least in part by apoptosis. The risk for cell damage may be the result of any one or more of sepsis, ischemia/reperfusion injury, stroke, ischemic stroke, acute myocardial infarction, acute neurodegenerative disease, chronic neurodegenerative disease, organ transplantation, chemotherapy, or brain radiation injury. These causes of cell damage are not intended in any way to limit the scope of the invention, as one skilled in the art would understand that other diseases or injuries also may put cells at risk for damage caused at least in part by apoptosis. The effective doses or therapeutic doses will be those that are found to be effective at preventing or alleviating cell damage caused at least in part by apoptosis. In another aspect of this embodiment, the variants of the invention may be applied to cells or tissue in vitro or in situ in vivo. In another embodiment, the variants of APC or prodrugs of the invention may be used to formulate pharmaceutical compositions with one or more of the utilities disclosed herein. The therapeutic compositions may be administered in vitro to cells in culture, in vivo to cells in the body, or ex vivo to cells outside of a subject, which may then be returned to the body of the same subject or another. The cells may be removed from, transplanted into, or be present in the subject (e.g., genetic modification of endothelial cells in vitro and then returning those cells to brain endothelium). The prodrugs would be expected to be capable of being converted to APC in situ. Candidate agents may also be screened in vitro or in vivo to select those with desirable properties. The cell may be from the endothelium (e.g., an endothelial or smooth muscle cell or from the endothelium of a brain vessel). Therapeutic compositions comprising the variant APC of the invention may be provided in dosage form. In one aspect of this embodiment, the therapeutic compositions of the invention may further comprise a pharmaceutically acceptable carrier and may still further comprise components useful for delivering the composition to a subject's brain. Such pharmaceutical carriers and delivery components are known in the art. Addition of such carriers and other components to the composition of the invention is well within the level of skill in this art. For example, a permeable material may release its contents to the local area or a tube may direct the contents of a reservoir to a distant location of the brain. The pharmaceutical compositions of the invention may be administered as a formulation, which is adapted for direct application to the central nervous system, or suitable for passage through the gut or blood circulation. Alternatively, pharmaceutical compositions may be added to the culture medium. In addition to active compound, such compositions may contain pharmaceutically-acceptable carriers and other ingredients known to facilitate administration and/or enhance uptake. It may be administered in a single dose or in multiple doses, which are administered at different times. A unit dose of the composition is an amount of APC mutants provides cytoprotection, inhibits apoptosis or cell death, and/or promotes cell survival but does not provide a clinically significant anticoagulant effect, a therapeutic level of such activity, or has at least reduced anticoagulant activity in comparison to previously described doses of activated protein C. Measurement of such values are within the skill in the art: clinical laboratories routinely determine these values with standard assays and hematologists classify them as normal or abnormal depending on the situation. Examples of how to measure such values are described below. The pharmaceutical compositions of the invention may be administered by any known route. By way of example, the composition may be administered by a mucosal, pulmonary, topical, or other localized or systemic route (e.g., enteral and parenteral). In particular, achieving an effective amount of activated protein C, prodrug, or functional variant in the central nervous system may be desired. This may involve a depot injection into or surgical implant within the brain. “Parenteral” includes subcutaneous, intradermal, intramuscular, intravenous, intra-arterial, intrathecal, and other injection or infusion techniques, without limitation. Suitable choices in amounts and timing of doses, formulation, and routes of administration can be made with the goals of achieving a favorable response in the subject (i.e., efficacy or therapeutic), and avoiding undue toxicity or other harm thereto (i.e., safety). Administration may be by bolus or by continuous infusion. Bolus refers to administration of a drug (e.g., by injection) in a defined quantity (called a bolus) over a period of time. Continuous infusion refers to continuing substantially uninterrupted the introduction of a solution into a blood vessel for a specified period of time. A bolus of the formulation administered only once to a subject is a convenient dosing schedule, although in, the case of achieving an effective concentration of activated protein C in the brain more frequent administration may be required. Treatment may involve a continuous infusion (e.g., for 3 hr after stroke) or a slow infusion (e.g., for 24 hr to 72 hr when given within 6 hr of stroke). Alternatively, it may be administered every other day, once a week, or once a month. Dosage levels of active ingredients in a pharmaceutical composition can also be varied so as to achieve a transient or sustained concentration of the compound or derivative thereof in a subject and to result in the desired therapeutic response. Thus, “therapeutic” refers to such choices that involve routine manipulation of conditions to achieve a desired effect (e.g., inhibition of apoptosis or cell death, promotion of cell survival, cytoprotection, neuroprotection, or combinations thereof). The amount of mutant protein C or mutant activated protein C administered to subjects may be higher than doses of recombinant protein C or activated protein C, if necessary for maximal cytoprotection, because of the reduced risk of bleeding. In this manner, “therapeutic amount” refers to the total amount of activated protein C variant or protein C variant that achieves the desired cytoprotective effect, but with reduced risk for bleeding due to reduced anticoagulant activity (for bolus administration, e.g., 2 mg/kg or less, 1 mg/kg or less, 0.5 mg/kg or less, 0.04 mg/kg or less, 0.03 mg/kg or less, 0.02 mg/kg or less, 0.01 mg/kg or less, 0.005 mg/kg or less, depending on the species of the subject or disease to be treated). The therapeutic amount may be about 0.01 mg/kg/hr to about 1.1 mg/kg/hr, for example, administered by continuous infusion over 4 hour to 96 hour, to as little as about 0.01 mg/kg/hr to about 0.10 mg/kg/hr for about 24 hours. Preferably, the therapeutic dose would be administered by continuous infusion for about 4 to about 72 hours. More preferably, by continuous infusion for about 4 to about 48 hours. More preferably, by continuous infusion for about 12 to about 48 hours. More preferably, by continuous infusion for about 12 to about 36 hours. More preferably, by continuous infusion for about 4 to about 36 hours. More preferably, by continuous infusion for about 12 to about 24 hours. Most preferably, by continuous infusion for about 24. The therapeutic amount may be based on titering to a blood level amount of APC of about 0.01 μg/ml to about 1.6 μg/ml, preferably from about 0.01 μg/ml to about 0.5 μg/ml. It is also within the skill of the art to start doses at levels lower than required to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved. It is likewise within the skill of the art to determine optimal concentrations of variants to achieve the desired effects in the in vitro and ex vivo preparations of the invention, e.g., about 1-100 nM. In yet another embodiment, a method of screening candidate agents to identify other variants of recombinant APC having therapeutic potential in accordance with the invention is provided. One aspect of this embodiment comprises mutating the recombinant APC or protein C at any surface loop of the protease domain and determining the variant APC's anticoagulant and cytoprotective activities in assays as described. The method of the embodiment further comprises measuring the anticoagulant activity of said mutated recombinant activated protein C; measuring the anti-apoptotic activity of said mutated recombinant activated protein C; calculating the ratio of anti-apoptotic activity to anticoagulant activity; identifying the recombinant activated protein C as potentially therapeutic if said ratio is greater than 1.0. Preferably, the ratio is greater than about 2, more preferably the ratio is greater than about 4, most preferably the ratio is greater than about 8. Where the candidate agent is a prodrug, the prodrug may comprise a protein C variant, which is capable of being converted to an activated protein C variant either in vivo or in vitro. To screen the candidate protein C variant for desirable properties in accordance with the invention, the protein C variant would be converted to the activated form (APC) prior to measuring activities. In another aspect of this embodiment, a library of candidate agents is selected which are variants of recombinant APC or protein C having at least one mutation at a residue in a protease domain of a surface loop selected from the group consisting of loop 37, calcium loop, and autolysis loop. The method comprises converting the protein C variant to activated protein C variant; determining anti-apoptotic activity of said candidate agents in one or more stressed or injured cells by exposing said cells to an apoptotic-inducing concentration of staurosporine in the presence of an amount of a candidate agent; determining anticoagulant activity of said candidate agents in one or more stressed or injured cells exposing cells to same amount of the same candidate agent as in (b), and performing a dilute prothrombin time clotting assay; calculating the ratio of the anti-apoptotic activity determined in (a) to the anticoagulant activity of (b); and selecting candidate agents having an anti-apoptotic:anticoagulant activity ratio greater than 1.0. Preferably, the ratio is greater than about 2, more preferably the ratio is greater than about 4, most preferably the ratio is greater than about 8. Other permutations of this basic scheme of screening for candidate agents are within the ordinary skill in the art and are encompassed by the invention. Examples of such permutations non-exclusively include using other methods of inducing apoptosis and other tests for measuring apoptotic activity and anticoagulant activity. Methods Protein C Activation Recombinant forms of protein C can be produced with a selected chemical structure (e.g., native, mutant, or polymorphic). As an illustration, a gene encoding human protein C is described in U.S. Pat. No. 4,775,624 and can be used to produce recombinant human protein C as described in U.S. Pat. No. 4,981,952. Human protein C can be recombinantly produced in tissue culture and activated as described in U.S. Pat. No. 6,037,322. Natural human protein C can be purified from plasma, activated, and assayed as described in U.S. Pat. No. 5,084,274. The nucleotide and amino acid sequence disclosed in these patents may be used as a reference for protein C. In the above examples of this invention, recombinant wild-type APC (wt-APC), RR229/230AA-APC (229/230-APC), KKK191/192/193AAA-APC (3K3A-APC), RKRR306/311/312/314AAAA-APC (306-314-APC) and S360A-APC were prepared as described (Gale et al., supra, 1997; Gale et al., supra, 2000; Gale et al., supra, 2002). Protein C was activated by thrombin (3281 U/mg, Enzyme Research Labs, South Bend, Ind.). Protein C in HBS (HEPES buffered saline, 50 mM HEPES, 150 mM NaCl) with 2 mM EDTA and 0.5% bovine serum albumin (BSA), pH 7.4, at a concentration of 600 μg/mL was incubated for 2.5 hours with 12 μg/mL thrombin at 37° C., followed by the addition of 1.1 units of hirudin (Sigma, St Louis, Mo.) per unit of thrombin to inactivate the thrombin. Controls were done in amidolytic assays, APTT clotting assays and FVa inactivation assays to verify that the thrombin and hirudin used had no effect on subsequent assays. A “mutation” refers to one or more changes in the sequence of polynucleotides and polypeptides as compared to native activated protein C, and has at least one function that is more active or less active, an existing function that is changed or absent, a novel function that is not naturally present, or combinations thereof. Active-Site Titration of APC All APC mutants were quantitated using an active site titration adapted from Chase and Shaw (Biochem. Biophys. Res. Commun., 29:508-514, 1967) using APC at approximately 8 μM in HBS and p-nitrophenol-guanidino benzoate at 0.1 mM with an extinction coefficient for p-nitrophenol of 11400 M−1 cm−1 calculated for pH 7.4. Kinetic Analysis of APC Michaelis constants (Km) and catalytic rate constants (kcat) for the chromogenic substrate, Pefachrome PCa (Pentapharm, Basel, Switzerland), were determined by varying substrate concentration from 1.43 mM to 0.0446 mM in HBS, 0.5% BSA, 5 mM CaCl2, pH 7.4 with APC at 5.7 nM. Michaelis constants were derived using Eadie-Hofstee plots. Alternatively, the 5 mM CaCl2 was replaced with 5 mM EDTA for similar determinations. Color development was measured with an Optimax microplate reader (Molecular Devices, Sunnyvale, Calif.) (Mesters et al., J. Biol. Chem., 266:24514-19, 1991). Cell Culture EAhy926 endothelial cells were obtained from Dr. C. J. S. Edgell (University of North Carolina, Chapel Hill N.C.) and were maintained in DMEM high glucose (Gibco, Grand Island, N.Y.) with 10% fetal bovine serum (Omega Scientific, Tarzana, Calif.), 100 U/ml penicillin G sodium (Gibco), 100 μg/ml streptomycin sulphate (Gibco) and 2 mM glutamine (Gibco) at 37° C. in a humid atmosphere containing 5% CO2 in air as described (Edgell et al., Proc. Nat'l Acad. Sci., USA, 80:3734-3737, 1983). Apoptosis Assay Staurosporine-induced apoptosis of endothelial cells was initiated using our modifications (Mosnier and Griffin, supra, 2003) of the previously described assay (Joyce et al., supra, 2001). The modifications involved culturing the cells on gelatin-coated coverslips, changing the staurosporine concentration and optimizing the APC preincubation times before addition of staurosporine as described below. Staurosporine, an ATP analogue and inhibitor of protein kinase C (PKC), is a well known and potent inducer of apoptosis. Apopercentage dye is a measurement of expression of phosphatidylserine on the outside surface of the cell membrane and is therefore similar to what is measured by traditional annexin-V labeling. The transfer of phosphatidylserine to the outside surface of the cell membrane permits the unidirectional transport of the Apopercentage dye inside the cell where it is retained and accumulates. The accumulated dye has a red/purple color and is visible under a conventional microscope (Joyce et al., supra, 2001; Mosnier and Griffin, supra, 2003). We used this dye to monitor apoptosis. Alternatively, cells may be incubated with the apoptosis specific dye, YO-PRO-1 (10 μM, 5 min) (Molecular Probes, Eugene, Oreg.) as described (Idziorek et al., J. Immunol. Methods, 185:249-258,1995) or for 20 min with the synthetic substrate for caspase 3-like enzymes, DEVD-amc (Calbiochem, San Diego, Calif.). Staurosporine induced a time-dependent and concentration-dependent apoptosis in EAhy926 endothelial cells, as determined by Apopercentage staining (data not shown). Briefly, 12 mm round coverslips (Fisherbrand, Pittsburgh, Pa.) were acid washed, rinsed with distilled water and 95% ethanol, dipped 10× in gelatin (0.5% gelatin provided with the Apopercentage dye) until an homogenous drop was formed and air dried. EAhy926 cells were grown to confluency on gelatin-coated coverslips in 24 well plates and incubated with APC for 5 hours prior to apoptosis induction. After the preincubation with the various proteins, apoptosis was induced by addition of staurosporine (Calbiochem, San Diego, Calif.) to a final concentration of 10 μM in the presence of the Apopercentage dye (Biocolor, Belfast, N. Ireland) diluted to a final concentration of 1/20 of the provided stock solution per the manufacturer's instructions. After 1 hour incubation at 37° C. in a humid atmosphere containing 5% CO2 in air the cells were washed in phosphate buffered saline (PBS) and 500 μl of DMEM high glucose without phenol red (Gibco, Grand Island, N.Y.) with 5% fetal bovine serum (Omega Scientific, Tarzana, Calif.), 100 U/ml penicillin G sodium (Gibco), 100 mg/ml streptomycin sulphate (Gibco) and 2 mM glutamine (Gibco) added to the cells. Cells were photographed immediately after washing, using a Zeiss IM inverted microscope connected to a Spot QE digital camera. An average of 4 fields at 100× magnification were photographed per coverslip and numbers of apoptotic cells were counted using the image analysis software Cell Counter (written by Dr. L. O. Mosnier, The Scripps Research Institute). For each experiment representative fields of the cells were photographed using phase contrast and the total number of cells present was counted. The percentage of apoptosis is expressed as the number of apoptotic cells relative to the total number of cells. Repeated control experiments were performed (MTT based assay, Celltiter 96 Aqueous non-radioactive cell proliferation assay, Promega, Madison, Wis.) to ascertain that the cells did not become detached. In addition, on occasions when disruption of the confluent cell layer was observed, the data point was excluded from further analysis and repeated. Clotting Assays Dilute prothrombin time clotting assays were performed, as follows. Plasma (50 μL) was incubated with 50 μL of APC in HBS with 0.5 % BSA at APC concentrations from 8 to 32 nM (2.7-11 nM final concentration) for 3 min at 37° C. Then clotting was initiated by adding 50 μL Innovin (Dade Behring Inc., Newark, Del.) diluted 1:60 in HBS, 0.5% BSA, 25 mM CaCl2. The clotting time was measured using an ST4 coagulometer (Diagnostica Stago, Asnieres, France). For APTT clotting assays, 50 μL of plasma was mixed with 50 μL of APTT reagent (Platelin LS, Organon Technika Corp, Durham, N.C.) and preincubated for at 37° C. for 3 minutes. Then 2 μL APC was added followed by 50 μL of HBS, 0.5% BSA, 5 mM CaCl2. The clotting time was recorded using an ST4 coagulometer (Diagnostica Stago, Asnieres, France). APC Inactivation APC inactivation by serpins present in plasma was measured essentially according to the protocol of Heeb et al (J. Biol. Chem., 265:2365-2369, 1990). Briefly, either human plasma or a mix of pure serpin inhibitors (PCl and/or α1-antitrypsin) was preincubated at 37° C., then APC was added. At selected times aliquots were removed and assayed for APC activity with an APC specific chromogenic substrate. Factor Va Inactivation Inactivation of FVa was measured as follows. A mixture of 1 nM FVa with 25 μM phospholipid vesicles was made in 50 mM HEPES, pH 7.4, 100 mM NaCl, 0.5% BSA, 5 mM CaCl2, 0.1 mM MnCl2. Inactivation was initiated by the addition of APC. One microliter aliquots were removed at time points and added to 40 μL containing 1.25 nM factor Xa (FXa) with 31 μM phospholipid vesicles, followed by addition of 10 μL 3 μM prothrombin (final concentrations: 1 nM FXa, 20 PM FVa, 25 μM phospholipid vesicles and 0.6 μM prothrombin). After 2.5 min a 15 μL aliquot of this mixture was quenched by addition to 55 μL HBS containing 10 mM EDTA, 0.5% BSA, pH 8.2. Chromogenic substrate CBS 34-47 (Diagnostica Stago, Asnieres, France) was added and the rate of thrombin formation was assessed by measuring the change in absorbance at 405 nm. Curve fitting of these pseudo-first order time courses of FVa inactivation was done according to Nicolaes et al. (supra, 1995) using equation 1: Va t = Va 0 · ⅇ - ( k 506 + k 306 ′ ) · t + B · Va · k 506 · ⅇ ( - k 306 · t ) ( k 506 + k 306 ′ - k 306 ) · ( 1 - ⅇ - ( k 506 + k 306 ′ - k 306 ) · t ) equation 1 Those skilled in the art will recognize other disease states and/or symptoms, which might be treated and/or mitigated by the present invention. For example, the present invention may be used to treat myocardial infarction, other heart diseases and their clinical symptoms, endothelial injury, adult respiratory distress syndrome (ARDS), and failure of the liver, kidney, or central nervous system (CNS). There are many other diseases which benefit from the methodologies of the present invention such as for example, coronary arterial occlusion, cardiac arrhythmias, congestive heart failure, cardiomyopathy, bronchitis, neurotrauma, graft/transplant rejection, myocarditis, diabetic neuropathy, and stroke. Life threatening local and remote tissue damage occurs during surgery, trauma, and stroke when major vascular beds are deprived for a time of oxygenation (ischemia) then restored with normal circulation (reperfusion). Cell death and tissue damage can lead to organ failure or decreased organ function. The compositions and methodologies of the present invention are useful in treatment of such injury or prevention thereof. In summary, two examples of the variants of recombinant APC mutants of this invention, namely KKK191-193AAA-APC and RR229/230AA-APC are provided, that have substantial reductions in anticoagulant activity but that retain normal or near-normal levels of anti-apoptotic activity. The invention encompasses APC variants such as these, which have the highly desirable property of a high ratio of anti-apoptotic to anticoagulant activity. The invention further encompasses variants having more modest, yet still beneficial, ratios of anti-apoptotic to anticoagulant activity; such variants also would be expected to be cytoprotective while having significantly reduced risk of bleeding. The invention is not limited to variants of APC, but also includes protein C mutants which are capable of yielding desirable APC mutants, i.e., those that would have the same desirable activity ratios. The invention also is not limited to mutations on loop 37, calcium loop, or autolysis loop; the invention encompasses mutations of residues on other surface loops of the protease domain that produce the desired cytoprotective to anticoagulant ratio. Thus, APC and protein C variants of the invention are expected to be useful for therapy for subjects who will benefit from APC protective activities that are independent of APC's anticoagulant activity. Subjects would include patients at risk of damage from apoptosis to blood vessels or tissue in various organs. More specifically, but not exclusively, these subjects will include, for example, those suffering severe sepsis, ischemia/reperfusion injury, ischemic stroke, acute myocardial infarction, acute or chronic neurodegenerative diseases and organ transplantation, among other conditions. Example 5 Methods This example includes refined data from Table 1 incorporating additional experiments that are averaged in and improved data analysis along with data for the variant S360A-APC. Furthermore, the anticoagulant data was collected using the APTT assay instead of the PT assay (as mentioned in Table 2). Therefore, this refined data is presented as Table 2. This example also includes more detailed analysis of the amidolytic, anticoagulant and anti-apoptotic activities of the variants of APC (FIGS. 3-6). For this example, the following methods were employed. Human alpha-thrombin was purchased from Enzyme Research Laboratories (South Bend, Ind.). Normal human citrate-anticoagulated plasma was from George King Bio-Medical, Inc. (Overland Park, Kans.). The chromogenic substrate L-Pyroglutamyl-L-prolyl-L-arginine-p-Nitroaniline hydrochoride (S-2366) was obtained from Chromogenix (Franklin, Ohio). Preparation of Recombinant Activated Protein C Mutant protein C expression vectors were constructed and recombinant protein C mutants were purified from conditioned media as described (Gale et al., supra, 2002; Gale et al., supra, 1997). Purified protein C was activated by thrombin (Gale et al., supra, 2002; Gale et al., supra, 1997). Briefly, Protein C in HBS (50 mM HEPES, 150 mM NaCl) with 2 mM EDTA and 0.5% BSA, pH 7.4, at a concentration of 600 μg/ml was incubated for 2.5 h with 12 μg/ml thrombin at 37° C. followed by the addition of 1.1 units of hirudin per unit of thrombin to inactivate the thrombin. Subsequently, thrombin was removed by anion-exchange chromatography with NaCl gradient elution (Yan et al., Biotechnology, 8:655-661, 1990). Residual thrombin, as determined by fibrin clotting, accounted for less than 0.00025% (mol thrombin/mol APC) of the protein. Concentrations of rwt-APC and APC mutants were determined by active-site titration adapted from Chase and Shaw (Chase and Shaw, supra, 1967) using APC at ˜8 μM in HBS and p-nitrophenol-guanidino benzoate at 0.1 mM and using an extinction coefficient for p-nitrophenol of 11,400 M−1cm−1 (at pH 7.4) as described (Gale et al., supra, 2002). The concentration of S360A-APC was determined by Asserachrom Protein C ELISA from American Bioproducts (Parsippany, N.J.) (Gale et al., supra, 1997). APC Activity Assays Amidolytic (S-2366) assays were performed as described (Gale et al., supra, 2000; Gale et al., supra, 1997). APTT clotting time assays were performed according to the following procedure. Plasma (50 μl) was incubated for 1 min with kaolin/cephalin (50 μl) (C.K. Prest 2, Diagnostica Stago, Parsippany, N.J.) at 37° C., and then 25 μl APC in HBS with 0.5% BSA was added at final APC concentrations from 0.5 nM-32 nM and incubated for an additional 3 min. Clotting was then initiated by adding 50 μl of 50 mM CaCl2 in HBS and the clotting time was recorded using an Amelung KC 4a micro coagulometer (Sigma Diagnostics, St Louis, Mo.). APC's cytoprotective effects were determined in assays of staurosporine-induced endothelial cell (EA.hy926) apoptosis as described (Mosnier and Griffin, supra, 2003). APC (0.16-100 nM) was incubated with cells for 5 h prior to induction of apoptosis by staurosporine (10 μM, 1 h) unless otherwise indicated, and apoptosis was assessed by Apopercentage dye from Biocolor (Belfast, N. Ireland) which measures phosphatidylserine translocation to the outside surface of the cell membrane. Blocking antibodies against PAR-1 (WEDE-15 and ATAP-2 kindly provided by Dr L. Brass) and against EPCR (Zymed) were used as described (Mosnier and Griffin, supra, 2003). For activated caspase-3 immunofluorescence staining and DAPI nuclear staining (5 μg/ml) of staurosporine-treated (2 μM, 4 h) EA.hy926 endothelial cells that had been incubated with APC (25 nM, 5 h) prior to apoptosis induction, the manufacturer's instructions were followed using a rabbit anti-activated caspase-3 antibody (Promega) and Alexa-fluor-568 labeled secondary goat anti-rabbit (Molecular Probes). PAR-1 Peptide Cleavage. The interactions of rwt-APC and APC variants (500 nM) with PAR-1 N-terminal tail peptide (TR33-62) were studied using a synthetic peptide representing PAR-1 residues 33-62 (Bio Synthesis Inc., Lewisville, Tex.). The peptide sequence was A33TNATLDPR41SFLLRNPNDKYEPFWEDEEKN62 and was cleaved by APC between Arg41 and Ser42. The substrate peptide and the two peptide products of thrombin or APC cleavage at Arg41 (TR33-41 and TR42-62) were resolved and analysed by reverse phase HPLC and quantified essentially as described (Arosio et al., Biochemistry, 39:8095-8101, 2000). All TR33-62 cleavage experiments with APC contained 5 nM hirudin to assure that the observed cleavage was not due to thrombin contamination. Results The anti-apoptotic, anticoagulant and amidolytic activities of RR229/230AA-APC and KKK191-193-AAA-APC were determined and compared to the activities of recombinant wild type (rwt)-APC and of a hydrolytically inactive mutant, S360A-APC, containing Ala in place of the active site residue, Ser360. The two APC protease domain loop variants, RR229/230AA-APC and KKK191-193-AAA-APC, had the same enzymatic activity against a small chromogenic substrate, S-2366, as recombinant wild-type APC (rwt-APC) (FIG. 3a), indicating the structural and functional preservation of the APC active site, whereas these variants had markedly decreased anticoagulant activity (FIG. 3b) that was due to impaired cleavage at Arg506 in factor Va (see Table 2). TABLE 2 Recombinant wild type and mutant APC activities.* (anticoagulant activity determined by APTT) factor Va PAR-1 cytoprotective inactivation peptide cytoprotective anticoagulant to cleavage at amidolytic (TR33-62) APC sequence activity activity anticoagulant Arg506 (Arg306) activity cleavage Mutant (mutated to Ala) (% rwt-APC)† (% rwt-APC)‡ ratio$ (% rwt-APC) (% rwt-APC)¶ (% rwt-APC)# rwt-APC* none 100% 100% 1.0 100% (100%) 100% 100% 229/230-APC 227-DLRRWE-232 94% 13% 7.2 25% (110%) 102% 116% 3K3A-APC 189-DSKKKLA-195 114% 4.6% 25 11% (67%) 109% 88% S360A-APC 358-GDSGG-362 <1%** 23%†† 0 <1%** (<1%**) <1%** <3%** *Recombinant wild-type APC (rwt-APC) activity was defined as 100% and values for mutant APC's are given as percentage of rwt-APC activity. †Derived from the concentrations of APC required for half-maximal inhibition of the staurosporine-induced apoptosis (FIG. 2a). ‡Based on the APTT dose-response data determined for rwt-APC and APC variants (0.5 nM-32 nM) (FIG. 1b). $Derived from the ratio of relative activities for cytoprotective and anticoagulant activities given in the previous two columns of this Table. Based on apparent second-order rate constants determined previously (Gale et al., supra, 2002; Gale et al., supra, 1997). ¶Based on the amidolytic activity determined for rwt-APC and APC variants (0.5 nM-32 nM) (FIG. 1a). 190 Based on the catalytic efficiency derived from FIG. 4 for cleavage of the PAR-1 peptide (TR33-62) by rwt-APC and APC variants (500 nM). **No detectable activity under the conditions of the assay. ††Anticoagulant activity of S360A-APC is not due to proteolysis of factor Va and in contrast to rwt-APC is independent of the incubation time of APC with the plasma (Gale et al., supra, 1997). Although S360A-APC had no chromogenic activity (FIG. 3a), the anticoagulant activity of S360A-APC was ˜23% in the conditions of the APTT assay (FIG. 3b). As previously described, in contrast to normal rwt-APC, this anticoagulant activity is independent of the incubation time of APC with plasma (Gale et al., supra, 1997) and appears to involve binding of APC exosites to factor Va such that there is inhibition of factor Xa and prothrombin binding to factor Va. To determine cytoprotective activity of these APC variants, staurosporine-induced endothelial cell apoptosis (Joyce et al., supra, 2001; Mosnier and Griffin, supra, 2003) was studied. APC-mediated inhibition of staurosporine-induced apoptosis is time-dependent and dose-dependent and it requires APC's active site, PAR-1 and EPCR (Mosnier and Griffin, supra, 2003). Half-maximum inhibition of staurosporine-induced apoptosis by rwt-APC was achieved at 0.16 nM under the conditions employed (FIG. 4a). Dose-dependent inhibition of apoptosis by RR229/230AA-APC and KKK191-193AAA-APC was indistinguishable from that of rwt-APC with half-maximum inhibition at 0.17 nM and 0.14 nM, respectively (FIG. 4a). No inhibition of apoptosis by an APC mutant lacking the active site serine, S360A-APC (Gale et al., supra, 1997), was observed (FIG. 4a-c). The ability of rwt-APC and APC variants to inhibit generation of activated caspase 3 in endothelial cells exposed to staurosporine was monitored immunohistochemically. rwt-APC and the variants, RR229/230AA-APC and KKK191-193AAA-APC, each similarly reduced activated caspase-3-positive cells by approximately 70%, whereas the active site mutant, S360A-APC, had no effect (FIG. 4b-c). Thus, certain protease domain residues essential for normal anticoagulant activity of APC, namely Arg229 and Arg230 and Lys191, Lys192 and Lys193, are not required for normal anti-apoptotic activity of APC. APC anti-apoptotic effects require PAR-1 and EPCR (Cheng et al., supra, 2003; Mosnier and Griffin, supra, 2003). Similarly, the anti-apoptotic activity of RR229/230AA-APC and KKK191-193AAA-APC in assays of staurosporine-induced endothelial cell apoptosis required PAR-1 and EPCR because the cytoprotective activity of each APC variant was inhibited by 72% and 69% in the presence of antibodies against EPCR that block binding of APC to the receptor and by 88% and 55% in the presence of blocking anti-PAR-1 antibodies, respectively (FIG. 5). These results indicate that interactions between cells and the two APC variants, like rwt-APC, require PAR-1 and EPCR. Cleavage of Synthetic PAR-1 N-terminal Tail by Wild Type and Variant APC's The absence of anti-apoptotic activity of S360A-APC and the requirement for PAR-1 imply that a primary mechanistic step for APC's anti-apoptotic activity involves PAR-1 proteolytic activation (Cheng et al., supra, 2003; Mosnier and Griffin, supra, 2003). To characterize the effects of the mutations in APC on proteolytic activation of PAR-1 due to cleavage at Arg41, a synthetic 30-mer peptide representing the PAR-1 N-terminal sequence (residues 33-62 (TR33-62)) was studied as an APC substrate. This TR33-62 PAR-1 peptide is cleaved at Arg41 by thrombin (Arosio et al., supra, 2000). APC cleaves another PAR-1 synthetic N-terminal peptide at Arg41, the thrombin cleavage site (Kuliopulos et al., supra, 1999). Using HPLC quantitative analysis, we found that rwt-APC cleaved the TR33-62 peptide at Arg41 and generated similar fragments as thrombin, TR33-41 and TR42-62, but at approximately a 25,000-fold lower catalytic efficiency based on comparison of kcat/Km for the two enzymes (data not shown). When the time course for TR33-62 cleavage was monitored using HPLC to quantify the disappearance of the peak for the TR33-62 substrate and the appearance of the TR42-62 product, the results showed that there were no substantial differences in the rate of TR33-62 cleavage between the rwt-APC, RR229/230AA-APC and KKK191-193AAA-APC (FIG. 6). Similarly, no significant differences in APC-induced Ca++-intracellular flux monitored as FURA-2-AM fluorescence changes were observed in EA.hy926 endothelial cells when rwt-APC was compared with the two anti-apoptotic APC variants, RR229/230AA-APC and KKK191-193AAA-APC (data not shown). These results are consistent with the hypothesis that APC cleaves PAR-1 at Arg41 and that the mutations in the two APC variants described here with reduced anticoagulant activity but with normal anti-apoptotic activity did not significantly reduce the ability of the protease domain of APC to cleave PAR-1 at Arg41. In summary, to generate recombinant APC variants with reduced risk of bleeding due to reduced anticoagulant activity, we dissected APC's anticoagulant activity from its cytoprotective activity by site-directed mutagenesis. Using staurosporine-induced endothelial cell apoptosis assays, we show here that Ala mutations (RR229/230AA and KKK191-193AAA) in two APC surface loops that severely reduce anticoagulant activity result in two APC variants that retain normal anti-apoptotic activity that requires protease activated receptor-1 and endothelial cell protein C receptor. Moreover, these two APC variants retain a normal ability to cleave a PAR-1 N-terminal peptide at Arg41. To compare these two APC variants to rwt-APC in terms of their relative anti-apoptotic and anticoagulant activities (determined by APTT; note in table 1 anticoagulant activity was determined by dilute PT), we assigned the observed activity of rwt-APC a value of 100% and calculated the percent activity of each APC variant from dose-response data (FIGS. 3 and 4). This normalization inherently yields a “cytoprotective to anticoagulant” ratio for rwt-APC of 1.0 (Table 2). When the ratio of anti-apoptotic activity to anticoagulant activity was calculated for the APC mutants (Table 2), the two APC variants exhibited 7-times and 25-times greater anti-apoptotic activity relative to anticoagulant activity compared to rwt-APC, respectively. These ratios are similar to the values seen in Table 1 calculated using the dilute PT assay for anticoagulant activity. Thus, these data imply that the RR229/230AA and KKK191-193AAA mutations in APC which cause decreased cleavage at Arg506 in factor Va do not impair cleavage at Arg41 in PAR-1. The references and patents cited herein, are hereby incorporated by reference in their entirety. | <SOH> BACKGROUND OF THE INVENTION <EOH>Protein C is a member of the class of vitamin K-dependent serine protease coagulation factors. Protein C was originally identified for its anticoagulant and profibrinolytic activities. Protein C circulating in the blood is an inactive zymogen that requires proteolytic activation to regulate blood coagulation through a complex natural feedback mechanism. Human protein C is primarily made in the liver as a single polypeptide of 461 amino acids. This precursor molecule is then post-translationally modified by (i) cleavage of a 42 amino acid signal sequence, (ii) proteolytic removal from the one-chain zymogen of the lysine residue at position 155 and the arginine residue at position 156 to produce the two-chain form (i.e., light chain of 155 amino acid residues attached by disulfide linkage to the serine protease-containing heavy chain of 262 amino acid residues), (iii) carboxylation of the glutamic acid residues clustered in the first 42 amino acids of the light chain resulting in nine gamma-carboxyglutamic acid (Gla) residues, and (iv) glycosylation at four sites (one in the light chain and three in the heavy chain). The heavy chain contains the serine protease triad of Asp257, His211 and Ser360. Similar to most other zymogens of extracellular proteases and the coagulation factors, protein C has a core structure of the chymotrypsin family, having insertions and an N-terminus extension that enable regulation of the zymogen and the enzyme. Of interest are two domains with amino acid sequences similar to epidermal growth factor (EGF). At least a portion of the nucleotide and amino acid sequences for protein C from human, monkey, mouse, rat, hamster, rabbit, dog, cat, goat, pig, horse, and cow are known, as well as mutations and polymorphisms of human protein C (see GenBank accession P04070). Other variants of human protein C are known which affect different biological activities. Activation of protein C is mediated by thromblin, acting at the site between the arginine residue at position number 15 of the heavy chain and the leucine residue at position 16 (chymotrypsin numbering) (See Kisiel, J. Clin. Invest., 64:761-769, 1976; Marlar et al., Blood, 59:1067-1072, 1982; Fisher et al. Protein Science, 3:588-599, 1994). Other proteins including Factor Xa (Haley et al., J. Biol. Chem., 264:16303-16310, 1989), Russell's viper venom, and trypsin (Esmon et al., J. Biol. Chem., 251:2770-2776, 1976) also have been shown to enzymatically cleave and convert inactive protein C to its activated form. Thrombin binds to thrombomodulin, a membrane-bound thrombin receptor on the luminal surface of endothelial cells, thereby blocking the procoagulant activity of thrombin via its exosite I, and enhancing its anticoagulant properties, i.e., activating protein C. As an anticoagulant, activated protein C (APC), aided by its cofactor protein S, cleaves the activated cofactors factor Va and factor VIIa, which are required in the intrinsic coagulation pathway to sustain thrombin formation (Esmon et al., Biochim. Biophys. Acta., 1477:349-360, 2000a), to yield the inactivated cofactors factor Vi and factor VIIIi. The thrombin/thrombomodulin complex mediated activation of protein C is facilitated when protein C binds to the endothelial protein C receptor (EPCR), which localizes protein C to the endothelial cell membrane surface. When complexed with EPCR, APC's anticoagulant activity is inhibited; APC expresses its anticoagulant activity when it dissociates from EPCR, especially when bound to negatively charged phospholipids on activated platelet or endothelial cell membranes. Components of the protein C pathway contribute not only to anticoagulant activity, but also to anti-inflammatory functions (Griffin et al., Sem. Hematology, 39:197-205, 2002). The anti-inflammatory effects of thrombomodulin, recently attributed to its lectin-like domain, can protect mice against neutrophil-mediated tissue damage (Conway et al., J. Exp. Med. 196:565-577, 2002). The murine centrosomal protein CCD41 or centrocyclin, involved in cell-cycle regulation is identical to murine EPCR lacking the first N-terminal 31 amino acids (Rothbarth et al., FEBS Lett., 458:77-80, 1999; Fukodome and Esmon, J. Biol. Chem., 270:5571-5577,1995). EPCR is structurally homologous to the MHC class 1/CD1 family of proteins, most of which are involved in inflammatory processes. This homology suggests that the function of EPCR may not be limited to its ability to localize APC or protein C on the endothelial membrane (Oganesyan et al., J. Biol. Chem., 277:24851-24854, 2002). APC provides EPCR-dependent protection against the lethal effects of E.coli infusion in baboons (Taylor et al., Blood, 95:1680-1686, 2000) and can downregulate proinflammatory cytokine production and favorably alter tissue factor expression or blood pressure in various models (Shu et al., FEBS Lett. 477:208-212, 2000; Isobe et al., Circulation, 104:1171-1175, 2001; Esmon, Ann. Med., 34:598-605, 2002). Inflammation is the body's reaction to injury and infection. Three major events are involved in inflammation: (1) increased blood supply to the injured or infected area; (2) increased capillary permeability enabled by retraction of endothelial cells; and (3) migration of leukocytes out of the capillaries and into the surrounding tissue (hereinafter referred to as cellular infiltration) (Roitt et al., Immunology, Grower Medical Publishing, New York, 1989). Many serious clinical conditions involve underlying inflammatory processes in humans. For example, multiple sclerosis (MS) is an inflammatory disease of the central nervous system. In MS, circulating leukocytes infiltrate inflamed brain endothelium and damage myelin, with resultant impaired nerve conduction and paralysis (Yednock et al., Nature 366:63-66 (1992)). Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of tissue damage caused by self antigen directed antibodies. Auto-antibodies bound to antigens in various organs lead to complement-mediated and inflammatory cell mediated tissue damage (Theofilopoulos, A.N., Encyclopedia of Immunology, pp. 1414-1417 (1992)). APC has not only anticoagulant and anti-inflammatory activities but also anti-apoptotic activity. EPCR has been found to be a required cofactor for the anti-apoptotic activity of APC in certain cells, as APC activation of protease activated receptor-1 (PAR-1) is EPCR-dependent (Riewald et al., Science, 2296:1880-1882, 2002; Cheng et al., Nat. Med., 9:338-342, 2003; Mosnier and Griffin, Biochem. J., 373:65-70, 2003). APC also has been shown potentially to inhibit staurosporine-induced apoptosis in endothelial cells in vitro by modulating the expression of NFκB subunits (Joyce et al., J. Biol. Chem., 276:11199-11203, 2001). Staurosporine-induced apoptosis in human umbilical vein endothelial cells (HUVEC) and tumor necrosis factor-α-mediated injury of HUVEC, based on transcriptional profiling, suggest that APC's inhibition of NFκB signaling causes down regulation of adhesion molecules (Joyce et al., supra, 2001). APC's induction of anti-apoptotic genes (e.g., Bcl2-related protein A1 or Bcl2A1, inhibitor of apoptosis 1 or clAP1, endothelial nitric oxide synthase or eNOS) has been interpreted as a possible mechanism linked to APC's anti-apoptotic effects in a staurosporine model of apoptosis. APC has a remarkable ability to reduce all-cause 28-day mortality by 19% in patients with severe sepsis (Bernard et al., New Engl. J. Med. 344:699-709, 2001a), whereas, potent anticoagulant agents such as antithrombin III and recombinant TFPI have failed in similar phase III clinical trials (Warren et al., JAMA, 286:1869-1878, 2001; Abraham et al., Crit. Care Med., 29:2081-2089). The explanation for this difference may lie in the recently described anti-apoptotic activity of APC, as well as its anti-inflammatory activity. The clinical success of APC in treating sepsis may be related to its direct cellular effects that mediate its anti-apoptotic or anti-inflammatory activity. In spite of the numerous in vivo studies documenting the beneficial effects of APC, there is limited information about the molecular mechanisms responsible for APC's direct anti-inflammatory and anti-apoptotic effects on cells. APC can directly modulate gene expression in human umbilical vein endothelial cells (HUVEC) with notable effects on anti-inflammatory and cell survival genes (Joyce et al., supra, 2001; Riewald et al., supra, 2002). Riewald et al. have shown this direct effect of APC on certain cells requires PAR-1 and EPCR (Riewald et al., supra, 2002), although they provided no data that related APC functional activity with PAR-1-signaling. Recombinant activated protein C (rAPC), similar to Xigris (Eli Lilly & Co.), is approved for treating severe sepsis and it may eventually have other beneficial applications. However, clinical studies have shown APC treatment to be associated with increased risk of serious bleeding. This increased risk of bleeding presents a major limitation of APC therapy. If APC's effects in sepsis can be attributed to its anti-inflammatory and cell survival activities, a compound that retains the beneficial anti-apoptotic or cytoprotective activity but has a less anticoagulant activity is desirable. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of this invention to provide variants (mutants) of recombinant APC and prodrugs (e.g., variants of recombinant protein C) as therapeutics or research tools for use in alleviating or preventing cell damage associated at least in part with apoptosis. It is also an object of this invention to provide a method of alleviating or preventing cell damage associated at least in part with apoptosis, especially in subjects at risk for or suffering from such cell damage. Another object of this invention is to provide a means for screening candidate mutants for use in accordance with the invention. The invention is directed to variants of recombinant APC and prodrugs (protein C variants) that provide reduced anticoagulant activity relative to anti-apoptotic activity compared to wild-type, and, therefore, have use as cytoprotective agents. Two examples of such recombinant APC mutants are KKK191-193AAA-APC (mutation of lysines 191, 192 and 193 to alanines) and RR229/230AA-APC (mutation of arginines 229 and 230 to alanines). As we demonstrate herein, these exemplary APC variants retain the desirable property of normal anti-apoptotic, cytoprotective activity but provide significantly reduced risk of bleeding, given their reduced anticoagulant activity. The APC and protein C variants of the invention provide a ratio of anti-apoptotic to anticoagulant activity greater than that of wild-type APC (i.e., >1.0). In one embodiment of the invention, a method of preventing or alleviating damage associated at least in part with apoptosis is provided. In a related aspect of this embodiment, a method of treating subjects at risk for cell damage associated at least in part with apoptosis is provided. These subjects include patients at risk of damage to blood vessels or tissue in various organs caused, at least in part, by apoptosis. At risk patients include, for example, those suffering (severe) sepsis, ischemia/reperfusion injury, ischemic stroke, acute myocardial infarction, acute or chronic neurodegenerative diseases, or those undergoing organ transplantation or chemotherapy, among other conditions. The APC variants and prodrugs of the invention should be useful in treating subjects who will benefit from APC protective activities that are independent of APC's anticoagulant activity. Prodrug embodiments of this invention may involve recombinant protein C variants that, following conversion of protein C to APC, exhibit reduced anticoagulant activity while retaining normal or near-normal cell protective activities. For example, variants of protein C, when activated, will have the desired ratio of anti-apoptotic to anticoagulant activity of greater than 1.0. In another embodiment of the invention, the APC mutants may be provided as therapeutics or in therapeutic compositions, to offer beneficial cytoprotective effects in cells, while carrying much less risk of bleeding. In yet another embodiment of the invention, methods of screening candidate recombinant APC variants having reduced anticoagulant activity, but retaining the beneficial cell protective and anti-inflammatory activities are provided. Given the risk of bleeding associated with wild type activated protein C, the APC mutants of this invention offer advantages over currently available wild-type recombinant APC. Therefore, APC mutants of the invention are expected to provide superior therapy, either alone or adjunctive to other agents, whenever APC might be used for its anti-inflammatory or anti-apoptotic (cell survival) activities, rather than purely for its anticoagulant activity. | 20040708 | 20090303 | 20050217 | 91026.0 | 0 | KOSSON, ROSANNE | ACTIVATED PROTEIN C VARIANTS WITH NORMAL CYTOPROTECTIVE ACTIVITY BUT REDUCED ANTICOAGULANT ACTIVITY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,886,836 | ACCEPTED | Method and system for a mass flow controller with reduced pressure sensitivity | Systems and methods for mass flow controllers which minimize false flow conditions and display a reduced sensitivity to pressure transients are disclosed. Pressure gradients that exist within the volume of a mass flow controller fluid path are minimized in order to limit the potential energy contained in compressed or pressurized process gas. Additionally, process gas pressure may be monitored using a pressure sensor. This pressure signal is utilized in conjunction with a control algorithm to cancel the detrimental effect of certain flow components. These mass flow controllers may be used as drop in replacements for legacy mass flow controllers and reduce the cost of gas sticks due to elimination of discrete components such as pressure regulators, gas filters, pressure transducers, local pressure displays, isolation valves, seals, etc. | 1. A method of reducing the sensitivity of a flow controller to pressure, comprising: sensing a set of conditions; calculating a flow in the flow controller based on one or more of the set of conditions; calculating an error term based on the flow, a setpoint and one or more of the set of conditions; and adjusting the flow controller based on the error term. 2. The method of claim 1, wherein one of the set of conditions is pressure, and the error term is calculated based on the pressure. 3. The method of claim 2, wherein the flow controller is a mass flow controller. 4. The method of claim 3, wherein the pressure is sensed by a pressure sensor located upstream of a flow sensor. 5. The method of claim 4, wherein the error term is calculated based on a scaled derivative of the pressure. 6. The method of claim 5, wherein the scaling of the scaled derivative is determined during calibration or recalibration of the mass flow controller. 7. The method of claim 4, wherein the mass flow controller is adjusted using a control valve. 8. The method of claim 7, wherein the error term is used to generate a drive signal for the control valve. 9. A control system for reducing the sensitivity of a flow controller to pressure, comprising a machine readable medium containing instructions operable to: receive a set of conditions; calculate a flow in the flow controller based on one or more of the set of conditions; calculate an error term based on the flow, a setpoint and one or more of the set of conditions; and adjust the flow controller based on the error term. 10. The control system of claim 9, wherein one of the set of conditions is pressure, and the error term is calculated based on the pressure. 11. The method of claim 10, wherein the flow controller is a mass flow controller. 12. The control system of claim 11, wherein the pressure is sensed by a pressure sensor located upstream of a flow sensor. 13. The control system of claim 12, wherein the error term is calculated based on a scaled derivative of the pressure. 14. The control system of claim 13, wherein the scaling of the scaled derivative is determined during calibration or recalibration of the mass flow controller. 15. The control system of claim 12, wherein the mass flow controller is adjusted using a control valve. 16. The control system of claim 15, wherein the error term is used to generate a drive signal for the control valve. 17. A method for reducing the sensitivity of a flow controller to pressure, comprising: optimizing a flow path of the flow controller. 18. The method of claim 17, wherein a volume of the flow path downstream of a flow sensor and upstream of a control valve is optimized. 19. The method of claim 18, wherein a control valve of the flow controller is positioned vertically. 20. The method of claim 19, wherein the optimization minimizes the volume. 21. The method of claim 20, further comprising sensing the pressure with a pressure sensor. 22. The method of claim 21, wherein the pressure sensor is coupled to the flow path downstream of an inlet and upstream of the flow sensor. 23. The method of claim 22, further comprising receiving a set of conditions; calculating a flow in the flow controller based on one or more of the set of conditions; calculating an error term based on the flow, a setpoint and one or more of the set of conditions; and adjusting the flow controller based on the error term. 24. The system of claim 23, wherein the set of conditions includes the pressure from the pressure sensor and the error term is calculated based on the pressure. 25. A flow controller with reduced sensitivity to pressure, comprising: an inlet; an outlet; a flow path coupled to the inlet and the outlet; a flow sensor coupled to the flow path; a control valve downstream of the flow sensor and upstream of the outlet; wherein a volume of the flow path downstream of the flow sensor and upstream of the control valve is optimized. 26. The system of claim 25, wherein the control valve is positioned vertically. 27. The system of claim 26, wherein the optimization minimizes the volume. 28. The system of claim 26, further comprising a pressure sensor. 29. The system of claim 28, wherein the pressure sensor is coupled to the flow path downstream of the inlet and upstream of the flow sensor. 30. The system of claim 29, wherein the pressure sensor is operable to sense the pressure downstream of the inlet and upstream of the flow sensor. 31. The system of claim 30, further comprising a control system operable to: receive a set of conditions; calculate a mass flow in the flow controller based on one or more of the set of conditions; calculate an error term based on the mass flow, a setpoint and one or more of the set of conditions; and adjust the flow controller based on the error term. 32. The system of claim 31, wherein the set of conditions includes a flow from the flow sensor and a pressure from the pressure sensor and the error term is calculated based on the pressure. 33. The system of claim 32, wherein the error term is calculated based on a scaled derivative of the pressure. 34. The system of claim 33, wherein the error term is used to generate a drive signal for the control valve. 35. A system for reducing the sensitivity of a flow controller to pressure, comprising: a pressure sensor; and a flow controller, including an inlet; an outlet; a flow path coupled to the inlet and the outlet; a flow sensor coupled to the flow path; a control valve downstream of the flow sensor and upstream of the outlet. 36. The system of claim 35, wherein the pressure sensor is coupled to the flow path downstream of the inlet and upstream of the flow sensor. 37. The system of claim 36, wherein the pressure sensor is operable to sense the pressure downstream of the inlet and upstream of the flow sensor. 38. The system of claim 37, further comprising a control system operable to: receive a set of conditions; calculate a mass flow in the flow controller based on one or more of the set of conditions; calculate an error term based on the mass flow, a setpoint and one or more of the set of conditions; and adjust the flow controller based on the error term. 39. The system of claim 38, wherein the set of conditions includes a flow from the flow sensor and a pressure from the pressure sensor and the error term is calculated based on the pressure. 40. The system of claim 39, wherein the error term is calculated based on a scaled derivative of the pressure. 41. The method of claim 40, wherein the error term is used to generate a drive signal for the control valve. 42. The system of claim 39, wherein a volume of the flow path downstream of the flow sensor and upstream of the control valve is optimized. 43. The system of claim 42, wherein the control valve is positioned vertically. 44. The system of claim 43, wherein the optimization minimizes the volume. 45. A gas stick with reduced sensitivity to pressure disturbances, comprising: a pressure sensor coupled to the gas stick; and a flow controller coupled to the gas stick, including an inlet coupled to the gas stick; an outlet coupled to the gas stick; a flow path coupled to the inlet and the outlet; a flow sensor coupled to the flow path; a control valve downstream of the flow sensor and upstream of the outlet. 46. The gas stick of claim 45, wherein the pressure sensor is operable to sense the pressure downstream of the inlet and upstream of the flow sensor. 47. The gas stick of claim 46, wherein the pressure sensor is coupled to the flow path downstream of the inlet and upstream of the flow sensor. 48. The gas stick of claim 47, wherein the flow controller is coupled to a control system operable to: receive a set of conditions; calculate a mass flow in the flow controller based on one or more of the set of conditions; calculate an error term based on the mass flow, a setpoint and one or more of the set of conditions; and adjust the flow controller based on the error term. 49. The gas stick of claim 38, wherein the set of conditions includes a flow from the flow sensor and a pressure from the pressure sensor and the error term is calculated based on the pressure. 50. The gas stick of claim 49, wherein the error term is calculated based on a scaled derivative of the pressure. 51. The gas stick of claim 50, wherein the error term is used to generate a drive signal for the control valve. 52. The gas stick of claim 51, wherein a volume of the flow path downstream of the flow sensor and upstream of the control valve is optimized. 53. The gas stick of claim 46, further comprising a pneumatic shut off valve; and a manual shut off valve. | RELATED APPLICATIONS AND PATENTS This application is related to U.S. Pat. No. 6,343,617, entitled “System and Method of Operation of a Digital Mass Flow Controller,” by Tinsley et al., issued on Feb. 5, 2002; U.S. Pat. No. 6,640,822, entitled “System and Method of Operation of a Digital Mass Flow Controller,” by Tinsley et al., issued on Nov. 4, 2003; U.S. Pat. No. 6,681,787, entitled “System and Method of Operation of a Digital Mass Flow Controller,” by Tinsley et al., issued on Jan. 27, 2004; U.S. Pat. No. 6,389,364, entitled “System and Method for a Digital Mass Flow Controller,” by Vyers, issued on May 14, 2002; U.S. Pat. No. 6,714,878, entitled “System and Method for a Digital Mass Flow Controller,” by Vyers, issued on Mar. 30, 2004; U.S. Pat. No. 6,445,980, entitled “System and Method for a Variable Gain Proportional-Integral (PI) Controller,” by Vyers, issued on Sep. 3, 2002; U.S. Pat. No. 6,449,571, entitled “System and Method for Sensor Response Linearization,” by Tariq et al., issued on Sep. 10, 2002; U.S. Pat. No. 6,575,027, entitled “Mass Flow Sensor Interface Circuit,” by Larsen et al., issued on Jun. 10, 2003; U.S. Pat. No. 5,901,741, entitled “Flow Controller, Parts of Flow Controller, and Related Method,” by Mudd et al., issued on May 11, 1999; U.S. Pat. No. 5,850,850, entitled “Flow Controller, Parts of Flow Controller, and Related Method,” by Mudd, issued on Dec. 22, 1998; U.S. Pat. No. 5,765,283, entitled “Method of Making a Flow Controller,” by Mudd, issued on Jun. 16, 1998. All patents and applications cited within this paragraph are fully incorporated herein by reference. TECHNICAL FIELD OF THE INVENTION The invention relates in general to methods and systems for operating a mass flow controller with a closed loop control system, and more particularly, to a mass flow controller with reduced sensitivity to pressure fluctuations in the flow stream. BACKGROUND OF THE INVENTION Modern manufacturing processes sometimes require precise stoichiometric ratio of chemical elements during particular manufacturing phases. To achieve these precise ratios, different process gases may be delivered into a process chamber during certain manufacturing phases. A gas panel may be used to deliver these process gasses to a process tool with one or more chambers or reactors. A gas panel is an enclosure containing one or more gas pallets dedicated to deliver process gases to the process tool. The gas panel is in turn composed of a group of gas pallets, which is itself composed of a group of gas sticks. A gas stick assembly may contain several discrete components such as an inlet fitting, manual isolation valve, binary controlled pneumatic isolation valves, gas filters, pressure regulators, pressure transducers, inline pressure displays, mass flow controllers and an outlet fitting. Each of these components is serially coupled to a common flow path or dedicated channel for one particular process gas. A manifold and a valve matrix channel the outlet of each gas stick to the process chamber. To achieve a certain stoichiometric ratio a process tool controller asserts setpoints to the mass flow controllers, and sequences the valve matrices, associated with certain gas sticks. The indicated flow value is output by the mass flow controller of each gas stick and monitored by the process tool controller. A mass flow controller (MFC) is constructed by interfacing a flow sensor and proportioning control valve to a control system. The flow sensor is coupled to the control system by an analog to digital converter. The control valve is driven by a current controlled solenoid valve drive circuit. A mass flow measurement system is located upstream of the control valve. The control system monitors the setpoint input and flow sensor output while refreshing the control valve input and indicated flow output. The closed loop control algorithms executed by the control system operate to regulate the mass flow of process gas sourced at the inlet fitting through the proportioning control valve and outlet fitting such that the real-time difference or error between the setpoint input and indicated flow output approaches zero or null as fast as possible with minimal overshoot and as small a control time as possible. A critically damped response characteristic is desired. Furthermore, the mass flowing into the inlet fitting is desired to be equivalent to the mass flowing from the outlet fitting. The mass flow sensor is coupled to the MFC flow path using a bypass arrangement along a partial restriction in the flow path that ensures laminar flow in the flow measurement portion of the MFC. The thermal sensor samples only a portion of gas that flows from the inlet fitting through the control valve and from the outlet fitting. A calibration and validation process is applied to the completed mass flow controller assembly to correlate the digitized value of sampled gas flow to a primary mass flow standard. The control system may execute these programmable curve fitting algorithms to apply the correlation such that the mass flow of the process gas is accurate and linear. This thermal mass flow sensor is constructed by applying heated coils to a capillary tube. The coil material and method of construction are chosen such that the sensor will function as a resistance temperature device or RTD. In an RTD process sensor, a change in resistance maybe proportional to a change in temperature. The heater coils complete an electronic circuit which is designed to precisely excite or energize the coils as well as detect changes in the resistance of the coils. One embodiment of a thermal mass flow sensor has two coils, upstream and downstream. Mass flow through the capillary tube will transfer heat from the upstream coil to the downstream coil as a function of the heat capacity of the gas species flowing through the capillary tube. The downstream coil resistance will change in proportion to the mass flow of the gas species source connected to the inlet fitting of the mass flow controller. However, MFCs of this type, and their control algorithms, may be particularly sensitive to pressure fluctuation in the process gases and may indicate false flow conditions. Upstream pressure disturbances are caused by the transient stability of discrete pressure regulators located upstream of the MFC inlet fitting or perturbations in the upstream pressure source. False flow conditions occur when a pressure gradient exists within the volume of the MFC fluid path, specifically in the volume that exist downstream of the thermal sensor and upstream of the control valve. Both types of disturbances are a function of the capacity of the gas source, impedance or conductance of the gas delivery system and abrupt transitions in gas flow. Unfortunately, typical techniques for enhancing the bandwidth of the thermal sensor employed by MFCs inject high frequency components into the indicated flow signal that do not reflect the true value of the actual mass flow exiting the outlet fitting of the mass flow controller during upstream pressure disturbances. The magnitude of the temporary error in flow indication is a function of the volume in the flow path that is downstream of the thermal flow sensor and upstream of the control valve associated with the MFC. The compensated thermal sensor output measures mass flow upstream of the control valve. The real-time position of the throttling control valve is computed by the closed loop control algorithm executed by the control system. As the pressure in this volume changes, the compensated output of the thermal sensor changes. The control system reacts to a change in sensed mass flow by throttling the valve to reduce the error between the setpoint value and the indicated flow value to zero. An error term equivalent to zero assumes that the mass flow rate of actual process gas flowing into the inlet fitting is equivalent to actual process gas flowing from the outlet fitting. This temporary perturbation in indicated flow and actual process gas flow can result in poor transient or steady state stability that can cause wafer damage, tool alarms or unscheduled downtime. Thus, there is a need for systems and methods for a mass flow controller which minimize false flow conditions and display a reduced sensitivity to pressure transients. SUMMARY OF THE INVENTION Systems and methods for mass flow controllers which minimize false flow conditions and display a reduced sensitivity to pressure transients are disclosed. These mass flow controllers may be utilized to stabilize the flow of process gases through a gas stick during upstream pressure disturbances as well as provide an indicated flow signal that more accurately reflects the movement of process gas flowing from the outlet fitting of a mass flow controller. Mass flow controllers of this type may also be utilized to reduce the number of components on a typical gas stick. Reduced sensitivity to pressure transients may be achieved by minimizing the pressure gradients that exists within the volume of the mass flow controller fluid path in order to limit the potential energy contained in compressed or pressurized process gas. Additionally, sensitivity of a mass flow controller to pressure transients may be accomplished by monitoring process gas pressure using a pressure sensor. This pressure signal is utilized in conjunction with a control algorithm to reduce the sensitivity of the mass flow controller during pressure disturbances by canceling the detrimental effect of certain flow components. These mass flow controllers may be used as drop in replacements for legacy mass flow controllers and reduce the cost of gas sticks due to elimination of discrete components such as pressure regulators, gas filters, pressure transducers, local pressure displays, isolation valves, seals, etc. In one embodiment, a set of conditions are sensed, a mass flow in the mass flow controller is calculated based on one or more of the set of conditions, an error term based on the mass flow, a setpoint and one or more of the set of conditions is calculated, the mass flow controller can then be adjusted based on the error term. In another embodiment, one of the set of conditions is pressure, and the error term is calculated based on the pressure. In still another embodiment, the pressure is sensed by a pressure sensor located upstream of a mass flow sensor. In yet another embodiment, the error term is calculated based on a scaled derivative of the pressure. In other embodiments, the scaling of the scaled derivative is determined during calibration of the mass flow controller. In some embodiments, the mass flow controller is adjusted using a control valve. In still other embodiments, the error term is used to generate a drive signal for the control valve. In one embodiment a system comprises a mass flow controller, including an inlet, an outlet, a flow path coupled to the inlet and the outlet, a flow sensor coupled to the flow path, a control valve downstream of the flow sensor and upstream of the outlet, wherein a volume of the flow path downstream of the flow sensor and upstream of the control valve is optimized. In similar embodiments, the control valve is positioned vertically and the optimization minimizes the volume. In some embodiments, the system further comprises a pressure sensor coupled to the flow path downstream of the inlet and upstream of the flow sensor operable to sense the pressure downstream of the inlet and upstream of the flow sensor. In another embodiment, the system comprise a control system operable to receive a set of conditions, calculate a mass flow in the mass flow controller based on one or more of the set of conditions, calculate an error term based on the mass flow, a setpoint and one or more of the set of conditions and adjust the mass flow controller based on the error term. In one embodiment, a gas stick comprises a pressure sensor coupled to the gas stick and a mass flow controller coupled to the gas stick, including an inlet coupled to the gas stick, an outlet coupled to the gas stick, a flow path coupled to the inlet and the outlet, a flow sensor coupled to the flow path and a control valve downstream of the flow sensor and upstream of the outlet These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. The following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions or rearrangements. BRIEF DESCRIPTION OF THE DRAWINGS The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer impression of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings, wherein identical reference numerals designate the same components. Note that the features illustrated in the drawings are not necessarily drawn to scale. FIG. 1 represents a persistent upstream perturbation test where inlet pressure is varied utilizing 45 PSIA nominal and 5 PSID peak to peak. FIG. 2 represents an upstream crosstalk disturbance test utilizing 30 PSIA nominal and 2 PSID decay and recovery. FIG. 3 includes an illustration of one embodiment of a mass flow controller design that enables reduced sensitivity to pressure changes. FIG. 4 includes a block diagram of a control system for use with a mass flow controller. FIG. 5 depicts the response of a mass flow controller to a test of the type depicted in FIG. 2. FIG. 6 depicts the response of a mass flow controller to a test of the type depicted in FIG. 1. FIG. 7 includes one embodiment of a gas stick. FIG. 8 includes an illustration of one embodiment of a mass flow controller design that enables reduced sensitivity to pressure changes. FIG. 9 includes a block diagram of a control system for use with a mass flow controller and pressure sensor. FIG. 10 depicts the response of a mass flow controller to a test of the type depicted in FIG. 2 FIG. 11 depicts the response of a mass flow controller to a test of the type depicted in FIG. 1. FIG. 12 depicts the relative performance of two embodiments of a mass flow controller. FIG. 13 includes one embodiment of a gas stick. DESCRIPTION OF PREFERRED EMBODIMENTS The invention and the various features and advantageous details thereof are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known starting materials, processing techniques, components and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only and not by way of limitation. After reading the specification, various substitutions, modifications, additions and rearrangements which do not depart from the scope of the appended claims will become apparent to those skilled in the art from this disclosure. Before describing embodiments of the present invention, two types of pressure disturbance test which may be utilized to measure the efficacy of a mass flow controller's response to these pressure variations in a gas flow are presented. FIG. 1 represents a persistent perturbation test where inlet pressure is varied utilizing 45 PSIA nominal and 5 PSID peak to peak. FIG. 2 represents a crosstalk disturbance test utilizing 30 PSIA nominal and 2 PSID decay and recovery. The response of a mass flow controller and its control system to each of these tests may be observed by measuring the solenoid valve drive signal input to the mass flow controller in response to these pressure disturbances, the actual gas flow measurement from the mass flow controller, the indicated flow signal output by the mass flow controller and the actual pressure at the inlet of the mass flow controller. The tests described with respect to FIG. 1 and FIG. 2 will be utilized in conjunction with embodiments of the present invention to display the efficacy of these embodiments in handling pressure transients in the flow of gas. Attention is now directed to systems and methods for flow controllers which minimize false flow conditions and display a reduced sensitivity to pressure transients. These flow controllers may be utilized to stabilize the flow of process gases through a gas stick during upstream pressure disturbances as well as provide an indicated flow signal that more accurately reflects the movement of process gas flowing from the outlet fitting of a mass flow controller. Flow controllers of this type may also be utilized to reduce the number of components on a typical gas stick. These systems and methods may allow a flow controller to exhibit reduced sensitivity to pressure transients by minimizing the pressure gradients that exists within the volume of the mass flow controller fluid path in order to limit the potential energy contained in compressed or pressurized process gas. These systems and methods may also reduce the sensitivity of a flow controller to pressure transients by monitoring process gas pressure using a pressure sensor. This pressure signal is utilized in conjunction with a control algorithm to reduce the sensitivity of the mass flow controller during pressure disturbances by canceling the detrimental effect of certain flow components. These flow controllers may be used as drop in replacements for legacy flow controllers, reduce the cost of gas sticks due to elimination of discrete components such as pressure regulators, gas filters, pressure sensors (transducers), local pressure displays, isolation valves, seals, etc., and improve the safety and reliability of manufacturing processes while simultaneously reducing the cost and increasing the yield due to a reduction in the discrete components utilized in the process. Turning now to FIG. 3, one embodiment of a flow controller exhibiting reduced sensitivity to pressure changes is depicted. Flow controller 300 may function as a mass flow controller and comprise inlet fitting 310, flow restrictor 320, mass flow sensor 330, control valve 340, solenoid 350, outlet fitting 360 and I/O coupling 370 for communicating with a control system or process management system. Gas enters mass flow controller 300 through inlet fitting 310 flows through flow restrictor 320, control valve 340 and outlet fitting 360. The volume of gas flowing through outlet fitting 360 is controlled by control valve 340, which is in turn controlled by solenoid 350. Solenoid 350 opens and closes control valve 340 based on signals received through I/O coupling 370 to regulate the flow through outlet fitting 360. In one embodiment, solenoid 350 actuates a diaphragm isolated throttling ball-seat valve. Electrical current is applied to solenoid 350 which produces magnetic flux that is coupled to a plunger assembly or armature which displaces the ball from the valve seat. The force generated by the solenoid valve works against the force or resistance inherent in the isolation diaphragm and the auxiliary or preload force. A preload force may be applied axially to the ball to ensure a concentric seal with the valve seat such that the value of valve leak through is within a certain tolerance. Mass flow sensor 330 and solenoid 350 may be coupled to a control system. Flow sensor 330 may be coupled to the control system by utilizing an analog to digital converter. The control system monitors the setpoint input, and output of flow sensor 330, while refreshing the control valve drive signal and indicated flow output. The closed loop control algorithms executed by the control system operate to regulate the mass flow of process gas sourced at inlet fitting 310 through control valve 340 and outlet fitting 360 such that the real-time difference or error between the setpoint input and indicated flow output is zero or null as fast as possible with minimal overshoot and as small a control time as possible. A critically damped response characteristic is desired. Furthermore, the difference between the mass flowing into inlet fitting 310 is desired to be equivalent to the mass flowing from outlet fitting 360. Mass flow sensor 330 is coupled to the flow path of mass flow controller 300 using a bypass arrangement along a partial restriction in the flow path that ensures laminar flow in the flow measurement portion of the mass flow controller 300. The sensor 330 samples only a portion of gas that flows from inlet fitting 310 through control valve 340 and from outlet fitting 360. A calibration and validation process may be applied to the completed mass flow controller assembly 300 to correlate the digitized value of sampled gas flow to a primary mass flow standard. The control system may then execute programmable curve fitting algorithms to apply the correlation such that the mass flow of the process gas is accurate and linear within the published performance claims. In one embodiment, mass flow sensor 330 is a thermal mass flow sensor and is constructed by applying at least two heated coils to a capillary tube. The coil material and method of construction are chosen such that the sensor will function as a resistance temperature device or RTD. In an RTD type of sensor, a change in resistance is proportional to a change in temperature. The heater coils complete an electronic circuit which is designed to precisely excite or energize the coils as well as detect changes in the resistance of the coils. One embodiment of a thermal mass flow sensor has two coils, upstream and downstream. Mass flow through the capillary tube will transfer heat from the upstream coil to the downstream coil as a function of the heat capacity of the gas species flowing through the capillary tube. The downstream coil resistance will change in proportion to the mass flow of the gas species source connected to inlet fitting 310 of mass flow controller 300. In some cases, the uncompensated real-time output of thermal mass flow sensor 330, F(t), may be ill-suited for real-time closed loop control due to its' natural time constant or bandwidth. The time domain transfer function approximation of thermal sensor 330 to a unit step input function, u(t), is F(t)=K*(1−e−t/τ . . . where τ is the 1st order time constant of the exponential based approximation and K is a constant based upon the design and construction of the thermal sensor. This approximation may not include the higher order time constants, non-linearities, fluid transportation lags and the dead-time that exist in the actual embodiment. However, the 1st order model may be sufficient for modeling the behavior of this system. The 1st order time constant of the Tylan small bore thermal sensor may be approximately 1.7 seconds for N2 gas when biased with an excitation current of ˜10.8 mA and a bypass split ratio which produces a full scale sensor flow of ˜2 to 3 sccm. The value of τ varies for different gases and flow rates, as is known in the art. One method of enhancing the bandwidth of the thermal flow sensor is to add a weighted amount of the 1st derivative of the thermal sensor output to the real-time thermal sensor output. The 1st derivative of F(t) is dF(t)/dt=(1/τ . . . *e−t/τ˜. Indicated Flow=F(t)+G*dF(t)/dt, where G=the gain or weight of the derivative of F(t). Setting G=τ may yield an indicated flow value of 1 or unity which matches the input function, u(t). Theoretically, this allows for real-time metering of the actual flow. This scenario is the mathematical basis for enhancing the thermal sensor signal bandwidth to obtain near real-time mass flow metering and feedback to the closed loop control system. The value of τ may be uniquely tuned or chosen for each flow controller to achieve reproducible and uniform transient response performance. The control system uses sampled data and difference equations to numerically construct the derivative function for the purpose of enhancing the natural bandwidth of the thermal sensor. For example, one proven method is to compute the derivative value over a time period of ˜20 mS. This technique provides a sufficient amount of signal to effectively enhance the thermal sensor natural bandwidth. Therefore, dF(t)/dt |t=kT=(nT)−1*[f(kT)−f((k−n)*T)], where k=most recent sample, T=sampling frequency=500 uS, and n=40 to yield a dt=20 mS. Moving briefly to FIG. 4, a block diagram for one embodiment of a control system which may be utilized in conjunction with mass flow controller 300 is depicted. Control system 400 may utilize a closed loop control algorithm which receives input 410 from thermal mass flow sensor 330 corresponding to the perceived mass flow of a gas through the capillary tube to which mass flow sensor 300 is coupled. This signal may then be passed through a low pass filter (LPF) 412 and compared with zero value 414 assigned to the zero or natural offset of thermal mass flow sensor 330. The zero value 414, or natural offset, is the value that thermal sensor 330 outputs after it has been properly warmed-up and during a no mass flow condition. This signal may then be fit to a stored curve by curve fitting algorithm 420 to correlate the value of sampled flow gas to a primary mass flow standard. These correlation curves may be determined in the field during a recalibration process or during a calibration and validation process for mass flow controller 300 during which observed sample gas flow through mass flow controller 300 is correlated with a primary mass flow standard. This correlation may then be applied by curve fitting algorithm 420 to generate an enhance flow rate signal. After the signal is fitted to a curve the resulting enhanced signal may be passed through LPF 422, and combined with one or more scaled derivatives 430 of the enhanced flow rate signal, which may include scaled first or second derivatives of enhanced flow rate signal, to produce flow rate signal 440 that more accurately represents flow rate through mass flow controller 300. This flow rate signal may then be compared to setpoint signal 450 to create an error signal, which may in turn be provided to proportional integral controller 460 to generate solenoid control signal 470 for mass flow controller 300. Returning now to FIG. 3, mass flow controller 300 may receive solenoid drive signal 470 from control system 400. Based on solenoid drive signal 370, solenoid 350 may actuate control valve 340 to increase or reduce the flow of gas through outlet fitting 360 of mass flow controller 300. Occasionally, however, when enhancing the bandwidth of thermal sensor 330 the weighted rate of change component injects high frequency components into the indicated flow signal that do not reflect the true value of the actual mass flow exiting outlet fitting 360 of mass flow controller 300 during upstream pressure disturbances. The magnitude of the temporary error in flow indication may be proportional to the volume in the flow path that is downstream of thermal flow sensor 330 and upstream of control valve 340. The compensated thermal sensor output measures mass flow upstream of control valve 340. The real-time position of control valve 340 is computed by a closed loop control algorithm executed by control system 400. As the pressure in this volume changes, the compensated output of thermal sensor 330 changes. Control system 400 reacts to a change in sensed mass flow by throttling control valve 340 (through solenoid drive signal 470) to reduce the error, (e.g. setpoint value−indicated flow value), to zero. An error term equivalent to zero assumes that the mass flow rate of actual process gas flowing into inlet fitting 310 is equivalent to actual process gas flowing from outlet fitting 360. Consequently, a temporary perturbation in indicated flow or actual process gas flow can result in poor transient or steady state stability that can cause wafer damage, tool alarms or unscheduled downtime. Upstream pressure disturbances may be caused by the transient stability of discrete pressure regulators located upstream of inlet fitting 310 or perturbations in the upstream pressure source. Both these types of disturbances are a function of the capacity of the gas source, impedance or conductance of the gas delivery system and abrupt transitions in gas flow. Additionally, pressure disturbances of a specific bandwidth may change the pneumatic gain of control valve 340 at a rate outside of the natural bandwidth of thermal sensor 330. During upstream pressure disturbance events the estimation or bandwidth enhancement portion of the compensated thermal sensor output value exceeds the actual value of the process gas flow exiting outlet fitting 360 such that mass flow regulation is momentarily destabilized. These false flow conditions may occur when pressure gradients exist within the volume of the fluid path of mass flow controller 300, and are exacerbated when these pressure gradients exist within the internal volume 380 of the fluid path that exists downstream of thermal sensor 330 and upstream of control valve 340. In one embodiment, internal volume 380 of fluid path of mass flow controller 300 is optimized to limit the potential energy contained in compressed or pressurized gas flowing through the fluid path. This optimization may include minimization of internal volume 380 of the fluid path downstream of thermal sensor 330 and upstream of control valve 340. A smaller internal volume 380 may also limit the amount of gas flowing through the fluid path that was not accurately metered or detected by thermal sensor 330 during a pressure disturbance. One method of achieving optimization of this portion of fluid path is vertically orienting control valve 340 and solenoid 350 actuating control valve 340, allowing the further optimization of internal volume 380 without regard for any volume of portion of fluid path occupied by control valve 340, actuating solenoid 350, or any mechanism by which solenoid 350 actuates control valve 340. In some embodiments, optimization of internal volume 380 is achieved by designing the gas wetted flow path such that the volume downstream of thermal sensor 330 and upstream of control valve 340 is reduced versus conventional mass flow controllers. A smaller internal volume 380 reduces the magnitude of potential differences in mass flowing into inlet fitting 310, and exiting outlet fitting 360 of mass flow controller 300. One well known form of the ideal gas law is: P*V=n*R*T or n=(P*V)/(Ro*T), where n=number of moles or a quantity of gas=m/M, where m=mass of gas species and M=molecular weight of gas species P=pressure of gas species V=volume containing the gas species R=specific gas constant T=temperature of gas species Thus, the quantity of gas in a volume is smaller if the volume is smaller, and the quantity of gas in a volume varies with the pressure. Changes in pressure upstream of mass flow controller 300 cause a proportional change in pressure in internal volume 380. The rise or fall of pressure in the internal volume 380 has a time constant which is a function of the upstream pressure, mass flow rate and magnitude of the internal volume 380. The time constant may be given as: τc=V/Q, where V=magnitude of optimized internal volume Q=mass flow rate into or out of internal volume K=constant or function for given application The time constant is smaller as the magnitude of volume 380 is reduced or as the magnitude of the mass flow rate is increased. The magnitude of the rate of change of the pressure in internal volume 380 is a function of the time constant as described above and can be approximated with a first order exponential function: ΔP(t)/Δt=G2*e(−t/τ)c, where G2=f(mass flow rate, upstream pressure, mass of gas species, molecular weight of gas species, gas temperature, internal volume) G2 can be embodied as a constant value across the operating range of mass flow controller 300 or as a function of a setpoint value. G2 can be chosen based upon empirical data in the test setup during calibration of mass flow controller 300. Another advantage of optimizing internal volume 380 may be improving the effective signal to noise ratio of the PI compensation component 901 in the error term of the control system of mass flow controller 300 (discussed below). A smaller time constant due to the small magnitude of optimized internal volume 380 produces a larger rate of pressure change signal for a given upstream pressure change. This feature provides significant advantage and flexibility as the rate of pressure change signal does not have to be delayed nor filtered in a manner that inhibits the ability to choose a suitable value of G2 to desensitize the system to upstream pressure changes. Increased signal to noise ratio of the rate of pressure change signal also enables lower effective values of G2 which does not adversely enhance the noise inherent in a pressure sensor output. FIG. 5 depicts the response of mass flow controller 300 to a test of the type depicted in FIG. 2. Line 510 is inlet pressure measurement, line 520 is an indicated flow signal, line 530 is an actual measurement of gas flow, while line 540 represents the solenoid valve drive signal 470 output from control system 400. As inlet pressure 510 drops actual gas flow 530 momentarily spikes while indicated flow signal 520 drops slightly, the opposite occurs when inlet pressure 510 returns to 30.00 PSIA nominal. FIG. 6 depicts the response of mass flow controller 300 to a test of the type depicted in FIG. 1. As can be seen, as inlet pressure 510 fluctuates, actual gas flow 530 may ping pong, causing perturbations within indicated flow signal 520 and consequently making regulation of actual flow 530 through valve drive signal 540 difficult. FIG. 7 depicts a gas stick utilizing mass flow controller 300. Gas enters through gas inlet 710 flows through manual shut-off valve 712, pneumatic shut off valve 714, pressure regulator 716, pressure transducer 718 (local pressure display 720 may display the pressure measured by pressure transducer 718), gas filter 722, pneumatic shut-off valve 724, mass flow controller 300, pneumatic shut-off valve 726, finally exiting gas outlet 730. Mass flow controller 300 may be coupled to control system through I/O coupling 370 in order to regulate gas flow through gas stick 700. Turning now to FIG. 8, another embodiment of a mass flow controller exhibiting reduced sensitivity to pressure changes is depicted. Mass flow controller 800 comprises inlet fitting 810, flow restrictor 820, mass flow sensor 830, control valve 840, solenoid 850, outlet fitting 860, pressure sensor 890 and I/O coupling 870 for communicating with a control system or process management system. Mass flow sensor 830, control valve 840 and solenoid 850 may function in substantially the same manner as described with respect to mass flow sensor 300 depicted in FIG. 3. Additionally, in one embodiment, internal volume 880 of the flow path is also optimized to reduce pressure gradients as discussed above with respect to mass flow controller 300. Pressure sensor 890 may monitor process gas pressure and report a pressure signal through I/O coupling 870 to a control system. Pressure sensor 890 may be located anywhere upstream of flow restrictor 820 and monitor the pressure of a process gas to produce a pressure signal to a control system. In one embodiment, pressure sensor 890 is coupled to the fluid path of mass flow controller 800 downstream of inlet fitting 810 and upstream of flow restrictor 820. Pressure sensor 890 may monitor the process gas pressure downstream of inlet fitting 810 and upstream of thermal sensor 830. Pressure sensor 890 produces a pressure signal which may be quantized by a standard 16 bit analog to digital converter and reported through I/O coupling 870 to a control system along with the output of thermal mass flow sensor 830. In one specific embodiment, pressure sensor 890 is a SolidSense II pressure sensor with an integrated pressure fitting manufactured by the Mykrolis Corporation. FIG. 9 depicts a block diagram of one embodiment of a control system for use in conjunction with mass flow controller 800 depicted in FIG. 8. Control system 900 may execute a closed loop control algorithm which operates to achieve mass flow control exhibiting reduced sensitivity to upstream pressure disturbances by canceling the detrimental effect of the higher frequency indicated flow components. The effect of these high frequency components adversely impacts the transient response or steady state stability of the mass flow controller. Control system 900 may utilize a closed loop control algorithm which receives input 910 from thermal mass flow sensor 930 corresponding to the perceived mass flow of a gas through the capillary tube to which thermal mass flow sensor 830 is coupled. This signal may then be passed through LPF 912 and summed with and compared with zero value 914 assigned to the zero or natural offset of thermal mass flow sensor 830. The zero value 914, or natural offset, is the value that thermal sensor 830 outputs after it has been properly warmed-up and during a no mass flow condition. This signal may then be fit to a stored curve by a curve fitting algorithm 920 to correlate the value of the sampled flow gas to a primary mass flow standard. These correlation curves may be determined during a recalibration or calibration and validation process for mass flow controller as described above. This correlation may then be applied by curve fitting algorithm 920 to generate an enhance flow rate signal. After the signal is fitted to a curve the resulting enhanced signal may be passed through a LPF 922, and combined with one or more scaled derivatives 930 of the enhanced flow rate signal, which may include scaled first or second derivatives of the enhanced flow rate signal to produce a flow rate signal that more accurately represents flow rate through mass flow controller 800. Additionally, control system 900 may receive a signal 980 corresponding to the upstream pressure of mass flow controller 800 from pressure sensor 890. Control system 900 may then create a term that is proportional to the rate of change of upstream pressure using a scaled derivative 990 of the pressure signal 980 from pressure sensor 890. In one particular embodiment, during the recalibration, manufacture or configuration process of mass flow controller 800 or control system 900 a specific scaling of the dP/dt value is chosen such that it cancels the high frequency components of a compensated thermal sensor output that is due to upstream pressure disturbances and provides for a real-time control valve 840 position that enables the mass flow rate of process gas flowing into inlet fitting 810 to be substantially equivalent to the mass flow of process gas exiting outlet fitting 860. The scaling (G2) of scaled derivative 990 may be a function of gas species, upstream pressure, real-time mass flow rate of gas flowing through or into mass flow controller 800, internal volume in mass flow controller 800 and gas temperature. Additionally, the scaling may contribute a component to the real-time error (setpoint (t)−indicated flow (t)+G2*ΔP(t)/Δt) in mass flow controller 800 that actively and accurately cancels either undesired accumulation or undesired reduction of mass in optimized internal volume 880 due to upstream pressure transients sensed by closely coupled upstream pressure sensor 890. The accumulation or reduction of mass in optimized internal volume 880 is undesired when the mass flow rate entering inlet fitting 810 is not equal to the mass flow rate exiting outlet fitting 360. Scaled derivative 990 of pressure signal 980 may then be compared with setpoint value 950, and indicated flow rate 940 to generate an error signal. In one particular embodiment this error signal may be represented by setpoint value−indicated flow value+G2*dP/dt Value. This error term may then be input to variable gain proportional integral controller 960. The output of proportional integral controller is compared with the current bias of control valve 840 and the result input to a solenoid valve driver circuit to generate a solenoid drive signal 970. Therefore, the position of control valve 840 of mass flow controller may now be function of the setpoint, the compensated thermal mass flow output and upstream pressure transients. It should be noted that in this embodiment of control system 900 for achieving immunity to upstream pressure transients the error term may be identical to the error term of control system 400 depicted in FIG. 4 when the upstream pressure at the inlet of mass flow controller 800 is constant. This characteristic enables mass flow controller 800 to be a drop in replacement to legacy mass flow controllers while providing an incremental improvement in wafer yields and tool uptime. FIGS. 10 and 11 depict the performance of mass flow controller 900 containing pressure sensor 890. FIG. 10 depicts the response of mass flow controller 800 to a test of the type depicted in FIG. 2 depending on the scaling of derivative 990 of pressure signal 980. Line 510 is inlet pressure measurement, line 520 is an indicated flow signal, line 530 represents an actual measurement of gas flow, while line 540 represents the solenoid valve drive signal 970 output from control system 900. When the scaling of derivative 990 is optimized during a calibration process, as shown in FIG. 10A, as inlet pressure 510 drops actual gas flow 530 momentarily rises while indicated flow signal 520 drops slightly. The opposite occurs when inlet pressure 510 returns to 30.00 PSIA nominal. However, as can be seen, actual gas flow 530 remains substantially constant regardless of the fluctuations in the inlet pressure 510 of the gas. If the scaling of derivative 990 is low there may be an initial overshoot of actual gas flow 530 when inlet pressure 510 drops and before inlet pressure 510 settles to a steady state as depicted in FIG. 10B. Conversely, there may be an undershoot when inlet pressure 510 rises and before inlet pressure 510 returns to a steady state. If the weighting of derivative is too high, as depicted in FIG. 10C, just he opposite may occur. An initial undershoot of actual gas flow 530 when inlet pressure 510 drops and before inlet pressure 510 settles to a steady state, and an overshoot when inlet pressure 510 rises and before inlet pressure 510 returns to a steady state. FIG. 11 depicts the response of mass flow controller 800 to a test of the type depicted in FIG. 1, depending on the scaling of derivative 990 of pressure signal 980. When the scaling of derivative 990 is optimized during a calibration process, as shown in FIG. 11A, as inlet pressure fluctuates 510, actual gas flow 530 rises and falls turn. The amplitude of these fluctuations in actual gas flow is relatively slight, however, and the indicated flow signal remains relatively constant, allowing easier regulation of actual gas flow through valve drive signal. In contrast, when scaling of derivative 990 is low or high, as depicted in FIGS. 11B and C respectively, the fluctuations in actual gas flow in response to the perturbations in inlet pressure are much greater. Moving on to FIG. 12, the difference in performance between a mass flow controller which utilizes a pressure sensor to compensate for inlet pressure fluctuations and a mass flow controller which does not utilize a pressure sensor to compensate for these pressure fluctuations is illustrated. FIG. 12A depicts the performance of an embodiment of mass flow controller 300, discussed with respect to FIG. 3, to a test of the type depicted in FIG. 1. FIG. 12B depicts the performance of an embodiment of mass flow controller 800, discussed with respect to FIG. 8, to the same test. FIG. 12C depicts the performance of an embodiment of mass flow controller 300, to a test of the type depicted in FIG. 2. FIG. 12D depicts the performance of an embodiment of mass flow controller 800, to the same test. As can be seen from FIG. 12, mass flow controller 800 compensates significantly for upstream pressure fluctuations reducing the detrimental effects of these fluctuations and improving its transient response and steady state stability. FIG. 13 depicts a gas stick utilizing mass flow controller 800 with reduced sensitivity to pressure fluctuations. Gas enters through gas inlet 1310 flows through manual shut-off valve 1312, mass flow controller 800, pneumatic shut-off valve 1326, finally exiting gas outlet 1330. Mass flow controller 800 is coupled to control system through I/O coupling 870 in order to regulate gas flow through gas stick 1300. Gas stick 1300, utilizing mass flow controller 800 with reduced sensitivity to pressure, does not require dedicated pressure regulators, gas filters, pressure transducers and displays including which in turn decreases the quantity of isolation valves and metal seals required for the manufacture of gas stick 1300. The smaller internal volume of reduced sensitivity mass flow controller 800 also enables more efficient purging of the gas delivery system reducing the cycle time of preventive maintenance intervals. In general utilizing gas sticks employing mass flow controllers with reduced pressure sensitivity significantly improves cost of ownership, reliability, form factor and weight of a gas panel. It will be clear to those of ordinary skill in the art after reading this disclosure that mass flow controllers 300, 800 of the type discussed and associated control systems 400, 900 may be implemented in a wide variety of hardware, software or combination of the two. After reading this disclosure, those of ordinary skill in the art will realize which combinations and types of hardware or software will be best suited to a particular use or implementation of the disclosed systems and methods. Note that not all of the hardware or software described is necessary, that an element may not be required, and that further elements may be utilized in addition to the ones depicted, including additional pieces of hardware or software. Additionally, the order in which each element is described is not necessarily the order in which it is utilized. After reading this specification, a person of ordinary skill in the art will be capable of determining which arrangement of hardware or software will be best suited to a particular implementation. In the foregoing specification, the invention has been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention. Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Modern manufacturing processes sometimes require precise stoichiometric ratio of chemical elements during particular manufacturing phases. To achieve these precise ratios, different process gases may be delivered into a process chamber during certain manufacturing phases. A gas panel may be used to deliver these process gasses to a process tool with one or more chambers or reactors. A gas panel is an enclosure containing one or more gas pallets dedicated to deliver process gases to the process tool. The gas panel is in turn composed of a group of gas pallets, which is itself composed of a group of gas sticks. A gas stick assembly may contain several discrete components such as an inlet fitting, manual isolation valve, binary controlled pneumatic isolation valves, gas filters, pressure regulators, pressure transducers, inline pressure displays, mass flow controllers and an outlet fitting. Each of these components is serially coupled to a common flow path or dedicated channel for one particular process gas. A manifold and a valve matrix channel the outlet of each gas stick to the process chamber. To achieve a certain stoichiometric ratio a process tool controller asserts setpoints to the mass flow controllers, and sequences the valve matrices, associated with certain gas sticks. The indicated flow value is output by the mass flow controller of each gas stick and monitored by the process tool controller. A mass flow controller (MFC) is constructed by interfacing a flow sensor and proportioning control valve to a control system. The flow sensor is coupled to the control system by an analog to digital converter. The control valve is driven by a current controlled solenoid valve drive circuit. A mass flow measurement system is located upstream of the control valve. The control system monitors the setpoint input and flow sensor output while refreshing the control valve input and indicated flow output. The closed loop control algorithms executed by the control system operate to regulate the mass flow of process gas sourced at the inlet fitting through the proportioning control valve and outlet fitting such that the real-time difference or error between the setpoint input and indicated flow output approaches zero or null as fast as possible with minimal overshoot and as small a control time as possible. A critically damped response characteristic is desired. Furthermore, the mass flowing into the inlet fitting is desired to be equivalent to the mass flowing from the outlet fitting. The mass flow sensor is coupled to the MFC flow path using a bypass arrangement along a partial restriction in the flow path that ensures laminar flow in the flow measurement portion of the MFC. The thermal sensor samples only a portion of gas that flows from the inlet fitting through the control valve and from the outlet fitting. A calibration and validation process is applied to the completed mass flow controller assembly to correlate the digitized value of sampled gas flow to a primary mass flow standard. The control system may execute these programmable curve fitting algorithms to apply the correlation such that the mass flow of the process gas is accurate and linear. This thermal mass flow sensor is constructed by applying heated coils to a capillary tube. The coil material and method of construction are chosen such that the sensor will function as a resistance temperature device or RTD. In an RTD process sensor, a change in resistance maybe proportional to a change in temperature. The heater coils complete an electronic circuit which is designed to precisely excite or energize the coils as well as detect changes in the resistance of the coils. One embodiment of a thermal mass flow sensor has two coils, upstream and downstream. Mass flow through the capillary tube will transfer heat from the upstream coil to the downstream coil as a function of the heat capacity of the gas species flowing through the capillary tube. The downstream coil resistance will change in proportion to the mass flow of the gas species source connected to the inlet fitting of the mass flow controller. However, MFCs of this type, and their control algorithms, may be particularly sensitive to pressure fluctuation in the process gases and may indicate false flow conditions. Upstream pressure disturbances are caused by the transient stability of discrete pressure regulators located upstream of the MFC inlet fitting or perturbations in the upstream pressure source. False flow conditions occur when a pressure gradient exists within the volume of the MFC fluid path, specifically in the volume that exist downstream of the thermal sensor and upstream of the control valve. Both types of disturbances are a function of the capacity of the gas source, impedance or conductance of the gas delivery system and abrupt transitions in gas flow. Unfortunately, typical techniques for enhancing the bandwidth of the thermal sensor employed by MFCs inject high frequency components into the indicated flow signal that do not reflect the true value of the actual mass flow exiting the outlet fitting of the mass flow controller during upstream pressure disturbances. The magnitude of the temporary error in flow indication is a function of the volume in the flow path that is downstream of the thermal flow sensor and upstream of the control valve associated with the MFC. The compensated thermal sensor output measures mass flow upstream of the control valve. The real-time position of the throttling control valve is computed by the closed loop control algorithm executed by the control system. As the pressure in this volume changes, the compensated output of the thermal sensor changes. The control system reacts to a change in sensed mass flow by throttling the valve to reduce the error between the setpoint value and the indicated flow value to zero. An error term equivalent to zero assumes that the mass flow rate of actual process gas flowing into the inlet fitting is equivalent to actual process gas flowing from the outlet fitting. This temporary perturbation in indicated flow and actual process gas flow can result in poor transient or steady state stability that can cause wafer damage, tool alarms or unscheduled downtime. Thus, there is a need for systems and methods for a mass flow controller which minimize false flow conditions and display a reduced sensitivity to pressure transients. | <SOH> SUMMARY OF THE INVENTION <EOH>Systems and methods for mass flow controllers which minimize false flow conditions and display a reduced sensitivity to pressure transients are disclosed. These mass flow controllers may be utilized to stabilize the flow of process gases through a gas stick during upstream pressure disturbances as well as provide an indicated flow signal that more accurately reflects the movement of process gas flowing from the outlet fitting of a mass flow controller. Mass flow controllers of this type may also be utilized to reduce the number of components on a typical gas stick. Reduced sensitivity to pressure transients may be achieved by minimizing the pressure gradients that exists within the volume of the mass flow controller fluid path in order to limit the potential energy contained in compressed or pressurized process gas. Additionally, sensitivity of a mass flow controller to pressure transients may be accomplished by monitoring process gas pressure using a pressure sensor. This pressure signal is utilized in conjunction with a control algorithm to reduce the sensitivity of the mass flow controller during pressure disturbances by canceling the detrimental effect of certain flow components. These mass flow controllers may be used as drop in replacements for legacy mass flow controllers and reduce the cost of gas sticks due to elimination of discrete components such as pressure regulators, gas filters, pressure transducers, local pressure displays, isolation valves, seals, etc. In one embodiment, a set of conditions are sensed, a mass flow in the mass flow controller is calculated based on one or more of the set of conditions, an error term based on the mass flow, a setpoint and one or more of the set of conditions is calculated, the mass flow controller can then be adjusted based on the error term. In another embodiment, one of the set of conditions is pressure, and the error term is calculated based on the pressure. In still another embodiment, the pressure is sensed by a pressure sensor located upstream of a mass flow sensor. In yet another embodiment, the error term is calculated based on a scaled derivative of the pressure. In other embodiments, the scaling of the scaled derivative is determined during calibration of the mass flow controller. In some embodiments, the mass flow controller is adjusted using a control valve. In still other embodiments, the error term is used to generate a drive signal for the control valve. In one embodiment a system comprises a mass flow controller, including an inlet, an outlet, a flow path coupled to the inlet and the outlet, a flow sensor coupled to the flow path, a control valve downstream of the flow sensor and upstream of the outlet, wherein a volume of the flow path downstream of the flow sensor and upstream of the control valve is optimized. In similar embodiments, the control valve is positioned vertically and the optimization minimizes the volume. In some embodiments, the system further comprises a pressure sensor coupled to the flow path downstream of the inlet and upstream of the flow sensor operable to sense the pressure downstream of the inlet and upstream of the flow sensor. In another embodiment, the system comprise a control system operable to receive a set of conditions, calculate a mass flow in the mass flow controller based on one or more of the set of conditions, calculate an error term based on the mass flow, a setpoint and one or more of the set of conditions and adjust the mass flow controller based on the error term. In one embodiment, a gas stick comprises a pressure sensor coupled to the gas stick and a mass flow controller coupled to the gas stick, including an inlet coupled to the gas stick, an outlet coupled to the gas stick, a flow path coupled to the inlet and the outlet, a flow sensor coupled to the flow path and a control valve downstream of the flow sensor and upstream of the outlet These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. The following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions or rearrangements. | 20040708 | 20070508 | 20051229 | 65970.0 | 1 | KOSOWSKI, ALEXANDER J | METHOD AND SYSTEM FOR A MASS FLOW CONTROLLER WITH REDUCED PRESSURE SENSITIVITY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,886,880 | ACCEPTED | High performance digital loop diagnostic technology | Methods and associated hub arrangements are described for use in diagnosis and recovery in high performance digital loops such as, for example, those seen in Fibre Channel systems. In one system having a hub configured for interconnection of a plurality of stations as part of a digital system such that digital data flows between the stations based on operational status of the system, an arrangement forms part of the hub which arrangement is connectable at points within the hub and between at least two different pairs of the stations for monitoring certain characteristics of the data in a way which provides for non-invasive identification of one or more conditions related to the operational status of the system. | 1-65. (canceled) 66. In a Fibre Channel system including a plurality of stations interconnected through a hub to form a main loop such that each station, including its connection to the hub, forms a lobe of the main loop and such that digital loop data normally flows between the stations on the main loop, a method of verifying the integrity of a selected one of said lobes using said hub, said method comprising the steps of: a) establishing digital test data designed to illicit a predetermined response if received by the station connected to the selected lobe; b) if said digital loop data is flowing through the selected lobe, isolating the selected lobe from the main loop such that the digital loop data continues to flow on the main loop; c) transmitting the digital test data from the hub such that the digital test data is placed enroute to the station connected to the selected lobe; d) thereafter, in the hub, listening on the selected lobe for said predetermined response from the station on the selected lobe; and e) providing an indication as to the integrity of the selected lobe based upon detection of the predetermined response from the station on the selected lobe. 67. The method according to claim 66 wherein the digital test data illicits the predetermined response of the station in the form of a copy of the digital test data. 68. The method according to claim 66 wherein the station on the selected lobe includes a loop state machine and wherein the digital test data is an ordered set which should illicit a different response from the loop state machine as the predetermined response of the station on the selected lobe such that the integrity of the loop state machine is confirmed. 69. The method according to claim 68 wherein said different response is a particular ordered set. 70-126. (canceled) | BACKGROUND OF THE INVENTION The present invention relates generally to the field of digital loop technology utilizing a hub structure and, more particularly, to the field of diagnosis and recovery using a hub in high performance digital loops such as, for example, those hubs seen in Fibre Channel systems. The value of the digital loop in high performance systems such as Fibre Channel is without question. Moreover, the use of such a loop has proven to be enhanced through the use of a hub which serves as a central connection point for the loop. In such a configuration, the loop is said to be in the form of a “star”. Initial development of hubs saw what may be referred to as an unmanaged or “dumb” hub. As these terms indicate, such hubs served much in the manner of a patch panel, devoid of any monitoring capability as to the data passing through the hub. Still considering the hub technology of the prior art, attention is now directed to FIG. 1 which illustrates a more recent digital system generally indicated by the reference numeral 10. System 10 includes a Fibre Channel hub 12 serving to interconnect a loop 14 including a plurality of stations S1-S4. System 10 further includes a local area network (LAN) 16 having independent connections 17a and 17b with stations S1 and S2, respectively. LAN 16 further includes a station S5 as well as a work station (WS) 18. Unlike the earlier generation of hubs described above, hub 12 includes limited diagnostic capabilities. These capabilities have generally been limited to high level observation of the data traveling around the loop. More specifically, these prior art diagnostic capabilities may indicate that certain packets of data are corrupted in addition to indicating the point of origination of the corrupted data. At first blush, this may seem to be extremely useful information for purposes of diagnosis. One must remember, however, that the corrupted data may have traveled through a substantial number of stations between it's point of origin and it's destination. For example, data originating from S2 and destined for S1 on the loop must intermediately pass through stations S3 and S4. Therefore, it is possible for the data to have been corrupted at any point along this path. An unsuspecting system administrator who immediately assumes that S2 is responsible for the corrupted data can waste enormous effort in attempting to diagnose a problem which may occur anywhere along the loop between S2 and S1. Still referring to FIG. 1, in attempting to perform a detailed diagnosis, a technician may utilize a logic or protocol analyzer 20. S2 and hub 12 are originally connected using cable 22. The analyzer may be connected by disconnecting the original cable 22 at one end and then reconnecting the disconnected end to the analyzer such that original cable 22 is represented as a dashed line indicated by the reference number 22a and an additional cable 24 is used to connect the analyzer with S2. Assuming the problem is not being caused by S2, the technician has little hope of resolving the problem using the analyzer as depicted. Thus, the use of an analyzer in such a scenario is disadvantageous. Moreover, as another disadvantage, it is important to note that the use of the analyzer is intrusive. That is, connection of the analyzer itself modifies the structure of the loop. This fact can cause severe complications in some cases. For example, if the problem is being caused by a loose connector (not shown) at S3, connection of the analyzer may make the problem disappear if the output signal of the analyzer is greater than the output signal of S2 whereby to overcome attenuation being caused by the loose connector at S3. In this scenario, a reasonable technician may assume that the problem has somehow corrected itself, since the analyzer will indicate that there are no errors. Unfortunately, however, as soon as the original connections are restored, the masked problem will return. The technician is then likely to remain suspicious of S2, replacing it and its associated connections and is also likely to suspect fiber 22. As can be appreciated, this disadvantageous hit or miss technique is likely to be a long process. Moreover, each time a connection is disturbed to insert the analyzer, the loop is taken out of service. The process can also be expensive just due to replacement of any number of perfectly good, but suspect components. Continuing to consider the use of an analyzer, it should also be appreciated that analyzer diagnosis is further complicated by the fact that the analyzer is generally configured to monitor only one or two points. This is an important consideration since the loop, unlike LAN 16, is not a broadcast medium. That is, the data present between different pairs of stations on loop 14 is itself different since the stations themselves insert and remove data from the loop. Just through the use of an analyzer, it is very difficult to gain a complete “picture” of what is going on in the loop which may, in fact, represent the only way in which a particular problem may be understood. Not only is the analyzer ineffective in many cases, it is also typically expensive. It is not uncommon for a Fibre Channel analyzer to cost $45,000. The present invention provides a highly advantageous arrangement and associated method which resolves the foregoing disadvantages and difficulties while providing still further advantages, as will be seen hereinafter. SUMMARY OF THE INVENTION As will be described in more detail hereinafter, there are disclosed herein methods and associated hub arrangements for use in diagnosis and recovery in high performance digital loops such as, for example, those seen in Fibre Channel systems. Accordingly, within a hub configured for interconnection of a plurality of stations as part of a digital system such that digital data flows between the stations based on operational status of the system, an arrangement forms part of the hub which arrangement is connectable at points within the hub and between at least two different pairs of the stations for monitoring certain characteristics of the data in a way which provides for non-invasive identification of one or more conditions related to the operational status of the system. In one aspect of the invention, recovery from a condition which is adverse to the operation of the system is initiated based on identification of the adverse condition. BRIEF DESCRIPTION OF THE DRAWINGS The present invention may be understood by reference to the following detailed description taken in conjunction with the drawings briefly described below. FIG. 1 is a block diagram illustrating a digital system including a prior art Fibre Channel hub and a prior art analyzer used with the hub. FIG. 2 is a diagrammatic block diagram of a digital system in the form of a loop which is defined using a hub manufactured in accordance with the present invention in an implementation which utilizes a fixed diagnostic unit and a roving diagnostic unit. FIG. 3 is a block diagram illustrating the system of FIG. 2 shown here to illustrate further details of construction of the hub in accordance with the present invention. FIG. 4 is a schematic in block diagram form shown here to illustrate one implementation of an integrated port control circuit manufactured in accordance with the present invention and used in the system shown in FIGS. 2 and 3. FIG. 5 is a partial cut-away view of the system of FIG. 3 in block diagram form shown here to illustrate monitoring in accordance with the present invention using the roving diagnostics unit. FIG. 6 is another partial cut-away view of the system of FIG. 3 in block diagram form shown here to illustrate other aspects of monitoring in accordance with the present invention using the roving diagnostics unit. FIG. 7 is still another partial cut-away view of the system of FIG. 3 in block diagram form shown here to illustrate an initialization procedure performed in accordance with the present invention. FIG. 8 is a partial cut-away view in block diagram form of the system shown in FIG. 3 shown here for purposes of illustrating another initialization procedure performed in accordance with the present invention. FIG. 9 is a diagrammatic illustration of the possible physical appearance of a port connection panel of a hub manufactured in accordance with the present invention shown here to illustrate features incorporated into the hub. FIG. 10 is a diagrammatic illustration of a display screen showing a site management view in accordance with the present invention. FIG. 11 is a diagrammatic illustration of display screen showing a stack view in accordance with the present invention which is obtained by selection in the site management view of FIG. 10. FIG. 12 is a diagrammatic illustration of display screen showing a hub view associated with one of the hubs shown in FIG. 10. FIG. 13 is a diagrammatic illustration of display screen showing a port detail screen that appears through selection of one of the ports in FIG. 12 and which provides information and control facilities for the selected port. FIG. 14 is a diagrammatic illustration of display screen showing a hub sweep view in accordance with the present invention that appears through selection of a logo in FIG. 12 and which provides detailed information for each port in a single view. FIG. 15 is a diagrammatic illustration of display screen showing a per port diagnostic screen in accordance with the present invention. FIG. 16 is a partial cut-away view in block diagram form of the system shown in FIG. 3 shown here for purposes of illustrating full path end-to-end verification performed in accordance with the present invention on a lobe attached to the hub. FIG. 17 is a diagrammatic illustration in block diagram form of a Fibre Channel system including a hub manufactured in accordance with the present invention for use in describing a number of highly advantageous features of the present invention including features relating to diagnostics for evaluation of remote, unmanaged devices. FIG. 18 is a diagrammatic illustration of a data management arrangement implemented on a host system including a method used in the host system for collecting data, evaluating the data and providing indications based thereon in accordance with the present invention. FIG. 19 is a diagrammatic illustration in block diagram form of a Fibre Channel system including two hubs manufactured in accordance with the present invention for use in describing topology mapping performed in accordance with the present invention. FIG. 20 is a diagrammatic illustration in block diagram form of a Fibre Channel system including two hubs at least one of which is manufactured in accordance with the present invention for use in describing hot cascading performed in accordance with the present invention. FIG. 21 is a flow diagram illustrating a first hot cascading method performed in accordance with the present invention on the system of FIG. 20. FIG. 22 is a flow diagram illustrating a second hot cascading method performed in accordance with the present invention on the system of FIG. 20. FIG. 23 is a diagrammatic illustration of an integrated port control circuit manufactured in accordance with the present invention shown here to illustrate the pin out of the integrated circuit. FIG. 24 is a diagram illustrating the hierarchical presentation of display views used by the present invention. FIG. 25 is a display view showing a Loop View having a tree type structure. FIG. 26 illustrates a display similar to the display depicted by FIG. 12, however, a Hub View corresponding to Stack 2, Hub 1 is shown. FIG. 27 illustrates a display similar to the display depicted by FIG. 12, however, a Hub View corresponding to Stack 2, Hub 3 is shown. FIG. 28 illustrates the display of a management view. FIG. 29 illustrates the display of a hardware debug view for use in system diagnosis in accordance with the present invention shown here to illustrate the appearance of a “Ports” tab screen. FIG. 30 illustrates the display of the hardware debug view of FIG. 29, however, a “Hub” tab has been selected illustrating the appearance of the Hub tab screen. FIG. 31 illustrates the display of the hardware debug view of FIG. 29, however, a “Loop” tab has been selected illustrating the appearance of the Loop tab screen. FIG. 32 illustrates the display of the hardware debug view of FIG. 29, however, a “Stack” tab has been selected illustrating the appearance of the Stack tab screen. FIG. 33 illustrates the display of the hardware debug view of FIG. 29, however, an “Agent” tab has been selected illustrating the appearance of the Agent tab screen. FIG. 34 is a chart illustrating the data object composition of objects as used by the present invention. DETAILED DESCRIPTION OF THE INVENTION Attention is immediately directed to FIG. 2 which illustrates a digital system generally indicated by the reference numeral 100 including a hub 102 which is manufactured in accordance with the present invention. It is noted that like reference numbers are used throughout the various figures to refer to like components wherever possible. System 100 includes a main loop 104 which uses Fibre Channel protocol. However, it should be appreciated that loops which employ other protocols such as, for example, Token Ring and Fibre Distributed Data Interface (FDDI) may benefit from the teachings herein. Loop 104 interconnects stations S1 and S2 such that digital data in accordance with Fibre Channel protocol standards flows around the loop in the direction indicated by a number of arrowheads. Only two stations are illustrated as being interconnected by loop 104 for purposes of simplicity. Hubs, such as hub 102 are configured with ports by which stations such as S1 and S2 may be connected with loop 104. In the present example, port 1 is used to connect S1 while port 2 is used to connect S2. While the loop typically uses a fiber optic cable to conduct the digital data, the link between a particular port and associated station is not necessarily comprised of a pair of fiber optic cables. Accordingly, different forms of adapters (not shown) may be inserted into the ports, as will be described in further detail at an appropriate point below. It should also be mentioned the interconnection or link between each station and the hub is illustrated as being quite short in the present figure for illustrative purposes only and, in fact, the link may be quite long. Moreover, each station, including its interconnection with the hub and aforedescribed adapter, may be referred to as a lobe on the loop. Still referring to FIG. 2, in accordance with the present invention, hub 102 includes a first embodiment of a highly advantageous diagnostics arrangement generally indicated by the reference number 106. Arrangement 106 is made up of a Fixed Diagnostics Unit (FDU) 108 and a Roving Diagnostic Unit (RDU) 110. It should be appreciated that the FDU and RDU may be configured in a number of different ways in view of this overall disclosure. In FIG. 2, FDU 108 is illustrated in a form which allows it to listen to the digital data flowing around loop 104 at a single point 112 on the loop. RDU 110 is illustrated in a functional manner. That is, RDU 110, in the present embodiment, is shown as being connected with port 1 via a pair of dashed lines 114: However, in this embodiment, the RDU may be commutated selectively between the various ports as indicated by an arrow 116. As shown, the RDU is connected in such a manner as to listen to the data present at a port output point 118. By the term “listen”, non-intrusive monitoring is meant. That is, data present at the point being monitored is observed, but operation of the system is not affected in any way. In view of the foregoing discussions related to FIG. 1 and specifically considering the use of an analyzer, it should be appreciated that the configuration of diagnostic arrangement 106 is highly advantageous. For the moment, it is sufficient to say that the advantages provided by this arrangement primarily derive from the ability to listen at a plurality of points distributed around loop 104. Furthermore, arrangement 106 is considered to be highly advantageous due to the fact that information is obtained and gathered at one location (i.e., within the hub) from all of the monitored points. In this manner, by using features of the RDU and FDU to be described, diagnosis may be performed in view of the system as a whole. Applicants are unaware of this capability heretofore. As mentioned above, loop 104 may have different data present at any of the points between different pairs of the stations distributed around the loop. Therefore, it has been extremely difficult in the past to gain a full understanding of problems such as those described with regard to FIG. 1. The present invention serves to alleviate these problems by initially recognizing the need for collection of data from points distributed around the loop and, thereafter, subjecting this data to analysis. Referring now to FIG. 3 in conjunction with FIG. 2 and having discussed several basic concepts of the present invention from a conceptual standpoint with regard to the first embodiment of the present invention using hub 102, a specific implementation of hub 102 will be described as depicted in FIG. 3. For purposes of clarity, hub 102 remains connected with stations S1 and S2 as is also shown in FIG. 2. For reasons which will become evident, this hub implementation will be referred to hereinafter as the diagnostic loop or inner loop configuration. Accordingly, the diagnostic loop configuration of hub 102 includes a highly advantageous diagnostic loop 130 which is submitted to be unknown heretofore. It should be noted that digital data traveling on the diagnostic loop travels in a direction which opposes the direction that data travels on main loop 104 for reasons given below. The diagnostic loop and main loop each pass through port control circuits PCC1 and PCC2 associated with ports 1 and 2, respectively. PCC1 is indicated by the reference number 140a while PCC2 is indicated by the reference number 140b. Each PCC includes a LOOP_IN (hereinafter LI) and a LOOP_OUT (hereinafter LO) connection interfaced with main loop 104. DIAG_IN and DIAG_OUT (hereinafter DI and DO, respectively) connections refer to the interface points with diagnostics loop 130. Further, each PCC includes PORT_IN and PORT_OUT (hereinafter PI and PO, respectively) connections. When the input or output connection of a particular PCC or the PCC itself is referred to, the appropriate port number designation will hereinafter be appended to the foregoing abbreviations. In addition, the RDU is interfaced in the diagnostics loop using RDU_IN and RDU_OUT connections. The port control circuits include a number of highly advantageous features. One important feature resides in the ability of the PCC's to listen to the data present on main loop 104. That is, the data on the main loop is copied onto the diagnostic loop by one of the PCC's and, thereafter, travels around the diagnostic loop to RDU 110 in a non-intrusive manner such that operation of main loop 104 is not affected, thus implementing the capability contemplated by the present invention requiring non-intrusive monitoring. Referring to FIGS. 3 and 4, details regarding the design of the PCC's will now be described. PCC's have been produced in accordance with the present invention as integrated circuits per the block diagram of FIG. 4 which illustrates a PCC generally indicated by the reference numeral 140. PCC 140 will be described primarily in terms of this block diagram since it is considered that one of ordinary skill in the art may produce this circuit in view of this overall disclosure. PCC 140 includes a plurality of signal drivers several of which are indicated by the reference number 142 (not all drivers are indicated). One by two muliplexers 144a-c, a one by four multiplexer 146 and a Clock Data Recovery Section (CDR) 148. The latter is connected with a low pass filter section 150 indicated within a dashed line. CDR Section 148 serves to recover clock information from incoming data on PORT_IN and retime incoming data to this recovered clock. With regard to details of construction of PCC 140, it is important to note that the data paths defined by the circuitry are high frequency in order to carry the contemplated gigabaud per second data rate. Input and output lines have been labeled consistent with FIG. 3. Thus, LI (LOOP—IN), LO (LOOP-OUT), PI (PORT-IN), PO(PORT-OUT), DI (DIAG-IN) and DO (DIAG-OUT) are readily identifiable. Additionally, a number of selection/control lines are present including CDR_SELN, DIAG_SELN, LOOP_SELN, PORT_SELON and PORT_SELIN. The functions of these various additional lines will become evident below. TABLE 1 Signal Selection (boldface type is recovered data) PORT— PORT— LOOP— DIAG— CDR— PORT— LOOP— DIAG— STATE SEL0N SEL1N SELN SELN SELN OUT OUT OUT 1 1 1 1 1 1 LOW LOW LOW 2 0 1 1 1 1 LOW LOW LOW 3 1 0 1 1 1 LOW DIAG_IN DIAG_IN 4 0 0 1 1 1 LOW LOOP_IN LOOP_IN 5 1 1 0 1 1 LOW LOOP_IN LOW 6 0 1 0 1 1 LOW LOOP_IN LOW 7 1 0 0 1 1 LOW LOOP_IN DIAG_IN 8 0 0 0 1 1 LOW LOOP_IN LOOP_IN 9 1 1 1 0 1 LOW LOW DIAG_IN 10 0 1 1 0 1 LOW LOW DIAG_IN 11 1 0 1 0 1 LOW DIAG_IN DIAG_IN 12 0 0 1 0 1 LOW LOOP_IN DIAG_IN 13 1 1 0 0 1 LOW LOOP_IN DIAG_IN 14 0 1 0 0 1 LOW LOOP_IN DIAG_IN 15 1 0 0 0 1 LOW LOOP_IN DIAG_IN 16 0 0 0 0 1 LOW LOOP_IN DIAG_IN 17 1 1 1 1 0 LOW PORT_IN PORT_IN 18 0 1 1 1 0 PORT_IN PORT_IN PORT_IN 19 1 0 1 1 0 DIAG_IN PORT_IN PORT_IN 20 0 0 1 1 0 LOOP_IN PORT_IN PORT_IN 21 1 1 0 1 0 LOW LOOP_IN PORT_IN 22 0 1 0 1 0 PORT_IN LOOP_IN PORT_IN 23 1 0 0 1 0 DIAG_IN LOOP_IN PORT_IN 24 0 0 0 1 0 LOOP_IN LOOP_IN PORT_IN 25 1 1 1 0 0 LOW PORT_IN DIAG_IN 26 0 1 1 0 0 PORT_IN PORT_IN DIAG_IN 27 1 0 1 0 0 DIAG_IN PORT_IN DIAG_IN 28 0 0 1 0 0 LOOP_IN PORT_IN DIAG_IN 29 1 1 0 0 0 LOW LOOP_IN DIAG_IN 30 0 1 0 0 0 PORT_IN LOOP_IN DIAG_IN 31 1 0 0 0 0 DIAG_IN LOOP_IN DIAG_IN 32 0 0 0 0 0 LOOP_IN LOOP_IN DIAG_IN Attention is now directed to Table 1 in conjunction with FIGS. 3-5. Table 1 indicates signal selections made using any PCC for a number of different combinations of inputs on the selection lines of that PCC while FIG. 5 is a cutaway partial view of the system which primarily shows the PCC's. It should be appreciated that the relatively large number of selection possibilities (i.e., states), evidenced by Table 1, provides a great deal of flexability in the use of the PCC's. As an example, normal loop operation occurs in state 28 in which LI is connected to PO and PI is connected to LO. PCC1, in FIG. 5, is connected in this way as indicated using curved lines 160 such that data passes from the main loop through PCC1, out to the associated station, back to the PCC and then back onto the main loop. Such a station is “inserted” in the loop. Also, in-state 28, DI1 is connected directly to DO1 by a line 162. The purpose of this diagnostics loop connection will become apparent. The flexibility of the PCC becomes evident when one observes that in state 20, like state 28 LI is connected to PO and PI is connected to LO such that data passes through a station wherein the station serves as part of the main loop. S2 is illustrated in state 20 having curved lines 160 interconnecting the main loop with S2. Furthermore, PI2 is connected with D02, as illustrated by a curved line 164, such that loop data from S2 is placed onto the diagnostics loop as well as continuing along the main loop. Thus, state 20 provides for placing data from P1 (i.e., the output of the lobe on which the station resides, onto the diagnostics loop, while state 28 provides for routing the diagnostics loop through the PCC. In this way, data from a station “upstream” (i.e., S2 here) in the diagnostics loop relative to the station being monitored is able to flow to the RDU for analysis. While only two ports/stations are illustrated in the present figure, it should be appreciated that data may pass through any number of PCC's on the diagnostics loop in this manner. Still considering options presented by Table 1 with reference to FIGS. 3 and 6, it is also important to observe that the RDU may place data onto the diagnostics loop for receipt by the PCC's or, more specifically, by a selected one of the stations. For example in FIG. 6, if the RDU is to perform diagnostics on S1, PCC1 may be placed into state 23, such that DI is connected to PO as represented by a curved line 166, LI is connected with LO as represented by a line 168 and PI is connected with DO as represented by curved line 164. It should be appreciated that, in state 23, S1 is effectively removed from the main loop. At the same time, S2 is placed into previously described state 28 such that S1 is effectively placed in the diagnostics loop while S2 remains connected in the main loop and, as such, may operate normally. With the stations in this configuration, diagnosis of S1 using the RDU may proceed in a highly advantageous manner, completely isolated from the main loop. Hereinafter, testing of a module in the above described manner will be referred to as an RDU station diagnosis test. Other states of interest from Table 1 include state 22 and state 7. State 22 allows external loopback of data back to a station with the station out of the loop, while listening to the data with the RDU. This allows for offline diagnostics and is used to support a lobe verification test performed prior to station insertion, as will be described below. State 7 allows for internal loopback testing of a PCC using the RDU to send/receive data for use in hub self testing. It is noted that, in the event that an internal loop-back test is not successful, hub replacement is commonly indicated since the hub is not generally user serviceable. Further details will be provided below regarding the design of PCC's in accordance with the present invention. With reference to FIG. 7, attention will now be directed to other advantages of the present invention. System 100 is depicted during an initialization procedure performed in accordance with the present invention. Accordingly, it will be assumed for purposes of the present example that S2 is the object of a port insert. That is, S2 has possibly just been received within port 2 of hub 102 and wishes to be inserted into main loop 104 necessitating a loop reintialization. An RDU station diagnosis test is performed on S2. This process (not shown here) begins in a first step by verifying that S2 has valid Fibre Channel data by connecting S2 in state 23 and S1 in state 28. While these connections are not specifically illustrated in FIG. 7, the reader is referred to FIG. 6 showing S1 in state 23 and S2 in state 28. It should be appreciated that a signal sent from the RDU to S2 will pass through PCC2, then through S2, back onto the diagnostics loop, through S1 to arrive back at the diagnostics loop. Having received the signal back, this first step performed by the RDU has been satisfied. That is, at this point the RDU knows by performing the RDU station diagnostic test that S2 has valid data input and so is ready to connect S2 into the main loop. Still referring to FIG. 7, as a second step, S2 is connected into the main loop and the monitoring point for the RDU is moved to PCC1. Accordingly, PCC1 is placed into state 20 (described above), as indicated by curved lines 180 within PCC1, while PCC2 is placed into state 19, as indicated by curved lines 182, in which DI2 is connected to PO2 and PI2 is connected to LO2 as well as to DO2. With this arrangement, the RDU can transmit a LIP to S2 via a segment 183 of the diagnostics loop and PCC2. PCC2 (assuming proper S2 operation) receives a response LIP back from S2 and places it onto a main loop segment 184 on which the LIP travels to PCC1. At the latter, the LIP is routed through S1 and then onto DO1 to travel back to the RDU on a segment 186 of the diagnostics loop. In this way, it can be verified by the RDU that the LIP transmitted into S2 is received at S1. Having verified that the LIP has successfully traveled through all of the stations on the loop, the RDU may allow completion of the S2 port insert. In this regard, it should be appreciated that counter-rotation of the diagnostics loop in relation to the main loop is advantageous. As one advantage, this counter-rotation allows the port undergoing an insert to first receive the LIP from the RDU in a manner that is consistent with intuition. Thereafter, the LIP travels through all of the remaining stations on the loop. As another advantage, it is submitted that the counter-rotating diagnostic loop allows insertion of ports according to Fibre Channel loop protocol and that, without this feature, the port insert could be non-compliant. Moreover, if the diagnostics and main loops rotate in the same relative direction and the port to be inserted first receives the LIP (not shown), a segment conflict occurs on the diagnostics loop, which has not been illustrated for purposes of brevity, but which is readily demonstrable by one of ordinary skill in the art in view of this disclosure. Referring now to FIG. 8, another highly advantageous initialization procedure performed in accordance with the present invention will be described. Specifically, an automatic external loop-back test is performed during any port insert. FIG. 8 is a partial view showing S1 as part of system 100. The external loop-back test is depicted under way for S1 with S1 in state 22 from Table 1. State 22 connects PI1 to PO1 and to DO1 while connecting LI1 to LO1, as indicated by a set of curved lines 184. It should be appreciated that the external loop-back test provides for verification of the entire lobe on which S2 resides including the lobe's complex high frequency paths. In fact, because the diagnostics loop is used for monitoring, the integrity of at least a portion of the diagnostics loop is also confirmed. It is submitted that Fibre Channel protocol is completely devoid of this feature, including the automatic implementation contemplated herein. Moreover, Applicant's are not aware of the provision of an automatic external loop-back test in any form of loop protocol that provides for simultaneous monitoring of the looped back data. Such an external loop-back test is effective in the diagnosis of a problem with PCC1. A particular advantage associated with this procedure resides in the fact that the procedure is performed by the unit itself in a rapid manner which is likely to be of great benefit to a system administrator. For example, a system administrator can be notified via a notification generated by the system following a failed port insert, while the failed port is held in bypass mode. This notification may be generated in the form of an email message which is particularly advantageous in instances where the system administrator is monitoring from a remote location. Referring briefly to FIG. 2, it should be appreciated that the present invention may be implemented in an alternative embodiment (not shown) wherein “Port Diagnostics Units” (PDU's) are provided. That is, the combination of the FDU, RDU and diagnostics loop is replaced in favor of a PDU at each port. In this manner, loop data can actually be tracked during its progress around the main loop by the PDU's. It is contemplated that a PDU implementation of the present invention is practical particularly in the form of an AS1C in which the entire hub function is produced essentially as one chip. The introduction of the PDU implementation does not vary the basic concept of the present invention. That is, the advantages derived herein extend from the capability to “listen” at a plurality of points distributed around the main loop. A further advantage is provided, as mentioned, in the form of the ability to simultaneously listen to the distributed loop points. For example, the progress of a specific, individual ordered set can be tracked in its progress around the loop. Having generally described several hub implementations in accordance with the present invention, details with regard to the diagnostics capabilities of the RDU and FDU will now be described. It should be appreciated that these capabilities may also reside in a PDU implementation. One feature incorporated in the RDU and FDU is ordered set detection. Fibre Channel protocol recognizes ordered sets as four ten-bit characters (FC-0). Ordered sets are used, for example, during loop initialization. The present invention monitors a particular group of ordered sets. This monitored ordered set group includes IDLE, LIP, LIP F7, LIP F8 (where LIP is Loop Initialization Primitive), SOF (Start of Frame), ARB (Arbitrate) and OPN (Open). In addition, any other valid ordered set may be specified as USR (User) as well as an Unknown ordered set and K28.5 (comma character) which is the first character that any ordered sets may have in common and, therefore, is useful in a determination that valid ordered sets are present. A number of features are related in a direct way to the ability to perform ordered set detection at the points distributed around the loop, at least one of which will be described immediately hereinafter. Turning to FIGS. 7 and 9, the present invention provides a feature related to the operational state of a Fibre Channel loop. This feature is presently implemented in both RDU 110 and in FDU 108. Presently, five loop states are used herein including INOPERATIVE (the loop is down), INITIALIZING, OPEN-INIT, UP and UP+FRAME (loop is up, with frames). The loop is considered as operational in either of the UP and UP+FRAME states. In FIG. 9, a view is provided which is representative of the physical appearance of the back of hub 100. In accordance with the present invention, a loop status indication LED 200 is provided which is illuminated whenever either of the loop states UP or UP+FRAMES are determined to exist. The presence of each of these two states is established using ordered set detection in conjunction with two additional detectors. The first additional detector detects an ordered set that is unknown and, hence, is referred to as an UNKNOWN detector. That is, the unknown ordered set is a valid ordered set but is not a member of the monitored ordered set group which is detected. The second additional detector is referred to as a LINK-USEABLE detector. In accordance with Fibre Channel protocol, more than a certain number of ones or zeros cannot occur in sequence. This certain number specifies a transition density which is a crude indication of invalid characters on the loop. Irrespective of ordered set detection, loop up indicator 200 is not illuminated unless the transition density has not been violated per the LINK-USEABLE detector. That is, if the link is unusable, the loop is said to be down. If no valid ordered sets are detected including the set specified by the UNKNOWN detector, the loop is also considered as being down. The present invention recognizes that a Fibre Channel system will go to loop up in a sequence of ordered states that is identified through the use of the aforementioned monitored ordered set group. It should be appreciated that the monitored group of ordered sets will appear in sequence as a system moves from the inoperative state to an operative condition and that sequence must occur for proper initialization. Specifically, the first set which is monitored for from an inoperative state is a LIP. Upon recognition of a LIP ordered set, the INITIALIZING state is entered. In the INITIALIZING state, an arbitrate (ARB) or SOF ordered set is anticipated. Once an ARB or SOF is seen, status moves to the OPEN-INIT state. Thereafter, a CLS (close) command is anticipated which is used as a transition to the UP state. It is noted that the close command does not appear in the monitored set group, but is considered as a companion ordered set of the OPN command for use in closing a connection. Arrangement 100 then monitors for data frames (UP+FRAME) by detecting SOF. Thus, once the proper sequence of ordered sets has occurred, indication is provided, for example, via LED 200. Alternatively, the system administrator may receive an indication via software. Another ordered set detection feature that is implemented in RDU 110 is a counter (not shown) that will count any ordered set for which information is desired to be gathered. For example, the counter can count frames at a particular port. If the counter is left active for a particular period of time, the number of data frames sent over that period is detected. In this way, traffic or events of interest can be monitored. Of course, if the data of interest is known to pass all the way around the loop, the RDU may be set to any monitoring point. As another example, the system administrator may wish to determine how much or how often a particular station is using the loop. Assuming that the system administrator wishes to establish this information for a station S7 (not shown) assigned ALPA-7, the counter can be set up to count ARBs or startup frames from S7. In this regard, it should be appreciated that ordered sets are 40 bits in length. The first 20 bits indicate what type of ordered set it is, while the next 20 bits give further details about the ordered set which usually includes the address of the station the ordered set came from. Accordingly, the counter can be set up to either use the ordered set just in terms of its type or to use the ordered set based on all or nearly all of the information available from the 40 bits. For example, only ARB ordered sets from S7 could be counted or, as another example, only ordered sets from S7 “talking” to a station S4 could be counted (not shown). Another feature in accordance with the present invention resides in the ability to capture Arbitrated Loop Physical Addresses (ALPA's) by observing data patterns or communications on a loop. It is noted that the ALPA's are assigned to the various stations that are present on the loop during initialization. More specifically, present during initialization states referred to as OPEN and OPEN-INIT. Through the ability to listen at points distributed around a loop, the present invention is capable of determining which ALPA's are attached to each port. That is, an ALPA map can be generated. There are two methods used to establish the ALPA's connected to each port. In a first method, an ARB command is used. It should be appreciated that the use of ARB commands can reveal all of the active ALPA's on the loop while listening anywhere on the loop. Referring to FIG. 3, in a second method of mapping connected ALPA's, an OPN command is used. When using OPN commands for this purpose, the listening point is moved around the loop to establish in which domain the OPN exists (i.e., where the OPN vanishes). For example, if S1 has an assigned ALPA of 1 and S2 has an assigned ALPA of 2, RDU 110 could first listen at S1. By examining ALPA's with ARB commands, ALPA-1 and ALPA-2 will be seen. Using the OPN ALPA mapper presently under discussion, however, only OPN's for ALPA-2 will be seen. Similarly, if the listening point is switched to S2, only OPN's for ALPA-1 will be seen. The disappearance of the OPN infers that the station at the listening point is assigned that ALPA. Certainty as to that being the correct ALPA is increased, as time passes, when that ALPA continues to be absent at that point. In this regard, a PDU implementation (not shown) is advantageous since the progress of an OPN around the loop can be observed simultaneously at all of the points around the loop. In this way, certainty is increased as to where an OPN disappears. Having introduced the reader to a number of concepts of the present invention, an appropriate juncture has been reached at which some of its advantages can be emphasized. Specifically, it is important to understand that all of the capability discussed is provided in the hub itself. That is, the need for an external analyzer has been virtually eliminated. At the same, time, however, an external analyzer is inherently handicapped since its monitoring is intrusive, as described above. The present invention is inherently powerful based on the capability to monitor a plurality of points distributed around the loop. Other features such as, for example, ordered set detection and the counter are extremely useful in conjunction with this multi-point monitoring capability. It is submitted that such a combination of features has not been seen heretofore. In terms of problem identification, analysis can first be performed on the data to evaluate whether or not there really is a problem. In this regard, there can be conditions that are part of the normal operation of the loop, however, if these conditions persist, then they are a problem. Such problems can be identified with the multi-point data available through consolidation of information. From another viewpoint, the multi-point data is used to establish the status of each of the stations in the loop. A particular station or even the hub itself can be identified as the source of a problem. With status data as to the entire loop including the hub in hand, the status data can be displayed or automatic, predetermined responses may be taken. For example, a defect can be removed. Thereafter, operation of the system may resume automatically. Alternatively, an indication can be provided to a system administrator that the defect has been removed and operation can now be restored. In one feature to be described, beaconing may be employed to identify the actual physical location of a removed defect. Specific details with regard to the display of additional status information will be provided immediately hereinafter. Referring to FIG. 10, a display 202 is shown depicting a site management view generally indicated by the reference number 204. The present example assumes a system having two managed stacks wherein stack 1 includes two hubs and stack 2 includes three hubs. Site management view 204 represents an encapsulation of the status of every device that is within the scope of management. Therefore, at the highest level, all of the managed stacks including stack 1 and stack 2 are indicated by the reference numbers 206 and 208, respectively. Also shown, in the form of elliptical circles, are the loops (each of which uses a hub) associated with each stack as indicated by the reference numbers 210 and 212 for the stack 1 hubs/loops and by the reference numbers 214, 216 and 218 for the stack 2 hubs/loops. It should be noted that the operational status of each loop is indicated by the color of the loop in the present view. For example, an up and operating loop is shown by the color green within the corresponding elliptical circle. If any of the loops are not green, further attention should be directed to these loops, for example, using further status display features of the present invention which are available by “drilling down” from the site management view. It should be appreciated that one advantage of the site management view resides in immediately directing the attention of an observer to problem areas, even in the instance of a system administrator having little practical experience. In this regard, it is contemplated that the site management view may be iconified in a way which makes problems apparent via the appearance of an icon. Turning to FIG. 11 in conjunction with FIG. 10, selection of stack 2, for example by double clicking on it in the site management view of FIG. 10, brings up a stack view 220 on display 202. It is noted that hubs may be considered as being in the same stack by virtue of having some type of connection with regard to their management information. For example, the connection may comprise an out of band management cable. That is, this management data is not present on the loops themselves. Stack view 220 displays hubs 214, 216 and 218 (FIG. 10) labeled as Hub 1, Hub 2 and Hub 3, respectively. The stack view is intended to highlight information from a configuration standpoint. For example, what types of physical connections are present in each hub and whether these connections are optical (shortwave or longwave) or copper. These connection types will be discussed further at appropriate points below. In addition, it is indicated which of the hubs may possibly have management agents in them since the management agent is what provides the information used to make these determinations. A color indicator 222 (the color of which cannot be seen due to format limitations of the present application, as is the case throughout the figures) comprising the background of the stack indicates an overall status derived from the status of each hub. For example, the background is green if all of the hubs are fully functional. Referring to FIGS. 9-12, selection of one of the hubs in stack view 220 leads to a hub view 224 associated with the selected hub. FIG. 12 illustrates this view for Hub 2 of stack 2 (indicated by reference number 216 in FIG. 10). It is noted that additional Hub Views will be provided below. Hub view 224 may also be referred to as a back-of-box view since the image is intended to physically represent the appearance of the corresponding panel on the hub itself. It is noted that a great deal of the information available through the use of the present invention is presented in the hub view. At a glance, any of the ports can be seen including whether each port is in a functional status. Alternatively, it is indicated that ports need attention or a port is in a failure mode. This indication is provided by the background color 226 surrounding each port in gray, green, yellow or red (as noted above, color not illustratable) where gray indicates unused, green indicates functional, yellow indicates the need for attention and red indicates failure. Additionally, a pair of virtual LED's 228 are illustrated associated with each port. The actual LED's corresponding to these virtual LED's are indicated by the reference number 230 in FIG. 9 showing a pair of LED's is associated with each port. It is noted that both virtual LED's 228 and actual LED's 230 can be beaconed to cause the LED's to blink on display 202 as well as on the hub box itself, as will be further described. Thus, a good or bad indication can be provided for each port of the hub based on monitoring in accordance with the present invention. This feature is advantageous, for example, to anyone in helping to locate hardware of interest. In this regard, it is submitted that the capability to reflect the status of the loop and the use of beaconing, as described, have not been seen heretofore. It is also noted that a virtual “Loop Up” LED 232 is provided which corresponds to LED 200 in FIG. 9. That is, virtual Loop Up LED 232 is illuminated whenever LED 200 on the hub panel is illuminated. Other indications include Power OK 234, uC (microcontroller) OK 236 and Fan Fault 238 for which the actual and virtual LED's are indicated using the same reference number. FIG. 13 represents a port detail screen 240 which appears upon selecting one of the ports in FIG. 12. In this example, port 11 of hub 2 in stack 2 has been selected. A port control box 242 is included in the screen which provides four selectable modes under which the port can be operated. The auto mode is configured for maintaining loop integrity and enabling built in recovery functions at a policy level. That is, in the auto mode, ports will not be inserted that will bring the loop down. The auto mode gives the hub full license to make every port insertion go through criteria to maintain loop integrity. In effect, authority is given to screen every module such as, for example, a GBIC (Gigabit Interface/Interconnect Converter) that is plugged into this port prior to its insertion into the loop. That authority is removed, for example, if the Force Bypass mode is selected. In Force Bypass mode, the port will not be inserted irrespective of validity. The Force Bypass mode can be used to perform tests on an already inserted port or a port can be bypassed prior to its initial insertion. It is noted that other diagnostic capabilities can be invoked in the Force Bypass mode, as will be described. Several other modes can be invoked including Loopback and Force Insert. In the Loopback mode, the port receiver is connected directly to the port transmitter such that a station on the port may do diagnostic self testing (see, for example, FIG. 8). In a lobe initialization feature which represents an alternate and more powerful method for testing stations before insertion, the loopback capability built into the port is used to wrap receive back to transmit so as to cause the station to initialize completely before insertion. This feature has the advantage of providing much more confidence that the inserting station is fully functional before impacting the hub and all stations already attached. In the Force Insert mode, a node/station is inserted into the loop irrespective of its operational status. Such a feature may be useful if a node is not behaving well according to the Fibre Channel protocol and it is desired to force that node to be inserted into the loop for observation. For example, the node may not be going through proper initialization. The provision of all of these user selectable modes is highly advantageous with regard to giving the user full control over devices for purposes such as, for example, troubleshooting. In this regard, verification can be performed on devices that are being blocked out for reason of not behaving well. That is, a suspect device can be reinserted to observe whether or not it is bringing down the loop. Still referring to FIG. 13, one feature present in the port detail view is a GBIC display box 244. It is noted that GBIC's have some built in identification information. This information is extracted for display here. The information identifies the specific type of GBIC. For example, a shortwave laser GBIC (as shown), a longwave laser GBIC or a copper GBIC with an HSSDC connector. A state indication 245 within GBIC display box 244 is obtained from both the GBIC and the diagnostic circuitry that is monitoring the port, as described above. A “No Valid Data” indication is illustrated. In this way, it is determined if there is a valid signal and whether or not the node is transmitting valid Fibre Channel characters. A port connect box 246 includes a state indication 248 that is produced by the present invention. While action can be initiated based on no valid data, the present invention further provides for bypassing a node that is in a loop failure state or transmitting LIP F8. For example, if a device is “LIP F8ing”, port connect state box 248 will reflect that condition (not shown). Alternatively, if there is a problem with the transmitter on the GBIC itself, it will be indicated. Referring to FIG. 14, if Vixel logo 250 is selected in the hub view of FIG. 12, a hub sweep view 260 appears on display 202. The hub sweep view is comprised of a consolidated capture of data for all of the ports of the hub displayed in a meaningful way. Data is displayed corresponding to each port or node on the loop. The port numbers are indicated in a row 264. Beneath each port number is a column of boxes labeled to the far left with ordered sets. It should be noted that the monitored group of ordered sets, described above, is displayed forming a majority of the information in the column. Specifically, LIP is indicated by reference number 265, LIP F7 is indicated by 266, LIP F8 is indicated by 268, OPN is indicated by 270, ARB is indicated by 272, IDLE is indicated by 274, SOF is indicated by 276, USR (User Defineable) is indicated by “Match” at 278 and the Other ordered set (Other OS) is indicated by 280. A link useable indication 282 is provided along with a K28.5, comma character, indication 283. Therefore, the presence of an ordered set associated with each port may be indicated. It should be appreciated that, while quite a number of individual data are displayed, a system administrator can discern meaningful information from the display very readily. Even an inexperienced administrator will immediately recognize the value in this display. An experienced administrator, however, will be capable of correlating the data in view of his or her experience. Other displayed data includes a loop state display 284 which indicates whether the loop is up, down or initializing. Presently, an “Up” indication is being given. It is noted that the various display boxes of FIG. 14 may be arranged in any suitable manner and that a warning will come up if a user selects an non-automatic option. With regard to interpretation of sweep display 260, initializing is a normal process that a loop will go through as the loop is starting up. Initialization should occur for a very brief period of time prior to the loop coming into the up or active state. If the loop stays stuck in initialization, the hub sweep view enables one to be able to see which nodes/ports are involved. More particularly, the presence of LIP F8 is displayed. The significance of this loop initialization primitive was described earlier. Therefore, if a node is in a LIP F8 state, from this sweep view one can readily see which is the offending node. Thereafter, mechanisms also built into the hub can be used to automatically recover. It should be appreciated that this display is highly advantageous since for each segment of the loop one can, at a glance, see exactly which data is being transferred. That is, if that segment is in a quiet state, if it's in initializing or if it's in a failure mode. Alternatively, further troubleshooting may be performed using other diagnostic screens to be described below. In this regard, the present invention provides a great deal of single port visibility through the monitoring that can be performed on a single port. By collectively displaying data gathered for all of the ports in a consolidated view, valuable information is provided as to what is actually going on in the loop. It is submitted that such a view is highly advantageous and has not been seen in a Fibre Channel system heretofore. In order to achieve a display such as this in the prior art, the number of ports would at least have to be doubled with analyzers residing at each of the added ports. Sweep display 260 has further implications. That is, by having the information available from the present invention, automatic actions can be implemented based on analysis of the data accumulated. It should be mentioned that sweep display 260 may be presented irrespective of whether a port or roving diagnostic implementation is used to collect the data. Referring to FIGS. 15 and 16, one example of a per port diagnostic screen 286 is illustrated. Port diagnostic screen 286 includes a port diagnostics control box 288, a port selection box 290 and a transmitter control box 292. Using port diagnostics screen 286, it should be appreciated that full path end-to-end verification can be performed from the hub on a lobe. As an example, FIG. 16 illustrates a portion of hub 102 connected with station S1. The lobe consists of the GBIC transceiver which includes a transmitter TXP1 and a receiver RxP1. The lobe further includes a cable or fibers 294 extending from the hub to a node receiver RxS1 and a node transmitter TxS1 at the station. The latter may also include a loop state machine 296 that is diagrammatically indicated by an arc extending between the station transmitter and receiver. It is noted that during the full path verification, the hub bypasses the station, as illustrated (by LU1 being connected to LO1), such that the node is isolated from the main loop. In the absence of loop state machine 296, data that is sent to the station from the hub is expected to return to the hub so as to perform an end-to-end connection verification. In the presence of loop state machine 296 and being cognitive of the loop state machine implemented, however, an ordered set can be sent to the station which should return a different response. Thus, the operation of the loop state machine is verified as well as the connections in the lobe. The ability is provided to transmit to a port, receive on that same port and detect what ordered sets were seen on the receive. Lobe verification is highly advantageous with regard to diagnosis since there are numerous opportunities for points of failure around the lobe's path. For example, there may be a bad laser or a plug-in connection that is not fully seated. It should be appreciated that this verification is more powerful as compared with an external loop-back test. In an external loop-back test (not shown), the station itself may do some verification with the port in bypass mode. The node would initiate the process and would transmit from TxS1 to RxP1. The hub will then loop that data to TxP1 to then pass the information back to S1 via RxS1. The end-to-end lobe verification test of the present invention is considered to be highly advantageous (1) in verifying the node state machine without external interaction and (2) because the configuration on which the verification is successfully performed will not be physically disturbed for purposes of entering normal operation. That is, the configuration will not be disturbed upon entering normal operation. It is submitted that this feature has not been seen heretofore. While port diagnostics screen 286 provides a visual display for purposes of manipulating this lobe verification, the present invention contemplates the use of lobe verification in an automatic process. For example, a capability may be provided for an operator to do a full configuration verification by pushing one button. In response, the system would then go out, bypass every node and do the full path verification on each node. Thereafter, a display (not shown) of the configuration verification results can be provided. Still referring to FIGS. 15 and 16, another capability is provided using transmitter control box 292. Through the ability to turn hub transmitter TxP1 on and off, another form of verification is provided. Specifically, node verification is provided in response to turning the port transmitter off to a node. If TxP1 is turned off, S1 should respond with a LIP F8, or the loop failure character, thus, serving as another mechanism of verification. The capability to selectively turn off a transmitter whereby to solicit a LIP F8 from a connected station may be referred to hereinafter as a transmit disable feature and is considered as being highly advantageous. Turning now to FIG. 17, a Fibre Channel system 300 is illustrated which includes stations S1-S5, a hub H1 and a loop L1. Stations S1 and S2 are connected in L1 while Stations S3-S5 are connected using H1. For purposes of the present example, it will be assumed that two tape backup operations are occurring in which S3 and S5 are both tape devices and S1 and S2 are servers. One backup is from S1 to S3 while the other backup is from S2 to S5. It should be appreciated that Fibre Channel is not a broadcast media. That is, without the hub of the present invention, there is no visibility to all data at all points in a loop. In addition, only two devices can be “talking” at once to each other using a loop. This holds with the aforementioned tape backups going on, since only two nodes can have control of the loop and be transferring data at any one time. Therefore, the two backup operations are in total contention for the bandwidth of the loop at this point in time. Assuming further that H1 is manufactured in accordance with the present invention, at least the ordered sets described above can be counted. Startup Frames (SOFs), for example, show data going through while ARBs show a node gaining control of a loop. By looking at these specific pieces of data, an indication may be provided that there is contention or as to the amounts of data that are being transferred such that, upon analysis of the data, recommendations can be made to either change the time assigned for one of the backups or to segment one backup onto another loop (not shown) since the simultaneous backups tend to slow one another down, as well as to prohibit any other use of the system. In essence, this feature is provided by using gathered information to give one a picture of the traffic or the data frames between the modules on the loop. Still referring to FIG. 17, it is important to understand that information relating to S1 and S2 is provided despite the fact that loop L1 is not managed. In other words, determinations are made regarding a hub or a loop in which H1 is not actually physically directly monitoring the information on that remote loop or hub. These determinations as to the utilization of the remote loop can be made, however, because the hub of the present invention is connected to the remote loop. Utilization may be displayed, for example, in the form of a tachometer style gauge (not shown). Other features may be included such as a threshold for alarming purposes. It should be appreciated that the addition of a hub configured in accordance with the present invention is highly advantageous when added to an “unmanaged” system. Particularly, diagnostic capability will be provided for the existing installation as well as for components connected directly to the new hub. In the example of FIG. 17, with regard to unmanaged loop L1, managed hub H1 may not necessarily be able to identify whether it is S1 or S2 that is misbehaving on the unmanaged loop. However, a problem could certainly be isolated to the port of H1 with which the unmanaged loop is connected. It is submitted that these features with regard to visibility of utilization and congestion are highly advantageous and have not been seen heretofore. Referring to FIG. 18 and having gone through a number of different displays, status indications and information displayed, a description will now be provided regarding details as to how these features are implemented using a data management arrangement 320. Initially, information is collected by a hub data collection section 322 which represents all of the hardware “hooks” that are built into hub 102 (FIGS. 2 and 3) manufactured in accordance with the present invention. This information is stored in a data repository 324 that is resident on a management card (not shown) that is built into the hub. The data is stored in an SNMP mid-structure which is a standard management acquisition tool in networking. It should be appreciated that the available data stored in the memory itself provides the advantages herein (i.e., based on the origination points of the data) in conjunction with its subsequent analysis. The data is transferred via a LAN connection 326 in response to a host poll 327 which is generated by a host system that is not illustrated for purposes of simplicity. It is noted that host poll 327 and the remaining, as of yet undescribed portions of FIG. 18 relate to the method steps implemented within the host system. The information is polled in response to a request by an application running on the host system. That is, data repository 324 serves as an SNMP agent which collects the information in response to the host request. While FIG. 18 illustrates a poll driven system, it should be appreciated that an event driven system is also contemplated. Referring to FIGS. 10-13 in conjunction with FIG. 18, the host polls information from the hub (or hubs) and will poll in an automatic poll 328 all data generically unless the system is in a diagnostic mode. Therefore, the polled information is used in site management view 204 (FIG. 10), stack view 220 (FIG. 11), hub view 224 (FIG. 12) and port detail screen 240 (FIG. 13). The poll of this information is performed at a regular interval which is usually resettable. Generally, the interval may be set from five seconds to each hour. The information is status information which may include, for example, whether a port has been bypassed and if the port has a signal. Thus, the information that is displayed in FIGS. 10 through 13 is polled continuously. Attributes of the data are assigned to a hierarchy of objects within the system. For example, attributes are assigned to a hub object, a port object or a stack object. Each object is based on knowledge of what components the particular object is composed. That is, a port “knows” that it has a signal and a GBIC may be associated with the port. If another port does not have a GBIC, the lack of a GBIC is actually an attribute of that other port. If a port does have a GBIC, then there are characteristics of the GBIC that are available. As further examples, a hub is comprised of ports and a stack is comprised of hubs. Referring to FIGS. 10-14 and 18, certain characteristics are observed in looking at the information that is monitored. For instance, if a port goes into a bypass mode, it should be reported why the port went into that bypass mode. This forms part of the information that is displayed on a regular basis. It should be appreciated that in a diagnostic mode a different type of mechanism comes into play. For instance, when the hub sweep view of FIG. 14 is polled up, this different type of mechanism is employed. While information will still be polled, control information will be sent as well. Thus, if hub sweep view 260 (FIG. 14) is initiated, the hub will use its detector arrangement (i.e., RDU or PDU's) to get information for each port such as the different ordered sets described above. This information will be displayed and observed for the presence of a port in LIP F8. If the latter occurs, an indication is provided that the port transmitting LIP F8 is in a failure status and needs attention. For example, if such a port is in a forced insert mode, the entire loop will be brought down. The status of the port can be reflected all the way up to the loop level (FIG. 10) while, if the port number is displayed, the background of the port is highlighted to reflect status. For the LIP F8 failure status, the background highlight is red. Color highlights are represented in monochrome form around ports 2, 3, 5, 9, 10 and 11 in FIG. 14. In sum, two forms of diagnostic activity occur. The first is automatic poll 328 which is auto-running all of the time while the second is an intrusive/on-demand poll beginning with step 329 that occurs on demand. The automatic poll monitors all components and objects in the system using a generic health associated with each. This generic health may be reflected up, for example, with the occurrence of a LIP F8, as described. The on-demand poll is used in more detailed or specific monitoring (FIG. 14) and will be described in further detail hereinafter. The present invention also contemplates the use of automated diagnostics 330, as mentioned above with regard to event driven diagnostics. Referring to FIG. 18, the on-demand diagnostics operate first by detecting all ports in step 329 to determine which ordered sets are going past each port. In this way, a determination is made as to whether or not the loop is functional. More specifically, if OPNs, ARBs, and startup frames (SOF) are going past, these are valid, operational loop ordered sets. In contrast, if there are loop initialization primitives going around for longer than a very short period of time (e.g., a second would be a long time), the loop is stuck in initialization which will be reflected up through indications. Thus, in step 332, if LIP's occur for greater than some predetermined interval, health indication is changed in a “change health status” step 334 for display purposes. Other notification mechanisms may be provided, as well. In step 336, if LIP F8 is detected, step 338 changes the health status to the failure mode. While the present discussions are centered upon Fibre Channel, it is considered that the method of the present invention can be used in other systems. That is, the characteristics of the data in a particular system may allow provisions for the same sort of detection capability. For example, if detection were performed in other protocols such as in an Ethernet hub in the disclosed manner (at the bit level monitoring non-invasively at distributed points), it is submitted that this method is new. As described above, IDLE characters are included in the monitored group of ordered sets. A discussion will now be provided as to a number of features that are available as a result of idle detection coupled with the overall monitoring configuration of the present invention. Initially, it is noted that if an idle mode is present (i.e., idles are being passed around a loop by the stations connected therein) and a cable is cut, for example, to a node, that node or station will begin transmitting LIP F8. In accordance with the present invention, that node will automatically be bypassed such that the quiet state of the loop is restored. In another feature, the presence of essentially nothing but idles on a loop indicate that a loop is not being utilized. If a pattern develops, for example, every evening between 10 p.m. and 2 a.m. nothing but idles are seen, an opportunity is provided for performing activities such as backup. Thus, recommendations can be made for these quiet times to do batch processing so as to better utilize the data link. In still another feature, the reader is reminded of the foregoing discussion relating to detection of valid Fibre Channel characters. If a node starts corrupting IDLE characters, the present invention will detect the fact that these are not valid IDLE characters. In response, the node which is corrupting the IDLEs will automatically be bypassed. It should be appreciated that this feature is highly advantageous. By proactively intervening upon detection of the corrupted IDLEs and, thereupon, disallowing the offending node from participating, there is no loss of actual data. Thereafter, a notification may be provided with regard to the occurrence of the corrupted IDLEs. Attention is now directed to FIG. 19 which illustrates a Fibre Channel system produced in accordance with the present invention, generally indicated by the reference number 350, for purposes of a discussion of topology mapping in accordance with the present invention. System 350 includes hubs H1 and H2 manufactured in accordance with the present invention. Station S1 is connected to port P1 of H1 while station S2 is connected to port P2 of H2 and station S3 is connected to Port P3 of H2. Port P2 of H1 is connected to port P1 of H2 forming a hub to hub connection. It is assumed that ALPA 1 is assigned to S1, ALPA 2 is assigned to S2 and ALPA 3 is assigned to S3. It should be appreciated that ALPA detection can be applied, as described with regard to FIG. 3, to determine which ALPA's are connected to each port. In the present example, ALPA mapping, in and of itself, will correctly show that ALPA 1, or S1 is connected to P1 of H1. By running an ALPA map on H2 port 1 from H1 port 2, however, ALPA 2 and ALPA 3 (i.e., S2 and S3) will be seen as connected to H1 port 2. In this regard, it is apparent that ALPA mapping does not reveal devices that may be intermediately connected between the stations. Accordingly, it is an objective of the present invention to perform topology mapping identifying intermediately connected devices. In one topology mapping feature, the present invention includes an arrangement for identifying hubs to other hubs such that, if two of these managed hubs are connected together, one hub will recognize that it has a managed hub connected to it and relay that information to a management application. Knowledge of the hub to hub connection will permit the correct locations of S1 and S2 to be identified. This feature is facilitated through identification/serial numbers that are built into the hubs. The transmit disable feature described with regard to FIG. 16 is highly advantageous for use in another topology mapping feature. Specifically, one method used in accordance with the present invention is to check response to the transmit disable feature. If an attachment is a station, it will respond with a LIP F8. In other words, receipt of LIP F8 in response to a transmit disable confirms the presence of a station on the particular lobe served by the disabled transmitter. If, however, a prior art hub rather than a station is on the particular lobe served, the hub will not respond with LIP F8. Still another topology mapping feature is provided which is also submitted to be highly advantageous and which is designed for use with managed hubs in accordance with the present invention. In this feature, following an attachment request received by a managed hub, the managed hub will transmit a burst of LIP F7 to the requesting connection prior to insertion. If the attachment request is from a station, the station will respond to the burst with LIP F7 followed by a stream of IDLES for 15 milliseconds. During the 15 millisecond period, an ARB FB is transmitted to the requesting connection. If the requesting connection is a station, the ARB FB will not return to the hub. Alternatively, if the connection is a hub, the ARB FB will return to the hub. In the event that the ARB FB is returned, the hub will attempt to exchange serial number information via special ordered sets. If the attaching hub is another managed hub manufactured in accordance with the present invention, a serial number other than the first hub's will return. Conversely, if the attaching hub is an unmanaged hub, the serial number of the first hub will return. Therefore, one advantage of this feature is the capability to gather enough information to describe the sequence of connection of hubs by serial number. Once the sequence can be detected, it is also possible to determine if hubs are connected improperly and report problems. It should be appreciated that a significant challenge for system administrators concerning complex configurations is to confirm that the wires/fibers got connected as intended. This level of topology mapping provides the needed feedback. In sum, with regard to the topology mapping features described thus far, ALPA mapping allows determination of the ALPA's that are connected to a port. The transmit disable feature, in which the transmitter to the connection is turned off before the connection is allowed on the loop, allows identification as to whether the device on the connection is a station or another hub. Identification of serial numbers of other hubs allows for locating managed hubs and providing their identification numbers. Referring to FIG. 3, it should be appreciated that hub 102 of the present invention is a repeated hub. Data comes into the hub serially and goes out serially with no delay or imperceptible delay. The hub of the present invention may be an elastic device. This elasticity may be in either in the FDU or RDU 110. In this regard, an elastic FDU 108a is illustrated by a dashed line in a series connection with main loop 104. It is noted that RDU 110 may be elastic, as shown. Data comes into the hub serially, gets converted from serial to parallel, and then is clocked by a separate clock to retime the data. It should be appreciated that the hub of the present invention should be elastic because, depending on the difference between the incoming clock and the local clock, the hub may have to either insert words or delete words. The term elasticity describes absorbing the difference between the clock signals, retiming the data and resetting the jitter to zero. More importantly, what is added is the ability in the hub to insert ordered sets or frames into the data stream and then also remove the inserted data from the data stream without interrupting the normal flow of data. For example, an ordered set can be inserted onto the loop which then can go through a number of devices and come back to the hub to then be removed such that the inserted ordered set does not continue to circulate. Since a request is inserted, it can also be established when the request returns to the hub. Therefore, by observing such a request on one lobe using the RDU, it can be determined what is connected on the lobe as well as the length of the connection since the delay in return can be timed. Referring to FIG. 19, as previously discussed, ALPA mapping using OPN's allows for locating devices that are quiescent. In other words, locating devices that are not open and are not arbitrating for the loop. For example, if S1 is quiescent, it will not send out ARB's or be opened by another device. Therefore, an ALPA map based on active devices will not see S1. The proactive approach of the present invention permits sending out queries to any station to elicit a response, whether the station is active or not, in performing topology mapping. As mentioned, in order to insert and remove these queries, elasticity is provided within the hub with the additional benefits of retiming the data and reseting the jitter to zero. For example, in FIG. 3, elastic FDU 108a retimes data and resets jitter between PCC1 and PCC2. Attention is now directed to FIG. 20 for purposes of a discussion of hot cascading performed in accordance with the present invention. FIG. 20 illustrates a system manufactured in accordance with the present invention and generally indicated by the reference number 400. System 400 includes hubs H1 and H2 wherein at least H2 is produced in accordance with the present invention. Stations S1 and S2 are connected to H1 while stations S3 and S4 are connected to H2. Initially, it is assumed that the hubs are not connected such that two loops are operating separately. Thus, S1 and S2 may be assigned ALPA 2 and ALPA 1, respectively, on H1. At the same time, S3 and S4 may be assigned ALPA 1 and ALPA 2 on H2. Cascading itself is the process of connecting the hubs to one another via a connection path “A”. Hot cascading denotes the fact that the separate loops are already active and the addressees (ALPA's) are already assigned on the separate loops present on H1 and H2. However, as is the case here, it should be appreciated that the ALPA's may be the same for the stations on each loop. That is, both S2 and S3 are assigned ALPA 1 and both S1 and S4 are assigned ALPA 2. Therefore, closing connection A can have disastrous results unless special precautions are taken. For example, it is desirable to avoid events such as data intended for ALPA 2 on H2 to be written to ALPA 2 on H1. As another example, if S2 with ALPA 1 tries to send a command to ALPA 2 on H1 (i.e., S2), it can be seen that because of the direction of the loops the first station having ALPA 2 that this data will encounter is S4 on H2. Thus, it should be assured that such events do not occur as a result of hot cascading. The present invention provides two methods for performing hot cascading, as will be described immediately hereinafter. Referring to FIG. 21 in conjunction with FIG. 20, a first hot cascading method is generally indicated by the reference number 420. The basis of this method is to reset connection A from H2 prior to insertion and, hence, it may be referred to as a “reset connection” method. Method 420 begins with step 422 in which H2 listens for valid input on Rx of its P3. Thereafter, in step 424, LIP F7 is transmitted from Tx of P3 on H2. When the LIP F7 returns to H2 at P3(Rx), it is known that the remote H1 loop has returned the LIP, is operating properly and, therefore, is in a position to reset. Step 426 is then entered in which the LIP F7 continues to be transmitted from P3(Tx) of H2 while listening on P1(Rx) of H2 for the LIP F7 to return. Following return of the LIP F7, in step 428, the LIP is released on P3(Tx) of H2 and normal loop data is transmitted therefrom. Referring to FIGS. 20 and 22, a second hot cascading method is generally indicated by the reference number 440. The basis of the second method is to reset H2 first and, hence, it may be referred to as a “self-reset” method. Method 440 begins with previously described steps 422 and 424. Following step 424, step 442 is performed in which LIP F7 is transmitted on P2(Tx) of H2 while listening for the LIP F7 at P1(Rx) of H2. As compared with method 420, in this instance, the LIP is transmitted upstream from the new connection (i.e., connection A) so as to reset H2 prior to H1. Thereafter, in step 444, loop data is transmitted on P3(Tx) of H2 with P3(Rx) of H2 connected into the loop. That is, the new connection is allowed in while transmitting the LIP F7. Following step 444, step 446 transmits normal loop data on P2(Tx) of H2. Referring to FIG. 2, RDU 110 also utilizes methods for diagnosing system failures outside of hub 102. In a first detection feature, the ability to detect a CRC (Cyclic Redundancy Code) error is included so as to detect a data frame with a bit error entering the hub. In addition, because the RDU identifies the error to a hub port, the error domain is visible and the administrator therefore knows which connection to explore. Therefore, this feature is useful to a system administrator in determining if stations are introducing errors. In a second detection feature, the RDU also captures the source address (ALPA) of the bad data frame. The ALPA information combined with the port identification allows for further narrowing of the source of the error. Isolation of the error may be accomplished by identifying which ALPAs show errors and which do not. The boundary has a strong possibility of being the problem spot. In a third detection feature, invalid Fibre Channel Words are identified. This feature is useful in that invalid Fibre Channel Words are an indication of bit errors on a physical link both inside and outside data frames. An invalid word indication would occur if a bit error occurred between the last station and the RDU. This feature is useful if a fiber, transmitter or receiver is intermittent. It should be appreciated that all of these detection mechanisms can be collected and displayed in a persistent mode to allow capturing and displaying occurrences that are very low in frequency. A real time display would blink on and off so quickly as to be invisible to the administrator. Using the specification to this point and FIGS. 2-22, it is considered that one of ordinary skill in the art may readily practice the present invention in view of the teachings therein. However, for further explanatory purposes, the various configurations and methods disclosed thus far will be described in more detail in conjunction with FIGS. 23-34. It is noted that the term Wizard refers to a hub manufactured in accordance with the present invention, while the terms Apprentice and Magician refer to management method configurations operating in accordance with the present invention. Immediately hereinafter, a description will be provided of an embodiment of a Port Control Integrated Circuit (PCC) manufactured in accordance with the present invention and suitable for use in PCC embodiments of the invention described above. Thereafter, documentation will be provided with regard to management including specific display provisions. 1.0 Purpose The purpose of this description is to define the electrical, mechanical and environmental requirements for a Fiber Channel FC-AL Hub Integrated Circuit. 2.0 Scope This description is limited to the definition of the requirements of the Integrated Circuit specified herein and to no other Integrated Circuit. 3.0 Applicable Documents/References ANS1 X3.272-199×Fibre Channel Arbitrated Loop X3T11/Project 960D/Interface (FC-AL) Rev. 4.5 TR ANS1 X3.XXX-199×Fibre Channel—Methodologies for Jitter Specification Rev. 1.0 Draft F draft Proposed X3 Technical Report (Jitter Working Group) 4.0 Electrical Requirements TABLE 4.1 Absolute Maximum Ratings (VEEE, VEET, VEEG, VEEP = GND) Symbol Description Min. Typ Max. Unit Comment Vcc Power supply −0.3 4 V voltage VI_T TTL DC input −0.5 5.5 V voltage VI_E ECL DC input Vcc − 2 Vcc V voltage II_E ECL input voltage −2 2 V between differential signal IOH_T TTL output current −20 0 mA (High) IOL_T TTL output current 0 20 mA (Low) IO_E ECL output current −30 0 mA Ta Ambient −55 70 C. Under bias temperature Tstg Storage temperature −65 150 C. TABLE 4.2 Recommended Operating Conditions Symbol Description Min. Typ. Max. Unit Comment Vcc Power supply 3.135 3.3 3.465 V 3.3 V + 5% voltage Ta Ambient 0 70 C. temperature TABLE 4.3 DC Characteristics (over recommended operating conditions) Symbol Description Min. Typ. Max. Unit Condition VIH_T Input HIGH voltage (TTL) 2 5.5 V VIL_T Input LOW voltage (TTL) 0 0.8 V IIH_T Input HIGH current (TTL) 20 μA Vin = Vcc IIL_T Input LOW current (TTL) −400 μA Vin = 0 VOH_T Output HIGH voltage (TTL) 2.2 Vcc V IOH = −0.4 mA VOL_T Output LOW voltage (TTL) 0.5 V IOL = 2 mA VIH_E Input HIGH voltage (ECL) Vcc − 1.17 Vcc − 0.88 V VIL_E Input LOW voltage (ECL) Vcc − 1.81 Vcc − 1.48 V VIS_E Differential input voltage 200 1000 mV AC coupled swing (ECL) VOH_E Output HIGH voltage (ECL) Vcc − 1.05 Vcc − 0.81 V 50 ohm to Vcc − 2 V VOL_E Output LOW voltage (ECL) Vcc − 1.81 Vcc − 1.55 V 50 ohm to Vcc − 2 V Icc Supply current 123 154 mA Outputs open Pd Power dissipation 406 534 mW Outputs open TABLE 4.4 AC Characteristics (over recommended operating conditions) See also FIG. 4. Symbol Description Min Typ. Max. Unit Conditions Tir_RC Input TTL rise time of REFCLK 4.8 ns 0.8 V to 2.0 V Tif_RC Input TTL fall time of REFCLK 4.8 ns 2.0 V to 0.8 V Tor_T Output TTL rise time 3.5 ns 0.8 V to 2.0 V, CL = 10 pf Tof_T Output TTL fall time 3.5 ns 2.0 V to 0.8 V, CL = 10 pf Tor_E Output ECL rise time 400 ps 20% to 80%, CL = 2 pf Tof_E Output ECL fall time 400 ps 20% to 80%, CL = 2 pf SDR Serial Data Rate 1062.5 MBd 1.0 UI = 941 ps RC_TOL REFCLK Frequency Tolerance 100 PPM 53.125 MHz REFCLK RC_DC REFCLK Duty Cycle Tolerance 10 % X TJT Total Jitter Tolerance, pk-pk, 10−12 BER 0.7 UI TJT = FDJT + DJT + RJT X FDJT Frequency Dependent Jitter Tolerance, 0.1 UI LPF R/2 = 62 ohm, pk-pk, 10−12 BER C = 0.1 uf, Note 1 X DJT Deterministic Jitter Tolerance, pk—pk, 10−12 0.38 UI LPF R/2 = 62 ohm, BER C = 0.1 uf, Note 1 X RJT Random Jitter Tolerance, pk—pk, 10−12 0.22 UI LPF R/2 = 62 ohm, BER C = 0.1 uf, Note 1 X DJout Deterministic Jitter Output, pk—pk 0.02 0.07 UI ±K28.5 serial data, 637 KHz HPF, LPF R/2 = 62 ohm, C = 0.1 uf X RJout Random Jitter Output, rms 0.010 0.011 UI 00110011 serial data, rms 637 KHz HPF, LPF R/2 = 62 ohm, C = 0.1 uf X 8CRJout Accumulated Random Jitter Output, rms, 0.011 0.0125 UI 00110011 serial data, 8 Cascaded ICs (Port_in to Loop_out) rms 637 KHz HPF, LPF R/2 = 62 ohm, C = 0.1 uf X JXFR_PK Jitter Transfer Peaking 0.2 dB 00110011 Input, LPF R/2 = 62 ohm, C = 0.1 uf X JXFR_3dB Jitter Transfer 3 dB Bandwidth 650 850 KHz 00110011 input, LPF R/2 = 62 ohm, C = 0.1 uf X Tbs Bit Sync Time 2500 bit FC IDLE Pattern X Tfa Frequency Aquisition Time 2000 usec LPF C = 0.1 uf X LDR Lock Detect Range −2 +2 % Frequency Difference Between Recovered Clock and Refclk X PLL Lock Operation Auto Note 2 Note 1: Fibre Channel Jitter Tolerance Mask from Jitter Working Group (see section 3.0). Note 2: Autolock operation desired, but Jitter performance and Locking behavior is more important. TABLE 4.5 Function of LOOP_OUT (see also FIG. 4) LOOP_SELN LOOP_OUT H Recovered Data L LOOP_IN TABLE 4.6 Function of DIAG_OUT (see also FIG. 4) DIAG_SELN DIAG_OUT H Recovered Data L DIAG_IN TABLE 4.7 Function of PORT_OUT (see also FIG. 4) PORT_SEL0N PORT_SEL1N PORT_OUT H H Low L H Recovered Data H L DIAG_IN L L LOOP_IN TABLE 4.8 Function of Recovered Data (see also FIG. 4) PORT_SEL0N PORT_SEL1N CDR_SELN Recoverd Data H H H Low L H H — H L H DIAG_IN L L H LOOP_IN H H L PORT_IN L H L PORT_IN H L L PORT_IN L L L PORT_IN 4.9 Selection of Signal (Note: for Selection of Signal see Table 1 above) 5.0 Mechanical Specifications 5.1 Pin Description (see also FIG. 4) Name Pin No. Type Description X REFCLK 1 I_TTL Reference Clock: When LKREFN is Low or CDR input frequency Is unlocked, PLL locks to REFCLK LKDT 2 O_TTL PLL Lock Detector: When PLL doesn't lock, it is Low VEET 3 PS Ground for TTL I/O: 0 V. DIAG_IN 4 I_ECL (Diff) Serial data output. (See FIG. 1). DIAG_INN 5 VCCE 6 PS Power Supply for ECL I/O: 3.3 V ± 5% LOOP_IN 7 I_ECL (Diff) Serial data input. (See FIG. 1). LOOP_INN 8 VEEG 9 PS Ground for internal logic gate: 0 V. PORT_IN 10 I_ECL (Diff) Serial data input. (See FIG. 1). PORT_INN 11 LKREFN 12 I_TTL Lock to Reference. An active Low input, LKREFN Causes the PLL lock to the REFCLK VEEP 13 PS Ground for PLL: 0 V. LPF1 14 EX Connect to external Loop Filter. LPF2 15 EX Connect to external Loop Filter. VCCP 16 PS Power supply for PLL: 3.3 V ± 5%. PORT_SEL1N 17 I_TTL Selection for PORT_OUT. (See Table 1) PORT_SEL0N 18 VEEE 19 PS Ground for ECL I/O: 0 V. PORT_OUTN 20 O_ECL (Diff) Serial data output. (See FIG. 1). PORT_OUT 21 VCCE 22 PS Power supply for ECL I/O: 3.3 V ± 5%. LOOP_OUTN 23 0_ECL (Diff) Serial data output. (See FIG. 1). LOOP_OUT 24 VCCG 25 PS Power supply for internal logic gates: 3.3 V ± 5%. DIAG_INN 26 I_ECL (Diff) Serial data input. (See FIG. 1). DIAG_IN 27 LOOP-SELN 28 I_TTL Selection for LOOP_OUT. (See Table 1). DIAG_SELN 29 I_TTL Selection for DIAG_OUT. (See Table 1). CDR_SELN 30 I_TTL When Low, PORT_IN is selected for CDR. Notes: See FIG. 23 which illustrates an integrated port control circuit manufactured in accordance with the present invention and generally indicated by the reference number 460. X left of table indicates that this is different or not included in preliminary spec. TABLE 5.2 Pin Type Definition Type Definition PS Power supply or ground. I_TTL Input TTL O_TTL Output TTL I_ECL Input ECL O_ECL Output ECL EX External circuit node. 6. GUI Requirements The primary purpose of the GUI is to enable the user to easily configure and manage one or many stacks. This functionality breaks down into two general categories, multiple stack (device) management and problem (fault) detection and isolation. The device management is focused on viewing the status and controlling physical devices and fault management is focused on viewing the current state of a loop and the connections to it. In managing the stacks there is a natural hierarchy: stacks, mgmt, hubs, ports. In problem detection and isolation information for loop states the hierarchy is: loops, mgmt, hubs, ports. The GUI will present these “cuts” or views into the data. The overall requirements of the GUI are: GUI must be intuitive, easy to use, and useful Help system Multiple Stack device management—ability to view ID, status and controls for any manageable item Site view Single stack view Mgmt view Hub view Port view Problem detection and isolation—ability to view how stacks and loops are connected and health information Site view Single loop view Mgmt view Hub view Port view Must provide an Ethernet SNMP interface Must be localizable Must interface with Apprentice Must provide event logging 6.1 Site View This view will present all active Mgmt cards and all loops associated with each card which will give the user a one screen presentation of the health of all managed stacks and their loops. Since, each managed stack must contain at least one management card and only one card can be active within a management stack, the highest level view will present the active card within each stack and each card presented in this view will be indicative of the worst state of the corresponding stack of hubs. In the same respect, the loops displayed will be presented in a way to reflect their current state (active, should investigate, down). The user needs the ability to display and modify identifying information for both stacks and loops. The requirements for this view are: Display all manageable/monitorable items stacks loops Identification of all manageable stacks by active mgmt card IP MAC domain name user supplied name Show worst case state (active, should investigate, down) of all manageable stacks Indicate number of hubs in each stack Ability to drill-down on any active Mgmt card for more information on the stack Show monitorable loops in each stack Identification of all monitorable loops user supplied name Show current state (active, should investigate, down) of all monitorable loops Indicate number of nodes on loop Ability to drill-down on any loop for more loop information Some future requirements are: Indicate primary In-band management links NOT just using thickness of connection Indicate secondary In-band management links Display In-band Magician management stations Future devices 6.2 Single Stack View This view will show all the hubs in a selected stack but will not necessarily reflect the physical ordering of the hubs. This logical stack configuration will show any cascaded hubs and their associated ports within the stack. Cascading of the hubs allows multiple hubs access to the same loop and within a stack of hubs, it is possible to have one or more loops configured in the stack. Each port on a hub can be attached to a node, a loop of nodes such as a JBOD, or an unmanaged hub. The requirements for this view are: Display manageable hubs in stack selected Indicate which hub has the active Mgmt card Show worst case state of ports for each displayed hub Display identification of each hub serial # Indicate presence of Mgmt card in any hub, active or slave Display identification of all Mgmt cards present MAC IP user supplied name Show hub cascades Indicate connections outside of managed stack If another hub, allow drill-down of stack Clouds=other things with >1 ALPA 6.3 Loop View Within a loop, it is possible to have one or more stacks configured in the loop. Each port on a hub can be used to attach another hub, cascaded, into a single loop or each hub can be its own isolated loop or any other combination of hub connections as long as there is no more than one loop per hub. Each port on a hub can also be attached to an unmanaged device such as a JBOD. This view will show the logical managed loop topology of the selected loop. The requirements for this view are: Show all manageable/known? items in loop selected hubs clouds=JBOD, rest of loop, other things with >1 ALPA label unmanaged hub cloud? Indicate which hub has the active Mgmt card Show worst case state of ports for each displayed hub Display identification of each hub serial # Indicate presence of Mgmt card in any hub, active or slave Display identification of all Mgmt cards present MAC IP name Display any loop info available throughput # of link up/link down # of ARBs registration Display node info per port ALPA list user supplied name user supplied WWN user supplied device type user supplied manufacturer user supplied location 6.4 Mgmt Card View This view should give all pertinent info for a selected management card and provide mechanisms to modify the configuration of the selected Mgmt card. The requirements for this view are: Display Mgmt card identification information MAC IP HW revision FW revision Indicate state of Mgmt card Allow user to force this Mgmt card to be active 6.5 Hub View This view will provide status and control information about each hub in a managed stack or loop and will provide mechanisms to modify the configuration of each hub. The requirements for this view are: Display manageable hub features intuitively Indicate port status of all ports using color Show LED states and interpret port management management card present management card OK management card master Ethernet activity enclosure monitoring/system power supply status loop up enclosure fault uC fault Display type of GBIC or none per port Display Mgmt card if present and identify MAC IP name Display serial # of hub Allow multiple port views to be displayed Display node info per port ALPA list user supplied name user supplied WWN user supplied device type user supplied manufacturer user supplied location 6.6 Port View This view will allow the user to access all manageable features at the port level. The requirements for this view are: port control enable auto insert/bypass if detect fault—loss of signal, loss of lock or transmitter fault (default) OR force loop bypass force external loopback, will force loop bypass OR force insertion on loop port status port control state enable auto insert/bypass force bypass external loopback force insert into loop port module ID copper/fiber(SW,LW) 3 bit GBIC spec id. TABLE 6.6-1 Bits 2:0 Definition 111 No Module Present 110 Copper Module, DB-9 Connector 101 Copper Module, HSSDC Connector 100 Long-wave Laser 011 Serial Interface Protocol 010 Short-wave Laser 001 To Be Defined 000 Gigabit Ethernet port active=signal detected TABLE 6.6-2 Logic Inputs GBIC Mod— TX— Rx— Status Link_Flt Pres Fault signal Green Amber Description F X X OFF OFF Module not inserted T T X OFF ON Faulty Module T F F ON ON Module OK; Missing or Corrupt Data T F T ON OFF Normal Operation port state (loop inserted, bypassed, stuck in PLL) type of port connection, hub/node attached 7. GUI Design The goal of the GUI is to present this functionality in an intuitive and user-friendly package. The primary techniques that will be employed in accomplishing this goal arc: a hierarchical presentation with drill-down capabilities starting with the stack manager at the highest level and drilling down to the individual port level logical topologies using icons that are easily identifiable color coding to indicate health for quick problem detection and isolation gray=unused green=everything is functional yellow=needs attention (should be investigated) red=failure user labeling of all devices readily available “how-to use this window” information a consistent window interface flyover with high-level info on item single click=more detailed info on item double click=drill-down if available a “How to use this window” button a “Text/GUI” display toggle button comprehensive Help system cursor indication of selectable items The major design divisions in the application are as follows: Views Data Objects Data Acquirement Health Determination Management API Mgmt API/SNMP mapping wrappers SNMP Interface Internationalization/Localizability Event Log 7.1 Views There are natural partitions in the information we want to present. The device management is focused on physical devices and the problem detection and isolation is focused on the current state of a loop and the connections to it. In presenting the manageable stacks there is a natural hierarchy: stacks, Mgmt cards, hubs, ports. In presenting information for loop states the hierarchy is: loops, Mgmt cards, hubs, ports. The proposed hierarchical presentation will drill-down as follows: Site view—all manageable stacks and loops Single Stack view Mgmt card view Back of box view Mgmt card view Port detail view Hardware debug view Loop view Mgmt card view Back of box view Mgmt card view Port detail view Hardware debug view The hierarchical presentation will drill-down graphically, as depicted in FIG. 24 by a diagram that is generally indicated by the reference number 480. Magician will display status and control information about each hub in a managed stack or loop by clicking on a hub from the Stack View (see FIG. 11) or Loop view (see FIG. 25) and will provide mechanisms to modify the configuration of each hub. A polling or change mechanism will be required to keep the views in sync with the data. For Apprentice, a simple redraw of objects will be used. It still needs to be determined the extent of change management that should be implemented for Magician. 7.1.3 Loop View Referring to FIG. 25, a Loop View is generally indicated by the reference number 500. The Loop View will be a tree structure type view. It is intended that the user will be able to “build their own loops” by dragging and dropping hubs into a loop root. 7.1.4 Hub View FIG. 26 is similar to previously described FIG. 12, however, FIG. 26 illustrates another Hub View for Stack 2, Hub 1 generally indicated by the reference number 520. FIG. 27 illustrates still another Hub View for Stack 2, Hub 3 generally indicated by the reference number 540. 7.1.5 Mgmt View FIG. 28 illustrates a management view generally indicated by the reference number 560. 7.1.7 Hardware Debug FIG. 29 illustrates a first hardware debug view which is generally indicated by the reference number 580. In this view, a “Ports” tab 582 has been selected. FIG. 30 illustrates hardware debug view 580 with a “Hub” tab 584 selected. FIG. 31 illustrates hardware debug view 580 with a “Loop” tab 586 selected. FIG. 32 illustrates hardware debug view 580 with a “Stack” tab 586 selected. FIG. 33 illustrates hardware debug view 580 with an “Agent” tab 588 selected. It is noted that the “Detect” tab in FIGS. 29-33 has been replaced by a “Sweep” tab having the same functionality. Selection of this sweep tab brings up Hub Sweep View 260 of FIG. 14, described above. 7.2 Data Objects There is also a natural hierarchy of objects in the system we will be handling. The primary objects identified are: lobes: loop nodes, hubs, clouds ports mgmt cards hubs stacks active mgmt cards loops site Referring to FIG. 34, a data object composition chart is generally indicated by the reference number 600. Each object identified has state and control information associated with it. The state information maps into Visual Basic properties and the controls map into Visual Basic methods as follows: Cloud Properties[val Types] ALPAs Graphic Node Properties[val Types] Name WWW Location DeviceType Manufacturer Graphic Lobe Properties[val Types] Length Type [none, unknown, node, hub] ID ConnectObject Port Properties[val Types] ControlState[auto, bypass, extloopback, insert] BeaconState [Boolean] TransmitterState [Boolean] ModuleID [GbEther, TBD, LaserSW, Serial, LaserLW, CopperHSSDC, CopperD9, NoModule] GBICLED [Boolean] FaultLED [On, Off, Blink] State [inserted, bypassed, TxFault] PllLock[True, False] LobeObject Utilization FailoverPort TimesInserted Health DeviceID Graphic Methods(args) Beacon (Boolean) Control (Auto, Bypass, Loopback, Insert) Transmitter (Boolean) FailoverPortSet UpdateInfo GetHealth SetVars(deviceID, vars, vals) RecvVars(deviceID, vars, vals) Class_Initialize Mgmt Properties[val Types] State [active, passive, maintenance, unknown] FailoverPriority[0.7] MAC IP SelftestOK [Boolean] Hard wareVers ion FirmwareVersion LanActivity [Boolean] EventLog Password SyslogHost Name Health DeviceID Graphic Methods(args) FailoverPrioritySet PasswordSet IpSet ForceActive EventFilter SyslogHostSet Reset UpdateInfo GetHealth SetVars(deviceID, vars, vals) RecvVars(deviceID, vars, vals) Class_Initialize Hub Properties[val Types] FanFault [Boolean] TempFault [Boolean] PowerFault [Boolean] uCFault [Boolean] SerialNumber Family HWType NumPorts FWVersion ManagementPresent [Boolean] DiagPort PortsObject MgmtObject LoopObject Health DeviceID Graphic Methods(args) DiagnQsPort Reset(12C, ports) Updatelnfo GetHealth SetVars(deviceID, vars, vals) RecvVars(deviceID, vars, vals) Class_Initialize Loop Properties[val Types] ID State [initializing, open-init, loop up, loop active] ALPAs UpTime TimesReset Utilization HubsObject Health DeviceID Graphic Methods(args) Reset Updatelnfo GetHealth SetVars(deviceID, vars, vals) RecvVars(deviceID, vars, vals) Class_Initialize Stack Properties[val Types] ID HubsObject LoopsObject Health DeviceID Graphic Methods(args) Reset UpdateInfo GetHealth SetVars(deviceID, vars, vals) RecvVars(deviceID, vars, vals) Class_Initialize Site Properties[val Types] EventLog AgentsObject StacksObject Icon Health DeviceID Graphic Methods(args) UpdateInfo GetHealth SetVars(deviceID, vars, vals) RecvVars(deviceID, vars, vals) Class_Initialize 7.3 Data Acquisition A polling mechanism will be employed to obtain current relevant information, which will update the information available for each object. The attributes of the poll mechanism are: Poll Interval 1 min=Default This should be user adjustable. Amount of data acquired: Apprentice only requires a simple “poll all” mechanism, Magician might need a more intelligent poll using the event log as a back-off mechanism due to too high of IP loading for a complete data poll on every poll interval. The back-off mechanism will be further defined when the event log definition is stable. The preliminary algorithm concept is: request active mgmt ID info from all communicating mgmt cards (active or passive) request ALL info from active mgmt cards active mgmt=stack poll event logs from all active mgmt cards if change in event log get pertinent data Another option for minimizing the impact of the poll mechanism is to break requests into chunks instead of requesting all data at once. Type of poll Apprentice will have a blocking poll Magician will have an asynchronous poll provided by the PowerTCP SNMP package The functionality will be implemented by using Timer objects. The ability to refresh object information will be provided consistently and generically by each object having its own UpdateInfo method. 7.4 Health Determination Here is the color coding map to indicate health for problem detection and isolation gray=Unused green=everything is Functional yellow=needs Attention (should be investigated) red=Failure Each of the following objects will have a health indicator that will have an affect on the next level object above it. ports Unused Default Functional GBICLED=on & FaultLED=off Attention ControlState !=auto State=bypassed Failure ModuleID !=NoModule & GBICLED=off TransmitterState=off FaultLED=on ControlState=insert & State !=inserted mgmt (must be present) Unused State=passive Functional State=active & SelftestOK=true & LanActivity=true Attention State=maintenance State !=active & LanActivity=false Failure State=unknown SelftestOK=false State=active & LanActivity=false hubs Unused Never Functional Default Attention mgmt.health=attention 1 ports.health attention Failure mgmt.health=failure 1 port.health=failure FanFault=true TempFault=true PowerFault=true uCFault=true loops Unused Never Functional Attention Failure State !=loopUpiloopActive stacks Unused Never Functional Default Attention hubs.health=attention Failure hubs.health=failure site Unused Never Functional Default Attention hubs.health=attention 1 loops.health=attention Failure hubs.health=failure 1 loops.health=failure This functionality will be consistently and generically implemented by each object having its own GetHealth method. One skilled in the art may devise many alternative configurations for the systems and methods disclosed herein. Therefore, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention and that the present examples and methods are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates generally to the field of digital loop technology utilizing a hub structure and, more particularly, to the field of diagnosis and recovery using a hub in high performance digital loops such as, for example, those hubs seen in Fibre Channel systems. The value of the digital loop in high performance systems such as Fibre Channel is without question. Moreover, the use of such a loop has proven to be enhanced through the use of a hub which serves as a central connection point for the loop. In such a configuration, the loop is said to be in the form of a “star”. Initial development of hubs saw what may be referred to as an unmanaged or “dumb” hub. As these terms indicate, such hubs served much in the manner of a patch panel, devoid of any monitoring capability as to the data passing through the hub. Still considering the hub technology of the prior art, attention is now directed to FIG. 1 which illustrates a more recent digital system generally indicated by the reference numeral 10 . System 10 includes a Fibre Channel hub 12 serving to interconnect a loop 14 including a plurality of stations S 1 -S 4 . System 10 further includes a local area network (LAN) 16 having independent connections 17 a and 17 b with stations S 1 and S 2 , respectively. LAN 16 further includes a station S 5 as well as a work station (WS) 18 . Unlike the earlier generation of hubs described above, hub 12 includes limited diagnostic capabilities. These capabilities have generally been limited to high level observation of the data traveling around the loop. More specifically, these prior art diagnostic capabilities may indicate that certain packets of data are corrupted in addition to indicating the point of origination of the corrupted data. At first blush, this may seem to be extremely useful information for purposes of diagnosis. One must remember, however, that the corrupted data may have traveled through a substantial number of stations between it's point of origin and it's destination. For example, data originating from S 2 and destined for S 1 on the loop must intermediately pass through stations S 3 and S 4 . Therefore, it is possible for the data to have been corrupted at any point along this path. An unsuspecting system administrator who immediately assumes that S 2 is responsible for the corrupted data can waste enormous effort in attempting to diagnose a problem which may occur anywhere along the loop between S 2 and S 1 . Still referring to FIG. 1 , in attempting to perform a detailed diagnosis, a technician may utilize a logic or protocol analyzer 20 . S 2 and hub 12 are originally connected using cable 22 . The analyzer may be connected by disconnecting the original cable 22 at one end and then reconnecting the disconnected end to the analyzer such that original cable 22 is represented as a dashed line indicated by the reference number 22 a and an additional cable 24 is used to connect the analyzer with S 2 . Assuming the problem is not being caused by S 2 , the technician has little hope of resolving the problem using the analyzer as depicted. Thus, the use of an analyzer in such a scenario is disadvantageous. Moreover, as another disadvantage, it is important to note that the use of the analyzer is intrusive. That is, connection of the analyzer itself modifies the structure of the loop. This fact can cause severe complications in some cases. For example, if the problem is being caused by a loose connector (not shown) at S 3 , connection of the analyzer may make the problem disappear if the output signal of the analyzer is greater than the output signal of S 2 whereby to overcome attenuation being caused by the loose connector at S 3 . In this scenario, a reasonable technician may assume that the problem has somehow corrected itself, since the analyzer will indicate that there are no errors. Unfortunately, however, as soon as the original connections are restored, the masked problem will return. The technician is then likely to remain suspicious of S 2 , replacing it and its associated connections and is also likely to suspect fiber 22 . As can be appreciated, this disadvantageous hit or miss technique is likely to be a long process. Moreover, each time a connection is disturbed to insert the analyzer, the loop is taken out of service. The process can also be expensive just due to replacement of any number of perfectly good, but suspect components. Continuing to consider the use of an analyzer, it should also be appreciated that analyzer diagnosis is further complicated by the fact that the analyzer is generally configured to monitor only one or two points. This is an important consideration since the loop, unlike LAN 16 , is not a broadcast medium. That is, the data present between different pairs of stations on loop 14 is itself different since the stations themselves insert and remove data from the loop. Just through the use of an analyzer, it is very difficult to gain a complete “picture” of what is going on in the loop which may, in fact, represent the only way in which a particular problem may be understood. Not only is the analyzer ineffective in many cases, it is also typically expensive. It is not uncommon for a Fibre Channel analyzer to cost $45,000. The present invention provides a highly advantageous arrangement and associated method which resolves the foregoing disadvantages and difficulties while providing still further advantages, as will be seen hereinafter. | <SOH> SUMMARY OF THE INVENTION <EOH>As will be described in more detail hereinafter, there are disclosed herein methods and associated hub arrangements for use in diagnosis and recovery in high performance digital loops such as, for example, those seen in Fibre Channel systems. Accordingly, within a hub configured for interconnection of a plurality of stations as part of a digital system such that digital data flows between the stations based on operational status of the system, an arrangement forms part of the hub which arrangement is connectable at points within the hub and between at least two different pairs of the stations for monitoring certain characteristics of the data in a way which provides for non-invasive identification of one or more conditions related to the operational status of the system. In one aspect of the invention, recovery from a condition which is adverse to the operation of the system is initiated based on identification of the adverse condition. | 20040707 | 20050830 | 20050106 | 83248.0 | 0 | LEVITAN, DMITRY | DIGITAL LOOP DIAGNOSTIC LOOP INITIALIZATION SEQUENCING. | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,886,906 | ACCEPTED | Production or aromatic carotenoids in gram negative bacteria | A method for the in vivo bioconversion of cyclic carotenes having a β-ionone ring to the corresponding aryl carotene is provided. Gram negative host cells expressing a heterologous, codon-optimized gene encoding a carotene desaturase are grown in the presence of a suitable cyclic carotene substrate to effect the production of aromatic carotenoids. | 1. A method for the production of aryl carotenoid compounds comprising: (a) providing a gram negative host cell which comprises a cyclic carotenoid having at least one β-ionone ring; (b) transforming the gram negative host cell of (a) with a foreign gene encoding a carotene desaturase, said gene being codon optimized for expression in the gram negative host cell; and (c) growing the transformed gram negative host cell of (b) under conditions whereby an aryl carotenoid is produced. 2. A method according to claim 1 wherein the aryl carotenoid is asymmetric. 3. A method according to claim 1 wherein the cyclic carotenoid having a β-ionone ring is produced endogenously by the host cell. 4. A method according to claim 1 wherein the cyclic carotenoid having a β-ionone ring is provided exogenously to the host cell. 5. A method according to claim 1 wherein the cyclic carotenoid having a β-ionone ring is selected from the group consisting of β-carotene; γ-carotene; α-carotene; zeaxanthin; β-isorenieratene (φ, β-carotene); torulene; 1′,2′-dihydro-γ-carotene; 7, 8-dihydro-γ-carotene; 7′,8′-dihydro-β-carotene; 7′, 8′, 7, 8-tetrahydro-β-carotene; β-zeacarotene; echinenone; 3-OH-β-carotene; 1′,2′-dihydro-1′-OH-torulene; 16′-OH-torulene; 16′-oxo-torulene; and 16′-carboxy-torulene. 6. A method according to claim 1 wherein the aryl carotenoid is selected from the group consisting of: isorenieratene (φ, φ-carotene); chlorobactene (φ, ψ-carotene); β-isorenieratene (φ, β-carotene); didehydro-φ, β-carotene; φ,ε-carotene; 1,2-didehydrochlorobactene; 1′, 2′-dihydrochlorobactene; 7, 8-dihydro-chlorobactene; 7′8′-dihydro-isorenieratene; 7′, 8′, 7, 8-tetrahydro-isorenieratene; 7′ 8′-dihydro-chlorobactene; β, φ-carotene4-one; β, φ carotene-3-ol; 3-OH-isorenieratene; 3, 3′-dihydroxy-isorenieratene; 7′, 8′-didehydrorenieratene; OH-chlorobactene; 1′,2′-dihydro-1′-OH-didehydrochlorobactene; 16′-OH-didehydrochlorobactene; 16′-oxo-didehydrochlorobactene; and 16′-carboxy-didehydrochlorobactene. 7. A method according to claim 1 wherein the codon optimized gene encoding a carotene desaturase is a crtU gene having the nucleic acid sequence selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53, and wherein the gram negative host is E. coli. 8. A method according to claim 1 wherein the gram negative host cell is a member of a bacterial family selected from the group consisting of Bacteroidaceae, Enterobacteriaceae, Vibrionaceae, Pasteurellae, Pseudomonadaceae and Neisseriaceae. 9. A method according to claim 8 wherein the gram negative host cell is a member of a bacterial genus selected from the group consisting of: Bacteroides, Fusobacterium Escherichia, Klebsiella, Proteus, Enterobacter, Serratia, Salmonella, Shigella, Citrobacter, Morganella, Yersinia, Erwinia, Vibrio, Aeromonas, Pasteurella, Haemophilus, Actinobacillus, Pseudomonas, Brucella, Flavobacterium, Alcaligenes, Acetobacter, Achromobacter, Acinetobacter, and Moraxella. 10. A method of regulating aryl carotenoid biosynthesis in E. coli organism comprising: (a) introducing into an E. coli a carotene desaturase gene having the nucleic acid sequence selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53; and (b) growing the E. coli of (a) under conditions whereby the. carotene desaturase gene is expressed and aryl carotenoid biosynthesis is regulated. 11. A method according to claim 10 wherein the carotene desaturase gene is upregulated. 12. A method according to claim 10 wherein said carotene desaturase gene is over-expressed on a multicopy plasmid. 13. A method according to claim 10 wherein said carotene desaturase gene is operably linked to an inducible or regulated promoter. 14. A method according to claim 13 wherein the carotene desaturase gene is down-regulated. 15. A method according to claim 14 wherein said carotene desaturase gene is expressed in antisense orientation. 16. A method according to claim 14 wherein said carotene desaturase gene is disrupted by insertion of foreign DNA into the coding region. 17. A method for the production of isorenieratene comprising: (a) providing a gram negative host cell which comprises β-carotene; (b) transforming the gram negative host cell of (a) with a gene encoding a carotene desaturase, said gene being codon optimized for expression in said gram negative host; and (c) growing the transformed gram negative host cell of (b) under conditions whereby isorenieratene is produced. 18. A method for the production of chlorobactene comprising: (a) providing a gram negative host cell which comprises γ-carotene; (b) transforming the gram negative host cell of (a) with a gene encoding a carotene desaturase, said gene being codon optimized for expression in said gram negative host; and (c) growing the gram negative transformed host cell of (b) under conditions whereby chlorobactene is produced. 19. A method according to either of claims 17 or 18 wherein the gram negative host cell is a member of a bacterial family selected from the group consisting of Bacteroidaceae, Enterobacteriaceae, Vibrionaceae, Pasteurellae, Pseudomonadaceae and Neisseriaceae. 20. A method according to claim 19 wherein the gram negative host cell is a member of a bacterial genus selected from the group consisting of: Bacteroides, Fusobacterium Escherichia, Klebsiella, Proteus, Enterobacter, Serratia, Salmonella, Shigella, Citrobacter, Morganella, Yersinia, Erwinia, Vibrio, Aeromonas, Pasteurella, Haemophilus, Actinobacillus, Pseudomonas, Brucella, Flavobacterium, Alcaligenes, Acetobacter, Achromobacter, Acinetobacter, and Moraxella. 21. A method according to claim 17 wherein the β-carotene is produced endogenously by the host cell. 22. A method according to claim 17 wherein the β-carotene is provided exogenously to the host cell. 23. A method according to claim 18 wherein the γ-carotene is produced endogenously by the host cell. 24. A method according to claim 18 wherein the γ-carotene is provided exogenously to the host cell. 25. A method according to either of claims 17 or 18 wherein the gram negative host cell is E. coli and the carotene desaturase gene has a nucleic acid sequence selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53. 26. An E. coli codon optimized carotene desaturase gene selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53. | This application claims the benefit of U.S. Provisional Application No. 60/486,106 filed Jul. 10, 2003. FIELD OF THE INVENTION This invention is in the field of microbiology. More specifically, this invention pertains to nucleic acid fragments encoding enzymes useful for production of aromatic carotenoid compounds. BACKGROUND OF THE INVENTION Carotenoids are pigments that are ubiquitous throughout nature and synthesized by all photosynthetic organisms, and in some heterotrophic growing bacteria and fungi. Carotenoids provide color for flowers, vegetables, insects, fish, and birds. Colors range from yellow to red with variations of brown and purple. As precursors of vitamin A, carotenoids are fundamental components in our diet and they play an important role in human health. Industrial uses of carotenoids include pharmaceuticals, food supplements, animal feed additives, and colorants in cosmetics, to mention a few. Because animals are unable to synthesize carotenoids de novo, they must obtain them by dietary means. Thus, manipulation of carotenoid production and composition in bacteria can provide new or improved sources for carotenoids. Carotenoids come in many different forms and chemical structures. Most naturally occurring carotenoids are hydrophobic tetraterpenoids containing a C40 methyl-branched hydrocarbon backbone derived from successive condensation of eight C5 isoprene units (IPP). In addition, novel carotenoids with longer or shorter backbones occur in some species of nonphotosynthetic bacteria. Carotenoids may be acyclic, monocyclic, or bicyclic depending on whether the ends of the hydrocarbon backbones have been cyclized to yield aliphatic or cyclic ring structures (G. Armstrong, (1999) In Comprehensive Natural Products Chemistry, Elsevier Press, volume 2, pp 321-352). Carotenoid biosynthesis starts with the isoprenoid pathway to generate the C5 isoprene unit, isopentenyl pyrophosphate (IPP). IPP is then condensed with its isomer dimethylallyl pyrophosphate (DMAPP) to generate the C10 geranyl pyrophosphate (GPP) which is then elongated to form the C15 farnesyl pyrophosphate (FPP). FPP synthesis is common in both carotenogenic and non-carotenogenic bacteria. Additional enzymes in the carotenoid pathway are able to then generate carotenoid pigments from the FPP precursor, segregating into two categories: (i) carotene backbone synthesis enzymes and (ii) subsequent modification enzymes. The backbone synthesis enzymes include geranyl geranyl pyrophosphate synthase, phytoene synthase, phytoene dehydrogenase and lycopene cyclase, etc. The modification enzymes include ketolases, hydroxylases, dehydratases, glycosylases, etc. It is known that β-carotene can be converted to isorenieratene, an aromatic carotenoid, by a CrtU carotene desaturase. The crtU gene, encoding the carotene desaturase, has been identified in a few actinomycetes including Streptomyces, Mycobacterium and Brevibacterium (Krugel et al., Biochimica et Biophysica Acta, 1439: 57-64 (1999); Krubasik and Sandmann, Mol Gen Genet 263: 423432 (2000); and Viveiros et al., FEMS Microbiol Lett, 187: 95-101 (2000)). Another aryl-carotene, chlorobactene, was reported in photosynthetic green bacteria (Liaaen-Jensen et al., Acta Chem. Scand 18: 1703-1718 (1964); Takaichi et al., Arch Microbiol, 168: 270-276 (1997)). Recent genomic sequencing of Chlorobium tepidum identified a putative carotene desaturase gene (Eisen et al., PNAS USA, 99: 9509-9514 (2002), which might be responsible for the synthesis of the native chlorobactene and derivatives. However, function of the putative carotene desaturase gene from Chlorobium has not yet been determined. It is likely that the CrtU from actinomycetes might also act on other substrates in addition to β-carotene to produce a variety of aryl-carotenoids, such as converting γ-carotene to chlorobactene. Schumann et al. (Mol Gen Genet, 252: 658-666 (1996)) reported difficulty in attempting to express crtU in heterologous hosts. However, Lee et al. (Chem Biol 10(5): 453-462 (2003)) recently reported successful expression of the Brevibacterium linens crtU (DSMZ 20426) in E. coli using a pUC-derived expression vector. Lee et al. were able to detect the production of isorenieratene (in cells engineered to produce β-carotene) and didehydro-β-θ-carotene (in cells engineered to produce torulene). Lee et al. did not report the levels of aromatic carotenoids produced. It is likely the level was low since a low copy number pACYC-base plasmid was used to produce β-carotene precursor in a non-engineered E. coli host. Production of commercially-significant amounts of aryl carotenoids has not been reported in the literature. Expressing genes from gram positive bacteria (with high G+C content) in E. coli is known to be often difficult. Low yields of protein in heterologous expression systems can been attributed to differences in codon usage. Difficulties in expressing heterologous genes in a host strain are generally due to an extremely rare codon used by host strain and correlates with low levels of its corresponding tRNA. The inability to adequately express CrtU carotene desaturases in a gram-negative host for production of aryl carotenoids at commercially-useful levels presents a significant hurdle to the synthesis of a variety of aryl-carotenoids by genetic engineering. Furthermore, natural aryl-carotenoids are always present as mixtures of the aryl-carotenoid with their precursors or derivatives (Kohl et al., Phytochemistiy, 22: 207-213 (1983); Takaichi et al., supra). Production of a pure aryl-carotenoid requires the ability to efficiently express the carotene desaturase in an industrially-useful heterologous host, such as E. coli. The problem to be solved is to express a functional carotene desaturase (crtU) gene for the production of aryl-carotenoids in a gram-negative production host at commercially-significant concentrations. Applicants have solved the stated problem by isolating the crtU gene from Brevibacterium linens and expressing an optimized version of this gene in an Escherichia coli strain engineered to produce high levels of carotenoids. SUMMARY OF THE INVENTION The present invention provides methods for the expression of carotene desaturase genes and proteins in gram negative host cells for the conversion of cyclic carotenoids to the corresponding aryl compound. Accordingly the invention provides a method for the production of aryl carotenoid compounds comprising: (a) providing a gram negative host cell which comprises a cyclic carotenoid having at least one u-ionone ring; (b) transforming the gram negative host cell of (a) with a foreign gene encoding a carotene desaturase, said gene being codon optimized for expression in the gram negative host cell; and (c) growing the transformed gram negative host cell of (b) under conditions whereby an aryl carotenoid is produced. In similar fashion the invention provides a method of regulating aryl carotenoid biosynthesis in an E. coli host comprising: (a) introducing into an E. coli a carotene desaturase gene having the nucleic acid sequence selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53; and (b) growing the E. coli of (a) under conditions whereby the carotene desaturase gene is expressed and aryl carotenoid biosynthesis is regulated. In a preferred embodiment the invention provides a method for the production of isorenieratene comprising: (a) providing a gram negative host cell which comprises β-carotene; (b) transforming the gram negative host cell of (a) with a gene encoding a carotene desaturase, said gene being codon optimized for expression in said gram negative host; and (c) growing the transformed gram negative host cell of (b) under conditions whereby an aryl carotenoid is produced. In an alternate embodiment the invention provides a method for the production of chlorobactene comprising: (a) providing a gram negative host cell which comprises γ-carotene; (b) transforming the gram negative host cell of (a) with a gene encoding a carotene desaturase, said gene being codon optimized for expression in said gram negative host; and (c) growing the gram negative transformed host cell of (b) under conditions whereby chlorobactene is produced. In an alternate embodiment the invention provides an E. coli codon optimized carotene desaturase gene selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53. BRIEF DESCRIPTION OF THE DRAWINGS AND SEQUENCE DESCRIPTIONS FIG. 1 shows the enzymatic aromatization of carotenoids by CrtU. FIG. 2 shows the isoprenoid pathway in E. coli. FIG. 3 shows the strategy for chromosomal promoter replacement of isoprenoid genes using two PCR fragments integration method in E. coli. FIG. 4 shows the strategy used for construction of the kan-PT6-crtEIB construct. FIG. 5 shows plasmid pSUH5, used for the preparation of the PCR DNA fragment having a fused antibiotic selection marker and phage T5 promoter (kan-PT5). FIG. 6 diagrams the upper and lower carotenoid pathway. The invention can be more fully understood from the following detailed description, biological deposits, and the accompanying sequence descriptions, which for a part of this application. The following sequences comply with 37 C.F.R. 1.821-1.825 (“Requirements for Patent Applications Containing Nucleotide Sequences and/or Amino Acid Sequence Disclosures—the Sequence Rules”) and are consistent with World Intellectual Property Organization (WIPO) Standard ST.25 (1998) and the sequence listing requirements of the EPO and PCT (Rules 5.2 and 49.5(a-bis), and Section 208 and Annex C of the Administrative Instructions). The symbols and format used for nucleotide and amino acid sequence data comply with the rules set forth in 37 C.F.R. §1.822. Gene/Protein Nucleotide Amino Acid Product Source SEQ ID NO SEQ ID NO CrtE Pantoea stewartii 1 2 CrtX Pantoea stewartii 3 4 CrtY Pantoea stewartii 5 6 CrtI Pantoea stewartii 7 8 CrtB Pantoea stewartii 9 10 CrtZ Pantoea stewartii 11 12 SEQ ID NOs:13-14 are oligonucleotide primers used to amplify the carotenoid biosynthetic gene cluster from Pantoea stewartii. SEQ ID NO:15 is the nucleotide sequence of crtU gene (GenBank® Accession number AF139916) from Brevibacterium linens ATCC 9175. SEQ ID NOs:16-17 are oligonucleotide primers used to amplify the optimized crtU product from B. linens. SEQ ID NO:18 is the predicted nucleotide sequence of the codon optimized crtU gene, created for expression in E. coli. SEQ ID NO:19 is the deduced amino acid sequence of SEQ ID NO:18. SEQ ID NOs:20-27 are oligonucleotide primers used to create chromosomal integrations of a strong promoter upstream from isoprenoid genes in E. coli. SEQ ID NOs:28-32 are oligonucleotide primers used to confirm integration of the T5 promoter in the E. coli chromosome. SEQ ID NOs:33-36 are oligonucleotide primers used to amplify crtE for chromosomal integration. SEQ ID NOs:37-38 are oligonucleotide primers used to confirm chromosomal integration of crtE. SEQ ID NOs:39-41 are oligonucleotide primers used to amplify crtIB for chromosomal integration. SEQ ID NOs:42-45 are oligonucleotide primers used to confirm chromosomal integration of crtIB. SEQ ID NOs:46-48 are oligonucleotide primers used to confirm 16 s identity of Rhodococcus AN12. SEQ ID NO:49 is the nucleotide sequence for the crtL lycopene cyclase of Rhodococcus AN12. SEQ ID NO:50 is the deduced amino acid sequence of SEQ ID NO:49. SEQ ID NOs:51-52 are oligonucleotide primers used to amplify crtL of Rhodococcus AN12. SEQ ID NO:53 is the nucleotide sequence for codon optimized crtU gene for expression in E. coli as amplified by PCR. SEQ ID NO:54 is the nucleotide sequence for plasmid pPCB15. SEQ ID NO:55 is the nucleotide sequence for plasmid pKD46. SEQ ID NO:56 is the nucleotide sequence for plasmid pSUH5. SEQ ID NO:57 is the nucleotide sequence for the PT5 promoter. BRIEF DESCRIPTION OF BIOLOGICAL DEPOSITS Applicants have made the following biological deposits under the terms of the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the purposes of Patent Procedure: Depositor Int'l. Identification Depository Date of Reference Designation Deposit Plasmid pCP20 ATCC# Jun. 13, 2002 PTA-4455 E. coli strain DPR676: ATCC# Apr. 11, 2003 MG1655 PT5-dxs, PT5- PTA-5136 idi pTrcHis2-TOPO-crtU (ampR), pBHR-crt+ (kanR) As used herein, “ATCC” refers to the American Type Culture Collection International Depository Authority located at ATCC, 10801 University Blvd., Manassas, Va. 20110-2209, USA. The “International Depository Designation” is the accession number to the culture on deposit with ATCC. The listed deposits will be maintained in the indicated international depository for at least thirty (30) years and will be made available to the public upon the grant of a patent disclosing it. The availability of a deposit does not constitute a license to practice the subject invention in derogation of patent rights granted by government action. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for the conversion of cyclic carotenoids having a β-ionone ring to the corresponding aryl carotenoid, via the heterologous expression of a codon optimized carotene desaturase gene (crtU), in gram negative bacteria. The expression of crtU in a heterologous host is useful for the selective production of aryl carotenoids, as well as for the regulation and production of other carotenoids in the isoprenoid biosynthetic pathway. There is a general practical utility for microbial isoprenoid production since carotenoid compounds are very difficult to make chemically (Nelis and Leenheer, Appl. Bactediol., 70:181-191 (1991)). Introduction of the aromatic ring(s) by expression of crtU will likely render the carotenoids more stable, which is desired for certain applications such as food colorants. For example, aromatic carotenoids, in particular dihydroxyisorenieratene, are used in dairy applications for coloring various cheeses and yellow carotenoids are particularly useful for the poultry industry, resulting in a deep yellow color to egg yolks and the skins chickens. In this disclosure, a number of terms and abbreviations are used for the interpretation of the Claims and the specification. “Open reading frame” is abbreviated ORF. “Polymerase chain reaction” is abbreviated PCR. “Isopropyl-beta-D-thiogalactoside” is abbreviated IPTG. Within the present disclosure, names of genes will be in italics whereas the corresponding encoded protein will be in standard font. For example the genes crtU, crtE, crtY, crtI, crtB, crtZ, dxs, idi, ispD(ygbP),and ispF(ygbB) will encode polypeptides named CrtU, CrtE, CrtY, CrtI, CrtB, CrtZ, Dxs, Idi, IspD(YgbP), and IspF(YgbB), respectively. As used herein, an “isolated nucleic acid fragment” is a polymer of RNA or DNA that is single- or double-stranded, optionally containing synthetic, non-natural or altered nucleotide bases. An isolated nucleic acid fragment in the form of a polymer of DNA may be comprised of one or more segments of cDNA, genomic DNA or synthetic DNA. The term “isoprenoid” or “terpenoid” refers to the compounds are any molecule derived from the isoprenoid pathway including 10 carbon terpenoids and their derivatives, such as carotenoids and xanthophylls. The term “carotenoid” refers to a class of hydrocarbons having a conjugated polyene carbon skeleton formally derived from isoprene. This class of molecules is composed of C30 diapocarotenoids and C40 carotenoids and their oxygenated derivatives; and, these molecules typically have strong light absorbing properties. Carotenoids can be acyclic or terminated with one (monocyclic) or two (bicyclic) cyclic end groups. The term “carotenoid” may include both carotenes and xanthophylls. A “carotene” refers to a hydrocarbon carotenoid. Carotene derivatives that contain one or more oxygen atoms, in the form of hydroxy-, methoxy-, oxo-, epoxy-, carboxy-, or aldehydic functional groups, or within glycosides, glycoside esters, or sulfates, are collectively known as “xanthophylls”. Carotenoids that are particularly suitable in the present invention are monocyclic and bicyclic carotenoids having at least one β-ionone ring capable of desaturation to form an aryl carotenoid. Suitable carotenoids typically include C30 and C40 carotenoids; however any carotenoid having a β-ionone ring capable of being desaturated would be suitable in the present invention. “Asymmetric carotenoids” refers to monocyclic carotenoids. Examples of asymmetric carotenoids include γ,ψ-carotene, ε,ψ-carotene, β,ψ-carotene, or φ, ψ-carotene (chlorobactene) as well as retinal, retinol, 14′-apo-β-caroten-14′, 12′, 10′, 8′, 6′, 4′, or 2′-al or -ol. Torulene, torularhodinaldehyde, torularhodin, torularhodinol, and torularhodin methyl ester are also examples. “C30 diapocarotenoids” consist of six isoprenoid units joined in such a manner that the arrangement of isoprenoid units is reversed at the center of the molecule so that the two central methyl groups are in a 1,6-positional relationship and the remaining nonterminal methyl groups are in a 1,5-positional relationship. All C30 carotenoids may be formally derived from the acyclic C30H42 structure (hereinafter referred to as “diapophytoene”), having a long central chain of conjugated double bonds, by: (i) hydrogenation (ii) dehydrogenation, (iii) cyclization, (iv) oxidation, (v) esterification/ glycosylation, or any combination of these processes. “Tetraterpenes” or “C40 carotenoids” consist of eight isoprenoid units joined in such a manner that the arrangement of isoprenoid units is reversed at the center of the molecule so that the two central methyl groups are in a 1,6-positional relationship and the remaining nonterminal methyl groups are in a 1,5-positional relationship. All C40 carotenoids may be formally derived from the acyclic C40H56 structure. Non-limiting examples of C40 carotenoids include: phytoene, lycopene, β-carotene, zeaxanthin, astaxanthin, and canthaxanthin. The term “carotenoid biosynthetic pathway” refers to those genes comprising members of the upper isoprenoid pathway and/or lower carotenoid biosynthetic pathway. The terms “upper isoprenoid pathway” and “upper pathway” are used interchangeably and refer to enzymes involved in converting pyruvate and glyceraldehyde-3-phosphate to farnesyl pyrophosphate (FPP). Genes encoding these enzymes include, but are not limited to: the “dxs” gene (encoding 1-deoxyxylulose-5-phosphate synthasey; the “ispC” gene (encoding 1-deoxyxylulose-5-phosphate reductoisomerase; also known as dxr); the “ispD” gene (encoding a 2C-methyl-D-erythritol cytidyltransferase enzyme; also known as ygbp); the “ispE” gene (encoding 4-diphosphocytidyl-2-C-methylerythritol kinase; also known as ychB); the “ispF” gene (encoding a 2C-methyl-D-erythritol 2,4-cyclodiphosphate synthase; also known as ygbB); the “pyrG” gene (encoding a CTPsynthase); the ispG” gene (encoding a enzyme that is involved in conversion of 2C-methyl-D-erythritol-2,4-cyclodiphosphate to 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate; also known as gcpE); the “ispH” gene (encoding a enzyme that is involved in is involved in conversion of 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP); also known as lytB); the “idi” gene (responsible for the intramolecular conversion of IPP to dimethylallyl pyrophosphate); and the “ispA” gene (encoding geranyltransferase or farnesyl diphosphate synthase) in the isoprenoid pathway. The terms “lower carotenoid biosynthetic pathway” and “lower pathway” will be used interchangeably and refer to those enzymes which convert FPP to a suite of carotenoids. These include those genes and gene products that are involved in the immediate synthesis of either diapophytoene (whose synthesis represents the first step unique to biosynthesis of C30 carotenoids) or phytoene (whose synthesis represents the first step unique to biosynthesis of C40 carotenoids). All subsequent reactions leading to the production of various C30-C40 carotenoids are included within the lower carotenoid biosynthetic pathway. These genes and gene products comprise all of the “crf” genes including, but not limited to: crtM, crtN, crtN2, crtE, crtX, crtY, crtI, crtB, crtZ, crtW, crtO, crtA, crtC, crtD, crtF, and crtU. Finally, the term “lower carotenoid biosynthetic enzyme” is an inclusive term referring to any and all of the enzymes in the present lower pathway including, but not limited to: CrtM, CrtN, CrtN2, CrtE, CrtX, CrtY, CrtI, CrtB, CrtZ, CrtW, CrtO, CrtA, CrtC, CrtD, CrtF, and CrtU. The term “cyclic carotenoid” refers to a carotenoid having at least one β-ionone ring. The terms “β-ionone ring” and “β-ionone group” are defined as the C9H15 shown as the boxed cyclic structure in γ-carotene or β-carotene (FIG. 1). The term “aromatic carotenoid” or “aryl carotenoid” refers to C30 and C40 carotenoids with at least one aromatic end group, including but not limited to, isorenieratene, β-isorenieratene, chlorobactene, and derivatives thereof as shown in FIG. 1. The term “lycopene cyclase” or “β-cyclase” are used interchangeably and refer to an enzyme that catalyzes the formation of a β-ionone ring cyclic end group from the acyclic ψ-end group. Lycopene cyclases normally form the bicyclic carotenoid (i.e. β-carotene) from substrates having two ψ-end groups (i.e. lycopene). Lycopene cyclases have been reported that selectively convert only one of two ψ-end groups, forming monocyclic carotenoids (U.S. Ser. No. 10/292577) such as γ-carotene. The term “Pantoea stewartii” is abbreviated as “P. stewartii” and is used interchangeably with Erwinia stewartii (Mergaert et al., Int. J. Syst. Bacteriol., 43:162-173 (1993)), and refers to ATCC strain number 8199. The term “Brevibacterium linens” is abbreviated “B. linens” and refers to ATCC strain number 9175. The terms “Rhodococcus erythropolis AN12” or “AN12” will be used interchangeably and refer to the Rhodococcus erythropolis AN12 strain. The term “dxs” refers to the enzyme D-1-deoxyxylulose 5-phosphate encoded by the E.coli dxs gene that catalyzes the condensation of pyruvate and D-glyceraldehyde 3-phosphate to D-1-deoxyxylulose 5-phosphate (DOXP). The term “idi” refers to the enzyme isopentenyl diphosphate isomerase encoded by the E.coli idi gene that converts isopentenyl diphosphate to dimethylallyl diphosphate. The term “YgbP” or “IspD” and refers to the enzyme encoded by the ygbB or ispD gene that catalyzes the CTP-dependent cytidylation of 2-C-methyl-D-erythritol-4-phosphate to 4-diphosphocytidyl-2C-methyl-D-erythritol. The names of the gene, ygbP or ispD, are used interchangeably in this application. The names of gene product, YgbP or IspD are used interchangeably in this application. The term “YgbB” or “IspF” refers to the enzyme encoded by the ybgB or ispF gene that catalyzes the cyclization with loss of CMP of 4-diphosphocytidyl-2C-methyl-D-erythritol to 4-diphosphocytidyl-2C-methyl-D-erythritol-2-phosphate to 2C-methyl-D-erythritol-2,4-cyclodiphosphate. The names of the gene, ygbB or ispF, are used interchangeably in this application. The names of gene product, YgbB or IspF are used interchangeably in this application. The term “ygbBP” refers to the two genes ygbB and ygbP. The term “CrtE” refers to geranylgeranyl pyrophosphate synthase enzyme encoded by crtE gene represented in SEQ ID NO:1, which converts trans-trans-farnesyl diphosphate+isopentenyl diphosphate to pyrophosphate+geranylgeranyl diphosphate The term “CrtY” refers to lycopene cyclase enzyme encoded by crtY gene represented in SEQ ID NO:5, which converts lycopene to beta-carotene. The term “Crtl” refers to phytoene dehydrogenase enzyme encoded by crtl gene represented in SEQ ID NO:7, which converts phytoene into lycopene via the intermediaries of phytofluene, zeta-carotene, and neurosporene by the introduction of 4 double bonds The term “CrtB” refers to phytoene synthase enzyme encoded by crtB gene represented in SEQ ID NO:9, which catalyses reaction from prephytoene diphosphate to phytoene. The term “carotene desaturase” refers to the group of enzymes that can desaturate and- transfer methyl or other groups of the β-ionone ring of mono- or bi-cyclic carotenoids. The term “CrtU” refers to a carotene desaturase which can convert a carotenoid comprised of at least one β-ionone ring to an aryl carotenoid. In the present invention, a codon optimized crtU gene was expressed in a heterologous host, converting β-carotene or γ-carotene to the aryl-carotenes isorenieratene and chlorobactene, respectively. The term “CrtZ” refers to a β-carotene hydroxylase enzyme encoded by crtZ gene represented in SEQ ID NO:11, which catalyses hydroxylation reaction from β-carotene to zeaxanthin. The CrtZ gene product also has the ability to convert canthaxanthin to astaxanthin. The term “pKD46” refers to the plasmid constructed by Datsenko and Wanner (PNAS, 97:6640-6645 (2000); SEQ ID NO:55). The term “pSUH5” refers to the plasmid that was constructed in this invention by cloning a phage T5 promoter (PT5) region into the Ndel restriction endonuclease site of pKD4 (Datsenko and Wanner, supra). pSUH5 was used as a template plasmid for PCR amplification of a fused kanamycin selectable marker/phage T5 promoter linear DNA fragment (FIG. 5; SEQ ID NO:56). The terms “PT5 promoter” and “T5 promoter” refer to the nucleotide sequence that comprises the −10 and −35 consensus sequences, lactose operator (lacO), and ribosomal binding site (rbs) from phage T5 (SEQ ID NO:57). The term “helper plasmid” refers to either pKD46 encoding λ-Red recombinase or pCP20 (ATCC PTA-4455) encoding FLP site specific recombinase (Datsenko and Wanner, supra). The terms “λ-Red recombinase system”, “λ-Red system”, and “λ-Red recombinase” are used interchangeably and refer to three essential genes, exo, bet, and gam, that are contained on a helper plasmid, pKD46 (Datsenko and Wanner, supra). The term “homology arm” refers to a nucleotide sequence which enables homologous recombination between two nucleic acids having substantially the same nucleotide sequence in a particular region of two different nucleic acids. The preferred size range of the nucleotide sequence of the homology arm is from about 10 to about 50 nucleotides. The term “triple homologous recombination” in the present invention refers to a genetic recombination between two linear DNA nucleotides and the target chromosome via their homologous sequences resulting in chromosomal integration of two linear nucleotides into the target of chromosome. The term “site-specific recombinase” is used in the present invention to describe a system comprised of one or more enzymes which recognize specific nucleotide sequences (recombination target sites) and which catalyze recombination between the recombination target sites. Site-specific recombination provides a method to rearrange, delete, or introduce exogenous DNA. Examples of site-specific recombinases and their associated recombination target sites are flippase (FLP/FRT), Cre-lox, R/RS, Gin/gix, Xer/dif, and InVatt. In the present invention the Applicants illustrate the use of a site-specific recombinase to remove selectable markers. Antibiotic resistance markers, flanked on both sides by FRT recombination target sites, are removed by expression of the FLP site-specific recombinase. This method is used so that the number of chromosomal modifications necessary for microbial pathway engineering is not limited to the number of available selection markers (Huang et al., J. Bacteriol., 179(19): 6076-6083 (1997)). The terms “transduction” and “general transduction” are used interchangeably and refer to a phenomenon in which bacterial DNA is transferred from one bacterial cell (the donor) to another (the recipient) by a phage particle containing bacterial DNA. The terms “P1 donor cell” and “donor cell” are used interchangeably in the present invention and refer to a bacterial strain susceptible to infection by a bacteriophage or virus, and which serves as a source for the nucleic acid fragments packaged into the transducing particles. Typically, the genetic make up of the donor cell is similar or identical to the “recipient cell” which serves to receive P1 lysate containing transducing phage or virus produced by the donor cell. The terms “P1 recipient cell” and “recipient cell” are used interchangeably in the present invention and refer to a bacterial strain susceptible to infection by a bacteriophage or virus and which serves to receive lysate containing transducing phage or virus produced by the donor cell. The terms “stacking”, “combinatorial stacking”, “chromosomal stacking”, and “trait stacking” are used interchangeably and refer to the repeated process of stacking multiple genetic traits into one E. coli host using the bacteriophage P1 in combination with the site-specific-recombinase system for removal of selection markers. The terms “parallel combinatorial fashion” and “combinatorial fashion” are used interchangeably and refer to the P1 transduction with the P1 lysate mixture made from various donor cells, so that multiple genetic traits can move the recipient cell in parallel. The terms “integration cassette” and “recombination element” refer to a linear nucleic acid construct useful for the transformation of a recombination proficient bacterial host. Recombination elements of the invention may include a variety of genetic elements such as selectable markers, functional DNA fragments, and recombination regions having homology to regions on a bacterial chromosome or other recombination elements. Functional DNA fragments can include promoters, coding sequences, genes, and other regulatory elements specifically engineered into the recombination element to impart a desired phenotypic change upon recombination. “Operon”, in bacterial DNA, is a cluster of contiguous genes transcribed from one promoter that gives rise to a polycistronic mRNA. The term “percent identity”, as known in the art, is a relationship between two or more polypeptide sequences or two or more polynucleotide sequences, as determined by comparing the sequences. In the art, “identity” also means the degree of sequence relatedness between polypeptide or polynucleotide sequences, as the case may be, as determined by the match between strings of such sequences. “Identity” and “similarity” can be readily calculated by known methods, including but not limited to those described in: Computational Molecular Biology (Lesk, A. M., ed.) Oxford University Press, NY (1988); Biocomputing: Informatics and Genome Projects (Smith, D. W., ed.) Academic Press, NY (1993); Computer Analysis of Sequence Data. Part I (Griffin, A. M., and Griffin, H. G., eds.) Humana Press, NJ (1994); Sequence Analysis in Molecular Biology (von Heinje, G., ed.) Academic Press (1987); and Sequence Analysis Primer (Gribskov, M. and Devereux, J., eds.) Stockton Press, NY (1991). Preferred methods to determine identity are designed to give the best match between the sequences tested. Methods to determine identity and similarity are codified in publicly available computer programs. Sequence alignments and percent identity calculations may be performed using the Megalign program of the LASERGENE bioinformatics computing suite (DNASTAR Inc., Madison, Wis.). Multiple sequence alignment can be performed using the Clustal method of alignment (Higgins and Sharp, CABIOS. 5:151-153 (1989)) with the default parameters (GAP PENALTY=10, GAP LENGTH PENALTY=10). Default parameters for pairwise alignments using the Clustal method are typically KTUPLE 1, GAP PENALTY=3, WINDOW=5, and DIAGONALS SAVED=5. “Synthetic genes” can be assembled from oligonucleotide building blocks that are chemically synthesized using procedures known to those skilled in the art. These building blocks are ligated and annealed to form gene segments that are then enzymatically assembled to construct the entire gene. “Chemically synthesized”, as related to a sequence of DNA, means that the component nucleotides were assembled in vitro. Manual chemical synthesis of DNA may be accomplished using well-established procedures, or automated chemical synthesis can be performed using one of a number of commercially available machines. Accordingly, the genes can be tailored for optimal gene expression based on optimization of nucleotide sequence to reflect the codon bias of the host cell. The skilled artisan appreciates the likelihood of successful gene expression if codon usage is biased towards those codons favored by the host. Determination of preferred codons can be based on a survey of genes derived from the host cell where sequence information is available. “Gene” refers to a nucleic acid fragment that expresses a specific protein, including regulatory sequences preceding (5′ non-coding sequences) and following (3′ non-coding sequences) the coding sequence. “Native gene” refers to a gene as found in nature with its own regulatory sequences. “Chimeric gene” refers to any gene that is not a native gene, comprising regulatory and coding sequences that are not found together in nature. Accordingly, a chimeric gene may comprise regulatory sequences and coding sequences that are derived from different sources, or regulatory sequences and coding sequences derived from the same source, but arranged in a manner different than that found in nature. “Endogenous gene” refers to a native gene in its natural location in the genome of an organism. A “foreign” gene refers to a gene not normally found in the host organism, but that is introduced into the host organism by gene transfer. Foreign genes can comprise native genes inserted into a non-native organism, or chimeric genes. A “transgene” is a gene that has been introduced into the genome by a transformation procedure. “Coding sequence” refers to a DNA sequence that codes for a specific amino acid sequence. “Suitable regulatory sequences” refer to nucleotide sequences located upstream (5′ non-coding sequences), within, or downstream (3′ non-coding sequences) of a coding sequence, and which influence the transcription, RNA processing or stability, or translation of the associated coding sequence. Regulatory sequences may include promoters, translation leader sequences, introns, polyadenylation recognition sequences, RNA processing sites, effector binding sites, and stem-loop structures. “Promoter” refers to a DNA sequence capable of controlling the expression of a coding sequence or functional RNA. In general, a coding sequence is located 3′ to a promoter sequence. Promoters may be derived in their entirety from a native gene, or be composed of different elements derived from different promoters found in nature, or even comprise synthetic DNA segments. It is understood by those skilled in the art that different promoters may direct the expression of a gene in different tissues or cell types, or at different stages of development, or in response to different environmental or physiological conditions. Promoters that cause a gene to be expressed in most cell types at most times are commonly referred to as “constitutive promoters”. “Inducible promoters” are promoters that are not always active the way constitutive promoters are (e.g. viral promoters). Some inducible promoters are activated by physical means, such as the heat shock promoter. Other inducible promoters are activated by chemicals such as isopropyl-β-thiogalactopyranoside (IPTG) or Tetracycline (Tet). It is further recognized that since in most cases the exact boundaries of regulatory sequences have not been completely defined, DNA fragments of different lengths may have identical promoter activity. The “3′ non-coding sequences” refer to DNA sequences located downstream of a coding sequence and include polyadenylation recognition sequences (normally limited to eukaryotes) and other sequences encoding regulatory signals capable of affecting mRNA processing or gene expression. The polyadenylation signal (normally limited to eukaryotes) is usually characterized by affecting the addition of polyadenylic acid tracts to the 3′ end of the mRNA precursor. “RNA transcript” refers to the product resulting from RNA polymerase-catalyzed transcription of a DNA sequence. When the RNA transcript is a perfect complementary copy of the DNA sequence, it is referred to as the primary transcript or it may be a RNA sequence derived from post-transcriptional processing of the primary transcript and is referred to as the mature RNA. “Messenger RNA (mRNA)” refers to the RNA that is without introns and that can be translated into protein by the cell. “cDNA” refers to a double-stranded DNA that is complementary to and derived from mRNA. “Sense” RNA refers to RNA transcript that includes the mRNA and so can be translated into protein by the cell. “Antisense RNA” refers to a RNA transcript that is complementary to all or part of a target primary transcript or mRNA and that blocks the expression of a target gene (U.S. Pat. No. 5,107,065; WO 9928508). The complementarity of an antisense RNA may be with any part of the specific gene transcript, i.e., at the 5′ non-coding sequence, 3′ non-coding sequence, or the coding sequence. “Functional RNA” refers to antisense RNA, ribozyme RNA, or other RNA that is not translated yet has an effect on cellular processes. The term “operably linked” refers to the association of nucleic acid sequences on a single nucleic acid fragment so that the function of one is affected by the other. For example, a promoter is operably linked with a coding sequence when it is capable of affecting the expression of that coding sequence (i.e., that the coding sequence is under the transcriptional control of the promoter). Coding sequences can be operably linked to regulatory sequences in sense or antisense orientation. The term “expression”, as used herein, refers to the transcription and stable accumulation of sense (mRNA) or antisense RNA derived from the nucleic acid fragment of the invention. Expression may also refer to translation of mRNA into a polypeptide. “Transformation” refers to the transfer of a nucleic acid fragment into the genome of a host organism, resulting in genetically stable inheritance. In the present invention, the genome of the host organism is comprised the genes found on the chromosome and extrachromosomal elements (i.e. plasmids). Host organisms containing the transformed nucleic acid fragments are referred to as “transgenic” or “recombinant” or “transformed” organisms. The terms “plasmid”, “vector” and “cassette” refer to an extra chromosomal element often carrying genes which are not part of the central metabolism of the cell, and usually in the form of circular double-stranded DNA fragments. Such elements may be autonomously replicating sequences, genome integrating sequences, phage or nucleotide sequences, linear or circular, of a single- or double-stranded DNA or RNA, derived from any source, in which a number of nucleotide sequences have been joined or recombined into a unique construction which is capable of introducing a promoter fragment and DNA sequence for a selected gene product along with appropriate 3′ untranslated sequence into a cell. “Transformation cassette” refers to a specific vector containing a foreign gene and having elements in addition to the foreign gene that facilitate transformation of a particular host cell. “Expression cassette” refers to a specific vector containing a foreign gene and having elements in addition to the foreign gene that allow for enhanced expression of that gene in a foreign host. In the present invention, the terms “commercially-significant”, “commercially-suitable”, and “industrially-suitable” are used interchangeably and refer to the in vivo production of at least 3 mg/L aryl carotenoid(s) in a heterologous production host (gram negative bacteria). In another embodiment, the gram negative bacteria is capable of producing at least 4 mg/L aryl carotenoid(s) in vivo. The terms “codon optimized” or “gene optimized” refer to the modification at least one codon of the nucleotide sequence of a gene that does not modify the amino acid sequence encoded by the gene but results in increased expression levels by using codons corresponding to highly used tRNAs by the expression host. The term “comprising” means the presence of the stated features, integers, steps, or components as referred to in the claims, but that it does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. Standard recombinant DNA and molecular cloning techniques used here are well known in the art and are described by Sambrook, J., Fritsch, E. F. and Maniatis, T., Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989) (hereinafter “Maniatis”); and by Silhavy, T. J., Bennan, M. L. and Enquist, L. W., Experiments with Gene Fusions, Cold Spring Harbor Laboratory Cold Press Spring Harbor, N.Y. (1984)(hereinafter “Silhavy”); and by Ausubel, F. M. et al., Current Protocols in Molecular Biology, published by Greene Publishing Assoc. and Wiley-Interscience (1987)(hereinafter “Ausubel”). The present invention provides a method for the in vivo biotransformation of cyclic carotenoids having at least one β-ionone ring to the corresponding aryl carotenoid. The method proceeds by a) providing a gram negative host cell capable of producing a cyclic carotenoid having at least one β-ionone ring, b) transforming the gram negative host cell with a foreign crtU gene codon optimized for expression in the gram negative host cell, and c) growing the transformed gram negative host cell under conditions where aryl carotenoid is produced. Carotene Desaturase Activity Biosynthesis of aromatic carotenoids catalyzed by CrtU proceeds by desaturation and methyltransferation on the β-ionone ring of the cyclic carotenoids (Krugel et al., supra). CrtU, expressed in its native host has been shown to convert β-carotene with two β-ionone rings, to aromatic groups of isorenieratene in Streptomyces griseus, Brevibacterium linens, and Mycobacterium auraum A+ (Krugel et al., supra; Krubasik and Sandmann, Mol Gen Genet, 263:423-432 (2000); Viveiros et al., supra). A number of carotene desaturases are known and will be suitable in the present invention. For example, carotene desaturase has been identified in Streptomyces avermitilis (GenBank® Accession No. AB070934) Streptomyces griseus, (GenBank® Accession No. AF272737), Mycobacterium aurum, (GenBank® Accession No. AJ133724), Brevibacterium linens (GenBank® Accession No. AF139916), and Streptomyces coelicolor (GenBank® Accession No. AL158057), where the carotene desaturase isolated from Brevibacterium linens as described by the native and optimized sequences of crtU (SEQ ID NOs:15, 18, and 53) are preferred. One of the objects of the present invention is to increase the level of expression of a carotene desaturase gene in gram negative bacteria to effect commercially-significant levels of conversion of cyclic carotenoids to the corresponding aryl-carotenoid. One potential method for increasing expression levels is to optimize the genes for expression in the specific host. In a further embodiment, the host cell can be engineered to produce elevated levels of suitable carotenoid substrates for desaturation by a carotenoid desaturase (CrtU). Low-yields of protein in heterologous expression systems have been attributed to differences in codon usage. Difficulties in expressing heterologous genes in host strain are generally due to an extremely rare codon used by host strain and correlates with low levels of its corresponding tRNA (Apeler et al., European Journal of Biochemistry, 247: 890-895 (1997); Deng, T. L., FEBS Letters, 409: 269-272 (1997)). For example, E. coli may lack the translational machinery needed to efficiently produce proteins from the genes of gram positive bacteria that have a high content of G+C nucleotides of 65 to 70% in their DNA. Sanli et al. (US 2002146731) improved expression in E. coli by reducing the high G+C content of codons for leucine, proline, alanine, arginine, glutamate, glycine, and valine. Sampson et al. (Protein Expression and Purification, 12(3):347-352 (1998)) improved expression of Brevibacterium sterolicum cholesterol oxidase in E. coli by modifying the first 21 amino acids with high-expression E. coli codons. These changes resulted in a 60-fold improvement of expression level. The present invention relates to Brevibacterium linens crtU gene that was codon optimized for expression in a gram negative host cell (i.e. optimized for E. coli codon bias), and showed functional expression in E. coli. In this invention, PCR-based method was used to replace low-usage codons of crtU gene with high-usage codons in E. coli. Codon optimized PCR primers were designed to optimize the 5 low-usage codons of the N-terminal coding region and the 9 low-usage codons of the C-terminal coding region of crtU, and used to amplify native crtU gene from Brevibacterium linens. Production of Desaturase Substrates The present invention requires a source of substrate for the carotene desaturase. Suitable substrates are cyclic carotenoid compounds comprising a β-ionone ring. In particular, suitable substrates include, but are not limited to, β-carotene; γ-carotene; α-carotene; zeaxanthin; β-isorenieratene (φ, β-carotene); torulene; 1′,2′-dihydro-γ-carotene; 7, 8-dihydro-γ-carotene; 7′,8′-dihydro-β-carotene; 7′, 8′, 7, 8-tetrahydro-β-carotene; β-zeacarotene; echinenone; 3-OH-β-carotene; 1′,2′-dihydro-1′-OH-torulene; 16′-OH-torulene; 16′-oxo-torulene; and 16′-carboxy-torulene. Typical aryl carotenoids that will be produced by the aromatization of the β-ionone ring on the cyclic carotenoid will include, but are not limited to, isorenieratene (φ, φ-carotene); chlorobactene (φ, ψ-carotene); β-isorenieratene (φ, β-carotene); didehydro-φ, β-carotene, φ, ε-carotene; 1,2-didehydrochlorobactene; 1′, 2′-dihydrochlorobactene; 7, 8-dihydro-chlorobactene; 7′ 8′-dihydro-isorenieratene; 7′, 8′, 7, 8-tetrahydro-isorenieratene; 7′ 8′-dihydro-chlorobactene; β, φ-carotene-4-one; β, φ carotene-3-ol; 3-OH-isorenieratene; 3, 3′-dihydroxy-isorenieratene; 7′, 8′-didehydrorenieratene; OH-chlorobactene; 1′,2′-dihydro-1′-OH-didehydrochlorobactene; 16′-OH-didehydrochlorobactene; 16′-oxo-didehydrochlorobactene; and 16′-carboxy-didehydrochlorobactene. Desaturase substrates may be provided exogenously to the cells or may be produced endogenously by the cells. In the case of the latter it may be necessary to introduce additional genes for the production of various cyclic carotenoid substrates which will be drawn from the genes of the upper and/or lower carotenoid pathway. Genes Involved in Carotenoid Production. The enzyme pathway involved in the biosynthesis of carotenoids can be conveniently viewed in two parts, the upper isoprenoid pathway providing for the conversion of pyruvate and glyceraldehyde-3-phosphate to isopentenyl pyrophosphate and the lower carotenoid biosynthetic pathway, which provides for the synthesis of phytoene and all subsequently produced carotenoids. The upper and lower pathways are diagramed in FIG. 6. The upper pathway is ubiquitous in most gram negative bacteria and in these cases it will only be necessary to introduce genes that comprise the lower pathway for the biosynthesis of the desired carotenoid. The key division between the two pathways concerns the synthesis of farnesyl pyrophosphate (FPP). Where FPP is naturally present only elements of the lower carotenoid pathway will be needed. However, it will be appreciated that for the lower pathway carotenoid genes to be effective in the production of carotenoids, it will be necessary for the host cell to have suitable levels of FPP within the cell. Where FPP synthesis is not provided by the host cell, it will be necessary to introduce the genes necessary for the production of FPP. Each of these pathways will be discussed below in detail. The Upper Isoprenoid Pathway IPP biosynthesis occurs through either of two pathways. First, IPP may be synthesized through the well-known acetate/mevalonate pathway. However, recent studies have demonstrated that the mevalonate-dependent pathway does not operate in all living organisms. An alternate mevalonate-independent pathway for IPP biosynthesis has been characterized in bacteria and in green algae and higher plants (Horbach et al., FEMS Microbiol. Lett. 111:135-140 (1993); Rohmer et al, Biochem. 295: 517-524 (1993); Schwender et al., Biochem. 316: 73-80 (1996); Eisenreich et al., Proc. Natl. Acad. Sci. USA 93: 6431-6436 (1996)). Many steps in both isoprenoid pathways are known (FIG. 1). For example, the initial steps of the alternate pathway leading to the production of IPP have been studied in Mycobacterium tuberculosis by Cole et al. (Nature 393:537-544 (1998)). The first step of the pathway involves the condensation of two 3-carbon molecules (pyruvate and D-glyceraldehyde 3-phosphate) to yield a 5-carbon compound known as D-1-deoxyxylulose-5-phosphate. This reaction occurs by the DXS enzyme, encoded by the dxs gene. Next, the isomerization and reduction of D-1-deoxyxylulose-5-phosphate yields 2-C-methyl-D-erythritol-4-phosphate. One of the enzymes involved in the isomerization and reduction process is D-1-deoxyxylulose-5-phosphate reductoisomerase (DXR), encoded by the gene dxr. 2-C-methyl-D-erythritol-4-phosphate is subsequently converted into 4-diphosphocytidyl-2C-methyl-D-erythritol in a CTP-dependent reaction by the enzyme encoded by the non-annotated gene ygbP (Cole et al., supra). Recently, however, the ygbP gene was renamed as ispD as a part of the isp gene cluster (SwissProtein Accession #Q46893). Next, the 2nd position hydroxy group of 4-diphosphocytidyl-2C-methyl-D-erythritol can be phosphorylated in an ATP-dependent reaction by the enzyme encoded by the ychB gene. This product phosphorylates 4-diphosphocytidyl-2C-methyl-D-erythritol, resulting in 4-diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate. The ychB gene was renamed as ispE, also as a part of the isp gene cluster (SwissProtein Accession #P24209). Finally, the product of ygbB gene converts 4-diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate to 2C-methyl-D-erythritol 2,4-cyclodiphosphate in a CTP-dependent manner. This gene has also been recently renamed, and belongs to the isp gene cluster. Specifically, the new name for the ygbB gene is ispF (SwissProtein Accession #P36663). It is known that 2C-methyl-D-erythritol 2,4-cyclodiphosphate can be further converted into IPP to ultimately produce carotenoids in the carotenoid biosynthesis pathway. However, the reactions leading to the production of isopentenyl monophosphate from 2C-methyl-D-erythritol 2,4-cyclodiphosphate are not yet well-characterized. Several additional genes (and perhaps others) including “pyrG” (encoding a CTP synthase), “lytB” is (involved in the formation of dimethylallyl diphosphate), and “gcpE” (involved in the synthesis of 2-C-methyl-D-erythritol 4-phosphate) are thought to participate in the reactions leading to formation of isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). IPP may be isomerized to DMAPP via IPP isomerase, encoded by the idi gene, however this enzyme is not essential for survival and may be absent in some bacteria using 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. Recent evidence suggests that the MEP pathway branches before IPP and separately produces IPP and DMAPP via the IytB gene product. A IytB knockout mutation is lethal in E. coli except in media supplemented with both IPP and DMAPP. The synthesis of FPP occurs via the isomerization of IPP to dimethylallyl pyrophosphate. This reaction is followed by a sequence of two prenyltransferase reactions catalyzed by ispA, leading to the creation of geranyl pyrophosphate (GPP; a 10-carbon molecule) and farnesyl pyrophosphate (FPP; a 15-carbon molecule). Genes encoding elements of the upper pathway are known from a variety of plant, animal, and bacterial sources, as shown in Table 1. TABLE 1 Sources of Genes Encoding the Upper Isoprenoid Pathway GenBank Accession Number and Gene Source Organism dxs (D-1- AF035440, Escherichia coli deoxyxylulose 5- Y18874, Synechococcus PCC6301 phosphate AB026631, Streptomyces sp. CL190 synthase) AB042821, Streptomyces griseolosporeus AF111814, Plasmodium falciparum AF143812, Lycopersicon esculentum AJ279019, Narcissus pseudonarcissus AJ291721, Nicotiana tabacum ispC(dxr) (1-deoxy- AB013300, Escherichia coli D-xylulose 5- AB049187, Streptomyces griseolosporeus phosphate AF111813, Plasmodium falciparum reductoisomerase) AF116825, Mentha x piperita AF148852, Arabidopsis thaliana AF182287, Artemisia annua AF250235, Catharanthus roseus AF282879, Pseudomonas aeruginosa AJ242588, Arabidopsis thaliana AJ250714, Zymomonas mobilis strain ZM4 AJ292312, Klebsiella pneumoniae, AJ297566, Zea mays ispD(ygbP) (2-C- AB037876, Arabidopsis thaliana methyl-D-erythritol AF109075, Clostridium difficile 4-phosphate AF230736, Escherichia coli cytidylyltransferase) AF230737, Arabidopsis thaliana ispE(ychB) (4-diphosphocytidyl-2- AF216300, Escherichia coli C-methyl-D- AF263101, Lycopersicon esculentum erythritol kinase) AF288615, Arabidopsis thaliana ispF(ygbB) (2-C- AB038256, Escherichia coli mecs gene methyl-D-erythritol AF230738, Escherichia coli 2,4- AF250236, Catharanthus roseus (MECS) cyclodiphosphate AF279661, Plasmodium falciparum synthase) AF321531, Arabidopsis thaliana ispG(gcpE) (1- O67496, Aquifex aeolicus hydroxy-2-methyl-2- P54482, Bacillus subtilis (E)-butenyl 4- Q9pky3, Chlamydia muridarum diphosphate Q9Z8H0, Chlamydophila pneumoniae synthase) O84060, Chlamydia trachomatis P27433, Escherichia coli P44667, Haemophilus influenzae Q9ZLL0, Helicobacter pylori J99 O33350, Mycobacterium tuberculosis S77159, Synechocystis sp. Q9WZZ3, Thermotoga maritima O83460, Treponema pallidum Q9JZ40, Neisseria meningitidis Q9PPM1, Campylobacter jejuni Q9RXC9, Deinococcus radiodurans AAG07190, Pseudomonas aeruginosa Q9KTX1, Vibrio cholerae pyrG (CTP AB017705, Aspergillus oryzae synthase) AB064659, Aspergillus kawachii AF061753, Nitrosomonas europaea AF206163, Solorina crocea L22971, Spiroplasma citri M12843, E. coli M19132, Emericella nidulans M69112, Mucor circinelloides U15192, Chlamydia trachomatis U59237, Synechococcus PCC7942 U88301, Mycobacterium bovis X06626, Aspergillus niger X08037, Penicillium chrysogenum X53601, P. blakesleeanus X67216, A. brasilense Y11303, A. fumigatus Y13811, Aspergillus oryzae NM_001905, Homo sapiens CTP synthase (CTPS), mRNA NM_016748, Mus musculus cytidine 5′-triphosphate synthase (Ctps), mRNA NM_019857 Homo sapiens CTP synthase II (CTPS2), X68196 mRNA S. cerevisiae ura8 gene for CTP synthetase XM_013134 BC009408, Homo sapiens, CTP synthase, clone MGC10396 IMAGE 3355881 Homo sapiens CTP synthase II (CTPS2), mRNA XM_046801 Homo sapiens CTP synthase II (CTPS2), mRNA XM_046802 Homo sapiens CTP synthase II (CTPS2), mRNA XM_046803 Homo sapiens CTP synthase II (CTPS2), mRNA XM_046804 Homo sapiens CTP synthase II (CTPS2), mRNA Z47198, A. parasiticus pksA gene for polyketide synthase ispH(lytB) AF027189, Acinetobacter sp. BD413 AF098521, Burkholderia pseudomallei AF291696, Streptococcus pneumoniae AF323927, Plasmodium falciparum gene M87645, Bacillus subtillis U38915, Synechocystis sp. X89371, C. jejuni sp O67496 IspA (FPP AB003187, Micrococcus luteus synthase) AB016094, Synechococcus elongatus AB021747, Oryza sativa FPPS1 gene for farnesyl diphosphate synthase AB028044, Rhodobacter sphaeroides AB028046, Rhodobacter capsulatus AB028047, Rhodovulum sulfidophilum AF112881 and AF136602, Artemisia annua AF384040, Mentha x piperita D00694, Escherichia coli D13293, B. stearothermophilus D85317, Oryza sativa X75789, A. thaliana Y12072, G. arboreum Z49786, H. brasiliensis U80605, Arabidopsis thaliana farnesyl diphosphate synthase precursor (FPS1) mRNA, complete cds X76026, K. lactis FPS gene for farnesyl diphosphate synthetase, QCR8 gene for bc1 complex, subunit VIII X82542, P. argentatum mRNA for farnesyl diphosphate synthase (FPS1) X82543, P. argentatum mRNA for farnesyl diphosphate synthase (FPS2) BC010004, Homo sapiens, farnesyl diphosphate synthase (farnesyl pyrophosphate synthetase, dimethylallyltranstransferase, geranyltranstransferase), clone MGC 15352 IMAGE, 4132071, mRNA, complete cds AF234168, Dictyostelium discoideum farnesyl diphosphate synthase (Dfps) L46349, Arabidopsis thaliana farnesyl diphosphate synthase (FPS2) mRNA, complete cds L46350, Arabidopsis thaliana farnesyl diphosphate synthase (FPS2) gene, complete cds L46367, Arabidopsis thaliana farnesyl diphosphate synthase (FPS1) gene, alternative products, complete cds M89945, Rat farnesyl diphosphate synthase gene, exons 1-8 NM_002004, Homo sapiens farnesyl diphosphate synthase (farnesyl pyrophosphate synthetase, dimethylallyltranstransferase, geranyltranstransferase) (FDPS), mRNA U36376, Artemisia annua farnesyl diphosphate synthase (fps1) mRNA, complete cds XM_001352, Homo sapiens farnesyl diphosphate synthase (farnesyl pyrophosphate synthetase, dimethylallyltranstransferase, geranyltranstransferase) (FDPS), mRNA XM_034497, Homo sapiens farnesyl diphosphate synthase (farnesyl pyrophosphate synthetase, dimethylallyltranstransferase, geranyltranstransferase) (FDPS), mRNA XM_034498, Homo sapiens farnesyl diphosphate synthase (farnesyl pyrophosphate synthetase, dimethylallyltranstransferase, geranyltranstransferase) (FDPS), mRNA XM_034499, Homo sapiens farnesyl diphosphate synthase (farnesyl pyrophosphate synthetase, dimethylallyltranstransferase, geranyltranstransferase) (FDPS), mRNA XM_0345002, Homo sapiens farnesyl diphosphate synthase (farnesyl pyrophosphate synthetase, dimethylallyltranstransferase, geranyltranstransferase) (FDPS), mRNA The Lower Carotenoid Biosynthetic Pathway The division between the upper isoprenoid pathway and the lower carotenoid pathway is somewhat subjective. Because FPP synthesis is common in both carotenogenic and non-carotenogenic bacteria, the first step in the lower carotenoid biosynthetic pathway is considered to begin with the prenyltransferase reaction converting farnesyl pyrophosphate (FPP) to geranylgeranyl pyrophosphate (GGPP). The gene ciE, encoding GGPP synthetase, is responsible for this prenyltransferase reaction which adds IPP to FPP to produce the 20-carbon molecule GGPP. A condensation reaction of two molecules of GGPP occurs to form phytoene (PPPP), the first 40-carbon molecule of the lower carotenoid biosynthesis pathway. This enzymatic reaction is catalyzed by crtB, encoding phytoene synthase. In addition to C40 carotenoid biosynthesis, some microorganisms are able to make C30 carotenoids (U.S. Pat. No. 6,660,507, U.S. Ser. No. 09/941947; hereby incorporated by reference). Several genes, including crtN1, crN2, crN3, and ald encode enzymes involved in the conversion of farnesyl pyrophosphate (FPP) to C30 carotenoids. Lycopene, which imparts a “red”-colored spectra, is produced from phytoene through four sequential dehydrogenation reactions by the removal of eight atoms of hydrogen, catalyzed by the gene crtl (encoding phytoene desaturase). Intermediaries in this reaction are phytofluene, zeta-carotene, and neurosporene. Lycopene cyclase (crtY) converts lycopene to β-carotene. β-carotene is converted to zeaxanthin via a hydroxylation reaction resulting from the activity of β-carotene hydroxylase (encoded by the crtZ gene). β-cryptoxanthin is an intermediate in this reaction. β-carotene can be converted to canthaxanthin by a carotene ketolase encoded by one of the crtW, bkt, or crO genes. Echinenone in an intermediate in this reaction. Canthaxanthin can then be converted to astaxanthin by β-carotene hydroxylase encoded by the crtZ gene. Adonbirubrin is an intermediate in this reaction. Zeaxanthin can be converted to astaxanthin by a carotene ketolase encoded by one of the crtW, bkt, or crO genes. Adonixanthin is an intermediate in this reaction. Zeaxanthin can be converted to zeaxanthin-β-diglucoside. This reaction is catalyzed by zeaxanthin glucosyl transferase (crtX). Spheroidene can be converted to spheroidenone by spheroidene monooxygenase encoded by crtA. Neurosporene can be converted spheroidene and lycopene can be converted to spirilloxanthin by the sequential actions of hydroxyneurosporene synthase, methoxyneurosporene desaturase and hydroxyneurosporene-O-methyltransferase encoded by the crtC, crtD and crtF genes, respectively. Examples of genes encoding elements of the lower carotenoid biosynthetic pathway are known from a variety of plant, animal, and bacterial sources, as shown in Table 2. TABLE 2 Sources of Genes Encoding the Lower Carotenoid Biosynthetic Pathway GenBank Accession Number and Gene Source Organism crtE (GGPP AB000835, Arabidopsis thaliana Synthase) AB016043 and AB019036, Homo sapiens AB016044, Mus musculus AB027705 and AB027706, Daucus carota AB034249, Croton sublyratus AB034250, Scoparia dulcis AF020041, Helianthus annuus AF049658, Drosophila melanogaster signal recognition particle 19 kDa protein (srp19) gene, partial sequence; and geranylgeranyl pyrophosphate synthase (quemao) gene, complete cds AF049659, Drosophila melanogaster geranylgeranyl pyrophosphate synthase mRNA, complete cds AF139916, Brevibacterium linens AF279807, Penicillium paxilli geranylgeranyl pyrophosphate synthase (ggs1) gene, complete AF279808, Penicillium paxilli dimethylallyl tryptophan synthase (paxD) gene, partial cds; and cytochrome P450 monooxygenase (paxQ), cytochrome P450 monooxygenase (paxP), PaxC (paxC), monooxygenase (paxM), geranylgeranyl pyrophosphate synthase (paxG), PaxU (paxU), and metabolite transporter (pax T) genes, complete cds AJ010302, Rhodobacter sphaeroides AJ133724, Mycobacterium aurum AJ276129, Mucor circinelloides f. lusitanicus carG gene for geranylgeranyl pyrophosphate synthase, exons 1-6 D85029, Arabidopsis thaliana mRNA for geranylgeranyl pyrophosphate synthase, partial cds L25813, Arabidopsis thaliana L37405, Streptomyces griseus geranylgeranyl pyrophosphate synthase (crtB), phytoene desaturase (crtE) and phytoene synthase (crtI) genes, complete cds U15778, Lupinus albus geranylgeranyl pyrophosphate synthase (ggps1) mRNA, complete cds U44876, Arabidopsis thaliana pregeranylgeranyl pyrophosphate synthase (GGPS2) mRNA, complete cds X92893, C. roseus X95596, S. griseus X98795, S. alba Y15112, Paracoccus marcusii crtX (Zeaxanthin D90087, E. uredovora glucosylase) M87280 and M90698, Pantoea agglomerans crtY (Lycopene-β- AF139916, Brevibacterium linens cyclase) AF152246, Citrus x paradisi AF218415, Bradyrhizobium sp. ORS278 AF272737, Streptomyces griseus strain IFO13350 AJ133724, Mycobacterium aurum AJ250827, Rhizomucor circinelloides f. lusitanicus carRP gene for lycopene cyclase/phytoene synthase, exons 1-2 AJ276965, Phycomyces blakesleeanus carRA gene for phytoene synthase/lycopene cyclase, exons 1-2 D58420, Agrobacterium aurantiacum D83513, Erythrobacter longus L40176, Arabidopsis thaliana lycopene cyclase (LYC) mRNA, complete cds M87280, Pantoea agglomerans U50738, Arabodopsis thaliana lycopene epsilon cyclase mRNA, complete cds U50739, Arabidosis thaliana lycopene β cyclase mRNA, complete cds U62808, Flavobacterium ATCC21588 X74599, Synechococcus sp. Icy gene for lycopene cyclase X81787, N. tabacum CrtL-1 gene encoding lycopene cyclase X86221, C. annuum X86452, L. esculentum mRNA for lycopene β-cyclase X95596, S. griseus X98796, N. pseudonarcissus crtL (lycopene β- AAF10377.1, Deinococcus radiodurans R1 cyclase) crtI (Phytoene AB046992, Citrus unshiu CitPDS1 mRNA for phytoene desaturase) desaturase, complete cds AF039585, Zea mays phytoene desaturase (pds1) gene promoter region and exon 1 AF049356, Oryza sativa phytoene desaturase precursor (Pds) mRNA, complete cds AF139916, Brevibacterium linens AF218415, Bradyrhizobium sp. ORS278 AF251014, Tagetes erecta AF364515, Citrus x paradisi D58420, Agrobacterium aurantiacum D83514, Erythrobacter longus L16237, Arabidopsis thaliana L37405, Streptomyces griseus geranylgeranyl pyrophosphate synthase (crtB), phytoene desaturase (crtE) and phytoene synthase (crtI) genes, complete cds L39266, Zea mays phytoene desaturase (Pds) mRNA, complete cds M64704, Soybean phytoene desaturase M88683, Lycopersicon esculentum phytoene desaturase (pds) mRNA, complete cds S71770, carotenoid gene cluster U37285, Zea mays U46919, Solanum lycopersicum phytoene desaturase (Pds) gene, partial cds U62808, Flavobacterium ATCC21588 X55289, Synechococcus pds gene for phytoene desaturase X59948, L esculentum X62574, Synechocystis sp. pds gene for phytoene desaturase X68058, C. annuum pds1 mRNA for phytoene desaturase X71023, Lycopersicon esculentum pds gene for phytoene desaturase X78271, L. esculentum (Ailsa Craig) PDS gene X78434, P. blakesleeanus (NRRL1555) carB gene X78815, N. pseudonarcissus X86783, H. pluvialis Y14807, Dunaliella bardawil Y15007, Xanthophyllomyces dendrorhous Y15112, Paracoccus marcusii Y15114, Anabaena PCC7210 crtP gene Z11165, R. capsulatus crtB (Phytoene AB001284, Spirulina platensis synthase) AB032797, Daucus carota PSY mRNA for phytoene synthase, complete cds AB034704, Rubrivivax gelatinosus AB037975, Citrus unshiu AF009954, Arabidopsis thaliana phytoene synthase (PSY) gene, complete cds AF139916, Brevibacterium linens AF152892, Citrus x paradisi AF218415, Bradyrhizobium sp. ORS278 AF220218, Citrus unshiu phytoene synthase (Psy1) mRNA, complete cds AJ010302, Rhodobacter AJ133724, Mycobacterium aurum AJ278287, Phycomyces blakesleeanus carRA gene for lycopene cyclase/phytoene synthase, AJ304825, Helianthus annuus mRNA for phytoene synthase (psy gene) AJ308385, Helianthus annuus mRNA for phytoene synthase (psy gene) D58420, Agrobacterium aurantiacum L23424, Lycopersicon esculentum phytoene synthase (PSY2) mRNA, complete cds L25812, Arabidopsis thaliana L37405, Streptomyces griseus geranylgeranyl pyrophosphate synthase (crtB), phytoene desaturase (crtE) and phytoene synthase (crtI) genes, complete cds M38424, Pantoea agglomerans phytoene synthase (crtE) gene, complete cds M87280, Pantoea agglomerans S71770, Carotenoid gene cluster U32636, Zea mays phytoene synthase (Y1) gene, complete cds U62808, Flavobacterium ATCC21588 U87626, Rubrivivax gelatinosus U91900, Dunaliella bardawil X52291, Rhodobacter capsulatus X60441, L. esculentum Gtom5 gene for phytoene synthase X63873, Synechococcus PCC7942 pys gene for phytoene synthase X68017, C. annuum psyl mRNA for phytoene synthase X69172, Synechocystis sp. pys gene for phytoene synthase X78814, N. pseudonarcissus crtZ (β-carotene D58420, Agrobacterium aurantiacum hydroxylase) D58422, Alcaligenes sp. D90087, E. uredovora M87280, Pantoea agglomerans U62808, Flavobacterium ATCC21588 Y15112, Paracoccus marcusii crtW (β-carotene AF218415, Bradyrhizobium sp. ORS278 ketolase) D45881, Haematococcus pluvialis D58420, Agrobacterium aurantiacum D58422, Alcaligenes sp. X86782, H. pluvialis Y15112, Paracoccus marcusii crtO (carotenoid X86782, H. pluvialis ketolase) Y15112, Paracoccus marcusii crtU (carotenoid AF047490, Zea mays desaturase) AF121947, Arabidopsis thaliana AF139916, Brevibacterium linens AF195507, Lycopersicon esculentum AF272737, Streptomyces griseus strain IF013350 AF372617, Citrus x paradisi AJ133724, Mycobacterium aurum AJ224683, Narcissus pseudonarcissus D26095 and U38550, Anabaena sp. X89897, C. annuum Y15115, Anabaena PCC7210 crtA(spheroidene AJ010302, Rhodobacter sphaeroides monooxygenase) Z11165 and X52291, Rhodobacter capsulatus crtC AB034704, Rubrivivax gelatinosus AF195122 and AJ010302, Rhodobacter sphaeroides AF287480, Chlorobium tepidum U73944, Rubrivivax gelatinosus X52291 and Z11165, Rhodobacter capsulatus Z21955, M. xanthus crtD (carotenoid 3,4- AJ010302 and X63204, Rhodobacter sphaeroides desaturase U73944, Rubrivivax gelatinosus X52291 and Z11165, Rhodobacter capsulatus crtF (1-OH-carotenoid AB034704, Rubrivivax gelatinosus methylase) AF288602, Chloroflexus aurantiacus AJ010302, Rhodobacter sphaeroides X52291 and Z11165, Rhodobacter capsulatus crtN X73889, S. aureus By using various combinations of the genes presented in Tables 1 and 2 and the preferred genes of the present invention, innumerable different carotenoid substrates may be made using the methods of the present invention, provided sufficient sources of FPP are available in the host organism. For example, the gene cluster crtEXYIB enables the production of β-carotene. Addition of the crtZ to crtEXYIB enables the production of zeaxanthin, while the crtEXYIBZO cluster leads to production of astaxanthin and canthaxanthin. Recombinant Bacterial Expression A codon-optimized gene encoding a carotene desaturase has been recombinantly expressed in a heterologous gram negative bacterial host. Expression of crtU in recombinant bacterial hosts will be useful for 1) the production of various isoprenoid pathway intermediates, 2) the modulation of any preexisting pathway in the host cell, and 3) the synthesis of new products heretofore not possible using the host cell. Preferred heterologous host cells for expression of the instant genes and nucleic acid fragments are bacterial hosts that can be found broadly within the families Bacteroidaceae, Enterobacteriaceae, Vibrionaceae, Pasteurellae, Pseudomonadaceae and Neisseriaceae. Bacterial hosts preferred for use in the present invention will belong to genera including, but not limited to Bacteroides, Fusobacterium, Escherichia, Klebsiella, Proteus, Enterobacter, Serratia, Salmonella, Shigella, Citrobacter, Morganella, Yersinia, Erwinia, Vibrio, Aeromonas, Pasteurella, Haemophilus, Actinobacillus, Pseudomonas, Brucella, Flavobacterium, Alcaligenes, Acetobacter, Achromobacter, Acinetobacter, and Moraxella. Most preferred hosts are those of the genus Escherichia, where E. coli is particularly suitable. It will be appreciated by the skilled artisan that the expression of the present crtU genes may be regulated by controlling a number of well-known factors. For example, large-scale bacterial growth and functional gene expression may utilize a wide range of simple or complex carbohydrates, organic acids and alcohols, and saturated hydrocarbons. However, the functional genes such as crtU may be regulated, repressed or depressed by specific growth conditions, which may include the form and amount of nitrogen, phosphorous, sulfur, oxygen, carbon or any trace micronutrient, including small inorganic ions. In addition, the regulation of crtU genes may be achieved by the presence or absence of specific regulatory molecules that are added to the culture and are not typically considered nutrient or energy sources. Growth rate may also be an important regulatory factor in gene expression. Bacterial expression systems and expression vectors containing regulatory sequences that direct high-level expression of foreign proteins are well known to those skilled in the art. Any of these could be used to construct chimeric genes for expression of present carotene desaturases. These chimeric genes could then be introduced into appropriate microorganisms via transformation to provide high-level expression of the enzymes. Vectors or cassettes useful for the transformation of suitable host cells are well known in the art. Typically, the vector or cassette contains sequences directing transcription and translation of the relevant gene, a selectable marker, and sequences allowing autonomous replication or chromosomal integration. Suitable vectors comprise a region 5′ to the coding sequence which harbors transcriptional initiation controls and a region 3′ to the coding sequence which controls transcriptional termination. It is most preferred when both control regions are derived from genes homologous to the transformed host cell, although it is to be understood that such control regions need not be derived from the genes native to the specific species chosen as a production host. Initiation control regions or promoters, which are useful to drive expression of the instant coding sequences in the desired host cell, are numerous and familiar to those skilled in the art. Virtually any promoter capable of driving these genes is suitable for the present invention including, but not limited to, lac, ara, tet, trp, IPL, IPR, T7, tac, and trc. Termination control regions may also be derived from various genes native to the preferred hosts. Optionally, a termination site may be unnecessary, however, it is most preferred if included. Pathway Regulation Knowledge of the sequence of the present gene will be useful in manipulating the upper or lower carotenoid biosynthetic pathways in any organism having such a pathway. Methods of manipulating genetic pathways are common and well known in the art. Selected genes in a particularly pathway may be upregulated or down regulated by variety of methods. Additionally, competing pathways organism may be eliminated or sublimated by gene disruption and similar techniques. Once a key genetic pathway has been identified and sequenced, specific genes may be upregulated to increase the output of the pathway. For example, additional copies of the targeted genes may be introduced into the host cell on multicopy plasmids such as pBR322. Alternatively, the target genes may be modified so as to be under the control of non-native promoters. Where it is desired that a pathway operate at a particular point in a cell cycle or during a fermentation run, regulated or inducible promoters may used to replace the native promoter of the target gene. Similarly, in some cases the native or endogenous promoter may be modified to increase gene expression. For example, endogenous promoters can be altered in vivo by mutation, deletion, and/or substitution (see, Kmiec, U.S. Pat. No. 5,565,350; Zarling et al., PCT/US93/03868). Alternatively, it may be necessary to reduce or eliminate the expression of certain genes in the target pathway or in competing pathways that may serve as competing sinks for energy or carbon. Methods of down-regulating genes for this purpose have been explored. Where sequence of the gene to be disrupted is known, one of the most effective methods gene down regulation is targeted gene disruption where foreign DNA is inserted into a structural gene so as to disrupt transcription. This can be affected by the creation of genetic cassettes comprising the DNA to be inserted (often a genetic marker) flanked by sequence having a high degree of homology to a portion of the gene to be disrupted. Introduction of the cassette into the host cell results in insertion of the foreign DNA into the structural gene via the native DNA replication mechanisms of the cell. (See for example Hamilton et al., J. Bacteriol., 171:46174622 (1989), Balbas et al., Gene, 136:211-213 (1993), Gueldener et al., Nucleic Acids Res., 24:2519-2524 (1996), and Smith et al., Methods Mol. Cell. Biol., 5:270-277 (1996)). Antisense technology is another method of down regulating genes where the sequence of the target gene is known. To accomplish this, a nucleic acid segment from the desired gene is cloned and operably linked to a promoter such that the anti-sense strand of RNA will be transcribed. This construct is then introduced into the host cell and the antisense strand of RNA is produced. Antisense RNA inhibits gene expression by preventing the accumulation of mRNA that encodes the protein of interest. The person skilled in the art will know that special considerations are associated with the use of antisense technologies in order to reduce expression of particular genes. For example, the proper level of expression of antisense genes may require the use of different chimeric genes utilizing different regulatory elements known to the skilled artisan. Although targeted gene disruption and antisense technology offer effective means of down regulating genes where the sequence is known, other less specific methodologies have been developed that are not sequence based. For example, cells may be exposed to a UV radiation and then screened for the desired phenotype. Mutagenesis with chemical agents is also effective for generating mutants and commonly used substances include chemicals that affect nonreplicating DNA such as HNO2 and NH2OH, as well as agents that affect replicating DNA such as acridine dyes, notable for causing frameshift mutations. Specific methods for creating mutants using radiation or chemical agents are well documented in the art. See for example Thomas D. Brock in Biotechnology: A Textbook of Industrial Microbiology, Second Edition (1989) Sinauer Associates, Inc., Sunderland, Mass. (hereinafter “Brock”), or Deshpande, Mukund V., Appl. Biochem. Biotechnol., 36:227 (1992) (hereinafter “Deshpande”). Another non-specific method of gene disruption is the use of transposable elements or transposons. Transposons are genetic elements that insert randomly in DNA but can be latter retrieved on the basis of sequence to determine where the insertion has occurred. Both in vivo and in vitro transposition methods are known. Both methods involve the use of a transposable element in combination with a transposase enzyme. When the transposable element or transposon, is contacted with a nucleic acid fragment in the presence of the transposase, the transposable element will randomly insert into the nucleic acid fragment. The technique is useful for random mutageneis and for gene isolation, since the disrupted gene may be identified on the basis of the sequence of the transposable element. Kits for in vitro transposition are commercially available (see for example The Primer Island Transposition Kit, available from Perkin Elmer Applied Biosystems, Branchburg, N.J., based upon the yeast Ty1 element; The Genome Priming System, available from New England Biolabs, Beverly, Mass.; based upon the bacterial transposon Tn7; and the EZ::TN Transposon Insertion Systems, available from Epicentre Technologies, Madison, Wis., based upon the Tn5 bacterial transposable element). Within the context of the present invention, where there is a pre-existing carotenoid pathway in the selected host cell, it will be useful, for example to disrupt the gene encoding the ketolase encoded by crtO. This embodiment also applies to other carotenoid ketolase known in the art (i.e bkt and crtW ketolases). The gene product of crtO/crtW/bkt competes with CrtU for the same substrate, and disruption of the ketolase will be expected to enhance the enzymatic product of crtU. Industrial Production of Aryl Carotenoids Where commercial production of aryl-carotenoid compounds is desired using the present crtU gene, a variety of culture methodologies may be applied. For example, large-scale production of a specific gene product, overexpressed from a recombinant bacterial host, may be produced by either batch or continuous culture methodologies. A classical batch culturing method is a closed system where the composition of the media is set at the beginning of the culture and not subject to artificial alterations during the culturing process. Thus, at the beginning of the culturing process the media is inoculated with the desired organism or organisms and growth or metabolic activity is permitted to occur adding nothing to the system. Typically, however, a “batch” culture is batch with respect to the addition of carbon source and attempts are often made at controlling factors such as pH and oxygen concentration. In batch systems the metabolite and biomass compositions of the system change constantly up to the time the culture is terminated. Within batch cultures cells moderate through a static lag phase to a high growth log phase and finally to a stationary phase where growth rate is diminished or halted. If untreated, cells in the stationary phase will eventually die. Cells in log phase are often responsible for the bulk of production of end product or intermediate in some systems. Stationary or post-exponential phase production can be obtained in other systems. A variation on the standard batch system is the Fed-Batch system. Fed-Batch culture processes are also suitable in the present invention and comprise a typical batch system with the exception that the substrate is added in increments as the culture progresses. Fed-Batch systems are useful when catabolite repression is apt to inhibit the metabolism of the cells and where it is desirable to have limited amounts of substrate in the media. Measurement of the actual substrate concentration in Fed-Batch systems is difficult and is therefore estimated on the basis of the changes of measurable factors such as pH, dissolved oxygen, and the partial pressure of waste gases such as CO2. Batch and Fed-Batch culturing methods are common and well known in the art and examples may be found in Brock (supra) and Deshpande (supra). Commercial production of aryl-carotenoids may also be accomplished with a continuous culture. Continuous cultures are an open system where a defined culture media is added continuously to a bioreactor and an equal amount of conditioned media is removed simultaneously for processing. Continuous cultures generally maintain the cells at a constant high-liquid-phase density where cells are primarily in log phase growth. Alternatively, continuous culture may be practiced with immobilized cells where carbon and nutrients are continuously added and valuable products, by-products or waste products are continuously removed from the cell mass. Cell immobilization may be performed using a wide range of solid supports composed of natural and/or synthetic materials. Continuous or semi-continuous culture allows for the modulation of one factor or any number of factors that affect cell growth or end product concentration. For example, one method will maintain a limiting nutrient such as the carbon source or nitrogen level at a fixed rate and allow all other parameters to moderate. In other systems a number of factors affecting growth can be altered continuously while the cell concentration, measured by media turbidity, is kept constant. Continuous systems strive to maintain steady-state growth conditions and thus the cell loss due to media being drawn off must be balanced against the cell growth rate in the culture. Methods of modulating nutrients and growth factors for continuous culture processes, as well as techniques for maximizing the rate of product formation, are well known in the art of industrial microbiology and a variety of methods are detailed by Brock (supra). Fermentation media in the present invention must contain suitable carbon substrates. Suitable substrates may include, but are not limited to, monosaccharides such as glucose and fructose, oligosaccharides such as lactose or sucrose, polysaccharides such as starch or cellulose or mixtures thereof, and unpurified mixtures from renewable feedstocks such as cheese whey permeate, cornsteep liquor, sugar beet molasses, and barley malt. Hence, it is contemplated that the source of carbon utilized in the present invention may encompass a wide variety of carbon containing substrates and will only be limited by the choice of organism. λ-Red Recombinase System Various genetic systems were used herein to express portions of the lower carotenoid biosynthetic pathway. In particular the λ-red recombinase system in combination with a bacteriophage P1 transduction system and various integration cassettes were used to engineer the appropriate gram negative host for substrate production. The λ-Red recombinase system used in the present invention is contained on a helper plasmid (pKD46; SEQ ID NO:55)) and is comprised of three essential genes, exo, bet, and gam (Datsenko and Wanner, supra). The exo gene encodes an γ-exonuclease, which processively degrades the 5′ end strand of double-stranded (ds) DNA and creates 3′ single-stranded overhangs. Bet encodes for a protein which complexes with the λ-exonuclease and binds to the single stranded DNA and promotes renaturation of complementary strands and is capable of mediating exchange reactions. Gam encodes for a protein that binds to the E.coli's RecBCD complex and blocks the complex's endonuclease activity. The λ-Red system is used in the present invention because homologous recombination in E.coli occurs at a very low frequency and usually requires extensive regions of homology. The λ-Red system facilitates the ability to use short regions of homology (10-50 bp) flanking linear double-stranded (ds) DNA fragments for homologous recombination. Additionally, the RecBCD complex normally expressed in E.coli prevents the use of linear dsDNA for transformation as the complex's exonuclease activity efficiently degrades linear dsDNA. Inhibition of the RecBCD complex's endonuclease activity by gam is essential for efficient homologous recombination using linear dsDNA fragments. Integration Cassettes As used in the present invention, “integration cassettes” are the linear double-stranded DNA fragments chromosomally integrated by triple homologous recombination via two PCR-generated linear fragments as seen in FIGS. 3 and 4. The integration cassette comprises a nucleic acid integration fragment that is a promoter and/or gene, a selectable marker bounded by specific recombinase sites responsive to a recombinase, and homology arms having homology to different portions of a donor cell chromosome. The homology arms, generally about 10 to 50 base pairs in length, are chosen so have homology with either a specific sequence on the bacterial chromosome or a specific sequence on another recombination element. In the present invention, the native promoter of the isoprenoid genes is replaced with the phage T5 strong promoter in combination with a selection marker by using one or two linear dsDNA PCR-generated fragments (FIG. 3). Integration cassettes may contain one or more genes or coding sequences. These genes may be natural or foreign to the host cell and may include those which have undergone previous modification, such as transposon disruption. In the present method, genes useful in optimization of isoprenoid/carotenoid production are used. The genes of the isoprenoid biosynthetic pathway are selected from the group consisting of dxs, dxr, ygbP, ychB, ygbB, idi, ispA, lytB, gcpE, pyrG, ispB, crtE, crtY, crtL, crtI, crtB, crtx, crtZ, crtW, crtO, crtA, crtC, crtD, crtF, crtN1, crtN2, crtN3, ald, crtU, and homologs thereof from other microorganisms. Integration cassettes can include selectable markers, preferably flanked by site-specific recombination sequences, allowing for easy removal of the markers after selection. The selectable marker is selected from the group consisting of antibiotic resistance markers, enzymatic markers wherein the expressed marker catalyzes a chemical reaction creating a measurable difference in phenotypic appearance, and amino acid biosynthesis enzymes which enable a normally auxotrophic bacteria to grow without the exogenously supplied amino acid; the amino acid synthesized by the amino acid biosynthesis enzyme. Bacteriophage P1 Transduction System Transduction is a phenomenon in which bacterial DNA is transferred from one bacterial cell (the donor) to another (the recipient) by a phage particle containing bacterial DNA. When a population of donor bacteria is infected with a phage, the events of the phage lytic cycle may be initiated. During lytic infection, the enzymes responsible for packaging viral DNA into the bacteriophage sometimes accidentally package host DNA. The resulting particle is called a transducing particle. Upon lysis of the cell these particles, called P1 lysate, are released along with normal virions, and so the lysate contains a mixture of normal virions and transducing particles. When this lysate is used to infect a population of recipient cells, most of the cells become infected with normal virus. However, a small proportion of the population receives transducing particles that inject the DNA they received from the previous host bacterium. This DNA can now undergo genetic recombination with the DNA of another host. Conventional P1 transduction can move only one genetic trait (i.e. gene) at a time from one to another host. The Applicants used a system for stacking multiple genetic traits into one E. coli host in a parallel fashion using the bacteriophage P1 mixtures in combination with the site-specific recombinase system for removal of selection markers (U.S. Ser. No. 10/734778). DESCRIPTION OF THE PREFERRED EMBODIMENTS The present codon-optimized crtU genes, encoding carotene desaturase, are useful for the creation of recombinant organisms capable of producing aryl-carotenoid compounds. Nucleic acid fragments encoding CrtU have been isolated from a strain of Brevibacterium linens, codon-optimized for expression in a gram negative host, and subsequently expressed in Escherichia coli. Applicants have isolated the crtu gene (SEQ ID NO:15) and amplified it by PCR from Brevibacterium linens ATCC 9175 (Example 4). In one embodiment, the crtU gene from B. linens was codon-optimized for recombinant expression in a gram negative heterologous host. In a more preferred embodiment, the optimized crtU gene (SEQ ID NOs:18 or 53) contained 5 codon substitutions at the 5′ end of the gene and 9 codon substitutions at the 3′ end creating a codon-optimized gene encoding a polypeptide having the amino acid sequence setfor in SEQ ID NO:19. In another preferred embodiment, the codon-optimized gene was expressed in E. coli (Examples 5-7). The heterologous host cells were genetically modified to express carotenoid biosynthesis genes for the production of carotenoids having at least one β-ionone ring. In another embodiment, the codon optimized crtU gene was expressed in a heterologous host cell capable of producing a carotenoid substrate having at least one β-ionone ring for the production of aryl carotenoids (Example 5; FIG. 1). The carotenoid substrate, comprising at least one β-ionone ring, was converted by the expressed carotene desaturase (codon-optimized crtU) into an aryl carotenoid product. In a preferred embodiment, the heterologous host was a strain of Escherichia coli. In another preferred embodiment, the carotenoid biosynthesis genes were from the Pantoea stewartii crt gene cluster (Examples 1-3). In another embodiment, the carotene desaturase gene and one or more of the carotenoid biosynthesis genes were extrachromosomally expressed. In another embodiment, one or more of the genes of the present invention were chromosomally expressed. In another embodiment, the lycopene cyclase expressed in the heterologous host cell selectively produced only monocyclic (single β-ionone ring) carotenoids (FIG. 1). In a preferred embodiment, the lycopene cyclase gene (crtL) from Rhodococcus erythropolis strain AN12, encoding a polypeptide having the amino acid sequence as described in SEQ ID NO:50, was used (Examples 15-17). The lycopene cyclase encoded by this gene has been reported to selectively produce monocyclic carotenoids (U.S. Ser. No. 10/292577). In a preferred embodiment, the monocyclic carotenoid produced was γ-carotene. In a more preferred embodiment, the codon-optimized carotene desaturase converted γ-carotene into chlorobactene (FIG. 1). In another embodiment, the lycopene cyclase expressed in the heterologous host cell produces bicyclic carotenoids (two β-ionone rings) (FIG. 1). In a preferred embodiment, the lycopene cyclase used (SEQ ID NO:6) was from Pantoea stewartii (ATCC 8199). The bicyclic carotenoid produced using the lycopene cyclase (crtY) from Pantoea stewartii (ATCC 8199) was β-carotene. The codon-optimized carotene desaturase converted the β-carotene substrate produced by CrtY into β-isorenieratene and/or isorenieratene (Examples 5 and 10). The Applicants show how to chromosomally-modify the heterologous host cell for increased expression of isoprenoid and/or carotenoid biosynthesis genes (Examples 7-9, and 11-14; FIG. 2). In a preferred embodiment, the promoters of the isoprenoid and/or carotenoid biosynthesis gene were replaced with a stronger promoter (FIG. 3). In a more preferred embodiment, the promoter was the phage T5 promoter (PT5) (SEQ ID NO:57). In another preferred embodiment, the promoters for the dxs, idi, and ygbBygbP genes were replaced with PT5 for increased carotenoid production (FIG. 3). The carotenoid biosynthesis genes were chromosomally integrated into the heterologous host cell (Examples 12-14; FIG. 4). In a preferred embodiment, the chromosomally integrated carotenoid biosynthesis genes were genetically-engineered, replacing their natural promoters with a stronger promoter. In a more preferred embodiment, the carotenoid biosynthesis genes were expressed using the PT5 promoter. In another embodiment, the various genetically engineered genes were incorporated into a single heterologous host using trait stacking (Examples 8-9, 11, and 14; FIG. 3). In a preferred embodiment, the trait stacking was accomplished by P1 transduction. In another embodiment, the codon optimized crtU gene is expressed in a gram negative host cell engineered for increased production of suitable carotenoid substrates. In another embodiment, one or more genes of the isoprenoid or carotenoid biosynthesis pathway are overexpressed. In another embodiment, one or more genes competing with the CrtU from the pool of suitable carotenoid substrates is down-regulated or knocked-out (i.e. carotenoid ketolases). In yet another embodiment, the gram negative host cell is E. coli strain DPR676 (ATCC# PTA-5136). In a further embodiment, the gram negative host cell produces aryl carotenoids at industrially-suitable levels. In yet a further embodiment, the gram negative host cell is capable of producing at least 3 mg/L aryl carotenoid during fermentation. In another embodiment, carotene desaturase can be used as a catalyst for production of aryl carotenoids. The carotene desaturase catalyst can be used in the form of whole cells, partially purified components of a whole cell, and partially-purified or purified components enzymes. The catalyst can be immobilized in a soluble or insoluble support. In a preferred embodiment, the purified catalyst is contacted with a β-ionone ring containing carotenoid substrate for the production of aryl carotenoids. EXAMPLES The present invention is further defined in the following Examples. It should be understood that these Examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. General Methods Standard recombinant DNA and molecular cloning techniques used in the Examples are well known in the art and are described by Maniatis (supra), Silhavy (supra), and Ausubel (supra). Materials and methods suitable for the maintenance and growth of bacterial cultures are well known in the art. Techniques suitable for use in the following examples may be found as set out in Manual of Methods for General Bacteriology (Phillipp Gerhardt, R. G. E. Murray, Ralph N. Costilow, Eugene W. Nester, Willis A. Wood, Noel R. Krieg and G. Briggs Phillips, eds), American Society for Microbiology, Washington, DC. (1994)) or Brock (supra). All reagents, restriction enzymes and materials used for the growth and maintenance of bacterial cells were obtained from Aldrich Chemicals (Milwaukee, Wis.), DIFCO Laboratories (Detroit, Mich.), GIBCO/BRL (Gaithersburg, Md.), or Sigma Chemical Company (St. Louis, Mo.) unless otherwise specified. Manipulations of genetic sequences were accomplished using the suite of programs available from the Genetics Computer Group Inc. (Wisconsin Package Version 9.0, Genetics Computer Group (GCG), Madison, Wis.). The GCG program “Pileup” used the gap creation default value of 12 and the gap extension default value of 4. The CGC “Gap” or “Bestfit” programs used the default gap creation penalty of 50 and the default gap extension penalty of 3. Multiple alignments were created using the FASTA program incorporating the Smith-Waterman algorithm (W. R. Pearson, Comput. Methods Genome Res., [Proc. Int. Symp.] (1994), Meeting Date 1992, 111-20. Editor(s): Suhai, Sandor. Publisher: Plenum, New York, N.Y.). In any case where program parameters were not prompted for, in these or any other programs, default values were used. The meaning of abbreviations is as follows: “h” means hour(s), “min” means minute(s), “sec” means second(s), “d” means day(s), “mL” means milliliters, “L” means liters, “μL” means microliters, “μg” mean micrograms, and “rpm” means revolutions per minute. Example 1 Cloning of Genes for β-carotene Synthesis from Pantoea Stewartii Primers were designed using the sequence from Erwinia uredovora to amplify a fragment by PCR containing the crt genes. These sequences included 5′-3′: ATGACGGTCTGCGCAAAAAAACACG SEQ ID NO:13 GAGAAATTATGTTGTGGATTTGGAATGC SEQ ID NO:14 Chromosomal DNA was purified from Pantoea stewartii (ATCC no. 8199) and Pfu Turbo polymerase (Stratagene, La Jolla, Calif.) was used in a PCR amplification reaction under the following conditions: 94° C., 5 min; 94° C. (1 min)-60° C. (1 min)-72° C. (10 min) for 25 cycles, and 72° C. for 10 min. A single product of approximately 6.5 kb was observed following gel electrophoresis. Taq polymerase (Perkin Elmer) was used in a ten minute 72° C. reaction to add additional 3′ adenosine nucleotides to the fragment for TOPO cloning into pCR4-TOPO (Invitrogen, Carlsbad, Calif.) to create pPCB13. Following transformation to E. coli DH5α (Life Technologies, Rockville, Md.) by electroporation, several colonies appeared to be bright yellow in color indicating that they were producing a carotenoid compound. Following plasmid isolation as instructed by the manufacturer using the Qiagen (Valencia, Calif.) miniprep kit, the plasmid containing the 6.5 kb amplified fragment was transposed with pGPS1.1 using the GPS-1 Genome Priming System kit (New England Biolabs, Inc., Beverly, Mass.). A number of these transposed plasmids were sequenced from each end of the transposon. Sequence was generated on an ABI Automatic sequencer using dye terminator technology (U.S. Pat. No. 5,366,860; EP 272007) using transposon specific primers. Sequence assembly was performed with the Sequencher program (Gene Codes Corp., Ann Arbor, Mich.). Example 2 Identification and Characterization of Bacterial Genes Genes encoding crtE, X, Y, I, B, and Z were identified by conducting BLAST (Basic Local Alignment Search Tool; Altschul et al., J. Mol. Biol. 215:403-410 (1993)) searches for similarity to sequences contained in the BLAST “nr” database (comprising all non-redundant GenBank® CDS translations, sequences derived from the 3-dimensional structure Brookhaven Protein Data Bank, the SWISS-PROT protein sequence database, EMBL, and DDBJ databases). The sequences obtained in Example 1 were analyzed for similarity to all publicly available DNA sequences contained in the “nr” database using the BLASTN algorithm provided by the National Center for Biotechnology Information (NCBI). The DNA sequences were translated in all reading frames and compared for similarity to all publicly available protein sequences contained in the “nr” database using the BLASTX algorithm (Gish, W. and States, D. J., Nature Genetics, 3:266-272 (1993)) provided by the NCBI. All comparisons were done using either the BLASTNnr or BLASTXnr algorithm. The results of the BLAST comparisons are given in Table 3, listing the sequences to which they have the most similarity. Table 3 displays data based on the BLASTXnr algorithm with values reported in expect values. The Expect value estimates the statistical significance of the match, specifying the number of matches, with a given score, that are expected in a search of a database of this size absolutely by chance. TABLE 3 ORF Gene SEQ ID SEQ ID % % Name Name Similarity Identified base Peptide Identitya Similarityb E-valuec Citation 1 crtE Geranylgeranyl pryophosphate synthetase 1 2 83 88 e−137 Misawa et EC 2.5.1.29 al., J. gi|117509|sp|P21684|CRTE_PANAN Bacteriol. GERANYLGERANYL PYROPHOSPHATE 172 (12), SYNTHETASE (GGPP SYNTHETASE) 6704-6712 (FARNESYL TRANSTRANSFERASE) (1990) 2 crtX Zeaxanthin glucosyl transferase EC 2.4.1.- 3 4 75 79 0.0 Lin et al., gi|1073294|pir||S52583 crtX protein - Erwinia Mol. Gen. herbicola Genet. 245 (4), 417- 423 (1994) 3 crtY Lycopene cyclase 5 6 83 91 0.0 Lin et al., gi|1073295|pir||S52585 lycopene cyclase - Mol. Gen. Erwinia herbicola Genet. 245 (4), 417- 423 (1994) 4 crtl Phytoene desaturase EC 1.3.-.- 7 8 89 91 0.0 Lin et al., gi|1073299|pir||S52586 phytoene Mol. Gen. dehydrogenase (EC 1.3.-.-) - Erwinia Genet. 245 herbicola (4), 417- 423 (1994) 5 crtB Phytoene synthase EC 2.5.1.- 9 10 88 92 e−150 Lin et al., gi|1073300|pir||S52587 prephytoene Mol. Gen. pyrophosphate synthase - Erwinia herbicola Genet. 245 (4), 417- 423 (1994) 6 crtZ Beta-carotene hydroxylase 11 12 88 91 3e−88 Misawa et gi|117526|sp|P21688|CRTZ_PANAN BETA- al., J. CAROTENE HYDROXYLASE Bacteriol. 172 (12), 6704-6712 (1990) a% Identity is defined as percentage of amino acids that are identical between the two proteins. b% Similarity is defined as percentage of amino acids that are identical or conserved between the two proteins. cExpect value. The Expect value estimates the statistical significance of the match, specifying the number of matches, with a given score, that are expected in a search of a database of this size absolutely by chance. Example 3 Analysis of crt Gene Function by Transposon Mutagenesis Several plasmids carrying transposons that were inserted into each coding region including crtE, crtX, crtY, crtI, crtB, and crtZ were chosen using sequence data generated in Example 1. These plasmid variants were transformed to E. coil MG1655 and grown in 100 mL Luria-Bertani broth in the presence of 100 μg/mL ampicillin. Cultures were grown for 18 h at 26° C., and the cells were harvested by centrifugation. Carotenoids were extracted from the cell pellets using 10 mL of acetone. The acetone was dried under nitrogen and the carotenoids were resuspended in 1 mL of methanol for HPLC analysis. A Beckman System Gold® HPLC with Beckman Gold Nouveau Software (Columbia, Md.) was used for the study. The crude extraction (0.1 mL) was loaded onto a 125×4 mm RP8 (5 μm particles) column with corresponding guard column (Hewlett-Packard, San Fernando, Calif.). The flow rate was 1 mL/min, while the solvent program used was: 0-11.5 min 40% water/60% methanol; 11.5-20 min 100% methanol; 20-30 min 40% water/60% methanol. The spectrum data were collected by a Beckman photodiode array detector (model 168). In the wild-type clone with wild-type crtEXYIBZ, the carotenoid was found to have a retention time of 15.8 min and an absorption spectra of 450 nm, 475 nm. This was the same as the β-carotene standard. This suggested that the crtZ gene, oriented in the opposite direction, was not expressed in this construct. The transposon insertion in crtZ had no effect as expected (data not shown). HPLC spectral analysis also revealed that a clone with a transposon insertion in crtx also produced β-carotene. This is consistent with the proposed function of crtx encoding a zeaxanthin glucosyl transferase enzyme at a later step of the carotenoid pathway following synthesis of β-carotene. The transposon insertion in crtY did not produce β-carotene. The carotenoid's elution time (15.2 min) and absorption spectra (443 nm, 469 nm, 500 nm) agree with those of the lycopene standard. Accumulation of lycopene in the crtY mutant confirmed the role crtY as a lycopene cyclase encoding gene. The crtl extraction, when monitored at 286 nm, had a peak with retention time of 16.3 min and with absorption spectra of 276 nm, 286 nm, 297 nm, which agrees with the reported spectrum for phytoene. Detection of phytoene in the crtl mutant confirmed the function of the crtl gene as one encoding a phytoene dehydrogenase enzyme. The extraction of crtE mutant, crtB mutant or crtl mutant was clear. Loss of pigmented carotenoids in these mutants indicated that both the crtE gene and citB gene are essential for carotenoid synthesis. No carotenoid was observed in either mutant, which is consistent with the proposed function of crtB encoding a prephytoene pyrophosphate synthase and crtE encoding a geranylgeranyl pyrophosphate synthetase. Both enzymes are required for β-carotene synthesis. Results of the transposon mutagenesis experiments are shown below in Table 4. The site of transposon insertion into the gene cluster crtEXYIB is recorded, along with the color of the E. coli colonies observed on LB plates, the identity of the carotenoid compound (as determined by HPLC spectral analysis), and the experimentally assigned function of each gene. TABLE 4 Transposon Carotenoid Assigned insertion Colony observed gene site color by HPLC function Wild Type Yellow β-carotene (with no transposon insertion) crtE White None Geranylgeranyl pyrophosphate synthetase crtB White None Prephytoene pyrophosphate synthase crtI White Phytoene Phytoene dehydrogenase crtY Pink Lycopene Lycopene cyclase crtZ Yellow β-carotene β-carotene hydroxylase crtX Yellow β-carotene Zeaxanthin glucosyl transferase Example 4 Synthesis of a crtU Gene Optimized for Expression in E. coli A linear DNA fragment encoding a crtU gene was synthesized by PCR using the Brevibacterium linens (ATCC 9175) crtU genomic DNA (SEQ ID NO:15) as template with primer pairs: 1) crtU-F (SEQ ID NO:16), ATGACCCAGCGTCGCCGCCCGCGCGATCGCTTCGCCGAGAGMTCC AGGGCCCGCAG which contains a region modified from the original B. linens sequence (underlined, 24 bp) and a priming sequence (33 bp) matching the B. linens sequence; and 2) crtU-R (SEQ ID NO:17), TCAGCGACGGCGGCGGATCAGGCCCAGCACGCCACGGCGCAGCAG GCCTCGGGTCGGTGGCGAC which contains a region modified from the B. linens sequence (underlined, 42 bp) and a priming sequence (22 bp) matching the B. linens sequence. A 1554 bp product was generated and was predicted to contain 5 codon substitutions at the 5′ end of the B. linens crtU gene and 9 codon substitutions at the 3′ end (SEQ ID NO:18). All of these substitutions are silent. The PCR reaction was performed using the Perkin Elmer PCR 9700 thermocycler (Perkin Elmer Corporation, Foster City, Calif.), the High Fidelity PCR Supermix (Invitrogen, Carlsbad, Calif.), 45 μL, and 1 μL of each primer and the B. linens crtU gene (SEQ ID NO:15) as template as described by the manufacturer. The temperature parameters were as follows: 98° C. (10 min), 31 cycles 98° C. (1 min)-60° C. (1 min)-72° C. (2 min), followed by 72° C. (10 min). The 1554 bp PCR product was purified by QIAquick PCR purification kit (Qiagen, Valencia, Calif.). Then the 1.5 kb band from the PCR product was purified by gel extraction using Zymoclean gel DNA recovery kit (Zymo Research, Orange, Calif.). Sequencing of the 1554 bp product revealed an additional silent mutation generated by PCR at position 825 (SEQ ID NO:53). A thymine (T) residue was substituted for the wild-type cytosine (C). The predicted amino acid sequence was not affected by this silent mutation. Example 5 Cloning of the Optimized crtU Gene and Expression in a β-carotene Producing E. coli for Production of Isorenieratene The modified crtU PCR fragment (SEQ ID NO:53) was cloned into pTrcHis2-TOPO vector by using pTrcHis2-TOPO TA Expression kit (Invitrogen, Carlsbad, Calif.). A 4 μL aliquot of the modified crtU PCR product recovered from gel extraction in Example 4 was mixed with 1 μL pTrcHis2-TOPO vector and incubated 5 min at room temp. A 2 μL aliquot of this PCR product-vector mixture was transformed into One Shot E. coli competent cells (Invitrogen) by heat-shock. Transformants were selected on 100 μg/mL of ampicillin LB plate at 37° C. Plasmids were isolated from resulting colonies and analyzed by restriction enzyme digestion to verify plasmid construct. The DNA sequence of the insert was verified by sequencing. The final construct was named pTrcHis2-TOPO-crtU. The pTrcHis2-TOPO-crtU plasmid was transformed into E.coli strain MG1655 harboring the pBHR-crt+plasmid. pBHR-crt+carries a carotenoid biosynthetic gene cluster from Pantoea stewartii, as described in Examples 1 and 2, cloned into the EcoRI site of pBHR1 (MoBiTec, Goettingen, Germany) such that expression of the crtEBIY genes was driven by the promoter of the chloramphenicol resistance gene. Transformants were selected on 100 μg/mL of ampicillin and 50 μg/mL of kanamycin LB plate at 37° C. Colonies that appeared yellow were inoculated into 100 mL LB with 100 μg/mL of ampicillin, 50 μg/mL of kanamycin and 1 mM IPTG. After incubation 12 to 18 hours at 37° C. with shaking at 250 rpm, the cultures were centrifuged at 8000 rpm for 10 min at 4° C. A 2 mL aliquot of acetone was added to the pellet and the mixture was vortexed 2 min to extract the carotenoid pigments. The mixture was centrifuged in a microcentrifuge to separate the cell debris. After filtration with an Acrodisc CR25 mm syringe filter (Pall Corporation, Ann Arbor, Mich.), the acetone fraction was analyzed by HPLC (Beckman System Gold, Fullerton, Calif.) using column of SUPELCO discovery C18 (5 μm, 4.6×250 mm). Liquid chromatography was performed with flow rate of 2.0 mL/min. The elution was initiated at 0% acetone and ends in 20 minutes with 50% acetone in linear gradient change. HPLC analysis indicated that E. coli strain MG1655 with plasmid pBHR-crt+ and plasmid pTrcHis2-TOPO-crtU produced the isorenieratene (49.4% total extractable pigment) and β-isorenieratene (21.1% of total extractable pigment) and β-carotene (29.5% of total extractable pigment). The resulting solution with pigments was analyzed by an Agilent Series 1100 LC/MSD (Agilent, Foster City, Calif.). Liquid chromatography was performed using a SB-C18 (5 μm, 4.6×250 mm) column (Agilent) with flow rate of 1.5 mL/min. The elution was initiated with a 52 mL linear solvent gradient from acetonitrile to 60% acetone and 40% acetonitrile. MS analysis confirmed the presence of isorenieratene (molecular weight of 529), β-isorenieratene (molecular weight of 533), and β-carotene (molecular weight of 537). Example 6 Protein Gel Electrophoresis of the Optimized crtU Gene Product in E. coli E. coli MG1655 with plasmid pBHR-crt+ and plasmid pTrcHis2-TOPO-crtU was inoculated into 100 mL LB with 100 μg/mL of ampicillin, 50 μg/mL of kanamycin and 1 mM IPTG. A 5 mL culture aliquot was centrifuged to pellet cells. All pellets were resuspended in 150 μL B-Per II solution (Pierce, Rockford, Ill.) and vortexed to mix well. After 5 min in a microcentrifuge, the supernatant was isolated and mixed with 4×sample buffer (Invitrogen) to final 1×concentration and incubated at 95° C. for 5 min. A 10 μL aliquot from each sample was loaded onto a pre-cast 4-12% Bis-Tris gel (Invitrogen). Following electrophoresis, the gel was stained using SimplyBlue Safestain (Invitrogen) and de-stained with water. All samples proven to produce isorenieratene by HPLC contained a unique band at 57 kDa. The 57 kDa band was not observed in extracts from the E. coli strain carrying plasmid pBHR-crt+ alone or from an E. coli strain with pBHRl-crt+ and pTrcHis2-TOPO with the optimized crtU cloned in the opposite orientation of the promoter. Example 7 Construction of E. coli Strains with the Phage T5 Strong Promoter Chromosomally Integrated Upstream of the Isoprenoid Genes The native promoters of the E. coli isoprenoid genes dxs, idi, and ygbBygbP (FIG. 2) were replaced with the phage T5 (PT5) strong promoter (SEQ ID NO:57) using a PCR-fragment chromosomal integration method as described in FIG. 3. The method for replacement is based on homologous recombination via the λ-Red recombinase encoded on a helper plasmid. Recombination occurs between the E. coli chromosome and two PCR fragments that contain 20-50 bp homology patches at both ends of PCR fragments (FIG. 3). A two PCR fragment method was used for chromosomal integration of the kanamycin selectable marker and phage T5 promoter in the front of the E. coli isoprenoid genes dxs, idi, and ygbBygbP (U.S. Ser. No. 10/735442, hereby incorporated by reference). For the two PCR fragment method, the two fragments included a linear DNA fragment (1489 bp) containing a kanamycin selectable marker flanked by site-specific recombinase target sequences (FRT) and a linear DNA fragment (154 bp) containing a phage T5 promoter (PT5) comprising the −10 and −35 consensus promoter sequences, lac operator (lacO), and a ribosomal binding site (RBS). By using the two PCR fragment method, the kanamycin selectable marker and phage T5 promoter (kan-PT5) were integrated upstream of the dxs, idi, and ygbBygbP coding sequences, yielding E. coli kan-PT5-dxs, E. coli kan-PT5-idi, and E. coli kan-PT5-ygbBygbP. The linear DNA fragment (1489 bp), which contained a kanamycin selectable marker, was synthesized by PCR from plasmid pKD4 (Datsenko and Wanner, supra) with primer pairs as follows in Table 5. TABLE 5 Primers for Amplification of the Kanamycin Selectable Marker SEQ ID Primer Name Primer Sequence NO: 5′-kan(dxs) TGGAAGCGCTAGCGGACTACATCATCCAGCGTAAT 20 AAATAACGTCTTGAGCGATTGTGTAG1 5′-kan(idi) TCTGATGCGCAAGCTGAAGAAAAATGAGCATGGAG 21 AATAATATGACGTCTTGAGCGATTGTGTAG1 5′-kan(ygbBP) GACGCGTCGAAGCGCGCACAGTCTGCGGGGCAAA 22 ACAATCGATAACGTCTTGAGCGATTGTGTAG1 3′-kan GAAGACGAAAGGGCCTCGTGATACGCCTATTTTTAT 23 AGGTTATATGAATATCCTCCTTAGTTCC2 1The underlined sequences illustrate each respective homology arm chosen to match sequences in the upstream region of the chromosomal integration site, while the remainder is the priming sequence) 2The underlined sequences illustrate homology arm chosen to match sequences in the 5′-end region of the T5 promoter DNA fragment The second linear DNA fragment (154 bp) containing a phage T5 promoter was synthesized by PCR from pQE30 (QIAGEN, Inc. Valencia, Calif.) with primer pairs as follows in Table 6. TABLE 6 Primers for Amplification of the T5 Promoter SEQ ID Primer Name Primer Sequence NO: 5′-T5 CTAAGGAGGATATTCATATAACCTATAAAAATAG 24 GCGTATCACGAGGCCC3 3′-T5(dxs) GGAGTCGACCAGTGCCAGGGTCGGGTATTTGGC 25 AATATCAAAACTCATAGTTAATTTCTCCTCTTTAAT G4 3′-T5(idi) TGGGAACTCCCTGTGCATTCAATAAAATGACGTG 26 TTCCGTTTGCATAGTTAATTTCTCCTCTTTAATG4 3′-T5(ygbBP) CGGCCGCCGGAACCACGGCGCAAACATCCAAAT 27 GAGTGGTTGCCATAGTTAATTTCTCCTCTTTAATG4 3The underlined sequences illustrate homology arm chosen to match sequences in the 3′-end region of the kanamycin DNA fragment 4The underlined sequences illustrate each respective homology arm chosen to match sequences in the downstream region of the chromosomal integration site Standard PCR conditions were used to amplify the linear DNA fragments with AmpliTaq Gold® polymerase (Applied Biosystems, Foster City, Calif.) as follows: PCR reaction: PCR reaction mixture: Step1 94° C. 3 min 0.5 μL plasmid DNA Step2 93° C. 30 sec 5 μL 10× PCR buffer Step3 55° C. 1 min 1 μL dNTP mixture (10 mM) Step4 72° C. 3 min 1 μL 5′-primer (20 μM) Step5 Go To Step2, 30 cycles 1 μL 3′-primer (20 μM) Step6 72° C. 5 min 0.5 μL AmpliTaq Gold ® polymerase 41 μL sterilized dH2O After completing the PCR reactions, 50 μL of each PCR reaction mixture was run on a 1% agarose gel and the PCR products were purified using the QIAquick Gel Extraction Kit™ as per the manufacturer's instructions (Cat. # 28704, QIAGEN Inc., Valencia, Calif.). The PCR products were eluted with 10 μL of distilled water. The DNA Clean & Concentrator™ kit (Zymo Research, Orange, Calif.) was used to further purify the PCR product fragments as per the manufacturer's instructions. The PCR products were eluted with 6-8 μL of distilled water to a concentration of 0.5-1.0 μg/μL. E. coli strain MC1061, carrying the λ-Red recombinase expression plasmid pKD46 (ampR) (Datsenko and Wanner, supra; SEQ ID NO:55), was used as a host strain for the chromosomal integration of the PCR fragments. The strain was constructed by transformation of E. coli strain MC1061 with the λ-Red recombinase expression plasmid, pKD46 (ampR). The λ-Red recombinase in pKD46 is comprised of three genes exo, bet, and gam expressed under the control of an arabinose-inducible promoter. Transformants were selected on 100 μg/mL of ampicillin LB plates at 30° C. For transformation, electroporation was performed using 5-10 μg of the purified PCR products carrying the kanamycin marker and phage T5 promoter. Approximately one-half of the cells transformed were spread on LB plates containing 25 μg/mL of kanamycin in order to select antibiotic-resistant transformants. After incubating the plate at 37° C. overnight, antibiotic-resistant transformants were selected as follows: 10 colonies of kan-PT5-dxs, 12 colonies of kan-PT5-idi, and 10 colonies of kan-PT5-ygbBygbP. PCR analysis was used to screen the selected kan-PT5 kanamycin-resistant transformants for integration of both the kanamycin selectable marker and the phage T5 promoter (PT5) in the correct location on the E. coli chromosome. For PCR, a colony was resuspended in 50 μL of PCR reaction mixture containing 200 μM dNTPs, 2.5 U AmpliTaq™ (Applied Biosytems), and 0.4 μM of specific primer pairs. Test primers were chosen to match sequences of the regions located in the kanamycin (5′-primer) and the early coding-region of each isoprenoid gene (3′-primer). The PCR reaction was performed as described above. Chromosomal integration of kan-PT5 upstream of each isoprenoid gene was confirmed by PCR analysis. The resultant E. coli strains carrying each kan-PT5-isoprenoid gene fusion on the chromosome were used for stacking multiple kan-PT5-isoprenoid gene fusions in parallel on the chromosome in a combinatorial approach as described in Examples 8-10. Example 8 Preparation of P1 Lysate Made from E. coli Kan-PT5-dxs, E. coli Kan-PT5-idi and E. coli Kan-PT5-ygbBygbP P1 lysates of the E. coli kan-PT5-dxs, E. coli kan-PT5-idi and E. coli kan-PT5-ygbBygbP strains were prepared by infecting a growing culture of bacteria with the P1 phage and allowing the cells to lyse (U.S. Ser. No. 10/735442). For P1 infection, each strain was inoculated in 4 mL LB medium with 25 μg/mL of kanamycin, grown at 37° C. overnight, and then sub-cultured with 1:100 dilution of an overnight culture in 10 mL LB medium containing 5 mM CaCl2. After 20-30 min of growth at 37° C., 107 P1vir phages were added. The cell-phage mixture was aerated for 2-3 hr at 37° C. until lysed, several drops of chloroform were added and the mixture vortexed for 30 sec and incubated for an additional 30 min at room temp. The mixture was then centrifuged for 10 min at 4500 rpm, and the supernatant transferred into a new tube to which several drops of chloroform were added. The lysates were stored at 4° C. Example 9 Construction of E. coli PT5-dXS PT5-idi Strain for Increased β-carotene Production In order to create a bacterial strain capable of increased carotenoid production, PT5-dXs and PT5-idi genes were chromosomally stacked into E. coli MG1655, capable of producing β-carotene, by P1 transduction in combination with the FLP site-specific recombinase. P1 lysate made from the E. coli kan-PT5-dxs strain was transduced into the recipient strain, E. coli MG1655 containing a β-carotene biosynthesis expression plasmid pPCB15 (camR)(SEQ ID NO:54). The plasmid pPCB15 (camR) contains the carotenoid biosynthesis gene cluster (crtEXYIB) from Pantoea Stewartii (ATCC no. 8199). The pPCB15 plasmid was constructed from ligation of Smal digested pSU18 (Bartolome et al., Gene, 102:75-78 (1991)) vector with a blunt-ended Pmel/Notl fragment carrying crtEXYIB from pPCB13 (Example 1). The E. coli MG1655 pPCB15 recipient cells were grown to mid-log phase (1−2×108 cells/mL) in 4 mL LB medium with 25 μg/mL of chloramphenicol at 37° C. Cells were spun down for 10 min at 4500 rpm and resuspended in 2 mL of 10 mM MgSO4 and 5 mM CaCl2. Recipient cells (100 μL) were mixed with 1 μL, 2 μL, 5 μL, or 10 μL of P1 lysate stock (107 pfu/μL) made from the E. coli kan-PT5-dxs strain and incubated at 30° C. for 30 min. The recipient cell-lysate mixture was spun down at 6500 rpm for 30 sec, resuspended in 100 μL of LB medium with 10 mM of sodium citrate, and incubated at 37° C. for 1 h. Cells were plated on LB plates containing both 25 μg/mL of kanamycin and 25 μg/mL of chloramphenicol in order to select for antibiotic-resistant transductants, and incubated at 37° C. for 1 or 2 days. Sixteen transductants were selected. To eliminate kanamycin selectable marker from the chromosome, a FLP recombinase expression plasmid pCP20 (ampR) (ATCC PTA-4455; Cherepanov and Wackernagel, Gene, 158:9-14 (1995)), which has a temperature-sensitive replication of origin, was transiently transformed into one of the kanamycin-resistant transductants by electroporation. Cells were spread onto LB agar containing 100 μg/mL of ampicillin and 25 μg/mL of chloramphenicol LB plates, and grown at 30° C. for 1 day. Colonies were picked and streaked on 25 μg/mL of chloramphenicol LB plates without ampicillin antibiotics and incubated at 43° C. overnight. Plasmid pCP20 has a temperature sensitive origin of replication and was cured from the host cells by culturing cells at 43° C. The colonies were tested for ampicillin and kanamycin sensitivity to test loss of pCP20 and kanamycin selectable marker by streaking colonies on 100 μg/mL of ampicillin LB plate or 25 μg/mL of kanamycin LB plate. Elimination of the kanamycin selectable marker from the E. coli chromosome was confirmed by PCR analysis (Example 7). The selected colonies were resuspended in 50 μL of PCR reaction mixture containing 200 μM dNTPs, 2.5 U AmpliTaq™ (Applied Biosytems), and 0.4 μM of different combination of specific primer pairs, T-kan (5′-ACCGGATATCACCACTTAT CTGCTC-3′; SEQ ID NO:28) and B-dxs (5′-TGGCMCAGTCGTAGCTCCTGGG TGG-3′; SEQ ID NO:29), T-T5 (5′-TMCCTATAAAAATAGGCGTATCACGAGG CCC-3′; SEQ ID NO:30) and B-dxs. Test primers were chosen to amplify regions located either in the kanamycin or the phage T5 promoter and the 5′ region of dxs gene. The PCR indicated the elimination of the kanamycin selectable marker from the E. coli chromosome. The presence of the phage T5 promoter fragment upstream of the dxs gene was confirmed based on the production of a PCR product of the expected size (229 bp). In this manner the E. coli PT5-dxs strain was constructed. In order to further stack kan-PT5-idi on the chromosome of E. coli PT5-dxs, P1 lysate made on E. coli kan-PT5-idi strain was transduced into the recipient strain, E. coli PT5-dxS, as described above. Approximately 450 kanamycin-resistance transductants were selected. After transduction, the kanamycin selectable marker was eliminated from the chromosome as described above, yielding E. coli PT5-dXs PT5-idi strain (WS100). For the E. coli PT5-dxs PT5-idi strain the correct integration of the is phage T5 promoter upstream of dxs and idi genes on the E. coli chromosome, and elimination of the kanamycin selectable marker were confirmed by PCR analysis. A colony of the E. coli PT5-dxs PT5-idi strain was tested by PCR with different combination of specific primer pairs, T-kan and B-dxs, T-T5 and B-dxs, T-kan and B-idi (CAGCCMCTGGAGMCGCGAGATGT; SEQ ID NO:31), and T-T5 and B-idi. Test primers were chosen to amplify regions located either in the kanamycin or the phage T5 promoter and the downstream region of the chromosomal integration site. The PCR reaction was performed as described above. The PCR results indicated the elimination of the kanamycin selectable marker from the E. coli chromosome. The chromosomal integration of the phage T5 promoter fragment upstream of the dxs and idi gene was confirmed based on the expected sizes of PCR products, 229 bp and 274 bp, respectively. Example 10 Production of Isorenieratene by E.coli Fermentation The plasmids pBHR-crt+ (kanR) and pTrcHis2-TOPO-crtU (ampR) were transformed into electrocompetent E. coli MG1655 PT5-dxs, PT5-idi cells (WS100), resulting in the E. coli strain DPR676 (ATCC # PTA-5136). The pBHR-crt+ plasmid was constructed as described in Example 5. DPR676 was pre-cultured for seeding a fermentor in 500 mL of 2× YT medium (10 g/L yeast extract, 16 g/L tryptone, 20 g/L glucose and 10 g/L NaCl) in a 2-L Erlenmeyer flask, containing 100 mg/mL ampicillin and 50 mg/mL kanamycin. The seed culture was started from a single colony on LB agar+100 mg/mL ampicillin and 50 mg/mL kanamycin. The seed culture was grown at 35° C. in a shaker at 300 rpm until ODXλ=550 reached 3.62. This initial culture was used to seed the fermentor. The following components were sterilized together in the fermentor vessel: 10 mL/L Modified Balch's Trace element solution, 5 g/L yeast extract, 0.2 g/L CaCl2.2H2O, 0.3 g/L ferric ammonium citrate, 2 g/L MgSO4.7H2O, 2 g/L citric acid, 7.5 g/L KH2PO4, 1.2 g/L sulfuric acid and 0.8 mL/L Mazu DF204 as an antifoam. After sterilization, the pH was raised to 6.8 with 40% NH4OH. The concentration of ampicillin was brought to 100 g/L and the concentration of kanamycin was brought to 50 mg/mL. Two hundred forty six grams of a 65% glucose solution was added post vessel sterilization to give a 20 g/L initial concentration in the fermentor. Modified Balch's Trace elements contained 4 g/L citric acid.H2O, 3 g/L MnSO4.H2O, 1 g/L NaCl, 0.1 g/L FeSO4.7H2O, 0.1 g/L ZnSO4.7H2O, 0.001 g/L CuSO4.5H2O, 0.001 g/L H3BO3, and 0.001 g/L NaMoO4.2H2O. After inoculation, the volume was 8 L and the glucose concentration was 20 g/L. A 10 L stirred tank fermentor was prepared with the medium described above. Eight hours into the fermentation run, when the glucose concentration fell below 1 g/L, a 10% fructose bolus was added at a rate of 20 mL/min until 1 L was added. The temperature was controlled at 37° C. and the pH was maintained at 6.8 with NH4OH and H3PO4. Back-pressure was manually controlled at 0.5 bar (7.5 psig; approximately 51.7 kPa)). The dissolved oxygen set point was 10%. Nine liters of cell culture was harvested and concentrated to 375 mL of cell slurry. A 1 mL volume of the cell slurry was used for HPLC analysis as described in Example 5. The results indicated that total extracted pigment contained 63% of isorenieratene, 16% of β-isorenieratene and 21% of β-carotene. A total of 31.4 mg of isorenieratene and 8 mg of β-isorenieratene were estimated to have been produced from the 9 liters of cell culture obtained in the fermentation. Example 11 Construction of E. coli PT5-dxs PT5-idi PT5-ygbBygbP Strain for Increased β-carotene Production In order to create a bacterial strain capable of increased carotenoid production, the PT5-ygbBygbP construct was further stacked into the E. coli PT5-dxs PT5-idi strain by P1 transduction in combination with the FLP recombination system (Examples 7-9). P1 lysate made using the E. coli kan-PT5-ygbBygbP strain was transduced into the recipient strain, E. coli kan-PT5-dxs kan-PT5-idi containing a β-carotene biosynthesis expression plasmid pPCB15 (camR), as described in Example 9. Twenty-one kanamycin-resistance transductants were selected. The kanamycin selectable marker was eliminated from the chromosome of the transductants using a FLP recombinase expression system, yielding E. coli strain PT5-dxs PT5-idi PT5-ygbBygbP. The correct chromosomal integration of the phage T5 promoter upstream of dxs, idi and ygbBP genes in E. coli PT5-dxs PT5-idi PT5-ygbBygbP and the elimination of the kanamycin selectable marker were confirmed by PCR analysis. A colony of the E. coli PT5-dxs PT5-idi PT5-ygbBygbP strain was tested by PCR with different combination of specific primer pairs, T-kan and B-dxs, T-T5 and B-dxs, T-kan and B-idi, T-T5 and B-idi, T-kan and B-ygb (5′-CCAGCAGCGCATGCACCGAGTGTTC-3′)(SEQ ID NO:32), and T-T5 and B-ygb. Test primers were chosen to amplify regions located either in the kanamycin or the phage T5 promoter and the downstream region of the chromosomal integration site. The PCR reaction was performed as described in Example 9. The PCR results indicated the elimination of the kanamycin selectable marker from the E. coli chromosome. The chromosomal integration of the phage T5 promoter fragment upstream of the dxs, idi, and ygbBygbP genes was confirmed based on the expected sizes of the PCR products, 229 bp, 274 bp, and 296 bp, respectively. Example 12 Chromosomal Integration of the P. stewartii crtE Gene in E.coli This example describes the chromosomal integration of P. stewartli crtE and crtIB genes into the region located at 81.2 min of E. coli chromosome by integration of P. stewartli crtE (SEQ ID NO:1) and P. stewartii crtIB (SEQ ID NOs:7 and 9). The crtE, crtI, and crtB genes encode geranylgeranyl pyrophosphate synthase, phytoene dehydrogenase, and phytoene synthase, respectively. These genes are involved in the carotenoid biosynthetic pathway (FIG. 2). The linear DNA fragment containing fused kanamycin selectable marker-phage T5 promoter is synthesized by PCR from pSUH5 (FIG. 5; SEQ ID NO:56) with primer pairs, Ti (crtE) (5′-AGCCGTCGCAGGAGGAACAACTCATATCATCATTGCGATCTCGACCG TCTTGAGCGATTGTGTAG-3′;SEQ ID NO:33) which contains an h10 homology arm (underlined, 45 bp) chosen to match a sequence in the inter-operon region located at 81.2 min of E. coli chromosome and a priming sequence (20 bp) and B1(crtE) (5′-TGMCGTGTTTTTTTGCGCAGACCGTCATAGTTMATTTCTCCTCTTTM TG-3′;SEQ ID NO:34) which contains an h11 homology arm (underlined, 29 bp) chosen to match a sequence in the downstream region of the crtE start codon and a priming sequence (22 bp)(FIG. 4). The linear DNA fragment containing P. stewartii crtE gene was synthesized by PCR from pPCB15 with primer pairs, T2(crtE) (5′-ACAGMTTCATTAAAGAGGAGAAATTMCTATGACGGTCTGCGCAAAA AAACACG-3′;SEQ ID NO:35) which contains an h8 homology arm (underlined, 30 bp) chosen to match a sequence in the 3′-end region of the fused kanamycin selectable marker-phage T5 promoter and a priming sequence (25 bp) and B2(crtE) (5′-AGMTGACCAGCTGGATGCATTATCTTTATTTGGATCATTGAGGGTTA ACTGACGGCAGCGAGTT-3′;SEQ ID NO:36) which contains an h12 homology arm (underlined, 45 bp) chosen to match a sequence in the inter-operon region located at 81.2 min of the E. coli chromosome and a priming sequence (20 bp). The underlined sequences illustrate each respective homology arm, while the remainder is the priming sequences for hybridization to complementary nucleotide sequences on the template DNA for the PCR reaction. The two resultant PCR fragments were the fused kanamycin selectable marker-phage T5 promoter containing the homology arms (h10 and h11) and the P. stewartii crtE gene containing the homology arms (h8 and h12) as illustrated in FIG. 4. The PCR amplification, purification, and electro-transformation were performed as described in Example 6 except that the transformation of the reporter plasmid pPCB1 5 into the E coli. strain was omitted. Both fused kanamycin marker-phage T5 promoter PCR products (5-10 μg) and the P. stewartii crtE PCR products (5-10 μg) were co-transformed into an E. coli host strain (MC1061) expressing the λ-Red recombinase system. Transformants were selected on 25 μg/mL of kanamycin LB plates at 37° C. After incubating the plate at 37 ° C. overnight, two kanR-resistant transformants were selected. Two kanR resistant transformants were PCR analyzed with T10 (5′-CCATGACCCTACATTGTGATCTATAG-3′;SEQ ID NO:37) and T13 (5′-GGMCCATTGAACTGGACCCTMCG-3′;SEQ ID NO:38) primer pair. PCR analysis was performed under same PCR reaction condition as described in Example 9. PCR testing with T10/T13 on two transformants exhibited the expected size of 2883 bp based on a 1% agarose gel, indicating the correct integration of the fused kanamycin selectable marker-phage T5 promoter DNA fragment along with P. stewartji crtE gene into the inter-operon region located at 81.2 min of E. coli chromosome, yielding E. coli kan-PT5-crtE (FIG. 4). Example 13 Chromosomal Integration of the P. stewartii crtl and crtB Genes in E.coli PT5-crtE for Construction of E. coli PT5-crtElB The linear DNA fragment containing the fused kanamycin selectable marker-phage T5 promoter-P. stewartii crtE gene was synthesized by PCR from the genomic DNA of E. coli PT5-crtE with primer pairs, T10 (SEQ ID NO:37) which contains a priming sequence (26 bp) corresponding to the 162 bases in the upstream region of the integration site of the fused kanamycin selectable marker-phage T5 promoter-crtE gene in E. coli and B1 (crtIB) (5′-TCCTCCAGCATTMGCCTGCCGTCGCCTTTTAACTGACGGCAGCG AGTTTTTTGTC-3′;SEQ ID NO:39) which contains an h13 homology arm (underlined, 29 bp) chosen to match sequences in the downstream region of the crtl start codon and a priming sequence (27 bp). The linear DNA fragment containing P. stewartii crtIB gene was synthesized by PCR from pPCB15 with primer pairs, T2(crtIB) (5′-TTTGACAAAAAACTCGCTGCCGTCAGTTAAAAGGCGACGGCAGGCTT AATGCTG-3′;SEQ ID NO:40) which contains a h14 homology arm (FIG. 4) (underlined, 30 bp) chosen to match a sequence in the 3′-end region of the fused kanamycin selectable marker-phage T5 promoter-crtE gene and a priming sequence (24 bp) and B2(crtIB) (5′-AGMTGACCAGCTGGATGCATTATCTTTATTTGGATCATTGAGGGCTA GATCGGGCGCTGCCAGA-3′;SEQ ID NO:41) which contains a h12 homology arm (underlined, 45 bp) (FIG. 4) chosen to match a sequence in the inter-operon region located at 81.2 min of the E. coli chromosome and a priming sequence (20 bp). The underlined sequences illustrate each respective homology arm, while the remainder is the priming sequences for hybridization to complementary nucleotide sequences on the template DNA for the PCR reaction. The two resultant PCR fragments were the fused kanamycin selectable marker-phage T5 promoter-P. stewartli crtE gene containing the homology region (162 bp) at the 5′-end and homology, arm (h13), and the P. stewartii crtIB genes containing the homology arms (h14 and h12) as illustrated in FIG. 4. The PCR amplification, purification, and electro-transformation were performed as described above except for the omission of transforming the host cell with the reporter plasmid, pPCB15. Both the fused kanamycin selectable marker-phage T5 promoter-P. stewartii crtE gene PCR products (5-10 μg) and the P. stewartii crtIB PCR products (5-10 μg) were co-transformed into an E. coli host cell expressing the λ-Red recombinase system by electroporation as previously described. Transformants were selected on 25 μg/mL of kanamycin LB plates at 37° C. After incubating the plate at 37° C. overnight, one kanR resistant transformant was selected. The selected kanR resistant transformant was PCR analyzed with different combinations of specific primer pairs, T10 and T2 (5′-CAGTCATAGCCGMTAGCCT-3′;SEQ ID NO:42), T2(T5) (5′-CGGTGCCCTGAATGMCTGC-3′;SEQ ID NO:43) and T12 (5′-CTAGATCGGGCGCTGCCAGAGATGA-3′;SEQ ID NO:44), TI 1(5′-ACACGTTCACCTTACTGGCATTTCG-3′;SEQ ID NO:45) and T13, and T10 and T13. Test primers were chosen to amplify sequences located either in the vicinity of the integration region of the kanamycin selectable marker-phage T5 promoter-crtE fragment or the crtIB genes. PCR analysis was performed under same PCR reaction condition as described in Example 9. PCR test with T10 and T2, T2(T5) and T12, T11 and T13, and T10 and T13 exhibited the expected sizes, 676 bp, 3472 bp, 3478 bp and 5288 bp on 1% agarose gel, respectively. The elimination of the kanamycin selectable marker was confirmed by PCR fragment analysis. PCR fragment analysis with primer pair T10 and T2 exhibited no product formation as expected. PCR analysis with primer pairs T2(T5) and T12, T11 and T13, and T10 and T13 exhibited the expected PCR product sizes of 3472 bp, 3478 bp, and 3895 bp on 1% agarose gel, respectively. The results indicated the correct integration of the fused kanamycin selectable marker-phage T5 promoter-P. stewartii crtE gene DNA fragment and P. stewartii crtIB genes into the inter-operon region located at 81.2 min of E. coli chromosome, yielding E. coli kan-PT5-crtElB. The functional expression of the constructed E. coli kan-PT5-crtElB was tested by the synthesis of lycopene based on the production of pink pigment. After extracting lycopene with acetone, the lycopene production by E. coli PT5-crtElB strain also was confirmed by measuring the spectra of lycopene with its characteristic λmax peaks at 444, 470, and 502 nm. Example 14 Construction of E. coli PT5-dxs PT5-idi PT5-vbB gbP PT5-CrtElB Strain The kan-PT5-P. stewartii crtElB was chromosomally stacked into E. coli PT5-dxs PT5-idi PT5- ygbBygbP strain. The kan PT5-P. stewartii crtElB was chromosomally integrated into E. coli PT5-dxs PT5-idi PT5-ygbBygbP strain by P1 transduction in combination. P1 lysate made on E. coli kan PT5-P. stewartii crtElB strain was transduced into the recipient strain, E. coli PT5-dxs PT5-idi PT5-ygbBygbP as described in Example 9. Sixteen kanamycin-resistance transductants were selected. The kanamycin selectable marker was eliminated from the chromosome of the transductants using a FLP recombinase expression system, yielding E. coli PT5-dxs PT5-idi PT5-ygbBygbP PT5-P. stewartil crtElB (WS156). The elimination of the kanamycin selectable marker was confirmed by PCR fragment analysis. PCR fragment analysis with primer pair T10 and T2 exhibited no product formation as expected. Example 15 Isolation and Characterization of Rhodococcus erythropolis Strain AN12 U.S. Ser. No. 10/292577 (corresponding to WO 03/044205) describes the isolation of strain AN12 of Rhodococcus erythropolis on the basis of being able to grow on aniline as the sole source of carbon and energy. Analysis of a 16S rRNA gene sequence indicated that strain AN12 was related to high G+C gram positive bacteria belonging to the genus Rhodococcus. Briefly, bacteria that grew on aniline were isolated from an enrichment culture. The enrichment culture was established by inoculating 1 mL of activated sludge into 10 mL of S12 medium (10 mM ammonium sulfate, 50 mM potassium phosphate buffer (pH 7.0), 2 mM MgCl2, 0.7 mM CaCl2, 50 μM MnCl2, 1 μM FeCl3, 1 μM ZnCl3, 1.72 μM CuSO4, 2.53 μM CoCl2, 2.42 μM Na2MoO2, and 0.0001% FeSO4) in a 125 mL screw cap Erlenmeyer flask. The activated sludge was obtained from a wastewater treatment facility. The enrichment culture was supplemented with 100 ppm aniline added directly to the culture medium and was incubated at 25° C. with reciprocal shaking. The enrichment culture was maintained by adding 100 ppm of aniline every 2-3 days. The culture was diluted every 14 days by replacing 9.9 mL of the culture with the same volume of S12 medium. Bacteria that utilized aniline as a sole source of carbon and energy were isolated by spreading samples of the enrichment culture onto S12 agar. Aniline (5 μL) was placed on the interior of each petri dish lid. The petri dishes were sealed with parafilm and incubated upside down at room temperature (approximately 25° C.). Representative bacterial colonies were then tested for the ability to use aniline as a sole source of carbon and energy. Colonies were transferred from the original S12 agar plates used for initial isolation to new S12 agar plates and supplied with aniline on the interior of each petri dish lid. The petri dishes were sealed with parafilm and incubated upside down at room temperature (approximately 25° C.). The 16S rRNA genes of each isolate were amplified by PCR and analyzed as follows. Each isolate was grown on R2A agar (Difco Laboratories, Bedford, Mass.). Several colonies from a culture plate were suspended in 100 μl of water. The mixture was frozen and then thawed once. The 16S rRNA gene sequences were amplified by PCR using a commercial kit according to the manufacturer's instructions (Perkin Elmer) with primers HK12 (5′-GAGTTTGATCCTGGCTCAG-3′) (SEQ ID NO:46) and HK13 (5′-TACCTTGTTACGACTT-3′) (SEQ ID NO:47). PCR was performed in a Perkin Elmer GeneAmp 9600 (Norwalk, Conn.). The samples were incubated for 5 min at 94° C. and then cycled 35 times at 94° C. for 30 sec, 55° C. for 1 min, and 72° C. for 1 min. The amplified 16S rRNA genes were purified using a commercial kit according to the manufacturer's instructions (QIAquick PCR Purification Kit, Qiagen, Valencia, Calif.) and sequenced on an automated ABI sequencer. The sequencing reactions were initiated with primers HK12, HK13, and HK14 (5′-GTGCCAGCAGYMGCGGT-3′) (SEQ ID NO:48, where Y═C or T, M═A or C). The 16S rRNA gene sequence of each isolate was used as the query sequence for a BLAST search (Altschul et al., Nucleic Acids Res., 25:3389-3402(1997)) of GenBank® for similar sequences. A 16S rRNA gene of strain AN12 was sequenced and compared to other 16S rRNA sequences in the GenBank® sequence database. The 16S rRNA gene sequence from strain AN12 was at least 98% similar to the 16S rRNA gene sequences of high G+C gram positive bacteria belonging to the genus Rhodococcus. Example 16 Identification of Lycoiene Cyclases from Rhodococcus and Deinococcus The ORF for crtL was identified by conducting BLAST (Basic Local Alignment Search Tool; Altschul, S. F., et al., J. Mol. Biol., 215:403-410 (1993)) searches for similarity to sequences contained in the BLAST “nr” database (comprising all non-redundant (nr) GenBank® CDS translations, sequences derived from the 3-dimensional structure Brookhaven Protein Data Bank, the SWISS-PROT protein sequence database, EMBL, and DDBJ databases). The genomic sequence of Rhodococcus erythropolis AN12 was analyzed for similarity to all publicly available DNA sequences contained in the “nr” database using the BLASTN algorithm provided by the National Center for Biotechnology Information (NCBI). The DNA sequences were translated in all reading frames and compared for similarity to all publicly available protein sequences contained in the “nr” database using the BLASTX algorithm (Altschul et al., Nucleic Acid Res., 25:3389-3402 (1997)) provided by the NCBI. Results from the BLAST analysis indicated that the lycopene β-cyclase from Rhodococcus erythropolis strain AN12 (SEQ ID NOs:49 and 50) shared homology to a putative carotenoid lycopene β-cyclase DR0801 (GenBank® ID MF10377.1) from Deinococcus radiodurans strain R1 (percent identity=31%, percent similarity=45%, E-value 2e-37) and other CrtL-type of lycopene β-cyclases from plants (U.S. Ser. No. 10/292577). Example 17 Production of Chlorobactene in E. coli using the Optimized CrtU To demonstrate that the optimized crtU could be used in E. coli to synthesize other aryl-carotenoids in addition to isorenieratene, Applicants chose to synthesize chlorobactene by expressing the optimized crtU in E. coli producing γ-carotene. E. coli strains had been constructed that contained a single copy of the carotenoid pathway gene(s) expressed under phage T5 promoter on the chromosome. E.coli PT5-dxs, PT5-idi, PT5-ygbBygbP, PT5-crtElB (WS1 56) showed darker pink color and produced lycopene. The γ-carotene producing strain was constructed by expressing an asymmetric lycopene cyclase, crtL (SEQ ID NOs:49 and 50) in WS156 strain. The crtL gene was PCR amplified from genomic DNA of Rhodococcus erythropolis AN12, using forward primer crtL(an12)_F (5′-gaattcaggaggaataaaccatgagcacactcgactcctcc-3′;SEQ ID NO:51) and reverse primer crtL(an12)_R (5′-caattqtcaccggaaaaacggcgc-3′;SEQ ID NO:52). Underlined part in the primers is EcoRI or Mfe I site and the bolded sequence indicates an artificial ribosome binding site. The 1157 bp PCR product was cloned in the pTrcHis2-TOPO cloning vector, resulted pDCQ185. The ˜1.2 kb EcoR I fragment from pDCQ185 containing the crtL gene was ligated into the EcoR I site in pBHR1 vector (MoBiTec, Göttingen, Germany) to create pDCQ186, in which the crtL is expressed under the control of the chloramphenicol resistant gene promoter on the vector. WS156KanS cells were transformed with pDCQ186. Transformants were grown in LB (Luria Broth) or TB (Terrific Broth) medium with 50 μg/mL kanamycin at 37° C. for 1 day and cells were harvested by centrifugation. Carotenoids were extracted from the cell pellets three times, each with 10 mL of acetone for 15 min at room temperature. The extracted pigments were dried under nitrogen and dissolved in 1 mL acetone. Each sample of 0.1 mL was used for HPLC analysis as described previously. The major pigment comprising 96% of the total carotenoids eluted at 13.6 min with absorption spectrum of (439), 463, 492 nm, which is characteristic of γ-carotene. The crtU expressing plasmid pTrcHis2-TOPO-crtU was transformed into they-carotene producing strain WS156Kans (pDCQ186). The transformants were grown at 37° C. for 1 day in 25 mL TB with 50 μg/mL kanamycin and 100 μg/mL ampicillin. Cells were harvested by centrifugation and carotenoids were extracted and analyzed by HPLC. A new pigment peak eluted at 10.7 min was observed which has the absorption spectrum of 437, 461, and 490 nm. This is identical to the characteristics of chlorobactene previously produced from Rhodococcus. The chlorobactene pigment comprised 10% of the total carotenoids from this strain. | <SOH> BACKGROUND OF THE INVENTION <EOH>Carotenoids are pigments that are ubiquitous throughout nature and synthesized by all photosynthetic organisms, and in some heterotrophic growing bacteria and fungi. Carotenoids provide color for flowers, vegetables, insects, fish, and birds. Colors range from yellow to red with variations of brown and purple. As precursors of vitamin A, carotenoids are fundamental components in our diet and they play an important role in human health. Industrial uses of carotenoids include pharmaceuticals, food supplements, animal feed additives, and colorants in cosmetics, to mention a few. Because animals are unable to synthesize carotenoids de novo, they must obtain them by dietary means. Thus, manipulation of carotenoid production and composition in bacteria can provide new or improved sources for carotenoids. Carotenoids come in many different forms and chemical structures. Most naturally occurring carotenoids are hydrophobic tetraterpenoids containing a C 40 methyl-branched hydrocarbon backbone derived from successive condensation of eight C 5 isoprene units (IPP). In addition, novel carotenoids with longer or shorter backbones occur in some species of nonphotosynthetic bacteria. Carotenoids may be acyclic, monocyclic, or bicyclic depending on whether the ends of the hydrocarbon backbones have been cyclized to yield aliphatic or cyclic ring structures (G. Armstrong, (1999) In Comprehensive Natural Products Chemistry , Elsevier Press, volume 2, pp 321-352). Carotenoid biosynthesis starts with the isoprenoid pathway to generate the C5 isoprene unit, isopentenyl pyrophosphate (IPP). IPP is then condensed with its isomer dimethylallyl pyrophosphate (DMAPP) to generate the C10 geranyl pyrophosphate (GPP) which is then elongated to form the C15 farnesyl pyrophosphate (FPP). FPP synthesis is common in both carotenogenic and non-carotenogenic bacteria. Additional enzymes in the carotenoid pathway are able to then generate carotenoid pigments from the FPP precursor, segregating into two categories: (i) carotene backbone synthesis enzymes and (ii) subsequent modification enzymes. The backbone synthesis enzymes include geranyl geranyl pyrophosphate synthase, phytoene synthase, phytoene dehydrogenase and lycopene cyclase, etc. The modification enzymes include ketolases, hydroxylases, dehydratases, glycosylases, etc. It is known that β-carotene can be converted to isorenieratene, an aromatic carotenoid, by a CrtU carotene desaturase. The crtU gene, encoding the carotene desaturase, has been identified in a few actinomycetes including Streptomyces, Mycobacterium and Brevibacterium (Krugel et al., Biochimica et Biophysica Acta, 1439: 57-64 (1999); Krubasik and Sandmann, Mol Gen Genet 263: 423432 (2000); and Viveiros et al., FEMS Microbiol Lett, 187: 95-101 (2000)). Another aryl-carotene, chlorobactene, was reported in photosynthetic green bacteria (Liaaen-Jensen et al., Acta Chem. Scand 18: 1703-1718 (1964); Takaichi et al., Arch Microbiol, 168: 270-276 (1997)). Recent genomic sequencing of Chlorobium tepidum identified a putative carotene desaturase gene (Eisen et al., PNAS USA, 99: 9509-9514 (2002), which might be responsible for the synthesis of the native chlorobactene and derivatives. However, function of the putative carotene desaturase gene from Chlorobium has not yet been determined. It is likely that the CrtU from actinomycetes might also act on other substrates in addition to β-carotene to produce a variety of aryl-carotenoids, such as converting γ-carotene to chlorobactene. Schumann et al. ( Mol Gen Genet, 252: 658-666 (1996)) reported difficulty in attempting to express crtU in heterologous hosts. However, Lee et al. ( Chem Biol 10(5): 453-462 (2003)) recently reported successful expression of the Brevibacterium linens crtU (DSMZ 20426) in E. coli using a pUC-derived expression vector. Lee et al. were able to detect the production of isorenieratene (in cells engineered to produce β-carotene) and didehydro-β-θ-carotene (in cells engineered to produce torulene). Lee et al. did not report the levels of aromatic carotenoids produced. It is likely the level was low since a low copy number pACYC-base plasmid was used to produce β-carotene precursor in a non-engineered E. coli host. Production of commercially-significant amounts of aryl carotenoids has not been reported in the literature. Expressing genes from gram positive bacteria (with high G+C content) in E. coli is known to be often difficult. Low yields of protein in heterologous expression systems can been attributed to differences in codon usage. Difficulties in expressing heterologous genes in a host strain are generally due to an extremely rare codon used by host strain and correlates with low levels of its corresponding tRNA. The inability to adequately express CrtU carotene desaturases in a gram-negative host for production of aryl carotenoids at commercially-useful levels presents a significant hurdle to the synthesis of a variety of aryl-carotenoids by genetic engineering. Furthermore, natural aryl-carotenoids are always present as mixtures of the aryl-carotenoid with their precursors or derivatives (Kohl et al., Phytochemistiy, 22: 207-213 (1983); Takaichi et al., supra). Production of a pure aryl-carotenoid requires the ability to efficiently express the carotene desaturase in an industrially-useful heterologous host, such as E. coli. The problem to be solved is to express a functional carotene desaturase (crtU) gene for the production of aryl-carotenoids in a gram-negative production host at commercially-significant concentrations. Applicants have solved the stated problem by isolating the crtU gene from Brevibacterium linens and expressing an optimized version of this gene in an Escherichia coli strain engineered to produce high levels of carotenoids. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides methods for the expression of carotene desaturase genes and proteins in gram negative host cells for the conversion of cyclic carotenoids to the corresponding aryl compound. Accordingly the invention provides a method for the production of aryl carotenoid compounds comprising: (a) providing a gram negative host cell which comprises a cyclic carotenoid having at least one u-ionone ring; (b) transforming the gram negative host cell of (a) with a foreign gene encoding a carotene desaturase, said gene being codon optimized for expression in the gram negative host cell; and (c) growing the transformed gram negative host cell of (b) under conditions whereby an aryl carotenoid is produced. In similar fashion the invention provides a method of regulating aryl carotenoid biosynthesis in an E. coli host comprising: (a) introducing into an E. coli a carotene desaturase gene having the nucleic acid sequence selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53; and (b) growing the E. coli of (a) under conditions whereby the carotene desaturase gene is expressed and aryl carotenoid biosynthesis is regulated. In a preferred embodiment the invention provides a method for the production of isorenieratene comprising: (a) providing a gram negative host cell which comprises β-carotene; (b) transforming the gram negative host cell of (a) with a gene encoding a carotene desaturase, said gene being codon optimized for expression in said gram negative host; and (c) growing the transformed gram negative host cell of (b) under conditions whereby an aryl carotenoid is produced. In an alternate embodiment the invention provides a method for the production of chlorobactene comprising: (a) providing a gram negative host cell which comprises γ-carotene; (b) transforming the gram negative host cell of (a) with a gene encoding a carotene desaturase, said gene being codon optimized for expression in said gram negative host; and (c) growing the gram negative transformed host cell of (b) under conditions whereby chlorobactene is produced. In an alternate embodiment the invention provides an E. coli codon optimized carotene desaturase gene selected from the group consisting of SEQ ID NO:18 and SEQ ID NO:53. | 20040708 | 20061107 | 20050127 | 94056.0 | 0 | GEBREYESUS, KAGNEW H | PRODUCTION OR AROMATIC CAROTENOIDS IN GRAM NEGATIVE BACTERIA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,886,964 | ACCEPTED | Ejection control of quality-enhancing ink | A printing control method of generating dot data representing a state of dot formation at each pixel in a printed image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit. This process includes a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area. | 1. A printing control method of generating print data to be supplied to a print unit to print, the print unit forming dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material, the printing control method comprising: the dot data-generating step of generating dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit, wherein the step includes a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area with regard to at least one identical pixel value of the image data, wherein the quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink; the peripheral area is set at end portions of the printing medium; and the center area is set in a central portion of the printing medium. 2. The printing control method in accordance with claim 1, wherein the dot data-generating step includes the step of setting the quality-enhancing ink dot-recording rate equal to zero for the pixels belonging to the peripheral area. 3. The printing control method in accordance with claim 1, wherein the quality-enhancing ink is a picture quality-enhancing ink for enhancing a picture quality of the printed image. 4. The printing control method in accordance with claim 1, wherein the printing medium is a roll paper, and the peripheral area is located only in end portions of the roll paper parallel to a sub-scanning direction. 5. The printing control method in accordance with claim 1, wherein the dot data-generating step comprises the steps of: a color conversion step of converting color in each pixel of the image data into a tone value, the tone value being for expressing the color with the at least one colored ink and the quality-enhancing ink available in the print unit; and a color-quantizing step of generating the dot data representing a state of dot formation at each pixel, in response to the converted tone value with regard to each pixel of the image data, wherein the color conversion step includes a processing mode configured to make a quality-enhancing ink tone value for pixels belonging to the peripheral area lower than the quality-enhancing ink tone value for pixels belonging to the center area with regard to at least one identical pixel value of the image data, wherein the quality-enhancing ink tone value is the tone value of the quality-enhancing ink. 6. The printing control method in accordance with claim 5, wherein the color conversion step comprises the steps of: a table-reading step of reading a peripheral area color conversion table and a center area color conversion table, the peripheral area color conversion table being a color conversion table applied for the pixels belonging to the peripheral area, the center area color conversion table being a color conversion table applied for the pixels belonging to the center area; and a table selection step of selecting the peripheral area color conversion table for the pixels belonging to the peripheral area, while selecting the center area color conversion table for the pixels belonging to the center area. 7. The printing control method in accordance with claim 6, wherein a transition area is further set between the peripheral area and the center area, wherein the color-quantizing step comprises the step of interpolating with the peripheral area color conversion table and the center area color conversion table to determine the quality-enhancing ink tone value in the transition area. 8. The printing control method in accordance with claim 6, wherein a transition area is further set between the peripheral area and the center area, wherein the table-reading step comprise the step of further reading a transition area color conversion table, the transition area color conversion table being a color conversion table applied for the pixels belonging to the transition area, the table selection step includes the step of selecting the transition area color conversion table for the pixels belonging to the transition area, the transition area color conversion table is configured such that the quality-enhancing ink tone value for the transition area is higher than the peripheral area color conversion table but lower than the center area color conversion table with regard to at least one identical pixel value prior to the color conversion. 9. The printing control method in accordance with claim 8, wherein the table-reading step includes the step of reading multiple color conversion tables for the transition area, the multiple color conversion tables having different quality-enhancing ink tone values with regard to at least one identical pixel value prior to the color conversion, and the table selection step includes the step of selecting a color conversion table for transition area having higher quality-enhancing ink tone values to be applied to pixels in closer position to the center area within the transition area, wherein the multiple color conversion tables have quality-enhancing ink tone values higher than the peripheral area color conversion table but lower than the center area color conversion table with regard to at least one identical pixel value prior to the color conversion. 10. The printing control method in accordance with claim 7, wherein the color conversion step includes the step of converting by each main scanning line that is consecutive pixels aligned in a main scanning direction, and the interpolating step of interpolating with the peripheral area color conversion tale and the center area color conversion table to determine the quality-enhancing ink tone values in the transition area, if the color conversion process for one main scanning line needs more than one color conversion table for the color conversion. 11. The printing control method in accordance with claim 7, wherein the color conversion step includes the step of converting by each sub-scanning line that is consecutive pixels aligned in a sub-scanning direction, and the interpolating step of interpolating with the peripheral area color conversion tale and the center area color conversion table to determine the quality-enhancing ink tone values in the transition area, if the color conversion process for one sub-scanning line needs more than one color conversion table for the color conversion. 12. A printing method of forming dots on a printing medium to print an image, the printing method comprising the steps of: (a) providing a print unit configured to form the dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material; and (b) generating dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit, wherein the step (b) includes a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area with regard to at least one identical pixel value of the image data, wherein the quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink; the peripheral area is set at end portions of the printing medium; the center area is set in a central portion of the printing medium. 13. A printing method of forming dots on a printing medium to print an image, the printing method comprising the steps of: (a) providing a print unit configured to form the dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material; and (b) generating dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit, wherein the print unit a has an operation mode to restrict ejection of the quality-enhancing ink in the pixels belonging to the peripheral area, wherein the quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink; the peripheral area is set at end portions of the printing medium; the center area is set in a central portion of the printing medium. 14. A printing apparatus for forming dots on a printing medium to print an image, the printing apparatus comprising: a print unit configured to form the dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material; and a dot data generator configured to generate dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit, wherein the dot data generator includes a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area with regard to at least one identical pixel value of the image data, wherein the quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink; the peripheral area is set at end portions of the printing medium; the center area is set in a central portion of the printing medium. 15. A printing apparatus for forming dots on a printing medium to print an image, the printing apparatus comprising: a print unit configured to form the dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material; and a dot data generator configured to generate dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit, wherein the print unit a has an operation mode to restrict ejection of the quality-enhancing ink in the pixels belonging to the peripheral area, wherein the quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink; the peripheral area is set at end portions of the printing medium; the center area is set in a central portion of the printing medium. 16. A printing control apparatus for generating print data to be supplied to a print unit to print, the print unit forming dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material, the printing control apparatus comprising: a dot data generator configured to generate dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit, wherein the dot data generator has a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area with regard to at least one identical pixel value of the image data, wherein the quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink; the peripheral area is set at end portions of the printing medium; and the center area is set in a central portion of the printing medium. 17. A computer program product for causing a computer to generate print data to be supplied to a print unit to print, the print unit forming dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material, wherein, the computer program product comprising: a computer readable medium; and a computer program stored on the computer readable medium, the computer program comprising: a program for causing the computer to generate dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit, wherein the program includes a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area with regard to at least one identical pixel value of the image data, wherein the quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink; the peripheral area is set at end portions of the printing medium; and the center area is set in a central portion of the printing medium. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing technique that ejects ink droplets of multiple types of inks on a printing medium to print an image. 2. Description of the Related Art Printers that eject inks from nozzles on a print head have widely been used as an output unit of the computer. There is a known printer that is capable of printing an image to respective ends of printing paper (see Japanese Patent Laid-Open Gazette No. 2002-103586). One proposed method to attain such margin-free printing uses ink absorption materials set in grooves of a platen to absorb ink ejected outside the printing paper. Quality-enhancing ink is used to enhance the quality of printed materials, for example, enhancement of color development, water resistance, and light resistance and reduction of a variation in gloss. The Quality-enhancing ink may, however, be dried up on the surface of the ink absorption materials and interfere with smooth absorption of colored inks into the ink absorption materials. The Quality-enhancing ink is used not for coloring but for improvement of the quality of the printed materials. Partial absence of the Quality-enhancing ink thus does not significantly deteriorate the quality, additionally the deterioration of the quality is rather inconspicuous at the ends of the printed materials. SUMMARY OF THE INVENTION The object of the invention is to provide a printing technique that prints an image to respective ends of a printing medium, while reducing ejection of ink droplets of quality-enhancing ink outside the printing medium. In order to attain the above objects of the present invention, there is provided a printing control method of generating print data to be supplied to a print unit to print. The print unit forms dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material. The printing control method comprises the dot data-generating step of generating dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit. The step includes a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area with regard to at least one identical pixel value of the image data. The quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink. The peripheral area is set at end portions of the printing medium. The center area is set in a central portion of the printing medium. The printing method of the invention is capable of making the quality-enhancing ink dot-recording rate for the pixels belonging to the peripheral area lower than the quality-enhancing ink dot recording rate for the pixels belonging to the center area. This arrangement ensures printing to the respective ends of the printing medium, while reducing ejection of ink droplets of the quality-enhancing ink outside the printing medium. In the specification hereof, the terminology “printed material” represents a print obtained by ejection of ink droplets of the colored ink and the quality-enhancing ink on the printing medium. The terminology “quality-enhancing ink” represents ink used for enhancing the quality of printed materials, for example, enhancement of color development, water resistance, and light resistance and reduction of a variation in gloss. The present invention can be realized in various forms such as a method and apparatus for printing, a method and apparatus for printing control, and a computer-program product implementing the above scheme. These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram schematically illustrating the configuration of a printing system in one embodiment of the invention; FIG. 2 schematically illustrates the structure of a color printer included in the printing system; FIG. 3 is a block diagram showing the internal structure of the color printer including a control circuit; FIGS. 4(a), 4(b), 4(c) show printing processes on respective ends of printing paper P; FIG. 5 shows an arrangement of nozzles Nz on the bottom face of a print head; FIG. 6 is a flowchart showing a print data generation routine executed in the first embodiment; FIG. 7 is a plan view showing division of the area of resolution-converted image data relative to the printing paper P; FIG. 8 shows color conversion tables applied to determine dot level data of three variable-size dots, large-size, medium-size, and small-size dots; FIGS. 9(a), 9(b) are graphs showing a variation in ejection volume of a quality-enhancing ink against the ejection volume of a colored ink in a center area; FIGS. 10(a), 10(b) are plan views showing division of the area of image data relative to the printing paper P in the second embodiment of the invention; FIGS. 11(a), 11(b) are plan views showing division of the area of image data relative to the printing paper P in the third embodiment of the invention; FIGS. 12(a), 12(b) are plan views showing division of the area of image data relative to the printing paper P in the fourth embodiment of the invention; and FIG. 13 is a plan view showing division of the area of image data relative to printing paper R in a modified example. DESCRIPTION OF THE PREFERRED EMBODIMENTS Some modes of carrying out the invention are discussed below in the following sequence as preferred embodiments with reference to the accompanied drawings: A. Configuration of System B. Print Data Generation Process of First Embodiment C. Print Data Generation Process of Second Embodiment D. Print Data Generation Process of Third Embodiment E. Print Data Generation Process of Fourth Embodiment F. Modifications A. Configuration of System FIG. 1 is a block diagram schematically illustrating the configuration of a printing system in one embodiment of the invention. This printing system includes a computer 90 functioning as a printing control apparatus and a color printer 20 functioning as a print unit. The combination of the color printer 20 with the computer 90 is regarded as a “printing apparatus” in the broad sense. Application program 95 operates on computer 90 under a specific operating system. A video driver 91 and a printer driver 96 are incorporated in the operating system. The application program 95 outputs image data, which goes through a series of image processing in the printer driver 96 and is given as print data PD to the color printer 20. The application program 95 also outputs image data to display a processed image on a CRT 21 via the video driver 91. The printer driver 96 includes a resolution conversion module 97, a color conversion module 98, a color-quantizing module 99, a print data generation module 100, multiple color conversion tables LUT, and a dot rate table DT. The functions of these constituents will be discussed later. The printer driver 96 is equivalent to a program functioning to generate the print data PD. The program of attaining the functions of the printer driver 96 is supplied in the form recorded in a computer readable recording medium. Typical examples of such computer readable recording medium include flexible disks, CD-ROMs, magneto-optic disks, IC cards, ROM cartridges, punched cards, prints with barcodes or other codes printed thereon, internal storage devices (memories like RAM and ROM) and external storage devices of the computer, and a diversity of other computer readable media. FIG. 2 schematically illustrates the structure of the color printer 20. The color printer 20 has a sub-scan drive unit that activates a paper feed motor 22 to feed a sheet of printing paper P in a sub-scanning direction, a main scan drive unit that activates a carriage motor 24 to move a carriage 30 back and forth in an axial direction of a paper feed roller 25 (in a main scanning direction), a head drive mechanism that drives a print head unit 60 (also called ‘print head assembly’) mounted on the carriage 30 to control ink ejection and dot formation, and a control circuit 40 that transmits signals to and from the paper feed motor 22, the carriage motor 24, the print head unit 60, and an operation panel 32. The control circuit 40 is connected to the computer 90 via a connector 56. The sub-scan drive unit for feeding the printing paper P has a non-illustrated gear train to transmit rotation of the paper feed motor 22 to the paper feed roller 25. The main scan drive unit for reciprocating the carriage 30 has a sliding shaft 34 that is arranged in parallel with the axis of the paper feed roller 25 to hold the carriage 30 in a slidable manner, a pulley 38 that supports an endless drive belt 36 spanned between the carriage motor 24 and the pulley 38, and a position sensor 39 that detects the position of the origin of the carriage 30. FIG. 3 is a block diagram showing the internal structure of the color printer 20 including the control circuit 40. The control circuit 40 is constructed as an arithmetic logic circuit, which includes a CPU 41, a programmable ROM (P-ROM) 43, a RAM 44, and a character generator (CG) 45 storing dot matrixes of characters. The control circuit 40 also has an exclusive I/F circuit 50 functioning as an interface to external motors and other elements, a head drive circuit 52 that is connected with the exclusive I/F circuit 50 and drives the print head unit 60 for ink ejection, and a motor drive circuit 54 that is connected with the exclusive I/F circuit 50 and drives the paper feed motor 22 and the carriage motor 24. The exclusive I/F circuit 50 has a built-in parallel interface circuit and receives the print data PD from the computer 90 via the connector 56. The color printer 20 carries out printing according to the received print data PD. The RAM 44 works as a buffer memory to temporarily store raster data. The print head unit 60 has a print head 28 and supports ink cartridges detachably attached thereto. The print head unit 60 is attached and detached as an integral unit to and from the color printer 20. Namely replacement of the print head 28 requires replacement of the whole print head unit 60. FIGS. 4(a), 4(b), 4(c) show printing processes on respective ends of the printing paper P. Two nozzles #1 and #2 on the print head 28 are located above the opening of a downstream groove 126r, and two other nozzles #7 and #8 are located above the opening of an upstream groove 126f. Other nozzles #3, #4, #5, and #6 are located above a platen frame 125. As shown in FIG. 4(b), each side end Ps of the printing paper P is positioned above the opening of a side groove 126s. Ink absorption materials 127r, 127f, and 127s for absorbing ink are respectively set in the downstream groove 126r, the upstream groove 126f, and the side grooves 126s. The two pairs of nozzles #1 and #2, #7 and #8 are respectively located above the opening of the downstream groove 126r and above the opening of the upstream groove 126f. This structure protects the platen frame 125 and a roller 25d from stains of ink that is ejected from the nozzles #1, #2, #7, and #8 before the printing paper P fed by the sub-scan feed reaches the respective nozzles #1, #2, #7, and #8 or after the printing paper P passes through the respective nozzles #1, #2, #7, and #8. The sub-scan feed of the printing paper P is implemented by at least either a pair of upstream paper feed rollers 25a and 25b or a pair of downstream paper feed rollers 25c and 25d. The upstream paper feed rollers 25a and 25b and the downstream paper feed rollers 25c and 25d are equivalent to the paper feed roller 25 mentioned previously. FIG. 4(a) shows a printing process on a front end Pf of the printing paper P. The two nozzles #1 and #2 start ink ejection a little before the front end Pf of the printing paper P reaches the effective recording positions of these nozzles #1 and #2. Even in the presence of some paper feed error, this arrangement does not make any undesirable margin but ensures printing to the front end Pf of the printing paper P, while protecting the platen frame 125 and the roller 25d from stains of ink. FIG. 4(b) shows a printing process on side ends Ps of the printing paper P. Each side end Ps of the printing paper P is located above the opening of the side groove 126s. This arrangement does not make any undesirable margin but ensures printing to the side ends Ps of the printing paper P. FIG. 4(c) shows a printing process on a rear end Pr of the printing paper P. The two nozzles #7 and #8 stop ink ejection after the rear end Pr of the printing paper P passes through the effective recording positions of these nozzles #7 and #8. Even in the presence of some paper feed error, this arrangement does not make any undesirable margin but ensures printing to the rear end Pr of the printing paper P, while protecting the platen frame 125 and the roller 25d from stains of ink. FIG. 5 shows an arrangement of nozzles Nz on the bottom face of the print head 28. Nozzle arrays for black ink K, cyan ink C, light cyan ink LC, magenta ink M, light magenta ink LM, yellow ink Y, and quality-enhancing ink CL are formed on the bottom face of the print head 28. The available inks other than the quality-enhancing ink CL are not restricted to these six inks K, C, LC, M, LM, and Y but may be selected arbitrarily according to the desired picture quality of printed material images. For example, the four inks K, C, M, and Y may be used, or only the black ink K may be used. Dark yellow ink having the lower lightness than the yellow ink Y, gray ink having the higher lightness than the black ink K, blue ink, red ink, and green ink may be used in some combinations. In the specification hereof, ink containing any of such color material is called ‘colored ink’. The quality-enhancing ink CL may be transparent and colorless ink having similar gloss to the other inks and enhancing the color development of the other inks. The quality-enhancing ink CL may be ink disclosed in Japanese Patent Laid-Open Gazette No. 8-60059. The quality-enhancing ink CL functions to reduce the variation in gloss and enhance the color development, thus improving the picture quality of the printed material. The quality-enhancing ink CL may otherwise be ink for enhancing the water resistance or the light resistance to improve the water resistance or the light resistance of printed material. In the color printer 20 having the hardware structure discussed above, while the printing paper P is fed by the paper feed motor 22, the carriage 30 is moved back and forth by means of the carriage motor 24 and simultaneously piezoelectric elements on the print head 28 are actuated to eject ink droplets of the respective color inks and form ink dots of variable sizes (large, medium, small). This gives a multi-color, multi-tone image on the printing paper P. B. Print Data Generation Process of First Embodiment FIG. 6 is a flowchart showing a print data generation routine executed in the first embodiment. The print data generation routine is executed by the computer 90 to generate print data PD, which is given to the color printer 20. A margin-free print mode is set for printing to the respective ends of the printing paper P. At step S100, the printer driver 96 (see FIG. 1) inputs image data from the application program 95. Input of the image data is triggered by a printing instruction from the application program 95. In this embodiment, the input image data is RGB image data. At step S200, the resolution conversion module 97 converts the resolution (the number of pixels per unit length) of the input RGB image data into a predetermined resolution. The predetermined resolution is set to assure a printable area to the respective ends of the printing paper P. The resolution conversion module 97 divides the area of the image data into a “center area” and a “peripheral area”. The center area is set such that restriction of ink ejection to the center area prevents any ink droplet from being flown outside the printing paper P, regardless of any potential error in sub-scan feed of the printing paper P or any potential flight error of ink droplets. The peripheral area is non-center area in the area of the image data. FIG. 7 is a plan view showing division of the area of the resolution-converted image data relative to the printing paper P. As clearly shown in FIG. 7, the whole area of the image data is set wider than the whole area of the printing paper P. Such setting enables ink droplets of each colored ink to be flown to the respective ends of the printing paper P, regardless of any potential error in sub-scan feed of the printing paper P or any potential flight error of ink droplets. The area of the image data is, however, limited to a specific range that effectively prevents ink droplets of each colored ink miss-hitting the printing paper P from being flown outside the upstream groove 126f, the downstream groove 126r, and the side grooves 126s (see FIG. 4). Such restriction protects the platen frame 125 of the color printer 20 from stains of ink droplets of each colored ink. The image data regarding the quality-enhancing ink CL is subjected to a preset series of processing. This prevents ink droplets of the quality-enhancing ink CL from being ejected in the peripheral area but to restrict ejection of ink droplets to the center area. The ink droplets of the quality-enhancing ink CL flown outside the printing paper P are dried up on the surface of the ink absorption materials 127r, 127f, and 127s and may interfere with smooth absorption of the color inks into the ink absorption materials 127r, 127f, and 127s. At step S300, the color conversion module 98 refers to the color conversion tables LUT and converts the RGB image data of the respective pixels into multi-tone data of the respective colored inks and the quality-enhancing ink available in the color printer 20. The color conversion tables LUT referred to here include a color conversion table LUTmid for the center area applied to the pixels belonging to the center area and a color conversion table LUTend for the peripheral area applied to the pixels belonging to the peripheral area. FIG. 8 shows the color conversion table LUTmid for the center area and the color conversion table LUTend for the peripheral area. Each of the color conversion tables LUTmid and LUTend stores settings of ink ejection volumes corresponding to R, G, and B tone values. The color conversion module 98 refers to these color conversion tables LUTmid and LUTend and determines the ejection volumes of the colored ink and the quality-enhancing ink corresponding to the tone values R, G, and B. The ink ejection volume may be expressed by a dot-recording rate, where 100% represents the state of filling all the pixels with ink droplets of any of these inks. Both the RGB image data and the ink ejection volumes are divided into 256 tones and may thus take tone values in the range of 0 to 255. FIGS. 9(a), 9(b) are graphs showing a variation in ejection volume of the quality-enhancing ink against the ejection volume of the colored ink in the center area. FIG. 9(a) shows a variation in ejection volume VCL of the quality-enhancing ink against the ejection volume VS of the colored ink in the center area. FIG. 9(b) shows a variation in total ejection volume VT (=VS+VCL) of the colored ink and the quality-enhancing ink against the ejection volume VS of the colored ink in the center area. The color conversion table LUTmid for the center area may have the settings of the ejection volume of the quality-enhancing ink shown in FIG. 9. These settings allow a greater volume of the quality-enhancing ink to be ejected in the area having a less ejection volume of the colored ink. This arrangement desirably prevents a variation of the gloss in printing on a relatively glossy printing medium, on the condition that the quality-enhancing ink has the similar gloss to that of the colored ink. This is because the area of the greater ink ejection volume tends to have the higher gloss in printing on the relatively glossy printing medium. In the color conversion table LUTend for the peripheral area, the ejection volume of the quality-enhancing ink is set equal to 0, irrespective of the ejection volume of the colored ink. Ejection of the quality-enhancing ink is prohibited in the peripheral area, in order to prevent ink droplets of the quality-enhancing ink from being flown outside the printing paper P. On some occasions, uniform ejection of the quality-enhancing ink may be desired, irrespective of the ejection volume of the colored ink. In such cases, the ejection volume of the quality-enhancing ink is also set equal to 0 in the color conversion table LUTend for the peripheral area. At step S400, the color-quantizing module 99 carries out color-quantizing to reduce 256 tones of the multi-tone data to, for example, 2 tones expressible in each pixel by the color printer 20. The 2 tones are expressed as ‘dot-on’ and ‘dot-off’ in this embodiment. At step S500, the print data generation module 100 rearranges the dot data representing the dot on-off state of the respective pixels in an order of transfer to the color printer 20 and outputs the rearranged dot data as final print data PD. The print data PD includes raster data representing dot-recording conditions in each main scan and data representing amounts of sub-scan feed. The procedure of this embodiment generates the dot data to prohibit ejection of the quality-enhancing ink CL with regard to the pixels belonging to the peripheral area. The dot data thus generated effectively prevents ink droplets of the quality-enhancing ink CL from being flown outside the printing paper P. This arrangement desirably prevents the ink droplets of the quality-enhancing ink CL from being dried up on the surface of the ink absorption materials 127r, 127f, and 127s and thereby assures smooth absorption of the colored inks into the ink absorption materials 127r, 127f, and 127s. As described previously, the center area is set such that restriction of ink ejection to the center area prevents any ink droplet from being flown outside the printing paper P, regardless of any potential error in sub-scan feed of the printing paper P or any potential flight error of ink droplets. Alternatively the center area may be set such that restriction of ink ejection to the center area prevents any ink droplet from being flown outside the printing paper P, in the absence of any potential error in sub-scan feed of the printing paper P or any potential flight error of ink droplets. The center area may otherwise be set to have a wider area. C. Print Data Generation Process of Second Embodiment FIGS. 10(a), 10(b) are plan views showing division of the area of the image data relative to the printing paper P in the second embodiment of the invention. In the structure of the second embodiment, the image data has a transition area between the center area and the peripheral area. The transition area is provided to prevent possible deterioration of the picture quality due to an abrupt change in ejection volume of the quality-enhancing ink between the peripheral area without ejection of the quality-enhancing ink and the center area with ejection of the quality-enhancing ink. The transition area is set to increase the ejection volume of the quality-enhancing ink from the neighborhood of the peripheral area to the neighborhood of the center area, as clearly shown in FIG. 10(b). In the illustrated example of FIG. 10, the transition area is divided into three zones, and three different color conversion tables with different settings of the ejection volume of the quality-enhancing ink are applied to the respective zones. The number of divisions of the transition area is, however, not restricted to three but may be set arbitrarily. In this example, a color conversion table having a relatively small tone value SM4 set to the maximum tone value of the quality-enhancing ink is applied to a zone of the transition area adjoining to the peripheral area. A color conversion table having a relatively large tone value SM2 set to the maximum tone value of the quality-enhancing ink is applied to a zone of the transition area adjoining to the center area. A color conversion table having the intermediate settings is adopted in the remaining middle zone of the transition area to assure a gentle variation in tone value of the quality-enhancing ink. This arrangement effectively prevents the appearance of a quasi-contour and deterioration of the picture quality due to an abrupt change in ejection volume of the quality-enhancing ink. The procedure of the second embodiment sets the transition area between the peripheral area and the center area to increase the ejection volume of the quality-enhancing ink from the neighborhood of the peripheral area to the neighborhood of the center area. This arrangement advantageously reduce potential deterioration of the picture quality due to an abrupt change in ejection volume of the quality-enhancing ink between the peripheral area and the center area. In the structure of the second embodiment, the transition area is set as part of the center area of the first embodiment. The transition area may, however, be set to cross the boundary between the center area and the peripheral area of the first embodiment. The transition area may otherwise be set as part of the peripheral area of the first embodiment. D. Print Data Generation Process of Third Embodiment FIGS. 11(a), 11(b) are plan views showing division of the area of the image data relative to the printing paper P in the third embodiment of the invention. The structure of the third embodiment has a transition area, like the structure of the second embodiment. The difference from the second embodiment is a method of determining the tone value of the quality-enhancing ink in the transition area. The procedure of the second embodiment applies the color conversion tables having the intermediate settings between the color conversion table for the peripheral area and the color conversion table for the center area to the transition area. The procedure of the third embodiment, on the other hand, determines the ejection volume of the quality-enhancing ink by linear interpolation of the color conversion table for the peripheral area and the color conversion table for the center area as shown by a solid-line plot in FIG. 11(b). The linear interpolation determines the ejection volume of the quality-enhancing ink according to the distance between each object pixel to be processed and the peripheral area or the center area. In this manner, the linear interpolation technique is applicable to determine the ejection volume of the quality-enhancing ink in the transition area, instead of application of the color conversion tables having the intermediate settings to the transition area. The procedure of the third embodiment adopts the linear interpolation technique in the transition area between the center area and the peripheral area. Non-linear interpolation may alternatively be performed for determination of the ejection volume of the quality-enhancing ink. One concrete procedure of non-linear interpolation sets a color conversion table at a preset point P in the transition area as shown by the dotted line in FIG. 11(b) and utilizes this color conversion table for stepwise linear interpolation. Another concrete procedure of non-linear interpolation uses a non-linear equation. The linear interpolation technique (including the stepwise linear interpolation technique), however, has the higher-speed advantage over the non-linear interpolation technique. The advantage of the non-linear interpolation technique is, on the other hand, a higher degree of freedom in interpolation. E. Print Data Generation Process of Fourth Embodiment FIGS. 12(a), 12(b) are plan views showing division of the area of the image data relative to the printing paper P in the fourth embodiment of the invention. The structure of the fourth embodiment has a transition area, like the structures of the second embodiment and the third embodiment. The difference from the second and the third embodiments is a method of determining the tone value of the quality-enhancing ink in the transition area. The procedure of the fourth embodiment divides the transition area into two zones, that is, a first transition area and a second transition area, and applies different techniques of determining the ejection volume of the quality-enhancing ink to these two transition areas. The first transition area is an upper zone of the transition area in FIG. 12(a), and the second transition area is a remaining zone of the transition area. The technique adopted in the first transition area is application of a color conversion table for the transition area like the second embodiment to determine the ejection volume of the quality-enhancing ink (see FIG. 12(b)). The technique adopted in the second transition area is interpolation like the third embodiment to determine the ejection volume of the quality-enhancing ink (not shown). Application of the different techniques to the respective divisions of the transition area to determine the ejection volume of the quality-enhancing ink effectively shortens the total time required for the color conversion. The procedure of the fourth embodiment carries out color conversion with regard to each of the main scanning lines from the upper side in FIG. 12(a). Namely the procedure first makes a top-most main scanning line, which is a set of pixels aligned on an upper-most end in the main scanning direction, subjected to color conversion and then processes a next main scanning line immediately below the top-most main scanning line on completion of the processing of the top-most main scanning line. Each main scanning line is a set of consecutive pixels aligned in the main scanning direction. One identical color conversion table is applicable to process the respective main scanning lines in the first transition area. The first transition area is accordingly processable at a higher speed by application of the color conversion table for the transition area like the second embodiment to determine the ejection volume of the quality-enhancing ink than the interpolation in the respective pixels like the third embodiment. Processing of the respective main scanning lines in the second transition area, however, requires multiple color conversion tables. The method of the second embodiment reads the multiple color conversion tables from a non-illustrated memory into a non-illustrated cache memory multiple times. Such reading takes time. The second transition area is thus processable at a higher speed by the interpolation technique like the third embodiment to determine the ejection volume of the quality-enhancing ink. In the course of color conversion with regard to each of the main scanning lines, which is a set of consecutive pixels aligned in the main scanning direction, the interpolation technique is applied to determine the ejection volume of the quality-enhancing ink in the specific zone of the transition area where one main scanning line is unprocessable with one identical color conversion table. This procedure advantageously enhances the total processing speed. The technique of the fourth embodiment is applicable to a modified structure where the sub-scanning direction replaces the main scanning direction. F. Modifications The embodiments discussed above are to be considered in all aspects as illustrative and not restrictive. There may be many modifications, changes, and alterations without departing from the scope or spirit of the main characteristics of the present invention. Some examples of possible modification are given below. F-1. Each of the embodiments discussed above adopts the systematic dither method for reduction of the number of tone values. Another color-quantizing technique like the error diffusion method or the density pattern method is applicable to reduce the number of tone values. One-to-one mapping of pixels in image data to pixels on a printing medium is not necessary. One pixel in the image data may be mapped to multiple pixels on the printing medium. F-2. The embodiments discussed above regard the inkjet printers with piezoelectric elements. Each of the techniques of the respective embodiments is also applicable to bubble jet printers that eject ink droplets by means of bubbles produced in the ink through power supply to heaters attached to nozzles, diversity of other printers, and variety of other printing devices. F-3. In the embodiments discussed above, the tone value of the quality-enhancing ink in the peripheral area is set equal to zero in the color conversion process that makes the color in each pixel of given image data expressed by the tone values of the colored inks and the quality-enhancing ink available in the color printer 20. One modified procedure may set the dot-recording rate of the quality-enhancing ink in the peripheral area equal to zero in the color-quantizing process for reducing the number of tone values. F-4. In the respective embodiments discussed above, the printing medium is the rectangular cut paper P. The technique of the invention is also applicable to printing on roll paper extending in the sub-scanning direction. In the case of printing on roll paper R, it is preferable to set the peripheral area and the transition area in the image data corresponding to only side ends of the printing medium parallel to the sub-scanning direction, as shown in FIG. 13. This arrangement desirably relieves the load of data processing of the image data corresponding to the remaining ends of the printing medium parallel to the main scanning direction, in the case of printing multiple images on the roll paper. This arrangement also advantageously prevents potential deterioration of the picture quality of a printed material, due to an abrupt decrease in ejection volume of the quality-enhancing ink. F-5. In the embodiments discussed above, the print data is generated such that ejection of the quality-enhancing ink is prohibited in the peripheral area, in order to prevent the quality-enhancing ink from being flown outside the printing medium. One modified structure may set an operation mode, in which the control circuit 40 of the printer 20 restricts (stops or reduces) ejection of ink from nozzles for the quality-enhancing ink, in the case where the nozzles for the quality-enhancing ink are located in the peripheral area. One applicable method to the restriction (stop or reduction) rewrites the contents of the raster data. Another applicable method opens a circuit to driving elements of the ink. F-6. The technique of the invention is not restricted to color printing but is also applicable to monochromatic printing. The technique is also applicable to a printing system that is capable of creating multiple dots in one pixel to express multiple tones. F-7. In the embodiments discussed above, the dot-recording rate of the quality-enhancing ink is set equal to zero with regard to the pixels belonging to the peripheral area. Setting the dot-recording rate to zero is, however, not essential. The only requirement is that the dot-recording rate of the quality-enhancing ink in the pixels of the peripheral area is set lower than the dot-recording rate of the quality-enhancing ink in the pixels of the center area. For example, the dot-recording rate of the quality-enhancing ink in the center area may be set equal to approximately 10%, while the dot-recording rate of the quality-enhancing ink in the peripheral area may be set to be not greater than 1%. F-8. In the embodiments discussed above, the dot-recording rate of the quality-enhancing ink is uniformly set equal to zero with regard to the pixels belonging to the peripheral area. If the quality-enhancing ink is absorbable by the ink absorption material like the colored links, however, complete reduction of the dot-recording rate of the quality-enhancing ink is not required with regard to the pixels included in the peripheral area. The dot data generation module of the invention is generally designed to have a processing mode that makes the ink dot-recording rate of the quality-enhancing ink in the pixels of the peripheral area lower than the ink dot-recording rate of the quality-enhancing ink in the pixels of the center area. F-9. In the respective embodiments discussed above, part of the hardware configuration may be replaced by the software, while part of the software configuration may be replaced by the hardware. For example, part or all of the functions of the printer driver 96 shown in FIG. 1 may be executed by the control circuit 40 included in the printer 20. In this modified structure, part or all of the functions of the computer 90 as the printing control apparatus of generating print data is attained by the control circuit 40 of the printer 20. Part or all of the functions of the invention may be actualized by the software. In such cases, the software (computer programs) may be supplied in the form recorded in a computer readable recording medium. In the terminology of this invention, the ‘computer readable recording medium’ is not restricted to portable recording media like flexible disks and CD-ROMs but includes internal storage devices of the computer like various RAMs and ROMs and external storage devices fixed to the computer like hard disks. All changes within the meaning and range of equivalency of the claims are intended to be embraced therein. The scope and spirit of the present invention are indicated by the appended claims, rather than by the foregoing description. Finally, the present application claims the priority based on Japanese Patent Application No. 2003-193262 filed on Jul. 8, 2003, which is herein incorporated by reference. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a printing technique that ejects ink droplets of multiple types of inks on a printing medium to print an image. 2. Description of the Related Art Printers that eject inks from nozzles on a print head have widely been used as an output unit of the computer. There is a known printer that is capable of printing an image to respective ends of printing paper (see Japanese Patent Laid-Open Gazette No. 2002-103586). One proposed method to attain such margin-free printing uses ink absorption materials set in grooves of a platen to absorb ink ejected outside the printing paper. Quality-enhancing ink is used to enhance the quality of printed materials, for example, enhancement of color development, water resistance, and light resistance and reduction of a variation in gloss. The Quality-enhancing ink may, however, be dried up on the surface of the ink absorption materials and interfere with smooth absorption of colored inks into the ink absorption materials. The Quality-enhancing ink is used not for coloring but for improvement of the quality of the printed materials. Partial absence of the Quality-enhancing ink thus does not significantly deteriorate the quality, additionally the deterioration of the quality is rather inconspicuous at the ends of the printed materials. | <SOH> SUMMARY OF THE INVENTION <EOH>The object of the invention is to provide a printing technique that prints an image to respective ends of a printing medium, while reducing ejection of ink droplets of quality-enhancing ink outside the printing medium. In order to attain the above objects of the present invention, there is provided a printing control method of generating print data to be supplied to a print unit to print. The print unit forms dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material. The printing control method comprises the dot data-generating step of generating dot data representing a state of dot formation at each pixel in a printed image to reproduce an image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit. The step includes a processing mode configured to make a quality-enhancing ink dot-recording rate for pixels belonging to a peripheral area lower than the quality-enhancing ink dot-recording rate for pixels belonging to a center area with regard to at least one identical pixel value of the image data. The quality-enhancing ink dot-recording rate is a dot-recording rate of the quality-enhancing ink. The peripheral area is set at end portions of the printing medium. The center area is set in a central portion of the printing medium. The printing method of the invention is capable of making the quality-enhancing ink dot-recording rate for the pixels belonging to the peripheral area lower than the quality-enhancing ink dot recording rate for the pixels belonging to the center area. This arrangement ensures printing to the respective ends of the printing medium, while reducing ejection of ink droplets of the quality-enhancing ink outside the printing medium. In the specification hereof, the terminology “printed material” represents a print obtained by ejection of ink droplets of the colored ink and the quality-enhancing ink on the printing medium. The terminology “quality-enhancing ink” represents ink used for enhancing the quality of printed materials, for example, enhancement of color development, water resistance, and light resistance and reduction of a variation in gloss. The present invention can be realized in various forms such as a method and apparatus for printing, a method and apparatus for printing control, and a computer-program product implementing the above scheme. These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings. | 20040707 | 20091103 | 20050217 | 58002.0 | 0 | VO, QUANG N | EJECTION CONTROL OF QUALITY-ENHANCING INK | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,887,121 | ACCEPTED | Fractal harmonic overtone mapping of speech and musical sounds | An apparatus for signal processing based on an algorithm for representing harmonics in a fractal lattice. The apparatus includes a plurality of tuned segments, each tuned segment including a transceiver having an intrinsic resonant frequency the amplitude of the resonant frequency capable of being modified by either receiving an external input signal, or by internally generating a response to an applied feedback signal. A plurality of signal processing elements are arranged in an array pattern, the signal processing elements including at least one function selected from the group including buffers for storing information, a feedback device for generating a feedback signal, a controller for controlling an output signal, a connection circuit for connecting the plurality of tuned segments to signal processing elements, and a feedback connection circuit for conveying signals from the plurality of signal processing elements in the array to the tuned segments. | 1. An apparatus for signal processing based on an algorithm for representing harmonics in a fractal lattice, the apparatus comprising: (a) a plurality of tuned segments, each tuned segment including a transceiver having an intrinsic resonant frequency the amplitude of the resonant frequency capable of being modified by at least one of the group consisting of receiving an external input signal, and internally generating a response to an applied feedback signal; (b) a plurality of signal processing elements arranged in an array pattern, the signal processing elements including at least one function selected from the group consisting of buffer means for storing information, feedback means for generating a feedback signal, controller means for controlling an output signal, connection means for connecting the plurality of tuned segments to signal processing elements, and feedback connection means for conveying signals from the plurality of signal processing elements in the array to the tuned segments. 2. The apparatus according to claim 1 wherein the tuned segments are arranged consecutively in a cochlea-like pattern and together form an active cochlear model device. 3. The apparatus according to claim 1, wherein individual ones of the signal processing elements include a neural-column structure having a plurality of layers, at least some of which layers are capable of functioning as counting circuits. 4. The apparatus according to claim 3, wherein the counting circuits are selected from the group consisting of 2:1 counters, 3:1 counters, 5:1 counters, 7:1 counters, and 11:1 counters. 5. The apparatus according to claim 3, wherein the plurality of signal processing elements are arranged so that an output from the counting circuits can be directed to a counting circuit in another signal processing element in order to generate a plurality of signals at subharmonic frequencies, each subharmonic frequency being associated with a separate signal processing element. 6. The apparatus according to claim 1, wherein the algorithm comprises the steps of: (a) creating a rectangular array, with position along the row indicating magnitude in the first dimension and position in the column indicating magnitude along a second dimension; (b) making a plurality of copies of the array and displacing them horizontally for the next dimension, the plurality of arrays indicating the various magnitudes; (c) making a plurality of copies of all the previous arrays and displacing them vertically, the plurality of arrays corresponding to various magnitudes in the next dimension, and the totality in effect being a larger array; (d) repeating step (b) and then step (c) alternately for subsequent dimensions; and (e) associating a value R with each point on a fractal lattice according to a formula having a factor for each dimension, with each factor having an integer exponent for each magnitude, the formulae following the prototype: associating a value R with each point (j,k,l,m,n) on the fractal lattice, according to the formula for five dimensions: #EQ1# R=2.sup.j*3.sup.k*5.sup.L*7.sup.m*11.sup.n. where the factors 2, 3, 5, 7, and 11 are dimensions and j, k, l, m, and n are magnitudes. 7. The apparatus according to claim 1, wherein a fractal lattice of a reduced number of dimensions is provided, with mapping based on: (a) four dimensions corresponding to the factors 3, 5, 7, and 11; (b) mapping based on three dimensions corresponding to the factors 3, 5, and 7 or the factors 3, 5, and 11; (c) mapping based on the two dimensions corresponding to the factors 3 and 5; and (d) in (a), (b), and (c), associating values to points on the fractal lattice according to a formula with a factor for each dimension, and integer exponents for each magnitude. 8. The apparatus according to claim 1, wherein a fractal lattice with dimensions numbering greater than five is constructed based on factors selected from the group consisting of 13, 17, 19, 23, and higher prime numbers; and a fractal lattice is constructed based on factors that are composite numbers, the mapping associating values with points on the fractal lattice according to a formula with a factor for each dimension, and integer exponents for each magnitude. 9. The apparatus according to claim 1, and including feedback adjustment means for adjusting feedback to tuned segments to provide a subthreshold signal (at the characteristic frequency) that improves sensitivity to amplitudes near a threshold value. 10. The apparatus according to claim 9, wherein feedback signals are fed from a plurality of points forming a pattern on a fractal map that includes harmonically related signals that minimize interference beating due to alternating constructive and destructive interference. 11. The apparatus according to claim 9, wherein feedback signals are from a plurality of points forming a pattern on a fractal map that are sampled rapidly to maintain phase sensitivity and produce a strobing effect in the cochlear model. 12. The apparatus according to claim 9, wherein harmonically related signals of similar phase derived from subharmonic generators are used to reinforce input signals at tuned segments by subthreshold strobing at the characteristic frequency of such segments. 13. The apparatus according to claim 9, wherein feedback signals are fed from a plurality of points on a fractal map having subregions with at least two separate phases simultaneously, each phase directed to distinct segments of the cochlear model, including but not limited to those responding to input signals from different sources. 14. The apparatus according to claim 9, wherein feedback signals from a single point on a fractal map are directed to a plurality of segments that correspond to magnitudes along one of the dimensions of the fractal map, wherein the magnitudes are selected from a multiplexed signal from one signal processing element to multiple segments having characteristic frequencies F, 2F, 4F, 8F, 16F and 32F. 15. The apparatus according to claim 9, wherein feedback signals from a plurality of points forming a pattern that moves sequentially across a fractal map are directed to a plurality of tuned segments to reinforce transient input signals. 16. The apparatus according to claim 1, wherein signal processing elements are combined to function as a rhythm generator for output signals or information storage. 17. The apparatus according to claim 1, wherein an optimal number of tuned segments and signal processing elements are determined by the degree of fine-grainedness and speed of acquisition of the input signal. 18. The apparatus according to claim 1, wherein an optimal number of tuned segments and signal processing elements are determined by the degree of fine-grainedness and speed of a feedback response. 19. The apparatus according to claim 1, wherein an optimal number of dimensions in the fractal lattice and range of values in each dimension is sensitivity and specificity of input and feedback signals of the individual tuned segments of the transceiver. 20. The apparatus according to claim 1, wherein an optimal number of dimensions in the fractal lattice and range of values in each dimension is determined by computational complexity and processing speed. 21. The apparatus according to claim 1, wherein the fractal lattice includes guide means for guiding an organizational pattern for local sections of the array by performing at least one of the processes in a group consisting of: (a) establishing sensory and feedback connections between the signal processing element for a given frequency and the tuned segment having approximately the same characteristic frequency; (b) generating a plurality of subharmonic signals that fall within the relevant frequency range of the tuned segments, and tentatively connecting these signal processing elements to the appropriate tuned segments; (c) selecting unassigned tuned segments and tentatively connecting them to available signal processing elements at dispersed points in the array, approximately matching the intrinsic frequency of each tuned segment with signal processing elements that can create a rhythm generator for another local area of subharmonic frequencies; (d) maintaining areas of overlapping subharmonics if their interacting counting circuits can be shared and are consistent, and removing the tentative connections if they are inconsistent; (e) removing the tentative connections from elements in the array if their feedback goes to neighboring tuning segments that are too close together, so that similarly tuned neighboring segments become associated with signal processing elements that are widely spaced; and (f) continuing until signal processing elements are connected to a sufficient number of tuning segments and a sufficient number of subharmonic generators have been organized to cover the array. 22. The apparatus according to claim 1, wherein the apparatus comprises a computer readable medium. 23. A method of signal processing based on an algorithm for distributed representation of signals, and of the harmonic relations between components of such signals, represented by a fractal lattice which includes multiple dimensions based on harmonic fields, the method comprising the steps of: (a) mapping input signals to signal processing elements arranged in an array; (b) processing signals to generate a plurality of feedback signals at subharmonic frequencies; and (c) combining the plurality of feedback signals with subsequent input signals. 24. The method according to claim 23, and further including the step of providing additional harmonic information in an expanded fractal lattice reflecting a dimension selected from the group consisting of 13, 17, 19, 23, and higher prime numbers. 25. The method according to claim 23, and including the step of simplifying the algorithm by removing one or more factors in order to allow a fractal lattice of a recorded dimension. 26. The method according to claim 23, and including the step of modeling an input signal as a spectral representation selected from the group consisting of a discrete Fourier transform and a logarithmic frequency spectrum. 27. The method according to claim 23, and including the step of deriving the input signal from speech sounds. 28. The method according to claim 23, and including the step of deriving the input signal from the group consisting of musical sounds, a mixture of speech and music, and a mixture of audio signals other than speech, music and a mixture of speech and music. 29. The method according to claim 23, and including the step of deriving the input signal from signals of unknown origin. 30. A computer readable medium having instructions for performing steps according to the method of claim 23. 31. A method for connecting tuned segments to elements in a signal processing array, the method including a step selected from the group consisting of: (a) establishing initial sensory and feedback connections between a signal processing element for a given frequency and a tuned segment having approximately the same characteristic frequency; (b) making connections to segments with a frequency lower than a given segment, by generating a plurality of subharmonic signal that fall within the relevant frequency range of the tuned segments, and tentatively connecting at least one signal processing elements to the appropriate tuned segments; (c) making connections to segments with a frequency higher than a given segment, by using a fractal map with a reduced number of dimensions so that the magnitude along one dimension is not specified; (d) allowing in effect a multiplexed feedback signal from a point in the fractal map, such as a signal at characteristic frequencies F, 2F, 4F, 8F, 16F and 32F; (e) selecting unassigned tuned segments and tentatively connecting them to available signal processing elements at dispersed points in the array, thereby approximately matching the intrinsic frequency of each tuned segment; (f) balancing the processes of connecting signal processing elements to lower frequency segments and the process of connecting signal processing elements to higher frequency segments; (g) maintaining areas of overlapping subharmonics if their interacting counting circuits can be shared and are consistent, and removing tentative connections if they are inconsistent; (h) maintaining connections to points in the fractal map of higher frequency if their multiplexed signals are consistent, and removing tentative connections from the points in the fractal map if they are inconsistent; and (i) repeating any one of steps (a)-(h) until signal processing elements are connected to a sufficient number of tuning segments, and a sufficient number of subharmonic generators have been organized to cover the array. | This application is based on and claims priority from provisional application Ser. No. 60485,546, filed Jul. 8, 2003. TECHNICAL FIELD AND BACKGROUND OF THE INVENTION This invention relates to fractal harmonic overtone mapping of speech and musical sounds for high-resolution, dynamic control of input sensitivity, adaptive control of output acoustics and phonology, and for information storage and pattern recognition. Current strategies for computer speech recognition and voice analysis are generally based on processes that transform information derived from the frequency spectrum of sound. The primary tools in spectral analysis of sound are the Fourier transform and many variants. A large variety of mathematical functions such as inverse spectral (“cepstral”) and wavelet analyses have also been applied to speech perception. Current strategies for speech processing reflect the theory that sound is perceived in the inner ear tonotopically, with location along the cochlea correlating with frequency. A number of prior patents explain the current strategies for signal processing and their limitations. For example, U.S. Pat. No. 6,124,544 teaches that autocorrelation has proven unreliable. One reason that is mentioned is that the sample rate can introduce artifacts. U.S. Pat. No. 6,701,291 supports advantageously adjusting, in a coordinated manner, a handful of parameters. U.S. Pat. No. 6,584,437 reviews coding methods that use a lattice to encode pitch periods and differences between pitch periods. U.S. Pat. No. 6,658,383 explains how speech and musical signals are approached differently in the current art. A proposed solution is to encode signals with several modes, using different modes for musical signals and voiced speech signals. U.S. Pat. No. 6,658,383 does not, however, address unvoiced speech. U.S. Pat. No. 6,725,190 discloses various approaches to coding speech including a proposal for phase-binned speech but requires separate accounting based on a “voicing decision.” U.S. Pat. No. 6,745,155 discusses input from a “basilar membrane model device”, with time delays or autocorrelation as a means for signal analysis. U.S. Pat. No. 6,732,073 discloses a way of enhancing a frequency spectrum, using the history of sound signals a short interval before as well as information about sound signals a short interval afterward. The inclusion of information over time is a key aspect of many current approaches to signal analysis. Cochlea, the Latin word for “chamber,” is pronounced either as “coke”-lee-uh or as in the phrase “the cockles of the heart” (from the Latin cochleae cordis, “chambers of the heart”). Like the heart, it has a spiral shape (a “cockleshell”), which acts somewhat like a prism to separate sound into its various component frequencies. Frequency information is processed in the inner ear, which consists of the cochlea, the cochlear nucleus, and a variety of brain centers. There are three problems with a psychoacoustic model that uses only tonotopic frequency information. Critical bands, which limit our ability to hear frequencies that are too close together, indicate that there is a signal processing mechanism along the length of the cochlea that may provide contrast enhancement or automatic gain control. Experiments show that for typical tones, the fundamental and harmonic overtones 2 through 6 are perceived as distinct tones and higher harmonics are perceived as a fused “residue tone” or “residual tone.” Humans apparently can only be consciously aware of harmonic overtones that are far enough apart to fall into separate critical bands. Humans cannot hear harmonic overtones that are “too close together.” However, this does not preclude possible mechanisms that advantageously make use of information in higher harmonic overtones via unconscious processes. Signal processing via such “hidden Markov models” is a common theme in neural network modeling. “Active hearing” refers to recent advances in our understanding of the mechanism of hearing including the function of the protein prestin and the presence of a spectrum of self-reinforcing vibrations in the inner ear. These reverberations are due to positive feedback loops across the width of the cochlea involving outer hair cells and their stereocilia. Stereocilia act as valves that control the flow of charged ions (like transistors, controlling the flow of more power than they absorb, according to C. D. Geisler, From Sound to Synapse, Oxford Univ Press, 1998). When movement of an outer hair cell's stereocilia change its voltage, the protein prestin causes the cell to elongate or contract. (D. Oliver et al., Science 292, 2340, 2001). This rocks the cochlear partition, which triggers the cell's stereocilia, causing the cycle to repeat. In effect, each segment of the cochlea is a regenerative receiver. This is the historical term used for radio receivers that used positive feedback. They invariably had a regeneration control to vary the amount of positive feedback (Philip Hoff, Consumer Electronics for Engineers, Cambridge Univ Press, 1998). According to active hearing, when a sound is initially perceived there may be a gesture-like shift in the reverberations in the cochlea. Hearing a sound may force the cochlea to “tune in.” This type of process would be analogous to “adaptive optics” and would require dynamic feedback with a time scale estimated to be on the order of 0.5 ms. Thus, the function of the cochlea is more than a prism-like separation of sound into its component frequencies. Multiple maps of auditory space have been suggested by experiments involving researchers wearing distorting earpieces that disrupt their ability to judge whether sounds are “up” or “down.” (P. M. Hofman, J. G. A. Van Riswick, A. J. Van Opstal, Nature Neuroscience, 1 (5)417,1998). Unlike experiments with distorting eyeglasses, which take time for readjustment afterwards, correct sound localization occurred immediately when the fake ears were removed. Thus, shifting between cortical representations is possible, raising the question of how frequency information distributed along the cochlea (a one-dimensional analog) could be sufficient to model the three-dimensional world. An additional problem is how the complexity of multiple maps would be managed. Two innovationssolutions were developed by the author. The first is from the field of neural network signal processing and is the concept “harmonic fields.” The second is from the field of optimization theory and is an extension of the mathematical concept of an adaptive walk on a virtual landscape, “fractal mapping.” If the virtual landscape is a map of the neuromuscular patterns for sound in the throat and also the sensorineural patterns for sound in the ear, combined with the neural feedback for dynamic control of active hearing in the cochlea, optimization of the multiple interacting streams of data applying to different size scales but have similar recursive possibilities could occur. The result would be similarity and function across different size scales, leading the author to the concept “a fractal map of harmonic overtone space.” The invention was developed in the course of research for the paper, “Fractal harmonic reconstruction of ancient South Asian musical scales,” by Robert Patel Quinn, M. D. The invention is introduced as a method for analyzing harmonic overtones, which are high pitch sounds that have frequencies which are an exact multiple of the fundamental frequency. Although a frequency can be described both as a harmonic and as an overtone, the terminology employed in the paper distinguishes harmonics from overtones by using numbers for harmonics and letters for overtones, and uses the convention that harmonic 1 is the fundamental frequency of a tone. Musical notes are drawn as a column (a musical staff) with higher pitch harmonic overtones at the top and the fundamental at the bottom. In contrast to neural network signal processing models of the sense of touch and vision, which involve “receptive fields” that are spatially contiguous, the olfactory system processes smells by “molecular receptive range.” (K. Mori, Y. Yoshihara, Progress in Neurobiology, Vol 45, 585, 1995). An analogous process in the ear could correlate sounds an octave apart, leading to harmonic fields. Harmonic fields can be visualized (FIG. 3) as a connection (a neuron) linking two points in the cochlea; for example, those that correspond to harmonics 9 and 3. Another example of a harmonic field is shown by the neuron linking harmonics 3 and 1. Each neuron would also function as a “sensor” for coinciding harmonics 6 and 2 of other tones with different fundamentals, reinforcing the linking relationship; the harmonic fields are detectors of the ratio rather than of specific numbers. Higher order connections between these neurons (“neural networking”) and signals flowing toward the brain as well as “active hearing” signals flowing toward the cochlea are important components of the fractal harmonic overtone mapping model. The hypothesized harmonic fields are scanned and the results are integrated into a multi-dimensional map. The illustration shows that sound first enters the inner ear at the high-frequency end of the cochlea. Depending on the speed of sound in the fluid of the cochlea and the speed and course of neural signals, this may be a reason that harmonics are scanned from high to low frequencies, although the spiral design of the cochlea tends to ensure that harmonics are perceived roughly simultaneously. A more fundamental reason why high frequency harmonics would be expected to be perceived first is the fact that the higher sampling rates possible at high frequencies would allow the wavelength of sound to be identified faster. “Inharmonic fields” would not be expected to develop. Unevenly spaced “inharmonic fields” would not be expected to develop naturally in the nervous system since reinforcement would not occur from inputs with a variety of fundamental frequencies if their harmonics were not appropriately spaced. If designed according to a genetic algorithm approach, efficiency suggests that some harmonic fields are redundant. An evolutionary approach would tend to produce enough complexity to exploit information but not too much for processing. The paper proposes the assumption that “harmonic fields develop only for tones that provide new information (the prime factors 2, 3, 5, 7, and 11).” This is because scanning through these prime number ratio harmonic fields (looking for simultaneous or near-simultaneous sounds) and then using other neurons to scan for simultaneous or near-simultaneous “higher order” correlations of neural network signals would result in information that can be recorded in a consistent fashion on a five dimensional fractal map. Information associated with ratios such as 4, 6, 8, 9, 10 or 12 would be included in the map, offset by an appropriate magnitude. It would be redundant to require separate dimensions to represent the same information. Prime-numbered fields would carry new information. The information from harmonic fields would constitute parallel channels (streams) of information. Parallel processing would allow hidden Markov models to solve the problems of phonology and segmenting the stream of speech. This is currently the major roadblock to current strategies for computer speech recognition and voice analysis which do not perform signal processing in terms of categorical features. The method section of the author's paper, “Fractal harmonic reconstruction of ancient South Asian musical scales,” opens with, “The basic idea of a fractal is that the same processes, or the same statistics or properties of a figure, are found at all size levels. In a fractal representation of multidimensional space each feature of the fractal represents a different axis and the range of values (magnitude) of each feature is plotted along that axis. Familiarity with the relationship between points on one or two axes gives familiarity with the relationships between points on all axes” (See to “B. Levitan; santafe.edu\nk.html.”) “We can map out a rectangular array using the first two factors, then for the next factor we add another array displaced horizontally, followed by a copy of the arrays displaced vertically. By alternating these steps as we add successive factors, we develop the recursive property that gives the representation its fractal nature.” These steps establish that a multidimensional map can be graphically represented in two dimensions. It should be noted that the cited online article by Bennett Levitan was an explanation of how he and Simon Pariser could graphically display various nucleic acid base pairs and the way they mutated to become codons for other amino acids. Although this is in a different field, the pattern of iterative steps (first left to right, then top to bottom, then left to right, etc.) was followed in constructing the fractal harmonic overtone map in order to establish a consistent convention. SUMMARY OF THE INVENTION Therefore, it is an object of the invention to provide a fractal representation of harmonic fields and fractal harmonic overtone mapping for high-resolution, dynamic control of input sensitivity. It is another object of the invention to provide a fractal representation of harmonic fields and fractal harmonic overtone mapping for adaptive control of output acoustics and phonology. It is another object of the invention to provide a fractal representation of harmonic fields and fractal harmonic overtone mapping for information storage and pattern recognition for speech and music. These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing an apparatus for signal processing based on an algorithm for representing harmonics in a fractal lattice, the apparatus comprising a plurality of tuned segments, each tuned segment including a transceiver having an intrinsic resonant frequency the amplitude of the resonant frequency capable of being modified by either receiving an external input signal, or by internally generating a response to an applied feedback signal. A plurality of signal processing elements arranged in an array pattern. The signal processing elements include at least one function selected from the group consisting of buffer means for storing information, feedback means for generating a feedback signal, controller means for controlling an output signal, connection means for connecting the plurality of tuned segments to signal processing elements, and feedback connection means for conveying signals from the plurality of signal processing elements in the array to the tuned segments. According to one preferred embodiment of the invention, the tuned segments form a combined sensor unit arranged in a cochlea-like pattern. According to another preferred embodiment of the invention, individual ones of the signal processing elements include a neural-column structure having a plurality of layers, at least some of which layers are capable of functioning as counting circuits, selected from the group of counting circuits selected from the group of 2:1 counters, 3:1 counters, 5:1 counters, 7:1 counters, and 11:1 counters. According to yet another preferred embodiment of the invention, the plurality of signal processing elements are arranged so that an output from the counting circuits can be directed to counting circuits in other signal processing elements in order to generate a plurality of signals at subharmonic frequencies, each subharmonic frequency being associated with a separate signal processing element. According to yet another preferred embodiment of the invention, the fractal lattice includes guide means for guiding an organizational pattern for local sections of the array by performing at least one of the processes in a group of process steps consisting of establishing sensory and feedback connections between the signal processing element for a given frequency and the tuned segment having approximately the same characteristic frequency, generating a plurality of subharmonic signals that fall within the relevant frequency range of the tuned segments, and tentatively connecting these signal processing elements to the appropriate tuned segments, selecting unassigned tuned segments and tentatively connecting them to available signal processing elements at dispersed points in the array, approximately matching the intrinsic frequency of each tuned segment with signal processing elements that can create a rhythm generator for another local area of subharmonic frequencies, maintaining areas of overlapping subharmonics if their interacting counting circuits can be shared and are consistent, and removing the tentative connections if they are inconsistent, removing the tentative connections from elements in the array if their feedback goes to neighboring tuning segments that are too close together, so that similarly tuned neighboring segments become associated with signal processing elements that are widely spaced, and continuing until signal processing elements are connected to a sufficient number of tuning segments and a sufficient number of subharmonic generators have been organized to cover the array. According to yet another preferred embodiment of the invention, the optimal number of the tuned segments and the signal processing elements are determined by the degree of fine-grainedness and speed of acquisition of the input signal. According to yet another preferred embodiment of the invention, the optimal number of tuned segments and signal processing elements are determined by the degree of fine-grainedness and speed of the feedback response. According to yet another preferred embodiment of the invention, the number of dimensions in the fractal lattice and range of values in each dimension are determined by transceiver characteristics selected from the group consisting of sensitivity of input, specificity of input and feedback signals of the individual tuned segments. According to yet another preferred embodiment of the invention, the number of dimensions in the fractal lattice and range of values in each dimension are of a predetermined computational complexity. According to yet another preferred embodiment of the invention, the number of dimensions in the fractal lattice and range of values in each dimension are determined by processing speed. According to yet another preferred embodiment of the invention, the apparatus including means for selectively transmitting a plurality of feedback signals to adjacent tuned segments which would otherwise be subject to alternating constructive and destructive interference, wherein the feedback signals are selected from neighboring signal processing elements for minimizing interference beating. According to yet another preferred embodiment of the invention, the invention includes harmonic derivation means for deriving harmonically related signals of similar phase from subharmonic generators and using the related signals to add energy to various tuned segments by subthreshold strobing at the characteristic frequency of such segments. According to yet another preferred embodiment of the invention, the invention includes signal selection means for selecting signals of non-adjacent segments from signal processors elements to allow signals with different phases to be reinforced by differently-phased strobing feedback signals. According to yet another preferred embodiment of the invention, a method of signal processing based on an algorithm for distributed representation of signals, and of the harmonic relations between components of such signals, represented by a fractal lattice which includes multiple dimensions based on harmonic fields is provided, the method comprising the steps of mapping input signals to signal processing elements arranged in an array, processing signals to generate a plurality of feedback signals at subharmonic frequencies, combining the plurality of feedback signals with subsequent input signals. According to yet another preferred embodiment of the invention, the algorithm comprises EQ#R=2.sup.j*3.sup.k*5.sup.L*7.sup.m*11.sup.n. According to yet another preferred embodiment of the invention, the method includes the further step of providing additional harmonic information in an expanded fractal lattice reflecting a dimension selected from the group consisting of 13, 17, 19, and 23. According to yet another preferred embodiment of the invention, the method includes the step of simplifying the algorithm by removing one or more factors in order to allow a fractal lattice of a recorded dimension. According to yet another preferred embodiment of the invention, the method includes the step of modelling an input signal as a spectral representation selected from the group consisting of a discrete Fourier transform and a logarithmic frequency spectrum. According to yet another preferred embodiment of the invention, the method includes the step of deriving the input signal from speech sounds. According to yet another preferred embodiment of the invention, the method includes the step of deriving the input signal from the group consisting of musical sounds, a mixture of speech and music, and a mixture of audio signals other than speech, music or a mixture of speech and music. According to yet another preferred embodiment of the invention, the method includes the step of deriving the input signal from signals of unknown origin. According to yet another preferred embodiment of the invention, a computer readable medium is provided having instructions for performing steps according to the method. BRIEF DESCRIPTION OF THE DRAWINGS Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the invention proceeds when taken in conjunction with the following drawings, in which: FIG. 1 shows the general outline of the four essential elements of fractal harmonic overtone mapping and the feedback loops from which its properties emerge; FIG. 2 shows the tonotopic orientation of the cochlea, and the harmonic overtones for the notes of the 12-division octave eliminating names with sharps and flats, using the notation for the white keys CDEFGAB and the black keys PQ XYZ of the piano keyboard (using the mnemonic “PDQ”) with the equivalences P=C#/Db, Q=D#/Eb, X=F#/Gb, Y=G#/Ab, Z=A#/Bb; FIG. 3 shows harmonic fields in the cochlea, and demonstrates the harmonic fields that correspond to factors 2, 3, 5, 7, and 11; FIG.4 shows how multidimensional maps are constructed, similar to the process for playing three-dimensional Tic-tac-toe with iterative steps to give the map a fractal nature; FIG. 5 shows a 3-dimensional fractal map, simplified to illustrate a musical scale with two dimensions (a “diatonic scale”); FIGS. 6 and 7 show the general pattern of fractal mapping of harmonic overtone space. Maps are centered around C1. In FIG. 6, the basic “A to Z” pattern of 12 rows and 3 columns (12 rows for the dimension 3K, and 3 columns for the dimension 5L) gives a 12×3 array that tessellates over the fractal map. The letter pattern can be extended indefinitely over the map of harmonic overtones in the array defined by the 3K and 5L dimensions based on the factors 3 and 5. The first drawing is the two-dimensional “k by l” array “from A to Z” that shows how each point in an array can be associated with an exact ratio musical note (indicated with an approximate letter tone, each of which is unique). C in the second row, third column corresponds to a value of 80/81; the C indicated by the copyright symbol has a value of 1/1; the C near the bottom has a value of 81/80 (fractal maps are consistent with regard to translational movements; a chess-like move such as “down four, back one” always changes the formula by the same factor for a given plane); FIG. 7 shows a 3×3 pattern centered around C1 that uses the 7M and 11N dimensions based on factors 7 and 11. A complete letter pattern that tessellates over the plane for the 7M and 11N dimensions would have a repeating 6 row pattern of arrays (with central letters D, C, Z, Y, X, E) for factor 7, and a repeating 2 column pattern of arrays for factor 11, thus requiring a 6×2 pattern. The illustration shows only a 3×3 pattern centered around C1 that illustrates neighbor relations along the dimensions 7M and 11 N. The drawing shows a four-dimensional k by l by m by n array. When the bold-face X, with value X11/8, is detected, an adaptive feedback signal is sent out to enhance spectral signals that may be detected at C1 (copyright symbol) and suppress signals at other sites (corresponding to other C's that are farther away). When boldface Z (Z7/4) is detected, the same adaptive feedback process occurs; FIG. 8 shows how information from harmonic overtones can be visualized as movement on the fractal landscape of harmonic space. Information from higher harmonics can be visualized as an alerting movement, information from middle harmonics as an identifying movement, and information from lower harmonics as a confirmatory movement; FIG. 9 shows that frequency discrimination can easily separate tones that are a “diatonic comma” apart (an 81/80 ratio); FIG. 10 shows how the relationship between vowel formants and other simultaneous tones can be ascertained by two distinct mechanisms. The mechanisms are shown to be complementary on the fractal map; FIG. 11 shows examples of vowel formants, redrawn from Peter Ladefoged, Elements of Acoustic Phonetics, Univ Chicago Press (1996); FIG. 12 shows F2 vs. F1 plots of the basic parameters of the major vowels of English, including the vowel quadrilateral and resonating tube models. Redrawn from Kenneth N. Stevens, Acoustic Phonetics, MIT Press, Cambridge, Mass. (1998); FIG. 13 is redrawn from Stevens to eliminate a semilogarithmic scale, and shows the average values for F1 and F2 formant frequency for vowels of American English for men and women (indicated by separate vowel quadrilaterals); FIG. 14 shows the F2 vs. F1 plot of vowel islands, showing their narrow shape stretching from lower pitch men's voices to higher pitch women's voices. For each formant of each vowel, there is a broad overlap with the range of frequencies of the formant of at least one other vowel, showing that vowels have no simple one-to-one relationship to formant frequencies; FIG. 15 shows on an F2 vs. F1 plot how the invention provides a better way of defining vowels, based on the simple ratios derived from fractal harmonic overtone mapping of overtones up to harmonic 12. The lines of slope easily characterize vowel islands by going through them to show central tendencies or by passing them tangentially to delimit boundaries. Proceeding in a clockwise direction across the top, all ratios from 11:1 to 7:2 are shown. Moving down the right side, selected ratios are shown that apply to the vowel islands of American English. Below the line labeled 3:2 would be musical ratios 4:3, 5:4, 6:5, 7:6, 8:7, 9:8, 10:9, and 11:10. Similar graphs for F2/F1 in other languages show that the vowel islands may have different central tendencies and boundary values. However, the ratios appear to be used as parameters in a similar fashion; FIG. 16 shows how points on the fractal map are used to specify the vowel [i]; FIG. 17 shows how points on the fractal landscape are used to specify [e]. Not illustrated because of space limitation are the ratios 11:3 (on target) and 7:2 (too narrow); FIG. 18 shows how the uniform output of consonant-vowel coarticulation can be explained by movement patterns on the fractal landscape without invoking hypothetical “loci” for consonants; FIG. 19 reviews the basic feedback mechanism of high resolution adjustment of input sensitivity (Process 1). As an example, a partially characterized fractal map (C) may lead to feedback that increases gain for a specific part of the fractal map that would be a consistent fit. Alternatively, there could be inhibition of input from harmonic fields that are inconsistent with an expected pattern; FIG. 20 reviews the basic feedback mechanism of adaptive control of output acoustics and phonology (Process 2). As an example, the fractal map could directly control sound output from a resonating tube with a constriction. For a typical sound like fricative, aerodynamic forces make it easier to adjust a constrictor to maximize the (turbulent) noise. Sound as input could be monitored via the fractal map, and any harmonic overtones that are detected could be used as an indication of direction and magnitude by which to change the constrictor. In general, adjustments could be made automatically in background noise or other specific auditory conditions; FIG. 21 shows how the fractal map could be used for information storage and pattern recognition. A multitude of consecutive fractal maps (indicated by a stack of forms) over a period of time could be analyzed for patterns (indicated by branching lines). The minimal nature of the fractal map would allow specific characteristic features in a sequence of fractal map data to be the working model or template that defines a word, sentence, or grammatical feature. Words and syllables could follow a consonant-vowel-consonant (CVC) pattern. Sentences or phrases could follow a subject-verb-object (SVO) pattern. Compound verbs and other grammatical feature could follow a “Verb 1, Verb 2” (V1V2) pattern; FIG. 22 shows how the same information storage and pattern recognition architecture could allow switching from one language-specific set of rules to another. The same process that allows this would potentially exhibit dynamical system behavior with possible chaotic behavior organized around “attractors.” For example, input could be identified as the word “we,” and adjustments for formants, words, and grammar patterns could be initiated, until input was re-identified as the French word “oui.”; FIG. 23 shows plausible frequencies obtainable from a 4620 Hz signal by simple counting circuits. Counting circuits are of the “one-two-three one-two-three” type. Combinations of counting circuits using the ratios 2:1, 3:1, 5:1, 7:1 and 11:1 can lead to a variety of frequencies, here calculated down to frequencies of about 40 Hz. (4620 Hz was chosen for ease of calculation; numbers in boldface are exact frequencies, in Hertz) The various subharmonics tend to fill only the lower right corner of the fractal map; FIG. 24 shows inputs from segments that are neighbors in the cochlear model (arrows) can be mapped to widely spaced points on a fractal map. This may result in uneven coverage. Each input is shown with its associated subharmonics. These subharmonics may overlap in various areas in the fashion of overlapping tiles (the lines and dots, representing subharmonics filling a corner of a fractal map like FIG. 23). Dotted lines illustrate that a portion of a fractal lattice can be chosen so that an area (between the dotted lines) closely resembles a similar area (immediately above one dotted line or immediately below the other dotted line), offset by a constant factor. Specifying the degree of similarity that will be tolerated allows us to define the size of a typical region that mirrors the map as a whole. The fractal map “rolls over” and repeats itself regularly across an extended fractal lattice. DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE Referring now specifically to the drawings, a system for fractal harmonic overtone mapping according to the present invention is illustrated in the Figures. Fractal harmonic overtone mapping has four essential elements, labeled A through D in FIG. 1. Fractal mapping manifests three types of signal processing illustrated by feedback analysis of FIG. 1. Sound input (Block A) is analyzed via harmonic fields of different sizes, with parallel processing of the information from numerous staggered fields. Harmonic field correlational data from Block A are accumulated in Block B, where multidimensional mapping takes place. The simple feedback loop from Block B to Block A (“Process 1” signal processing) provides dynamic control of input sensitivity, via harmonic fields of different sizes. Signals from Block B to Block C control sound output (“Process 2” signal processing). Feedback from Block C can be transmitted as an auditory signal to Block A which is then mapped to Block B, resulting in a two-step feedback loop that can provide adaptive acoustics for music and phonology for speech. Features from Block B over a period of time are stored sequentially in Block D (“Process 3” signal processing), resulting in recognizable patterns that may be analyzed categorically as words, grammar, and language information. Feedback from Block D can be directly applied by adjusting the properties of the map in Block B, using map-based rules to affect the other feedback loops that go through Block B, allowing for the possibility of dynamical systems behavior in which small differences in initial conditions may result in vastly different states. It is also possible for feedback from Block D to be applied to associated Block A or Block C processes, but directing feedback to the fractal harmonic overtone map would be more parsimonious, as it may encourage dynamical systems behavior such as chaotic “attractors” that allow novel but unstable patterns to develop. In addition to the four essential elements A, B, C, D from FIG. 1, a fifth essential element (a quintessential element) would be the mapping formula. Although more than five dimensions can be used for other purposes (see part 5), the paper's analysis of critical bands in human hearing, historical evidence from ancient music, and arguments from human evolution suggest that five dimensions are sufficient for speech and music. Assigning a point (j, k, l, m, n) to represent a “just intonation” exact ratio tone R according to the formula R=2j3k5l7m11n allows resonant signals to be analyzed and graphed multidimensionally over a “quantal” landscape of discrete, perfectly spaced points in an array. This mathematical array would be easily accommodated in electronic or other digital form. This formula can be used statically, to store speech data or to define precise points in representations of various musical scales, and also can be used dynamically, allowing us to encode speech and music features as a channel or data stream. However, in order to avoid confusion between notes with similar names but in different octaves, the descriptions and examples in this application are confined to a single octave with ratios in the interval from 1 to 2, in which we can map tones in four dimensions as points (k, l, m, n). Included in the scope of the invention are: 1. Any and every product embodiment of fractal harmonic overtone mapping, including virtual maps of harmonic fields; 2. Maps of frequency ratios, or maps of mathematical functions that duplicate the input, output, or content of such a map; 3. Maps of overtones arrangement that are indexed in two or more dimensions; map of harmonic overtone space, 4. Maps that encode correlations of frequency input and organizes output; 5. Analyzing sounds by scanning harmonics based on a fractal map; 6. Analyzing sounds as locations and movements on a fractal map; 7. A process for representing sounds in five dimensions and an algorithm for filtering and recognizing speech and musical features; 8. Any device with high resolution feedback due to selective amplification of certain harmonics;any device that exhibits adaptive behavior by spectrum analysis using precisely spaced co-incidence detectors; 9. Any genetic algorithm for speech or music that derives a multidimensional harmonic map; 10. Any algorithm for dynamical system behavior that uses sound input feedback and sound output feedback based on a common map; 11. Any high-resolution feedback other than simple analog feedback, especially if guided by any type of frequency ratios an array or any type of parallel processing involving ratios of fractal map feedback or filtering, of any type. 12. Any type of correlated feature output including parallel processing; and 13. Any process giving the ability to resolve different formants of the vocal tract due to fractal mapping. A preferred embodiment of fractal harmonic overtone mapping according to the invention would includes spectral representations with logarithmic frequency axis, such as a spectral envelope derived from a discrete Fourier transform, or created in an analog fashion. Provisions that reflect basic properties of signals, such as intensity, duration, pitch and timing of signals, are handled by encoding these parameters on the fractal maps, using wherever possible simple global parameters that are more resistant to high noise levels. In particular, increased amplitude of signal, or loudness, is preferably quantified or characterized by the number of areas affected. Parameters that encode essential aspects of attack, decay, sustain, and release are also an important aspect of fractal mapping. This is embodied by reducing the temporal evolution of a signal to a sequence of essential images that can be reconstructed from minimal data. Using a map as a representation for signals such as auditory signals as patterns of images including moving images or scaled images on a map that preserves self-similarity permits using the map as a timing standard. This allows the creation of auditory images in sequence that can represent a transient signal image. Another preferred embodiment is to use fractal mapping for a human-like in the range of sounds, including dichotic and diotic signals, and include phase information (generally available until the volley rate tops out at about 5000 Hz and above). Another preferred embodiment is to use an input signal is modeled a spectral representation such as a discrete Fourier transform or a logarithmic frequency spectrum. Another preferred embodiment is to use an input signal derived from speech sounds. Another preferred embodiment is to use an input signal derived from musical sounds, or a mixture of speech and music, or a mixture of other audio signals. Another preferred embodiment is to usan e input signal derived from signals of unknown origin. The invention exploits the gesture-like nature of adaptive feedback, allowing speech and music to be “subconsciously” analyzed by strategies such as hidden Markov models (HMM) and allowing models to analyze phonemes and resonances. By extension, this mapping is also a way of indexing words and of organizing grammatical rules and musical constructions. The way acoustic space is partitioned for a particular person would be a consistent, self-organizing map of multidimensional features, allowing more accurate voice prints and voice recognition. For example, vowels are recognized by their formants, i.e., a resonance of the vocal tract. Across wide range of languages, vowels vary but properties such as the ratio F1/F2 (the ratio between first and second formant frequency) and the F2 onset-F2 vowel ratios (the ratio between initial and plateau second formant frequency) generally fall into a consistent range. The articulatory system across diverse articulations adjusts consonant-vowel coarticulation to preserve feature of the output. Vowel formants vary tremendously but the ratio between formants suggests that certain features (ratios) act as boundaries or may act as central tendencies. This would allow similar sounds to be interpreted in different ways depending on different languages. The length of time it takes for a speech segment to plateau, probably to allow for processing time, may be language dependent, so different parameters may be needed for onset and decay of input elements over time. Similarly, time domain parameters would vary depending on the adjustments needed for acoustic output. Output of the fractal map is like a digital processor, not being based on the frequency spectrum, an analog of sound. Method would allow subconscious signal processing strategies to work like through hidden Markov models to further study psychoacoustics and more closely reproduce human speech. Speech features analyzed with categorical perception are interpreted differently than sinusoidal sound waves. This allows the process of adaptive feature extraction. A method according to the invention would allow music to be analyzed and modified and would provide a new compact coding scheme for audio information and a novel storage method for speech information. Since good quality music and speech require fractals, distortions would result from any modification. Another aspect of this invention is that it creates a dramatically improved model of the motor theory of speech perception by allowing the association of the gesture-like character of dynamic feedback with the motor output of speech. Reflexes that adjust hearing sensitivity take a certain finite time span to react, so that speech segments tend to “plateau” for the length of time that it takes for this to occur. In the same way, the motor patterns involved in speech take a certain time span to react, so the speaker tends to slow down to a pace that can be both heard and attended to with dynamic feedback, a feature that computer generated speech could find useful. Other applications would allow reframing of virtually all speech and musical parameters, allowing characterization of different resonances of the vocal tract, resulting in more accurate voice prints. More accurate neuromuscular models of speech would have many applications, from diagnostic (speech pathology) applications to computer speech production to computer speech reception. Other applications are possible, such as scanning harmonic fields, capturing transients, adding time delays, “windows of attention” while speech segments plateau and adding “gates” to reject signals below a certain threshold in specific focal areas. Fractal harmonic overtone mapping allows filtering to get rid of high pitch and low pitch noise by only allowing harmonic spectra. Other applications include adding back in the lowest formant into telephone audio, cancelling noise and adding back the correct formants, and providing a hearing aid that filters out nonspeech sounds to allow background noise suppression. Dynamic control could be extremely fast, enhancing some input while suppressing other input, for example, preventing toxic noise exposure. Another application is that of an electronic cochlea (in silico). Adaptive tuning may be provided that measures speed via the Doppler effect based on fractal harmonic overtone mapping. A five dimensional fractal Quintic scale based on 2, 3, 5, 7, 11 may be designed to train the ear and brain to respond to inputs like 11/7, 7/5 and 5/3. This scale would be based on the frequency ratio 35/33 between the twelve basic notes of a an octave, resulting in an octave that is slightly stretched. A method and apparatus for fractal harmonic overtone mapping of speech and musical sounds is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims. | <SOH> TECHNICAL FIELD AND BACKGROUND OF THE INVENTION <EOH>This invention relates to fractal harmonic overtone mapping of speech and musical sounds for high-resolution, dynamic control of input sensitivity, adaptive control of output acoustics and phonology, and for information storage and pattern recognition. Current strategies for computer speech recognition and voice analysis are generally based on processes that transform information derived from the frequency spectrum of sound. The primary tools in spectral analysis of sound are the Fourier transform and many variants. A large variety of mathematical functions such as inverse spectral (“cepstral”) and wavelet analyses have also been applied to speech perception. Current strategies for speech processing reflect the theory that sound is perceived in the inner ear tonotopically, with location along the cochlea correlating with frequency. A number of prior patents explain the current strategies for signal processing and their limitations. For example, U.S. Pat. No. 6,124,544 teaches that autocorrelation has proven unreliable. One reason that is mentioned is that the sample rate can introduce artifacts. U.S. Pat. No. 6,701,291 supports advantageously adjusting, in a coordinated manner, a handful of parameters. U.S. Pat. No. 6,584,437 reviews coding methods that use a lattice to encode pitch periods and differences between pitch periods. U.S. Pat. No. 6,658,383 explains how speech and musical signals are approached differently in the current art. A proposed solution is to encode signals with several modes, using different modes for musical signals and voiced speech signals. U.S. Pat. No. 6,658,383 does not, however, address unvoiced speech. U.S. Pat. No. 6,725,190 discloses various approaches to coding speech including a proposal for phase-binned speech but requires separate accounting based on a “voicing decision.” U.S. Pat. No. 6,745,155 discusses input from a “basilar membrane model device”, with time delays or autocorrelation as a means for signal analysis. U.S. Pat. No. 6,732,073 discloses a way of enhancing a frequency spectrum, using the history of sound signals a short interval before as well as information about sound signals a short interval afterward. The inclusion of information over time is a key aspect of many current approaches to signal analysis. Cochlea, the Latin word for “chamber,” is pronounced either as “coke”-lee-uh or as in the phrase “the cockles of the heart” (from the Latin cochleae cordis, “chambers of the heart”). Like the heart, it has a spiral shape (a “cockleshell”), which acts somewhat like a prism to separate sound into its various component frequencies. Frequency information is processed in the inner ear, which consists of the cochlea, the cochlear nucleus, and a variety of brain centers. There are three problems with a psychoacoustic model that uses only tonotopic frequency information. Critical bands, which limit our ability to hear frequencies that are too close together, indicate that there is a signal processing mechanism along the length of the cochlea that may provide contrast enhancement or automatic gain control. Experiments show that for typical tones, the fundamental and harmonic overtones 2 through 6 are perceived as distinct tones and higher harmonics are perceived as a fused “residue tone” or “residual tone.” Humans apparently can only be consciously aware of harmonic overtones that are far enough apart to fall into separate critical bands. Humans cannot hear harmonic overtones that are “too close together.” However, this does not preclude possible mechanisms that advantageously make use of information in higher harmonic overtones via unconscious processes. Signal processing via such “hidden Markov models” is a common theme in neural network modeling. “Active hearing” refers to recent advances in our understanding of the mechanism of hearing including the function of the protein prestin and the presence of a spectrum of self-reinforcing vibrations in the inner ear. These reverberations are due to positive feedback loops across the width of the cochlea involving outer hair cells and their stereocilia. Stereocilia act as valves that control the flow of charged ions (like transistors, controlling the flow of more power than they absorb, according to C. D. Geisler, From Sound to Synapse, Oxford Univ Press, 1998). When movement of an outer hair cell's stereocilia change its voltage, the protein prestin causes the cell to elongate or contract. (D. Oliver et al., Science 292, 2340, 2001). This rocks the cochlear partition, which triggers the cell's stereocilia, causing the cycle to repeat. In effect, each segment of the cochlea is a regenerative receiver. This is the historical term used for radio receivers that used positive feedback. They invariably had a regeneration control to vary the amount of positive feedback (Philip Hoff, Consumer Electronics for Engineers, Cambridge Univ Press, 1998). According to active hearing, when a sound is initially perceived there may be a gesture-like shift in the reverberations in the cochlea. Hearing a sound may force the cochlea to “tune in.” This type of process would be analogous to “adaptive optics” and would require dynamic feedback with a time scale estimated to be on the order of 0.5 ms. Thus, the function of the cochlea is more than a prism-like separation of sound into its component frequencies. Multiple maps of auditory space have been suggested by experiments involving researchers wearing distorting earpieces that disrupt their ability to judge whether sounds are “up” or “down.” (P. M. Hofman, J. G. A. Van Riswick, A. J. Van Opstal, Nature Neuroscience, 1 (5)417,1998). Unlike experiments with distorting eyeglasses, which take time for readjustment afterwards, correct sound localization occurred immediately when the fake ears were removed. Thus, shifting between cortical representations is possible, raising the question of how frequency information distributed along the cochlea (a one-dimensional analog) could be sufficient to model the three-dimensional world. An additional problem is how the complexity of multiple maps would be managed. Two innovationssolutions were developed by the author. The first is from the field of neural network signal processing and is the concept “harmonic fields.” The second is from the field of optimization theory and is an extension of the mathematical concept of an adaptive walk on a virtual landscape, “fractal mapping.” If the virtual landscape is a map of the neuromuscular patterns for sound in the throat and also the sensorineural patterns for sound in the ear, combined with the neural feedback for dynamic control of active hearing in the cochlea, optimization of the multiple interacting streams of data applying to different size scales but have similar recursive possibilities could occur. The result would be similarity and function across different size scales, leading the author to the concept “a fractal map of harmonic overtone space.” The invention was developed in the course of research for the paper, “Fractal harmonic reconstruction of ancient South Asian musical scales,” by Robert Patel Quinn, M. D. The invention is introduced as a method for analyzing harmonic overtones, which are high pitch sounds that have frequencies which are an exact multiple of the fundamental frequency. Although a frequency can be described both as a harmonic and as an overtone, the terminology employed in the paper distinguishes harmonics from overtones by using numbers for harmonics and letters for overtones, and uses the convention that harmonic 1 is the fundamental frequency of a tone. Musical notes are drawn as a column (a musical staff) with higher pitch harmonic overtones at the top and the fundamental at the bottom. In contrast to neural network signal processing models of the sense of touch and vision, which involve “receptive fields” that are spatially contiguous, the olfactory system processes smells by “molecular receptive range.” (K. Mori, Y. Yoshihara, Progress in Neurobiology, Vol 45, 585, 1995). An analogous process in the ear could correlate sounds an octave apart, leading to harmonic fields. Harmonic fields can be visualized ( FIG. 3 ) as a connection (a neuron) linking two points in the cochlea; for example, those that correspond to harmonics 9 and 3 . Another example of a harmonic field is shown by the neuron linking harmonics 3 and 1 . Each neuron would also function as a “sensor” for coinciding harmonics 6 and 2 of other tones with different fundamentals, reinforcing the linking relationship; the harmonic fields are detectors of the ratio rather than of specific numbers. Higher order connections between these neurons (“neural networking”) and signals flowing toward the brain as well as “active hearing” signals flowing toward the cochlea are important components of the fractal harmonic overtone mapping model. The hypothesized harmonic fields are scanned and the results are integrated into a multi-dimensional map. The illustration shows that sound first enters the inner ear at the high-frequency end of the cochlea. Depending on the speed of sound in the fluid of the cochlea and the speed and course of neural signals, this may be a reason that harmonics are scanned from high to low frequencies, although the spiral design of the cochlea tends to ensure that harmonics are perceived roughly simultaneously. A more fundamental reason why high frequency harmonics would be expected to be perceived first is the fact that the higher sampling rates possible at high frequencies would allow the wavelength of sound to be identified faster. “Inharmonic fields” would not be expected to develop. Unevenly spaced “inharmonic fields” would not be expected to develop naturally in the nervous system since reinforcement would not occur from inputs with a variety of fundamental frequencies if their harmonics were not appropriately spaced. If designed according to a genetic algorithm approach, efficiency suggests that some harmonic fields are redundant. An evolutionary approach would tend to produce enough complexity to exploit information but not too much for processing. The paper proposes the assumption that “harmonic fields develop only for tones that provide new information (the prime factors 2, 3, 5, 7, and 11).” This is because scanning through these prime number ratio harmonic fields (looking for simultaneous or near-simultaneous sounds) and then using other neurons to scan for simultaneous or near-simultaneous “higher order” correlations of neural network signals would result in information that can be recorded in a consistent fashion on a five dimensional fractal map. Information associated with ratios such as 4, 6, 8, 9, 10 or 12 would be included in the map, offset by an appropriate magnitude. It would be redundant to require separate dimensions to represent the same information. Prime-numbered fields would carry new information. The information from harmonic fields would constitute parallel channels (streams) of information. Parallel processing would allow hidden Markov models to solve the problems of phonology and segmenting the stream of speech. This is currently the major roadblock to current strategies for computer speech recognition and voice analysis which do not perform signal processing in terms of categorical features. The method section of the author's paper, “Fractal harmonic reconstruction of ancient South Asian musical scales,” opens with, “The basic idea of a fractal is that the same processes, or the same statistics or properties of a figure, are found at all size levels. In a fractal representation of multidimensional space each feature of the fractal represents a different axis and the range of values (magnitude) of each feature is plotted along that axis. Familiarity with the relationship between points on one or two axes gives familiarity with the relationships between points on all axes” (See to “B. Levitan; santafe.edu\nk.html.”) “We can map out a rectangular array using the first two factors, then for the next factor we add another array displaced horizontally, followed by a copy of the arrays displaced vertically. By alternating these steps as we add successive factors, we develop the recursive property that gives the representation its fractal nature.” These steps establish that a multidimensional map can be graphically represented in two dimensions. It should be noted that the cited online article by Bennett Levitan was an explanation of how he and Simon Pariser could graphically display various nucleic acid base pairs and the way they mutated to become codons for other amino acids. Although this is in a different field, the pattern of iterative steps (first left to right, then top to bottom, then left to right, etc.) was followed in constructing the fractal harmonic overtone map in order to establish a consistent convention. | <SOH> SUMMARY OF THE INVENTION <EOH>Therefore, it is an object of the invention to provide a fractal representation of harmonic fields and fractal harmonic overtone mapping for high-resolution, dynamic control of input sensitivity. It is another object of the invention to provide a fractal representation of harmonic fields and fractal harmonic overtone mapping for adaptive control of output acoustics and phonology. It is another object of the invention to provide a fractal representation of harmonic fields and fractal harmonic overtone mapping for information storage and pattern recognition for speech and music. These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing an apparatus for signal processing based on an algorithm for representing harmonics in a fractal lattice, the apparatus comprising a plurality of tuned segments, each tuned segment including a transceiver having an intrinsic resonant frequency the amplitude of the resonant frequency capable of being modified by either receiving an external input signal, or by internally generating a response to an applied feedback signal. A plurality of signal processing elements arranged in an array pattern. The signal processing elements include at least one function selected from the group consisting of buffer means for storing information, feedback means for generating a feedback signal, controller means for controlling an output signal, connection means for connecting the plurality of tuned segments to signal processing elements, and feedback connection means for conveying signals from the plurality of signal processing elements in the array to the tuned segments. According to one preferred embodiment of the invention, the tuned segments form a combined sensor unit arranged in a cochlea-like pattern. According to another preferred embodiment of the invention, individual ones of the signal processing elements include a neural-column structure having a plurality of layers, at least some of which layers are capable of functioning as counting circuits, selected from the group of counting circuits selected from the group of 2:1 counters, 3:1 counters, 5:1 counters, 7:1 counters, and 11:1 counters. According to yet another preferred embodiment of the invention, the plurality of signal processing elements are arranged so that an output from the counting circuits can be directed to counting circuits in other signal processing elements in order to generate a plurality of signals at subharmonic frequencies, each subharmonic frequency being associated with a separate signal processing element. According to yet another preferred embodiment of the invention, the fractal lattice includes guide means for guiding an organizational pattern for local sections of the array by performing at least one of the processes in a group of process steps consisting of establishing sensory and feedback connections between the signal processing element for a given frequency and the tuned segment having approximately the same characteristic frequency, generating a plurality of subharmonic signals that fall within the relevant frequency range of the tuned segments, and tentatively connecting these signal processing elements to the appropriate tuned segments, selecting unassigned tuned segments and tentatively connecting them to available signal processing elements at dispersed points in the array, approximately matching the intrinsic frequency of each tuned segment with signal processing elements that can create a rhythm generator for another local area of subharmonic frequencies, maintaining areas of overlapping subharmonics if their interacting counting circuits can be shared and are consistent, and removing the tentative connections if they are inconsistent, removing the tentative connections from elements in the array if their feedback goes to neighboring tuning segments that are too close together, so that similarly tuned neighboring segments become associated with signal processing elements that are widely spaced, and continuing until signal processing elements are connected to a sufficient number of tuning segments and a sufficient number of subharmonic generators have been organized to cover the array. According to yet another preferred embodiment of the invention, the optimal number of the tuned segments and the signal processing elements are determined by the degree of fine-grainedness and speed of acquisition of the input signal. According to yet another preferred embodiment of the invention, the optimal number of tuned segments and signal processing elements are determined by the degree of fine-grainedness and speed of the feedback response. According to yet another preferred embodiment of the invention, the number of dimensions in the fractal lattice and range of values in each dimension are determined by transceiver characteristics selected from the group consisting of sensitivity of input, specificity of input and feedback signals of the individual tuned segments. According to yet another preferred embodiment of the invention, the number of dimensions in the fractal lattice and range of values in each dimension are of a predetermined computational complexity. According to yet another preferred embodiment of the invention, the number of dimensions in the fractal lattice and range of values in each dimension are determined by processing speed. According to yet another preferred embodiment of the invention, the apparatus including means for selectively transmitting a plurality of feedback signals to adjacent tuned segments which would otherwise be subject to alternating constructive and destructive interference, wherein the feedback signals are selected from neighboring signal processing elements for minimizing interference beating. According to yet another preferred embodiment of the invention, the invention includes harmonic derivation means for deriving harmonically related signals of similar phase from subharmonic generators and using the related signals to add energy to various tuned segments by subthreshold strobing at the characteristic frequency of such segments. According to yet another preferred embodiment of the invention, the invention includes signal selection means for selecting signals of non-adjacent segments from signal processors elements to allow signals with different phases to be reinforced by differently-phased strobing feedback signals. According to yet another preferred embodiment of the invention, a method of signal processing based on an algorithm for distributed representation of signals, and of the harmonic relations between components of such signals, represented by a fractal lattice which includes multiple dimensions based on harmonic fields is provided, the method comprising the steps of mapping input signals to signal processing elements arranged in an array, processing signals to generate a plurality of feedback signals at subharmonic frequencies, combining the plurality of feedback signals with subsequent input signals. According to yet another preferred embodiment of the invention, the algorithm comprises EQ#R=2.sup.j*3.sup.k*5.sup.L*7.sup.m*11.sup.n. According to yet another preferred embodiment of the invention, the method includes the further step of providing additional harmonic information in an expanded fractal lattice reflecting a dimension selected from the group consisting of 13, 17, 19, and 23. According to yet another preferred embodiment of the invention, the method includes the step of simplifying the algorithm by removing one or more factors in order to allow a fractal lattice of a recorded dimension. According to yet another preferred embodiment of the invention, the method includes the step of modelling an input signal as a spectral representation selected from the group consisting of a discrete Fourier transform and a logarithmic frequency spectrum. According to yet another preferred embodiment of the invention, the method includes the step of deriving the input signal from speech sounds. According to yet another preferred embodiment of the invention, the method includes the step of deriving the input signal from the group consisting of musical sounds, a mixture of speech and music, and a mixture of audio signals other than speech, music or a mixture of speech and music. According to yet another preferred embodiment of the invention, the method includes the step of deriving the input signal from signals of unknown origin. According to yet another preferred embodiment of the invention, a computer readable medium is provided having instructions for performing steps according to the method. | 20040708 | 20080520 | 20050113 | 94707.0 | 0 | GODBOLD, DOUGLAS | FRACTAL HARMONIC OVERTONE MAPPING OF SPEECH AND MUSICAL SOUNDS | SMALL | 0 | ACCEPTED | 2,004 |
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10,887,288 | ACCEPTED | Open-loop electric current sensor and a power supply circuit provided with such sensors | An open-loop current sensor comprising a magnetic circuit having an air gap, a magnetic field detector disposed in the air gap, and a primary conductor having one or more turns surrounding the magnetic circuit, the current to be measured flowing in the primary conductor, the sensor being characterised in that the turns of the primary conductor are disposed close to the air gap, on each side of the air gap. | 1. An open-loop current sensor comprising a magnetic circuit having an air gap, a magnetic field detector disposed in the air gap, and a primary conductor having one or more turns surrounding the magnetic circuit, the current to be measured flowing in the primary conductor, the sensor being characterized in that the turns of the primary conductor are disposed close to the air gap, on each side of the air gap. 2. A sensor according to claim 1, wherein the turns of the primary conductor are disposed symmetrically on each side of the air gap. 3. A sensor according to claim 1, wherein the turns of the primary conductor comprise a U-shaped part stamped and mounted on a printed circuit. 4. A current sensor according to claim 1, wherein the turns of the primary conductor on each side of the air gap are connected in parallel. 5. A power supply circuit comprising semiconductor switches for generating a sinusoidal alternating current supplied on one or more supply lines of a load, such as an electric motor, and an open-loop current sensor disposed on each line, the open-loop current comprising a magnetic circuit having an air gap, a magnetic field detector disposed in the air gap, and a primary conductor having one or more turns surrounding the magnetic circuit, the current to be measured flowing in the primary conductor, the sensor being characterized in that the turns of the primary conductor are disposed close to the air gap, on each side of the air gap. | The present invention concerns an open-loop current sensor, in particular a current sensor for measuring current in power circuits or circuits supplying electric motors, as well as a supply circuit provided with such sensors. In modern supply circuits 106, as shown in FIG. 1, the supply current of the motor 105 is generated by semiconductor switches 103 switched at high frequency. The current I(t) actually generated typically has a frequency of a few tens of kHz, whilst the fundamental frequency If of the supply current, having a sinusoidal shape overall represented by the envelope of the current I(t), is relatively low, for example around a few hundreds of Hz, as illustrated in FIG. 2a. The technological advances achieved in the design of power semiconductors enable the switches 103 to have extremely high switching speeds, the potential variation speed dv/dt being for example around 10 to 20 kV/μs, as illustrated in FIG. 2b. In order to contain the electrical radiation caused by such potential variation speeds, use is made of coaxial cables 104 for supplying the motor 105. Since these cables are highly capacitive, and having regard to the dv/dt applied, stray high-frequency (HF) currents are generated in the form of oscillations damped at each switching. The amplitude and frequency of these currents are of the same order of magnitude whatever the driving power. This is because they depend practically only on the characteristics of the coaxial cables used and the amplitude of the dv/dt applied. The amplitude of these currents can reach several tens of amperes and their frequencies range from 100 kHz to 1 MHz. The current sensors 101 are generally placed on lines 102a, 102b, 102c supplying the motor 105. Although these HF currents do not have to be measured, they nevertheless pass through the current sensors. In drives 106 of small and medium power, the amplitude of these stray currents may be much higher than those of the currents necessary for controlling the motor. FIG. 2c shows, on an oscilloscope screen, the voltage U(t) and the high-frequency current I(t) due to the switchings and to the capacitive loads on one phase of a 5.5 kW motor supplied by a supply circuit switched at 16 kHz. In this example, the amplitude of the first and second half-wave I1,I2 is approximately 20 A and 8 A respectively. In practice an amplitude at the first half-wave I1 and I2 of 20 A and 30 A peak is normal. The inventors have realised that this causes two main problems. The first is an increase in the thermal current passing through the sensor, which can be resolved by sizing the sensor as a function of the sum of the rms currents which pass through it. Another problem is very great heating of the magnetic circuit due to losses by hysteresis and losses by eddy currents. It is necessary to emphasise that these problems are not found in sensors of the “closed loop” type since, to within any compensation errors, the primary ampere-turns (At) are compensated for by the secondary ampere-turns. It should be noted that the heating of the magnetic circuit will be all the higher, and therefore difficult, the smaller the size of the sensor. This is due to the sizing constraints with small open-loop current sensors. This is because, for reasons of measuring precision, it is not appropriate to design a sensor below a minimum level of 40 ampere-turns. This means that a sensor of nominal size 10 A will be designed with 4 primary turns whilst a 40 A nominal sensor can be designed with simply 1 primary turn. Thus, in the first case, the amplitude of the HF currents and the resulting magnetic induction will be multiplied by 4 compared with the second case and consequently the heating due to the losses by hysteresis and the dynamic losses will be 16 times greater, as can be deduced from the following relationship: Losses(w)≈f2B2d2/φ where d is the thickness of the magnetic plates, B is the magnetic induction, f is the frequency of the induction and therefore of the stray current HF and φ is the resistivity of the ferromagnetic alloy constituting the magnetic circuit of the sensor. Tests show that temperatures from 200° C. to 300° C., or even more, would be reached with open-loop sensors of small size and traditional construction if they were used as they stood in the applications described above. In practice, this type of sensor can be used only if there is disposed on its primary connections a related circuit which diverts the HF currents; however, this circuit has the drawback of destroying the dynamic performance of the sensor and thus restricts the efficiency of the drive. For these reasons, this type of sensor is not, up to the present time, used in drives for high-performance motors; it is replaced by a sensor of the more expensive “closed loop” type. In the light of the above, one aim of the invention is to produce an open-loop current sensor having the required dynamic performance and which can withstand high currents flowing in the primary conductor. Another aim of the invention is to provide a power supply circuit provided with such sensors. It is advantageous to produce an open-loop current sensor able to withstand stray HF currents generated by high potential variation speeds (dv/dt), as present in semiconductor switching circuits for supplying electric motors. It is advantageous to produce a compact and inexpensive open-loop sensor. Aims of the invention are achieved by an open-loop sensor according to claim 1 and a power supply circuit according to claim 5. The open-loop current sensor comprises a magnetic circuit having an air gap, a magnetic field detector disposed in the air gap, and a primary conductor, in which the current to be measured flows, having one or more turns surrounding the magnetic circuit. The open-loop current sensor is characterised in that in the turns of the primary conductor are disposed close to the air gap, on each side of the air gap. In this part of the magnetic circuit, the local permeability is much lower than in all the other parts of the magnetic circuit because of the presence of the air gap (μair=1). Because of the primary turns, the effective permeability of the magnetic circuit is much lower. Because of this, for the same primary ampere-turns value, the magnetic induction in the magnetic core (also referred to as the “iron”) is locally, but also overall, lower. Consequently the losses by hysteresis and by eddy currents are minimised. Other aims and advantageous aspects of the invention will emerge from the description, the claims and the accompanying drawings, in which: FIG. 1 is a schematic view of a circuit supplying electric current to an electric motor; FIG. 2a is a graphical representation of the current and the potential generated by the supply circuit on a phase connected to the motor; FIG. 2b is a representation in detail (enlarged) of the current and the potential generated by the supply circuit on a phase connected to the motor; FIG. 2c is a view of an oscilloscope screen showing the phase output voltage and high-frequency current due to the switchings and capacitive loads on a phase; FIG. 3 is a simplified view of a conventional open-loop current sensor showing the magnetic flux lines; FIG. 4a is a perspective view of an open-loop current sensor according to the invention; FIG. 4b is a perspective view of a variant of an open-loop current sensor according to the invention; FIG. 4c is a perspective view of a variant of an open-loop current sensor according to the invention; FIG. 5 is a graph showing the overvoltage V=L dI/dt at the terminals of the primary of a conventional sensor, and respectively of a sensor according to the invention; FIGS. 6a and 6b are graphs showing the change in the temperature in the magnetic circuit of a conventional sensor, and respectively of a sensor according to the invention on a line supplied by a sinusoidal current having a frequency of 200 kHz; FIG. 6a concerns a sensor with: eight primary turns with flowing through it a current of 5 A, that is to say 40 At; an iron-silicon magnetic circuit having an air gap 1.3 mm long and consisting of a stack of eight plates 0.35 mm thick; its cross-section is 9.8 mm2 and its average length measures 40 mm; FIG. 6b concerns a sensor with: twelve primary turns with flowing through it a current of 3.33 A, that is to say 40 At; an iron-nickel magnetic circuit, having an air gap 1.3 mm long and consisting of a stack of eight plates 0.35 mm thick; its cross-section is 10 mm2 and its average length measures 35 mm; and FIG. 7 is a graph of the output voltage Vout of a conventional sensor, and respectively of a sensor according to the invention, according to the ampere-turns. In known open-loop sensors, whatever the form of the magnetic circuit, the coil 110 (see FIG. 3) constituting the primary winding Np is normally placed on a sector, or on a branch 111 in the case of a rectangular magnetic circuit 112, situated directly opposite the air gap 113, as shown in FIG. 3. This location is actually the one which appears the most natural; it is also the one which appears the most logical from the point of view of practical implementation, since the primary winding can be more easily wound around the branch opposite to the air gap by passing the wire through the air gap. However, the inventors have realised that this location proves unfavourable. This is because, if attention is paid to the magnetic phenomena which result from this arrangement, it is found that, in the portion of magnetic circuit 111 enclosed by the primary coil 110, the magnetic induction flux Φ is much higher than in the rest of the circuit. This is due to the fact that, far from the air gap 113, the local permeability μr, seen from the point where the primary turns are placed, tends towards the value of that of the magnetic material used, and it will be recalled that Φ=B×S and B=μH and therefore Φ=μH×s, where B is the magnetic induction, S is the cross-section of the coil, H is the magnetic flux and μ the permeability. Moreover, because of the presence of the air gap, a major part of the magnetic induction flux generated by the primary ampere-turns (principal flux Φp) will close up on itself outside the magnetic circuit (dispersion flux Φd). The other part Φe closes up through the magnetic circuit and through the air gap 113 where the measurement is made by a magnetic field detector 114, such as a Hall cell. Thus more non-useful flux is generated than useful flux. The non-useful flux considerably increases the dynamic losses, the losses by hysteresis and the heating which results therefrom. With reference to FIGS. 4a to 4b, an open-loop sensor 1 according to the invention comprises a magnetic circuit 12 comprising a magnetic core having an air gap 13, an element for measuring the magnetic induction 14 comprising a cell for measuring the magnetic induction 15 disposed in the air gap, and a primary conductor 11 having one or more turns surrounding the magnetic circuit. The current to be measured lp (also referred to as the primary current) flows in the primary conductor. The measuring cell can for example be a Hall-effect sensor mounted on a printed circuit 16 of the measuring element, the circuit comprising conductive tracks connecting terminals 19 of the measuring cell to terminals 20 intended to be connected to an external measuring signal processing unit. The turns 21 of the primary conductor 11 are disposed around the magnetic core 12 on each side of and as close as possible to the air gap 13. The turns are illustrated as being in the form of turns of a wire. The turns can however take many other forms. For example (see FIG. 4c), the turns can be U-shaped conductors 21′, for example stamped metal sheet, surrounding the magnetic circuit 12 and connected for example to a printed circuit 22 provided with conductive tracks 23 connecting the U-shaped conductors. It should also be noted that two U-shaped conductors, one on each side of the air gap, can represent a single turn if they are electrically connected in parallel, for example by the conductive tracks on a printed circuit. In the part of the magnetic circuit close to the air gap, the local permeability is much lower than in all the other parts of the magnetic circuit because of the presence of the air gap (μair=1). Because of this, for the same value of primary ampere-turns, the magnetic induction in the material of the magnetic circuit is locally, but also overall, lower. Consequently the total losses and the heating which result therefrom are also lower. Moreover, the dispersion flux is also lower, since the magnetic induction is lower. There is thus a tendency to generate only useful flux. It should be stated that the induction in the air gap does not depend on the position of the primary turns, as is clear from the following explanation: An open-loop current sensor is an application of Ampere's theorem (I=∫ H·dL) which can be written, in the practical case of a magnetic circuit with air gap: Np×Ip=Hair×Iair+Hiron×Iiron however H=B/μ and therefore: Np×Ip=Bair×Iair/μo×μair+Biron×Iiron/μo×μr where Np is the number of primary turns, Ip is the primary current, Hair is the magnetic field flowing in the air gap, Iair is the length of the air gap, Hiron is the magnetic field flowing in the core of the magnetic circuit, Iiron is the length of the magnetic core, Bair is the magnetic induction in the air gap, Biron is the magnetic induction in the magnetic core, μair is the magnetic permeability in the air, μr is the magnetic permeability in the magnetic core and μo is a constant having the value 4 π 10−7. Knowing that the relative permeability of the air μair=1, and starting from the simplifying assumption that the induction in the air gap is equal to the induction in the iron, it is possible to write: Np×Ip×μo=B×(Iair+Iiron/μr) and Np×Ip×μo/Iair+Iiron/μr=Bair However, in our case, Iiron is small, whilst μr is very large (>100,000), and therefore the ratio Iiron/μr is negligible. Finally, the density of the magnetic flux measured by the Hall element in the air gap is: Bair=4 π 10−7×Np×Ip/Iair It should be stated however that it is practically impossible to calculate the induction values and therefore the total losses, in the case of a magnetic circuit with air gap, since the results depend on the geometric form of the magnetic assembly. Only the use of appropriate software and/or tests make it possible to evaluate the magnetic induction and the heating. FIGS. 6a and 6b are graphs showing the change in the temperature in the magnetic circuit of a conventional sensor, and respectively of a sensor according to the invention on a line supplied with a sinusoidal current having a frequency of 200 kHz. FIG. 6a concerns a sensor with: an iron-silicon magnetic circuit having a 1.3 mm long air gap and consisting of a stack of eight plates 0.35 mm thick; its cross-section is 9.8 mm2 and its average length measures 40 mm. FIG. 6b concerns a sensor with: an iron-nickel magnetic circuit having an air gap 1.3 mm long and consisting of a stack of eight plates 0.35 mm thick; its cross-section is 10 mm2 and its average length measures 35 mm. The sensor in FIG. 6a comprises eight primary turns with flowing through it a current of 5 A, that is to say 40 At. The sensor in FIG. 6b comprises twelve primary turns with flowing through it a current of 3.33 A, that is to say 40 At. In the case of the toroidal magnetic circuit according to FIG. 4b, it can be seen in the graph in FIG. 6a that, after 12 minutes operation, the temperature Tc of the magnetic circuit of the conventional sensor reaches approximately 136° C. (i.e. an increase of approximately 116° C.) whilst the temperature Ti of the magnetic circuit of the sensor according to the invention reaches approximately 78° C. (i.e. an increase of approximately 58° C.). The heating of a sensor according to the invention is therefore approximately half that in a conventional sensor with the same shape and dimensions. In the case of the rectangular magnetic circuit according to FIG. 4a, it can be seen on the graph in FIG. 6b that, after 12 minutes operation, the temperature Tc of the magnetic circuit of the conventional sensor reaches approximately 116° C. (i.e. an increase of approximately 96° C.) whilst the temperature Ti of the magnetic circuit of the sensor according to the invention reaches approximately 52° C. (i.e. an increase of approximately 32° C.). The heating of a sensor according to the invention is therefore approximately one third of that in a conventional sensor with the same shape and dimensions. Another advantage resulting from the sensor according to the invention is that the insertion inductance Lins of the sensor is lower. This is because: Lins=N2/Rm and Rm=I/μ×S where N is the number of primary turns, Rm is the magnetic reluctance, S is the effective cross-section of the air gap and I is the length of the air gap. However, in the sensor according to the invention, the permeability p is lower and the cross-section S also, since the flux is more even because of the position of the primary coil close to the air gap. By way of example, FIG. 5 shows the voltage U as a function of time for a current variation speed di/dt=40·106 A/sec U ( t ) = L ins ⅆ i ⅆ t obtained with a conventional sensor (curve Uc(t)) and a sensor according to the invention (curve Ui(t)) with the same shape and dimensions, both having a single primary turn. It is seen that, for the conventional sensor, the peak voltage Uc is 810 mV, which gives by calculation an insertion induction Lins of 0.02 μH, whilst for the sensor according to the invention the peak voltage Ui is 460 mV, which gives by calculation an insertion induction Lins of 0.0115 μH. Another advantage is that the cross-section of the magnetic core necessary for measuring a given current is lower because the magnetic induction in the core is lower, since the primary turns enclose a portion of the magnetic circuit where the apparent permeability is low. FIG. 7 shows that, with a sensor according to the invention, consisting of an iron-nickel magnetic circuit with approximately 80% nickel and a cross-section of 3.36 mm2, the current measurement is linear up to 188 At, whilst in a conventional sensor with the same shape, dimensions and quality the measurement of the current is linear only up to 88 At. In order to improve the sensor even further, it is possible to use a magnetic material for the core having low losses, such as for example iron-nickel alloys which have losses up to three times lower than those of the iron-silicon alloys normally used in these applications. Moreover it is possible to reduce the thickness d of the magnetic plates forming the core of the magnetic circuit. The most usual thickness in conventional sensors is 0.35 mm. The use of plates with a thickness of 0.2 mm can afford a reduction in losses by a factor of approximately three times. In summary, the open-loop sensor according to the invention disclosed above affords the following advantages in a simple manner: significant reduction in dynamic losses and losses by hysteresis significant reduction in the insertion induction of the sensors significant reduction in the cross-section of iron for measuring a given current, and therefore a reduction in the cost with regard to material. | 20040708 | 20070320 | 20050113 | 59155.0 | 0 | NGUYEN, TUNG X | OPEN-LOOP ELECTRIC CURRENT SENSOR AND A POWER SUPPLY CIRCUIT PROVIDED WITH SUCH SENSORS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,887,320 | ACCEPTED | Multi-protocol or multi-command RFID system | A multi-protocol RFID interrogating system employs a synchronization technique (step-lock) for a backscatter RFID system that allows simultaneous operation of closely spaced interrogators. The multi-protocol RFID interrogating system can communicate with backscatter transponders having different output protocols and with active transponders including: Title 21 compliant RFID backscatter transponders; IT2000 RFID backscatter transponders that provide an extended mode capability beyond Title 21; EGO™ RFID backscatter transponders, SEGO™ RFID backscatter transponders; ATA, ISO, ANSI AAR compliant RFID backscatter transponders; and IAG compliant active technology transponders. The system implements a step-lock operation, whereby adjacent interrogators are synchronized to ensure that all downlinks operate within the same time frame and all uplinks operate within the same time frame, to eliminate downlink on uplink interference. | 1. An interrogation system capable of communicating with transponders having different communication protocols, the interrogation system comprising; a plurality of interrogators, each interrogator having a transmitter for transmitting downlink signals in accordance with different communication protocols over a downlink communications link to the transponders, and a receiver for receiving an uplink signal over an uplink communications signal link from the transponders, and a synchronization signal for synchronizing the downlink signals for each of the plurality of interrogators. 2. The interrogation system of claim 1, wherein the transponders comprise a backscatter transponder. 3. The interrogation system of claim 1, wherein the transponders comprise active transponders. 4. The interrogation system of claim 1, wherein the transponders comprise active transponders and backscatter transponders. 5. The interrogation system of claim 1, wherein said plurality of interrogators comprise a first interrogator transmitting a first downlink signal in accordance with a first communication protocol and a second interrogator transmitting a second downlink signal in accordance with a second communication protocol. 6. The interrogation system of claim 1, wherein said synchronization signal synchronizes the downlink signals and the uplink signals so that the transmission of downlink signals do not interfere with the transmission of uplink signals. 7. The interrogation system of claim 1, wherein said synchronization signal synchronizes the downlink signals to end at substantially the same time. 8. The interrogation system of claim 1, wherein said synchronization signal synchronizes the downlink signals to start at substantially the same time. 9. The interrogation system of claim 1, wherein said synchronization signal synchronizes the downlink signals to start and transmit each bit at substantially the same time. 10. The interrogation system of claim 1, wherein said synchronization signal synchronizes the downlink signals so that the uplink signals start at substantially the same time. 11. The interrogation system of claim 1, wherein the synchronization signal synchronizes the uplink signals for each of the plurality of interrogators. 12. The interrogation system of claim 1, said interrogator further having a processor providing a trigger signal to the transponder, polling the transponder for specific information, and providing an acknowledge message to the transponder in response to a valid response to the polling message being received. 13. The interrogation system of claim 1, wherein said downlink signals comprise amplitude modulated radio frequency signals. 14. An interrogation system capable of communicating with backscatter transponders using a communication protocol having different commands, the interrogation system comprising; a plurality of interrogators, each interrogator having a transmitter for transmitting downlink signals in accordance with different commands over a downlink communications link to the transponders, and a receiver for receiving an uplink signal over an uplink communications signal link from the transponders, and a synchronization signal for synchronizing the downlink signals for each of the plurality of interrogators. 15. The interrogation system of claim 14, wherein said plurality of interrogators comprise a first interrogator transmitting a first downlink signal in accordance with a first command and a second interrogator transmitting a second downlink signal in accordance with a second command. 16. The interrogation system of claim 14, wherein said synchronization signal synchronizes the downlink signals and the uplink signals so that the transmission of downlink signals do not interfere with the transmission of uplink signals. 17. The interrogation system of claim 14, wherein said synchronization signal synchronizes the downlink signals to end at substantially the same time. 18. The interrogation system of claim 14, wherein said synchronization signal synchronizes the downlink signals to start at substantially the same time. 19. The interrogation system of claim 14, wherein said synchronization signal synchronizes the downlink signals so that the uplink signals start at substantially the same time. 20. The interrogation system of claim 14, wherein the synchronization signal synchronizes the uplink signals for each of the plurality of interrogators. 21. The interrogation system of claim 14, said interrogator further having a processor providing a trigger signal to the transponder, polling the transponder for specific information, and providing an acknowledge message to the transponder in response to a valid response to the polling message being received. 22. The interrogation system of claim 14, wherein said downlink signals comprise amplitude modulated radio frequency signals. 23. An interrogator capable of communicating with a first set of transponders and a second set of transponders, the first and second set of transponders having different power, depth of modulation, or duty cycles, the interrogator comprising: a transmitter for transmitting a first downlink signal to the first set of transponders and a second downlink signal to the second set of transponders; a receiver for receiving a first uplink signal from the first set of transponders and a second uplink signal from the second set of transponders; and, a controller for controlling said transmitter to transmit the first and second downlink signals based on the power, depth of modulation, or duty cycle of the respective first and second sets of transponders, and for controlling said receiver to receive the first and second uplink signals based on the power, depth of modulation, or duty cycle of the respective first and second sets of transponders. 24. The interrogator of claim 23, wherein said first downlink signal has a first power and said second downlink signal has a second power. 25. The interrogator of claim 23, wherein said first downlink signal has a first depth of modulation and said second downlink signal has a second depth of modulation. 26. The interrogator of claim 23, wherein said first downlink signal has a first duty cycle and said second downlink signal has a second duty cycle. 27. The interrogator of claim 23, said controller further synchronizing said first and second uplink signals and said first and second downlink signals. 28. The interrogator of claim 23, further comprising a voltage variable attenuator for adjusting the power of said first and second downlink signals. 29. The interrogator of claim 28, further comprising a power control unit having a high speed filter, a low speed filter, and a switch responsive to said controller for selecting said high speed filter or said low speed filter to provide a power level signal to said voltage variable attenuator to adjust the power of said first and second downlink signals. 30. The interrogator of claim 29, wherein said voltage variable attenuator and said power control unit form a closed loop. 31. The interrogator of claim 23, further comprising a modulation control unit having a high speed filter, a low speed filter, and a switch responsive to said controller for selecting said high speed filter or said low speed filter to adjust the depth of modulation of said first and second downlink signals. 32. The interrogator of claim 31, wherein said modulation control unit forms a closed loop. 33. The interrogator of claim 31, wherein the first set of transponders are active transponders and the second set of transponders are backscatter transponders. 34. The interrogator of claim 31, wherein the first and second sets of transponders are active transponders. 35. The interrogator of claim 31, wherein the first and second sets of transponders are backscatter transponders. 36. An interrogator having transmitter components for processing a transmit signal along a transmitter path, and receiver components for processing a received signal along a receiver path, said interrogator comprising: an encoder generating a test signal having bits and transmitting the test signal through each of the transmitter components along the transmitter path and through each of the receiver components along the receiver path; a decoder for receiving the test signal from a last component in one of the transmitter path or receiver path; and, a processor comparing the test signal generated by said encoder with the test signal received by said decoder, and determining that the transmitter and receiver components are operating properly if the test signal generated by said encoder matches the test signal received by said decoder. 37. The interrogator of claim 36, wherein the receiver components include a backscatter receiver for receiving signals from a backscatter transponder. 38. The interrogator of claim 36, wherein the receiver components include an active receiver for receiving signals from an active transponder. 39. An interrogator having receiver components for processing a received signal along a receiver path, said interrogator comprising: an encoder generating a test signal having bits; a test tag receiving the test signal from said encoder and transmitting a test signal to said interrogator for processing by the receiver components; a decoder for receiving the test signal from a last component in the receiver path; and, a processor comparing the test signal generated by said encoder with the test signal received by said decoder, and determining that the receiver components are operating properly if the test signal generated by said encoder matches the test signal received by said decoder. 40. The interrogator of claim 39, wherein the receiver components include a backscatter receiver for receiving signals from a backscatter transponder. 41. The interrogator of claim 39, wherein the receiver components include an active receiver for receiving signals from an active transponder. 42. The interrogator of claim 39, wherein the receiver components include an antenna. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to interrogatory systems. More particularly, the present invention relates to an interrogatory system having closely-spaced interrogators that simultaneously process different tag protocols or commands. 2. Background of the Related Art As discussed in U.S. Pat. No. 5,030,807 to Landt, RFID (radio frequency identification) systems use frequency separation and time domain multiplexing in combination to allow multiple interrogators to operate closely together within the bandwidth limitations imposed by radio regulatory authorities. In transportation and other applications, there is a compelling need for interrogators to operate in close proximity. In the example of a toll collection system, many lanes of traffic are operated side by side, and it becomes necessary to simultaneously read tags that are present in each lane. This introduces new challenges, particularly when a system is designed to communicate with tags of differing protocols, requiring performance sacrifices. Backscatter RFID systems, because they are frequency agile, can use frequency separation to allow simultaneous operation of closely spaced interrogators. However, the ability to operate with acceptable performance is limited by the ability of the interrogator to reject adjacent channel interference, and in the case where frequencies are re-used, co-channel interference. In addition, the interference impact of operating multiple interrogators in close proximity to one another is complicated by second and third order inter-modulation effects. Because the downlinks (interrogator to tag) are modulated signals and the uplink signals (tag to interrogator) are continuous wave (CW) carriers at the interrogator, the interference on an uplink by a downlink is more severe in most cases than either downlink on downlink interference or uplink on uplink interference. When downlink on uplink interference debilitates performance beyond an acceptable level, the system could be set up for time division multiplexing among the interrogators. Interrogators would then share air time (take turns) according to a logic scheme to minimize or eliminate the impact of the interference between interrogators. That, however, results in lower speed performance since a given transaction requires more total time to complete. When a large number of lanes are involved, the speed performance loss can be severe and unacceptable. Active RFID systems typically cannot use frequency separation due to the fact that cost-effective active transmitters operate on a fixed frequency. These systems have therefore followed an approach of operating in a pure time division mode to prevent interference among closely located interrogators. Downlink on downlink interference typically occurs when a tag receives the signals from two interrogators. If the interrogators are closely spaced, the RF level of the two transmitted bit streams may be comparable. If significant RF from the adjacent interrogator is received during bit period when none should be received, the tag may incorrectly decode the message. From a self-test perspective, RFID systems typically utilize what is commonly known as a “check tag” to provide a level of confidence regarding the health of the RFID system. The check tag can be an externally powered device that responds only to a specific command or responds only to its programmed identification number. It can be built into the system antenna or it can be mounted on or near the system antenna. It can also be housed within the interrogator and coupled to the system antenna via a check tag antenna mounted near the system antenna. Though the check tag can take a variety of forms, one commonality is that the check tag must be activated in some manner so that the response can be read by the interrogator and remain inactive during normal operation. When a check tag is activated, it typically provides a response that can be read by the interrogating device. The check tag response is generally the same as what would be received by the interrogator during normal operation as a tag passes through the system in that particular application. If a backscatter RFID system initiates a check tag and a response is received, it verifies the RFID system is operational to the point that RF has been transmitted and the check tag backscatter response received and decoded. Encoded modulation of the RF is only verified if the check tag requires a modulated signal to trigger its response. The time that it takes to complete the cycle depends upon the type of tag utilized and can range from a few to several milliseconds, and the cycle is repeated periodically. SUMMARY OF THE INVENTION It is therefore one object of the present invention to provide an interrogating system that is able to simultaneously operate a plurality of closely-spaced interrogators. It is another object of the invention to provide an interrogating system that synchronizes a plurality of interrogators. It is another object of the invention to provide a system that simultaneously processes different protocols used to communicate with tags. It is another object of the invention to provide a system that simultaneously processes different backscatter protocols. It is yet another object of the invention to provide a system that simultaneously processes different active and backscatter protocols. It is yet another object of the invention to provide an interrogating system that avoids interference on an uplink by a downlink, as well as downlink on downlink interference, and uplink on uplink interference. It is yet another object of the invention to provide a self-test operation that can verify operation of the interrogator and that does not have the time constraints of the check tag. It is another object of the invention to provide an interrogation system in which uplink signals are received, and downlink signals are sent, over a single antenna. In accordance with these and other objects of the invention, a multi-protocol RFID interrogating system is provided that employs a synchronization technique (step-lock) for a backscatter RFID system that allows simultaneous operation of closely spaced interrogators. The interrogator can read both active and backscatter tags more efficiently when combined with time division multiplexing. The multi-protocol RFID interrogating system can communicate with backscatter transponders having different output protocols and with active transponders, including: Title 21 compliant RFID backscatter transponders; IT2000 RFID backscatter transponders that provide an extended mode capability beyond Title 21; EGO™ RFID backscatter transponders, SEGO™ RFID backscatter transponders; ATA, ISO, ANSI AAR compliant RFID backscatter transponders; and IAG compliant active technology transponders. The system implements a step-lock operation, whereby adjacent interrogators are synchronized to ensure that all downlinks operate within the same time frame and all uplinks operate within the same time frame. The step-lock operation allows for improved performance with higher capacity of the RFID system. Active and backscatter technologies are implemented so that a single interrogator can read tags of both technology types with minimal interference and resulting good performance. The step-lock operation eliminates downlink on uplink interference. Because downlink on uplink interference is the most severe form of interrogator-to-interrogator interference, that has the net impact of reducing the re-use distance of a given frequency channel significantly. The step-lock technique can be extended to reduce or eliminate downlink on downlink interference for fixed (repeating) downlink messages. This can be achieved by having the interrogators transmit each bit in the downlink message at precisely the same time. Depending on radio regulations and the number of resulting available frequency channels with a given backscatter system, that can allow re-use distances sufficiently close that an unlimited number of toll lanes can be operated without any need to time share among interrogators, drastically improving performance and increasing capacity of the overall RFID system. Step-locking of the interrogators allows the interrogators to operate in a multi-protocol mode, whereby the same interrogator can read both active and backscatter tags in a more efficient way. This is accomplished by combining a time division strategy for active transponders and the step-locked frequency separation strategy for backscatter tags into one unified protocol. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a block diagram of interrogators in a step-lock configuration where the synchronization signal is generated by the interrogator in a Master/Slave mode; FIG. 2 is a block diagram of interrogators in a step-lock configuration where the synchronization signal is generated by an external source; FIG. 3(a) is a timing diagram of the step-lock feature showing the uplinks, downlinks, and processing times for multiple interrogators; FIG. 3(b) is a timing diagram at the bit level; FIG. 3(c) is a timing diagram of the step-lock feature having a time division multiplex; FIG. 4 is a preferred block diagram of the interrogator; FIG. 5 is a block diagram of the synthesized sources 33, 45 of FIG. 4; FIG. 6 is a block diagram of the dual mixer configuration 56 of FIG. 4; FIG. 7 is a block diagram of the DOM DAC and modulation control 60 of FIG. 4; FIG. 8 is a block diagram of the power amplifier 65 and its peripherals of FIG. 4; FIG. 9 is a block diagram of the downlink/uplink DACs and power control 72 of FIG. 4; FIG. 10 is a block diagram of the interrogator showing the loop-back built-in-test capability; FIG. 11 is a block diagram of the interrogator showing the test tag built-in-test capability with a coupling antenna; FIG. 12 is a block diagram of the interrogator showing the test tag built-in-test capability with a directional coupler; FIG. 13 is a lane plan for the system showing the downlink frequencies for a single protocol having different command sequences; FIG. 14 is a lane plan for the system of FIG. 13, showing the uplink frequencies; FIG. 15 is a timing chart for the system of FIGS. 13 and 14, showing the command sequences; FIG. 16 is a lane plan for the system showing the downlink frequencies for active transponders and backscatter transponders; FIG. 17 is a lane plan for the system of FIG. 16, showing the uplink frequencies; FIG. 18 is a timing chart for the system of FIGS. 16 and 17, showing the protocol sequences; FIGS. 19 and 20 are lane plans for the system showing the downlink and uplink frequencies for active transponders and backscatter transponders; and, FIG. 21 is a timing chart for the system of FIGS. 19 and 20, showing the protocol sequences. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the following detailed description of the preferred embodiment, reference is made to the accompanying drawings that form a part hereof and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. Turning to the drawings, FIG. 1 is a block diagram of the overall system 10 in accordance with a preferred embodiment of the invention. The system 10 depicts a single cluster of interrogators 12 and hosts or controllers 14 in a step-lock configuration, and various active or backscatter transponders 11. As shown, the interrogators 12 communicate with the transponders 11 in accordance with various tag protocols, Tag Protocol 1 and Tag Protocol 2. The controller 14 controls and interfaces various system components, such as the associated interrogator 12, vehicle detection, and video enforcement, as may be required by the specific application. One interrogator 12 is designated as the master, while the rest of the interrogators 12 are designated as slaves. The master interrogator 12 generates a synchronization signal 16 and transmits it to the slave interrogators 12. The interrogators 12 are connected together via an RS-485 interface for multipoint communication in half-duplex operation, and the synchronization signal 16 is transmitted over that line. The overriding factors in master/slave designation are the timing parameters set in the respective interrogators 12 versus the reception of the synchronizing signal 16. The timing parameters are set in each interrogator 12, such that the subsequent slave can become the master in the event of a failure. The interrogator 12 preferably has a single antenna 18 that is used to transmit the modulated downlink signal to interrogate a transponder 11. The single antenna 18 also transmits the CW uplink signal required to receive the backscatter response of a backscatter transponder. In addition, the single antenna 18 receives the response from an active transponder 11. FIG. 2 is a block diagram of the system 20, showing interrogator clusters 22 and associated hosts or controllers 24 in a step-lock configuration. An external source 26 is provided that generates the synchronization signal 28. In the preferred embodiment, the external source 26 is a GPS receiver that has a 1 pps (pulse per second) signal that is utilized to enable synchronization of the respective clusters 22. The master interrogator locks a reference clock to the GPS 1 pps signal, and uses the reference clock to generate the synchronization signal that is sent to the slave interrogators. The timing of the 1 pps signal from a GPS unit is very precise, which allows each of the clusters to be synchronized together in time. This configuration is utilized when distance, or some other physical impediment, does not allow for a direct connection of the clusters 22. Generally, one GPS receiver is required per cluster 22, and the interrogators 22 can then be connected as shown in FIG. 1 to synchronize the cluster to the external source. FIG. 3(a) is a timing diagram showing several interrogators 10 operating in step-lock. The diagram shows that all of the interrogators 12 transmit their uplink and downlink signals at the same time. When interrogators 10 are step-locked, the timing for each interrogator 10 is controlled so that the uplinks and downlinks all start and end at the same time. That reduces interference caused by one interrogator's downlink signal interfering with another interrogator's uplink signal. By utilizing different frequency plans among the various tag protocols, the number of interrogators in a particular cluster can be increased. As shown in FIGS. 1-2, the system polls a Title 21 backscatter transponder for specific information, and then polls an EGO backscatter transponder for specific information and the respective transponders respond accordingly. Each interrogator 12 transmits a Tag Protocol 1 signal and Tag Protocol 2 signal to each of the transponders 11. The Title 21 backscatter tags 11 provide a backscatter response to the corresponding Title 21 protocol signal, Tag Protocol 1, and the EGO backscatter tags 11 provide a backscatter response to the corresponding EGO protocol signal, Tag Protocol 2. FIG. 3(a) shows the timing required to support two tag protocols. As depicted, the first tag protocol, Tag Protocol 1, has downlink and uplink periods that differ from the downlink and uplink durations of the second tag protocol, Tag Protocol 2. The tag protocols may also have different processing times that follow the uplink of data. Thus, if the tag protocols are left unsynchronized, there is the strong potential that the downlink for either the first or second protocol of one interrogator would interfere with the uplink for either the first or second protocol of another interrogator. To avoid that interference, the interrogators are step-locked so that the downlinks of the first tag protocol end at the same time for all of the interrogators, and the downlinks of the second tag protocol also end at the same time for all of the interrogators, as shown in the figure. The timing is controlled by a synch signal at the beginning of each cycle, which triggers the downlink signal of Tag Protocol 1. If only those two types of tags are being interrogated, then the signal pattern in FIG. 3(a) would repeat itself. If more tag protocols are used, then the uplink and downlink signals for the additional tags are transmitted before the pattern is repeated. In some cases, a particular tag protocol may be transmitted multiple times before the interrogators switch to a different protocol, such as if the tag needs to be read multiple times or if the tag is read and then put to sleep by an additional command. Thus, the protocols are preferably implemented in a serial fashion, whereby each interrogator cycles through the various protocols before repeating the pattern and all the interrogators are processing the same protocol. That is, the downlink and uplink signals for Tag Protocol 1 are processed by all of the interrogators at the same time, followed by a processing time and the downlink and uplink signals for Tag Protocol 2. It should be apparent to one skilled in the art that the protocols need not be aligned in a serial fashion, but can be run simultaneously in a parallel fashion by synchronizing the downlink times across the different protocols. That is, a first interrogator can process a first protocol downlink signal while a second interrogator processes a second protocol downlink signal. This type of step-lock is illustrated with respect to commands of a single protocol, for instance, in FIG. 18, which is discussed below. However, having the interrogators process the same protocols minimizes any delay between the various signals due to the different signaling durations of the various protocols. For instance, if Interrogator 1 processes Tag Protocol 1 and Interrogator 2 processes Tag Protocol 2, a delay would have to be introduced before the downlink of Tag Protocol 1 since the downlink of Tag Protocol 2 is much longer, so that Tag Protocol 1 is not uplinking while Tag Protocol 2 is still downlinking. As shown in FIG. 18, the time for each transmission is increased to allow for the longest command, which is the select or read command of the EGO protocol. FIG. 3(b) is a diagram showing the step-lock technique extended to the bit synchronization level for the signals of FIG. 3(a). Each interrogator is step-locked and the transmission of each bit in the downlink message is transmitted at precisely the same time. For bit synchronization, the exact same command (bit for bit) has to be transmitted by each interrogator and is intended for protocols that satisfy that criteria. FIG. 3(c) shows the timing using a time division multiplexing and step-lock synchronization for an application that includes both active and backscatter transponders. The synch signal initiates the signal cycle, which in this case starts with the first set of interrogators, Interrogators 1, 4, 7, generating a transmit pulse in accordance with Tag Protocol 1, the active tag protocol. The active protocol is sent in accordance with a time division multiplex scheme. The transmit pulses are offset to prevent interference that corrupts data received by the reader which might otherwise result from closely located tags. Accordingly, the active protocol is divided into three time slots. In the first slot, the first interrogator and every third interrogator transmit the downlink for the active tag protocol. Following the transmission of the downlink, every interrogator looks for a response from the tag. If an interrogator that transmitted the downlink receives a response, that interrogator assumes that the tag is under its antenna. If an interrogator that did not transmit the downlink receives a response, that interrogator assumes that the tag is under the antenna of a different interrogator. The interrogator will preferably ignore responses of tags that under the antenna of a different interrogator. In the second and third time slots, the other interrogators transmit in their respective slots, and each interrogator uses the same logic on the received signals to decide if a tag response is under their antenna. Following the completion of the active tag protocol, every interrogator transmits the backscatter protocol downlink, and then looks for the backscatter uplink signal from the tag. Interrogators The multiple protocols supported by the interrogator translate to the specific requirements of the respective transponders. The tags can be passive or active, battery or beam powered, with additional variables that are dictated by the physics of the transponder. Thus, the interrogators 12 must be able to accommodate the different variables and requirements for active and passive tags, as well as the different commands and backscatter protocols. In addition, the interrogators 12 must be capable of adjusting itself to handle different protocol power levels, depths of modulation, duty cycle, speed (bit rates), frequency of transmissions, receiver range adjustments, as well as tag and interrogator sensitivity. Since the interrogator controls the power of the signal reflected by a backscatter transponder, the uplink RF power level is utilized to set the respective uplink capture zone for a backscatter transponder. The downlink RF power level is used to communicate with a transponder that requires a modulated command (Title 21, IT2000, EGO, SEGO backscatter transponders), or a trigger pulse (active transponder), before the device will respond. Thus, the RF downlink power is utilized to establish a downlink capture zone for the transponders specified, and in the case of backscatter transponders, can be different than the uplink RF power level. In addition, the RF power level required by a beam powered transponder is much greater than that required by a battery powered transponder. Closed loop control is implemented to maintain tight control of the dynamic RF power level that is required by the system. The requirement to support multiple depth of modulation (DOM) levels is necessary due to the fact that the transponder receiver dynamic range is dependent upon the DOM transmitted during the downlink. The base band path of the respective transponders can be AC or DC coupled where the DC coupled path typically requires a larger modulation depth. Closed loop control is implemented to maintain control of the dynamic DOM level from protocol to protocol. The ability to adjust duty cycle provides the flexibility to compensate for finite non-linearity in the interrogator modulation path and the capability to optimize the duty cycle to the respective transponder requirements. The duty cycle would typically be set at 50% with a small tolerance, however, the ideal for a transponder type could be higher or lower. The adjustment of the duty cycle or pulse width aids in the tuning of the modulated signal to the transponder requirements and in the derivation of transponder sensitivity to variations of duty cycle. With the exception of the Title 21 and IT2000 protocols, the baud rates are different for all the protocols. The ratio from the fastest protocol to the slowest protocol is in excess of 10-to-1. The interrogator must accommodate the different baud rates from the point of origin within the interrogator through transmission while maintaining control of RF power, DOM and the emission mask. The frequency of transmission, and when to actually transmit, relates to the synchronization period and must be variable in order to accommodate all combinations of protocols and command sequences. Finite receiver adjustments provide the capability to vary the sensitivity level of the interrogator for each protocol. Ideally, the default would be to have the interrogator sensitivity level of each protocol approximately the same. In a multi-mode application that requires the sensitivity levels of respective protocols to be different, they can be adjusted accordingly. An example is a multiple protocol application with a beam powered transponder of one protocol and a battery powered transponder of another protocol. The capture zone of the battery powered transponder can be adjusted to a certain degree by the level of RF transmitted. The same is true for the beam powered transponder, but to a much lesser degree. If it is desired to align the capture zones, the receiver adjustment provides another degree of freedom. This adjustment is provided for the RF receive path and in the form of threshold levels in the base band receivers that must be exceeded for the signal to pass. This technique is also useful for the elimination of undesirable cross lane reads. FIG. 4 is a preferred block diagram of the interrogator 12. The interrogator 12 has a transceiver 30, and a processor 100. The transceiver 30 provides the communications link to the transponder, and the processor 100 provides the functional control of the interrogator 10. The transceiver 30 is comprised of a transmitter chain that generates the amplitude modulation (“AM”) and CW carriers, a receiver to accept and process either the backscatter or active response of the respective transponder, and a controller to interface to the processor and provide the necessary control for the transmit and receive functions. The transceiver 30 includes a transmitter chain and a receiver chain. The transmitter chain includes sources 33, 45, source select 44, MOD/CW 56, RF AMP 65, filter 74, coupler 76, isolation 77 and coupler 78. The receiver chain includes filter 82, attenuator 84, select 86, receivers 88, 92, baseband processor 94, and detectors 90, 96. Transmitter The transmitter chain begins with the generation of two synthesized RF sources, the downlink/uplink source 45 and the dedicated uplink source 33. The sources 33, 45 are used to generate the uplink and downlink signals, such as the ones shown in FIG. 3(a). A downlink/uplink source 45 generates the first synthesized RF signal (S1), which is used as a downlink modulated source to interrogate, activate, and/or trigger a transponder. This source can also be used as an uplink continuous wave (CW) source to provide the communications link for the response of a backscatter tag. The uplink source 33 generates a synthesized RF source (S2), which is used as an uplink CW source to provide the communications link for the response of a backscatter tag. The sources 33, 45 are synthesized low phase noise sources that aid in providing high backscatter receiver performance with a single antenna. Turning to FIG. 5, the sources 33, 45 include a frequency synthesizer 34, loop filter 36, low phase noise voltage controlled oscillator (VCO) 38, and a coupler 40. The coupler 40 has a gain block 39 to feedback the VCO 38 output back to the synthesizer 34 to comprise a low phase noise phase lock loop (PLL). The output of the PLL has a high isolation buffer amplifier to provide gain and isolate the PLL from the transmitter chain. The processor 100 initializes the S1 and S2 sources to fixed frequencies through the controlling device 43 on the transceiver 30 via the Clock, Data and Load signals. An adjustable oscillator (not shown) provides the reference signal for both the uplink synthesizer 33 and the downlink/uplink synthesizer 45. The oscillator is adjustable to provide the capability to calibrate to an external standard reference. Source selection circuitry 44, comprised of high isolation single-pole, single-throw (SPST) switches, is used for sources 33, 45 that feed into a high isolation single-pole, double-throw (SPDT) non-reflective switch. That provides the ability to select either source 33 or 45, while maintaining a high degree of isolation between the sources 33, 45 to minimize the generation of inter-modulation products. The processor 100 controls the state of the switches through the controlling device 43 on the transceiver 30. A local oscillator (LO) 48 for the direct conversion backscatter receiver is coupled off of the output of the SPDT switch 45. It is fed into a high isolation buffer amplifier (not shown) to provide gain and isolate the transmitter chain from the receiver-portion of the transceiver 30. The LO level is fixed by a gain block, low-pass filtered and fed into a high isolation SPST switch (not shown) to provide additional isolation from the active receiver. The processor 100 controls the state of the SPDT switch of the source 45 through the controlling device 43 on the transceiver 30. The MOD/CW block 56 provides the capability to modulate the respective source or place the source in a CW condition. As shown in FIG. 6, the MOD/CW block 56 is comprised of a dual mixer configuration separated by a gain block. That configuration provides a high dynamic range of linear AM modulation to aid in reducing the transmitted occupied bandwidth. Though this type of configuration can introduce non-linear second-order effects, utilizing the second mixer to provide the majority of the AM modulation minimizes the distortion. The mixers 56 are driven at base band with the respective protocols bit stream, trigger signal or DC level, respectively, by amplifiers that provide the required drive levels. The drive levels from the amplifiers produce the desired peak level for CW or the “high” and “low” condition when modulating. Transmitter Bit Rate and DOM Adjustment The difference between the respective data rates of the protocols requires a configuration that can support the data rates for all of the protocols, while maintaining an emission mask that minimizes channel spacing in order to maximize the number of available channels. Bit rate adjustment is handled in the interrogator, FIG. 4, by the modulation control block 60, which is shown in greater detail in FIG. 7. The DOM DAC & Modulation Control 60 utilizes a switch to select between the high-speed path and the low-speed path. The high-speed path accommodates the high-speed protocols, such as Title 21 and IT2000, and a low-speed path accommodates the low-speed protocols, such as EGO, SEGO and a trigger pulse. The controlling device 43 on the transceiver 30 selects the desired path based on the protocol configuration indicated by the processor 100. Eighth-order low-pass filters provide the desired emission mask for the supported protocols. The control unit 60 receives a fixed DC reference level (VREF), which sets the level that indicates the transmission of a “high” bit, or CW condition as required, and is the same for all protocols. A digital-to-analog converter (DAC) 70 sets the level that indicates the transmission of a “low” bit, or the DOM (depth of modulation) level, which is retrieved from a memory in the controller 43 as required. The Modulation signal provides true logic control of an SPDT switch that selects either the “high” condition or the “low” condition based on the state of the Modulation signal. Each protocol that requires a modulated downlink transmission from the interrogator has a corresponding memory location in the controlling device 43 on the transceiver 30 that is calibrated to the DOM level required for that protocol. Switching between the respective DOM levels is handled by the controlling device 43 based on the protocol configuration indicated by the processor 100. The modulation control unit 60 outputs a Filter Mod signal, which is used by the MOD/CW 56 to modulate the signal in accordance with the desired protocol. Transmitter Power Level Adjustment The interrogator must also be able to accommodate the various power levels required by the various backscatter protocols and the active transponder protocol. Power adjustment is handled in the interrogator, FIG. 4, by the RF AMP 65 and the power controller 72, which are shown in greater detail in FIGS. 8 and 9. Turning to FIG. 8, the RF AMP 65 is comprised of a gain block 64, voltage variable attenuator 66, RF switch, and a 900 MHz Integrated power amplifier 68. The gain block 64 provides the desired level into the voltage variable attenuator 66. The voltage variable attenuator 66 is utilized to vary the RF power based upon a VCTL Attn signal received from the power controller 72. The attenuator 66 provides a fixed rise time when turning on RF power for CW transmission and also to the DOM level prior to a modulated transmission. The DL/UL DACs & Power Control 72 is shown in FIG. 9. A downlink DAC 71 sets the RF peak power level required for a downlink transmission to a transponder. An uplink DAC 73 sets the RF power level required for an uplink transmission of CW for a response from a backscatter transponder. Selection between the low-pass filtered uplink and downlink levels is handled by the Attn_Sel signal through an SPDT switch. Another SPDT switch passes the selected DAC level or a preset reference level as the VCTL Attn signal, which is utilized to limit the dynamic range of the voltage variable attenuator 66. Both the downlink and uplink power levels are calibrated independently to provide 15 dB of dynamic range in 1 dB steps. Each protocol requiring a downlink transmission from the interrogator has an independent memory location in the controlling device 43 to store the static power level for the respective configuration. The same is true for each protocol that requires an uplink transmission. The controller 43 controls the sequence of the downlink and uplink transmissions based on the protocol configuration and discrete inputs from the processor 100. The integrated power amplifier 68 is selected to provide the maximum desired output at the RF port while maintaining a high degree of linearity. The RF switch is utilized to provide the necessary OFF isolation when the active receiver is enabled. Transmitter Signal Processing A low-pass filter 74, coupler-isolator-coupler configuration 76, 77, 78 completes the transmitter chain. The low-pass filter 74 attenuates harmonic emissions. The first RF coupler 76 provides the feedback necessary for closed-loop control. The coupled signal from the coupler 76 is fed into a 4-bit digital step attenuator 97 that provides 15 dB of dynamic range in 1 dB steps. By providing the dynamic range in the power control feedback path, the closed loop control of downlink and uplink RF output power is simplified and accuracy of the transmitted power level is improved. The 15 dB feedback attenuation range coincides with the 15 dB dynamic range of the transmitter to set the respective power level for the downlink or uplink transmission. The feedback attenuator is set such that the attenuation level set on the uplink or downlink transmission, plus the level set on the digital step attenuator 97 in the feedback loop, always add up to 15 dB. That minimizes the dynamic range of the signal after the digital step attenuator 97 to the highest DOM level required by the supported protocols. The attenuator 97 output is fed into a logarithmic RF power detector 98 that converts the RF signal into a voltage equivalent that corresponds to the RF level detected. In essence, the modulating signal is reconstructed at voltage levels that represent the peak value transmitted for a digital “high” on the downlink, a digital “low” representing the DOM level, or the CW level on the uplink. The voltage levels for a digital “high” and a CW condition remain virtually the same for the entire 15 dB dynamic range for transmit power due to the corresponding level set on the digital attenuator in the feedback loop. The voltage level for a digital low corresponds to the respective DOM level set for the protocol being transmitted. In normal operation, the signal representing the detected RF level is adjusted for temperature drifts seen by the detector circuit and scaled for input into an analog-to-digital converter (ADC) 99. The output of the ADC 99 is fed into the controlling device 43 on the transceiver 30 that provides control of peak power, CW power, and the DOM, by utilizing closed loop algorithms. The isolator 77 provides isolation of the transmitter from the Tx port and the antenna port. The final RF coupler 78 provides the receive path from the antenna port to the Rx port. Receiver The receiver portion of the transceiver 30, FIG. 4, accepts and processes the backscatter and active responses of the respective transponders. The RF receive chain begins with a band pass filter 82 that includes a pre-attenuator and a post-attenuator followed by a gain block. The filter 82 establishes the pass band for the backscatter receiver and encompasses the pre-selector for the active receiver as well. The sensitivity attenuator 84 and gain block establishes the RF dynamic range of the receiver. The sensitivity attenuator 84 is also adjustable based on the protocol selected, to provide the capability to independently adjust and tune the sensitivities of the respective protocols. The sensitivity attenuator 84 is a 4-bit digital step attenuator that provides 15 dB of dynamic range in 1 dB steps. This attenuator provides the capability to vary the sensitivity level of the interrogator for each protocol. From a calibration standpoint, the sensitivity level of each protocol would be set such that they are approximately the same provided they meet established limits. For instance, if the maximum sensitivity of one protocol is −66 dBm and the maximum sensitivity of another protocol is −63 dBm, both can be calibrated to −62 dBm assuming the limit is −60 dBm. Adjusting for the active and backscatter receive sensitivities aids in the alignment of the capture zone when operating in a multiple protocol environment. The select block 86 provides the capability to select between two different receive paths, a backscatter receive path (along elements 92, 94, 96) and an active receive path (along elements 88, 90), based on the protocol selected. An RF switch is utilized to separate the backscatter receive path and the active receive path. The processor 100 controls the state of the switch through the controlling device 43 on the transceiver 30. The backscatter receive path includes the backscatter receiver 92, baseband processing 94, and zero crossing detectors 96. The backscatter receiver 92 includes a 0 degree power divider, a 90 degree hybrid, isolators, and mixers. The 0 degree power divider allows for an I & Q (In-phase & Quadrature) configuration that has two signals, one that is in-phase and one that is 90 degrees out of phase. To produce the I & Q channels, the LO 48 output is fed through the 90 degree hybrid. The receive and LO paths are then fed through isolators in their respective paths to provide the RF and LO inputs to mixers for direct conversion to base band for processing by the baseband processing 94. The isolators in the 0 degree path are required to isolate the active receiver from the transmitter LO and provide a good voltage standing wave ratio (VSWR) to the hybrid coupler, which results in good phase and amplitude balance. The isolators in the 90-degree path are also required to provide a good VSWR to the hybrid coupler. In the baseband processing 94, filter and amplifier paths are provided for high, medium, and low speed I & Q signals to allow for the differing bandwidth requirements of the respective protocols. Zero-crossing detectors 96 convert the signals into a form required by the controlling device on the transceiver for additional processing. The active receive path includes an active receiver 88 and a threshold detector 90. The active receiver 88 includes a band pass filter, gain block and attenuation, logarithmic amplifier. The band pass filter establishes the pass band and noise bandwidth for the active receiver. The gain block and attenuation combination establishes the dynamic range of the receiver in conjunction with a logarithmic amplifier that converts a received Amplitude Shift Keyed (ASK) transmission to base band. The base band processing, which is part of the active receiver 88, does a peak detect and generates an automatic threshold to provide greater receiver dynamic range and signal level discrimination. A static adjustable range adjust threshold sets the initial threshold level for the threshold detector 90. The threshold level is selected so that the receiver is not affected by noise by setting the initial threshold level for the threshold detector 90 above the receiver's noise floor level. The threshold level also aids in the alignment of the capture zone. In a given application, the capture zone can be reduced from its maximum by increasing this threshold level. Dynamic Adjustments The controlling device 43 on the transceiver 30 provides the necessary functionality and control for factory calibration, initialization, source selection, DOM (closed-loop), RF power (closed-loop), transmitting and receiving, and built-in-test. The preferred embodiment of the controlling device 43 is a Field Programmable Gate Array and the associated support circuitry required to provide the functionality described. The capability to factory calibrate is provided for the synthesizer reference clock, depth of modulation, and RF power. Calibration of the reference clock is provided through a digitally controlled solid-state potentiometer that feeds into the voltage controlled frequency adjust port of the reference oscillator. The oscillator is factory calibrated to a frequency standard that provides the LO for the measuring device. The digitally controlled potentiometer contains on-board non-volatile memory to store the calibrated setting. Depth of modulation calibration is provided for the levels required by the supported protocols. The levels are 20 dB (IT2000), 30 dB (Title 21) and 35 dB (EGO, SEGO, IAG), which are stored in non-volatile memory during factory calibration. The respective levels are retrieved from the controller's 43 memory and loaded into the DOM DAC 70 based upon the protocol that is selected and what the DOM level was set to for the respective protocol during the initialization of the transceiver 30. RF power is calibrated in 1 dB steps over the 15 dB dynamic range for both synthesized sources 33, 45. Each level is stored in non-volatile memory during factory calibration. The respective levels are retrieved from memory and loaded into the downlink and uplink attenuation DACs 72 based upon the protocol that is selected and what the power level was set to for the respective protocol during the initialization of the transceiver 30. The initialization process sets the frequency for the synthesized sources S1, S2, as well as for the downlink attenuation, uplink attenuation, source designation, duty cycle, base band range adjust and sensitivity adjust levels for the respective protocols. A clock, serial data line, and a load signal are provided by the processor 100 to load the synthesizers 33, 45. A serial UART is used to pass attenuation, source designation, range and sensitivity adjust from the processor 100 to the transceiver 30. Source selection and transmit control is provided by the processor 100 via configuration discretes that designate the selected protocol in conjunction with a discrete that indicates whether downlink or uplink is active and a discrete for on/off control. Based upon the active configuration and the parameters set during initialization, the appropriate attenuation levels are set from the calibrated values in memory for the designated source. Acknowledge discretes are provided by the transceiver 30 to facilitate sequencing. The sequence is dictated by the respective protocol and is designed to maximize efficiency. In addition, an acknowledge message can be sent to the tag to activate audio/visual responses as well as put the transponder to sleep for a period of time defined in the acknowledgement message. It is desirable to put a tag to sleep so that it doesn't continue to respond, such as if the vehicle is stuck in a lane, and so that the interrogator can communicate with other tags. The RF power control for the downlink and uplink RF output power is a closed loop system to provide stable power across frequency and temperature, and stable DOM, independent of protocol. In accordance with the preferred embodiment, the closed loop for DOM control includes the controller 43 (which includes the controlling algorithm), DOM controller 60, MOD/CW 56, RF AMP 65, filter 74, coupler 76, attenuator 97, sensor 98, ADC 99, and back to controller 43. The detected coupled output after the power amplifier provides the feedback path to the Field Programmable Gate Array 43. The Field Programmable Gate Array 43 contains closed loop algorithms for controlling both the CW uplink power levels and the peak power levels for the modulated downlink. The closed loop power control algorithm samples the peak power level in the feedback path and compares it to a factory calibrated power level reference. The control voltage (VCTL Attn) is adjusted through the DL/UL DAC & Power Control 72 to zero out the error from the comparison. The DOM control is also a closed loop system to provide stable DOM across frequency and temperature, including for the RF AM DOM. Here, the closed loop for the peak RF power control includes the controller 43 (which includes the controlling algorithm), power controller 72, RF AMP 65, filter 74, coupler 76, attenuator 97, sensor 98, ADC 99, and back to the controller 43. The controller 43 includes a detected coupled output after a power amplifier that provides the feedback path to the Field Programmable Gate Array 43. The Field Programmable Gate Array 43 contains closed loop algorithms for controlling the DOM for the modulated downlink. The closed loop DOM control algorithm samples the minimum power level in the feedback path and compares it to a factory calibrated DOM reference for the respective protocol. The level within the Filter Mod signal that indicates the transmission of a “low” bit, or the DOM (depth of modulation) level, will be adjusted through the DOM DAC & Modulation Control 60 to zero out the error from the comparison. Receive control is provided by the processor 100 via configuration discretes that designate the selected protocol. The microprocessor 102 generates the discretes, which in the preferred embodiment are five signals having a total of 32 unique modes. For instance, a discrete signal could be 00011, which signifies an EGO protocol and its specific parameters for operation. The discretes are sent to the controller 43, and the interrogator 12 configures itself to communicate with the selected tag by setting the appropriate power level, bit rates, backscatter path, and the like. Based upon the active configuration and the parameters set during initialization, the appropriate receiver is activated and the sensitivity adjust level is set from the calibrated values in memory for the respective protocol. The processor 100 contains all of the necessary circuitry to perform or control the various interrogator functions. It contains a microprocessor 102 for running application code which controls manipulating and passing the decoded tag data to the host, communications interfacing, interrupt handling, synchronization, I/O sensing, I/O control and transceiver control. The self test techniques (discussed below) for the system utilizing the loop-back technique and the test tag technique are also controlled by the processor 100 through the configuration control discretes. Dynamic RF Power Adjustment The ability to adjust the level of RF power transmitted serves multiple purposes. Independent of transponder type and external interfering signals, capture zones rely upon the RF power transmitted and the gain of the transmit/receive antenna. The multiple protocols supported by the interrogator translates to the specific requirements of the respective transponders. They can be passive or active, battery or beam powered, with additional variables that are dictated by the physics of the transponder. These variables include transponder receive sensitivity, turn on threshold, antenna cross section and conversion loss. To support these variables, the RF power of the interrogator must be adjustable to levels stored in memory for each protocol such that the appropriate levels are set when the respective protocol is selected. Dynamic Depth of Modulation (DOM) Adjustment The ability to select the DOM level of the transmitted downlink serves major purposes. Independent of transponder type and external interfering signals, the transponders receiver dynamic range relies upon the DOM transmitted during the downlink. The multiple protocols supported by the interrogator translate to the specific requirements of the respective transponders. Their base band processing can be AC or DC coupled, with additional variables that are dictated by the physics of the transponder. To support these variables, the downlink DOM from the interrogator must be selectable to levels stored in memory for each protocol such that the appropriate DOM is set when the respective protocol is selected. Dynamic Modulation Duty Cycle Adjustment The ability to select the duty cycle for the base band downlink modulation provides the flexibility to compensate for finite non-linearity in the modulation path and the capability to optimize the duty cycle to the respective transponder requirements. A synchronous clock provides the capability to lengthen a “high” bit on the modulated signal from the encoder to increase the duty cycle of the signal provided to the DOM DAC & Modulation Control 60. Conversely, lengthening a “low” bit on the modulated signal from the encoder decreases the duty cycle of the signal provided to the DOM DAC & Modulation Control 60. To support this capability, the duty cycle value is retrieved from the memory of the controller 43 that was set during the initialization process for each protocol such that the appropriate duty cycle is set when the respective protocol is selected. The independent adjustment of the duty cycle or pulse width aids in the tuning of the modulated signal to the transponder requirements and in the derivation of transponder sensitivity to variations of duty cycle. For example, the Title 21 specification does not specify duty cycle or the rise and fall times for the reader to transponder communication protocol. Consequently, manufacturers who build transponders that meet the Title 21 specification produce transponders with characteristics that differ with respect to these parameters. Dynamic Frequency Selection Frequency selection is dynamic in the sense that there are separate downlink and uplink sources 33, 45 that are fixed to specific frequencies. In a typical single mode application with multiple interrogators, the downlink (or modulated) frequency is set to the same frequency on all of the interrogators and the uplink (or CW) frequency is set to specific frequencies that are dependent on the respective protocol. Higher data rate protocols require more separation between uplink frequencies but allow for frequency reuse across multiple lanes, i.e., use the same frequency in multiple lanes, without interference. Lower data rate protocols require less separation between uplink frequencies, however, frequency reuse becomes much more of an issue. The interrogator 12 will typically operate on a single downlink frequency, so that only a single downlink synthesizer 45 is needed. However, the uplink signals can be sent on more than one frequency. Since each of the synthesizers 33, 45 operate at a fixed frequency, it would be time consuming to switch the internal frequency for that synthesizer. Accordingly, two synthesizers can be used to send uplink signals. The uplink synthesizer 33 can send an uplink signal on a first frequency, and the downlink/uplink synthesizer 45 can send an uplink signal on a second frequency. It should be recognized, however, that the invention can be implemented using more than one downlink frequency, and more or fewer uplink frequencies. Thus, when a high speed protocol and a low speed protocol are integrated into a single multiple interrogator application, channel limitations arise due to bandwidth limitations imposed by radio regulatory authorities. The system allows for this by the use of the step-lock arrangement and the capability to setup the interrogator to allow the downlink source to be utilized as the uplink source for the low speed protocol while the high speed protocol utilizes the dedicated uplink source. This allows for the high speed and low speed protocols to be channelized independently within the regulatory bandwidth limitations and provides flexibility for the multiple protocol, multiple interrogator application. Self-Test Operation The check tag system of the prior art is not well suited for use with then multiple protocols of the present invention. The multiple check tags used to verify the respective signal paths place additional time constraints and inefficiencies on the system. Instead, turning to FIG. 10, the system includes a self-test operation having the additional capability of synchronizing the self-test cycle within a cluster of interrogators 22. Backscatter operation requires that the interrogator transmit uplink signals as a continuous wave (CW) in order to receive the response from a backscatter transponder. Since the receiver is active during the transmission of the uplink CW, it is possible for the backscatter receivers to detect and process the downlink signal, which is an amplitude modulated (AM) carrier. The serial bit stream originating from the processor 100 via the encoder 104 is looped back to the processor 100 via the decoder 106 as indicated by the dotted lines. The loop starts at the encoder 104, and proceeds to the controller 43 to the DOM DAC & Modulation Control 60, to the MOD/CW 56, to the AMP 65, to the filter 74, to the coupler 76, to the isolation 77, to the coupler 78, to the filter 82, to the sensitivity attenuator 84, to the select 86. At the select 86, the Rx Select signal determines the path that the serial bit stream will take. One state will take it through the backscatter receiver 92 chain while the other state will take it through the active receiver 88 chain. As a result of the loop, the processor 100 is able to verify whether the serial bit stream through the decoder 106 matches the bit stream sent via the encoder 104. If the serial bit stream sent by the encoder 104 matches the bit stream received by the decoder 106, the microprocessor 102 indicates that all of the elements along the test path are operating properly. However, even if the bit stream is off by a single digit, the microprocessor 102 will indicate that the system is not operating properly. Preferably, the test bit stream is between 4 and 16 bits in length, so that the test is fast, though a test could also have a bit stream length of an actual message, i.e., 256 bits. Note that the active receiver 88 is tested as well with this process, if it is active during the transmission of the downlink AM carrier, even though that is not the normal mode of operation and only viable from a test standpoint. The serial bit stream can be a simple pattern and very short in duration compared to the response from even the highest baud rate check tag. This method provides the means to confidence test the downlink source, the RF transmitter chain, the active receiver and the backscatter receivers. The uplink source can be tested in the same manner by simply modulating what would normally be the CW source. However, the loop shown in FIG. 10 does not provide a confidence test of any components after the Tx/Rx coupler 78, i.e., the antenna, or the RF cable. To do so, the system uses the system shown in FIG. 11. The test tag 110 is a switching device connected to a coupling antenna that is mounted near the system antenna. The switching device is controlled by the processor 100 to produce a backscatter response when coupled to the uplink CW transmitted from the system antenna. The serial bit stream for the test tag 110 can be the same simple pattern utilized for the loop-back mode of FIG. 10, or it can be unique. The system of FIG. 11 provides the means to confidence test the uplink source, the RF transmitter chain, the backscatter receivers as well as the antenna and coaxial cable. A full response can be simulated for backscatter tags to facilitate more in-depth testing when it is warranted. A simplified alternative to this method is shown in FIG. 12, where the transmitter is coupled directly to the test tag 110. The self-test system can be used with any transmitter, receiver or transceiver, and need not be used with a step-locking system or an interrogator. In step-lock, the interrogator treats the test sequence as another protocol so that the test occurs in the same time frame. Thus, in the embodiment of FIG. 3(a) for instance, the test sequence would occur after the processing time of Tag Protocol 2 and prior to another Sync Signal. Illustrations FIGS. 13-21 illustrate various embodiments of the system. In each of these embodiments, the system is designed to cover an unlimited number of lanes, though preferably the system is used with up to about eleven lanes of traffic, plus four shoulder lanes. The system accommodates two primary protocols, the first protocol is for a tag sold under the trade name EGO. The first protocol has uplink frequencies that should not be shared since it could result in frequency instability. In addition, there must be at least 500 kHz clear spectrum around each uplink channel. The downlink channels can share the same frequency, or they can be on different frequencies. The downlink spectrum from modulation will interfere with uplink and must be kept out of the uplink receive bandwidth. The second protocol is for an IT2000 tag. The second protocol has tags that wake up in three stages; RF power gets them to stage one, detection of a downlink signal gets them to stage two, and stage three is the tag response to a read request. Uplink frequencies can be shared, and multiple interrogators can use the same channel on the uplink. There must be at least +/−6 MHz of clear spectrum around each uplink channel. Downlink channels can share the same frequency, or they can be on different frequencies. Downlink spectrum from modulation (either the first or second protocols) will interfere with the uplink signal and must be kept out of uplink spectrum. For the interrogators, the downlink and uplink frequencies cannot be changed during operation, but remain fixed at their configuration frequencies. All interrogators are step-locked to each other so that they are synchronous in time. The timing is controlled by the TDM signal and internal CAM files. Step-locking keeps the interrogators from interfering with each other, and eliminates the need for shutting interrogators down during different time slots. Single Tag Protocol In the embodiment of FIGS. 13-18, a system is provided for tags employing a single signaling protocol, which is the IT2000 protocol in this illustration. As best shown in the embodiment of FIG. 15, there are several different commands of different lengths that have to be exchanged between the interrogator 12 and the tag. Since the commands are different lengths, the interrogator 12 adds dead time to the start of the shorter commands to ensure that all downlinks end at the same time. This mode utilizes a frequency plan with the downlink at 918.75 and the uplinks at 903 MHz and 912.25 MHz and 921.5 MHz. The downlink and uplink are locked so that downlink signals do not interfere with uplink signals. However, the interrogators do not have to be command locked. They are able to independently issue commands. That means that one interrogator may issue a read request while a interrogator in another lane is issuing a write request. Only the uplink and downlink are synchronized. Since the downlinks happen at the same time, the uplinks do not occur at the same time as the downlinks, thereby freeing up the entire spectrum for each of the uplink and downlink transmissions. The downlink frequency plan is shown in FIG. 13. In this configuration, all downlinks are operating on the same frequency. FIG. 14 show the uplink frequency plan, where the uplinks use a three frequency reuse plan, namely 921.5 MHz, 912.25 MHz, and 903 MHz. As shown, the range for each of the three different uplink frequencies do not overlap with one another, so that the frequencies are spaced across the lanes to reduce the interference between the interrogators. At the same time, each frequency is present in each of the three lanes, so that the interrogator for each lane can receive information on any of the uplink frequencies. The oval patterns are created by positioning an interrogator antenna 18 at the top of the oval. In operation, upon power up or after a reset has occurred, the interrogator is initialized with the parameters required for the respective application, such as the downlink and uplink frequencies. Protocol specific parameters are also set during initialization, including downlink and uplink power level, DOM level, sensitivity attenuation, range adjust, as well as source, receiver and transmitter assignments for the specific application protocol. Those parameters correspond to the five bit configuration assigned in the processor 100 to the protocol. Thus, for IT2000, a configuration of 00010 from the processor 100 signals the transceiver 30 to retrieve the IT2000 specific parameters from the controller 43 memory for an impending communication sequence. The transceiver acknowledges the processor 100, and indicates that it has received and set the appropriate parameters for the specific configuration. If it is a single protocol application, and the configuration does not change, occurs once since the transceiver 30 will then be set to the appropriate configuration from that time forward. The processor 30 turns on the transceiver 30 transmitter chain and an IT2000 command is encoded and transmitted on the downlink source at a specific power and DOM level initialized for the IT2000 tags. The modulation signal travels through the high-speed transmit filter path set during initialization. Shortly after the downlink transmission is complete, the control signal changes state to turn the downlink source off. This also turns the uplink CW source on at a specific power level and enables the respective receive parameters that were set during initialization. If an IT2000 transponder response is received and decoded through the high-speed backscatter path, it is processed at the end of the uplink CW transmission and the sequence repeats. All timing is tightly controlled to accommodate the step-lock techniques. If step-lock is enabled, the sequences are keyed from the reception of the synchronization signal. Turning to FIG. 15, the timing of the various uplinks and downlinks is shown. The timing gives an overall time per slot of at least about 3.5 ms, though the timing could be reduced to about just over 2 ms (the time it takes to complete the longest transaction, if no processing time was required. At 3.5 ms, the entire transaction takes a minimum of about 21 ms. In 3.5 ms a vehicle travels 0.51 feet (100 mph), and in 21 ms a vehicle travels 3.08 feet. Accordingly, the tag has the opportunity to cycle through the protocol several times prior to vehicle traveling a distance beyond the range required to uplink and downlink signals. For a 10 foot read zone, the tag could complete approximately 3.3 entire transactions. As shown in FIG. 15, various downlink and uplink communication protocols are utilized by the interrogator. The commands are defined in the following Table 1. Thus, for instance, pursuant to the first command, Read Page 7, the interrogator sends a read request to the tag on the downlink, and the tag sends a read response on the uplink. TABLE 1 Protocol Commands Command Downlink Uplink Read Page 7 Read Request Read Response Read Page 9 Read Request with ID Read Response Random # Request Random # Request Random # Response Write Page 9 Write Request with ID Write Response Write Page 10 Write Request with ID Write Response Gen Ack General Acknowledgement No Response In the example of FIG. 15, a different interrogator 12 transmits each of the commands. Accordingly, the duration of the uplink, downlink, uplink dead time, downlink dead time, and interrogator processing time differs for each of the various commands. For instance, the Write Page 9 and Write Page 10 commands have long downlink periods since information is being written. However, the signals are step-locked, so that all of the downlinks end at the same time and the uplinks start at the same time. Thus, there is no interference between the uplink and downlink transmissions. Two Signaling Protocols In the embodiment of FIGS. 16-18, a system is provided for tags employing two signaling protocols, which are the IT2000 and EGO protocols in this illustration. FIGS. 16-17 show the spectrum requirements for the frequency plan, with FIG. 16 showing the downlink plan and FIG. 17 showing the uplink plan. The plan requires that the downlink and uplink be synchronized for all interrogators. That means that during a certain time period all interrogators are transmitting their downlink signals. During the next time period the interrogators are transmitting their uplink signals. During these time periods the interrogators may be supporting either of the two protocols. It is not required for the interrogators to be synchronized for the protocols, only that the downlink or uplink signals be synchronized. During the downlink cycle, all of the interrogators transmit at 918.75 MHz. During the uplink cycle, the odd IT2000 interrogators transmit at 921.5 MHz, and the even interrogators transmit at 903 MHz. The EGO uplinks are spaced between 910 MHz and 915.5 MHz. The interrogators have to be either IT2000 or EGO interrogators. The means that if lane coverage requires 7 coverage areas, this implementation would require 14 separate interrogators. Or if the interrogators are frequency agile, then the interrogator could switch between the required IT2000 uplink frequency and the required EGO uplink frequency depending on the protocol being transmitted at that time. Adding additional interrogators can cover additional lanes. The number of EGO uplink channels that can be supported between 910 MHz and 915.5 MHz limits the number of lanes. If the spacing between interrogators can be reduced to 500 kHz, the number of EGO interrogators supported would be 12. If additional EGO interrogators are needed then all the IT2000 uplinks could be moved to 903 MHz and room for an additional 12 EGO interrogators would be available between 915.5 MHz and 921.5 MHz. This configuration would support 24 EGO interrogators. In operation, upon power up or after a reset has occurred, the interrogator is initialized with the parameters required for the respective application, such as the downlink and uplink frequencies. Protocol specific parameters are also set during initialization, including downlink and uplink power level, DOM level, sensitivity attenuation, range adjust, as well as source, receiver and transmitter assignments for the specific application protocols. Those parameters correspond to the five bit configuration assigned to the respective protocol. A configuration of 00010 from the processor 100 signals the transceiver 30 to retrieve the IT2000 parameters from memory for an impending communication sequence. The transceiver acknowledges the processor 100, indicating that it has received and set the appropriate parameters for the IT2000 protocol. The processor 30 then turns on the transceiver 30 transmitter chain and an IT2000 command is encoded and transmitted on the downlink source at a specific power and DOM level initialized for the IT2000 protocol. The modulation signal travels through the high-speed transmit filter path set during initialization. Shortly after the downlink transmission is complete, the control signal changes states to turn the downlink source off. That also turns the uplink CW source on at a specific power level and enables the respective receive parameters that were initialized for the IT2000 protocol. If an IT2000 transponder response is received and decoded through the high-speed backscatter path, it is processed at the end of the uplink CW transmission. A configuration of 00011 from the processor 100 then signals the transceiver 30 to retrieve the EGO parameters from memory for an impending communication sequence. The transceiver acknowledges the processor 100, thereby indicating it has received and set the appropriate parameters for the EGO protocol. The processor 30 turns on the transceiver 30 transmitter chain and an EGO command is encoded and transmitted on the downlink source at a specific power and DOM level initialized for the EGO protocol. The modulation signal travels through the low-speed transmit filter path set during initialization. Shortly after the downlink transmission is complete, the control signal will change states to turn the downlink source off. That also turns the uplink CW source on at a specific power level and enables the respective receive parameters that were initialized for the EGO protocol. If an EGO transponder response is received and decoded through the low-speed backscatter path, it is processed at the end of the uplink CW transmission and the entire sequence will repeat. All timing is tightly controlled to accommodate the step-lock techniques. If step-lock is enabled, as in FIG. 3(a), the sequences are keyed from the reception of the synchronization signal. The IT2000 protocol is Tag Protocol 1 and the EGO protocol is Tag Protocol 2. FIG. 16 shows how the downlink frequency is used to cover a system that has three lanes with coverage for the shoulders of each of the outside lanes, and FIG. 17 shows the layout for the uplink frequencies. In the figures, the circles represent the coverage achieved over an area of the road surface. The numbers in the circles represent the individual interrogators, with the number on the left for the IT2000 interrogator and the number on the right for the EGO interrogator. The numbers assigned to each half-circle represent the frequency being used by that particular interrogator and matches up with a frequency on the left. The IT2000 interrogators alternate between frequencies at 903 MHz and 921.5 MHz. The IT2000 protocol allows the frequencies to be shared without the interrogators significantly interfering with each other. The EGO interrogators use the frequencies between 909.75 MHz and 915.75 MHz. Since each EGO interrogator requires a unique frequency for its uplink, the EGO frequencies are not shared. FIG. 18 displays the timing required for the commands used by EGO and IT2000 tags. The first line is the EGO read command, which is a group select for the downlink and a work data (tag ID) on the uplink. This is the only EGO command required for this illustration. Upon receiving this command, the EGO tag reports back its ID. The rest of the commands are the IT2000 commands listed in Table 1 above, which are completed in the sequence shown. The critical timing location is the transition between the uplink and downlink. That transition needs to occur at nearly the same time for all of the interrogators. If an interrogator stays in a downlink mode for too long, it could interfere with the uplink signals. The dead time for both the uplink and downlink is the time that no commands are being sent or received by the interrogator. The interrogators generally use the dead time to align their downlink and uplink signals. The processing time is the time required by the interrogator to process commands received by the tag. The interrogator alternates between an EGO Read command and an IT2000 Read Page 7 command until it receives a tag response. An EGO tag response is processed during the uplink time and then is followed by an IT2000 Read Page 7 Command. The rest of the IT2000 commands follow an IT2000 tag response to the Read Page 7 Command. By setting up the system the present way, an interrogator at one lane that is processing an IT2000 tag does not force the rest of the interrogators in the other lanes to wait until that tag is finished. The rest of the interrogators can continue to alternate between the IT2000 and EGO reads. The system dramatically increases the time required to process an IT2000 command. The current IT2000 transaction takes around 14 ms plus some additional transaction time. The minimum amount of time required for this process would be about 40 ms. If the interrogator misses any commands and the missed commands have to be repeated, the time would increase by about 7 ms per repeated command. At 100 mph, a vehicle travels about 6 feet in 40 ms, which is a significant portion of the capture zone. FIGS. 19-21 is another illustration of the system used with multiple backscatter protocols, namely EGO and IT2000. In the present illustration, the interrogators incorporate the capability of using either source 33, 45 as an LO in the receiver. This allows interrogators to use different frequencies for the EGO and IT2000 uplinks. Only one source needs to be modulated since the EGO and IT2000 downlinks can be on the same frequency. All of the interrogators are step-locked in time so that they are all performing the same operation at the same time. This ensures that no interrogators are transmitting while another interrogator is trying to receiving. In addition, a frame consists of an IT2000 command set and an EGO command set. During the IT2000 command set the entire IT2000 command sequence is sent. Therefore, during one frame an IT2000 tag can be read, written to, and generally acknowledged off before the command set returns to the EGO commands. The frame is approximately 14 ms in duration covering both the EGO and IT2000 command set. In order to reduce the time required to complete the IT2000 transaction, the IT2000 transaction has been reduced to a single read, single write and three general acknowledgements. FIG. 19 shows the spectrum requirements for the frequency plan. The blocks represent the frequency location and bandwidth required for each signal. The IT2000 signals are wider because of IT2000's faster data rate requiring more spectrum. The figure shows that the EGO signals and the IT2000 downlink signal share the same center frequency. These signals use one of the sources in the interrogator while the other source is used by the IT2000 uplink signals. The numbers in the blocks represent the different interrogators used to cover the lanes. The IT2000 downlink and EGO uplink and downlink frequencies are spaced across the 909.75 to 921.75 MHz band. The spacing requirement is determined by the selectivity of the EGO receive filters. The narrower the EGO uplink filters, the tighter the frequencies can be spaced and the greater the number of lanes that can be supported. If the spacing can be reduced to 500 kHz between channels, this setup supports 13 interrogators. An additional two EGO interrogators could be added at 903 and 921.5, by sharing the uplink signals used by the IT2000 channels. This would give a total of 15 interrogators, or the ability to support 6 lanes and 4 shoulders. FIG. 19 also shows a frequency plan for a 3-lane system for the IT2000 downlink and the EGO interrogators. For this implementation, each interrogator is on a different frequency to eliminate the frequency reuse issue associated with the EGO uplink. Lane discrimination is accomplished by setting the correct power levels from the interrogators. To get more lane coverage the power is increased to reduce lane coverage the power is decreased. As shown in FIG. 20, the IT2000 uplink signals are at 903, 912.25, and 921.5. The minimum spacing for IT2000 uplink is determined by the selectivity of the IT2000 receive filters. These filters need about 6MHz of spacing between channels. However, unlike the EGO uplink channels, the IT2000 uplink frequencies can be reused so that several interrogators can use the same channel. FIG. 20 also shows the frequency plan for a 3-lane system for the IT2000 uplink interrogators. For this implementation, the IT2000 uplinks share three center frequencies: 903, 912.25 and 921.5. Since the IT2000 uplink channels can reuse the same frequency, those frequencies are shared over several interrogators. The figure shows one method of setting up the lanes to reduce the co-channel interference by separating interrogators that use the same frequency as far apart physically as can be accomplished. FIG. 21 shows the timing associated with step-locking all of the interrogators together. For that system, all interrogators are locked together on the same timing. Locking the signals together ensures that no interrogator is performing downlink modulation while another interrogator is attempting to receive an uplink signal. If that were to happen, the downlink modulation could interfere with the uplink signal and block its reception. The timing plan assumes that the IT2000 commands are reduced to a single read, a single write, and three general acknowledgements (Gen Ack). The system transmits the read request until it receives a read response and then the rest of the read, write, and gen ack commands are completed. In this method, the system completes the entire read, write, and gen ack command set each cycle. The cycle time for these commands is around 14 ms. At 100 mph a vehicle travels about 2 feet. If the read area is 10 feet deep then the system should get between 4 and 5 reads depending on when in the cycle the tag enters the capture zone. The foregoing description and drawings should be considered as illustrative only of the principles of the invention. The invention may be configured in a variety of ways and is not intended to be limited by the preferred embodiment. Numerous applications of the invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to interrogatory systems. More particularly, the present invention relates to an interrogatory system having closely-spaced interrogators that simultaneously process different tag protocols or commands. 2. Background of the Related Art As discussed in U.S. Pat. No. 5,030,807 to Landt, RFID (radio frequency identification) systems use frequency separation and time domain multiplexing in combination to allow multiple interrogators to operate closely together within the bandwidth limitations imposed by radio regulatory authorities. In transportation and other applications, there is a compelling need for interrogators to operate in close proximity. In the example of a toll collection system, many lanes of traffic are operated side by side, and it becomes necessary to simultaneously read tags that are present in each lane. This introduces new challenges, particularly when a system is designed to communicate with tags of differing protocols, requiring performance sacrifices. Backscatter RFID systems, because they are frequency agile, can use frequency separation to allow simultaneous operation of closely spaced interrogators. However, the ability to operate with acceptable performance is limited by the ability of the interrogator to reject adjacent channel interference, and in the case where frequencies are re-used, co-channel interference. In addition, the interference impact of operating multiple interrogators in close proximity to one another is complicated by second and third order inter-modulation effects. Because the downlinks (interrogator to tag) are modulated signals and the uplink signals (tag to interrogator) are continuous wave (CW) carriers at the interrogator, the interference on an uplink by a downlink is more severe in most cases than either downlink on downlink interference or uplink on uplink interference. When downlink on uplink interference debilitates performance beyond an acceptable level, the system could be set up for time division multiplexing among the interrogators. Interrogators would then share air time (take turns) according to a logic scheme to minimize or eliminate the impact of the interference between interrogators. That, however, results in lower speed performance since a given transaction requires more total time to complete. When a large number of lanes are involved, the speed performance loss can be severe and unacceptable. Active RFID systems typically cannot use frequency separation due to the fact that cost-effective active transmitters operate on a fixed frequency. These systems have therefore followed an approach of operating in a pure time division mode to prevent interference among closely located interrogators. Downlink on downlink interference typically occurs when a tag receives the signals from two interrogators. If the interrogators are closely spaced, the RF level of the two transmitted bit streams may be comparable. If significant RF from the adjacent interrogator is received during bit period when none should be received, the tag may incorrectly decode the message. From a self-test perspective, RFID systems typically utilize what is commonly known as a “check tag” to provide a level of confidence regarding the health of the RFID system. The check tag can be an externally powered device that responds only to a specific command or responds only to its programmed identification number. It can be built into the system antenna or it can be mounted on or near the system antenna. It can also be housed within the interrogator and coupled to the system antenna via a check tag antenna mounted near the system antenna. Though the check tag can take a variety of forms, one commonality is that the check tag must be activated in some manner so that the response can be read by the interrogator and remain inactive during normal operation. When a check tag is activated, it typically provides a response that can be read by the interrogating device. The check tag response is generally the same as what would be received by the interrogator during normal operation as a tag passes through the system in that particular application. If a backscatter RFID system initiates a check tag and a response is received, it verifies the RFID system is operational to the point that RF has been transmitted and the check tag backscatter response received and decoded. Encoded modulation of the RF is only verified if the check tag requires a modulated signal to trigger its response. The time that it takes to complete the cycle depends upon the type of tag utilized and can range from a few to several milliseconds, and the cycle is repeated periodically. | <SOH> SUMMARY OF THE INVENTION <EOH>It is therefore one object of the present invention to provide an interrogating system that is able to simultaneously operate a plurality of closely-spaced interrogators. It is another object of the invention to provide an interrogating system that synchronizes a plurality of interrogators. It is another object of the invention to provide a system that simultaneously processes different protocols used to communicate with tags. It is another object of the invention to provide a system that simultaneously processes different backscatter protocols. It is yet another object of the invention to provide a system that simultaneously processes different active and backscatter protocols. It is yet another object of the invention to provide an interrogating system that avoids interference on an uplink by a downlink, as well as downlink on downlink interference, and uplink on uplink interference. It is yet another object of the invention to provide a self-test operation that can verify operation of the interrogator and that does not have the time constraints of the check tag. It is another object of the invention to provide an interrogation system in which uplink signals are received, and downlink signals are sent, over a single antenna. In accordance with these and other objects of the invention, a multi-protocol RFID interrogating system is provided that employs a synchronization technique (step-lock) for a backscatter RFID system that allows simultaneous operation of closely spaced interrogators. The interrogator can read both active and backscatter tags more efficiently when combined with time division multiplexing. The multi-protocol RFID interrogating system can communicate with backscatter transponders having different output protocols and with active transponders, including: Title 21 compliant RFID backscatter transponders; IT2000 RFID backscatter transponders that provide an extended mode capability beyond Title 21; EGO™ RFID backscatter transponders, SEGO™ RFID backscatter transponders; ATA, ISO, ANSI AAR compliant RFID backscatter transponders; and IAG compliant active technology transponders. The system implements a step-lock operation, whereby adjacent interrogators are synchronized to ensure that all downlinks operate within the same time frame and all uplinks operate within the same time frame. The step-lock operation allows for improved performance with higher capacity of the RFID system. Active and backscatter technologies are implemented so that a single interrogator can read tags of both technology types with minimal interference and resulting good performance. The step-lock operation eliminates downlink on uplink interference. Because downlink on uplink interference is the most severe form of interrogator-to-interrogator interference, that has the net impact of reducing the re-use distance of a given frequency channel significantly. The step-lock technique can be extended to reduce or eliminate downlink on downlink interference for fixed (repeating) downlink messages. This can be achieved by having the interrogators transmit each bit in the downlink message at precisely the same time. Depending on radio regulations and the number of resulting available frequency channels with a given backscatter system, that can allow re-use distances sufficiently close that an unlimited number of toll lanes can be operated without any need to time share among interrogators, drastically improving performance and increasing capacity of the overall RFID system. Step-locking of the interrogators allows the interrogators to operate in a multi-protocol mode, whereby the same interrogator can read both active and backscatter tags in a more efficient way. This is accomplished by combining a time division strategy for active transponders and the step-locked frequency separation strategy for backscatter tags into one unified protocol. | 20040709 | 20090616 | 20060112 | 97669.0 | H04Q522 | 1 | NGUYEN, NAM V | MULTI-PROTOCOL OR MULTI-COMMAND RFID SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | H04Q | 2,004 |
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10,887,342 | ACCEPTED | Removable garment protective assembly | A garment has a pants leg with a front layer stitched along an outer peripheral seam to the pants leg to form a pocket with an interior cavity. The front layer has a central opening spaced from the outer peripheral seam and defined by an inner periphery. A protective insert, which may be formed of foam, and which is larger than the central opening is removably positionable within the pocket. A stiff cap formed of a material such as SANTOPRENE® thermoplastic elastomer, is stitched to the insert. The cap has a flange which projects outwardly from a central region around a line of attachment. The central region is no larger than the pocket central opening. The insert is removably receivable within the pocket such that the inner periphery of the front layer is engaged between the stiff cap flange and the insert. | 1. A garment protective assembly comprising: a garment having a front layer positionable to overlie a portion of a human body which to be protected; portions of the front layer which define a central opening defined by an inner periphery; a protective insert being larger than the central opening; and a stiff cap fixed to the protective insert, the cap having a central region surrounded by a line of attachment where the cap is fixed to the protective insert, wherein a flange projects outwardly from the central region, the flange projecting frontwardly of the insert, the flange having portions which engage the front layer, such that the cap extends frontwardly of the front layer, and the protective insert extends rearwardly of the front layer, the insert being thus removably connected to the garment. 2. The garment protective assembly of claim 1 wherein the garment has a flexible substrate which is positionable to overlie the joint, and wherein the front layer extends frontwardly of the garment substrate to define a pocket positioned rearwardly of the central opening to receive the insert therein. 3. The garment protective assembly of claim 2 wherein the the front layer is attached to the garment substrate along an outer periphery, and where portions of the periphery open outwardly to permit the insert with attached cap to be inserted into the pocket, prior to the cap being passed through the central opening. 4. The garment protective assembly of claim 3 further comprising a pocket flap which selectably closes the portions of the periphery which open outwardly. 5. The garment protective assembly of claim 1 further comprising a hem which extends around the-front layer central opening, and wherein a drawstring extends within the hem, to permit the dimensions of the central opening to be restricted by adjusting the drawstring. 6. The garment protective assembly of claim 1 further comprising;. a first part of a two-part fastener mounted to the front layer; and a second part of the two-part fastener mounted to the insert to engage with the first part rearwardly of the front layer. 7. The garment protective assembly of claim 6 wherein the first-part of the two-part fastener comprises one half of a hook-and-loop fastener, and wherein the second part of the two-part fastener comprises another half of a hook-and-loop fastener. 8. The garment protective assembly of claim 6 wherein the two-part fastener comprises the two parts of a snap fastener. 9. The garment protective assembly of claim 1 wherein portions of the cap define a groove which encircles the cap central region, and wherein a thread extends within the groove, the thread stitching the cap to the protective insert. 10. The garment protective assembly of claim 1 wherein the flange has a peripheral ridge which projects from the flange towards the front layer. 11. The garment protective assembly of claim 1 further comprising a second cap fixed to the protective insert, and wherein the front layer has a second central opening which receives the second cap. 12. The garment protective assembly of claim 1 wherein the protective insert has a front wall having a snap fit projection, and the cap has a rearwardly extending snap fit protrusion which engages the the snap fit projection with portions of the front layer secured therebetween. 13. The garment protective assembly of claim 1 further comprising an adjustable band mounted to the garment, the band comprising: a first strap fastened to the garment substrate; a second strap fastened to the garment substrate; and a two-part hook and loop fastener, having a first part on the first strap, and a second part on the second strap, the first strap being thereby releasably engagable with the second strap to adjust the dimensions of the garment rearward of the insert. 14. The garment protective assembly of claim 11 wherein the garment has an interior, and wherein both the first strap and the second strap are positioned on the interior of the garment. 15. A garment protective assembly comprising: a garment having a flexible substrate positionable to overlie a portion of a human body to be protected; a front layer fixed to the garment substrate, wherein a pocket is defined between the front layer and the garment substrate, the front layer being fixed to the garment substrate by an outer peripheral seam, wherein the pocket defines an interior cavity which is exterior to the garment substrate; portions of the front layer which define a central opening, the central opening being spaced from the outer peripheral seam and providing access to the pocket interior cavity, the central opening being defined by an inner periphery; a protective insert which is removably positionable within the pocket, the insert being larger than the central opening; and a stiff cap fixed to the protective insert, the cap having a central region surrounded by a line of attachment, and wherein a flange projects outwardly from the central region around the line of attachment, the flange projecting frontwardly of the insert, and wherein the central region is no larger than the pocket central opening, and wherein the protective insert is removably receivable within the pocket such that the inner periphery of the front layer is engaged between the stiff cap flange and the insert. 16. The garment protective assembly of claim 15 wherein portions of the outer peripheral seam are interrupted to open outwardly to permit the insertion into the pocket of the insert with attached cap, and to permit the cap to be passed through the central opening. 17. The garment protective assembly of claim 16 further comprising a pocket flap which selectably closes the interrupted portions of the outer peripheral seam which open outwardly. 18. The garment protective assembly of claim 14 further comprising a hem which extends around the front layer central opening, and wherein a drawstring extends within the hem, to permit the dimensions of the central opening to be restricted by adjusting the drawstring. 19. The garment protective pad assembly of claim 15 further comprising; a first part of a two-part fastener mounted to the front layer; and a second part of the two-part fastener mounted to the insert to engage with the first part within the pocket. 20. The garment protective pad assembly of claim 19 wherein the first part of the two-part fastener comprises one half of a hook-and-loop fastener, and wherein the second part of the two-part fastener comprises another half of a hook-and-loop fastener. 21. The garment protective assembly of claim 15 wherein portions of the cap define a groove which encircles the cap central region, the groove coinciding with the line of attachment, and wherein a thread extends within the groove, the thread stitching the cap to the protective insert. 22. The garment protective assembly of claim 15 wherein the flange has a peripheral ridge which projects from the flange towards the front layer. 23. The garment protective assembly of claim 15 further comprising an adjustable band mounted to the garment, the band comprising: a first strap fastened to the garment substrate; a second strap fastened to the garment substrate; and a two-part hook and loop fastener, having a first part on the first strap, and a second part on the second strap, the first strap being thereby releasably engagable with the second strap to adjust the dimensions of the garment rearward of the insert. 24. The garment protective assembly of claim 23 wherein the garment has an interior, and wherein both the first strap and the second strap are positioned on the interior of the garment. 25. The garment protective assembly of claim 15 further comprising a second cap fixed to the protective insert, and wherein the front layer has a second central opening which receives the second cap. 26. A garment protective assembly comprising: a garment having a front layer positionable to overlie a portion of a human body which it is desired to protect; portions of the front layer which define a central opening defined by an inner periphery; a protective insert being larger than the central opening; and a stiff cap fixed to the protective insert, the cap projecting from the central opening and extending frontwardly of the front layer, and the protective insert extends rearwardly of the front layer, wherein the insert is releaseably engaged with the front layer, the insert being thus removably connected to the garment. 27. The garment protective assembly of claim 26 further comprising: a first part of a two-part fastener fixed to the protective insert and facing frontwardly and encircling the stiff cap; and a second part of the two-part fastener fixed to the front layer and facing rearwardly to engage the first part of the two-part fastener. 28. The garment protective assembly of claim 27 wherein the two-part fastener is a hook and loop fastener. 29. The garment protective assembly of claim 26 wherein the protective insert has a front wall having a snap fit projection, and the cap has a rearwardly extending snap fit protrusion which engages the the snap fit projection with portions of the front layer secured therebetween. | STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of contract No. DAAD 16-01-C-0061 awarded by the US Army Robert Morris Acquisition Natick Contracting Division of the United States CROSS REFERENCES TO RELATED APPLICATIONS Not applicable. BACKGROUND OF THE INVENTION The present invention relates to protective clothing in general, and more particularly to garments which incorporate pads for protection of the wearer's joints such as elbows and knees. There are many activities which require practitioners to take on cramped or reduced postures, such as crouching, crawling or lying prone, either momentarily or for extended periods. Moreover, it is sometimes necessary to assume these positions rapidly or unexpectedly. Kneeling and crawling, or collapsing to the knees, can be particularly injurious to the knees, either as a result of abrasion in the form of scraping, cutting, or puncturing, or as a result of impact or trauma. Flooring installers, carpenters, plumbers, and electricians are examples of tradesman who must occasionally or regularly spend time on their knees. Police officers, customs officials, and soldiers also are frequently required to kneel, crouch, or crawl, and often instantaneously in response to a sudden threat. Certain sporting and leisure activities can also lead to joint injuries if precautions are not taken. Conventional knee and elbow pads provide some measure of protection against impact by supplying a cushion over the joint. In addition, the force of a point impact can be distributed over a greater surface area by stiff shells which are fastened to the cushion. The stiff shells also provide protection against minor cuts and abrasions, while at the same time protecting the cushion itself from degradation. Elbow and knee pads are commonly of one of two types. Independent pads are mounted directly to the wearer's limbs by straps or belts. These devices offer the advantage of being securely attached in the vicinity of the joint to be protected, and being readily replaced for cleaning or repair. This type of pad is often employed where the wearer is otherwise lightly clad, such as in certain sporting activities. However, the tight elastic straps can be uncomfortable or can limit mobility. Moreover, the close-fitting pads can be especially hot during extended wear. In addition, the independent pads can be difficult to combine with other necessary garments, such as coveralls, fatigues, or jumpsuits, as the padding may, when used in combination with such clothing, restrict movement and ventilation and interfere with the garment. Furthermore, the hard shell of an independent pad, if worn interior to the garment, can result in the shredding or abrasion of the garment itself, which is caught between the hard shell of the pad and the hard exterior objects. If worn exterior to the garment, the pad can be excessively restrictive of the movement of the garment, and impair the mobility of the wearer. Garment-mounted pads are often more comfortable, and the hard shell of the pad worn on the exterior of the garment fabric serves to extend the life of the garment itself. Garment and pad wear may, however, progress at different rates, and it may be desirable to replace one and not the other. Or, it may be necessary to remove any foam padding in order to adequately wash the garment, or to safely subject the garment to drying heat. Some garments have pockets into which the foam pad is inserted, but if the hard shell is also inserted into this type of pocket, it would no longer provide protection for the garment fabric. What is needed is a replaceable garment mounted pad assembly, which includes both cushioning foam and an outwardly facing stiff shell, and which can be readily removed and reinstalled or replaced. SUMMARY OF THE INVENTION The protective pad assembly of this invention has a stiff plastic cap which is attached to a resilient cushioning insert or pad in such a way that a stiff flange projects outwardly from the cap to define a gap between the flange and the cushioning pad which can receive the fabric of an outer layer of a centrally opening pocket formed on the garment. The outer layer is a sheet of material with a central opening, which is stitched to the fabric of a garment pants leg or arm on all four sides. The pocket cavity so defined may open only frontwardly through the central opening. The pad is flexible and larger than the central opening in the outer layer covering the knee or elbow. The pad can be inserted by flexing and compressing it into the circumferential hole so that the circumferential lip defining the hole in the outer layer is sandwiched between the shell and the pad. The cap and the pad are thus held in position, but both parts are readily removed for cleaning, repair, or replacement. An adjustable resilient strap may be attached to the interior of the garment to permit adjustment of the fit of the pad assembly. Alternatively, the central opening may be formed in a front layer without any backing garment substrate, so that the pad may be engaged directly by the wearer. It is an object of the present invention to provide a protective pad assembly for a garment which protects the garment and the wearer from abrasion and impact. It is another object of the present invention to provide a protective pad assembly which is readily removed and replaced, and which is connected to a garment, without being directly connected to the wearer. Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a protective pad insert of the protective assembly of this invention. FIG. 2 is a perspective view of a garment having a pocket adapted to receive the protective pad insert of FIG. 1. FIG. 3 is a perspective view of the garment of FIG. 2 with the protective pad insert of FIG. 1 removably received therein. FIG. 4 is a cross-sectional view of the assembly of FIG. 3 taken along section line 4-4. FIG. 5 is a side elevational view, partially broken away in section of an alternative embodiment protective assembly of this invention, in which the pad may engage directly against a wearer's knee. FIG. 6 is a perspective view of another alternative embodiment protective assembly of this invention, with the protective insert removed from the garment, and showing a draw string assembly prior to being constricted. FIG. 7 is a perspective view of yet another alternative embodiment protective assembly of this invention, in which the protective insert pocket has an opening along one edge which is closed with a flap. FIG. 8 is an exploded fragmentary perspective view of an alternative embodiment protective assembly of this invention having a knee and shin protective cap attached to a single cushioning insert and receivable within a front layer of material having two front openings. FIG. 9 is an exploded perspective view of an alternative embodiment protective assembly of this invention having a stiff cap which is separable from the insert in a snap fit relationship. FIG. 10 is a fragmentary perspective view of yet another alternative embodiment protective assembly of this invention, in which the insert is attached to the front layer of the pocket by a hook and loop fastener. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to FIGS. 1-10, wherein like numbers refer to similar parts, a protective pad assembly 20 is shown in FIGS. 1-4. The protective pad assembly 20 is comprised of a protective element 22 shown in FIG. 1, and a pocket 24 formed on a pants leg 26 of a garment 28, for example a soldier's fatigues. The pocket 24 is accessible through a central opening 36, and in a first embodiment is not open at the top or sides as in a common pocket. As shown in FIG. 2, the pocket 24 is defined between a fabric front layer 30 and a frontwardly facing fabric substrate 32 of the garment 28. The protective pad assembly illustrated is a knee pad assembly, but a similar arrangement for an elbow or other body area pad may be provided. The front layer 30 is connected to the garment substrate 32 at an outer peripheral seam 34, formed, for example, by stitching. A central opening 36 is defined in the front layer 30 which has an inner periphery 38 which may be finished by a sewn seam. It will be noted that the front layer 30 does not lie flat against the garment substrate 32, but is spaced from the substrate to define a pocket interior cavity 40 which is dimensioned to snugly receive portions of the protective element 22. The pocket 24 permits the insertion of portions of the protective element 22 through the frontwardly facing central opening 36. The protective element 22, as shown in FIGS. 1 and 4, has a stiff cap 42 which is connected to a protective cushioning insert 44. The insert, as shown in FIG. 1, is a tapered rectangle of cushioning material. The insert 44 is generally resilient and may be dual density polyethylene/EVA foam and may be about ¼ to ¾ inches thick. The stiff cap 42 may be fabricated of a thermoplastic elastomer such as SANTOPRENE® plastic material manufactured by Advanced Elastomer Systems of Exxon Mobil Corporation. This plastic material, although stiffer than most rubbers, nonetheless is generally softer than a plastic such as polyethylene. The stiff cap 42 may be a molded material, which preferably has a slightly convex shape to give strength and stiffness and selected to protect the joint for which it is intended. It will be noted that the stiff cap 42 has some resilience, permitting a small amount of bending of portions of the cap. As best shown in FIG. 4, the cap 42 has formed therein a shallow groove 46 which encircles the cap center 48. A flange 50, about one-half inch wide, extends outwardly from the groove 46 and from the cap center 48. The back side of the flange 50 is preferably formed with a narrow peripheral ridge 52 which is approximately a semicylindrical bead which faces toward the pocket front layer 30. The groove 46 permits a thread 54 to be stitched through the cap and the cushioning insert 44, thereby connecting the cap 42 to the protective cushioning insert 44 without the thread protruding outwardly from the cap. Other effective connection mechanisms between the cap and the insert 44 may be employed, so long as the flange 50 remains protruding from the cap 42. The flange 50 is thus not fixed to the insert 44 outwardly of the groove 46, with the result that a gap 56 is defined between the cap and the insert 44. The size of the cap center 48 is selected to be slightly smaller than the size of the inner periphery 38 of the pocket central opening 36. As shown in FIG. 3, the insert 44 may be inserted into the interior cavity 40 of the pocket 24 such that the inner periphery 38 of the pocket front layer 30 is received within the gap 56 between the cap 42 flange 50 and the insert 44. The cap 42 engages the material of the front layer 30, and thereby holds the protective element 22 in place. The insert 44 may be substantially larger than the cap 42. For example, a cap 42 which is about four inches wide and five inches high, may be connected to an insert which is about five inches wide and ten inches high. The cap 42 may be positioned closer to the top of the insert 44 than to the bottom. To attach the protective element 22 to the garment 28, the protective element is held so that the downwardly tapered insert 44 is compressed to pass through the central opening 36. The insert 44 is advanced until the fabric of the pocket front layer 30 is received in the gap 56 beneath the beadlike ridge 52 on the rear of the cap flange 50. The insert 44, which is readily compressed and distorted, is then worked around the perimeter of the cap 42 so the edge of the pocket front layer goes under the cap flange. Any tendency for the upper portion of the insert 44 to move downward in the pocket as the wearer's joint is flexed may be resisted by a two-part fastener extending between the insert 44 and the pocket front layer 30. The two-part fastener may be a hook-and-loop fastener 58 such as VELCRO® fastener from Velcro Industries B.V., or another conventional fastener such as a snap fastener having a socket as one part, and a stud as the other part. The fastener 58 has an insert portion 60 facing frontwardly and affixed to the insert 44 above the cap, and a pocket portion 62 affixed to the pocket front layer 30 inside the pocket and facing the garment substrate 32. When the insert 44 is in position within the pocket 24i the two strips of hook-and-loop fastener 58 are engaged with one another to retain the protective element 22 in place. The protective element 22 is thus securely fastened to the garment, without the need for constricting bands attached directly to the wearer, promoting greater mobility and comfort of the wearer. Moreover, the protective element 22 is readily removed for cleaning or replacement. As shown in FIGS. 3 and 4, the garment 28 may be provided with an adjustable band 64 which adjusts the fit of the pants leg 26 without itself fully encircling the wearer's leg 66. The band 64 is positioned on the interior of the garment, and may be formed of two straps 68, at least one of which may be of an elastic material. Both straps are fastened to the pants leg, and each has one part of a hook-and-loop fastener 70. The pants leg 26 may be formed with a side zipper 72 which runs upwardly from the lower end of the pants leg, such as on ski pants. The band 64 does not cross the zipper, but may be adjusted to tighten the rear of the pants leg before the zipper 72 is closed. The band 64 is positioned behind and just below the knee of the wearer. An alternative embodiment protective pad assembly 74 is shown in FIG. 5. The protective pad assembly 74 has a protective element 22 as in the assembly 20, but is used in connection with a garment 76 in which the front layer 78 does not overlie the garment substrate. Instead the front layer 78 is continuous with or is connected to the substrate, and the front layer is open at its rear to the wearer's limb 66 having the joint to be protected. The front layer 78 has an inner periphery 80 defining a central opening 82. As in the assembly 20, the stiff cap 42 is positioned frontwardly of the front layer 78, and the protective cushioning insert 44 extends rearwardly of the front layer, with the fabric of the front layer engaged between the flange 50 of the cap 42 and the cushioning insert 44. In the assembly 74, the cushioning insert 44 may engage directly against the wearer's leg, without the substrate of the garment intervening. The assembly 74 may also be provided with an exterior rear adjustable belt 84 in addition to or in place of the interior adjustable band 64 shown in FIG. 4. The adjustable belt 84 is attached to the exterior of the garment and is used to adjust the fit of the pants leg 86 of the garment, without itself fully encircling the wearer's leg 66. The adjustable belt 84 may be formed of two straps 88, at least one of which may be of an elastic material. Both straps 88 are fastened to the pants leg 86, and each has one part of a hook-and-loop fastener 70. An alternative embodiment protective pad assembly is shown in FIG. 6 which is similar to the assembly 20, but which has a garment assembly 89 with a hem or casing 91 around the inner periphery 90 of the front layer 92 surrounding the central opening 96 through which a drawstring 94 extends. The drawstring is an inelastic or elastic cord, and it works with a protective element 22 as described above (not shown in FIG. 6). By adjusting the drawstring 94 and tying the ends together or by using a conventional adjustable mechanical fastener where the ends come together, the diameter of the central opening 96 is reduced after the protective element 22 is in place, thereby securing the cap 42 to the front layer by sandwiching the constricted diameter opening between the cap and the cushioning insert 44 of the protective element. Alternatively, the cord may be an elastic member that may be inaccessible to the user. Such a device would simply permit the central opening to be stretched when the protective element cap is inserted through the central opening 96. The opening would then return to a smaller size under the force of the elastic member. Another alternative embodiment protective pad assembly 100 is shown in FIG. 7. The assembly 100 is similar to the assembly 20, except that the pocket 102 formed between the garment 104 substrate 106 and the front layer 108 having a central opening (not shown), has an opening at the top to permit the protective element 22 to be inserted between the front layer 108 and the substrate 106. The protective element 22 is installed by first folding up a pocket flap 112, and then inserting the element through an outer periphery opening 116. The cap 42 is then worked through the central opening, and secured in place as described with respect to the assembly 20. Once the element 22 is installed, the pocket flap 112 is closed, and secured in place with a conventional fastener, such as a two-part hook-and-loop fastener 114. It should be noted that although the pocket outer periphery opening 116 is shown in an upper edge, the opening and the covering flap 112 may alternatively be formed in a side or the bottom of the pocket. Alternatively, the adjustable belt may be provided as a single strap which passes through a loop fastened to the interior of the garment, and then attaching back to itself. Or, alternatively, the adjustable belt may be a single strap fastened at one end to the garment and having hook and loop fastener material which fastens to hook and loop fastener material on the garment interior itself. Or both these alternatives may be provided on the exterior of the garment. It should be noted that a protective element could have a single insert which is provided with two or more stiff caps, each one being engagable with a separate opening in the front layer of material. For example, as shown in FIG. 8, a combination knee and shin guard protective assembly 120 has a protective element 121 with a stiff knee cap 122 and a stiff shin cap 124 fastened to a single cushioning insert 126. The insert 126 is received within a pocket 128 defined between a front layer 130 of fabric and the front of the garment 132 pants leg 134. The front layer 130 has a top central opening 136 with which the knee cap 122 engages, and a lower central opening 138 with which the shin cap 124 engages. The knee cap 122 and shin cap 124 each have protruding flanges which engage the fabric of the front layer around the openings 136, 138 in a fashion similar to that described above with respect to the assembly 20. The protective element 121 may be provided with hook and loop fasteners 140 to engage with the inwardly facing surface of the front layer 130. It should be noted that the protective element may be formed as a single molded plastic part, rather than as an assembly of two parts. The protective element could be formed in the mold with two different plastic materials introduced into the mold, one material forming the more resilient insert, and one forming the stiffer cap. Alternatively, the stiff cap and the outer surface of the cushioning insert could be formed as a single part, for example of SANTOPRENE® plastic material, and the remainder of the cushioning insert could be formed as sheet of foam material glued or stitched to said single part. Another alternative embodiment protective element 142 is shown in FIG. 9. The protective element 142 has a cushioning insert 144 with a molded plastic front wall 146 to which a foam sheet 148 is adhered. The front wall 146 has a snap fit projection 150 which engages with a rearwardly extending snap fit protrusion 152 on the stiff cap 154. When used with the garment 104, shown in FIG. 7, the insert 144 is positioned within the pocket 102, and the cap is releasably snapped into place to secure the cap 154 to the insert 144, the front layer is thereby clamped between the cap and the cushioning insert 144. Alternatively, threaded structures may be formed on the insert and the cap to allow the two parts to be releasbly screwed together. It should be further noted that the protective element may engage with the front layer of material on the garment without engagement between the cap and the front layer. An alternative embodiment protective assembly 156, shown in FIG. 10, has a garment 158 with a front layer 160 having a central opening 162 which is slightly larger than the cap 164, for example, large enough to define about a 1/16 inch margin around the cap when it is installed. The cap 164 is fixed to a cushioning insert 166 which is received within the pocket 168. One half 170 of a two-part fastener is affixed to the frontwardly facing surface 172 of the insert 166 in a strip which encircles the cap 164, and the other half 174 of the two-part fastener is fixed to the interior of the front layer of fabric encircling the central opening 162. The two-part fastener is preferably VELCRO® hook and loop fastener, or multiple snap fasteners, or other conventional fastener. It should also be noted that a gap may be formed entirely on structure of the stiff cap to engage the inner periphery of the central opening in the front layer. Thus the cap can engage the front layer with a molded groove into which the front layer extends, without requiring the front layer to be engaged directly against the cushioning insert. It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to protective clothing in general, and more particularly to garments which incorporate pads for protection of the wearer's joints such as elbows and knees. There are many activities which require practitioners to take on cramped or reduced postures, such as crouching, crawling or lying prone, either momentarily or for extended periods. Moreover, it is sometimes necessary to assume these positions rapidly or unexpectedly. Kneeling and crawling, or collapsing to the knees, can be particularly injurious to the knees, either as a result of abrasion in the form of scraping, cutting, or puncturing, or as a result of impact or trauma. Flooring installers, carpenters, plumbers, and electricians are examples of tradesman who must occasionally or regularly spend time on their knees. Police officers, customs officials, and soldiers also are frequently required to kneel, crouch, or crawl, and often instantaneously in response to a sudden threat. Certain sporting and leisure activities can also lead to joint injuries if precautions are not taken. Conventional knee and elbow pads provide some measure of protection against impact by supplying a cushion over the joint. In addition, the force of a point impact can be distributed over a greater surface area by stiff shells which are fastened to the cushion. The stiff shells also provide protection against minor cuts and abrasions, while at the same time protecting the cushion itself from degradation. Elbow and knee pads are commonly of one of two types. Independent pads are mounted directly to the wearer's limbs by straps or belts. These devices offer the advantage of being securely attached in the vicinity of the joint to be protected, and being readily replaced for cleaning or repair. This type of pad is often employed where the wearer is otherwise lightly clad, such as in certain sporting activities. However, the tight elastic straps can be uncomfortable or can limit mobility. Moreover, the close-fitting pads can be especially hot during extended wear. In addition, the independent pads can be difficult to combine with other necessary garments, such as coveralls, fatigues, or jumpsuits, as the padding may, when used in combination with such clothing, restrict movement and ventilation and interfere with the garment. Furthermore, the hard shell of an independent pad, if worn interior to the garment, can result in the shredding or abrasion of the garment itself, which is caught between the hard shell of the pad and the hard exterior objects. If worn exterior to the garment, the pad can be excessively restrictive of the movement of the garment, and impair the mobility of the wearer. Garment-mounted pads are often more comfortable, and the hard shell of the pad worn on the exterior of the garment fabric serves to extend the life of the garment itself. Garment and pad wear may, however, progress at different rates, and it may be desirable to replace one and not the other. Or, it may be necessary to remove any foam padding in order to adequately wash the garment, or to safely subject the garment to drying heat. Some garments have pockets into which the foam pad is inserted, but if the hard shell is also inserted into this type of pocket, it would no longer provide protection for the garment fabric. What is needed is a replaceable garment mounted pad assembly, which includes both cushioning foam and an outwardly facing stiff shell, and which can be readily removed and reinstalled or replaced. | <SOH> SUMMARY OF THE INVENTION <EOH>The protective pad assembly of this invention has a stiff plastic cap which is attached to a resilient cushioning insert or pad in such a way that a stiff flange projects outwardly from the cap to define a gap between the flange and the cushioning pad which can receive the fabric of an outer layer of a centrally opening pocket formed on the garment. The outer layer is a sheet of material with a central opening, which is stitched to the fabric of a garment pants leg or arm on all four sides. The pocket cavity so defined may open only frontwardly through the central opening. The pad is flexible and larger than the central opening in the outer layer covering the knee or elbow. The pad can be inserted by flexing and compressing it into the circumferential hole so that the circumferential lip defining the hole in the outer layer is sandwiched between the shell and the pad. The cap and the pad are thus held in position, but both parts are readily removed for cleaning, repair, or replacement. An adjustable resilient strap may be attached to the interior of the garment to permit adjustment of the fit of the pad assembly. Alternatively, the central opening may be formed in a front layer without any backing garment substrate, so that the pad may be engaged directly by the wearer. It is an object of the present invention to provide a protective pad assembly for a garment which protects the garment and the wearer from abrasion and impact. It is another object of the present invention to provide a protective pad assembly which is readily removed and replaced, and which is connected to a garment, without being directly connected to the wearer. Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. | 20040708 | 20070703 | 20060112 | 97812.0 | A41D1300 | 1 | PATEL, TAJASH D | REMOVABLE GARMENT PROTECTIVE ASSEMBLY | SMALL | 0 | ACCEPTED | A41D | 2,004 |
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10,887,379 | ACCEPTED | Folding container | A folding container has a base, side support tubes upstanding from the corners of the base, and side panels located between the side support tubes and arranged to bound a storage space. Pivots are arranged to pivotally mount the side panels onto the side support tubes. The pivot for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base, and when in an unfolded state the side panels are substantially orthogonal to the base. | 1. A folding container comprising a base, side support means upstanding from the corners of said base, side panels located between said side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto said side support means, wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base, and when in an unfolded state the side panels are substantially orthogonal to the base. 2. The folding container according to claim 1 wherein the side support means include a two part columnar member comprising a first member adjacent said base and a second member remote from said base, said second member being pivotally secured to said first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels. 3. A folding container according to claim 1 wherein each side panel is pivotally mounted onto each of two adjacent side support means. 4. A folding container according to claim 3 wherein each side panel substantially occupies a space between adjacent support means onto which each said side panel is mounted. 5. A folding container according to claim 1, wherein said pivot means of each side panel comprises a male means cooperating with a slot in an edge of the side panel which is adjacent to the side support means when the container is unfolded, wherein said slot is terminated. 6. A folding container according to claim 5 wherein said male means is arranged to be a free sliding fit along the length of a mating slot in each of the panel edges. 7. A folding container according to claim 5 wherein said male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base. 8. A folding container according to claim 7 wherein a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels, a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel, a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel. 9. A folding container according to claim 1 wherein securing means are provided on the side panels to secure each individual side panel in the unfolded state in at least one of during and on completion of assembly. 10. A folding container according to claim 1 further comprising a cover panel pivotally mounted onto one of the side panels. 11. A folding container according to claim 1 wherein the side panels are formed from one of metal and plastic sheet material. 12. A folding container according to claim 1 wherein the base, side panels and support means form an integral unit. 13. A folding container comprising a base, side support means upstanding from the corners of said base, side panels located between said side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto said side support means, wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base, and when in an unfolded state the side panels are substantially orthogonal to the base, and wherein the side support means includes a two part columnar member comprising a first member adjacent said base and a second member remote from said base, said second member being pivotally secured to said first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels. 14. A folding container comprising a base, side support means upstanding from the corners of said base, side panels located between said side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto said side support means, wherein: the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base, and when in an unfolded state the side panels are substantially orthogonal to the base, said pivot means of each side panel comprises a male means cooperating with a slot in an edge of the side panel which is adjacent to the side support means when the container is unfolded, wherein said slot is terminated, said male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base, a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels, a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel, a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel. | BACKGROUND OF THE INVENTION 1) Field of the Invention This invention relates to a folding container and in particular to but not exclusively to a packing case, a shipping crate or a freight container. 2) Description of the Related Art Containers are required for a variety of purposes and, in many circumstances, such as moving automotive parts or possessions between houses or flats and in the case of mobile offices, it is necessary for the container to be sufficiently sturdy to protect the container contents from damage when it is moved or accidentally knocked. However, such a container is unlikely to be in constant use, and as a result it would be advantageous if it could be stored in a flat condition when it is not required. Containers having opposing side walls which fold onto a base panel have been described in DE 1 144 178 and DE 2 139 147. U.S. Pat. No. 3,941,271 relates to a collapsible receptacle having inwardly and outwardly directed projections on a base panel frame and sidewalls. The outwardly directed projection of the sidewall overlaps the inwardly directed projection of the base panel frame to maintain the receptacle in the assembled non-collapsed condition such that a tilting of the sidewalls is necessary to raise the sidewall. U.S. Pat. No. 5,642,830 describes a container having top and bottom members, and columnar members which are received in the top and bottom members when the container is in the assembled condition. When the container is disassembled the columnar members and side members may be stored inside the top and bottom members which are jointed together so that the disassembled container forms an integral unit. A collapsible container is described in EP 1 028 061 having side panels associated with a base panel and movable between a collapsed and an assembled condition. The container is releasably retained in the assembled condition by side supports engaging adjacent side panels, the side supports comprising upright members demountably secured to the base panel and received and retained by a receptacle secured at or adjacent to the corners of the base panel. There remains, however, a need for a compact, economical folding container design which can be readily converted from a folded to an unfolded state and which is adaptable for industrial use e.g. in shipping and intermodal containers. SUMMARY OF THE INVENTION A preferred feature of the present invention is directed to a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means, wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel. In a preferred embodiment the side support means includes a two part columnar member comprising a first member adjacent to the base panel and a second member remote from the base panel, the second member being pivotally secured to the first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels. Preferably each side panel is pivotally mounted onto each of two adjacent side support means. More preferably each side panel substantially occupies a space between adjacent support means onto which each side panel is mounted. Preferably the pivot means of each side panel comprises a male means cooperating with a slot in an edge of the side panel which is adjacent to the side support means when the container is unfolded, wherein said slot is terminated. The male means may be arranged to be a free sliding fit along the length of a mating slot in each of the panel edges. Preferably the male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base panel. In a preferred embodiment a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels, a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel, a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel. Securing means may be provided on the side panels to secure each individual side panel in the unfolded state. A cover panel may be pivotally mounted onto one of the side panels. Preferably the side panels are formed from metal or plastic sheet material. In a particularly preferred embodiment the base panel, side panels and support means form an integral unit. In another embodiment the invention is directed to a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means, wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel, and the side support means includes a two part columnar member comprising a first member adjacent to the base panel and a second member remote from the base panel, the second member being pivotally secured to the first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels. In a further embodiment the invention provides for a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means, wherein: the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel, the pivot means of each side panel is provided by a slot in each edge of the side panel which are adjacent to the side support means when the container is unfolded, said slot being terminated, and male means located on the side support means arranged to engage with the slots, the male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base panel, and a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels, a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel, a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further understood by reference to the accompanying drawings showing an exemplary embodiment thereof. FIG. 1 is a perspective view of a preferred embodiment of a container in accordance with this invention in a folded state, FIG. 2 is a top view of the container in an unfolded state, FIG. 3 is a perspective view of a side panel of the container, FIG. 4 is a perspective view of a base panel of the container, FIGS. 5 and 6 show mutually orthogonal side views of a side support means in an unfolded state, FIGS. 7a and 7b show side views of the side support means in different operational states thereof, FIG. 8 is a perspective view of the container shown in FIG. 1 with the side support means partially unfolded, FIGS. 9, 10 and FIGS. 11,12 respectively show alternative constructions for moving a side panel from a folded to an unfolded state, FIGS. 13 shows a side panel onto which a cover panel is to be mounted, FIGS. 14a and 14b show a pivoting arm of the side panel of FIG. 13 in different operational states, FIGS. 15 and 16 show a cover panel being moved from a folded to an unfolded state, and FIG. 17 shows the fully unfolded container with side panels secured. In the Figures like reference numerals have the like parts. DESCRIPTION OF THE PREFERRED EMBODIMENTS The folded container illustrated in FIG. 1 has a substantially rectangular base panel 1, four side panels 2 stacked on top of the base panel, and four two-part side support tubes 3 upstanding from the corners of the base panel, each support tube having a lower member 4 adjacent to the base panel and an upper member 5 remote from the base panel. The support tubes 3 have a circular cross section but it will be understood that other suitable cross sections may be used. The upper member 5 is pivotally secured to the lower member 4 and is folded onto the surface 6 of the upper stacked side panel. The base panel 1, side panels 2 and side support tubes 3 are formed from metal sheet material. Referring to FIG. 2, each of the side panels 2 in the unfolded container occupies the space between two adjacent side support tubes 3 onto which the side panels are pivotally mounted, as will now be described. FIG. 3 shows a side panel 2 having a terminated longitudinal slot 7 in one edge 8. A similar slot is located in the opposing edge of the side panel. Four pairs of laterally projecting cylindrical pins 9, 10, 11 and 12 are located on the lower members 4 of adjacent support tubes as shown in FIG. 4. Each pair of pins is located at a different distance from the base panel with respect to any of the other pairs. Preferably the first pair of pins 9 closest to the base panel are located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent side panels, the second pair of pins 10 at a distance 2T-S/2 from the base panel, the third pair of pins 11 at a distance 3T-S/2 from the base panel, and the fourth pair of pins 12 furthest from the base panel are at a distance 4T-S/2 from the base panel. Each side panel 2 is mounted onto adjacent support tubes 3 by engagement of the relevant pair of slots 7 in the side panel edges 8 with a corresponding pair of cylindrical pins 12 as shown in FIG. 11. Each slot 7 is closed at opposing ends to retain the pin 12 associated therewith. The pins 12 engage with the slots 7 in a free sliding fashion so that the side panel 2 can undergo translational movement in the slot plane as well as pivotal movement about the pin axis. The spacing of the pairs of pins 12 from the base panel 1 ensures that in the folded state the side panels 2 stack together in different horizontal planes overlying the base panel 1 as shown in FIG. 1. Referring to FIGS. 5 and 7a, the upper member 5 of a side support tube 3 has an extension 50 formed by a pair of opposed flat surfaces 13 projecting from its lower end with a longitudinal opening 14 therein. Part of the wall of the lower member 4 of the side support tube 3 projects vertically from its upper end to form two opposing end pieces 15, each end piece having a circular hole 16 located therein as shown in the mutually orthogonal side views of FIGS. 5 and 6. The opposing end pieces 15 define a recess 17, which partially extends into the tubular lower member 4, and which is dimensioned so as to receive the extension 50 of the upper member 5 in close fitting engagement, with the holes 16 aligning with the longitudinal opening 14 of the extension 50. A cylindrically cross sectioned bar 18 projects laterally through opposing holes 16 and opening 14 so as to retain the upper member 5 of the side support within the lower member 4. The bar 18 is in sliding engagement with the extension 50 so that the upper member 5 can be vertically extended with respect to the lower member 4 (FIG. 7a). Referring to FIGS. 7a and 7b the side support 3 can be moved from a substantially vertical unfolded position to a folded position substantially perpendicular to the lower member 4 by extending the upper member 5 until the lower edge 19 of the extension 50 is clear of the upper edge 20 of the lower member followed by rotation of the upper member 5 about the axis of the bar 18. In erecting the container from a collapsed, folded condition, a first step is to rotate the upper members 5 of the four side support tubes 3 in turn from the folded position, where the upper members 5 are lying on the surface 6 of the uppermost side panel 2 as shown in FIG. 1, to the unfolded position where the upper members 5 are substantially vertical and form continuous columns with the corresponding lower members 4 as shown in FIG. 8. In a second step each side panel 2 of the container is moved in turn from a folded to an unfolded position and preferably fastened to adjacent side support tubes 3 before the next side panel is unfolded. There are two alternative methods for performing this step as shown in FIGS. 9, 10 and in FIGS. 1 1, 12 respectively. In a first method the edge 21 of the uppermost side panel 2 furthest from the side support tubes 3 onto which it is mounted is raised and rotated upwards towards the side support tubes 3 (shown in FIG. 9). When the side panel 2 is in a substantially vertical position, with the opposing edges 8 parallel to the corresponding side support tubes 3, the side panel 2 is lowered vertically towards the container base panel 1 and into the unfolded position with a bottom edge 22 of the side panel resting on the upper surface of the base panel 1 (shown in FIG. 10). The side panel 2 is then fastened to adjacent side support tubes 3 by sliding engagement of bolts 34 secured to the side panel 2 within corresponding recesses 37 in the side support tubes 3. The process is repeated for the remaining side panels in turn. In a second method the uppermost side panel 2 is slid in a substantially horizontal plane outwards between the side support tubes 3 onto which it is mounted (shown in FIG. 11). When the side panel 2 has been translated in this plane as far from the side support tubes 3 as the slots 7 in the edges 8 will allow, the edge 23 of the side panel 2 furthest from the side support tubes 3 is raised and rotated upwards towards the side support tubes 3 (shown in FIG. 12). When the side panel 2 is in a substantially vertical position, with the opposing pivoting edges 8 parallel to the corresponding side support tubes 3, the side panel 2 is lowered vertically towards the container base panel 1 and into the unfolded position with the bottom edge of the side panel resting on the upper surface of the base panel 1. The side panel 2 is then fastened to adjacent side support tubes 3 as described in the first method. The process is repeated for the remaining side panels in turn. A cover panel 30 is pivotally mounted onto the side panel 2 that is uppermost when the container is in the folded state by pivoted arms 24 as shown in FIGS. 13-15. Each arm 24 has a pin 29 arranged to co-operate with a slot 31 in opposing edges 32 of the cover panel 30. The arm 24 also has an arcuate slot 25 cooperating with a pin 27 extending laterally through the curved slot 25 and in free sliding engagement therein. The arm 24 is secured to the edge 8 of the side panel 2 by a pin 26 (FIG. 14a). The arm 24 can be partially rotated from a vertical position by pivoting about the pin 26 and sliding of the pin 27 through the slot 25 as shown in FIG. 14b. When all four side panels 2 have been moved from the folded to the unfolded position the upper edge 33 of the cover panel 30 is moved from a position substantially parallel to the major face of the side panel onto which it is mounted to an angled position by rotation of the arm 24 about the pin 26 as described above as shown in FIG. 15. The cover panel 30 is then moved upwards and away from the side panel 2 as shown in FIG. 16 by rotation about the pin 24 and sliding of the pin 24 along the slot 31 in the edge 32 of the cover panel 30 until it is resting on the upper edges of a front side panel 35 and a rear side panel 36 and substantially parallel to the container base panel 1 as shown in FIG. 17. The container is unfolded to a collapsed condition by reversing the steps described above. The person of ordinary skill in the art will appreciate that many modifications to the described embodiment are possible without departing from the spirit and scope of the invention defined in the appended claims. For instance wheels can be adapted to the base panel; the side support tubes may have any suitable transverse cross section; although the panels are preferably formed from metal, they could be formed of plastics or any other suitable material; the container can be suited for different uses and be of different sizes. | <SOH> BACKGROUND OF THE INVENTION <EOH>1) Field of the Invention This invention relates to a folding container and in particular to but not exclusively to a packing case, a shipping crate or a freight container. 2) Description of the Related Art Containers are required for a variety of purposes and, in many circumstances, such as moving automotive parts or possessions between houses or flats and in the case of mobile offices, it is necessary for the container to be sufficiently sturdy to protect the container contents from damage when it is moved or accidentally knocked. However, such a container is unlikely to be in constant use, and as a result it would be advantageous if it could be stored in a flat condition when it is not required. Containers having opposing side walls which fold onto a base panel have been described in DE 1 144 178 and DE 2 139 147. U.S. Pat. No. 3,941,271 relates to a collapsible receptacle having inwardly and outwardly directed projections on a base panel frame and sidewalls. The outwardly directed projection of the sidewall overlaps the inwardly directed projection of the base panel frame to maintain the receptacle in the assembled non-collapsed condition such that a tilting of the sidewalls is necessary to raise the sidewall. U.S. Pat. No. 5,642,830 describes a container having top and bottom members, and columnar members which are received in the top and bottom members when the container is in the assembled condition. When the container is disassembled the columnar members and side members may be stored inside the top and bottom members which are jointed together so that the disassembled container forms an integral unit. A collapsible container is described in EP 1 028 061 having side panels associated with a base panel and movable between a collapsed and an assembled condition. The container is releasably retained in the assembled condition by side supports engaging adjacent side panels, the side supports comprising upright members demountably secured to the base panel and received and retained by a receptacle secured at or adjacent to the corners of the base panel. There remains, however, a need for a compact, economical folding container design which can be readily converted from a folded to an unfolded state and which is adaptable for industrial use e.g. in shipping and intermodal containers. | <SOH> SUMMARY OF THE INVENTION <EOH>A preferred feature of the present invention is directed to a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means, wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel. In a preferred embodiment the side support means includes a two part columnar member comprising a first member adjacent to the base panel and a second member remote from the base panel, the second member being pivotally secured to the first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels. Preferably each side panel is pivotally mounted onto each of two adjacent side support means. More preferably each side panel substantially occupies a space between adjacent support means onto which each side panel is mounted. Preferably the pivot means of each side panel comprises a male means cooperating with a slot in an edge of the side panel which is adjacent to the side support means when the container is unfolded, wherein said slot is terminated. The male means may be arranged to be a free sliding fit along the length of a mating slot in each of the panel edges. Preferably the male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base panel. In a preferred embodiment a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels, a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel, a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel. Securing means may be provided on the side panels to secure each individual side panel in the unfolded state. A cover panel may be pivotally mounted onto one of the side panels. Preferably the side panels are formed from metal or plastic sheet material. In a particularly preferred embodiment the base panel, side panels and support means form an integral unit. In another embodiment the invention is directed to a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means, wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel, and the side support means includes a two part columnar member comprising a first member adjacent to the base panel and a second member remote from the base panel, the second member being pivotally secured to the first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels. In a further embodiment the invention provides for a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means, wherein: the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel, the pivot means of each side panel is provided by a slot in each edge of the side panel which are adjacent to the side support means when the container is unfolded, said slot being terminated, and male means located on the side support means arranged to engage with the slots, the male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base panel, and a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels, a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel, a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel. | 20040708 | 20080325 | 20060112 | 67971.0 | B65D612 | 0 | BRADEN, SHAWN M | FOLDING CONTAINER | SMALL | 0 | ACCEPTED | B65D | 2,004 |
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10,887,426 | ACCEPTED | Ion implantation ion source, system and method | An ion implantation device for vaporizing decaborane and other heat-sensitive materials via a novel vaporizer and vapor delivery system and delivering a controlled, low-pressure drop flow of vapors, e.g. decaborane, into the ion source. The ion implantation device includes an ion source which can operate without an arc plasma, which can improve the emittance properties and the purity of the beam and without a strong applied magnetic field, which can improve the emittance properties of the beam. The ion source is configured so that it can be retrofit into the ion source design space of an existing Bernas source-based ion implanters and the like or otherwise enabling compatibility with other ion source designs. | 1. An ion source for use with an ion implant device, the ion source comprising: an ionization chamber defined by a plurality of side walls defining an ionization volume, one of said sidewalls including an ion extraction aperture for enabling an ion beam to be extracted from said ionization chamber along a predetermined axis defining an ion beam axis; an electron beam source and an aligned beam receptor configured relative to said ionization chamber to cause an electron beam to be directed across the ionization volume of said ionization chamber in a direction generally perpendicular to said ion beam axis for ionizing gas in the ionization chamber by direct electron impact ionization by energetic electrons; and a gas source in fluid communication with said ionization chamber. 2-65. (Canceled). 66. A multi-mode ion source comprising: an ion source incorporating an ionization chamber for ionizing gas species and configured to have at least two discrete modes of operation, namely, an arc discharge mode, and a non-arc discharge mode. 67. The ion source as recited in claim 66, further including a cooling mechanism, wherein said ionization chamber is actively cooled by said cooling mechanism. 68. The ion source as recited in claim 67, further including a second member, wherein said cooling mechanism comprises said ionization chamber being disposed in conductive heat transfer relationship with a second member, the temperature of said second member being actively controlled defining a temperature controlled body. 69. The ion source as recited in claim 68, further including a gas interface, wherein said conductive heat transfer relationship includes a gas interface between one or more walls of said ionization chamber and said temperature controlled body. 70. The ion source as recited in claim 68, wherein said temperature controlled body is water-cooled. 71. The ion source as recited in claim 69, wherein said temperature controlled body is water cooled. 72. The ion source as recited in claim 68, wherein said temperature controlled body is heated by a heater element. 73. The ion source as recited in claim 68, wherein the temperature control is accomplished by a control system. 74. The ion source as recited in claim 66, wherein said non-arc discharge mode is defined by electron impact ionization resulting in a low plasma density within said ionization chamber of said ion source. 75. The ion source as recited in claim 66, wherein said arc discharge mode is defined by the formation of a plasma by said arc discharge within said ionization chamber of said ion source, the plasma density thus formed being substantially higher than that obtained in said non-arc discharge mode. 76. The ion source as recited in claim 74, wherein said ion source includes a system for injection of a directed beam of electrons defining an electron beam into said ionization chamber of said ion source resulting in electron impact ionization in said non arc discharge mode. 77. The ion source as recited in claim 75, wherein said ion source includes an electron source in direct contact with said plasma within said ionization chamber such that said plasma is sustained by said electron source in said arc discharge mode. 78. The ion source as recited in claim 76, wherein said system includes an electron source for generating said electron beam. 79. The ion source as recited in claim 78, wherein said electron source is a thermionic emitter of electrons. 80. The ion source as recited in claim 79, wherein said thermionic emitter is a hot filament. 81. The ion source as recited in claim 79, wherein said thermionic emitter is an indirectly heated cathode. 82. The ion source as recited in claim 77, wherein said electron source includes a thermionic emitter of electrons. 83. The ion source as recited in claim 81, wherein said electron source is external to the ionization chamber of said ion source. 84. The ion source as recited in claim 82, wherein said electron source is external to the ionization chamber of said ion source. 85. The ion source as recited in claim 83 further including a cooled support structure and, wherein said electron source is mounted to a cooled support structure. 86. The ion source as recited in claim 84, further including a cooled support structure and wherein said electron source is mounted to said cooled support structure. 87. The ion source as recited in claim 85, wherein said cooled support structure is configured to be cooled by deionized water. 88. The ion source as recited in claim 86, wherein said cooled support structure is cooled by deionized water. 89. The ion source as recited in claim 85, wherein said cooled support structure is configured to be cooled through a gas interface between said support structure and an adjacent temperature-controlled body. 90. The ion source as recited in claim 86, wherein said cooled support structure is cooled through a gas interface between said support structure and an adjacent temperature-controlled body. 91. The ion source as recited in claim 66, further including an electrode, the polarity of the said electrode being positive with respect to said ionization chamber during operation in non-arc discharge mode, and negative with respect to said ionization chamber in arc discharge mode. 92. The ion source as recited in claim 91, wherein in said arc discharge mode, said electrode functions as an electron repeller. 93. The ion source as recited in claim 66, wherein the ionization chamber of said ion source contains an axial magnetic field. 94. The ion source as recited in claim 93, wherein said axial field provides confinement of the electron beam in non-arc discharge mode, and enables operation in a reflex geometry in arc discharge mode. 95. The ion source as recited in claim 82, wherein said thermionic emitter is a hot filament. 96. The ion source as recited in claim 82, wherein said thermionic emitter is an indirectly heated cathode. 97. A multi mode ion source comprising: an ion source incorporating an ionization chamber for ionizing gas species and configured to have at least two discrete modes of operation: namely, a reflex mode and a non-reflex mode of operation. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority of and benefit of U.S. Provisional Patent Application No. 60/170,473 filed on Dec. 13, 1999, U.S. Provisional Patent Application No. 60/250,080 filed on Nov. 30, 2000 and PCT Patent Application No. PCT/US00/33786 filed on Dec. 13, 2000. BACKGROUND OF THE INVENTION 1. Field of Invention The invention provides production-worthy ion sources and methods capable of using new source materials, in particular, heat-sensitive materials such as decaborane (B10H14), and hydrides and dimer-containing compounds novel to the ion implantation process, to achieve new ranges of performance in the commercial ion implantation of semiconductor wafers. The invention enables shallower, smaller and higher densities of semiconductor devices to be manufactured, particularly in Complementary Metal-Oxide Semiconductor (CMOS) manufacturing. In addition to enabling greatly enhanced operation of new ion implanter equipment in the manufacture of semiconductor devices, the invention enables the new ion source to be retrofit into the existing fleet of ion implanters with great capital cost savings. Embodiments of the invention uniquely implant decaborane and the other dopant materials in particularly pure ion beams, enabling a wide range of the needs of a fabrication facility to be met. Various novel constructional, operational and process features that contribute to the cost-effectiveness of the new technology are applicable as well to prior technology of the industry. 2. Description of the Prior Art As is well known, ion implantation is a key technology in the manufacture of integrated circuits (ICs). In the manufacture of logic and memory ICs, ions are implanted into silicon or GaAs wafers to form transistor junctions, and to dope the well regions of the p-n junctions. By selectively controlling the energy of the ions, their implantation depth into the target wafer can be selectively controlled, allowing three-dimensional control of the dopant concentrations introduced by ion implantation. The dopant concentrations control the electrical properties of the transistors, and hence the performance of the ICs. A number of dopant feed materials have previously been used, including As, Ar, B, Be, C, Ga, Ge, In, N, P, Sb and Si. For those species which are of solid elemental form, many are obtainable in gaseous molecular form, such as fluoride compounds that are ionizable in large quantities at significantly elevated temperatures. The ion implanter is a manufacturing tool which ionizes the dopant-containing feed materials, extracts the dopant ions of interest, accelerates the dopant ions to the desired energy, filters away undesired ionic species, and then transports the dopant ions of interest to the wafer at the appropriate energy for impact upon the wafer. The presence in the implanter of certain elements, such as the disassociated element fluorine, is detrimental to the implanted wafers, but, despite such drawbacks, trace amounts of such contaminants have been tolerated in many contexts, in the interest of achieving production-worthy throughput volume. Lower contaminant levels from what is now achievable is desired. In a complex relationship, overall, a number of variables must be controlled in order to achieve a desired implantation profile for a given ion implantation process: The nature of the dopant feed material (e.g., BF3 gas) Dopant ion species (e.g., B+) Ion energy (e.g., 5 keV) Chemical purity of the ion beam (e.g., <0.01% energetic contaminants) Isotopic purity of the ion beam (e.g., ability to discriminate between 113In and 115In) Energy purity of the ion beam (e.g., <2% full width at half maximum, i.e. FWHM) Angular divergence and spatial extent of the beam on the wafer Total dose (e.g., 1015 atoms/cm2) implanted on the wafer Uniformity of the dose (e.g., ±1% variation in the implanted density over the total wafer surface area). These variables affect the electrical performance, minimum manufacturable size and maximum manufacturable density of transistors and other devices fabricated through ion implantation. A typical commercial ion implanter is shown in schematic in FIG. 1. The ion beam I is shown propagating from the ion source 42 through a transport (i.e. “analyzer”) magnet 43, where it is separated along the dispersive (lateral) plane according to the mass-to-charge ratio of the ions. A portion of the beam is focused by the magnet 43 onto a mass resolving aperture 44. The aperture size (lateral dimension) determines which mass-to-charge ratio ion passes downstream, to ultimately impact the target wafer 55, which typically may be mounted on a spinning disk 45. The smaller the mass resolving aperture 44, the higher the resolving power R of the implanter, where R=M/ΔM (M being the nominal mass-to-charge ratio of the ion and ΔM being the range of mass-to-charge ratios passed by the aperture 44). The beam current passing aperture 44 can be monitored by a moveable Faraday detector 46, whereas a portion of the beam current reaching the wafer position can be monitored by a second Faraday detector 47 located behind the disk 45. The ion source 42 is biased to high voltage and receives gas distribution and power through feedthroughs 48. The source housing 49 is kept at high vacuum by source pump 50, while the downstream portion of the implanter is likewise kept at high vacuum by chamber pump 51. The ion source 42 is electrically isolated from the source housing 49 by dielectric bushing 52. The ion beam is extracted from the ion source 42 and accelerated by an extraction electrode 53. In the simplest case (where the source housing 49, implanter magnet 43, and disk 45 are maintained at ground potential), the final electrode of the extraction electrode 53 is at ground potential and the ion source is floated to a positive voltage Va, where the beam energy E=qVa and q is the electric charge per ion. In this case, the ion beam impacts the wafer 55 with ion energy E. In other implanters, as in serial implanters, the ion beam is scanned across a wafer by an electrostatic or electromagnetic scanner, with either a mechanical scan system to move the wafer or another such electrostatic or electromagnetic scanner being employed to accomplish scanning in the orthogonal direction. A part of the system of great importance in the technology of ion implantation is the ion source. FIG. 2 shows diagrammatically the “standard” technology for commercial ion sources, namely the “Enhanced Bernas” arc discharge ion source. This type of source is commonly the basis for design of various ion implanters, including high current, high energy, and medium current ion implanters. The ion source a is mounted to the vacuum system of the ion implanter through a mounting flange b which also accommodates vacuum feedthroughs for cooling water, thermocouples, dopant gas feed, N2 cooling gas, and power. The dopant gas feed c feeds gas, such as the fluorides of a number of the desired dopant species, into the arc chamber d in which the gas is ionized. Also provided are dual vaporizer ovens e, f inside of the mounting flange in which solid feed materials such as As, Sb2O3, and P may be vaporized. The ovens, gas feed, and cooling lines are contained within a water cooled machined aluminum block g. The water cooling limits the temperature excursion of the aluminum block g while the vaporizers, which operate between 100° C. and 800° C., are active, and also counteracts radiative heating by the arc chamber d when the ion source is active. The arc chamber d is mounted to, but designedly is in poor thermal contact with, the aluminum block g. The ion source a employs an arc discharge plasma, which means that it operates by sustaining within a defined chamber volume a generally narrow continuous electric arc discharge between hot filament cathode h, residing within the arc chamber d, and the internal walls of the arc chamber d. The arc produces a narrow hot plasma comprising a cloud of primary and secondary electrons interspersed with ions of the gas that is present. Since this arc can typically dissipate in excess of 300 W energy, and since the arc chamber d cools only through radiation, the arc chamber in such Bernas ion sources can reach a temperature of 800° C. during operation. The gas is introduced to arc chamber d through a low conductance passage and is ionized through electron impact with the electrons discharged between the cathode h and the arc chamber d and, as well, by the many secondary electrons produced by the arc discharge. To increase ionization efficiency, a substantial, uniform magnetic field i is established along the axis joining the cathode h and an anticathode j by externally located magnet coils, 54 as shown in FIG. 1. This provides confinement of the arc electrons, and extends the length of their paths. The anticathode j (sometimes referred to as a “repeller”) located within the arc chamber d but at the end opposite the cathode h is typically held at the same electric potential as the cathode h, and serves to reflect the arc electrons confined by the magnetic field i back toward the cathode h, from which they are repelled back again, the electrons traveling repeatedly in helical paths. The trajectory of the thus-confined electrons results in a cylindrical plasma column between the cathode h and anticathode j. The arc plasma density within the plasma column is typically high, on the order of 1012 per cubic centimeter; this enables further ionizations of the neutral and ionized components within the plasma column by charge-exchange interactions, and also allows for the production of a high current density of extracted ions. The ion source a is held at a potential above ground (i.e., above the potential of the wafer 55) equal to the accelerating voltage Va of the ion implanter: the energy, E, of the ions as they impact the wafer substrate is given by E=qVa, where q is the electric charge per ion. The cathode h of such a conventional Bernas arc discharge ion source is typically a hot filament or an indirectly-heated cathode which thermionically emits electrons when heated by an external power supply. It and the anticathode are typically held at a voltage Vc between 60V and 150V below the potential of the ion source body Va. Once an arc discharge plasma is initiated, the plasma develops a sheath adjacent the exposed surface of the cathode h within chamber d. This sheath provides a high electric field to efficiently extract the thermionic electron current for the arc; high discharge currents (e.g., up to 7 A) can be obtained by this method. The discharge power P dissipated in the arc chamber is P=DVc, typically hundreds of watts. In addition to the heat dissipated by the arc, the hot cathode h also transfers power to the walls of the arc chamber d. Thus, the arc chamber d provides a high temperature environment for the dopant arc plasma, which boosts ionization efficiency relative to a cold environment by increasing the gas pressure within the arc chamber d, and by preventing substantial condensation of dopant material on the hot chamber walls. If the solid source vaporizer ovens e or f of the Bernas arc discharge ion source are used, the vaporized material feeds into the arc chamber d with substantial pressure drop through narrow vaporizer feeds k and l, and into plenums m and n. The plenums serve to diffuse the vaporized material into the arc chamber d, and are at about the same temperature as the arc chamber d. Radiative thermal loading of the vaporizers by the arc chamber also typically prevents the vaporizers from providing a stable temperature environment for the solid feed materials contained therein below about 200° C. Thus, typically, only solid dopant feed materials that both vaporize at temperatures >200° C. and decompose at temperatures >800° C. (the temperature of the walls of the ionization chamber of a typical Bernas source) can be successfully vaporized and introduced by this method. A very significant problem which currently exists in the ion implantation of semiconductors is the limitation of production-worthy ion implantation implanters that prevents effective implanting of dopant species at low (e.g., sub-keV) energies at commercially desired rates. One critically important application which utilizes low-energy dopant beams is the formation of shallow transistor junctions in CMOS manufacturing. As transistors shrink in size to accommodate more transistors per IC according to a vital trend, the transistors must be formed closer to the surface of the target wafer. This requires reducing the velocity, and hence the energy, of the implanted ions, so that they deposit at the desired shallow level. The most critical need in this regard is the implantation of low-energy boron, a p-type dopant, into silicon wafers. Since boron atoms have low mass, at a given energy for which the implanter is designed to operate, they must have higher velocity and will penetrate deeper into the target wafer than other p-type dopants; therefore there is a need for boron to be implanted at lower energies than other species. Ion implanters are relatively inefficient at transporting low-energy ion beams due to space charge within the ion beam, the lower the energy, the greater the problem. The space charge in low energy beams causes the beam cross-section area (i.e. its “profile”) to grow larger as the ions proceed along the beam line (there is “beam blow-up”). When the beam profile exceeds the profile for which the implanter's transport optics have been designed, beam loss through vignetting occurs. For example, at 500 eV transport energy, many ion implanters currently in use cannot transport enough boron beam current to be commercially efficient in manufacturing; i.e., the wafer throughput is too low because of low implantation dose rate. In addition, known ion sources rely on the application of a strong magnetic field in the source region. Since this magnetic field also exists to some extent in the beam extraction region of the implanter, it tends to deflect such a low-energy beam and substantially degrade the emittance properties of the beam, which further can reduce beam transmission through the implanter. An approach has been proposed to solve the problem of low-energy boron implantation: molecular beam ion implantation. Instead of implanting an ion current I of atomic B+ ions at an energy E, a decaborane molecular ion, B10Hx+, is implanted at an energy 10×E and an ion current of 0.10×I. The resulting implantation depth and dopant concentration (dose) of the two methods have been shown to be generally equivalent, with the decaborane implantation technique, however, having significant potential advantages. Since the transport energy of the decaborane ion is ten times that of the dose-equivalent boron ion, and the ion current is one-tenth that of the boron current, the space charge forces responsible for beam blowup and the resulting beam loss can potentially be much reduced relative to monatomic boron implantation. While BF3 gas can be used by conventional ion sources to generate B+ ions, decaborane (B10H14) must be used to generate the decaborane ion B10Hx+. Decaborane is a solid material which has a significant vapor pressure, on the order of 1 Torr at 20° C., melts at 100° C., and decomposes at 350° C. To be vaporized through preferred sublimination, it must therefore be vaporized below 100° C., and it must operate in a production-worthy ion source whose local environment (walls of the ionization chamber and components contained within the chamber) is below 350° C. to avoid decomposition. In addition, since the B10H14 molecule is so large, it can easily disassociate (fragment) into smaller components, such as elemental boron or diborane (B2H6), when subject to charge-exchange interactions within an arc discharge plasma, hence it is recognized that conventionally operated Bernas arc plasma sources can not be employed in commercial production, and that ionization should be obtained primarily by impact of primary electrons. Also, the vaporizers of current ion sources cannot operate reliably at the low temperatures required for decaborane, due to radiative heating from the hot ion source to the vaporizer that causes thermal instability of the molecules. The vaporizer feed lines k, l can easily become clogged with boron deposits from decomposed vapor as the decaborane vapor interacts with their hot surfaces. Hence, the present production-worthy implanter ion sources are incompatible with decaborane ion implantation. Prior efforts to provide a specialized decaborane ion source have not met the many requirements of production-worthy usage. More broadly, there are numerous ways in which technology that has been common to the industry has had room for improvement. Cost-effective features, presented here as useful in implementing the new technology, are applicable to implementation of the established technology as well. SUMMARY OF THE INVENTION Various aspects of the invention provide improved approaches and methods for efficiently: Vaporizing decaborane and other heat-sensitive materials via a novel vaporizer and vapor delivery system; Delivering a controlled, low-pressure drop flow of vapors, e.g. decaborane, into the ion source; Ionizing the decaborane into a large fraction of B10Hx+; Preventing thermal dissociation of decaborane; Limiting charge-exchange and low energy electron-induced fragmentation of B10Hx+; Operating the ion source without an arc plasma, which can improve the emittance properties and the purity of the beam; Operating the ion source without use of a strong applied magnetic field, which can improve the emittance properties of the beam; Using a novel approach to produce electron impact ionizations without the use of an arc discharge, by incorporation of an externally generated, broad directional electron beam which is aligned to pass through the ionization chamber to a thermally isolated beam dump; Providing production-worthy dosage rates of boron dopant at the wafer; Providing a hardware design that enables use also with other dopants, especially using novel hydride, dimer-containing, and indium- or antimony-containing temperature-sensitive starting materials, to further enhance the economics of use and production worthiness of the novel source design and in many cases, reducing the presence of contaminants; Matching the ion optics requirements of the installed base of ion implanters in the field; Eliminating the ion source as a source of transition metals contamination, by using an external and preferably remote cathode and providing an ionization chamber and extraction aperture fabricated of non-contaminating material, e.g. graphite, silicon carbide or aluminum; Enabling retrofit of the new ion source into the ion source design space of existing Bernas source-based ion implanters and the like or otherwise enabling compatibility with other ion source designs; Using a control system in retrofit installations that enables retention of the installed operator interface and control techniques with which operators are already familiar; Enabling convenient handling and replenishment of the solid within the vaporizer without substantial down-time of the implanter; Providing internal adjustment and control techniques that enable, with a single design, matching the dimensions and intensity of the zone in which ionization occurs to the beam line of the implanter and the requirement of the process at hand; Providing novel approaches, starting materials and conditions of operation that enable the making of future generations of semiconductor devices and especially CMOS source/drains and extensions, and doping of silicon gates; And generally, providing features, relationships and methods that achieve production-worthy ionization of decaborane and numerous other dopant feed materials many of which are novel to ion implantation, to meet the practical needs of fabrication facilities. Embodiments of the present invention can enhance greatly the capability of new ion implantation systems and can provide a seamless and transparent upgrade to end-users' existing implanters. In particular, aspects of the invention are compatible with current ion implantation technology, such that an ion source constructed according to the invention can be retrofitted into the existing fleet of ion implanters currently installed in expensive fabrication plants. Embodiments of the invention are (1) constructed, sized and arranged such that they fit into the existing ion source space of commercial implanters, and 2) employ a novel control system for the ion source which can physically replace the existing ion source controller, without further modification of the implanter controls and qualified production techniques. According to one aspect of the invention, an ion source capable of providing ions in commercial ion current levels to the ion extraction system of an ion implanter is provided, the ion source comprising an ionization chamber defined by walls enclosing an ionization volume, there being an ion extraction aperture in a side wall of the ionization chamber, the aperture having a length and width sized and arranged to enable the ion current to be extracted from the ionization volume by the extraction system. The invention features a broad beam electron gun constructed, sized and arranged with respect to the ionization chamber to direct an aligned beam of primary electrons through the ionization chamber to a beam dump maintained at a substantial positive voltage relative to the emitter voltage of the electron beam gun. Preferably the beam dump is thermally isolated from the ionization chamber or separately cooled. The axis of the beam path of the primary electrons extends in a direction generally adjacent to the aperture, the electron beam having a dimension in the direction corresponding to the direction of the width of the extraction aperture that is about the same as or larger than the width of the aperture, a vaporizer arranged to introduce e.g. decaborane vapor to the ionization volume, and a control system enables control of the energy of the primary electrons so that individual vapor molecules can be ionized principally by collisions with primary electrons from the electron gun. In preferred embodiments the electron gun is mounted on a support that is thermally isolated from the walls of the ionization chamber. According to another aspect of the invention, an ion source capable of providing ions of decaborane in commercial ion current levels to the ion extraction system of an ion implanter is provided, the ion source comprising an ionization chamber defined by walls enclosing an ionization volume, there being an ion extraction aperture in a side wall of the ionization chamber, arranged to enable the ion current to be extracted from the ionization volume by an extraction system, an electron gun mounted on a support that is outside of and thermally isolated from the walls of the ionization chamber, and constructed, sized and arranged with respect to the ionization chamber to direct a broad beam of primary electrons through the ionization chamber to a beam dump maintained at a substantial positive voltage relative to the emitter voltage of the electron beam gun, the beam dump being located outside of, and thermally isolated from, the ionization chamber, the beam path of the primary electrons extending in a direction adjacent to the ion extraction aperture, a passage arranged to introduce vapor or gas of a selected material to the ionization volume, and a control system enabling control of the energy of the primary electrons so that the material can be ionized. According to another aspect of the invention, an ion source capable of providing ions in commercial ion current levels to the ion extraction system of an ion implanter is provided, the ion source comprising an ionization chamber defined by walls enclosing an ionization volume, there being an extraction aperture in a side wall of the ionization chamber that is arranged to enable the ion current to be extracted from the ionization volume by the extraction system, an electron gun mounted on a support that is outside of and thermally isolated from the walls of the ionization chamber, and constructed, sized and arranged with respect to the ionization chamber to direct a broad beam of primary electrons through the ionization chamber to a beam dump maintained at a substantial positive voltage relative to the emitter voltage of the electron beam gun, the electron beam gun comprising a heated electron emitting surface of predetermined size followed by electron optical elements that enlarge the beam in the ionization chamber relative to the size of the emitting surface of the electron gun, the beam path of the primary electrons extending in a direction adjacent to the ion extraction aperture, a passage arranged to introduce vapor or gas of a selected material to the ionization volume, and a control system enabling control of the energy of the primary electrons so that the material can be ionized. Preferred embodiments of these and other aspects of the invention have one or more of the following features: A vaporizer is incorporated into the ion source assembly in close proximity to the ionization chamber and communicating with it through a high conductance, preferably along a line of sight path, and is constructed to be controllable over part or all of the range of 20° C. to 200° C. The beam dump has an electron-receiving surface larger than the cross-section of the electron beam entering the ionization chamber. The electron gun produces a generally collimated beam, in many instances, preferably the electron gun being generally collimated while transiting the ionization chamber. The beam dump is mounted on a dynamically cooled support, preferably a water-cooled support. The electron gun is mounted on a dynamically cooled support, preferably, a water-cooled support. The electron gun cathode is disposed in a position remote from the ionization chamber. The volume occupied by the electron gun cathode is evacuated by a dedicated vacuum pump. The ion source electron gun includes a cathode and variable electron optics that shape the flow of electrons into a beam of selected parameters, including a general dispersion of the electrons, and a profile matched to the extraction aperture, preferably in many cases the electrons being in a collimated beam within the ionization chamber. The electron gun comprises a high transmission electron extraction stage capable of extracting at least the majority of electrons from an emitter of the gun, the extraction stage followed by a collimator and further electron optic elements, in preferred embodiments the further electron optics comprising an electron zoom lens or electron optics constructed to have the capability to vary the energy and at least one magnification parameter of the electron beam, preferably both linear and angular magnification of the beam and in preferred embodiments the electron optics comprising a five or more element zoom lens. The ion source is constructed, sized and arranged to be retrofit into a pre-existing ion implanter, into the general space occupied by the original ion source for which the implanter was designed. The ion source is constructed and arranged to cause the electron beam to have a profile matched to the opening of the ion extraction aperture, preferably the cross-section being generally rectangular. The electron beam gun of the ion source is an elongated electron gun, in certain embodiments the length of the gun being longer than the length of the ionization path length in the ionization chamber, preferably, e.g. for retrofit installations, the principal direction of the elongated electron gun being arranged generally parallel to the direction in which the ion beam is extracted from the ionization chamber, and an electron mirror is arranged to divert the electron beam to a transverse direction to pass through the ionization volume. In this and other embodiments, preferably the cathode of the elongated electron beam gun is a uniform emitting surface sized smaller than the maximum cross-section of the electron beam passing through the ionization chamber, and the electron optics include optics arranged to expand the electron beam before it enters the ionization chamber. In various embodiments some of the optics precede the mirror or are downstream of the mirror, and the optics are constructed to vary angular as well as linear magnification. Preferably these optics comprise a zoom control to enable variation of the electron energy of the beam. The control system includes a circuit for measuring the current and the intensity of the beam dump. The ion source electron beam gun is constructed to operate with a voltage drop relative to the walls of the ionization chamber between about 20 and 300 or 500 electron volts; preferably, to ionize decaborane, the voltage drop being between 20 and 150 electron volts, higher voltages being useful for providing double charges on selected implant species or for providing ionizing conditions for other feed materials. For use with a previously existing ion implanter designed for use with a Bernas arc discharge source having a directly or indirectly heated cathode; the control system includes an operator control screen corresponding to the screen used for the Bernas source, and a translator effectively translates arc current control signals to control signals for the electron gun. The ionization chamber is in thermal continuity with the vaporizer, or with a temperature control device. The vaporizer for decaborane includes a temperature control system, and the ionization chamber is in thermal continuity with the vaporizer, preferably the ionization chamber is defined within a conductive block defining a heat sink that is in thermal continuity with the vaporizer, preferably, the conductive block being in thermal continuity with the vaporizer via one or more conductive gaskets, including a gasket at which the vaporizer may be separated from the remainder of the assembly. The ionization chamber is defined by a removable block disposed in heat transfer relationship to a temperature controlled mounting block, preferably the removable block comprised of graphite, silicon carbide or aluminum. The ion source includes a mounting flange for joining the ion source to the housing of an ion implanter, the ionization chamber being located on the inside of the mounting flange and the vaporizer being removably mounted to the exterior of the mounting flange via at least one isolation valve which is separable from the mounting flange with the vaporizer, enabling the vaporizer charge volume to be isolated by the valve in closed position during handling, preferably there being two isolation valves in series, one unified with and transportable with a removed vaporizer unit, and one constructed to remain with and isolate the remainder of the ion source from the atmosphere. In certain preferred embodiments, two such vaporizers are provided, enabling one to be absent, while being charged or serviced, while the other operates, or enabling two different materials to be vaporized without maintenance of the ion source, or enabling additional quantities of the same materials to be present to enable a protracted implant run. Opposite walls of the ionization chamber corresponding respectively to the electron beam gun and the beam dump have ports through which electrons pass enroute from the electron beam gun to the beam dump, the spaces in the vicinity of the ports being surrounded by housing and communicating with a vacuum system. The ion source includes a gas inlet via into which compounds such as arsine, phosphene, germane and silane gas can be introduced to the ionization chamber for ionization. The extraction aperture of the ionization chamber, for e.g. high current machines, is about 50 mm or more in length and at least about 3.5 mm in width, and the transverse cross sectional area of the electron beam is at least about 30 square mm, preferably, e.g. for decaborane in high current machines, the cross-sectional area of the beam being at least about 60 square mm. For a medium current ion implanter preferably the extraction aperture is at least 15 mm in length and at least about 1.5 mm in width, and the transverse cross sectional area of the electron beam is at least about 15 square millimeters. In many medium current implanters, the extraction aperture can be sized 20 mm long by 2 mm wide, in which case the cross-sectional area of the electron beam can be reduced to a minimum of about 20 square mm. An ion implantation system is provided comprising an ion implanter designed for a first ion source occupying a general design volume, and a second ion source of any of the novel types described above is operatively installed in that volume, preferably the electron gun being of elongated form, having its principal direction arranged parallel to the direction the ion beam is extracted from the ionization chamber, and an electron mirror is arranged to divert the electron beam to a transverse direction to pass through the ionization volume. In this and other embodiments of an ion implantation system, preferably the cathode is sized smaller than the maximum cross-section of the electron beam passing through the ionization chamber, and the electron optics include optics arranged to expand the electron beam before it enters the ionization chamber, preferably these optics being associated with a zoom control to enable controlled variation of the electron energy. The invention also features methods of employing apparatus having the various features described to ionize decaborane, the mentioned hydrides and other temperature-sensitive materials including indium-, antimony-, and dimer-containing compounds. The methods include using the various methods of control that are described in the preceding description and in the following text. In particular, the invention includes the methods described of generating the electron beam, accelerating and collimating the beam, controlling its transverse profile and its energy, and causing it to transit the ionization chamber to create the desired ions while keeping the ionization chamber cool. It also includes the methods of vaporizing the solid materials and cooling the ionization chamber with the vaporizer heat control system as well as controlling the vapor production of the vaporizer by pressure control or by a dual temperature and pressure control that is for instance capable of adjusting for the decreasing volume of the feed material as operation proceeds. Particular aspects of the invention feature methods of providing ions during ion implantation comprising introducing material comprising a gas or heated vapor to a chamber enclosing an ionization volume, the chamber having an extraction aperture, and passing through the ionization volume adjacent the aperture a broad beam of electrons. According to one aspect of the invention, the broad beam is aligned with a beam dump that is thermally isolated from the chamber, the energy of the electrons being selected to ionize the material. According to another aspect, the energy and magnification of the electron beam are controlled with electron zoom optics to ionize the material. According to another aspect, the beam is formed and the energy of the electrons is controlled by successively accelerating and decelerating the electrons. In preferred embodiments of these aspects the broad electron beam is emitted from a heated emitter surface that is remote from and thermally isolated from the ionization chamber; electrons from an emitter surface are accelerated, collimated and passed through beam-expanding optics before passing through the ionization chamber, and, for vaporizing decaborane, the method includes introducing the decaborane vapors to the ionization chamber, and controlling the broad electron beam parameters to ionize the decaborane and produce a decaborane current, or the method includes introducing to the ionization chamber a hydride of a desired species, and ionizing the hydride, in preferred embodiments the hydride being arsine or phosphene or germane or silane or diborane. In other preferred methods, an indium-containing compound is employed including introducing the indium compound vapors to the ionization chamber, and controlling the broad electron beam parameters to ionize the indium compound and produce an indium ion current, preferably the compound being trimethyl indium. In still other preferred methods, a compound containing antimony is employed including introducing the antimony compound vapors to the ionization chamber, and controlling the broad electron beam parameters to ionize the antimony compound and produce an antimony ion current, preferably the compound being antimony oxide (Sb2O5). Other dimer-containing compounds described below are also useful, both for producing dimer ions and monomer ions. In the various methods preferably a beam dump is employed to receive the electron beam after it transits the ionization volume, including maintaining the beam dump thermally isolated from the chamber and at a voltage potential at least as high as that of the chamber. In some instances a magnetic field is applied to constrain the electron beam, e.g. to counteract space-charge effects. In some instances, for certain compounds, preferably the process described is converted to a reflex ionization mode by changing the potential of the beam dump to a substantially lower potential than the walls of the ionization chamber to act as an electron-repelling anticathode, in certain cases the method including applying a magnetic field parallel to the electron beam, or continuing to cool the walls of the ionization chamber while operating in reflex mode. The invention also features the methods of retrofitting the new ion source into the existing fleet of ion implanters, and of controlling the ion source by means of the operator interface of the arc plasma ion source that it replaces. Also, the invention features methods of conducting entire ion implantation processes using the equipment and controls described to form semiconductor devices, in particular shallow source/drains and extensions, and doping of the silicon gates in CMOS fabrication. In addition, the invention features methods and apparatus for dual mode operation, both a broad E-Beam mode with the beam aligned with a beam dump at positive potential and a reflex mode, in which the dump is converted to a repeller (anticathode) with optional use of a confining magnetic field, advantageously both conducted with cooled walls to ionize materials such as hydrides that disassociate with elevated temperatures. In the method employing a broad electron beam directed to a beam dump, in certain cases the invention features applying a magnetic field to constrain the electron beam. According to another aspect of the invention, an ion source is provided having a member whose surface is exposed to contact of a dopant feed material, including gases, vapors or ions thereof, the relationship of the contact being such that condensation or molecular dissociation will occur if the temperature of the surface of the member is not within a desired operational range, the member being disposed in conductive heat transfer relationship with a second member, the temperature of which is actively controlled. The temperature of the second member can be determined by water-cooling the member with de-ionized water of a given temperature. The second member can be associated with a thermoelectric cooling unit associated with a control system that can activate the unit to maintain the temperature of the surface within said operational range. In some cases a heater element is included which is arranged to cooperate with the cooling unit to maintain the second member at a temperature. In certain embodiments the cooling unit has a surface which forms a thermally conductive interface with an opposed surface of the member. In certain preferred embodiments a conductive gas fills gaps at an interface in the conductive path under conditions in which the gas molecules act to transfer heat across the interface by conduction, preferably the conductive gas being fed into channels formed in at least one of the surfaces across which the thermal heat conduction is to occur. The invention also features a control system for the vaporizer which includes an ionization gauge sensitive to a pressure related to a pressure within the ionization chamber. Another aspect of the invention is an ion source which includes an accel-decel electron gun arranged to project a beam of electrons through an ionization chamber to ionize gas or vapors in a region adjacent an extraction aperture. Preferred embodiments of this aspect have one or more of the following features: A magnetic coil is disposed outside of the ionization chamber, the electron gun is mounted concentrically with the coil, such that the emission axis of the electron gun is aligned to emit electrons into the ionization chamber and the coil, when energized, provides a magnetic field which limits space charge expansion of the electron beam as it transits the ionization chamber. The volume occupied by the electron gun cathode is evacuated by a dedicated vacuum pump. A beam dump at a positive voltage is aligned to receive electrons of the beam that transit the ionization chamber. This accel-decel electron gun is disposed outside of an ionization chamber, the electron gun mounted such that the emission axis of the electron gun is aligned to emit electrons into the ionization chamber. The accel-decel gun has an electron zoom lens. The accel-decel gun is comprised of a high-transmission extraction stage followed by a focusing lens having at least two elements followed by a relatively short, strongly-focusing lens which acts to decelerate the electron beam entering the ionization chamber, preferably the short lens being a multi-aperture lens comprising a series of at least two conducting plates each having an aperture, the voltage on the plates being of respectively decreasing values to decelerate the electrons. The beam deceleration stage of the electron gun focuses the beam in the ionization chamber at a point near mid-length of an elongated aperture, past which the electron beam passes. Other aspects and detailed features of the invention will be apparent from the drawings, the following description of preferred embodiments, and from the claims and abstract. GENERAL DESCRIPTION An embodiment of an ion source incorporating various aspects of the invention is composed of i) a vaporizer, ii) a vaporizer valve, iii) a gas feed, iv) an ionization chamber, v) an electron gun, vi) a cooled mounting frame, and vii) an ion exit aperture. Included are means for introducing gaseous feed material into the ionization chamber, means for vaporizing solid feed materials and introducing their vapors into the ionization chamber, means for ionizing the introduced gaseous feed materials within the ionization chamber, and means for extracting the ions thus produced from an ion exit aperture adjacent to the ionization region. In addition, means for accelerating and focusing the exiting ions are provided. The vaporizer, vaporizer valve, gas feed, ionization chamber, electron gun, cooled mounting frame, and ion exit aperture are all integrated into a single assembly in preferred embodiments of the novel ion source. I will describe each of these features. Vaporizer: The vaporizer is suitable for vaporizing solid materials, such as decaborane (B10H14) and TMI (trimethyl indium), which have relatively high vapor pressures at room temperature, and thus vaporize at temperatures below 100° C. The temperature range between room temperature and 100° C. is easily accommodated by embodiments in which the vaporizer is directly associated with a water heat transfer medium, while other preferred arrangements accommodate novel material which produce significant vapor pressures in the range up to 200° C. For example, solid decaborane has a vapor pressure of about 1 Torr at 20° C. Most other implant species currently of interest in the ion implantation of semiconductors, such as As, P, Sb, B, C, Ar, N, Si, and Ge are available in gaseous forms. However, B10 and In are not, but can be presented in vapors from solid decaborane and TMI. The vaporizer of an embodiment of the invention is a machined aluminum block in which resides a sealed crucible containing the solid material to be vaporized, entirely surrounded by a closed-circuit water bath, which is itself enclosed by the aluminum block. The bath is held at a well-defined temperature by a closed-loop temperature control system linked to the vaporizer. The closed-loop temperature control system incorporates a PID (Proportional Integral Differential) controller. The PID controller accepts a user-programmable temperature setpoint, and activates a resistive heater (which is mounted to a heater plate in contact with the water bath) to reach and maintain it's setpoint temperature through a thermocouple readback circuit which compares the setpoint and readback values to determine the proper value of current to pass through the resistive heater. To ensure good temperature stability, a water-cooled heat exchanger coil is immersed in the water bath to continually remove heat from the bath, which reduces the settling time of the temperature control system. The temperature difference between the physically separate heater plate and heat exchanger coil provides flow mixing of the water within the bath through the generation of convective currents. As an added mixing aid, a rotating magnetic mixer paddle can be incorporated into the water bath. Such a temperature control system is stable from 20° C. to 100° C. The flow of gas from the vaporizer to the ionization chamber is determined by the vaporizer temperature, such that at higher temperatures, higher flow rates are achieved. The flow of gas from a vaporizer to the ionization chamber is determined by the vaporizer temperature, such that at higher temperatures, higher flow rates are achieved. According to preferred embodiments of the invention, the vaporizer communicates with the ionization chamber via a relatively high-conductance path between the crucible and the ionization chamber. This is preferably achieved by incorporating a relatively short, large-diameter, line-of-sight conduit between the two components. High-conductance gate valves (large diameter gates with a thin dimensioned housing) are used in the flow path between the vaporizer and source body, so as not to limit this conductance. By providing a high conductance for the transport of vapor to the ionization chamber, the pressure within the vaporizer and the temperature excursion required are lower than in prior vaporizers. In one embodiment according to the invention a relatively low conductance supply path is achieved employing a 5 mm diameter, 20 cm long conduit, providing a conductance of about 7×10−2 L/s between crucible and ionization chamber. This would require a pressure within the vaporizer of about 2 Torr to establish an ionization chamber pressure of about 4.5 mTorr. Another embodiment employs an 8 mm diameter conduit of the same length, providing a conductance of about 3×10−1 L/s, allowing a pressure within the vaporizer of 0.5 Torr to achieve the same flow rate of material, and hence the same pressure of 4.5 mTorr within the ionization chamber. The static vapor pressure of a material at a given temperature and the dynamic pressure in the vaporizer crucible during the evolution and transport of vapor out of the crucible during operation are not the same. In general, the steady-state dynamic pressure is lower than the static vapor pressure, the extent depending on the distribution of source material within the vaporizer crucible, in addition to other details of construction. According to the invention, the conductances are made large to accommodate this effect. In addition, in certain preferred embodiments, the added openness of the ionization chamber to the vacuum environment of the source housing due to electron entrance and exit ports into the ionization chamber requires about twice the flow of gaseous material as a conventional Bernas-style source. Generally according to the invention, it is preferred that the conductance be in the range of about 3×10−2 to 3×10−1 L/s, preferably the length of the conduit being no less than 30 cm while its diameter is no less than about 5 mm, the preferred diameter range being between 5 and 10 mm. Within these limits it is possible to operate at much lower temperatures than conventional vaporizers, no large addition of temperature being required to elevate the pressure to drive the flow to the ionization chamber. Thus the temperature-sensitive materials are protected and a broad range of materials are enabled to be vaporized within a relatively small temperature range. In several of the embodiments of the vaporizer presented, the construction of the vaporizer, following these guidelines, allows operation at temperatures between 20° C. and 100° C. or 200° C. Given the high conductance of the vaporizer, and such temperature ranges, I have realized that the wide range of solid source materials that can be accommodated include some materials which have not previously been used in ion implantation due to their relatively low melting point. (It generally being preferred to produce vapors from material in solid form). An additional advantage of enabling use of only a relatively low pressure of vaporized gas within the crucible is that less material can be required to establish the desired mass flow of gas than in prior designs. In another embodiment a different vaporizer PID temperature controller is employed. In order to establish a repeatable and stable flow, the vaporizer PID temperature controller receives the output of an ionization-type pressure gauge which is typically located in the source housing of commercial ion implanters to monitor the sub-atmospheric pressure in the source housing. Since the pressure gauge output is proportional to the gas flow into the ion source, its output can be employed as the controlling input to the PID temperature controller. The PID temperature controller can subsequently raise or diminish the vaporizer temperature, to increase or decrease gas flow into the source, until the desired gauge pressure is attained. Thus, two useful operating modes of a PID controller are defined: temperature-based, and pressure-based. In another embodiment, these two approaches are combined such that short-term stability of the flow rate is accomplished by temperature programming alone, while long-term stability of the flow rate is accomplished by adjusting the vaporizer temperature to meet a pressure setpoint. The advantage of such a combined approach is that, as the solid material in the vaporizer crucible is consumed, the vaporizer temperature can be increased to compensate for the smaller flow rates realized by the reduced surface area of the material presented to the vaporizer. In another preferred embodiment of the vaporizer, a fluid heat transfer medium is not used. Rather than a water bath, the crucible is integral with the machined body of the vaporizer, and heating and cooling elements are embedded into the aluminum wall of the vaporizer. The heating element is a resistive or ohmic heater, and the cooling element is a thermoelectric (TE) cooler. The vaporizer is also encased in thermal insulation to prevent heat loss to the ambient, since the desired vaporizer temperature is typically above room temperature. In this embodiment, the heating/cooling elements directly determine the temperature of the walls of the vaporizer, and hence the temperature of the material within the crucible, since the material is in direct contact with the walls of the vaporizer which is e.g. machined of a single piece of aluminum. The same PID temperature controller techniques can be used as in the previously described embodiment, enabling the vaporizer to reach a temperature in excess of 100° C., preferably up to about 200° C. In another embodiment, the vaporizer consists of two mating, but separate components: a vaporizer housing and a crucible. The crucible is inserted into the housing with a close mechanical fit. The surface of the vaporizer housing which makes contact with the crucible contains a pattern of rectangular grooves, into which subatmospheric pressurized conductive gas is introduced. The pressurized gas provides sufficient thermal conductivity between the crucible and the temperature-controlled housing to control the temperature of the crucible surface in contact with decaborane or other solid feed material to be vaporized. This embodiment allows the crucible to be easily replaced during service of the vaporizer. The same PID temperature controller techniques can be used as in the previously described embodiment. In some preferred embodiments, the vaporizer, while still close to the ionization chamber, communicating with it through a high conductance path, is physically located outside of, and removably mounted to, the main mounting flange of the ion source and the vaporizer communicates through the main mounting flange to the ionization chamber located within the vacuum system. In some preferred embodiments, two vaporizers, independently detachable from the remainder of the ion source, are provided, enabling one vaporizer to be in use while the other, detached, is being recharged or serviced. Vaporizer valve: In the above described vaporizer embodiments, the vapors leave the vaporizer and enter the adjacent ionization chamber of the ion source through an aperture, which is preferably coupled to a thin, high conductance gate valve with a metal seal or other thermally conductive seal placed between the vaporizer and ionization chamber. The gate valve serves to separate the vaporizer from the ionization chamber, so that no vapor escapes from the vaporizer when the valve is shut, but a short, high-conductance line-of-sight path is established between the ionization chamber and vaporizer when the valve is open, thus allowing the vapors to freely enter the ionization chamber. With the valve in the closed position, the vaporizer with the valve attached may be removed from the ion source without releasing the toxic vaporizer material contained in the crucible. The ion source may then be sealed by installing a blank flange in the position previously occupied by the vaporizer valve. In another embodiment, two isolation valves are provided in series, one associated with the removable vaporizer and one associated with all of the other components of the ion source, with the disconnect interface being located between the two valves. Thus both parts of the system can be isolated from the atmosphere while the parts are detached from one another. One of the mating valves (preferably, the valve isolating the ion source body) has a small, valved roughing port integrated internal to the valve body, which enables the air trapped in the dead volume between them to be evacuated by a roughing pump after the two valves are mated in a closed position. If the source housing of the implanter is under vacuum, the vaporizer can be installed with its valve in a closed state after being refilled. It is mated to the closed valve mounted to the ion source in the implanter. The vaporizer valve can then be opened and the vaporizer volume pumped out through the roughing port (along with the gas trapped in the dead volume between the valves). Then the ion source valve can be opened, without requiring venting of the source housing. This capability greatly reduces the implanter down time required for servicing of the vaporizer. In another system, two such vaporizers, each with two isolation valves in series, as described, are provided in parallel, suitable to vaporize different starting materials, or to be used alternatively, so that one may be serviced and recharged while the other is functioning. Gas feed: In order to operate with gaseous feed materials, ion implanters typically use gas bottles which are coupled to a gas distribution system. The gases are fed to the ion source via metal gas feed lines which directly couple to the ion source through a sealed VCR or VCO fitting. In order to utilize these gases, embodiments of the ion source of the present invention likewise have a gas fitting which couples to the interior of the ionization chamber and connects to a gas distribution system. Ionization chamber: The ionization chamber defines the region to which the neutral gas or vapor fed to the source is ionized by electron impact. In certain preferred embodiments, the ionization chamber is in intimate thermal and mechanical contact with the high conductance vaporizer valve or valves through thermally conductive gaskets, which are likewise in intimate thermal contact with the vaporizer through thermally conductive gaskets. This provides temperature control of the ionization chamber through thermal contact with the vaporizer, to avoid heat generated in the ionization chamber from elevating the temperature of the walls of the chamber to temperatures which can cause decaborane or other low-temperature vaporized materials or gases to break down and dissociate. In other embodiments, the ionization chamber, as a removable component, (advantageously, in certain instances, a regularly replaced consumable component) is maintained in good heat transfer relationship with a temperature-controlled body, such as a temperature controlled solid metal heat sink having a conventional water cooling medium or being cooled by one or more thermoelectric coolers. The ionization chamber in preferred embodiments suitable for retrofit installation is sized and constructed to provide an ionization volume, extraction features, and ion optical properties compatible with the properties for which the target implanter to be retrofitted was designed. In preferred embodiments, the ionization chamber is rectangular, made of a single piece of machined aluminum, molybdenum, graphite, silicon carbide or other suitable thermally conductive material. Because contact of the ionization chamber with a fluid transfer medium is avoided in designs presented here, in certain instances the ionization chamber and extraction aperture are uniquely formed of low cost graphite, which is easily machined, or of silicon carbide, neither of which creates risk of transition metals contamination of the implant. Likewise for the low temperature operations (below its melting point) an aluminum construction may advantageously be employed. A disposable and replaceable ionization chamber of machined graphite or of silicon carbide is a particular feature of the invention. The ionization chamber in certain preferred embodiments is approximately 7.5 cm tall by 5 cm wide by 5 cm deep, approximating the size and shape of commercially accepted Bernas arc discharge ionization chambers. The chamber wall thickness is approximately 1 cm. Thus, the ionization chamber has the appearance of a hollow, rectangular five-sided box. The sixth side is occupied by the exit aperture. The aperture can be elongated as are the extraction apertures of Bernas arc discharge ion sources, and located in appropriate position in relation to the ion extraction optics. The flow rate of the gas fed into the ionization chamber is controlled to be sufficient to maintain proper feed gas pressure within the ionization chamber. For most materials, including decaborane, a pressure between 0.5 mTorr and 5 mTorr in the ionization chamber will yield good ionization efficiency for the system being described. The pressure in the source housing is dependent upon the pressure in the ionization chamber. With the ionization chamber pressure at 0.5 mTorr or 5 mTorr, the ion gauge mounted in the source housing, typically used in commercial ion implanters to monitor source pressure, will read about 1×10−5 Torr and 1×10−4 Torr, respectively. The flow rate from the vaporizer or gas feed into the ionization chamber required to sustain this pressure is between about 1 sccm and 10 sccm (standard cubic centimeters per minute). Electron gun: For ionizing the gases within the ionization chamber, electrons of controlled energy and generally uniform distribution are introduced into the ionization chamber by a broad, generally collimated beam electron gun as shown in the illustrative figures described below. In one embodiment of the invention, a high-current electron gun is mounted adjacent one end of the ionization chamber, external to that chamber, such that a directed stream of primary energetic electrons is injected through an open port into the ionization chamber along the long axis of the rectangular chamber, in a direction parallel to and adjacent the elongated ion extraction aperture. In preferred embodiments of the invention, the cathode of the electron gun is held at an electric potential below the potential of the ionization chamber by a voltage equal to the desired electron energy for ionization of the molecules by the primary electrons. Two ports, respectively in opposite walls of the ionization chamber are provided to pass the electron beam, one port for entrance of the beam as mentioned above, and the second port for exit of the beam from the ionization chamber. After the electron beam exits the ionization chamber, it is intercepted by a beam dump located just outside of the ionization chamber the beam dump being aligned with the electron entry point, and preferably maintained at a potential somewhat more positive than that of the ionization chamber. The electron beam is of an energy and current that can be controllably varied over respective ranges to accommodate the specific ionization needs of the various feed materials introduced into the ionization chamber, and the specific ion currents required by the ion implant processes of the end-user. In particular embodiments, the electron gun is constructed to be capable of providing an electron beam energy programmable between 20 eV and 500 eV. The lowest beam energies in this energy range accommodate selective ionization of a gas or vapor below certain ionization threshold energies, to limit the kinds of end-product ions produced from the neutral gas species. An example is the production of B10Hx+ ions without significant production of B9Hx+, B8Hx+, or other lower-order boranes frequently contained in the decaborane cracking pattern when higher electron impact energies are used. The higher beam energies in the energy range of the electron gun are provided to accommodate the formation of multiply-charged ions, for example, As++ from AsH3 feed gas. For the majority of ion production from the various feed gases used in semiconductor manufacturing, including the production of B10Hx+ from decaborane, an electron beam energy between 50 eV and 150 eV can yield good results. In preferred embodiments, the electron gun is so constructed that the electron beam current can be selected over a range of injected electron beam currents between 0.1 mA and 500 mA, in order to determine the ion current extracted from the ion source in accordance with the implant demand. Control of electron current is accomplished by a closed-loop electron gun controller which adjusts the electron emitter temperature and the electron gun extraction potential to maintain the desired electron current setpoint. The electron emitter, or cathode, emits electrons by thermionic emission, and so operates at elevated temperatures. The cathode may be directly heated (by passing an electric current through the cathode material), or indirectly heated. Cathode heating by electron bombardment from a hot filament held behind the cathode is an indirect heating technique well-practiced in the art. The cathode may be made of tungsten, tantalum, lanthanum hexaboride (LaB6), or other refractory conductive material. It is realized that LaB6 offers a particular advantage, in that it emits copious currents of electrons at lower temperatures than tungsten or tantalum. As discussed further below, the preferred separate mounting of the electron beam gun, thermally isolated from the ionization chamber, is an advantageous factor in keeping the ionization chamber cool. Electron beam guns having cathodes mounted close to the ionization chamber on a cooled support, which discharge directly into the chamber, are shown in the first two embodiments described below. Further advantages are obtained in certain embodiments by use of an elongated electron gun design, i.e. typically longer that the length of the ionization chamber transitted by the beam. This enables the heated cathode of the gun to be located quite far from the ionization chamber, completely thermally isolated from it, and enables use of a small highly efficient cathode by combination with telescopic electron optics to achieve the desired broad electron beam and desired electron density across the beam cross section (profile). A zoom lens can advantageously enable variation of the cross-section of the electron beam that transits the ionization chamber to match the size of the selected aperture and beam current. In an advantageous, space-efficient design, the elongated electron gun is mounted parallel to the direction of extraction of the ion beam, with the cathode located near or even outside, beyond the mounting flange of the ion source, and associated at its other end with an electron beam mirror that deflects the beam to transit the ionization chamber. In new implanter designs in which there are not as many predetermined space constraints, the described elongated electron beam gun, with relatively small emitter surface, and associated zoom lens can be arranged in line with the direction of transit of the electron through the ionization chamber, no diverting mirror being employed. In a high current design an acceleration-deceleration system aligned with the direction of transit through the ionization chamber is advantageous in a number of respects, especially when employing an accel-decel system for maximizing the electron flow through the ionization chamber. The electron beam, however produced, has a significant cross-sectional area, i.e. it is a broad generally collimated beam as it transits the ionization chamber, to the beam dump with which it is aligned. In preferred embodiments, the electron beam within the ionization chamber has a generally rectangular cross section, e.g. in one embodiment approximately 13 mm×6 mm as injected into the ionization chamber, to match with a relatively wide extraction aperture of a high current machine, or the rectangular cross section is e.g. of a square cross-section profile for use with a narrower ion extraction aperture. In the case of direct injection, the shape of the injected electron beam can be determined by the shape of the electron optics, e.g. the grid and anode apertures of an electron gun, which, for example, may both be approximately 13 mm×6 mm, and also by the shape of the cathode or electron emitter, which, for the first example given, is somewhat larger than the grid and anode apertures, approximately 15 mm×9 mm. The advantage of generating a generally rectangular electron beam profile is to match the conventionally desired ion beam profile as extracted from the ion source, which is also rectangular. The rectangular exit aperture from which the ion beam is extracted is approximately 50 mm tall by 3.5 mm wide in many high-current implanters; in such cases the electron beam (and thus the ions produced by electron impact) can present a profile to the exit aperture within the ionization chamber of approximately 64 mm×13 mm. If the end-user wishes, an enlarged exit aperture may be employed to obtain higher extracted currents. As mentioned above, preferably in the walls of the ionization chamber, there are both an electron entrance port and an aligned electron exit port for the electron beam, which departs from the conventionally employed Bernas ion source. In Bernas ion sources, energetic electrons produced by an emitter, located typically internal to the ionization chamber, strike the walls of the chamber to form the basis of an “arc discharge”. This provides a substantial heat load which elevates the temperature of the ionization chamber walls. In the present invention, the ionizing electrons (i.e the energetic or “primary” electrons) pass through the ionization chamber to the defined beam dump, substantially without intercepting the general chamber walls. “Secondary” electrons, i.e. low-energy electrons produced by ionization of the feed gas, still can reach the general walls of the ionization chamber but since these are low energy electrons, they do not provide significant heat load to the walls. The feature of through-transit of the primary electrons allows the ionization chamber to be conductively cooled, e.g. by the vaporizer, or by a cooled block against which the ionization chamber is mounted in substantial thermal contact, without providing a large heat load on the temperature controller of the vaporizer or block. To avoid the heat generated by the electron gun and the energetic electron beam, the electron gun and the electron beam dump are mounted in thermally isolated fashion, preferably either or both being mounted on respective water-cooled parts of a cooled mounting frame. This frame is dynamically cooled, e.g. by high-resistivity, de-ionized water commonly available in commercial ion implanters. Cooled mounting frame and Beam Dump: The cooled mounting frame is e.g. a water-cooled sheet metal assembly on which the electron gun and the electron beam dump may be mounted. The frame consists of two separate mechanical parts which allow the electron gun and the beam dump to be independently biased. By mounting these two components to this frame, a heat load to the ionization chamber can be substantially avoided. The frame provides a mechanical framework for the thus-mounted components, and in addition the frame and the mounted components can be held at an electric potential different from the potential of the ionization chamber and vaporizer by mounting to the ion source assembly on electrically insulating standoffs. In embodiments discussed below, the beam dump is discretely defined and isolated, preferably being removed from direct contact with the ionization chamber, with the electron beam passing through an exit port in the ionization chamber prior to being intercepted by the beam dump. The beam dump can readily be maintained at a potential more positive than the walls of the chamber to retain any secondary electrons released upon impact of primary electrons up on the beam dump. Also, the beam dump current can be detected for use in the control system as well as for diagnostics. Also, in a multi-mode ion source, by being electrically isolated, the voltage on the dump structure can be selectively changed to negative to serve an electron-repeller (anticathode) function, as described below. In another construction, the distinctly defined beam dump though can be in physical contact with the exit port in such a way that thermal conduction between the cooled beam dump and the exit port is poor e.g., by point contact of discrete elements. Electrical insulation, which has thermal insulation properties as well, can be provided to enable a voltage differential to be maintained while preventing heating of the general walls of the ionization chamber. One advantage of this embodiment is a reduced conduction of the source gas out of the ionization chamber, reducing gas usage. The extraction of ions from the ionization chamber is facilitated by an asymmetric relationship of the electron beam axis relative to the central chamber axis, locating the site of ionization closer to the extraction aperture. By maintaining a voltage on the aperture plate through which the ions are extracted that is lower than that of the other chamber walls, the ions are drawn toward the extraction path. In use of the ion source in a mode different from that used for decaborane as described above, e.g. using BF3 feed gas, the electron beam dump may be biased to a negative potential relative to the ionization chamber, e.g. to a voltage approximating that of the cathode potential, in a “reflex geometry” whereby the primary electrons emitted by the electron gun are reflected back into the ionization chamber and to the cathode, and back again repeatedly, i.e. instead of serving as a beam dump, in this mode the dump structure serves as a “repeller”, or anticathode. An axial magnetic field may also be established along the direction of the electron beam by a pair of magnet coils external to the ion source, to provide confinement of the primary electron beam as it is reflected back and forth between the cathode and beam dump. This feature also provides some confinement for the ions, which may increase the efficiency of creating certain desired ion products, for example B+ from BF3 feed gas. Such a reflex mode of operation is known per se by those practiced in the art, but is achieved here in a unique multi-mode ion source design capable of efficiently producing e.g. decaborane ions. A novel multimode ion source includes an electron gun for the purposes as described, disposed coaxially within a magnet coil that is associated with the source housing and ionization chamber contained within. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagrammatic view of a prior art ion implanter; FIG. 2 is a diagrammatic cross-sectional view of a Bernas arc discharge ion source, illustrative of the ion source for which the implanter of FIG. 1 was designed; FIG. 3 is a longitudinal cross-sectional view of an embodiment of the ion source of the present invention with associated vaporizer; FIG. 3A is a cross-sectional view, similar to a part of FIG. 3, showing another embodiment of a vaporizer; FIG. 3B illustrates the removable feature of the vaporizer of FIG. 3A, using a conventional mounting flange while FIG. 3C illustrates detaching the vaporizer and valve from the ion source; FIG. 3D illustrates a two-valve embodiment in which separation of the vaporizer from the ion source can occur between the two valves; FIG. 3E illustrates a dual vaporizer embodiment; FIG. 3F shows another embodiment of a vaporizer similar to FIG. 3A, but with a separate crucible and with gas-mediated conduction between vaporizer housing and crucible, and between a heat exchanger and the housing. FIG. 4 is a side cross-sectional view taken on line 4-4 of FIG. 3 while FIG. 4A is a top view taken on line 4A-4A of FIG. 4; FIGS. 4B and 4C are views similar to that of FIG. 4, of other arrangements of the discretely defined electric beam dump; FIGS. 4D and 4E, side and top views similar respectively to FIGS. 4 and 4A, show a conductively cooled ionization chamber assembly having a disposable inner ionization chamber. FIG. 4F is a three dimensional representation of a broad, collimated electron beam and its relation to the ion extraction aperture of the embodiment of FIGS. 3 and 4; FIG. 5 is a view similar to FIG. 4F of the relationship of a broad electron beam and ion extraction aperture of narrower dimension; FIG. 6 is a front view of the aperture plate of the ion source of FIG. 3; FIG. 7 is an illustration of an indirectly heated cathode arrangement; FIG. 8 illustrates the ion source of FIGS. 3-6 installed in a retrofit volume of a pre-existing ion implanter while FIG. 8A illustrates, on a smaller scale, the entire implanter of FIG. 8; FIG. 9, similar to FIG. 8, shows an ion source employing an elongated right angle electron gun and an angled mirror while FIG. 9A illustrates the entire implanter into which the embodiment of FIG. 9 is retrofit; FIG. 9B is a view similar to a portion of FIG. 9 on an enlarged scale, illustrating a demountable ionizing chamber directly mounted upon a water-cooled block; FIG. 10 is a side view on an enlarged scale of a preferred embodiment of the elongated electron gun of FIG. 9; FIG. 11 is an enlarged diagram of the extraction stage of the gun of FIG. 10; FIG. 12 illustrates the trajectories of electrons through the extraction stage of FIG. 11; FIG. 13 is a diagrammatic view of a 5-element zoom lens; FIGS. 13A through 13D illustrate various operating modes of the lens system of FIG. 13; FIG. 14 is a plot of the zoom voltage line; FIG. 15 is a diagram of the operator interface of a conventional Bernas arc discharge ion source while FIG. 15A is a similar view of a Bernas source with indirectly heated cathode; FIG. 16 is a view of a Bernas operator interface combined with a novel configurable universal controller that controls a broad E-Beam ion source according to the invention; FIG. 16A is a view similar to FIG. 16 of the control system for an elongated E-Beam embodiment of the invention; FIG. 16B is a diagram of a preferred embodiment of a temperature control system for the vaporizer of FIGS. 3 and 3A; FIG. 17 is a diagrammatic illustration of a semiconductor device, illustrating standard CMOS ion implantation applications. FIG. 18 is a diagram of a high-current electron gun incorporated into a preferred embodiment of the ion source, where the optical axis of the electron gun is parallel to the long axis of the ionization chamber, showing the approximate scale and operating voltages of the different elements; FIG. 18A shows the electron optics of the ion source of FIG. 18, where the focusing properties of a double-aperture lens are illustrated by object and image points, and also the detailed mechanical structure of the ionization chamber and beam dump are illustrated; FIG. 18B illustrates mounting the ion source of FIGS. 18 and 18A into an existing ion implanter, and a special arrangement of the electron gun and magnet coils. FIG. 19 is a top view of an aperture plate that has provisions for receiving a bias voltage relative to the voltage of the remaining walls of an ionization chamber, while FIGS. 19A and 19B, taken on respective lines in FIG. 19, are side views respectively of the inside face of the aperture plate, facing the interior of the ionization chamber and the outside face, directed toward the extraction optics. FIG. 19C is an edge view of an aperture plate illustrating it's mounting to the main body of the ionization chamber by insulating stand offs. FIGS. 20A and 20B an side views of the inside face and outside face of an aperture insert plate of another embodiment while FIG. 20C is a side view of an insulator frame into which the insert plate of FIGS. 20A and 20B may be mounted. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 3 shows in schematic an embodiment of ion source 1. The vaporizer 2 is attached to the vaporizer valve 3 through an annular thermally conductive gasket 4. The vaporizer valve 3 is likewise attached to the mounting flange 7, and the mounting flange 7 is attached to ionization chamber body 5 by further annular thermally conductive gaskets 6 and 6A. This ensures good thermal conduction between the vaporizer, vaporizer valve, and ionization chamber body 5 through intimate contact via thermally conductive elements. The mounting flange 7 attached to the ionization chamber 5, e.g., allows mounting of the ion source 1 to the vacuum housing of an ion implanter, (see FIG. 8) and contains electrical feedthroughs (not shown) to power the ion source, and water-cooling feedthroughs 8, 9 for cooling. In this preferred embodiment, water feedthroughs 8, 9 circulate water through the cooled mounting frame 10 to cool the mounting frame 10 which in turn cools the attached components, the electron beam dump 11 and electron gun 12. The exit aperture plate 13 is mounted to the face of the ionization chamber body 5 by metal screws (not shown). Thermal conduction of the ion exit aperture plate 13 to the ionization chamber body 5 is aided by conductive annular seal 14 of metal or a thermally conductive polymer. When the vaporizer valve 3 is in the open position, vaporized gases from the vaporizer 2 can flow through the vaporizer valve 3 to inlet channel 15 into the open volume of the ionization chamber 16. These gases are ionized by interaction with the electron beam transported from the electron gun 12 to the electron beam dump 11. The ions produced in the open volume can then exit the ion source from the exit aperture 37, where they are collected and transported by the ion optics of the ion implanter. The body of vaporizer 2 is made of machined aluminum, and houses a water bath 17 which surrounds a crucible 18 containing a solid feed material such as decaborane 19. The water bath 17 is heated by a resistive heater plate 20 and cooled by a heat exchanger coil 21 to keep the water bath at the desired temperature. The heat exchanger coil 21 is cooled by de-ionized water provided by water inlet 22 and water outlet 23. The temperature difference between the heating and cooling elements provides convective mixing of the water, and a magnetic paddle stirrer 24 continuously stirs the water bath 17 while the vaporizer is in operation. A thermocouple 25 continually monitors the temperature of the crucible 18 to provide temperature readback for a PID vaporizer temperature controller (not shown). The ionization chamber body 5 is made of aluminum, graphite, silicon carbide, or molybdenum, and operates near the temperature of the vaporizer 2 through thermal conduction. In addition to low-temperature vaporized solids, the ion source can receive gases through gas feed 26, which feeds directly into the open volume of the ionization chamber 16 by an inlet channel 27. Feed gases provided through channel 27 for the ion implantation of semiconductors include AsH3, PH3, SbF5, BF3, CO2, Ar, N2, SiF4, and GeF4, and with important advantages GeH4, SiH4, and B2H6, described below. When the gas feed 26 is used to input feed gases, the vaporizer valve 3 is closed. In the case of a number of these gases, the broad beam electron ionization of the present invention produces a mid-to-low ion current, useful for mid-to-low dose implantations. For higher doses, an embodiment capable of switching mode to a reflex geometry, with magnetic field, can be employed. The vaporizer 2 of FIG. 3, or that of FIG. 3A to be described, can be demounted from the ion source 1 by closing the vaporizer valve 3 and removing the unit at seal 6, (parting line D), compare FIGS. 3B and 3C. This is useful for recharging the solid feed material in the crucible 18, and for maintenance activities. In the embodiment of FIG. 3D, two valves, 3 and 3A are provided in series, valve 3 being permanently associated, as before, with removable vaporizer 28 and valve 3A being permanently associated with mounting flange 7, with the demounting plane D disposed between the two valves. In the embodiment of the ion source shown in FIG. 3A, the vaporizer 28 is of a different design from that of FIG. 3, while the rest of the ion source is the same as in FIG. 3. In vaporizer 28, there is no water bath or water-fed heat exchanger. Instead, the volume occupied by water bath 17 in FIG. 3 is occupied by the machined aluminum body 29 of vaporizer 28. A resistive heater plate 20 is in direct thermal contact with the vaporizer body 29 to conductively heat the body 29, and a thermoelectric (TE) cooler 30 is in direct thermal contact with the vaporizer body 29 to provide conductive cooling. A thermally insulating sleeve 31 surrounds the vaporizer 28 to thermally insulate the vaporizer from ambient temperature. If desired, several heater plates 20 and TE coolers 30 can be distributed within the vaporizer body 29 to provide more conductive heating and cooling power, and also to provide a more spatially uniform temperature to the crucible. This construction permits the vaporizer to operate at temperatures in excess of 100° C., up to about 200° C. FIGS. 3B illustrates an embodiment in which successive mounting flanges of the series of vaporizer 28, isolation valve 3 and the ion source 1, are of increasing size, enabling access to each flange for detachment. Mounting flange 70 enables bolt-on of the assembled ion source to the ion source housing, see e.g. FIG. 8. Mounting Flange 7a enables attachment and detachment of the vaporizer 28 and its associated valve 3 from flange 7 at parting line D, see FIG. 3C. Mounting Flange 7b enables detachment of the valve 3 from the main body of the vaporizer for maintenance or recharging the vaporizer. The embodiment of FIG. 3D has two valves 3 and 3a, valve 3 normally staying attached to the vaporizer and valve 3a normally attached to ion source mounting flange 7. These enable isolation of both the vaporizer 28 and the ion source 1 before demounting the vaporizer at parting line D. The body of mated valve 3a includes roughing passage 90 connected by valve 92 to roughing conduit 91 by which the space between the valves may be evacuated, and, upon opening valve 3, by which the vaporizer may be evacuated prior to opening valve 3a. Thus attachment of vaporizer 28 need not adversely affect the vacuum being maintained in the ion source and beam line. The vent line 93, and associated valve 94 enables relief of vacuum within the vaporizer prior to performing maintenance and as well may be used to evacuate and outgas the vaporizer after recharging, to condition it for use. The embodiment of FIG. 3E illustrates a dual vaporizer construction, having the capabilities previously described. The vapor passage 15 in metal block heat sink 5a bifurcates near mounting flange 7, the branches 15′ leading to respective demountable vaporizers VAP 1 and VAP 2, each having two isolation valves separable at parting line D. As more fully described with respect to FIG. 9B, the ionization chamber body 5b is of discrete construction, demountably mounted in intimate heat transfer relationship to temperature controlled mounting block 5a. Separate coolant passage 66 and 67 telescopically receive so-called squirt tubes which centrally conduct cold, deionized water to the dead end of the passage. The emerging cooled water has its maximum effect at that point, in the outward regions of respectively the mounting block 5a and the cooled frame 10, the water returns through the annular space defined between the exterior of the squirt tube and the passage in which the tube resides. FIG. 3F shows a vaporizer similar to that of FIG. 3A, but instead of a one-piece aluminum construction, the body of the vaporizer has two mating, but separate components: a vaporizer housing 291 and a crucible 181. The crucible is inserted into the housing 291 with a close mechanical fit. The surface of the vaporizer housing which makes contact with the crucible contains a pattern of rectangular grooves, into which pressurized gas (typically at subatmospheric pressure) is introduced through gas inlet 931. The pressurized gas provides sufficient thermal conductivity between the crucible 181 and the temperature-controlled housing 291 to control the temperature of the crucible surface 65 in contact with decaborane or other solid feed material 19 to be vaporized. This embodiment allows the crucible 181 to be easily replaced during service of the vaporizer. Gas is also fed into the volume surrounding heat exchanger 21, to promote thermal conduction between the heat exchanger 21 and the housing 291. The heat exchanger 21 is shown as a water-fed coil, but may alternatively comprise a TE cooler, such as cooler 30 in FIG. 3A. Referring to FIG. 4, in operation of the ion source 1, an electron beam 32 is emitted from the cathode 33 and focused by the electron optics 34 to form a broad, collimated beam, consisting of dispersed electrons (preferably generally uniformly dispersed). The electron beam is wider perpendicular to the ion beam axis than it is along that axis. FIG. 4 illustrates the geometry of the ion source with the exit aperture plate 13 removed; the ion beam axis points out of the plane of the paper, see FIG. 4A. The distribution of ions created by neutral gas interaction with the electron beam corresponds generally to the defined profile of the electron beam. The electron beam passes through a rectangular entrance port 35 in the ionization chamber and interacts with the neutral gas within the open volume 16, defined within the ionization chamber body 5. The beam then passes directly through a rectangular exit port 36 in the ionization chamber and is intercepted by the beam dump 11, which is mounted on the water-cooled mounting frame 10. Beam dump 11 is maintained at a positive potential relative to the electron gun, and preferably slightly positive relative to the walls of the ionization chamber as well. Since the heat load generated by the hot cathode 33 and the heat load generated by impact of the electron beam 32 with the beam dump 11 is substantial, their location outside of the ionization chamber open volume 16 prevents their causing dissociation of the neutral gas molecules and ions. The only heat load from these elements to the ionization chamber is limited to modest radiation, so the ionization chamber can be effectively cooled by thermal conduction to the vaporizer 2 (FIG. 3) or by conduction to a massive mounting block 5a (FIGS. 3E, 9B). Thus, the general walls of the ionization chamber can be reliably maintained at a temperature below the dissociation temperature of the neutral gas molecules and ions. For decaborane, this dissociation temperature is about 350° C. Since the ion exit aperture 37 in plate 13, shown in FIGS. 4B, 5 and 6, is a generally rectangular aperture, the distribution of ions created adjacent to the aperture by the broad, collimated beam of generally uniformly dispersed electrons should be likewise uniform. In the ionization of decaborane and other large molecules, according to this embodiment, an arc plasma is not sustained, but rather the gas is ionized by direct electron-impact ionization by the primary (energetic) electrons, in the absence of containment by any major confining magnetic field. The absence of such magnetic field limits the charge-exchange interactions between the ions and relatively cool secondary electrons as they are not strongly confined as they are in an arc plasma (confined secondary electrons can cause loss of the ions of interest through multiple ionizations). The decaborane ions are generated in the widely distributed electron beam path. This reduces the local ion density relative to other conventional ion sources known in the art. The absence of magnetic field can improve the emittance of the extracted ion beam, particularly at low (e.g., 5 keV) extraction energy. The absence of an arc plasma as in a Bernas source also can improve emittance since there is no plasma potential present in the ionization and extraction region. (I recognize that the presence of an arc plasma potential in conventional plasma-based ion sources introduces a significant random energy component to the ions prior to being extracted, which translates directly into an added angular spread in the extracted ion beam. The maximum angular spread θ due to a plasma potential (p is given by: θ={square root}2 arcsin{φ/E}1/2, where E is the beam energy. For example, for a plasma potential of 5 eV and a beam energy of 5 keV, θ=2.5 deg. In contrast, the random energy of ions produced by direct electron-impact ionization is generally thermal, much less than 1 eV.) FIG. 4A shows a top view of the electron exit port 36 in the open volume 16 of ionization chamber body 5, and its proximity to the ion exit aperture 37 in aperture plate 13. To enable the ions to be removed from the ionization chamber by penetration of an electrostatic extraction field outside of the ion source 1 through the ion exit aperture 37, the electron beam 32 and electron exit port 36 are situated close to the exit aperture plate 13 and its aperture 37. For example, a separation of between 6 mm and 9 mm between the edge of the ionization region and the ion extraction aperture can result in good ion extraction efficiency, the efficiency improving with larger width extraction apertures. Depending upon the particular parameters chosen, the broad, collimated electron beam 32 may not fully retain its rectangular profile due to scattering, and also due to space charge forces within the electron beam 32. The electron exit port 36 is sized appropriately in accordance with such design choices to allow passage of the electron beam without significant interception by the general walls of the ionization chamber body 5. Thus, in certain advantageous instances, port 36 is larger than port 35 so that it is aligned to receive and pass at least most of the residual electron beam. The embodiment of FIG. 4B illustrates a discretely defined beam dump 11′ which is sized and shaped to fit within port 36′ such that its inner, electron receiving surface lies flush with the inner surface of the surrounding end wall of the chamber body 5. Beam dump 11′ is mounted upon and is cooled by cooled frame 10, as before. As shown, a clearance space c, e.g., of 1 mm, is maintained between the beam dump structure and the wall of the chamber. Preferably, as shown, the structures are cooperatively shaped as in a labyrinth Ls to limit the outflow of the dopant gas or vapor, while maintaining thermal and electrical isolation of the dump structure 11′ from the walls of the ionization chamber, maintaining electrical isolation of the beam dump 11′ while preventing loss of dopant gas or vapor. In the embodiment of FIG. 4C electrical insulation Z fills the space between the beam dump and the wall of the ionization chamber, maintaining electrical isolation of the beam dump 11′ while preventing loss of dopant gas or vapor. Referring to FIGS. 4D and 4E, a thermoelectrically or water-cooled outer housing Hc defines a space into which a chamber-defining member 5c of heat-conductive and electrically-conductive material is removably inserted with close operational fit. Gas inlets Gi introduce conductive gas of a subatmospheric pressure (e.g., between 0.5 and 5 Torr), that is significantly higher than that of the operational vacuum Vo within the overall ion source housing 49 which contains the ionization chamber assembly. The conductive gas (for example, N2, Ar, or He) is introduced to the interface If between matching surfaces of the housing and the chamber in regions remote from exposure of the interface to operational vacuum Vo, and isolated from the vaporizer and process gas feed lines. In a preferred embodiment, the cooling gas is fed through an aluminum block or cooled housing and exits between the demountable ionization chamber and the block or housing, at the interface between them, into cooling channels machined into the aluminum block. The cooling channels have the form of linear grooves (e.g., 1 mm wide by 0.1 mm deep) which populate a significant percentage of the surface area between the two mating components. This construction allows the flat mating surfaces (the grooved aluminum surface and the flat surface of the separate ionization chamber) of the two components to mate flush with one another. Simple elastomeric o-rings encompass the surface area which contains the cooling channel grooves, ensuring that the gas confined to the cooling channels is isolated from regions which contain feedthroughs and passages for process gas or vapor within this interface, and also isolates the cooling gas from the ionization volume and from the vacuum housing. The spacing between those surfaces and the pressure of the conductive gas in the interface are so related that the mean-free path of the conductive gas molecules is of the order of or less than the spacing of opposed surface portions at the interface. The conductive gas molecules, by thermal motion, conduct heat across the interface from the chamber wall to the surrounding cooled housing elements. Any regions of actual physical contact between the solid material of the chamber body and of an outer housing element likewise promotes cooling by conduction. It is to be noted that the mode of conductive gas cooling described here does not depend upon convectional gas flow, but only upon the presence in the interface of the gas molecules. Therefore, in some embodiments, it may be preferred to form seals at the interface to capture the gas, as discussed above, although in other embodiments exposure of the interface at edges of the assembly with leakage to the operational vacuum Vo can be tolerated just as is the case with respect to cooling of semiconductor wafers as described, e.g., in the King U.S. Pat. No. 4,261,762. In other embodiments, the cooling housing of the ionization chamber assembly or similar side wall elements of other structures of the ion source are water-cooled in the manner of cooling the mounting frame 10 as described herein. In some embodiments, depending upon the heat load on the ionization chamber, the heat conduction resulting from the inclusion of thermally conductive gasket seals, as well as regions of physical point contact between the matching surfaces of the chamber and housing elements is sufficient to keep the chamber within the desired temperature range, and the conductive gas-cooling feature described is not employed. It is recognized that the heat-transfer relationships described here have general applicability throughout the ion source and the other structural components of the implanter as well. Thus, the temperature of the vaporizer may be controlled by the heat transfer from a disposable crucible to surrounding elements via gas conduction at an interface, for operating conditions which require less than, for example, 2 W/cm2 of heat transfer through the gas interface. Likewise, surfaces of the electron gun, the electron beam dump, the mounting frame and the aperture plate may serve as conductors via a conductive gas interface to temperature-control elements such as the thermoelectrically or water-cooled housing that has been described, as illustrated in FIG. 4E. FIGS. 4F and 5 show different sizes of a broad, collimated electron beam passing through the ionization chamber, the profiles of these beams matched in profile to the wide and narrower apertures of the respective ionization chambers of FIGS. 4F and 5. FIG. 6 shows the ion exit aperture plate 13 with the axis of the ion beam directed normal to the plane of the paper. The dimensions of the exit aperture plate conform to the dimensions of the ionization chamber within body 5, approximately 7.6 cm tall×5.1 cm wide. The exit aperture plate contains an opening 37 which is approximately 5.1 cm in height, s, by 1.3 cm wide, r, suitable for high current implanters, and has a bevel 38 to reduce strong electric fields at its edges. It is matched by a broad, collimated electron beam having width g of 19 mm and depth p of 6 mm, cross-sectional area of 114 square mm. The aperture of the embodiment of FIG. 5, has similar features but a much narrower width, e.g. a width r1, 4 mm, matched by an electron beam of width g1 6 mm and a depth p1 of 6 mm. FIG. 7 shows the shape of the cathode 33, or electron emitter. In a preferred embodiment, it defines a planar emitting surface, it's dimensions being roughly 15 mm long×9 mm×3 mm thick. It can be directly heated by passing an electric current through it, or it can be indirectly heated, as shown, with an electric current flowing through filament 39 via leads 40, heating it to emit thermionic electrons 41. By biasing the filament 39 to a voltage several hundred volts below the potential of cathode 33, thermionic electrons 41 heat the cathode 33 by energetic electron bombardment, as is known in the art. FIG. 8 illustrates the assembly of an ion source according to FIG. 3A into a retrofit volume 60 of a previously installed ion implanter while FIG. 8A illustrates the complete ion implanter. In this particular embodiment nothing has been disturbed except that the Bernas ion source for which the implanter was originally designed has been removed and, into the vacated volume 60, the ion source of FIG. 3A has been installed, with its flange 7 bolted to the ion source housing flange. The extraction electrodes 53 remain in their original position, and the new ion source presents its aperture 37 in the same region as did the arc discharge Bernas source. The magnet coils 54 are shown remaining, available e.g., for operation in reflex mode if desired, or for applying a containment field for electrons proceeding to the beam dump 11. As shown in FIG. 9 the usual gas connections are made enabling dopant gases from sources 1, 2, 3, and 4 in the supply rack 76 of the gas box 70 to be connected via inlet conduit 74 and exhausted via conduit 72 to high vacuum system 78. Lone E-Beam Gun Retrofit Embodiment Referring to FIG. 9, an extended E-Beam gun is uniquely associated with an ionization chamber. The gun has zoom optics, and comprises the following components: extended housing 79, feedthroughs 80, mounting flanges 81 and 81′, cathode 82, extraction stage 83, collimation lens 84, zoom lens 85, and turning stage 87 comprising a 90 degree mirror. The long gun housing 79 lies along an axis A′ parallel to the direction A of emission of the ion beam from the ion source, and within the retrofit space 60 of the previously installed implanter ion source. The housing extends from the feedthrough terminals 80, resident outside of the mounting flange 7 of the ion source, past a vacuum pump 58, terminating at mounting flange 81′ and the main ion source mounting flange 7. The electron beam optics continue alongside the ion source block 5 to a point in registry with the electron inlet port 35 of the ionization volume 16. The feedthroughs comprise appropriate fittings for the power and control lines for the cathode and other stages of the gun, and cooling water inlet and outlet for the housing, which is cooled, at least in the vicinity of the cathode. In an alternate embodiment, special cooling of the gun housing is not employed, the remoteness of the cathode, as shown in FIG. 9, ensuring that the ionization chamber 5 s not heated by the cathode, and any necessary cooling for protection of the vaporizer or operating personnel being achieved by conduction to water cooled mounting flanges or the like. With significant cost and size efficiencies, the cathode 82 is of relatively small size in comparison to the profile dimension of the largest broad, aligned electron beam that is to transit the ionization volume 16. It is preferably a resistance-heated or indirectly heated, planar cathode emitter plate (such as plate 33 described above in connection with FIG. 7), made of lanthanum hexaboride (LaB6) or of refractory metal such as tantalum or tungsten, to emit a generally uniform stream of electrons to the high voltage electron extraction stage. As shown in FIG. 9A the ion source of FIG. 9 is retrofit into vacated volume 60 of a previously installed ion implanter. The compact nature and arrangement of the ion source locates the prime heat source, the cathode, remotely from the ionization chamber 16 such that its heat does not contribute to disassociation of the fragile dopant molecules. In the case of FIGS. 9A and 9B, heat from the ionization chamber is conducted to the vaporizer and is controlled by its temperature control. During operation, the vacuum pump 58 in the region of the cathode 82 intercepts back-streaming gas which has escaped from the ionization chamber 16 via the electron inlet port 35. This has the important advantage of protecting the remote cathode 82 from contamination, and enables a very extended cathode life, a feature which is especially important to enable use of the preferred LaB6 cathodes, which are particularly sensitive to degradation from chemically active species. Water Cooled Block and Demountable Ionization Chamber In the embodiment of FIG. 9B (see also FIG. 3E) the ionization volume 16′ is defined by a demountable end module 5b which is mounted with conductive thermal contact on the end of solid mounting block 5a via thermally conductive seal 6″. For achieving demountability, the conductive seal 6″ is compressed via metal screws through mating surfaces of the block 5a and the demountable end module 5b. This construction enables the member Sb defining the ionization chamber 16′ to be removed from the block 5a and replaced with an unused member, advantageously of disposable construction. It also enables a different, and in some cases more efficient cooling of walls of the ionization chamber 16′ than in previous embodiments. For construction of the demountable member, in addition to aluminum (which is inexpensive and less injurious to the wafers being implanted than molybdenum, tungsten or other metals if transported to the wafer in the ion beam), the ionization chamber member 5b and exit aperture plate 13 are advantageously constructed from graphite or SiC, which removes altogether the possibility of metals contamination of the wafer due to propagation from the ion source. In addition, demountable ionization chambers of graphite and SiC may be formed cheaply, and thus can be discarded during maintenance, being less expensive to be replaced than a one-piece structure. In another embodiment, for conductively controlling the temperature of the block 5a and the chamber body 5b, they have mating smooth surfaces, the surface of the block containing machined cooling channels which admit conductive cooling gas between the block 5a and the chamber body 5b, so that that gas, introduced under vacuum, transfers heat by heat conduction (not convection) in accordance with the above description of FIGS. 4D and 4E, and cooling techniques used for the different situation of cooling wafers that are being implanted, see King U.S. Pat. No. 4,261,762. In this case, gaskets at the vapor and gas passages prevent mixing of the conductive heat transfer gas, such as argon, with the gas or vapor to be ionized. As shown, block 5a is cooled by water passages 24a, either associated with its own thermal control system, FIG. 3E, or, as shown, in FIG. 9B, associated with the cooling system 24 that cools frame 10 on which the beam dump 11 is mounted. By being based upon heat conduction through solid members, water contact with the walls of the ionization chamber is avoided, making it uniquely possible to fabricate the ionization chamber of materials, such as low cost machined or molded graphite, which cannot conveniently be exposed to water. The remote location of the cathode and its heat effects combine with these mounting features to achieve desired cool-running of the ionization chamber. Advantageous E-Beam Gun Features Features of particularly preferred embodiments of the long E-Beam are shown in FIG. 10, with the extraction stage 83 shown in greater detail in FIG. 11. The extraction stage 83 is of cylindrical geometry, and comprises a cathode 82, a field shaping grid electrode 100, Wehneldt electrode 101, cylinder lens 102, and anode 103. Relative to the cathode potential Vc, the grid potential Vg is held, for example, at −2V<Vg<+4V and the anode potential V1 is maintained at between about 200 and 1000 volts positive, depending on the desired electron energy at the exit of the extraction stage. The Wehneldt and cylinder potentials, Vw and Vs, respectively, are tuned so as to produce electron trajectories through the extraction stage which limit filling of its lenses, and limit the beam angle of the electron trajectories at the output of the extraction stage. In essence, the purpose of the extraction stage is to collect the thermionically emitted electrons from the directly heated cathode or from the emitter surface of an indirectly heated cathode, to provide a beam of significantly energized electrons in a beam with a desired regular profile, with a degree of uniformity of electron distribution and collimation that presents a good quality object for the downstream telescopic lens system shown in FIG. 10. Such tuning is shown in FIG. 12 for an extraction stage which was originally developed for low-energy positrons (see I. J. Rosenberg, A. H. Weiss, and K. F. Canter, Physical Review Letters 44, p. 1139, 1980). It is modified and used for forming a broad electron beam as part of the present invention. The original extraction stage described by Rosenberg et al. was essentially a 100% positron transmission stage designed for an extended, 10 mm diameter positron emitter. In the present E-Beam gun, the extraction stage is scaled smaller, e.g. by a factor of 0.5 to accommodate a 5 mm diameter cathode electron emitter with the aperture diameter of grid electrode 100 5 mm and the sign of the electrode potentials reversed to make the structure suitable for extraction of electrons. With this scale factor, the electron extraction stage is approximately 27 mm long, with the cylinder lens diameter being 17.5 mm. In FIG. 11, typical dimensions may be: d = 5 mm l1 = 1.3 mm d1 = 9.5 mm l2 = 2.3 mm d2 = 17.5 mm l3 = 4.8 mm d3 = 9.5 mm l4 = 18 mm Where Vc=any range between −20 to −300 or −500 V, relative to Vch, the potential of the ionization chamber. Relative to Vc, then, the other voltage values for instance, may respectively range between: −2V<Vg<4V 0V<Vw<500V 50V<Vs<500V 200V<V1<1000V Other embodiments of the electron extraction stage are possible. In one embodiment, the emitting surface of the cathode 82 is moved forward to lie in the same plane as the grid 100, field shaping provided by the grid aperture not being employed. In this case, grid 100 is held at the same potential as cathode 82. Another advantageous embodiment of the extraction stage incorporates a Pierce geometry, in which the grid aperture is coplanar with the cathode, but the shape of the grid is conical, with sides inclined at an angle of 22.5°, corresponding to a cone angle of 135° (see J. R. Pierce, Theory and Design of Electron Beams, 2nd edition, Van Nostrand, N.Y., 1954). This electrode shaping advantageously counteracts the effects of electron space charge in the highly populated vicinity of the cathode. In the presently preferred embodiment, the 5 mm-diameter, circular thermionic cathode plate is heated to emit an average electron current density of about 200 mA/cm2 from its face having an emitting area of 0.2 cm2, yielding 40 mA of electron current into the extraction stage. The extraction stage serves as an injection stage for the following lens system which comprises collimating lens 84 followed by zoom lens 85. In the preferred embodiment, these lenses comprise 17.5-mm-diameter (“D”), thin-walled metal cylinders, separated by gaps equal to 0.10 D. When differing potentials are applied to the thus separated cylinders, strong focusing fields are generated at the gaps, producing lensing effects. Referring to FIG. 10, the collimating lens 84 is an asymmetric einzel lens, that is, it consists of three coaxial cylinders of length 2 D, 1 D, and 2 D at voltages V1, V12, and V3. V1 is not equal to V3 (hence the Einzel lens is “asymmetric”). In general, the three elements (triplet) of each einzel lens acts as a single “thick” lens. In the case of collimating einzel lens 84, V2>V1, and lens 84 acts as an accelerating lens. V12 is varied to adjust the focal length, hence the magnification of the triplet. Lens 84 also acts to limit overfilling of the cylinders by the electron beam, which can produce aberrations and beam loss. As described, collimating lens 84 presents an object to the downstream zoom lens 85 with appropriate beam characteristics to enable the zoom lens 85 to produce a collimated, variable-energy beam for passage into the 90° mirror 87. In electron optics, a zoom lens accomplishes the function of changing the energy of the electron beam while maintaining the same object and image locations. A typical zoom lens is a three-element lens consisting of concentric hollow metal tubes in series held at voltages v1, v12, and v2, respectively. Typically, the center element is shorter in length than the first and third elements (e.g., see lens 84 in FIG. 18). In this case, v1 establishes the entrance energy, and v2 the exit energy. The ratio (v2/v1 for acceleration, and v1/v2 for deceleration) is called the “zoom ratio”. For a given value of v1 and v2, the value of the center element voltage, v12, is selected to maintain the focal lengths (and hence the object and image locations, P and Q, respectively) of the lens. Zoom lenses of this type are useable over a limited energy range (the “zoom range”). The five-element zoom lens 85 preferably employed in accordance with the present invention and illustrated in FIG. 13 is an extension of this concept. By adding additional lens elements, this compound lens offers the following expanded capabilities versus a three-element lens: 1) It can be operated over an extended zoom range, e.g., 20:1 versus 5:1 for a three-element lens. 2) It can vary angular magnification and be operated in an “afocal mode”, that is, by tuning the voltages so that the electron trajectories entering the lens are parallel upon exit, i.e., there is no real focus at the lens exit. 3) It can be operated as a “telescopic” lens, which produces a real image with a well-defined value of P and Q, but with variable linear magnification. For example, when AEL1 is a stronger focusing lens (shorter focal length) than AEL2, M>1; and when AEL2 is the stronger focusing lens, M<1. 4) The five-element lens can provide variable linear and angular magnification while also allowing zoom control, i.e., varying both energy and magnification. For example, we refer to FIGS. 13A through 13D, which show the five-element zoom lens as two three-element lenses, AEL1 and AEL2, in tandem. In general, the electron beam will be at different energies entering and exiting the zoom lens, as previously discussed. In addition, several modes of operation are illustrated by the figures. FIG. 13A shows the afocal mode, where the electron beam is well-collimated exiting the lens, corresponding to an image at infinity. This mode is advantageous for collimating the beam prior to its entrance into a turning stage, such as the 90 degree mirror 87 described with reference to FIGS. 9, 9B and 10. It is also advantageous for injecting a well-collimated beam of the desired energy into the ionization chamber, to maintain the beam substantially parallel with an elongated extraction aperture. FIG. 13B shows the beam being focused to an image with unity magnification. This mode is desirable when a high degree of collimation is not necessary, and preservation of the beam characteristics at the object location is desired at the image location, for example, when the object dimension is appropriate for the size of the beam profile in the ionization chamber when the zoom lens is being used primarily for modifying the energy of the electron beam. FIG. 13C shows the beam being focused to an image smaller than the object, which is appropriate for injection into a mirror or into the ionization chamber when counteraction of space charge forces in the electron beam is desired, to prevent the beam from expanding overmuch, as when the zoom action is employed to decelarate the beam. This mode is also advantageous for producing a narrow cross-section electron beam in conjunction with a narrow ion extraction aperture, e.g., in a medium or low current ion implanter. FIG. 13D shows the beam being focused to an image larger than the object. This mode is advantageous to expand the electron beam prior to injection into the ionization volume to provide a large cross-section ionization region, as in the case of a wide ion extraction aperture in a high-current ion implanter. In conjunction with the input collimating lens 84, the lens system can exercise control of linear and angular magnification, energy, and image location over a wide range, more than sufficient for the needs of the present invention. The zoom lens 85 is comprised of two asymmetric einzel lenses in tandem, einzel lenses 104 and 106 in FIG. 10, and AEL1 and AEL2 in FIG. 13. The zoom lens 85 is a five-element lens, with its center (third) element, 3 D length, serving as an element of each of the tandem einzel lenses. FIG. 13 shows an Object and Image for AEL1 (the Image is an Object for AEL2) which results in a final image at infinity, producing collimated electron trajectories. Zoom lens 85 is capable of being operated as an afocal lens by setting its element voltages such that the second focal point of AEL1 and the first focal point of AEL2 overlap. In this mode, the zoom lens 85 is telescopic; parallel electron trajectories entering the lens are also parallel upon exiting. In the case, however, that V2>V3>V4, the zoom lens advantageously decelerates the electrons over a wide energy range, and can still retain its telescopic properties if the voltage differences, i.e. V23 and V34, are adjusted appropriately. A positron lens structure of the type shown in FIG. 11, is shown in T. N. Horsky, Ph.D. thesis, Brandeis University Dept. of Physics, Semiconductor Surface Structure Determination via Low Energy Positron Diffraction: Cleavage Faces of CdSe, UMI Pub # 9010666, Chapter 3, 1988. FIG. 14, taken from that thesis, shows an example of a decelerating operating mode, in which lens element potentials Vi are expressed in kinetic energy units, i.e., kinetic energy=e|Vi−Vc|. The positron beam entered the zoom lens at 1 keV, and decelerated to a beam energy of 75 eV upon exiting AEL1 (i.e., within lens element V3). The plot shows how V34 was varied as a function of positron final beam energy to maintain a collimated output, for a final beam energy range between 5 eV and 250 eV. The plot is indicative of plots obtainable with the similar electron beam lens structure presented here. In the present novel embodiment, the collimating electron lens 84 is tuned in conjunction with the zoom lens 85 to vary linear magnification as well as final electron beam energy. Thus, a variable-energy, variable-diameter electron beam can be generated with the lens system depicted in FIG. 10, with the advantage of copious electron production enhanced by the acceleration geometry, while achieving lower final electron energy appropriate for interaction with dopant feed material, e.g., with decaborane, by use of the deceleration stage. Prior to entering the ionization volume 16 of ionization chamber block 5, the electron beam produced by the gun of FIG. 10 is turned through 90°. The turning stage 87 can be of various known forms, e.g., two related and coaxial partial cylinders (i.e., a radial cylindrical analyzer), formed into respectively inside and outside sides of an elbow that bends the electron optical axis, the partial cylinder that lies on the inside of the curved axis being maintained at a more positive potential than the partial cylinder lying on the outside of the curved axis. These cooperate to turn the beam 90 degrees according to known electron path bending techniques. A mirror defined by two flat or cylindrically curved plates (i.e., either a parallel plate or cylindrical mirror analyzer) whose axis is oriented 45° from the zoom axis to result in a 90° deflection at the exit of the mirror, can also be employed to occupy a smaller space within the retrofit volume. It is presently preferred, however, that the described radial cylindrical analyzer be employed with the advantage of achieving two dimensional transformation of the beam to the new path through the ionization space 16 of the ionization chamber 5, thus preserving the pre-established beam profile with high transmission. After turning, the beam passes through a limiting aperture 10′ which is advantageously rectangular, and enters the ionization chamber 5 via the electron entrance port 35. Limiting aperture 10′ is constructed to be replaceable in coordination with replacing the ion extraction aperture, typically the wider the ion extraction aperture, the larger is the corresponding dimension of the selected electron limiting aperture 10′. In operation with the turning mirror, at low electron energies, space charge forces can affect control of the electron beam. According further to the invention, two different modes of using the long E-Beam gun with a 90 degree turning mirror are provided, that successfully deal with this. E-Beam Mode 1: The deceleration capabilities of the zoom system are employed in conjunction with the acceleration capabilities of the preceding collimating lens, to provide an acceleration-deceleration mode of operation. For instance, the lens voltages are coordinated to cause the system to zoom down from, e.g., one keV at the entrance to the zoom system to 100 eV at its exit. Because the beam expands due to the deceleration, some electrons of the beam may be lost within the mirror, but this is readily acceptable where low current, low energy injection into the ionization volume 16 is desired. For example, the system is operable at currents less than 5 mA at 100 eV, or at higher energies. As the final energy of the electrons goes up, the electron current increases. The electron beam in this case can be well collimated and be aligned with a relatively small area beam dump. E-Beam mode 2: In this case, the electrons are transported at high energy throughout the E-Beam gun and mirror, and a deceleration stage 88 is interposed between the exit aperture of the mirror and the entrance of the ionization volume 16. Because the beam is collimated at high energy, the electron optics perform without detrimental space charge effect, delivering a well-collimated beam sized for the mirror. Following the mirror, the beam is caused to decelerate abruptly as it enters the ionization chamber, to expand with the electron trajectories confined to a conical, gradually expanding volume. In this case, electron currents of 20 mA or more, for example, may be obtained. As the beam expands, since the electron trajectories remain generally straight, the beam can be intercepted by a beam dump 11 of larger area than in mode 1. Along the ionization path in this case, those electron trajectories which diverge to pass more closely to the aperture are somewhat offset by those which diverge further from the aperture so that total ions extracted along the aperture need not vary in density to an unacceptable degree along the length of the aperture. For this mode of operation, having the beam dump area large (with the beam dump in close proximity to the wall of the ionization chamber to limit gas conductance), the beam dump is sized still to align with the somewhat diverging electron paths so that substantially all electrons of the E-Beam from the mirror are intercepted by the cooled beam dump. In the case an elongated electron gun is mounted with its axis aligned with the ionization path through the chamber (no mirror employed), mirror loss of the beam can be avoided, and a collimated electron beam, produced as in mode 1, can be maintained through the ionization chamber, at a larger electron current. The operation of such systems have numerous advantages under conditions of operation appropriate to producing the ion beams illustrated in different circumstances such as shown in FIGS. 4D and 5. The system can produce different size profiles of the broad area beams aligned with the beam dump, and different electron densities suitable for respectively different situations over a wide range of preferred operation, e.g. over a zoom ratio of 15 to 1. Cost efficiency, space efficiency and thermal advantages especially result by use of a relatively small cathode, while achieving a relatively broad and controlled-energy beam. The system is useful, first with respect to decaborane at electron beam energies of between about 20 to 150 eV, and with many important or novel other species. The different energy regimes up to, e.g. 300 or 500 eV can enable the system to operate, in broad, aligned electron beam mode with respect to all species—(including the fluorides for small, but highly pure beams). In a specially constructed multi-mode ionization system, the system can be switched to a reflex ionizing mode for some species (e.g. hydrides and fluorides) using a confining magnetic field. It can also be operated to produce doubly charged phosphorus or arsenic, and triply charged species. Electron Injection for High Current Applications For some ion implant applications, it is desired to obtain an ion current approaching the highest ion currents of which the technology is capable. This depends critically on the value of electron beam current traversing the ionization chamber, since the ion current produced is roughly proportional to the value of this electron current. The electron current injected into the ionization chamber is limited by the effects of space charge forces that act on the electron trajectories within the electron gun optics and the ionization chamber. In the space charge limit, these forces can add an increased width to a tightly focused beam waist produced by a lens, and can introduce an increased angular divergence to a beam as it diverges downstream of the waist. I note the relevance here of the principle that the maximum electron current which can be transported through a tube of diameter D and length L can be produced by focusing the beam on a point at the center of the tube with an angle α =D/L expressed in radians. In such case, the maximum current is given by: Imax=0.0385V3/2α2, (1) where Imax is the electron current measured in mA, and V is the voltage in volts corresponding to electrons of energy E=eV, where e is the electronic charge. Also, in this example the minimum waist diameter w is given by w=0.43 D. Inserting α=15° and V=100V into equation (1) yields Imax=10 mA, whereas inserting α=5° and V=1000V yields Imax, =106 mA. By interpreting a as the angular divergence induced by space charge forces, these examples demonstrate the advantage achieved by the novel embodiment of FIG. 18 which transports the space charge-limited beam at high energy and achieves a large injected electron current at desired lower energy. The gun of FIG. 18 is similar to that of FIG. 10, but has important differences: 1) instead of the zoom lens 85, a double-aperture lens 88 is employed, which terminates at the entrance port of the ionization chamber and 2) no mirror 87 is used, the gun being mounted coaxial with the long axis of the ionization chamber. In a preferred embodiment having these features, large-diameter tubes (approximately 2.5 cm diameter) are used to limit lens filling, and hence beam loss due to aberrations. The gun is kept short by using the collimating lens to present the desired beam characteristics to the final double-aperture lens (DAL) for injection into the ionization chamber. Provisions are made so that the electron gun voltages (Vg, Vw, Vs, V1, V12, all referenced to the cathode voltage Vc) are tunable to give the best performance in terms of beam current, angular divergence, and beam diameter appropriate to a given application, and will operate at fixed values, with a beam energy Ei at the exit of collimating lens 84 (i.e., Ei=e[V2−Vc]) between 750 eV and 1250 eV. Thus, the wide-range zoom capability provided by the gun of FIG. 10 is not required; the tetrode extraction gun 83 in combination with the three-element collimating lens 84 provides sufficient flexibility to control and to properly determine the electron beam characteristics. The DAL then functions as a strongly focusing decelerating lens, with the desired electron energy within the ionization chamber being given by Ef=e[Vch−Vc], where Vch is the ionization chamber potential (when Vch is referenced to earth ground, it is the ion beam accelerating potential Va). For example, with Ei=1000 eV and Ef=100 eV, the DAL is a 10:1 decelerator. In the presently preferred design of the DAL, it is comprised of two flat plates with equal diameter circular apertures of diameter D′. The plates (of thickness 0.1 D′) are separated by a uniform distance D′/2, and are constructed of vitrified graphite, silicon carbide, or aluminum to eliminate transition metal contamination due to beam strike on the apertures which could result if tantalum, molybdenum, or stainless steel electrodes were used. For example, values of D′=1.2 cm±0.6 cm will accommodate much of the useful range of this lens. Importantly, since one plate of the DAL is tied to V2 and the second plate is tied to Vch, the addition of this lens does not require a further power supply. The DAL serves two useful purposes: 1) it accomplishes deceleration of the electron beam, in a controlled and well-defined manner, to the selected value of Ef necessary to maximize ionization efficiency of the particular dopant feed gas of interest, and 2) it provides strong focusing of the electron beam to counteract space charge effects which would otherwise dominate the spreading of the electron trajectories within the ionization volume. I further recognize the advantage here of the principle that, in order to maximize the electron current through a tube, the beam should be focused at the center of the tube length. According to the present invention, when injecting the space charge-limited electron beam into the field-free volume of the ionization chamber, the spreading of the beam is minimized by focusing the beam at the center of the volume's length. In the case of an ion source according to FIG. 18, the nominal focus is located a distance of about 4 cm from the principal plane of the DAL. The optics for this are shown in more detail in FIG. 18A. An object O′ is presented to the DAL by the upstream lens, and a corresponding image I′ of this object is produced by the DAL. The values used for this model are: V2/Vch=10, D′=1.27 cm, object distance P=4.8 D′, image distance Q=3 D′, linear magnification M=1.0 (taken from E. Harting and F. H. Read, Electrostatic Lenses, Elsevier, N.Y., 1976). Thus, in this embodiment the electron beam is focused to an image point 3.8 cm from the principal plane of the DAL, approximately in the center of the length of the ionization chamber. By varying the lens ratio V2/Vch and/or changing the position of the object, the location of this image point can be moved to optimize the performance of the ion source in relation to other operating parameters (for example, the image can be moved further downstream, so that the minimum waist diameter of the beam, i.e. the circle of least confusion, falls near the center of the chamber). The maximum extent of the space charge spreading of the beam may be estimated through use of equation (1), rearranging it as below: D=5.1LImax1/2V−3/4 where D is the diameter intercepted by the electron flux, and L is the length of the ionization chamber (approximately 7.6 cm). Substitution of Imax=20 mA and V=100V yields D=5.5 cm, as does substitution of Imax=40 mA and V=168V. Indeed, in practice, the space charge spreading in the ionization chamber will be less than approximated by equation (2) due to the space-charge compensation provided by the positively-charged ions which are abundantly present in the ionization volume. FIG. 18 and FIG. 18A employ an enlarged electron exit port and beam dump 36 to intercept the vast majority of the electrons in the beam. By keeping the separation between the beam dump 11 and the ionization chamber small, the gas flow out of the ionization volume through the exit port 36 can be small. Several advantageous features of the ionization chamber and ion extraction aperture are also shown in FIG. 18A: 1) a counterbore is provided in the chamber wall to receive the thin aperture plate in such a way as to maintain a uniformly flat profile, to establish a uniform electric field between the aperture plates; 2) the ion extraction aperture 37′ is moved closer to the center of the chamber (by up to about 8 mm, or 25% of the width of the chamber) for more efficient removal of ions by the extraction field of the extraction optics, and a shorter ion path through the ionization volume which reduces the probability of ion-neutral gas collisions, resulting in an asymmetric location in the chamber of the electron entrance-exit axis; 3) the ion extraction aperture plate is biased to a negative voltage VE (where −25V<VE<0V) with respect to the ionization chamber to further increase the drift velocity of the ions, and hence the maximum obtainable current in the resulting ion beam. Referring to the embodiment of FIGS. 19-19B, biasing of the aperture plate is accomplished by forming it of an insulating material such as boron nitride, coating the exterior and interior surfaces which are exposed to the ions with an electrically conductive material such as graphite, and electrically biasing the conductor. In other embodiments insulator standoffs are employed, see FIG. 19C, to join the electrically conductive extraction aperture plate to the chamber while maintaining its electrical independence. In embodiments of this feature, gas loss from the ionization chamber at the edges of the aperture plate can be minimized by interfitting conformation of the edges of the electrically isolated aperture plate and the body of the ionization chamber (involuted design) to effect labyrinth seal effects such as described in relation to FIG. 4B. In accordance with the embodiment of FIGS. 20A, B and C, an electrically conductive aperture plate insert is mounted in an electrically insulating frame which holds the aperture plate in place, and provides an electrical contact to the insert. The embodiment facilitates change of aperture plates in accordance with changes of the type of implant run. In some embodiments thermoelectric coolers may be associated with the aperture plates to keep them from over-heating. In other embodiments, an extension of cooled frame 10 or a separate cooled mounting frame is employed to support the aperture plate. Retrofit Embodiment of High Current Source FIG. 18B shows the introduction of the embodiment of FIG. 18 and FIG. 18A into the ion source housing of a retrofitted implanter. Preferably the electron gun is mounted at the top, as shown. To implement this geometry into an existing implanter, a new ion source housing is provided, constructed in accordance with typical Bernas ion source considerations, (it can receive a Bernas ion source if ever desired), but the housing is modified at the top to receive the electron gun. In another case the existing ion source housing is modified, e.g. by the removal of the magnet coils 54 and the insertion of a vacuum port at the top of the housing to receive the flange-mounted, vertical electron gun assembly. Since the implementation of an external, axial magnetic field can in certain cases be useful, a small pair of magnet coils is provided, as also shown in FIG. 18B. The electron gun as shown here, is mounted coaxially within one of those coils in a space efficient and uniquely cooperative arrangement. When these magnet coils are energized, the resultant axial magnetic field can confine the primary electron beam (both within the electron gun and in the ionization chamber) to a narrowed cross-section, to reduce the spreading of the electron beam profile due to space charge, and increasing the maximum amount of useful electron current which can be injected into the ionization volume. For example, a magnetic flux density of 70 Gauss will act to confine 100 eV electrons within the ionization volume to a column diameter of about 1 cm. Since the electron emitter of this long electron gun is remote from the ionization chamber, it will not initiate an arc discharge, while, depending on the strength of the external magnetic field, it will provide a low-density plasma within the ionization region. By controlling this plasma to a low value, multiple ionizations induced by secondary electron collisions with the ions can be controlled to acceptable levels in certain instances. Furthermore, it is realized that the presence of the low-density plasma, in some instances, can enhance the space charge neutrality of the ionization region, and enable higher ion beam currents to be realized. In a multi-mode embodiment, larger magnets are employed in the relationship shown in FIG. 18B to enable larger magnetic fields to be employed when operating in reflex mode, or when a Bernas arc discharge source is desired to be used. Universal Ion Source Controller A universal controller for the ion source of the invention uniquely employs the user interface that is used with arc discharge ion sources such as the Bernas and Freeman types. FIG. 15 shows, in diagrammatic form, a typical control system 200 for operating a Bernas type ion source. The operator for such existing machines programs the implanter through an Operator Interface 202 (OI), which is a set of selectable graphical user interfaces (GUI's) that are selectively viewed on a computer screen. Certain parameters of the implanter are controlled directly from the OI, by either manually inputting data or by loading a predefined implant recipe file which contains the desired parameters that will run a specific implant recipe. The available set of GUI's includes controls and monitoring screens for the vacuum system, wafer handling, generation and loading of implant recipes, and ion beam control. In many implanter systems, a predetermined set of ion source parameters is programmable through the Beam Control Screen of the OI represented in FIG. 15, including user-accessible setpoint values for Arc Current, Arc Voltage, Filament Current Limit, and Vaporizer Temperature. In addition to these setpoints, the actual values of the same parameters (for example, as indicated by the power supply readings) are read back and displayed to the operator on the OI by the control system. Many other parameters that relate to the initial set up of the beam for a given implant are programmed and/or displayed through the Beam Screen GUI, but are not considered part of the operator's ion source control. These include beam energy, beam current, desired amount of the ion, extraction electrode voltages, vacuum level in the ion source housing, etc. As indicated in FIG. 15, a dedicated Ion Source Controller 204 reads and processes the input (setpoint) values from the OI, provides the appropriate programming signals to the stack of power supplies 206, and also provides read backs from the power supplies to the OI. A typical power supply stack 206 shown in FIG. 15, includes power supplies for the Arc, Filament, and Vaporizer Heater, power supplies 208, 210 and 212, respectively. The programming and power generation for the Source Magnet Current may be provided in the screen, but is typically provided separate from the Ion Source Controller in many machines of the presently installed fleet. FIG. 15a shows the same elements as FIG. 15, but for a Bernas-style ion source of the kind which uses an indirectly-heated cathode (IHC). FIG. 15a is identical to FIG. 15, except for the addition of a Cathode power supply 211, and its read back voltage and current. The additional power supply is necessary because the IHC (indirectly heated cathode element) is held at a positive high voltage with respect to the filament, which heats the IHC by electron bombardment to a temperature sufficient that the IHC emits an electron current equal to the Arc Current setpoint value provided through the OI. The arc control is accomplished through a closed-loop control circuit contained within the Ion Source Controller. FIG. 16 shows diagrammatically the functional design of the Electron Beam Ion Source Controller 220 of the present invention. Control of electron current from the electron gun directed to the beam dump 36 is accomplished by a closed-loop servo circuit within the controller 220 which adjusts the electron emitter temperature and the electron gun grid potential to maintain the desired electron current setpoint. The Controller 220 is designed to be retrofittable into a typical existing implanter, both functionally and mechanically, and to do so with essentially no change to the controls software of the implanter. In order to achieve mechanical retrofittability, the Controller electronics 220 and Ion Source Power Supplies 207 occupy a similar physical volume in the gas box as did the existing Bernas Ion Source Controller 204 and Power Supplies 206. In order to preserve the integrity of the implanter's existing controls software, the Controller 220 is constructed to accept the existing inputs from the OI 202 and to provide the read backs expected by the OI. Thus, the operator can program the Ion Source 1 of the present invention from the OI in the manner to which the operator has long been accustomed, without change. This functionality is accomplished by a configurable Universal Translator circuit board 222 contained within the Controller 220, which accepts analog or digital inputs from the OI 202, and converts these inputs to the appropriate programming signals for the control of the Electron Beam of the ion source 1 of the present invention. This signal processing includes, as appropriate, digital-to-analog conversion, 16 bit digital-to-20 bit-digital conversion, analog-to-digital conversion, signal inversion, and multiplication of the signal by a scale factor, for example, depending upon the type and manufacturer of the installed ion implanter into which the broad, aligned electron beam ion source is to be retrofit. In like manner, the configurable Universal Translator 222 then processes the read back signals provided by the Electron Beam Power Supplies 207, and reports back to the OI 220 in the digital or analog format expected by the OI. The configurable Universal Translator 222 is also configurable to the specific number and kinds of outputs required by the installed implanter control system, for example to differentiate between a Bernas source and an IHC Bernas source, which requires extra read back channels for cathode voltage and current and a different scale factor for the cathode current limit setpoint vis-à-vis the Bernas and Freeman ion sources. The configurable Universal Translator 222 accomplishes this by substituting the control variables as indicated in FIG. 16, and as also shown in Table II below, for the case of a directly heated cathode electron gun in the E-Beam ion source of the invention. In the case of the system being retrofit to replace an IHC Bernas source, the two variables in the screen related to cathode voltage and filament current are assigned the optional values of anode voltage and cathode heating current. In the case of an indirectly heated electron source being used in a retrofit E-Beam ion source according to the invention, the values of its cathode voltage and heating filament current can be substituted for the optional values listed. TABLE II Controls Variables OI Setpoint OI Setpoint E-Beam E-Beam OI Read Back OI Read Back (Bernas) (IHC Bernas) Setpoint Read Back (Bernas) (IHC Bernas) Filament Cathode Emission Emission Filament Cathode Current Limit Current Limit Current Limit Current Current Current Arc Current Arc Current Beam Dump Beam Dump Arc Current Arc Current Current Current Arc Voltage Arc Voltage E-Beam Cathode Arc Voltage Arc Voltage Energy Voltage Vaporizer Vaporizer Vaporizer Vaporizer Vaporizer Vaporizer Temperature Temperature Temperature Temperature Temperature Temperature — — — Anode* — Cathode Voltage Voltage Cathode* Filament Heating Current Current *optional Additional electron beam control settings, for example many of the lens voltages shown in FIG. 11, are not accessible to the user through the OI, but must be preset at the Controller. Some of these voltage settings are accessible manually through potentiometers on the front panel (which provides visual read backs through panel-mounted meters while others (for example, Vg and Vw of the long extraction gun and V3 and V34 of the zoom lens) are automatically set through firmware-based lookup tables resident in the Controller electronics. In general, the arc control of Bernas, Freeman, and IHC Bernas sources are accomplished through similar means, namely by on-board closed-loop control circuits contained within the Ion Source Controller. In order to physically retrofit the ion source of an existing ion implanter with an ion source of the present invention, the original ion source is removed from the source housing of the implanter, the power cables are removed, and the Ion Source Controller 204 and the power supplies 206 or 2061, i.e. the Filament Power Supply, Vaporizer Power Supply, Arc Power Supply, and Cathode Power Supply (if present) are removed from the gas box of the implanter. The Electron Beam Ion Source 1 of the present invention is inserted into the retrofit volume of the implanter, and the Electron Beam Ion Source Controller 220 and associated Power Supplies 207 are inserted into the vacated volume of the gas box. A new set of cables is connected. The desired mechanical configuration of the ion source is prepared prior to installation into the source housing of the implanter. For example, for decaborane production, a large width ion extraction aperture and a large dimension limiting aperture at the exit of the electron gun can be installed, to provide a large ionization volume. Additionally, if the implanter has installed a variable-width mass resolving aperture 44, the width of that aperture may be increased in order to pass a larger mass range of decaborane ions. Otherwise, the set-up proceeds in a conventional manner, modified according to the various features that are explained in the present text. In addition to the electron beam controls that have just been explained, a temperature control mechanism is provided for the vaporizer 2. The vaporizer is held at a well-defined temperature by a closed-loop temperature control system within the Controller 220. As has been explained above, the closed-loop temperature control system incorporates PID (Proportional Integral Differential) control methodology, as is known in the art. The PID controller accepts a temperature setpoint and activates a resistive heater (which is mounted to a heater plate in contact with the water bath (see FIG. 3), or in heat transfer relationship with the mass of the vaporizer body 29 (FIG. 3A) to reach and maintain its setpoint temperature through a thermocouple read back circuit. The circuit compares the setpoint and read back values to determine the proper value of current to pass through the resistive heater. To ensure good temperature stability, a water-cooled heat exchanger coil 21 is immersed in the water bath (in the case of the water-cooled vaporizer of FIG. 3), or a thermoelectric (TE) cooler 30 (in the embodiment of a solid metal vaporizer of FIG. 3A), or a heat-exchanger coil surrounded by heat-conducting gas (in the embodiment of a vaporizer utilizing pressurized gas to accomplish thermal conduction between the various elements as in FIG. 3F) to continually remove heat from the system, which reduces the settling time of the temperature control system. Such a temperature control system is stable from 20° C. to 200° C. In this embodiment, the flow of gas from the vaporizer to the ionization chamber is determined by the vaporizer temperature, such that at higher temperatures, higher flow rates are achieved. A similar temperature control system can be employed to control the temperature of conductive block 5a of FIG. 3E or 9B. As has also previously been explained, in another embodiment a different vaporizer PID temperature controller is employed. In order to establish a repeatable and stable flow, the vaporizer PID temperature controller receives the output of an ionization-type pressure gauge which is typically located in the source housing of commercial ion implanters to monitor the sub-atmospheric pressure in the source housing. Since the pressure gauge output is proportional to the gas flow into the ion source, it output can be employed as the controlling input to the PID temperature controller. The PID temperature controller can subsequently raise or diminish the vaporizer temperature, to increase or decrease gas flow into the source, until the desired gauge pressure is attained. Thus, two useful operating modes of a PID controller are defined: temperature-based, and pressure-based. Referring to FIG. 16B, in another embodiment, these two approaches are uniquely combined such that short-term stability of the flow rate from the vaporizer is accomplished by temperature programming alone, while long-term stability of the flow rate is accomplished by adjusting the vaporizer temperature through software to meet a pressure setpoint which is periodically sampled. The advantage of such a combined approach is that, as the solid feed material is consumed by vaporization, the temperature is slowly raised by software control to compensate for the smaller flow rates realized by the reduced surface area of the material presented to the vaporizer, in accordance with pressure sensed by the pressure gauge in the source housing. In FIG. 16B the ionization gauge 300 which monitors pressure within the ion source housing is the source of an analog pressure signal applied to an analog to digital converter, ADC. The digital output is directed to the CPU which, under software control, evaluates the drift of pressure over time, and introduces a gradual change in temperature setting to stabilize the pressure in its optimal range. In the embodiments of. FIGS. 3 and 3A, temperature of the ionization chamber is controlled by the temperature of the vaporizer. Temperature control for the embodiments of FIGS. 3E, 9B and 18B is achieved by a separate temperature sensing and control unit to control the temperature of the metal heat sink by use of a heat transfer medium or thermoelectric coolers or both. Calculations of Expected Ion Current The levels of ion current production that can be achieved with this new ion source technology are of great interest. Since the ion source uses electron-impact ionization by energetic primary electrons in a well-defined sizeable ionization region defined by the volume occupied by the broad electron beam in traversing the ionization chamber, its ion production efficiency can be calculated within the formalism of atomic physics: I=I0[1−exp{−nls}], (3) where I0 is the incident electron current, I is the electron current affected by a reaction having cross section s, n is the number density of neutral gas molecules within the ionization volume, and l is the path length. This equation can be expressed as follows: f=1−exp{−Lspl}, (4) where f is the fraction of the electron beam effecting ionization of the gas, L is the number density per Torr of the gas molecules at 0° C. (=3.538×1016 Torr−1cm−3), S is the ionization cross section of the specific gas species in cm2, and pl is the pressure-path length product in Torr-cm. The peak non-dissociative ionization cross section of decaborane has not been published, so far as the inventor is aware. However, it should be similar to that of hexane (C6H14), for example, which is known to be about 1.3×1015 cm2. For an ion source extraction aperture 5 cm long and an ionization chamber pressure of 2×10−3 Torr, equation (2) yields f=0.37. This means that under the assumptions of these calculations described below, 37% of the electrons in the electron current produce decaborane ions by single electron collisions with decaborane molecules. The ion current (ions/sec) produced within the ionization volume can be calculated as: Iion=fIel, (5) where Iion is the ion current, and Iel is the electron current traversing the ionization volume. In order to maximize the fraction of ion current extracted from the ion source to form the ion beam, it is important that the profile of the electron beam approximately matches in width the profile of the ion extraction aperture, and that the ions are produced in a region close to the aperture. In addition, the electron current density within the electron beam should be kept low enough so that the probability of multiple ionizations, not taken into account by equations (3) and (4), is not significant. The electron beam current required to generate a beam of decaborane ions can be calculated as: Iel=Iion/f, (6) Given the following assumptions: a) the decaborane ions are produced through single collisions with primary electrons, b) both the gas density and the ion density are low enough so that ion-ion and ion-neutral charge-exchange interactions do not occur to a significant degree, e.g., gas density <1014 cm−3 and ion density <1011 cm−3, respectively, and c) all the ions produced are collected into the beam. For a 1 mA beam of decaborane ions, equation (6) yields Iel=2.7 mA. Since electron beam guns can be constructed to produce electron current densities on the order of 20 mA/cm2, a 2.7 mA electron beam current appears readily achievable with the electron beam gun designs described in this application. The density of primary electrons ne within the ionization volume is given by: ne=Je/eve, (7) where e is the electronic charge (=1.6×10−19 C), and ve is the primary electron velocity. Thus, for a 100 eV, 20 mA electron beam of 1 cm2 cross-sectional area, corresponding to a relatively wide ion extraction aperture as illustrated in FIG. 4F, equation (7) yields ne≈2×1010 cm3. For a narrow extraction aperture, as illustrated in FIG. 5, a 100 eV, 20 mA of 0.4 cm2 cross-sectional area would provide an electron density ne≈5×1010 cm 3. Since the ion density, ni within the ionization volume will likely be of the same order of magnitude as ne, it is reasonable to expect ni<1011 cm−3. It is worth noting that since ne and ni are expected to be of similar magnitude, some degree of charge neutrality is accomplished within the ionization volume due to the ionizing electron beam and ions being of opposite charge. This measure of charge neutrality helps compensate the coulomb forces within the ionization volume, enabling higher values of ne and ni, and reducing charge-exchange interactions between the ions. An important further consideration in determining expected extraction current levels from the broad, collimated electron beam mode is the Child-Langmuir limit, that is, the maximum space charge-limited ion current density which can be utilized by the extraction optics of the ion implanter. Although this limit depends somewhat on the design of the implanter optics, it can usefully be approximated as follows: Jmax=1.72(Q/A)1/2U3/2d−2, (8) where Jmax is in mA/cm2, Q is the ion charge state, A is the ion mass in amu, U is the extraction voltage in kV, and d is the gap width in cm. For B10Hx+ ions at 117 amu extracted at 5 kV from an extraction gap of 6 mm, equation (6) yields Jmax=5 mA/cm2. If we further assume that the area of the ion extraction aperture is 1 cm2, we deduce a Child-Langmuir limit of 5 mA of B10Hx+ ions at 5 keV, which comfortably exceeds the extraction requirements detailed in the above discussion. Ion Extraction Aperture Considerations for the Broad, Aligned Beam Electron Gun Ion Source It is realized, that for the broad electron beam ion source of the present invention, it is possible to employ a larger width ion extraction aperture than typically employed with high current Bernas arc discharge sources. Ion implanter beam lines are designed to image the extraction aperture onto the mass resolving aperture, which is sized to both achieve good transmission efficiency downstream of the mass resolving aperture, and also to maintain a specified mass resolution R (≡M/ΔM, see discussion above). The optics of many high-current beam lines employ unity magnification, so that, in the absence of aberrations, the extent of the ion extraction aperture as imaged onto the resolving aperture is approximately one-to-one, i.e., a mass resolving aperture of the same width as the ion extraction aperture will pass nearly all the beam current of a given mass-to-charge ratio ion transported to it. At low energies, however, space charge forces and stray electromagnetic fields of a Bernas ion source cause both an expansion of the beam as imaged onto the mass resolving aperture, and also a degradation of the mass resolution achieved, by causing significant overlap of adjacent beams of different mass-to-charge ratio ions dispersed by the analyzer magnet. In contrast, in the ion source of the present invention, the absence of a magnetic field in the extraction region, and the lower total ion current level desired, e.g. for decaborane relative say to boron, uniquely cooperate to produce a much improved beam emittance with lower aberrations. For a given mass resolving aperture dimension, this results in higher transmission of the decaborane beam through the mass resolving aperture than one might expect, as well as preserving a higher R. Therefore, the incorporation of a wider ion extraction aperture may not noticeably degrade the performance of the beam optics, or the mass resolution of the implanter. Indeed, with a wider aperture operation of the novel ion source can be enhanced, 1) because of the greater openness of the wider aperture, the extraction field of the extraction electrode will penetrate farther into the ionization volume of the ionization chamber, improving ion extraction efficiency, and 2) it will enable use of a relatively large volume ionization region. These cooperate to improve ion production and reduce the required density of ions within the ionization volume to make the ion source of the invention production worthy in many instances. Care can be taken, however, not to negatively impact the performance of the extraction optics of the implanter. For example, the validity of equation (8) can suffer if the extraction aperture width w is too large relative to the extraction gap d. By adding the preferred constraint that w is generally equal to or less than d, then for the example given above in which d=6 mm, one can use a 6 mm aperture as a means to increase total extracted ion current. For retrofit installations, advantage can also be taken of the fact that many installed ion implanters feature a variable-width mass resolving aperture, which can be employed to open wider the mass resolving aperture to further increase the current of decaborane ions transported to the wafer. Since it has been demonstrated that in many cases it is not necessary to discriminate between the various hydrides of the B10Hx+ ion to accomplish a well-defined shallow p-n junction (since the variation in junction depth created by the range of hydride masses is small compared to the spread in junction location created by boron diffusion during the post-implant anneal), a range of masses may be passed by the resolving aperture to increase ion yield. For example, passing B10H5+ through B10H12+ (approximately 113 amu through 120 amu) in many instances will not have a significant process impact relative to passing a single hydride such as B10H8+, and yet enables higher dose rates. Hence, a mass resolution R of 16 can be employed to accomplish the above example without introducing deleterious effects. Decreasing R through an adjustable resolving aperture can be arranged not to introduce unwanted cross-contamination of the other species (e.g., As and P) which may be present in the ion source, since the mass range while running decaborane is much higher than these species. In the event of operating an ion source whose ionization chamber has been exposed to In (113 and 115 amu), the analyzer magnet can be adjusted to pass higher mass B10Hx+ or even lower mass B9Hx+ molecular ions, in conjunction with a properly sized resolving aperture, to ensure that In is not passed to the wafer. Furthermore, because of the relatively high concentration of the desired ion species of interest in the broad electron beam ion source, and the relatively low concentration of other species that contribute to the total extracted current (reducing beam blow-up), then, though the extracted current may be low in comparison to a Bernas source, a relatively higher percentage of the extracted current can reach the wafer and be implanted as desired. Benefits of Using Hydride Feed Gases, etc. It is recognized that the beam currents obtainable with the broad electron beam ion source described can be maximized by using feed gas species which have large ionization cross sections. Decaborane falls into this category, as do many other hydride gases. While arc plasma-based ion sources, such as the enhanced Bernas source, efficiently dissociate tightly-bound molecular species such as BF3, they tend to decompose hydrides such as decaborane, diborane, germane, and silane as well as trimethyl indium, for example, and generally are not production-worthy with respect to these materials. It is recognized, according to the invention, however that these materials and other hydrides such as phosphene and arsine are materials well-suited to the ion source described here (and do not present the fluorine contamination problems encountered with conventional fluorides). The use of these materials to produce the ion beams for the CMOS applications discussed below, using the ion source principles described, is therefore another important aspect of the present invention. For example, phosphene can be considered. Phosphene has a peak ionization cross section of approximately 5×10−16 cm2. From the calculations above, equation (6) indicates that a broad, collimated electron beam current of 6.2 mA should yield an ion current of 1 mA of AsHx+ ions. The other hydrides and other materials mentioned have ionization cross sections similar to that of phosphene, hence under the above assumptions, the ion source should produce 1 mA for all the species listed above with an electron beam current of less than 7 mA. On the further assumption that the transmission of the implanter is only 50%, the maximum electron beam current required would be 14 mA, which is clearly within the scope of electron beam current available from current technology applied to the specific embodiments presented above. It follows from the preceding discussion that ion currents as high as 2.6 mA can be transported through the implanter using conventional ion implanter technology. According to the invention, for instance, the following implants can be realized using the indicated feed materials in an ion source of the present invention: Low energy boron: vaporized decaborane (B10H14) Medium energy boron: gaseous diborane (B2H6) Arsenic: gaseous arsine (AsH3) Phosphorus: gaseous phosphene (PH3) Indium: vaporized trimethyl indium In(CH3)3 Germanium: gaseous germane (GeH4) Silicon: gaseous silane (SiH4). The following additional solid crystalline forms of In, most of which require lower vaporizer temperatures than can be stably and reliably produced in a conventional ion source vaporizer such as is in common use in ion implantation, can also be used in the vaporizer of the present invention to produce indium-bearing vapor: indium fluoride (InF3), indium bromide (InBr), indium chloride (InCl and InCI3), and indium hydroxide {In(OH)3}. Also, antimony beams may be produced using the temperature-sensitive solids Sb2O5, SbBr3 and SbCl3 in the vaporizer of the present invention. In addition to the use of these materials, the present ion source employing the broad, aligned electron beam in a non-reflex mode of operation can ionize fluorinated gases including BF3, AsF5, PF3, GeF4, and SbF5, at low but sometimes useful atomic ion currents through single ionizing collisions. The ions obtainable may have greater ion purity (due to minimization of multiple collisions), with lessened space charge problems, than that achieved in the higher currents produced by Bernas sources through multiple ionizations. Furthermore, in embodiments of the present invention constructed for multimode operation, all of the foregoing can be achieved in the broad, aligned electron beam mode, without reflex geometry or the presence of a large magnetic confining field, while, by switching to a reflex geometry and employing a suitable magnetic field, a level of arc plasma can be developed to enhance the operation in respect of some of the feed materials that are more difficult to ionize or to obtain higher, albeit less pure, ion currents. To switch between non-reflex and reflex mode, the user can operate controls which switch the beam dump structure from a positive voltage (for broad, aligned electron beam mode) to a negative voltage approaching that of the electron gun, to serve as a repeller (anticathode) while also activating the magnet coils 54. The coils, conventionally, are already present in the implanters originally designed for a Bernas ion source, into which the present ion source can be retrofit. Thus a multi-mode version of the present ion source can be converted to operate with an arc plasma discharge (in the case of a short electron gun in which the emitter is close to the ionization volume as in FIGS. 4A-4D), in a manner similar to a Bernas source of the reflex type, or with a plasma without an active arc discharge if the emitter is remote from the ionization volume. In the embodiment described previously (and also described in FIGS. 18, 18a and 18b) the existing magnet coils can be removed and modified magnet coils provided which are compatible with the geometry of a retrofitted, long, direct-injection electron gun. When these magnet coils are energized, the resultant axial magnetic field can confine the primary electron beam (both within the electron gun and in the ionization chamber) to a narrower cross-section, reducing the spreading of the electron beam profile due to space charge, and increasing the maximum amount of useful electron current which can be injected into the ionization volume. Since the electron emitter of this embodiment is remote from the ionization chamber, it will not initiate an arc discharge, but depending on the strength of the external magnetic field, will provide a low-density plasma within the ionization region. If the plasma density is low enough, multiple ionizations induced by secondary electron collisions with the ions should not be significant; however, the presence of a low-density plasma may enhance the space charge neutrality of the ionization region, enabling higher ion beam currents to be realized. Benefits of Using Dimer-Containing Feed Materials The low-temperature vaporizer of the present invention can advantageously use, in addition to the materials already mentioned, other temperature-sensitive solid source materials which cannot reliably be used in currently available commercial ion sources due to their low melting point, and consequently high vapor pressure at temperatures below 200° C. I have realized that solids which contain dimers of the dopant elements As, In, P, and Sb are useful in the ion source and methods presented here. In some cases, vapors of the temperature-sensitive dimer-containing compounds are utilized in the ionization chamber to produce monomer ions. In other cases, the cracking pattern enables production of dimer ions. Even in the case of dimer-containing oxides, in certain cases, the oxygen can be successfully removed while preserving the dimer structure. Use of dimer implantation from these materials can reap significant improvements to the dose rate of dopants implanted into the target substrates. By extension of equation (8) which quantifies the space charge effects which limit ion extraction from the ion source, the following figure of merit which describes the easing of the limitations introduced by space charge in the case of molecular implantation, relative to monatomic implantation, can be expressed: Δ=n(V1/V2)3/2(m1/m2)−1/2 where a is the relative improvement in dose rate achieved by implanting a molecular compound of mass m1 and containing n atoms of the dopant of interest at an accelerating potential V1, relative to a monatomic implant of an atom of mass m2 at an accelerating potential V2. In the case where V1 is adjusted to give the same implantation depth into the substrate as the monomer implant, equation (9) reduces to Δ=n2. For dimer implantation (e.g., As2 versus As), Δ=4. Thus, up to a fourfold increase in dose rate can be achieved through dimer implantation. Table Ia below lists materials suitable for dimer implantation as applied to the present invention. TABLE Ia Compound Melting Pt (deg C.) Dopant Phase As2O3 315 As2 Solid P2O5 340 P2 Solid B2H6 — B2 Gas In2(SO4)3XH2O 250 In2 Solid Sb2O5 380 Sb2 Solid Where monomer implantation is desired, the same dimer-containing feed material can advantageously be used, by adjusting the mode of operation of the ion source, or the parameters of its operation to sufficiently break down the molecules to produce useful concentrations of monomer ions. Since the materials listed in Table Ia contain a high percentage of the species of interest for doping, a useful beam current of monomer dopant ions can be obtained. Use of the Ion Source in CMOS Ion Implant Applications In present practice, ion implantation is utilized in many of the process steps to manufacture CMOS devices, both in leading edge and traditional CMOS device architectures. FIG. 17 illustrates a generic CMOS architecture and labels traditional implant applications used in fabricating features of the transistor structures (from R. Simonton and F. Sinclair, Applications in CMOS Process Technology, in Handbook of Ion Implantation Technology, J. F. Ziegler, Editor, North-Holland, N.Y., 1992). The implants corresponding to these labeled structures are listed in Table I below, showing the typical dopant species, ion energy, and dose requirements which the industry expects to be in production in 2001. TABLE I Energy Label Implant Specie (keV) Dose (cm−2) A NMOS source/drain As 30-50 1e15-5e15 B NMOS threshold adjust (Vt) P 20-80 2e12-1e13 C NMOS LDD or drain P 20-50 1e14-8e14 extension D p-well (tub) structure B 100-300 1e13-1e14 E p-type channel stop B 2.0-6 2e13-6e13 F PMOS source/drain B 2.0-8 1e15-6e15 G PMOS buried-channel Vt B 10-30 2e12-1e13 H PMOS punchthrough P 50-100 2e12-1e13 suppression I n-well (tub) structure P 300-500 1e13-5e13 J n-type channel stop As 40-80 2e13-6e13 K NMOS punchthrough B 20-50 5e12-2e13 suppression L PMOS LDD or drain B 0.5-5 1e14-8e14 extension M Polysilicon gate doping As, B 2.0-20 2e15-8e15 In addition to the implants listed in Table I, recent process developments include use of C implants for gettering, use of Ge or Si for damage implants to reduce channeling, and use of medium-current In and Sb. It is clear from Table I that, apart from creating the source/drains and extensions, and doping the polysilicon gate, all other implants require only low or medium-dose implants, i.e. doses between 2×1012 and 1×1014 cm−2. Since the ion current required to meet a specific wafer throughput scales with the desired implanted dose, it seems clear that these low and medium-dose implants can be performed with the broad, aligned electron beam ion source of the present invention at high wafer throughput with ion beam currents below 1 mA of P, As, and B. Further, of course, the decaborane ion currents achievable according to the present invention should enable producing the p-type source/drains and extensions, as well as p-type doping of the polysilicon gates. It is therefore believed that the broad, aligned electron beam ion source described above enables high wafer throughputs in the vast majority of traditional ion implantation applications by providing a beam current of 1 mA of B10H14, As, P, and B or B2. The addition of Ge, Si, Sb, and In beams in this current range, also achievable with the present invention, will enable more recent implant applications not listed in Table I. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention The invention provides production-worthy ion sources and methods capable of using new source materials, in particular, heat-sensitive materials such as decaborane (B 10 H 14 ), and hydrides and dimer-containing compounds novel to the ion implantation process, to achieve new ranges of performance in the commercial ion implantation of semiconductor wafers. The invention enables shallower, smaller and higher densities of semiconductor devices to be manufactured, particularly in Complementary Metal-Oxide Semiconductor (CMOS) manufacturing. In addition to enabling greatly enhanced operation of new ion implanter equipment in the manufacture of semiconductor devices, the invention enables the new ion source to be retrofit into the existing fleet of ion implanters with great capital cost savings. Embodiments of the invention uniquely implant decaborane and the other dopant materials in particularly pure ion beams, enabling a wide range of the needs of a fabrication facility to be met. Various novel constructional, operational and process features that contribute to the cost-effectiveness of the new technology are applicable as well to prior technology of the industry. 2. Description of the Prior Art As is well known, ion implantation is a key technology in the manufacture of integrated circuits (ICs). In the manufacture of logic and memory ICs, ions are implanted into silicon or GaAs wafers to form transistor junctions, and to dope the well regions of the p-n junctions. By selectively controlling the energy of the ions, their implantation depth into the target wafer can be selectively controlled, allowing three-dimensional control of the dopant concentrations introduced by ion implantation. The dopant concentrations control the electrical properties of the transistors, and hence the performance of the ICs. A number of dopant feed materials have previously been used, including As, Ar, B, Be, C, Ga, Ge, In, N, P, Sb and Si. For those species which are of solid elemental form, many are obtainable in gaseous molecular form, such as fluoride compounds that are ionizable in large quantities at significantly elevated temperatures. The ion implanter is a manufacturing tool which ionizes the dopant-containing feed materials, extracts the dopant ions of interest, accelerates the dopant ions to the desired energy, filters away undesired ionic species, and then transports the dopant ions of interest to the wafer at the appropriate energy for impact upon the wafer. The presence in the implanter of certain elements, such as the disassociated element fluorine, is detrimental to the implanted wafers, but, despite such drawbacks, trace amounts of such contaminants have been tolerated in many contexts, in the interest of achieving production-worthy throughput volume. Lower contaminant levels from what is now achievable is desired. In a complex relationship, overall, a number of variables must be controlled in order to achieve a desired implantation profile for a given ion implantation process: The nature of the dopant feed material (e.g., BF 3 gas) Dopant ion species (e.g., B + ) Ion energy (e.g., 5 keV) Chemical purity of the ion beam (e.g., <0.01% energetic contaminants) Isotopic purity of the ion beam (e.g., ability to discriminate between 113 In and 115 In) Energy purity of the ion beam (e.g., <2% full width at half maximum, i.e. FWHM) Angular divergence and spatial extent of the beam on the wafer Total dose (e.g., 10 15 atoms/cm 2 ) implanted on the wafer Uniformity of the dose (e.g., ±1% variation in the implanted density over the total wafer surface area). These variables affect the electrical performance, minimum manufacturable size and maximum manufacturable density of transistors and other devices fabricated through ion implantation. A typical commercial ion implanter is shown in schematic in FIG. 1 . The ion beam I is shown propagating from the ion source 42 through a transport (i.e. “analyzer”) magnet 43 , where it is separated along the dispersive (lateral) plane according to the mass-to-charge ratio of the ions. A portion of the beam is focused by the magnet 43 onto a mass resolving aperture 44 . The aperture size (lateral dimension) determines which mass-to-charge ratio ion passes downstream, to ultimately impact the target wafer 55 , which typically may be mounted on a spinning disk 45 . The smaller the mass resolving aperture 44 , the higher the resolving power R of the implanter, where R=M/ΔM (M being the nominal mass-to-charge ratio of the ion and ΔM being the range of mass-to-charge ratios passed by the aperture 44 ). The beam current passing aperture 44 can be monitored by a moveable Faraday detector 46 , whereas a portion of the beam current reaching the wafer position can be monitored by a second Faraday detector 47 located behind the disk 45 . The ion source 42 is biased to high voltage and receives gas distribution and power through feedthroughs 48 . The source housing 49 is kept at high vacuum by source pump 50 , while the downstream portion of the implanter is likewise kept at high vacuum by chamber pump 51 . The ion source 42 is electrically isolated from the source housing 49 by dielectric bushing 52 . The ion beam is extracted from the ion source 42 and accelerated by an extraction electrode 53 . In the simplest case (where the source housing 49 , implanter magnet 43 , and disk 45 are maintained at ground potential), the final electrode of the extraction electrode 53 is at ground potential and the ion source is floated to a positive voltage V a , where the beam energy E=qV a and q is the electric charge per ion. In this case, the ion beam impacts the wafer 55 with ion energy E. In other implanters, as in serial implanters, the ion beam is scanned across a wafer by an electrostatic or electromagnetic scanner, with either a mechanical scan system to move the wafer or another such electrostatic or electromagnetic scanner being employed to accomplish scanning in the orthogonal direction. A part of the system of great importance in the technology of ion implantation is the ion source. FIG. 2 shows diagrammatically the “standard” technology for commercial ion sources, namely the “Enhanced Bernas” arc discharge ion source. This type of source is commonly the basis for design of various ion implanters, including high current, high energy, and medium current ion implanters. The ion source a is mounted to the vacuum system of the ion implanter through a mounting flange b which also accommodates vacuum feedthroughs for cooling water, thermocouples, dopant gas feed, N 2 cooling gas, and power. The dopant gas feed c feeds gas, such as the fluorides of a number of the desired dopant species, into the arc chamber d in which the gas is ionized. Also provided are dual vaporizer ovens e, f inside of the mounting flange in which solid feed materials such as As, Sb 2 O 3 , and P may be vaporized. The ovens, gas feed, and cooling lines are contained within a water cooled machined aluminum block g. The water cooling limits the temperature excursion of the aluminum block g while the vaporizers, which operate between 100° C. and 800° C., are active, and also counteracts radiative heating by the arc chamber d when the ion source is active. The arc chamber d is mounted to, but designedly is in poor thermal contact with, the aluminum block g. The ion source a employs an arc discharge plasma, which means that it operates by sustaining within a defined chamber volume a generally narrow continuous electric arc discharge between hot filament cathode h, residing within the arc chamber d, and the internal walls of the arc chamber d. The arc produces a narrow hot plasma comprising a cloud of primary and secondary electrons interspersed with ions of the gas that is present. Since this arc can typically dissipate in excess of 300 W energy, and since the arc chamber d cools only through radiation, the arc chamber in such Bernas ion sources can reach a temperature of 800° C. during operation. The gas is introduced to arc chamber d through a low conductance passage and is ionized through electron impact with the electrons discharged between the cathode h and the arc chamber d and, as well, by the many secondary electrons produced by the arc discharge. To increase ionization efficiency, a substantial, uniform magnetic field i is established along the axis joining the cathode h and an anticathode j by externally located magnet coils, 54 as shown in FIG. 1 . This provides confinement of the arc electrons, and extends the length of their paths. The anticathode j (sometimes referred to as a “repeller”) located within the arc chamber d but at the end opposite the cathode h is typically held at the same electric potential as the cathode h, and serves to reflect the arc electrons confined by the magnetic field i back toward the cathode h, from which they are repelled back again, the electrons traveling repeatedly in helical paths. The trajectory of the thus-confined electrons results in a cylindrical plasma column between the cathode h and anticathode j. The arc plasma density within the plasma column is typically high, on the order of 10 12 per cubic centimeter; this enables further ionizations of the neutral and ionized components within the plasma column by charge-exchange interactions, and also allows for the production of a high current density of extracted ions. The ion source a is held at a potential above ground (i.e., above the potential of the wafer 55 ) equal to the accelerating voltage V a of the ion implanter: the energy, E, of the ions as they impact the wafer substrate is given by E=qV a , where q is the electric charge per ion. The cathode h of such a conventional Bernas arc discharge ion source is typically a hot filament or an indirectly-heated cathode which thermionically emits electrons when heated by an external power supply. It and the anticathode are typically held at a voltage V c between 60V and 150V below the potential of the ion source body V a . Once an arc discharge plasma is initiated, the plasma develops a sheath adjacent the exposed surface of the cathode h within chamber d. This sheath provides a high electric field to efficiently extract the thermionic electron current for the arc; high discharge currents (e.g., up to 7 A) can be obtained by this method. The discharge power P dissipated in the arc chamber is P=DV c , typically hundreds of watts. In addition to the heat dissipated by the arc, the hot cathode h also transfers power to the walls of the arc chamber d. Thus, the arc chamber d provides a high temperature environment for the dopant arc plasma, which boosts ionization efficiency relative to a cold environment by increasing the gas pressure within the arc chamber d, and by preventing substantial condensation of dopant material on the hot chamber walls. If the solid source vaporizer ovens e or f of the Bernas arc discharge ion source are used, the vaporized material feeds into the arc chamber d with substantial pressure drop through narrow vaporizer feeds k and l, and into plenums m and n. The plenums serve to diffuse the vaporized material into the arc chamber d, and are at about the same temperature as the arc chamber d. Radiative thermal loading of the vaporizers by the arc chamber also typically prevents the vaporizers from providing a stable temperature environment for the solid feed materials contained therein below about 200° C. Thus, typically, only solid dopant feed materials that both vaporize at temperatures >200° C. and decompose at temperatures >800° C. (the temperature of the walls of the ionization chamber of a typical Bernas source) can be successfully vaporized and introduced by this method. A very significant problem which currently exists in the ion implantation of semiconductors is the limitation of production-worthy ion implantation implanters that prevents effective implanting of dopant species at low (e.g., sub-keV) energies at commercially desired rates. One critically important application which utilizes low-energy dopant beams is the formation of shallow transistor junctions in CMOS manufacturing. As transistors shrink in size to accommodate more transistors per IC according to a vital trend, the transistors must be formed closer to the surface of the target wafer. This requires reducing the velocity, and hence the energy, of the implanted ions, so that they deposit at the desired shallow level. The most critical need in this regard is the implantation of low-energy boron, a p-type dopant, into silicon wafers. Since boron atoms have low mass, at a given energy for which the implanter is designed to operate, they must have higher velocity and will penetrate deeper into the target wafer than other p-type dopants; therefore there is a need for boron to be implanted at lower energies than other species. Ion implanters are relatively inefficient at transporting low-energy ion beams due to space charge within the ion beam, the lower the energy, the greater the problem. The space charge in low energy beams causes the beam cross-section area (i.e. its “profile”) to grow larger as the ions proceed along the beam line (there is “beam blow-up”). When the beam profile exceeds the profile for which the implanter's transport optics have been designed, beam loss through vignetting occurs. For example, at 500 eV transport energy, many ion implanters currently in use cannot transport enough boron beam current to be commercially efficient in manufacturing; i.e., the wafer throughput is too low because of low implantation dose rate. In addition, known ion sources rely on the application of a strong magnetic field in the source region. Since this magnetic field also exists to some extent in the beam extraction region of the implanter, it tends to deflect such a low-energy beam and substantially degrade the emittance properties of the beam, which further can reduce beam transmission through the implanter. An approach has been proposed to solve the problem of low-energy boron implantation: molecular beam ion implantation. Instead of implanting an ion current I of atomic B + ions at an energy E, a decaborane molecular ion, B 10 H x + , is implanted at an energy 10 ×E and an ion current of 0.10×I. The resulting implantation depth and dopant concentration (dose) of the two methods have been shown to be generally equivalent, with the decaborane implantation technique, however, having significant potential advantages. Since the transport energy of the decaborane ion is ten times that of the dose-equivalent boron ion, and the ion current is one-tenth that of the boron current, the space charge forces responsible for beam blowup and the resulting beam loss can potentially be much reduced relative to monatomic boron implantation. While BF 3 gas can be used by conventional ion sources to generate B + ions, decaborane (B 10 H 14 ) must be used to generate the decaborane ion B 10 H x + . Decaborane is a solid material which has a significant vapor pressure, on the order of 1 Torr at 20° C., melts at 100° C., and decomposes at 350° C. To be vaporized through preferred sublimination, it must therefore be vaporized below 100° C., and it must operate in a production-worthy ion source whose local environment (walls of the ionization chamber and components contained within the chamber) is below 350° C. to avoid decomposition. In addition, since the B 10 H 14 molecule is so large, it can easily disassociate (fragment) into smaller components, such as elemental boron or diborane (B 2 H 6 ), when subject to charge-exchange interactions within an arc discharge plasma, hence it is recognized that conventionally operated Bernas arc plasma sources can not be employed in commercial production, and that ionization should be obtained primarily by impact of primary electrons. Also, the vaporizers of current ion sources cannot operate reliably at the low temperatures required for decaborane, due to radiative heating from the hot ion source to the vaporizer that causes thermal instability of the molecules. The vaporizer feed lines k, l can easily become clogged with boron deposits from decomposed vapor as the decaborane vapor interacts with their hot surfaces. Hence, the present production-worthy implanter ion sources are incompatible with decaborane ion implantation. Prior efforts to provide a specialized decaborane ion source have not met the many requirements of production-worthy usage. More broadly, there are numerous ways in which technology that has been common to the industry has had room for improvement. Cost-effective features, presented here as useful in implementing the new technology, are applicable to implementation of the established technology as well. | <SOH> SUMMARY OF THE INVENTION <EOH>Various aspects of the invention provide improved approaches and methods for efficiently: Vaporizing decaborane and other heat-sensitive materials via a novel vaporizer and vapor delivery system; Delivering a controlled, low-pressure drop flow of vapors, e.g. decaborane, into the ion source; Ionizing the decaborane into a large fraction of B 10 H x + ; Preventing thermal dissociation of decaborane; Limiting charge-exchange and low energy electron-induced fragmentation of B 10 H x + ; Operating the ion source without an arc plasma, which can improve the emittance properties and the purity of the beam; Operating the ion source without use of a strong applied magnetic field, which can improve the emittance properties of the beam; Using a novel approach to produce electron impact ionizations without the use of an arc discharge, by incorporation of an externally generated, broad directional electron beam which is aligned to pass through the ionization chamber to a thermally isolated beam dump; Providing production-worthy dosage rates of boron dopant at the wafer; Providing a hardware design that enables use also with other dopants, especially using novel hydride, dimer-containing, and indium- or antimony-containing temperature-sensitive starting materials, to further enhance the economics of use and production worthiness of the novel source design and in many cases, reducing the presence of contaminants; Matching the ion optics requirements of the installed base of ion implanters in the field; Eliminating the ion source as a source of transition metals contamination, by using an external and preferably remote cathode and providing an ionization chamber and extraction aperture fabricated of non-contaminating material, e.g. graphite, silicon carbide or aluminum; Enabling retrofit of the new ion source into the ion source design space of existing Bernas source-based ion implanters and the like or otherwise enabling compatibility with other ion source designs; Using a control system in retrofit installations that enables retention of the installed operator interface and control techniques with which operators are already familiar; Enabling convenient handling and replenishment of the solid within the vaporizer without substantial down-time of the implanter; Providing internal adjustment and control techniques that enable, with a single design, matching the dimensions and intensity of the zone in which ionization occurs to the beam line of the implanter and the requirement of the process at hand; Providing novel approaches, starting materials and conditions of operation that enable the making of future generations of semiconductor devices and especially CMOS source/drains and extensions, and doping of silicon gates; And generally, providing features, relationships and methods that achieve production-worthy ionization of decaborane and numerous other dopant feed materials many of which are novel to ion implantation, to meet the practical needs of fabrication facilities. Embodiments of the present invention can enhance greatly the capability of new ion implantation systems and can provide a seamless and transparent upgrade to end-users' existing implanters. In particular, aspects of the invention are compatible with current ion implantation technology, such that an ion source constructed according to the invention can be retrofitted into the existing fleet of ion implanters currently installed in expensive fabrication plants. Embodiments of the invention are (1) constructed, sized and arranged such that they fit into the existing ion source space of commercial implanters, and 2) employ a novel control system for the ion source which can physically replace the existing ion source controller, without further modification of the implanter controls and qualified production techniques. According to one aspect of the invention, an ion source capable of providing ions in commercial ion current levels to the ion extraction system of an ion implanter is provided, the ion source comprising an ionization chamber defined by walls enclosing an ionization volume, there being an ion extraction aperture in a side wall of the ionization chamber, the aperture having a length and width sized and arranged to enable the ion current to be extracted from the ionization volume by the extraction system. The invention features a broad beam electron gun constructed, sized and arranged with respect to the ionization chamber to direct an aligned beam of primary electrons through the ionization chamber to a beam dump maintained at a substantial positive voltage relative to the emitter voltage of the electron beam gun. Preferably the beam dump is thermally isolated from the ionization chamber or separately cooled. The axis of the beam path of the primary electrons extends in a direction generally adjacent to the aperture, the electron beam having a dimension in the direction corresponding to the direction of the width of the extraction aperture that is about the same as or larger than the width of the aperture, a vaporizer arranged to introduce e.g. decaborane vapor to the ionization volume, and a control system enables control of the energy of the primary electrons so that individual vapor molecules can be ionized principally by collisions with primary electrons from the electron gun. In preferred embodiments the electron gun is mounted on a support that is thermally isolated from the walls of the ionization chamber. According to another aspect of the invention, an ion source capable of providing ions of decaborane in commercial ion current levels to the ion extraction system of an ion implanter is provided, the ion source comprising an ionization chamber defined by walls enclosing an ionization volume, there being an ion extraction aperture in a side wall of the ionization chamber, arranged to enable the ion current to be extracted from the ionization volume by an extraction system, an electron gun mounted on a support that is outside of and thermally isolated from the walls of the ionization chamber, and constructed, sized and arranged with respect to the ionization chamber to direct a broad beam of primary electrons through the ionization chamber to a beam dump maintained at a substantial positive voltage relative to the emitter voltage of the electron beam gun, the beam dump being located outside of, and thermally isolated from, the ionization chamber, the beam path of the primary electrons extending in a direction adjacent to the ion extraction aperture, a passage arranged to introduce vapor or gas of a selected material to the ionization volume, and a control system enabling control of the energy of the primary electrons so that the material can be ionized. According to another aspect of the invention, an ion source capable of providing ions in commercial ion current levels to the ion extraction system of an ion implanter is provided, the ion source comprising an ionization chamber defined by walls enclosing an ionization volume, there being an extraction aperture in a side wall of the ionization chamber that is arranged to enable the ion current to be extracted from the ionization volume by the extraction system, an electron gun mounted on a support that is outside of and thermally isolated from the walls of the ionization chamber, and constructed, sized and arranged with respect to the ionization chamber to direct a broad beam of primary electrons through the ionization chamber to a beam dump maintained at a substantial positive voltage relative to the emitter voltage of the electron beam gun, the electron beam gun comprising a heated electron emitting surface of predetermined size followed by electron optical elements that enlarge the beam in the ionization chamber relative to the size of the emitting surface of the electron gun, the beam path of the primary electrons extending in a direction adjacent to the ion extraction aperture, a passage arranged to introduce vapor or gas of a selected material to the ionization volume, and a control system enabling control of the energy of the primary electrons so that the material can be ionized. Preferred embodiments of these and other aspects of the invention have one or more of the following features: A vaporizer is incorporated into the ion source assembly in close proximity to the ionization chamber and communicating with it through a high conductance, preferably along a line of sight path, and is constructed to be controllable over part or all of the range of 20° C. to 200° C. The beam dump has an electron-receiving surface larger than the cross-section of the electron beam entering the ionization chamber. The electron gun produces a generally collimated beam, in many instances, preferably the electron gun being generally collimated while transiting the ionization chamber. The beam dump is mounted on a dynamically cooled support, preferably a water-cooled support. The electron gun is mounted on a dynamically cooled support, preferably, a water-cooled support. The electron gun cathode is disposed in a position remote from the ionization chamber. The volume occupied by the electron gun cathode is evacuated by a dedicated vacuum pump. The ion source electron gun includes a cathode and variable electron optics that shape the flow of electrons into a beam of selected parameters, including a general dispersion of the electrons, and a profile matched to the extraction aperture, preferably in many cases the electrons being in a collimated beam within the ionization chamber. The electron gun comprises a high transmission electron extraction stage capable of extracting at least the majority of electrons from an emitter of the gun, the extraction stage followed by a collimator and further electron optic elements, in preferred embodiments the further electron optics comprising an electron zoom lens or electron optics constructed to have the capability to vary the energy and at least one magnification parameter of the electron beam, preferably both linear and angular magnification of the beam and in preferred embodiments the electron optics comprising a five or more element zoom lens. The ion source is constructed, sized and arranged to be retrofit into a pre-existing ion implanter, into the general space occupied by the original ion source for which the implanter was designed. The ion source is constructed and arranged to cause the electron beam to have a profile matched to the opening of the ion extraction aperture, preferably the cross-section being generally rectangular. The electron beam gun of the ion source is an elongated electron gun, in certain embodiments the length of the gun being longer than the length of the ionization path length in the ionization chamber, preferably, e.g. for retrofit installations, the principal direction of the elongated electron gun being arranged generally parallel to the direction in which the ion beam is extracted from the ionization chamber, and an electron mirror is arranged to divert the electron beam to a transverse direction to pass through the ionization volume. In this and other embodiments, preferably the cathode of the elongated electron beam gun is a uniform emitting surface sized smaller than the maximum cross-section of the electron beam passing through the ionization chamber, and the electron optics include optics arranged to expand the electron beam before it enters the ionization chamber. In various embodiments some of the optics precede the mirror or are downstream of the mirror, and the optics are constructed to vary angular as well as linear magnification. Preferably these optics comprise a zoom control to enable variation of the electron energy of the beam. The control system includes a circuit for measuring the current and the intensity of the beam dump. The ion source electron beam gun is constructed to operate with a voltage drop relative to the walls of the ionization chamber between about 20 and 300 or 500 electron volts; preferably, to ionize decaborane, the voltage drop being between 20 and 150 electron volts, higher voltages being useful for providing double charges on selected implant species or for providing ionizing conditions for other feed materials. For use with a previously existing ion implanter designed for use with a Bernas arc discharge source having a directly or indirectly heated cathode; the control system includes an operator control screen corresponding to the screen used for the Bernas source, and a translator effectively translates arc current control signals to control signals for the electron gun. The ionization chamber is in thermal continuity with the vaporizer, or with a temperature control device. The vaporizer for decaborane includes a temperature control system, and the ionization chamber is in thermal continuity with the vaporizer, preferably the ionization chamber is defined within a conductive block defining a heat sink that is in thermal continuity with the vaporizer, preferably, the conductive block being in thermal continuity with the vaporizer via one or more conductive gaskets, including a gasket at which the vaporizer may be separated from the remainder of the assembly. The ionization chamber is defined by a removable block disposed in heat transfer relationship to a temperature controlled mounting block, preferably the removable block comprised of graphite, silicon carbide or aluminum. The ion source includes a mounting flange for joining the ion source to the housing of an ion implanter, the ionization chamber being located on the inside of the mounting flange and the vaporizer being removably mounted to the exterior of the mounting flange via at least one isolation valve which is separable from the mounting flange with the vaporizer, enabling the vaporizer charge volume to be isolated by the valve in closed position during handling, preferably there being two isolation valves in series, one unified with and transportable with a removed vaporizer unit, and one constructed to remain with and isolate the remainder of the ion source from the atmosphere. In certain preferred embodiments, two such vaporizers are provided, enabling one to be absent, while being charged or serviced, while the other operates, or enabling two different materials to be vaporized without maintenance of the ion source, or enabling additional quantities of the same materials to be present to enable a protracted implant run. Opposite walls of the ionization chamber corresponding respectively to the electron beam gun and the beam dump have ports through which electrons pass enroute from the electron beam gun to the beam dump, the spaces in the vicinity of the ports being surrounded by housing and communicating with a vacuum system. The ion source includes a gas inlet via into which compounds such as arsine, phosphene, germane and silane gas can be introduced to the ionization chamber for ionization. The extraction aperture of the ionization chamber, for e.g. high current machines, is about 50 mm or more in length and at least about 3.5 mm in width, and the transverse cross sectional area of the electron beam is at least about 30 square mm, preferably, e.g. for decaborane in high current machines, the cross-sectional area of the beam being at least about 60 square mm. For a medium current ion implanter preferably the extraction aperture is at least 15 mm in length and at least about 1.5 mm in width, and the transverse cross sectional area of the electron beam is at least about 15 square millimeters. In many medium current implanters, the extraction aperture can be sized 20 mm long by 2 mm wide, in which case the cross-sectional area of the electron beam can be reduced to a minimum of about 20 square mm. An ion implantation system is provided comprising an ion implanter designed for a first ion source occupying a general design volume, and a second ion source of any of the novel types described above is operatively installed in that volume, preferably the electron gun being of elongated form, having its principal direction arranged parallel to the direction the ion beam is extracted from the ionization chamber, and an electron mirror is arranged to divert the electron beam to a transverse direction to pass through the ionization volume. In this and other embodiments of an ion implantation system, preferably the cathode is sized smaller than the maximum cross-section of the electron beam passing through the ionization chamber, and the electron optics include optics arranged to expand the electron beam before it enters the ionization chamber, preferably these optics being associated with a zoom control to enable controlled variation of the electron energy. The invention also features methods of employing apparatus having the various features described to ionize decaborane, the mentioned hydrides and other temperature-sensitive materials including indium-, antimony-, and dimer-containing compounds. The methods include using the various methods of control that are described in the preceding description and in the following text. In particular, the invention includes the methods described of generating the electron beam, accelerating and collimating the beam, controlling its transverse profile and its energy, and causing it to transit the ionization chamber to create the desired ions while keeping the ionization chamber cool. It also includes the methods of vaporizing the solid materials and cooling the ionization chamber with the vaporizer heat control system as well as controlling the vapor production of the vaporizer by pressure control or by a dual temperature and pressure control that is for instance capable of adjusting for the decreasing volume of the feed material as operation proceeds. Particular aspects of the invention feature methods of providing ions during ion implantation comprising introducing material comprising a gas or heated vapor to a chamber enclosing an ionization volume, the chamber having an extraction aperture, and passing through the ionization volume adjacent the aperture a broad beam of electrons. According to one aspect of the invention, the broad beam is aligned with a beam dump that is thermally isolated from the chamber, the energy of the electrons being selected to ionize the material. According to another aspect, the energy and magnification of the electron beam are controlled with electron zoom optics to ionize the material. According to another aspect, the beam is formed and the energy of the electrons is controlled by successively accelerating and decelerating the electrons. In preferred embodiments of these aspects the broad electron beam is emitted from a heated emitter surface that is remote from and thermally isolated from the ionization chamber; electrons from an emitter surface are accelerated, collimated and passed through beam-expanding optics before passing through the ionization chamber, and, for vaporizing decaborane, the method includes introducing the decaborane vapors to the ionization chamber, and controlling the broad electron beam parameters to ionize the decaborane and produce a decaborane current, or the method includes introducing to the ionization chamber a hydride of a desired species, and ionizing the hydride, in preferred embodiments the hydride being arsine or phosphene or germane or silane or diborane. In other preferred methods, an indium-containing compound is employed including introducing the indium compound vapors to the ionization chamber, and controlling the broad electron beam parameters to ionize the indium compound and produce an indium ion current, preferably the compound being trimethyl indium. In still other preferred methods, a compound containing antimony is employed including introducing the antimony compound vapors to the ionization chamber, and controlling the broad electron beam parameters to ionize the antimony compound and produce an antimony ion current, preferably the compound being antimony oxide (Sb 2 O 5 ). Other dimer-containing compounds described below are also useful, both for producing dimer ions and monomer ions. In the various methods preferably a beam dump is employed to receive the electron beam after it transits the ionization volume, including maintaining the beam dump thermally isolated from the chamber and at a voltage potential at least as high as that of the chamber. In some instances a magnetic field is applied to constrain the electron beam, e.g. to counteract space-charge effects. In some instances, for certain compounds, preferably the process described is converted to a reflex ionization mode by changing the potential of the beam dump to a substantially lower potential than the walls of the ionization chamber to act as an electron-repelling anticathode, in certain cases the method including applying a magnetic field parallel to the electron beam, or continuing to cool the walls of the ionization chamber while operating in reflex mode. The invention also features the methods of retrofitting the new ion source into the existing fleet of ion implanters, and of controlling the ion source by means of the operator interface of the arc plasma ion source that it replaces. Also, the invention features methods of conducting entire ion implantation processes using the equipment and controls described to form semiconductor devices, in particular shallow source/drains and extensions, and doping of the silicon gates in CMOS fabrication. In addition, the invention features methods and apparatus for dual mode operation, both a broad E-Beam mode with the beam aligned with a beam dump at positive potential and a reflex mode, in which the dump is converted to a repeller (anticathode) with optional use of a confining magnetic field, advantageously both conducted with cooled walls to ionize materials such as hydrides that disassociate with elevated temperatures. In the method employing a broad electron beam directed to a beam dump, in certain cases the invention features applying a magnetic field to constrain the electron beam. According to another aspect of the invention, an ion source is provided having a member whose surface is exposed to contact of a dopant feed material, including gases, vapors or ions thereof, the relationship of the contact being such that condensation or molecular dissociation will occur if the temperature of the surface of the member is not within a desired operational range, the member being disposed in conductive heat transfer relationship with a second member, the temperature of which is actively controlled. The temperature of the second member can be determined by water-cooling the member with de-ionized water of a given temperature. The second member can be associated with a thermoelectric cooling unit associated with a control system that can activate the unit to maintain the temperature of the surface within said operational range. In some cases a heater element is included which is arranged to cooperate with the cooling unit to maintain the second member at a temperature. In certain embodiments the cooling unit has a surface which forms a thermally conductive interface with an opposed surface of the member. In certain preferred embodiments a conductive gas fills gaps at an interface in the conductive path under conditions in which the gas molecules act to transfer heat across the interface by conduction, preferably the conductive gas being fed into channels formed in at least one of the surfaces across which the thermal heat conduction is to occur. The invention also features a control system for the vaporizer which includes an ionization gauge sensitive to a pressure related to a pressure within the ionization chamber. Another aspect of the invention is an ion source which includes an accel-decel electron gun arranged to project a beam of electrons through an ionization chamber to ionize gas or vapors in a region adjacent an extraction aperture. Preferred embodiments of this aspect have one or more of the following features: A magnetic coil is disposed outside of the ionization chamber, the electron gun is mounted concentrically with the coil, such that the emission axis of the electron gun is aligned to emit electrons into the ionization chamber and the coil, when energized, provides a magnetic field which limits space charge expansion of the electron beam as it transits the ionization chamber. The volume occupied by the electron gun cathode is evacuated by a dedicated vacuum pump. A beam dump at a positive voltage is aligned to receive electrons of the beam that transit the ionization chamber. This accel-decel electron gun is disposed outside of an ionization chamber, the electron gun mounted such that the emission axis of the electron gun is aligned to emit electrons into the ionization chamber. The accel-decel gun has an electron zoom lens. The accel-decel gun is comprised of a high-transmission extraction stage followed by a focusing lens having at least two elements followed by a relatively short, strongly-focusing lens which acts to decelerate the electron beam entering the ionization chamber, preferably the short lens being a multi-aperture lens comprising a series of at least two conducting plates each having an aperture, the voltage on the plates being of respectively decreasing values to decelerate the electrons. The beam deceleration stage of the electron gun focuses the beam in the ionization chamber at a point near mid-length of an elongated aperture, past which the electron beam passes. Other aspects and detailed features of the invention will be apparent from the drawings, the following description of preferred embodiments, and from the claims and abstract. | 20040708 | 20070306 | 20050310 | 94315.0 | 0 | A, MINH D | ION IMPLANTATION ION SOURCE, SYSTEM AND METHOD | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,887,569 | ACCEPTED | Mill blank library and computer-implemented method for efficient selection of blanks to satisfy given criteria | The present invention relates generally to mill blank constructions to facilitate the manufacture of dental restorations. A given mill blank is formed in a shape (i.e. with a given geometry) that has been predetermined to reduce material waste when the mill blank is machined into the final part. A set of two or more blanks each having such characteristics comprise a smart blank “library.” In one embodiment, a smart blank library includes a sufficient number of unique blanks such that, when the geometry of the designed restoration is known, the smart blank with a highest yield can be selected for use in milling the restoration. The “yield” of a given smart blank represents the amount of material of the smart blank that is actually used in the final restoration. Automated processes for smart blank inventory management and smart blank selection are also described. | 1. A method of assembling blanks for use in manufacturing dental restorations, comprising: given a set of blanks, selecting an assemblage of the blanks that satisfy a given criterion, wherein at least first and second of the blanks in the assemblage comprise a body adapted to be shaped by material removal, the body of the first blank having a geometry that differs from the body of the second blank by other than scaling; and using that assemblage to manufacture dental restorations. 2. The method as described in claim 1 wherein the given criterion is that an average yield per blank in the assemblage is maximized. 3. The method as described in claim 1 wherein the given criterion is that a weighted average of the blank yields in the assemblage is maximized. 4. The method as described in claim 1 wherein the given criterion balances an average yield per blank with a given productivity factor. 5. The method as described in claim 1 wherein the given criterion balances an average yield per blank with a given cost factor. 6. The method as described in claim 1 wherein the given criterion balances among a set of yield, productivity, cost and tooth distribution factors. 7. The method as described in claim 1 further including the step of maintaining the assemblage over a given time period. 8. An assemblage, comprising: a plurality of mill blanks, at least first and second of the mill blanks in the plurality each comprising a body adapted to be shaped by material removal; wherein the body of the first blank has a geometry that differs from the body of the second blank by other than scaling. 9. The assemblage as described in claim 8 wherein each blank includes a holder to enable the blank to be maintained within a shaping apparatus. 10. The assemblage as described in claim 8 wherein at least one of the blanks is formed of a precious metal or precious metal alloy. 11. The assemblage as described in claim 8 wherein at least one of the blanks is formed of a semi-precious metal or semi-precious metal alloy. 12. The assemblage as described in claim 8 wherein at least one of the blanks is formed of a ceramic. 13. The assemblage as described in claim 8 wherein the body of at least one of the blanks has at most one symmetric plane. 14. A method of producing dental items, comprising: maintaining an assemblage of “m” mill blanks, the assemblage comprising at least first and second mill blanks each comprising a body adapted to be shaped by material removal, wherein the body of the first blank has a geometry that differs from the body of the second blank by other than scaling; for a given restoration R being designed, selecting a subset {B1, B2, . . . Bn) of “n” blanks, where n≦m, such that each of the blanks of the subset contain the restoration R; and selecting a given one of the blanks of the subset for use in producing the restoration. 15. The method of claim 14 wherein the given one of the blanks that is selected has the smallest volume. 16. The method of claim 14 wherein the given one of the blanks that is selected has a given yield. 17. The method of claim 14 wherein the body of at least one of the mill blanks in the assemblage has at most one symmetric plane. 18. The method of claim 14 wherein the dental item is prepared by milling the selected blank. 19. The method as described in claim 18 wherein the selected blank is milled using a computer-assisted milling machine. | This application is based on and claims priority from Provisional Patent Application Ser. No. 60/485,935, filed Jul. 9, 2003. BACKGROUND OF THE INVENTION 1. Technical Field This invention generally relates to a system for preparing dental prostheses. In particular, the invention relates a smart mill blank library and preparing dental prostheses for use as crowns, onlays, inlays, veneers, bridges, and other restorations from a mill blank selected from a mill blank library. 2. Related Art The art of fabricating custom-fit prosthetics in the dental field is well-known. Prosthetics are replacements for tooth or bone structure. They include restorations, replacements, inlays, onlays, veneers, full and partial crowns, bridges, implants, posts, and the like. Typically, a dentist prepares a tooth for the restoration by removing existing anatomy, which is then lost. The resultant preparation may be digitized or a dental impression is taken, for the purpose of constructing a restoration. The restoration may be constructed through a variety of techniques including manually constructing the restoration, using automated techniques based on computer algorithms, or a combination of manual and automated techniques. In one known technique, the prosthetic is fabricated using a computer-assisted (CAD/CAM) system, such as a computer-aided milling machine. One such machine is the CEREC 3D system from Sirona Dental Systems. Computer-aided machines of this type work by shaping the prosthetic from mill blanks. A mill blank is a solid block of material from which the prosthetic is shaped by a shaping apparatus whose movements are controlled by the computer. Under computer control, the size, shape, and arrangement of the restoration may be subject to various physical parameters, including neighboring contacts, opposing contacts, emergence angle, and color and quality of the restoration to match the neighboring teeth. A common restoration includes a porcelain-fused-to-metal (PFM) crown. The crown typically comprises a cap of porcelain material overlayed on a thin metal coping. The metal coping forms an interface between the preparation and the porcelain material. Common restorations typically include a coping formed from precious or semi-precious metals, including gold or a gold alloy. The material may be selected based on the color and various other properties to optimize a long-lasting natural looking restoration. The copings or full metal crowns typically are formed from a lost wax casting process. The process may include placing several wax copings on a wax tree, which is connected to a wax base. The structure is placed in a cylinder with investing material, and the wax is melted out after the investing material has set. A molten metal, typically a gold alloy, is then poured into the remaining structure, and the entire cylinder is placed into a centrifuge to distribute the molten material to a uniform distribution. Preferably, the alloy base and the tree are recovered for use in a future casting process. The continued re-melting of the gold alloy along with other contaminants, however, introduces oxidation and other tarnishing agents into the gold alloy. Other methods for forming the coping may be used, including milling or machining with some kind of block or blank, but these techniques may waste much of the metal material. The ratio of the volume of the final metal coping to the volume of a typical enclosing mill blank (a symmetric block or cylinder) is often very small such that much of the material may be wasted. As noted above, a common milling process includes forming the coping from a mill blank using a computer-assisted milling machine. The blank includes a sufficiently large rigid attachment so that it may be held solidly while the machining process is underway. A rectangular or cylindrical blank is commonly used, and the vast majority of material is removed via the machining process. U.S. Pat. No. 4,615,678 to Moermann et al. discloses a conventional mill blank of this type made of ceramic silica material. There are, of course, numerous other types of mill blanks available commercially. The cost of recovering the wasted material often exceeds the cost of the material sought to be recovered. The object may be milled using a wet milling process, which typically results in the discarded material (including fine particles) being mixed with water or other cutting fluids. This is not a significant concern when the restoration is being formed using inexpensive materials; however, when utilizing expensive materials, such as gold, the issue of dealing with the recovery of the machined material may make the process prohibitively expensive. Indeed, the cost of the discarded materials in the case of precious or semi-precious materials is the single most important reason that prior art techniques have proven to be undesirable or cost prohibitive. Additional concerns are the time required to cut through the discarded material, as well as the additional wear and tear on the tools. There have been a few incidental suggestions in the art to address this problem. Thus, for example, U.S. Pat. No. 4,615,678 teaches that the body portion of a mill blank can be formed in a way to minimize wear on and run time of the milling machine by being shaped initially to more closely resemble the final implant. An illustrative example is a blank for use in forming a two lobed inlay that includes a transverse groove in one side thereof. U.S. Published Patent Application 2003/0031984 to Rusin et al. illustrates a similar blank construction, and it further notes that blanks can come in a variety of shapes and sizes. While these suggestions are useful, there remains a need in the art to provide improved mill blank configurations and assemblages that facilitate prosthetic milling operations in a manner to reduce material waste, reduce machining time, and to increase value. BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to provide improved mill blank constructions to facilitate the manufacture of dental restorations. In general, this object is achieved by providing a given mill blank in a shape (i.e. with a given geometry) that has been predetermined to reduce material waste when the mill blank is machined into the final part. A mill blank that has been intelligently pre-configured into a form that more closely resembles the final dental part is sometimes referred to as a “smart” blank. It is a further object of the invention to provide such mill blanks in a collection or “assemblage.” A set of two or more smart blanks each having such characteristics is also sometimes referred to as a smart blank “library.” In a preferred embodiment, it is desirable to provide a smart blank library that includes a sufficient number of unique blanks such that, when the geometry of the designed restoration is known, the smart blank with a highest yield can be selected for use in milling the restoration. The “yield” of a given smart blank represents the amount of material of the smart blank that is actually used in the final restoration, with the higher the yield value meaning the closer the “fit” of the smart blank to the designed restoration. In a particular embodiment, a smart blank library is maintained with a given number of unique blanks so as to balance an average yield per smart blank with a goal of satisfying an inventory requirement for the library (e.g., the smallest possible library size necessary to meet anticipated production requirements over a given time period). In this embodiment, it is desirable to have a sufficient number of unique smart blanks in the library such that the smart blank with a highest average yield can be selected and is available for use while ensuring that the number of blanks remains within a given inventory production factor. According to a more specific embodiment, an assemblage of blanks comprises at least first and second smart blanks, with each smart blank adaptable for producing a formed part that can be used for replacement or restoration of one or more teeth by removing as little material from the blank as possible (i.e., an optimize yield). The first blank has a first geometry, and the second blank has a second geometry that differs from the first geometry other than by mere scaling. The first blank is configured to resemble a first given restoration, and the second blank is configured to resemble a second given restoration. Each of the blanks further includes a holder (a sprue) for mounting the blank in a shaping apparatus. The blank comprises a precious or semi-precious material, a ceramic silica material, or other material suitable for the substructure or final restoration. It is another more general object of the invention to provide a smart mill blank library that comprises multiple smart mill blanks having a variety of predetermined shapes, sizes, and arrangements. Preferably, a given smart mill blank in the library is pre-formed to a target size, shape and arrangement so that the library as a whole is useful across for a particular set of applications. Thus, depending on the type and nature of the restoration, a particular smart mill blank is selected from the library and used in the milling operation. As a result, the amount of material needed to be removed from the mill blank is reduced greatly. This is especially desirable and cost-effective when precious or semi-precious materials (such as gold) are being used in the restoration. Indeed, use of a smart blank pre-formed from gold significantly reduces the amount of gold to be recovered, in many cases reducing it to less than that in a common lost wax casting process. In addition, the amount of time to machine the restoration is reduced due to a relatively small amount of material that needs to be removed from the smart mill blank. The use of such blanks provides further process advantages including, without limitation, reducing spoiling effects such as gold alloy tarnishing, eliminating trace metal oxidation, and the like. Another more general object of the present invention is to provide a smart blank library that achieves maximum yield, so as to minimize material waste. According to a specific feature of the present invention, the smart blank library comprises a set of copings or full contour crowns. A coping is the substructure of a crown. The general shape of a coping has an upper surface and a lower surface. The upper surface is generally a convex surface and the lower surface is generally a concave surface. The lower surface is configured to be able to be affixed to a dental preparation and to form a tight seal at a margin having a small but definite gap for cement. The general shape of the lower surface may mirror or correspond to the shape of a typical preparation. The general shape of the upper surface of the coping may correspond to an occlusal surface of a particular dental item. A selection of a smart mill blank from the library provides a more effective way to prepare a dental prosthesis and dental item to maintain optimal porcelain or other surface material on top of the metal coping. In a common restoration, such as a porcelain-on-metal crown, it is desirable for longevity of the restoration to provide a substantially constant thickness of the porcelain material. Maintaining the constant thickness may reduce a risk of fracturing the material. Accordingly, in one embodiment, the smart mill blanks in the library may have a generally concavo-convex shape, with the top surface having a shape that allows the porcelain-sculpted anatomy to exhibit a near constant thickness Other methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be better understood with reference to the following drawings and its accompanying description. Unless otherwise stated, the components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views. FIG. 1 illustrates a smart blank library according to an embodiment of the present invention; FIG. 2 illustrates another embodiment of the invention where the smart blank library has been sized to satisfy a given yield, productivity, cost or other factor; FIG. 3 illustrates a computer system that may be used to facilitate selection of a smart blank from the library of FIG. 2, FIG. 4 illustrates how a first restoration is tested against a set of smart blanks in a given library to determine whether the restoration is containable therein; FIG. 5 illustrates how a second restoration is tested against the set of smart blanks in the given library of FIG. 4 to determine whether the restoration in containable therein; FIG. 6 illustrates the smart blanks selected for use in the manufacture of the first and second restorations; FIG. 7 illustrates conventional mill blanks each having a large amount of material that is discarded when the respective blank is shaped in a prior art milling process; FIG. 8 illustrates a pair of smart mill blanks each having a shape and arrangement that closely approximates a final shape of a respective coping or crown; FIG. 9A illustrates a smart mill blank library of multiple mill blanks that may be selected based on size, shape and arrangement of the mill blank for the purposes of producing a coping; and FIG. 9B illustrates a smart mill blank library of multiple mill blanks that may be selected based on size, shape and arrangement of the mill blank for the purposes of producing a full crown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For illustrative purposes, the following terms may be afforded the following meanings in the context of the present invention: A “blank” is a part adapted for use in custom fabrication of a dental restoration. Typically, a blank comprises a body for being shaped by material removal, and a holder (a “sprue”) for mounting the blank in a shaping apparatus such as a CAD/CAM (or other) milling machine, device or system. A “smart blank” is a blank that has been pre-configured into a form that, as compared to a conventional blank, much more closely resembles a restoration being designed. A “yield” of a smart blank is the amount of material of the body part that ends up being useful for the restoration during the milling of the blank. According to the present invention, it is desirable to maintain a library of smart blanks such that, in use, an optimized yield per blank (and, thus, an optimized yield across the library as whole) is obtained. A “library” (or “collection,” or “assemblage”) of smart blanks is a set of two or more smart blanks, with each blank adaptable for producing a formed part that can be used for replacement or restoration of one or more teeth, preferably by removing as little material from the blank as possible (i.e., to optimize yield per blank). Preferably, at least a first blank has a first geometry, and the second blank has a second geometry that differs from the first geometry by other than scaling. FIG. 1 illustrates a library 100 comprised of two blanks 102 and 104 that meet this criteria. A “restoration” refers generically to a crown, coping, bridge, onlay, inlay, framework, or other dental item. An “average yield per blank” is an average yield per blank, calculated as a weight of a finished restoration divided by a weight of an initial smart blank. Thus, e.g., if a milled coping weighs 1.5 penny weights and the smart blank (pulled from the library) weighs 3.0 penny weights), the average yield for this blank is 50%. A “size” of the smart blank library refers to the number of unique smart blanks in the library. A “production period” is an average number of restorations produced within a given dental laboratory or office over a given period (e.g., daily, weekly, monthly, or the like). An “inventory over production factor” is the surplus, or amount of inventory that exceeds an average production for a given production period. Thus, assume the production period is daily. If a laboratory fabricates 40 restorations per day (200 per week) and 80 smart blanks per day (400 per week) are needed to fulfill production requirements, the inventory over production factor is 100%. A laboratory should have sufficient smart blanks to satisfy its production requirements for some specified period of time. An “intrinsic cost of the average restoration” is the cost of the raw material used to create the finished restoration such as a coping. A “distribution by tooth number” is a weighted distribution based upon laboratory productivity by tooth type (e.g., 27% 3rd molar, 22%, 2nd molar, 11%, 1st molar, 14%, 2nd bicuspid, 12%, 1st bicuspid, and the like). An “average scrap per smart blank” is one minus the average yield per smart blank. A “scrap factor” is 100% divided by the average yield per smart blank. Thus, for example, if the average yield per smart blank is 50%, the scrap factor is 2.0). A “cost per restoration” is the scrap factor times the intrinsic cost of the average restoration. As noted above, FIG. 1 illustrates a smart blank library 100 that comprises at least a first smart blank 102, and a second smart blank 104. Each blank comprises a body 106 for being shaped by material removal, and a holder 108 for mounting the blank in a shaping apparatus. Preferably, the body 106 has a given geometry that will closely resemble a given restoration under design. Although not meant to be taken by way of limitation, preferably the body of a given smart blank has, at most, one symmetric plane. In this illustrative embodiment, the given geometry of the body of the first smart blank 102 differs from the given geometry of the body of the second smart blank 104 by other than scaling. The body may be formed of any suitable blank material including, without limitation, a precious metal or metal alloy, a semi-precious metal or metal alloy, a ceramic or other inorganic non-metallic material, or the like. The body is adapted to be formed or milled into any type of restoration (or other dental prosthetic) by hand or by a milling machine, such as a machine that uses a CAD/CAM system. Any convenient cutting technique can be used for this purpose. More generally, a smart mill blank library comprises a plurality of smart mill blanks. The smart mill library includes a set of smart blanks having a pre-formed size shape and arrangement that approximates dental crown of various known tooth types and common dental preparations. The library may also include a set of smart mill blanks having a size, shape and arrangement that approximates copings for various types of teeth and common preparations. FIG. 2 illustrates a smart library 200 as it is maintained in a given dental laboratory or office. It is assumed that this library has been drawn from a larger, global set of available smart blanks (a set that could be quite large in size theoretically given the variations in smart blank shapes). It is further assumed that the given dental laboratory or office only desires to maintain an inventory of smart blanks for which it expects to have demand and/or that satisfy some other inventory requirements. To this end, it is a further feature of the present invention to provide or maintain a smart blank library 200 of “n” smart blanks (as illustrated in the figure by a library of eight (8) smart blanks 201-208), where the library 200 has a smallest possible “size” (not necessarily of size 8, as illustrated) to satisfy a given criteria. One such criterion simply is the average yield per smart blank, as defined above. According to this example, the smart blank library 200 is sized with a set of unique blanks so that, when the geometry of the designed restoration is calculated or known (the particular technique by which this is done is not part of the present invention), an operator is provided with an indication of which smart blank to use, namely, the smart blank that offers the highest yield. In this example, this is the blank that is “closest” to the designed restoration, i.e., the blank with the least amount of material to be removed to satisfy the given design under construction. Thus, in one embodiment, the smart blank library is stocked by selecting an assemblage of the blanks that satisfy a given criterion, where the given criterion is a maximum average yield per blank, and the smart blanks are then used to manufacture dental restorations. As an alternative, the given criterion is that a weighted average of the blank yields in the assemblage is maximized. Still another alternative criterion is that a weighted average of the blank yields in the assemblage is maximized. Another alternative criterion balances an average yield per blank with a given productivity factor. A further variant would be to use a criterion that balances an average yield per blank with a given cost factor. Yet another given criterion balances among any of a set of yield, productivity, cost and/or tooth distribution factors, as more particularly described in the following paragraph by way of some specific examples. One possibility to determine the library size is to use a given criterion that the average yield per smart blank be greater than a given selectable value for a given number of restorations for a given tooth (or tooth group), e.g., select a blank that results in at least a 70% yield for 80% of the restorations for a given tooth. The distribution by tooth number can be used to provide the data for this selection. Another way to maintain an appropriate library size is to enforce a highest average yield per blank while maintaining the inventory production factor within a given acceptable range. The inventory production factor may take into consideration the distribution by tooth number data as well. Still another criterion for sizing the library is to maintain smart blanks that exhibit a given yield within a given difference factor (e.g., a standard deviation, or multiple thereof) from a mean of a normal distribution of a tooth population. Another sizing criterion is to maintain sufficient smart blanks to facilitate trading off an average yield per smart blank and an intrinsic cost of the average restoration, thereby providing the operator with a blank that has a reasonably good yield but also considers the actual cost of the material being used. The above are merely illustrative ways of maintaining a smart blank library in a cost-effective, demand-driven manner. Preferably, the sizing of the library (e.g., the selection of which blanks that the library will include) is done as an automated (computer-assisted) process, although this is not a requirement taking into consideration one or more of the above-described process variables. Generalizing, according to a feature of the invention, there are many possible criteria that may be used to determine the number (and possibly the types) of smart blanks to maintain in a given assemblage. In a preferred embodiment, the goal of optimizing yield typically is an important factor. It is now assumed that a smart blank library is being maintained (preferably according to one or more of the inventory techniques described above), and that a restoration is ready to be designed. The following description provides further details of a representative algorithm for selecting a smart blank in the library that is “closest” to the restoration being designed R. Without loss of generality, it is assumed that the restoration R is described in 3D by a closed polygon mesh or, more generally, by any other closed parameterized surface, such as Non-Uniform Rationale B-Spline surface (NURB). FIGS. 4 and 5 illustrate two such restorations 402 and 502. Of course, these shapes are merely exemplary. Continuing with the algorithm, it is assumed that each available blank Bi in the library also is defined by a closed parameterized surface representation, where the size of the library is m. According to a preferred embodiment, a subset {B1, B2, . . . Bn} of n blanks is then selected, where each of the elements in the subset satisfies the following condition: R⊂Bi, for i=1, . . . n. It should be noted that this condition is met only if there exists a relative transformation between R and B such that no point on R is visible from any vantage point outside of B. Stated another way, a blank that satisfies this condition is said to “contain” the restoration. Then, the blank of the subset with the smallest volume is selected as the blank from which the restoration R will be milled or machined. In particular, because each of the blanks of the subset contains the restoration, the one with the smallest volume will necessarily produce the highest yield. The above-described example is preferred, but variants are within the scope of the invention. Thus, instead of selecting the blank of the subset with the smallest volume (and thus the highest yield), an alternative would be to choose the blank with the second highest yield (for example, because inventory of the first blank may be too low, because the first blank is made from a material that is more costly than the material of the blank with a next highest yield, and so forth). As another alternative, instead of selecting the blank of the subset with the highest yield, a blank that has an acceptable yield may be chosen. The above are merely representative examples. Any particular selection criteria (e.g., based on yield, productivity, cost, tooth distribution, or combinations of such variables) may be used to facilitate the smart blank selection process once the subset {B1, B2, . . . Bn} satisfying the containment condition has been determined. A computer or computer system as illustrated in FIG. 3 preferably is used to facilitate the above-described algorithm and selection process. An illustrative computer 300 comprises Intel-commodity hardware 302, suitable storage 303 and memory 304 for storing an operating system 306 (such as Linux, W2K, or the like), software applications 308a-n and data 310, conventional input and output devices (a display 312, a keyboard 314, a mouse 316, and the like), devices 318 to provide network connectivity, and the like. Using a conventional graphical user interface 320, an operator can select from a menu 322 given criterion by which the smart blank selection is to be effected, or create a custom criterion using one or more of the above-described variables (or other factors). In use, it is assumed that a given geometry of the designed restoration is made available to the computer system. The system has knowledge of the unique geometries of each of the smart blanks then available from the library. Using a given criterion (which the operator can select or that may be a default), the system then selects the smart blank from the available blanks that satisfies the given criterion, or that satisfies the given criterion within a given acceptance factor. As noted above, the present invention enables the operator to select the smart blank from the subset based on the factors it deems appropriate and suitable for its particular purposes. As described above, the computer-implemented smart blank selection process first determines the subset {B1, B2, . . . Bn} of smart blanks that satisfy the containment condition. The subset determination for two different restorations given a smart library of two blanks 102 and 104 is illustrated in FIGS. 4-6. As seen in FIG. 4, the restoration 402 is containable within smart blank 102 but not within smart blank 104. Thus, for this particular restoration, only smart blank 102 would be a candidate for the final selection, i.e., only smart blank 102 is in the subset. In FIG. 5, however, the restoration 502 is containable within both smart blank 102 and smart blank 104; as a consequence, both blanks are candidates for the final selection, i.e., both are in the subset. In the preferred embodiment as has been described above, the smart blank of the subset with the lowest volume (thus, the highest yield) is then selected for use in milling the restoration. With respect to restoration 402, this condition does not matter (at least in this example), as blank 102 is the only blank in the subset. With respect to restoration 502, however, there are two choices. Accordingly, as seen in FIG. 6, smart blank 102 is used for the manufacture of restoration 402 while smart blank 104 (the one with the smallest volume) is used for the manufacture of restoration 502. The following describes one computer-implemented technique for making a smart blank assemblage, although any particular technique (such as casting or forging) may be used. In general, a shape for the sets of smart blanks may be selected according to a particular application. Thus, for example, for each set, multiple (one hundred or more) cases are evaluated, where a digital impression is made of each preparation, for each type of preparation and for each tooth number in the American standard tooth numbering scheme. For each such preparation, an ideal crown or coping designed for that preparation is desired to be pre-formed as a smart blank, as described above. A percentage completed factor C is chosen. A standard mill blank (typically a block or cylinder) is then selected. The volume of material V to be removed from the standard mill block is then determined based on the dimensions of the mill block and the model of the final crown or coping to be milled. A target material removal volume U is calculated by U=CV/100. By way of example, V may be 100 mm3 and C may be 60%, then U=60 mm3. The yield for the particular smart blank is then equal to 100%−C. A standard mill blank (FIG. 7) may be partially milled or machined to create the smart blank. Similarly, the milling or machining process may be simulated, e.g, by a digital processor that is suitably programmed with computer software. The milling procedure is performed on a standard mill blank and the milling or machining process terminated when the amount of material that has been removed has reached or exceeds U. This is illustrated in FIG. 8. In each case, a series of partially machined crowns or copings may be formed. A number n of test cases will result in n shapes. A tolerance percentage factor T may be selected. A subset of the shapes determined above may be selected based on criterion such as: for each test case, there must exist in the shape library a shape where no more than TV/100 volume of material must be removed where V is the volume of the shape from the shape library. Accordingly, the larger the tolerance percentage factor T, the smaller the subset. Based on the C and T parameters and n test cases, a set of m shapes where 0<m<=n may be formed, in which the m shapes comprise a smart mill blank library. Each shape may be mass produced according to the shapes determined above. As noted above, an integrated milling attachment (the holder or sprue) is included with each shape to provide attachment for the milling and machining process. The attachment may be formed from the same or other material as the smart mill blank. For each smart mill blank, a partial or a full three-dimensional (3D) model or computer aided design (CAD) model for the shape and attachment may be recorded and associated with the smart blank. The 3D and CAD model information may be useful for final milling of the smart blank. As noted above, an illustrative embodiment includes a process in which a proposed restoration is digitally scanned, using a 3D data acquisition technique. An optimum coping to fit on top of the restoration may then be determined via a computer-based matching algorithm. Every dimension (or, optionally, certain key dimensions) of the coping are determined from the digital data. This shape is compared with the library of smart mill blanks, and a smart blank selected for which conditions are satisfied. As used herein, a selection may be computer-generated, or the operator may be provided with an indication of which smart blanks “best” fit the design. In particular, the smart mill blank may be selected so that the desired coping fits entirely within the smart mill blank and so that the volume difference between the coping and smart mill blank is minimized, i.e., so that the yield is optimized. According to another embodiment, the smart mill blank library comprises mill blanks for one or more of the following: molars, pre-molars, bicuspids, canines, upper central incisors, upper lateral incisors and lower incisors, along with some size variation allowed for different patients. In addition, the library may also use as an input variable the ethnicity and sex of the patient. Using the chosen smart mill blank as a starting point, the amount of material cut off may be minimized, thereby optimizing yield. The smart mill blank library also provides for reduced quicker machining time and reduced recovery process. The blanks may be formed from precious, semi-precious, non-precious metals, metal alloys, composite materials, or any other material suitable for dental applications. Where precious metal may be used, the invention provides much more viable alternative from an economics point of view by reducing the amount of material that is wasted and recovered. In still another embodiment, the smart mill blank library comprises a series of blanks made up of a generally convex or concavo-convex upper surface attached to a concave lower surface, with an integrated milling attachment with an orientation-specific attachment key for the milling machine. A variety of combinations may be formed with different upper surfaces attached to different lower surfaces to form a large library of smart blanks. FIG. 9B illustrates a representative library of this type. In yet another embodiment as illustrated in FIG. 9B, the smart mill blank library comprises a set of partial spherical shells of different sizes and thicknesses. Each shell may include an integrated milling attachment. The attachment may have an orientation-specific attachment key for a milling machine. The digitally produced coping may be machined from a selected blank, for which the cut-off material is minimized during the machining process. In a still further embodiment, the smart mill blank library comprises a series of flattened dimpled spherical solids of different sizes and thicknesses. Each solid may have an integrated milling attachment with an orientation-specific attachment key for the milling machine. According to another embodiment, the smart mill blank library comprises a set of mill blanks appropriate for copings for one of any one of different classes of teeth, such as molars, premolars, bicuspids, canines and incisors. In a further embodiment, the smart mill blank library comprises a set of mill blanks appropriate for crowns for one of any one of different classes of teeth, such as molars, premolars, bicuspids, canines and incisors. Another embodiment of the invention is a smart blank library comprising a set of mill blanks appropriate for copings for many different classes of teeth, such as molars, premolars, bicuspids, canines and incisors, along with size variations in each class. In another embodiment, the smart mill blank library comprises set of different blanks that are selected to enable all possible cases to be milled from one of the mill blanks. The general shapes of the mill blanks may be selected so that a difference in volume between the desired coping and at least one library blank is determined to be less than a predetermined tolerance. The tolerance may be determined according to economic or other reasons. In still another embodiment, the smart mill blank library comprises two sets of blanks: a set of smart crown mill blanks to be used to mill full crowns; and a set of smart coping mill blanks to be used to mill copings. This is illustrated in FIGS. 9A and 9B. Each set is determined by examining multiple real cases and partially forming a standard mill block to make the desired coping or crown. By setting a criterion of a certain percentage of material loss that is permitted in completing the machining or milling, a subset of those partially machined or milled blanks is selected, and those shapes are used for the smart mill blank library. While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible and modifications may be made that are within the scope of the invention. It should be appreciated that the apparatuses and methods of the present invention are capable of being incorporated in the form of a variety of embodiments without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. As noted above, materials used to make the prostheses typically include gold, ceramics, amalgam, porcelain and composites. For dental restorative work such as fillings, amalgam is a popular choice for its long life and low cost. Amalgam also provides a dental practitioner the capability of fitting and fabricating a dental filling during a single session with a patient. The aesthetic value of amalgam, however, is quite low, as its color drastically contrasts to that of natural teeth. For large inlays and fillings, gold is often used. However, similar to amalgam, gold fillings contrast to natural teeth hues. As noted above, in the present invention, the smart blanks may be formed of any type of material normally used for dental restorations. In the embodiments described above, each of the smart blanks in the library has a geometry that differs from the geometry of other smart blanks in the library by other than scaling. This is a preferred approach, but it is not always a requirement. As noted above, preferably both the smart blank inventory management process and the smart blank selection process are automated, i.e., under the control of a suitably programmed processor or other controller. While certain aspects or features of the present invention have been described in the context of a computer-based method or process, this is not a limitation of the invention. Moreover, such computer-based methods may be implemented in an apparatus or system for performing the described operations, or as an adjunct to other dental milling equipment, devices or systems. This apparatus may be specially constructed for the required purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. The computer may be connected to any wired or wireless network. Further, the above-described functions and features may be implemented within or as an adjunct to other known dental milling equipment, devices or systems. Further, while the above written description also describes a particular order of operations performed by certain embodiments of the invention, it should be understood that such order is exemplary, as alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, or the like. References in the specification to a given embodiment indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Technical Field This invention generally relates to a system for preparing dental prostheses. In particular, the invention relates a smart mill blank library and preparing dental prostheses for use as crowns, onlays, inlays, veneers, bridges, and other restorations from a mill blank selected from a mill blank library. 2. Related Art The art of fabricating custom-fit prosthetics in the dental field is well-known. Prosthetics are replacements for tooth or bone structure. They include restorations, replacements, inlays, onlays, veneers, full and partial crowns, bridges, implants, posts, and the like. Typically, a dentist prepares a tooth for the restoration by removing existing anatomy, which is then lost. The resultant preparation may be digitized or a dental impression is taken, for the purpose of constructing a restoration. The restoration may be constructed through a variety of techniques including manually constructing the restoration, using automated techniques based on computer algorithms, or a combination of manual and automated techniques. In one known technique, the prosthetic is fabricated using a computer-assisted (CAD/CAM) system, such as a computer-aided milling machine. One such machine is the CEREC 3D system from Sirona Dental Systems. Computer-aided machines of this type work by shaping the prosthetic from mill blanks. A mill blank is a solid block of material from which the prosthetic is shaped by a shaping apparatus whose movements are controlled by the computer. Under computer control, the size, shape, and arrangement of the restoration may be subject to various physical parameters, including neighboring contacts, opposing contacts, emergence angle, and color and quality of the restoration to match the neighboring teeth. A common restoration includes a porcelain-fused-to-metal (PFM) crown. The crown typically comprises a cap of porcelain material overlayed on a thin metal coping. The metal coping forms an interface between the preparation and the porcelain material. Common restorations typically include a coping formed from precious or semi-precious metals, including gold or a gold alloy. The material may be selected based on the color and various other properties to optimize a long-lasting natural looking restoration. The copings or full metal crowns typically are formed from a lost wax casting process. The process may include placing several wax copings on a wax tree, which is connected to a wax base. The structure is placed in a cylinder with investing material, and the wax is melted out after the investing material has set. A molten metal, typically a gold alloy, is then poured into the remaining structure, and the entire cylinder is placed into a centrifuge to distribute the molten material to a uniform distribution. Preferably, the alloy base and the tree are recovered for use in a future casting process. The continued re-melting of the gold alloy along with other contaminants, however, introduces oxidation and other tarnishing agents into the gold alloy. Other methods for forming the coping may be used, including milling or machining with some kind of block or blank, but these techniques may waste much of the metal material. The ratio of the volume of the final metal coping to the volume of a typical enclosing mill blank (a symmetric block or cylinder) is often very small such that much of the material may be wasted. As noted above, a common milling process includes forming the coping from a mill blank using a computer-assisted milling machine. The blank includes a sufficiently large rigid attachment so that it may be held solidly while the machining process is underway. A rectangular or cylindrical blank is commonly used, and the vast majority of material is removed via the machining process. U.S. Pat. No. 4,615,678 to Moermann et al. discloses a conventional mill blank of this type made of ceramic silica material. There are, of course, numerous other types of mill blanks available commercially. The cost of recovering the wasted material often exceeds the cost of the material sought to be recovered. The object may be milled using a wet milling process, which typically results in the discarded material (including fine particles) being mixed with water or other cutting fluids. This is not a significant concern when the restoration is being formed using inexpensive materials; however, when utilizing expensive materials, such as gold, the issue of dealing with the recovery of the machined material may make the process prohibitively expensive. Indeed, the cost of the discarded materials in the case of precious or semi-precious materials is the single most important reason that prior art techniques have proven to be undesirable or cost prohibitive. Additional concerns are the time required to cut through the discarded material, as well as the additional wear and tear on the tools. There have been a few incidental suggestions in the art to address this problem. Thus, for example, U.S. Pat. No. 4,615,678 teaches that the body portion of a mill blank can be formed in a way to minimize wear on and run time of the milling machine by being shaped initially to more closely resemble the final implant. An illustrative example is a blank for use in forming a two lobed inlay that includes a transverse groove in one side thereof. U.S. Published Patent Application 2003/0031984 to Rusin et al. illustrates a similar blank construction, and it further notes that blanks can come in a variety of shapes and sizes. While these suggestions are useful, there remains a need in the art to provide improved mill blank configurations and assemblages that facilitate prosthetic milling operations in a manner to reduce material waste, reduce machining time, and to increase value. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide improved mill blank constructions to facilitate the manufacture of dental restorations. In general, this object is achieved by providing a given mill blank in a shape (i.e. with a given geometry) that has been predetermined to reduce material waste when the mill blank is machined into the final part. A mill blank that has been intelligently pre-configured into a form that more closely resembles the final dental part is sometimes referred to as a “smart” blank. It is a further object of the invention to provide such mill blanks in a collection or “assemblage.” A set of two or more smart blanks each having such characteristics is also sometimes referred to as a smart blank “library.” In a preferred embodiment, it is desirable to provide a smart blank library that includes a sufficient number of unique blanks such that, when the geometry of the designed restoration is known, the smart blank with a highest yield can be selected for use in milling the restoration. The “yield” of a given smart blank represents the amount of material of the smart blank that is actually used in the final restoration, with the higher the yield value meaning the closer the “fit” of the smart blank to the designed restoration. In a particular embodiment, a smart blank library is maintained with a given number of unique blanks so as to balance an average yield per smart blank with a goal of satisfying an inventory requirement for the library (e.g., the smallest possible library size necessary to meet anticipated production requirements over a given time period). In this embodiment, it is desirable to have a sufficient number of unique smart blanks in the library such that the smart blank with a highest average yield can be selected and is available for use while ensuring that the number of blanks remains within a given inventory production factor. According to a more specific embodiment, an assemblage of blanks comprises at least first and second smart blanks, with each smart blank adaptable for producing a formed part that can be used for replacement or restoration of one or more teeth by removing as little material from the blank as possible (i.e., an optimize yield). The first blank has a first geometry, and the second blank has a second geometry that differs from the first geometry other than by mere scaling. The first blank is configured to resemble a first given restoration, and the second blank is configured to resemble a second given restoration. Each of the blanks further includes a holder (a sprue) for mounting the blank in a shaping apparatus. The blank comprises a precious or semi-precious material, a ceramic silica material, or other material suitable for the substructure or final restoration. It is another more general object of the invention to provide a smart mill blank library that comprises multiple smart mill blanks having a variety of predetermined shapes, sizes, and arrangements. Preferably, a given smart mill blank in the library is pre-formed to a target size, shape and arrangement so that the library as a whole is useful across for a particular set of applications. Thus, depending on the type and nature of the restoration, a particular smart mill blank is selected from the library and used in the milling operation. As a result, the amount of material needed to be removed from the mill blank is reduced greatly. This is especially desirable and cost-effective when precious or semi-precious materials (such as gold) are being used in the restoration. Indeed, use of a smart blank pre-formed from gold significantly reduces the amount of gold to be recovered, in many cases reducing it to less than that in a common lost wax casting process. In addition, the amount of time to machine the restoration is reduced due to a relatively small amount of material that needs to be removed from the smart mill blank. The use of such blanks provides further process advantages including, without limitation, reducing spoiling effects such as gold alloy tarnishing, eliminating trace metal oxidation, and the like. Another more general object of the present invention is to provide a smart blank library that achieves maximum yield, so as to minimize material waste. According to a specific feature of the present invention, the smart blank library comprises a set of copings or full contour crowns. A coping is the substructure of a crown. The general shape of a coping has an upper surface and a lower surface. The upper surface is generally a convex surface and the lower surface is generally a concave surface. The lower surface is configured to be able to be affixed to a dental preparation and to form a tight seal at a margin having a small but definite gap for cement. The general shape of the lower surface may mirror or correspond to the shape of a typical preparation. The general shape of the upper surface of the coping may correspond to an occlusal surface of a particular dental item. A selection of a smart mill blank from the library provides a more effective way to prepare a dental prosthesis and dental item to maintain optimal porcelain or other surface material on top of the metal coping. In a common restoration, such as a porcelain-on-metal crown, it is desirable for longevity of the restoration to provide a substantially constant thickness of the porcelain material. Maintaining the constant thickness may reduce a risk of fracturing the material. Accordingly, in one embodiment, the smart mill blanks in the library may have a generally concavo-convex shape, with the top surface having a shape that allows the porcelain-sculpted anatomy to exhibit a near constant thickness Other methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. | 20040709 | 20051227 | 20050113 | 64492.0 | 0 | LA VILLA, MICHAEL EUGENE | MILL BLANK LIBRARY AND COMPUTER-IMPLEMENTED METHOD FOR EFFICIENT SELECTION OF BLANKS TO SATISFY GIVEN CRITERIA | SMALL | 0 | ACCEPTED | 2,004 |
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10,887,599 | ACCEPTED | Placement of a clock signal supply network during design of integrated circuits | A method of placing a clock signal supply network in a design representation for an integrated circuit. The design representation may comprise a plurality of clockable circuit cells. The method may comprise identifying a first of the clockable circuit cells in the design representation. The method may further comprise identifying a second of the clockable circuit cells in the design representation. The second clockable circuit cell may have a clock timing dependent relation relative to the first clockable circuit cell. The method may further comprise configuring the clock signal supply network. The clock signal supply network may be configured to supply respective clock signals to the first and said second clockable circuit cells. The clock signal supply network may be configured to route the respective clock signals such that a timing difference between the respective clock signals is protected from process, voltage and temperature (PVT) influences. | 1. A method of placing a clock signal supply network in a design representation for an integrated circuit, the design representation comprising a plurality of clockable circuit cells, and the method comprising: (a) identifying a first of said clockable circuit cells in said design representation; (b) identifying a second of said clockable circuit cells in said design representation, said second clockable circuit cell having a clock timing dependent relation relative to said first clockable circuit cell; and (c) configuring said clock signal supply network to (i) supply respective clock signals to said first and said second clockable circuit cells, and (ii) route said respective clock signals such that a timing difference between said respective clock signals is protected from process, voltage and temperature (PVT) influences. 2. The method of claim 1, wherein said design representation comprises a first location for said first clockable circuit cell and a second location for said second clockable circuit cell, said second location being non-adjacent to said first location. 3. The method of claim 1, wherein step (c) comprises the sub-steps of: inserting a clock supply network comprising a divided portion divided between said first and said second clockable circuit cells, and a common portion coupled to said divided portion; and configuring at least one repeater cell in said clock supply network, such that a greater number of repeater cells is provided in said common portion than in said divided portion. 4. The method of claim 3, wherein said divided portion comprises no repeater cells. 5. The method of claim 1, wherein said respective clock signals comprise a common clock signal for said first and said second clockable circuit cells. 6. The method of claim 1, wherein said second clockable circuit cell is configured to receive a signal directly or indirectly from an output of said first clockable circuit cell. 7. The method of claim 1, wherein steps (a) and (b) comprise performing an analysis of a connectivity between said plurality of clockable circuit cells. 8. The method of claim 1, wherein steps (a) and (b) comprise performing an analysis of a timing relationship between said plurality of clockable cells. 9. The method of claim 1, wherein step (c) comprises the sub-step of: routing a first clock supply path for said first clockable circuit cell, and a second clock supply path for said second clockable cell, in closely adjacent relationship. 10. The method of claim 1, wherein step (c) comprises the sub-step of: identifying, from said design representation, combinatorial logic that directly or indirectly creates a difference between said respective clock signals; creating a version of said combinatorial logic that duplicates a structure of said combinatorial logic; and including said version of said combinatorial logic in at least one clock path of said clock supply network for supplying said respective clock signals. 11. The method of claim 1, wherein step (a) comprises the sub-steps of: identifying at least one signal path that passes through plural ones of said plurality of clockable circuit cells; identifying said first clockable circuit cell at a first end of said signal path; and identifying said second clockable circuit cell at a second end of said signal path. 12. The method of claim 11, further comprising the step of identifying a clock node that (i) represents a common source from which said respective clock signals for said first and said second clockable circuit cells are derived, and (ii) is closest to said first and said second clockable circuit cells. 13. The method of claim 12, further comprising the step of defining a cluster of clockable circuit cells from said plurality of clockable circuit cells, said cluster including respective clockable circuit cells associated with said signal path. 14. A computer based design tool for placing a clock signal supply network in a design representation for an integrated circuit, the design representation comprising a plurality of clockable circuit cells, and the tool being configured to: (a) identify a first of said clockable circuit cells in said design representation; (b) identify a second of said clockable circuit cells in said design representation, said second clockable circuit cell having a clock timing dependent relation relative to said first clockable circuit cell; and (c) configure said clock signal supply network to (i) supply respective clock signals to said first and said second clockable circuit cells, and (ii) route said respective clock signals such that a timing difference between said respective clock signals is protected from process, voltage and temperature (PVT) influences. 15. The tool of claim 14, wherein said step of configuring said clock signal supply network comprises: inserting a clock supply network comprising a divided portion divided between said first and said second clockable circuit cells, and a common portion coupled to said divided portion; and configuring at least one repeater cell in said clock supply network, such that a greater number of repeater cells is provided in said common portion than in said divided portion. 16. The tool of claim 14, wherein said step of configuring said clock signal supply network comprises: routing a first clock supply path for said first clockable circuit cell, and a second clock supply path for said second clockable cell, in closely adjacent relationship. 17. An integrated circuit comprising: a plurality of clockable circuit cells including a first clockable circuit cell and a second clockable circuit cell having a clock timing dependent relation relative to said first clockable circuit cell; and a clock supply network for supplying respective clock signals to said plurality of clockable circuit cells, said clock supply network being configured such that a timing difference between said respective clock signals is protected from process, voltage and temperature (PVT) influences. 18. The integrated circuit of claim 17, wherein said first and said second clockable circuit cells are located at non-adjacent locations. 19. The integrated circuit of claim 17, wherein said clock supply network comprises a divided portion divided between said first and said second clockable circuit cells, and a common portion coupled to said divided portion; and said common portion comprises a greater number of repeater cells than said divided portion. 20. The integrated circuit of claim 17, wherein said clock supply network comprises first and second clock signal paths for supplying said respective clock signals to said first and said second clockable circuit cells, said first and second signal paths being routed to be closely adjacent each other. | FIELD OF THE INVENTION The present invention may relate to a method, apparatus and/or design tool for placing a clock signal supply network during the design of an integrated circuit. The invention may especially relate to an automated technique for placing such a network. BACKGROUND TO THE INVENTION One of the steps of designing an integrated circuit layout is to arrange for clock signals to be supplied to clocked cells of the circuit. A computer based design tool is used to automatically design a clock signal supply network (clock tree) according to predetermined design rules. The clock tree has multiple branches to deliver clock signals to different circuit cells, at different locations, on an integrated circuit die. The branches typically include active circuit cells through which the clock signal passes. Typical active cells include repeater cells for preserving the clock signal in long signal paths, and clock gate cells for selectively blocking or applying the clock signal. In a balanced clock tree, the branches are designed to have generally the same signal path length in each branch in an attempt to reduce clock skew between the branches. Controlling clock skew is an important part of the design process. Clock skew affects the relative timing at which different cells in the integrated circuit operate. Clock skew can be a limiting factor on the maximum operating speed of one or more parts of the integrated circuit or the integrated circuit as a whole. In practice, undesirable clock skew between two or more branches of a clock tree remains a significant design problem. The problem is becoming increasingly apparent as greater demands are made on speed, performance, complexity and fabrication size and density of integrated circuits. Current automatic design tools for placing clock trees lack sufficient refinement for optimizing clock trees in demanding or speed critical designs. SUMMARY OF THE INVENTION The present invention may relate to a method of placing a clock signal supply network in a design representation for an integrated circuit. The design representation may comprise a plurality of clockable circuit cells. The method may comprise identifying a first of the clockable circuit cells in the design representation. The method may further comprise identifying a second of the clockable circuit cells in the design representation. The second clockable circuit cell may have a clock timing dependent relation relative to the first clockable circuit cell. The method may further comprise configuring the clock signal supply network. The clock signal supply network may be configured to supply respective clock signals to the first and said second clockable circuit cells. The clock signal supply network may be configured to route the respective clock signals such that a timing difference between the respective clock signals is protected from process, voltage and temperature (PVT) influences. Advantages, features and objects of the invention may include: (i) reducing a vulnerability of a circuit to clock skew induced by PVT characteristics; (ii) designing and/or placing a clock signal supply network based on a functional relationship between clocked cells; (iii) designing and/or placing a clock signal supply network based on an interconnectivity of clocked cells; (iv) designing and/or placing a clock signal supply network based on closely dependent timing relationships between cells; (iv) reducing (e.g., minimizing) a number of elements in clock paths to certain clocked cells; (v) increasing (e.g., maximizing) a common trunk portion of a clock supply network for driving certain clocked cells; and/or (vi) placing different clock paths physically close to each other to reduce PVT induced skew between the clock signals in the different clock paths. Other features, objects and advantages of the invention will become apparent from the following description, claims and/or drawings. BRIEF DESCRIPTION OF THE DRAWINGS Non-limiting preferred embodiments of the invention are now described, by way of example only, with reference to the claims and the accompanying drawings, in which: FIG. 1 is a flow diagram showing steps for placing a clock signal supply network using a design tool of a preferred embodiment of the invention; FIG. 2 is a schematic circuit diagram illustrating parts of a design of a first integrated circuit for which a clock signal supply network is to be prepared; FIG. 3 is a schematic circuit diagram similar to FIG. 2, and including a clock tree designed using the design tool of FIG. 1; FIG. 4 is a schematic circuit diagram similar to FIG. 2, and including a comparative example of a layout-based clock signal tree; FIG. 5 is a flow diagram showing steps for placing a clock signal supply network using a design tool of another preferred embodiment of the invention; FIG. 6 is a schematic circuit diagram illustrating parts of a design of a second integrated circuit for which a clock tree is to be prepared; FIG. 7 is a schematic circuit diagram similar to FIG. 6, and showing clock nodes and clusters derived by the design tool of FIG. 5; FIG. 8 is a schematic circuit diagram similar to FIG. 6, and including a clock signal supply network generated by the design tool of FIG. 5; and FIG. 9 is a schematic circuit diagram similar to FIG. 6, and including a comparative example of a layout-based clock tree. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 may illustrate execution steps used in a design tool (e.g., clock placement tool) 14 of a preferred embodiment of the invention. The design tool 14 may be configured to design a clock signal supply network (e.g., a clock tree) for a first circuit layout (e.g., circuit 10 in FIG. 2) for an integrated circuit 12. The design tool 14 may be computer-based. The steps may be executed on and/or by a computer. The design tool 14 may be configured to provide a balanced and/or optimized clock tree for demanding and/or speed critical circuits. The design tool 14 may take account of one or more of process, voltage and temperature (PVT) characteristics. The design tool 14 may route the clock signals to certain cells, so as to protect a relative timing of the clock signals from PVT characteristics. PVT characteristics may affect the speed and/or timing of circuitry at different locations within an integrated circuit 12. PVT characteristics may affect the speed at which circuit elements (e.g., active circuit elements) may operate. For example, PVT characteristics may affect the operating speed of repeater cells (78 described later) used in a clock tree. PVT characteristics may introduce clock skew when the PVT characteristics may be different in different branches of the clock tree and/or when the PVT characteristics affect different branches of the clock tree differently. The manner in which PVT characteristics may affect different branches of a clock tree may be difficult to control and/or predict. Process characteristics may include minor processing variations that may occur during fabrication of the integrated circuit 12. Minor processing variations may occur between different integrated circuits 12, or at different locations within an integrated circuit 12. Minor processing variations may, for example, include a doping level or gradient. Voltage characteristics may include voltage drops occurring while the integrated circuit 12 is in use, or an allowable voltage range over which the integrated circuit 12 may be specified for use. Temperature characteristics may include an allowable operating temperature range for the integrated circuit as a whole, or hot-spots generated at localized areas of the integrated circuit, creating a temperature gradient. The voltage and/or the temperature characteristics may vary dynamically when the integrated circuit is in use. The design tool 14 may be configured to place a clock tree to reduce a vulnerability to PVT induced clock skew for at least certain cells. The design tool 14 may take into account the connectivity and/or timing paths of cells. The design tool 14 may design a clock tree such that cells having a closely dependent timing are supplied with a clock signal from the same portion (e.g., branch) of the clock tree as one another. FIG. 2 may illustrate an example portion of a design of a circuit 10 for the integrated circuit 12, for which a clock tree (not shown in FIG. 2) is to be designed by the design tool 14. The integrated circuit 12 may, for example, be an Application Specific Integrated Circuit (ASIC). The circuit 10 is merely an example to illustrate the operation of the design tool 14. Other circuits may include different functional circuit cells and/or interconnections according to specific design criteria. The circuit 10 may include a clocked cell 20 at a first location, and a downstream clocked cell 22 at a second location. An output signal 26 from the clocked cell 20 may be coupled to an input 28 of the downstream clocked cell 22. The output signal 26 may be coupled to the input 28 via combinatorial logic 24. The circuit 10 may additionally or alternatively include a clocked cell 30 at a third location, and a downstream clocked cell 32 at a fourth location. An output signal 34 from the clocked cell 30 may be coupled to an input 36 of the downstream clocked cell 32. The output signal 34 may be coupled directly to the input 36. The first location may be near or at the third location. The second location may be near or at the fourth location. The circuit 10 may additionally include one or more other clocked cells 38 (e.g., 38a and 38b) near the first to fourth locations. The circuit 10 may include other functional connections, but only certain timing critical interconnections for the portion of the circuit 10 are illustrated in FIG. 1. The clocked cells 20, 22, 30, 32 and 38 may be any type of circuit having an input (e.g., CLK) for receiving a clock signal for triggering and/or clocking and/or controlling the timing of the cell. For example, one or more of the clocked cells 20, 22, 30, 32 and 38 may be a flip flop. The clocked cells 20, 22, 30, 32 and 38 may be clocked by a clock signal 40 derived from a common clock source 41, and supplied by a clock tree to be designed. Referring to FIGS. 1, 2 and 3, the design steps may include a step 50 at which the cells (e.g., 20, 22, 30, 32 and 38) are placed in the physical layout of the integrated circuit 12. The step 50 may be carried out previously as part of a different design process, or it may be conducted by the design tool 14. At a next step 52, the tool 14 may perform a first analysis to identify one or more clusters of cells that have a closely dependent timing. A closely dependent timing may be determined for cells when a timing of one cell (e.g., 20 or 30) may affect the timing of a downstream cell (e.g., 22 or 32) that receives a signal derived from the one cell. The step 52 may be performed by analysing the connectivity of cells and/or analysing a relative timing relationship amongst the cells. Additionally or alternatively, a user or designer may specify specific cells that may be in a timing critical or speed critical path. The step 52 may define clusters based on such user or designer specified information. For the circuit 10, the step 52 may identify a cluster 54. The cluster 54 may comprise the cell 20 and the downstream cell 22. The cluster 54 may be identified because the timing of the downstream cell 22 may be dependent on the timing of the cell 20 (e.g., with a delay as a result of the combinatorial logic 24). The step 52 may additionally or alternatively identify a cluster 56. The cluster 56 may comprise the cell 30 and the downstream cell 32. The cluster 56 may be identified because the timing of the downstream cell 32 may be directly dependent on the timing of the cell 30. At a next step 58, the tool 14 may perform a second analysis to identify other cells 38 (e.g. 38a and 38b) that may be located near the clusters 54 and 56. At a next step 60, the clusters 54 and 56 may be expanded to include not only the cells having a closely dependent timing, but also the other cells 38 nearby. For example, the cluster 54 may be expanded (at 54a) to include the cell 38a, and the cluster 56 may be expanded (at 56a) to include the cell 38b. At a next step 62, a clock tree 72 may be generated for supplying one or more clock signals to each cluster 54 and 56. The clock signals may originate from the clock signal source 41. The clock signal source 41 may, for example, comprise a driver or buffer for applying the clock signal. For example, a branch 70 of the clock tree 72 may be generated for supplying the clock signal from the clock signal source 41 to the cluster 54 and/or the expanded cluster 54a. Also for example, a branch 76 of the clock tree 72 may be generated for supplying the clock signal from the clock signal source 41 to the cluster 56 and/or the expanded cluster 56a. The step 62 may be performed separately for each cluster, or for a plurality of the clusters in combination as a group. The step 62 may comprise recursive sub-steps 64 and 66. The sub-step 64 may comprise inserting a repeater cell 78 in a respective branch of the clock tree 72, working backwards from the or each respective cluster 54, 56 towards the clock signal source 41. The repeater cell 78 may include one or more circuit elements, for example, active circuit elements. The repeater cell 78 may typically be an inverter and/or a buffer. The sub-step 66 may comprise determining whether or not the clock signal source 41 is sufficiently powerful to drive the last-inserted repeater cell 78 without risking a loss in the level (e.g., voltage level) and/or timing (e.g., slew rate) of the clock signal 40. When at the sub-step 66 it is determined that the clock signal source 41 is not sufficiently powerful, the process may loop back to the sub-step 64 for inserting another repeater cell 78 in the or each branch. When at the sub-step 66 it is determined that the clock signal source 41 is sufficiently powerful, the process may terminate (e.g., at a step 68). The sub-step 64 may also comprise inserting a delay compensation cell 80 into one or more of the branches 70 and 76 to compensate for signal delays between an upstream cell and a downstream cell. For example, the delay compensation cell 80 may be inserted in the branch 70 between the cell 20 and the downstream cell 22, in order to compensate for a propagation delay of the combinatorial logic 24. The propagation delay may be a time duration taken by the output signal 26 propagating through the combinatorial logic 24 to the input 28 of the downstream cell 22. A feature of the clock tree 72 designed by the design tool 14 may be that cells (e.g., 20 and 22; 30 and 32) that have a closely dependent timing, may be supplied by substantially the same branch or portion of the clock tree. Using the same branch of the clock tree may optimize the timing of a clock signal for driving the closely dependent cells, and reduce the risk of clock skew caused by PVT differences affecting different clock tree branches. A clock signal supplied two different cells via the same branch may show much less PVT induced skew compared to the same clock signal being supplied by two different branches. A further feature may be that a number of cells (e.g. repeater cells 78 and/or compensation cells 80) on a clock signal path between cells having a closely dependent timing may be small (e.g., no more than 5, or no more than 4, or no more than 3, or no more than 2, or no more than 1, or zero). FIG. 4 may illustrate a comparative example of a clock tree 42 that may be designed for the circuit 10 using only layout-based design techniques (e.g., without taking account of PVT characteristics). The clock tree 42 may include a branch 44 and a branch 46. However, in a layout based clock tree 42, the branches 44 and 46 are designed to supply the clock signal to different local areas of the integrated circuit 12 without taking account of any cell interconnectivity. For example, the branch 44 may supply the clock signal to the first and third locations, especially when these locations are close to each other. The branch 46 may supply the clock signal to the second and fourth locations, especially when these locations are close to each other. Repeater cells 48 may be arranged in the branches 44 and 46 to preserve the clock signal on long signal paths in the branches 44 and 46, in a similar manner to the repeater cells 78. The branches 44 and 46, and the number of repeater cells 48 in each branch, may be designed such that a theoretical signal path length in each branch 46 is the same. However, the clock tree 42 of FIG. 4 may suffer serious disadvantages compared to the clock tree 72 of FIG. 3. In either Figure, clock skew may be introduced between the clock signals in the branches 70 and 76, or 44 and 46, respectively. The clock skew may be induced by PVT characteristics, which may affect the repeater cells 78 and 48 in each branch differently. With the clock tree of FIG. 4, clock skew between the branches 44 and 46 may cause timing violations between the clocked cell 20 and the downstream clocked cell 22 and/or between the clocked cell 30 and the downstream clocked cell 32. The timing violations may arise because the closely dependent pairs of cells 20 and 22, or 30 and 32, are clocked by different branches of the clock tree 42. In contrast, the clock tree of FIG. 3 may enable the circuit 10 to tolerate clock skew between the branches 70 and 76 without the same vulnerability to timing violations. At least a degree of clock skew may be tolerated because the cells that are closely timing dependent may be driven by the same branch or portion of the clock tree. Clock skew between the branches 70 and 76 may not affect the timing of cells driven by the same branch. FIG. 5 may illustrate execution steps of a second embodiment of design tool 100 for performing a similar function to the design tool 14. FIGS. 6-8 may illustrate a portion of a circuit 102 to which the design tool 100 may be applied to design and/or place a clock tree. As with the circuit 10, the circuit 102 is merely an example to illustrate the operation of the design tool 100. Other circuits may include different functional circuit cells and/or interconnections according to specific design criteria. The circuit 102 may, for example, comprise a plurality of clockable circuit cells 104 (e.g., fifteen clockable circuit cells 104a-o). The clockable circuit cells 104 may be any type of cell having an input for receiving a clock signal for controlling a timing of the cell 104. For example, the cells 104 may be flip-flops, latches, memories, etc. One or more of the cells 104 (e.g. a downstream cell 104d, 104f, 104k and 104m) may have an input coupled to receive a signal derived from, or directly or indirectly responsive to, an output of one or more other of the cells 104 (e.g. an upstream cell 104c, 104e, 104j and 104m, respectively). Combinatorial logic 106 may be coupled between one or more of the upstream cells 104c, 104e, 104j and 1041, and the respective downstream cells 104d, 104f, 104k and 104. Each of the cells 104 may receive one of a plurality of clock signals 108 (e.g., four clock signals 108a-d). The clock signals 108 may be derived from a master clock signal 110 by clock circuitry represented functionally by a circuit block 112. For example, the circuit block 112 may comprise one or more of an inverter 114, logic 116 and 118, a gate 120, and a multiplexer 122, for generating the four different clock signals 108a-d. The circuit block 112 is merely an example to illustrate that a variety of different clock signals 108 may be distributed to different ones of the cells 104. Referring to FIG. 5, the design tool 100 may be configured to implement the circuit block 112 as a clock tree (124 in FIG. 8). The design tool 100 may be configured to take account of PVT characteristics. The design tool 100 may be configured to design the clock tree 124 taking account of a close timing dependency between certain ones of the cells 104 and/or taking account of a connectivity between certain ones of the cells 104. The design tool 100 may comprise a step 130 of identifying timing dependent paths in the circuit 102. The step 130 may identify critical and/or closely dependent timing paths in which the timing of one of the cells 104 may be closely dependent on the timing of another of the cells 104. For example, the step 130 may identify timing dependent paths by analysing the connectivity between the cells 104 and/or by a timing analysis. Additionally or alternatively, a user or designer may identify specific timing dependent paths that may be considered timing critical for achieving a desired operating speed of the circuit 102. The step 103 may, for example, identify four time dependent paths 132a-d in the circuit 102 associated with the interconnections between the four upstream cells 104c, 104e, 104j and 1041, and the four downstream cells 104d, 104f, 104k and 104m. At a step 134, an analysis of the time dependent paths 132a-d may be performed to identify the start and/or end points of each time dependent path 132. For example, the step 134 may determine a respective upstream cell and/or a respective downstream cell associated with each time dependent path. For the time dependent path 132a, the step 134 may determine the start point to be the cell 104c, and the end point to be the cell 104d. For the time dependent path 132b, the step 134 may determine the start point to be cell 104e, and the end point to be the cell 104f. For the time dependent path 132c, the step 134 may determine the start point to be the cell 104j, and the end point to be the cell 104k. For the time dependent path 132d, the step 134 may determine the start point to be the cell 1041, and the end point to be the cell 104m. The cells 104 at the start and/or end points may be referred to as “critical” cells, because carefully timed clock signals may be appropriate to avoid timing violations. At a step 136, an analysis of the circuit block 112 may be performed. The step 136 may analyze the circuit block 112 to determine, for each time dependent path 132a-d, a respective clock node 138a-d (FIG. 7). The clock node 138a-d may be a node that is common to the start and end points of the respective time dependent path 132a-d. Step 136 may perform the analysis by tracking back the clock signals applied to the start and end points of the respective time dependent path 132 to identify the clock node 138. At a step 140, a respective cluster 142a-d (FIG. 7) may be defined for each time dependent path 132a-d and/or clock node 138a-d. The cluster 142 may include the start and end point cells among the plurality of cells 104. The cluster 142 may include all of the clockable cells 104 that may be associated with the respective time dependent path 132. The cluster 142 may include the respective clock node 138 associated with the respective time dependent path 132. At a step 144, the clock nodes 138a-d and the associated clusters 142 may be processed. The step 144 may process the clock nodes 138a-d to assemble the clock tree 124. The step 144 may process the clock nodes 138a-d hierarchically. The step 144 may process one or more deepest clock nodes 138a-d first. A deepest clock node may be a node that is furthest from the master clock signal 110. For example, in the circuit 102, the clock nodes may be processed in an order of 138a, 138b, 138c and 138d. In particular, the clock node 142a and/or the clock node 142c may be processed before the clock node 138b. The step 144 may comprise one or more sub-steps 146, 148, 150 and 158. The sub-step 146 may be carried out when no combinatorial logic may be configured in the circuit block 112 between the respective clock node 138 and the start and end point cells associated with the respective cluster 142. The sub-step 146 may comprise inserting a clock sub-tree 152 to interconnect the node 138 and the start and end cells. For example, referring to FIG. 8, clock sub-trees 152a and 152c may be inserted for the clusters 142a and 142c. The clock sub-trees 152 may include one or more repeater cells 153. The repeater cell(s) 153 may be inserted preferentially in a common (e.g., trunk) portion 155 of the respective sub-tree 152a and 152c, in preference to a divided (e.g., branch) portion (indicated by arrows 170a and 170c). Placing the repeater cell(s) 153 in the common portion 155 instead of the divided portions 170a and 170c may reduce a risk of PVT induced clock skew between the branch portions. The sub-step 148 may be carried out when combinatorial logic may be configured in the circuit block 112 between the respective clock node 138 and the start and end point cells associated with the respective cluster 142. The sub-step 148 may comprise duplicating a functional structure of the associated portion of the circuit block 112. The functional structure may be duplicated to an extent that no additional buffering may be appropriate. For example, referring to FIG. 8, portions 154b and 154d duplicating a functional structure of portions 156b and 156d may be inserted for the clusters 142b and 142d. The portions 154b and 154d may duplicate the functional structure of portions of the circuit 112 from which the respective clock signals 108a and 108c are derived. Duplicating the functional structure may involve additional circuitry overhead. However, the costs of additional circuitry overhead may be significantly outweighed by advantages of reducing PVT induced clock skew. One or more repeater cells 153 may also be included to preserve an integrity of the clock signal in long signal paths. The sub-step 150 may relate to fine-tuning placement of elements in the clock paths to a respective cluster 142 when the clock paths to the cells in the cluster 142 may differ. For example, clusters 142b and 142d contain a plurality of clock paths, including a first clock path for the respective start point cell, and a second clock path for the respective end point cell. The step 150 may comprise placing elements on the plural clock paths close to one another. In particular, the portions 154b and 154d may be located close to the other clock paths in the clusters 142n and 142d, respectively. Such placement may minimize or at least reduce PVT induced variation between the clock paths. The sub-step 158 may comprise identifying other cells amongst the plurality of cells 104 that are driven by the respective clock node 138. One or more further clock sub-trees 160 may be inserted for supplying the clock signal from the respective node 138 to those other cells. A step 162 may be performed for fine-tuning placement of certain ones of the cells 104 to reduce PVT induced variations between the cells 104. The step 162 may comprise placing cells 104 that are in the same respective cluster 142 physically close to one another in the integrated circuit layout. A step 164 may be performed for fine-tuning placement of the clock tree 124, to further reduce PVT induced variations in the clock signals. The step 164 may be similar to the step 150 described above. The step 164 may relate to elements on plural clock paths for supplying clock signals to closely time dependent cells. The step 164 may comprise placing elements on the plural clock paths close to one another. Such placement may minimize or at least reduce PVT induced variation between the clock paths. In FIG. 8, arrows 170a-d may illustrate respective pairs of the cells 104 between which the clock signal may be optimized to have a low skew, and a low vulnerability to PVT characteristics. The arrows 170a and 170c may indicate substantially no elements in different clock paths. The arrows 170b and 170d may indicate clock paths which have different elements, but which are configured to closely match each other, and be located physically close to each other, to minimize PVT effects. The clock paths indicated by the arrows 170a-d may generally have a long common trunk and/or short branches and/or may include a low (e.g., minimum) number of elements differing in the clock paths for driving cells in each cluster 142. FIG. 9 may illustrate a comparative example of a clock tree 180 that may be designed for the circuit 102 using only layout-based design techniques (e.g., without taking account of PVT characteristics). The clock tree 180 may generally resemble the circuit block 112 (of FIG. 6), but with additional repeater cells 182 to distribute the clock signals 108a-d across the circuit 102, and to preserve the clock signals 108a-d in long signal paths. Arrows 184a-d may indicate clock paths for pairs of the cells 104 that are closely time dependent. However, in contrast the clock tree 124 of FIG. 8, the clock tree 180 may be significantly more vulnerable to PVT effects. For example, the arrows 184a and 184c indicate clock paths that include different repeater cells 182 in the clock paths to the respective cells 104. Such different repeater cells 182 are vulnerable to different PVT effects, and are likely to result in PVT induced clock skew. The arrows 184b and 184d indicate pairs of clock paths that are significantly different, and extend largely over different branches of the clock 180. Clock paths in different branches are vulnerable to PVT induced clock skew. The functions performed by the flow diagrams of FIGS. 1 and 5 may be implemented using a conventional general purpose digital computer programmed according to the teachings of the present specification, as will be apparent to those skilled in the relevant art(s). Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant art(s). The present invention may also be implemented by the preparation of ASICs, FPGAs, or by interconnecting an appropriate network of conventional component circuits, as is described herein, modifications of which will be readily apparent to those skilled in the art(s). The present invention thus may also include a computer product which may be a storage medium including instructions which can be used to program a computer to perform a process in accordance with the present invention. The storage medium can include, but is not limited to, any type of disk including floppy disk, optical disk, CD-ROM, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, Flash memory, magnetic or optical cards, or any type of media suitable for storing electronic instructions. The present invention may also include a storage medium including a representation of design data of a circuit and/or slice and/or die in accordance with the present invention. The design data may be a representation prior to customization and/or after customization. The design data may include a representation of custom-specific layers and/or custom-independent layers. The design data may be data for fabrication. The storage medium can include, but is not limited to, any type of disk including floppy disk, optical disk, CD-ROM, magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, Flash memory, magnetic or optical cards, or any type of media suitable for storing electronic instructions. While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the sprit and scope of the invention. | <SOH> BACKGROUND TO THE INVENTION <EOH>One of the steps of designing an integrated circuit layout is to arrange for clock signals to be supplied to clocked cells of the circuit. A computer based design tool is used to automatically design a clock signal supply network (clock tree) according to predetermined design rules. The clock tree has multiple branches to deliver clock signals to different circuit cells, at different locations, on an integrated circuit die. The branches typically include active circuit cells through which the clock signal passes. Typical active cells include repeater cells for preserving the clock signal in long signal paths, and clock gate cells for selectively blocking or applying the clock signal. In a balanced clock tree, the branches are designed to have generally the same signal path length in each branch in an attempt to reduce clock skew between the branches. Controlling clock skew is an important part of the design process. Clock skew affects the relative timing at which different cells in the integrated circuit operate. Clock skew can be a limiting factor on the maximum operating speed of one or more parts of the integrated circuit or the integrated circuit as a whole. In practice, undesirable clock skew between two or more branches of a clock tree remains a significant design problem. The problem is becoming increasingly apparent as greater demands are made on speed, performance, complexity and fabrication size and density of integrated circuits. Current automatic design tools for placing clock trees lack sufficient refinement for optimizing clock trees in demanding or speed critical designs. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention may relate to a method of placing a clock signal supply network in a design representation for an integrated circuit. The design representation may comprise a plurality of clockable circuit cells. The method may comprise identifying a first of the clockable circuit cells in the design representation. The method may further comprise identifying a second of the clockable circuit cells in the design representation. The second clockable circuit cell may have a clock timing dependent relation relative to the first clockable circuit cell. The method may further comprise configuring the clock signal supply network. The clock signal supply network may be configured to supply respective clock signals to the first and said second clockable circuit cells. The clock signal supply network may be configured to route the respective clock signals such that a timing difference between the respective clock signals is protected from process, voltage and temperature (PVT) influences. Advantages, features and objects of the invention may include: (i) reducing a vulnerability of a circuit to clock skew induced by PVT characteristics; (ii) designing and/or placing a clock signal supply network based on a functional relationship between clocked cells; (iii) designing and/or placing a clock signal supply network based on an interconnectivity of clocked cells; (iv) designing and/or placing a clock signal supply network based on closely dependent timing relationships between cells; (iv) reducing (e.g., minimizing) a number of elements in clock paths to certain clocked cells; (v) increasing (e.g., maximizing) a common trunk portion of a clock supply network for driving certain clocked cells; and/or (vi) placing different clock paths physically close to each other to reduce PVT induced skew between the clock signals in the different clock paths. Other features, objects and advantages of the invention will become apparent from the following description, claims and/or drawings. | 20040709 | 20061003 | 20060112 | 81233.0 | G06F1750 | 0 | PARIHAR, SUCHIN | PLACEMENT OF A CLOCK SIGNAL SUPPLY NETWORK DURING DESIGN OF INTEGRATED CIRCUITS | UNDISCOUNTED | 0 | ACCEPTED | G06F | 2,004 |
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10,887,617 | ACCEPTED | Method and apparatus for controlled persistent ID flag for RFID applications | A Radio-Frequency Identification (RFID) transponder is provided. The RFID transponder may include a basic ID flag circuit having a VDD voltage node, an output voltage node, and a capacitor coupled to the VDD voltage node and the output voltage node to store an ID flag. A supplemental discharge current circuit coupled to the basic ID flag circuit is provided in order to control persistence duration of the state of the ID flag. The persistence duration of the state of the ID flag is controlled by maintaining supplemental discharge current, which is greater than the leakage current of the basic ID flag circuit. | 1. A Radio-Frequency Identification (RFID) transponder including: an identification flag circuit to maintain an RFID transponder state, the identification flag circuit including a first capacitor and a digital element coupled to the first capacitor to receive a voltage of the first capacitor; and a discharge circuit to drain the first capacitor via a discharge current that is distinct from a semiconductor leakage current. 2. The RFID transponder of claim 1, further including a charge circuit, wherein the semiconductor leakage current is through an open switch of the charge circuit. 3. The RFID transponder of claim 1, wherein the digital element is a comparator, the comparator being to output a signal indicative of the identification flag. 4. The RFID transponder of claim 1, wherein the discharge circuit is to maintain the discharge current substantially constant with temperature. 5. The RFID transponder of claim 1, wherein the ID flag circuit further includes a leakage circuit to allow a leakage current to discharge the capacitor in addition to the discharge current. 6. The RFID transponder of claim 1, wherein the discharge current decreases with temperature. 7. The RFID transponder of claim 1, wherein the discharge current is higher than the semiconductor leakage current. 8. The RFID transponder of claim 1, wherein the discharge current is lower than the semiconductor leakage current. 9. The RFID transponder of claim 1, wherein the discharge circuit includes: a discharge circuit capacitor to store voltage; and a transconductor circuit coupled to the discharge circuit capacitor to convert voltage stored on a discharge circuit capacitor into the discharge current. 10. The RFID transponder of claim 9, wherein the transconductor circuit includes: a first transistor having a gate, a source and a drain, the gate coupled to the discharge circuit capacitor; and a second transistor having a gate, a source and a drain the gate coupled to the discharge circuit capacitor. 11. The RFID transponder of claim 10, wherein the discharge circuit capacitor is to store the gate voltage of the first transistor and the gate voltage of the second transistor responsive to detection of power loss on the RFID transponder. 12. The RFID transponder of claim 10, wherein the first transistor and the second transistor are NMOS transistors. 13. The RFID transponder of claim 10, wherein a W/L ratio of the second transistor is smaller than a W/L ratio of the first transistor. 14. The RFID transponder of claim 9, wherein the discharge circuit includes a discharge circuit switch coupled to the discharge circuit capacitor and adapted to open responsive to detection of power loss on the RFID transponder. 15. The RFID transponder of claim 1, further including a digital non-volatile memory to control accuracy of the discharge current. 16. The RFID transponder of claim 1, further including an output voltage node coupled to the digital element, the output voltage node indicating an identification flag state. 17. The RFID transponder of claim 16, wherein the identification flag state persists during a power loss at the RFID transponder for a predetermined period of time. 18. The RFID transponder of claim 16, wherein the predetermined period of time is more than or equal to 500 milliseconds. 19. The RFID transponder of claim 16, wherein the predetermined period of time is less than or equal to 20 seconds. 20. The RFID transponder of claim 16, wherein the identification flag state persists during a power loss at the RFID transponder for the predetermined period of time at temperatures between negative 25 degrees Celsius and 50 degrees Celsius. 21. The RFID transponder of claim 16, wherein the identification flag state is represented by a single bit. 22. A method to control persistence of an RFID transponder state, comprising: charging to a supply voltage a capacitor operative to indicate the RFID transponder state; and draining the capacitor with a discharge current distinct from a semiconductor leakage current from an open switch. 23. The method of claim 22, wherein the capacitor is charged responsive to responding to an interrogation signal. 24. The method of claim 22, further comprising: additionally draining the capacitor with the semiconductor leakage current. 25. The method of claim 22, wherein the discharge current is higher than the semiconductor leakage current. 26. The method of claim 22, wherein the discharge current is lower than the semiconductor leakage current. 27. The method of claim 22, wherein the RFID transponder state persists during a power loss at the RFID transponder for a predetermined period of time. 28. The method of claim 27, wherein the predetermined period of time is more than or equal to 500 milliseconds. 29. The method of claim 27, wherein the predetermined period of time is less than or equal to 20 seconds. 30. The method of claim 27, wherein the RFID transponder state persists during a power loss at the RFID transponder for the predetermined period of time at temperatures between negative 25 degrees Celsius and 50 degrees Celsius. 31. The method of claim 22, wherein the RFID transponder state is represented by a single bit. 32. A device to control persistence of an RFID transponder state, comprising: means for charging to a supply voltage a capacitor operative to indicate the RFID transponder state; and means for draining the capacitor with a discharge current distinct from a semiconductor leakage current from an open switch. 33. The device of claim 32, wherein the capacitor is charged responsive to responding to an interrogation signal. 34. The device of claim 32, further comprising: means for additionally draining the capacitor with the semiconductor leakage current. 35. The device of claim 32, wherein the discharge current is higher than the semiconductor leakage current. 36. The device of claim 32, wherein the discharge current is lower than the semiconductor leakage current. 37. The device of claim 32, wherein the RFID transponder state persists during a power loss at the RFID transponder for a predetermined period of time. 38. The device of claim 37, wherein the predetermined period of time is more than or equal to 500 milliseconds. 39. The device of claim 37, wherein the predetermined period of time is less than or equal to 20 seconds. 40. The device of claim 37, wherein the RFID transponder state persists during a power loss at the RFID transponder for the predetermined period of time at temperatures between negative 25 degrees Celsius and 50 degrees Celsius. 41. The device of claim 32, wherein the RFID transponder state is represented by a single bit. | RELATED APPLICATIONS The present application is related to, incorporates by reference and hereby claims the priority benefit of the following U.S. Provisional Patent Application, assigned to the assignee of the present application: U.S. Provisional Patent Application No. 60/562,154, filed Apr. 13, 2004, entitled “Method and Apparatus for Controlled Persistent ID Flag for RFID Applications”. FIELD OF THE INVENTION One exemplary embodiment relates generally to the field of Radio Frequency Identification (RFID) transponders (e.g., RFID tags) and more specifically to a method and apparatus for controlled persistent ID flag for RFID applications. BACKGROUND OF THE INVENTION Radio Frequency Identification (RFID) tags are used in a multiplicity of ways. They may be used in locating and identifying accompanying objects, as well as for transmitting information about the state of an object. It has been known since the early 60's that electronic components of transponders could be powered by a sequence of periodic signal bursts sent by a reader (or interrogator) and received by a tag antenna on each of the transponders. The RF electromagnetic field induces an alternating current in the transponder antenna that can be rectified by a RF diode of the transponder. The rectified current can be used for a power supply for the electronic components of the transponder, and enables the transponder to broadcast a return signal without itself having a self-contained power supply. An illustrative cycle of a prior art operation of an array of ten RFID tags may be described as follows: 1. The base station or the reader is on channel one and RFID tags 1-8 respond by beginning their participation in the identification protocol. All eight tags are successfully identified. 2. The reader now hops to channel 2, and the frequency of channel 2 allows tags 7-9 to be powered. Tag 9 will now respond by beginning participation in the identification protocol, while tags 1-6 lose their power and therefore stop participating. Since tags 7 and 8 were already identified and continue to be powered sufficiently when operating on channel, they do not participate in the protocol. 3. The reader hops to channel 3. The frequency of channel 3 allows tags 2-10 to be powered. Tags 7-9 stay powered and do not participate in the protocol. However, tags 2-6 must be reidentified in order to identify the one truly new tag 10. The RFID tags that are not well powered lose track of state information. This state information is essentially a bookmark in the communication sequence between the RFID tag and the base station. In running an ID protocol, for example, tags that newly enter the field, as well as tags that have lost power and then regained it while remaining in the field, are treated equally (i.e. tags that have lost power and regained it may be identified a second time). This process of again identifying an RFID tag that has previously been identified is, of course, inefficient. U.S. Pat. No. 6,404,325 (Heinrich et. al.) is directed at maintaining the integrity of state information retained by a Radio Frequency Transponder during a loss of power. In Heinrich, the state information is maintained by a mirror latches mechanism and a capacitor utilized as a power source for the mirror latches mechanism during the interval when the power supply to the RFID tag is interrupted. The time interval during which the mirror latches mechanism retains the state information (persistence of state) depends on the size of the capacitor. Persistence of state is also determined by the leakage current from the capacitor. Of course, leakage may be primarily due to switches connected to the capacitor and not through the capacitor itself. The switches are open, and so only semiconductor leakage current flows through them. Because the leakage current may vary with temperature, an RFID tag with a certain size capacitor may not retain state information as long as necessary at high temperatures and retain state information longer than is practicable at low temperatures. SUMMARY OF THE INVENTION According to one aspect, there is provided a Radio-Frequency Identification (RFID) transponder including an identification flag circuit to maintain a state of the identification flag indicating that the RFID transponder has responded to an interrogation signal, the identification flag circuit including a first capacitor and a digital element coupled to the first capacitor to receive a voltage of the first capacitor; and a discharge circuit to drain the first capacitor via a discharge current that is distinct from a semiconductor leakage current. According to another aspect, the RFID transponder includes an additional charge circuit, wherein the semiconductor leakage current is through an open switch of the charge circuit. According to yet another aspect, the digital element is a comparator, the comparator being to output a signal indicative of the identification flag. According to a further another aspect, the discharge circuit is to maintain the discharge current substantially constant with temperature. Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated by way of example and not limited in the figures of the accompanying drawings, in which like references indicate similar elements and in which: FIG. 1 is a block diagram of components of an RFID tag, according to one exemplary embodiment of the present invention. FIG. 2 is a block diagram of the analog front end of an RFID tag, according to one exemplary embodiment of the present invention. FIGS. 3A, 3B and 3C are schematic diagrams of a basic ID flag circuit. FIG. 3D is a diagram illustrating behavior of a basic ID flag circuit. FIG. 4A illustrates an enhanced ID flag circuit, according to one exemplary embodiment of the present invention. FIG. 4B illustrates an enhanced ID flag circuit, according to another embodiment of the present invention. FIG. 5 is a diagram illustrating the dependence of the ID flag persistence duration on the temperature for an enhanced ID flag circuit, according to one exemplary embodiment of the present invention. FIG. 6 is a schematic diagram illustrating an implementation of a supplemental discharge current circuit, according to one exemplary embodiment of the present invention. FIG. 7 is a schematic diagram to show an exemplary embodiment of a charge and leakage circuit within the enhanced ID flag circuit, according to one exemplary embodiment of the present invention. FIG. 8 includes time/voltage diagrams for the enhanced ID flag circuit, according to one exemplary embodiment of the present invention. DETAILED DESCRIPTION A method and apparatus to implement a controlled persistent identification (ID) flag for RFID applications are described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention may be practiced without these specific details. Because passive RFID tags do not have an independent source of power, it may be desirable that the tag state can be maintained during the temporary power loss (e.g., when the RFID tag is no longer illuminated by an interrogator RF signal). Passive RFID tags receive power from an RF link. An RF link may not be reliable and thus temporary power drops are not uncommon. The following scenario may illustrate a situation that an ID flag or persistent storage bit is intended to address. Consider a population of tags, for example, affixed to a number of cases of merchandise in a delivery truck. An employee is scanning these cases of merchandise (effectively, the tags) with an RFID reader (or interrogator) device in order to count them. The process of scanning and counting the tags may include the reader sending an RF signal to the tags via a forward link and receiving a response from each of the tags via a backscatter link. It is desirable that the tags that have already been identified and counted by the reader do not respond to the reader, which may be accomplished by setting a state of an ID flag on the tag. While the RFID reader is in the process of scanning the tags, the power on some of the tags may drop in and out as the cases of merchandise move around and the RF fields change at each tag location. Another frequent cause of the power loss may be due to frequency hopping, pursuant to FCC or ETSI emissions requirements by the RFID reader. Every time there is a hop in frequency, there is a potential that a tag will lose power for an entire hop and not restore power again until the next hop. Such temporary loss of power may result in clearing the state of the ID flag, such that the tag will respond to the reader again, even though it has already been identified and counted. When the state of an ID flag is cleared during a temporary power loss, the reader will not make a counting mistake because each tag may be uniquely identified. However, the need to identify and count the tag, that has already been identified and counted, again would potentially increase the amount of time needed to scan the population of tags. Thus, it is desirable that the state of the ID flag persists during a temporary power loss. The duration of time for which an ID flag needs to persist is not very long, but enough to maintain the state of an ID flag during a temporary power outage. There may be a situation where it is desirable that the persistence of the state of an ID flag does not persist longer than a predetermined duration. An illustration of such situation is where a delivery truck arrives a warehouse and the truck driver goes into the back of this truck and takes a handheld reader (a first reader) and runs an inventory of all the goods to be transferred to the warehouse. In the process of scanning the goods (and the associated tags), the reader (the first reader) sets the states of the ID flags on all the tags. Then, a forklift drives up to the truck and then moves one pallet of goods into the warehouse, after which a warehouseman takes a reader (a second reader) and scans all the goods on the pallet. In this situation, if the state of the ID flags is still set (e.g., beyond a predetermined maximum duration), the second reader would not see the goods because the tags on the pallet do not respond to the second reader. Therefore, it is desirable that maximum persistence duration of the state of the ID flag be controllable. FIG. 1 is a block diagram of components of an RFID tag in the exemplary form of an RFID tag 100, according to one exemplary embodiment of the present invention. The RFID tag 100 may include a tag antenna 102, an analog front end 104, a digital controller 106, and a controlled persistence ID flag circuit 50. The controlled persistence ID flag circuit 50 provides stored state information (e.g., the state of the ID flag) to the digital controller 106. The state of the ID flag may indicate, for example, that the RFID tag 100 has responded to an interrogation signal, which may indicate that the item associated with the RFID tag has already been scanned. Similarly, the state of the ID flag may indicate, for example, that the RFID tag 100 has not responded to an interrogation signal, which may indicate that the item associated with the RFID tag has not yet been scanned. Within the analog front end 104, as shown in FIG. 2, there may be a rectifier 108, a demodulator 110, a modulator 112, and a Power Management Unit (PMU) 114. The rectifier 108 has an output of a VDD_rect voltage. The VDD_rect voltage is applied to the PMU 114. The PMU 114 converts the VDD_rect voltage into a regulated voltage VDD_reg. Both the VDD_rect voltage and the VDD_reg voltage are applied to the digital controller 106 and to the demodulator 110 within the analog front end 104. The PMU 114 may also generate a power on reset (“POR”) signal. The POR signal may be applied to a TRACK voltage node. FIGS. 3A and 3B are schematic diagrams of an ID flag circuit 10. Referring to FIG. 3A, the ID flag circuit 10 includes an input voltage node 22 coupled to VDD, a charge circuit 12 coupled to VDD, a leakage circuit 14, a first capacitor 16, a comparator 18, and an output voltage node 20. Referring to FIG. 3B, the charge circuit 12 includes a first switch 24 and a diode 26. The leakage circuit 14 includes a second switch 28. When the first switch 24 is closed and the second switch 28 is opened, the first capacitor 16 is charged through the diode 26. When the second switch 28 is closed and the first switch 24 is open, the first capacitor 16 is discharged and therefore the voltage on the output voltage node 20 is low. The voltage on the output voltage node 20 determines the state of the ID flag. The comparator 18 sets the output of the ID flag circuit 10 to “1” if the first capacitor 16 is charged up. As the first capacitor 16 discharges, the supply voltage may also be affected. At some point, the output of the first capacitor 16 drops to zero. In the power-off state, when VDD is low, both switches 24 and 28 are open, and therefore the charge on the first capacitor 16 is maintained even when the power is not present. Because the charge on the first capacitor 16 determines the state of the ID flag, the state of the ID flag is maintained even when the power is not present. The persistence of the state of the ID flag is determined by semiconductor leakage current through the diode 26 and the first switch 24 that could vary greatly with temperature. Because the semiconductor leakage current could vary greatly with temperature, the persistence of the ID flag state is not well controlled. For example, if a required minimum persistence is about 250 milliseconds at high temperature, then at low temperature where there is almost no leakage, the persistence may be in the order of minutes. This differential in leakage characteristics may present a problem in a two reader scenario provided above. FIG. 3C is a schematic diagram of an exemplary implementation of components of the ID flag circuit 10. The first switch 24 is implemented using a CMOS inverter; and the second switch 28 and the diode 26 are shown as NMOS devices. The diode 26 is shown as an NMOS diode. The diode 26 may be either a MOS diode or a pn diode. A MOS diode may have a lower “turn on” voltage and therefore may allow a lower supply voltage. However, when a sufficiently high supply voltage is available, then a regular pn junction diode may be appropriate. The fact that the leakage may be higher through a MOS diode than through a pn junction diode (and thus influence persistence time of the state of the ID flag) may determine the choice of a pn junction diode over a MOS diode. In an embodiment where a MOS diode is utilized, an NMOS diode is useful, because a PMOS diode has parasitic source and drain to N-well junction diodes that would become forward biased when VDD is low. FIG. 3D is a diagram illustrating dependence of the ID flag persistence duration and the leakage current on temperature. As is shown on FIG. 3D, the leakage current increases exponentially with the increase of temperature. The ID flag persistence duration, on the other hand, decreases exponentially with the increase of temperature because it depends in the inverse on the leakage current. When the temperature is T min, the ID flag persistence duration is at t max1; when the temperature is T max, the ID flag persistence duration is at t min1. Thus, in the ID flag circuit 10, the ID flag persistence duration varies significantly with temperature (e.g., t max1 over t min1 may be about a hundred, because the leakage current starts from very low values at reasonable temperatures). This problem may be addressed by introducing a supplemental discharge current circuit as shown in FIG. 4A. FIG. 4A illustrates an enhanced ID flag circuit 50-A, according to one exemplary embodiment of the present invention. The enhanced ID flag circuit 50-A includes the charge circuit 12, a capacitor 116, a digital element (e.g., a comparator 118), and a supplemental discharge current (SDC) circuit 30. The SDC circuit 30 is provided to address the difficulties present in the devices illustrated in FIGS. 3A-3D in controlling the persistence time of the ID flag state. FIG. 4B is another diagram of an enhanced ID flag circuit 50-B, according to another exemplary embodiment of the present invention. The enhanced ID flag circuit 50-B includes the charge circuit 12, the leakage circuit 14, the capacitor 116, the comparator 118, an output voltage node 120, and the SDC circuit 30. The SDC circuit 30 generates discharge current, which may be deliberately made larger than the leakage current at a predetermined range of temperatures (e.g., between negative 25 degrees Celsius and 50 degrees Celsius), so that even though the leakage may vary considerably with temperature, the persistence of the state of the ID flag is controlled by the sum of the discharge current and the leakage current. Since the discharge current dominates the variation in the leakage current at a predetermined range of temperatures, the leakage current does not cause a large variation of persistence of the state of the ID flag. It will be noted that the supplemental discharge current may be characterized as intentional discharge current as opposed to accidental leakage current. In one exemplary embodiment, desired minimum persistence duration may be 500 milliseconds, and desired maximum persistence duration may be 20 seconds. In one exemplary embodiment, the ID flag is implemented as a single bit. In one exemplary embodiment, a digital Non Volatile Memory (“NVM”) may be utilized to increase the accuracy of the discharge current. A calibration stage during factory test may be performed. The NVM may be used to control the size of the transistor that is connected to the second capacitor in creating the discharge current. FIG. 5 is a diagram illustrating the dependence of the ID flag persistence duration on the temperature for the enhanced ID flag circuit 50-B. As is shown in FIG. 5, the ID flag persistence duration in the enhanced ID flag circuit 50-B decreases more gradually with the increase of temperature as compared to the basic ID flag circuit 10 (see FIG. 3D). In FIG. 5, when the temperature is at T min, the ID flag persistence duration is at t max2; when the temperature is at T max, the ID flag persistence duration is at t min2. Thus, in the ID flag circuit 50-B, t max2 over t min2 may be about three, as opposed to a hundred, as shown in FIG. 3D. The total current affecting the persistence time equals the sum of the leakage current and the supplemental discharge current. In other words, the persistence of the state of the ID flag is controlled by the sum of the supplemental discharge current and the leakage current. In FIG. 5, the supplemental discharge current remains constant with temperature. It will be noted that in one exemplary embodiment of the present invention, the supplemental discharge current may decrease as the temperature increases, which may result in even less variation of the total current and thus in even less variation in the persistence time. FIG. 6 is a schematic diagram illustrating an implementation of the SDC circuit 30, according to one exemplary embodiment of the present invention. In FIG. 6, the SDC circuit 30 includes a second capacitor 32 to store voltage and a transconductor circuit 48 (e.g., a transistor) connected as a current source to convert the voltage stored in the second capacitor 32 into current. The second capacitor 32 may control a transistor, or a transconductor circuit 48, that generates the discharge current. Utilizing the second capacitor 32 may allow the discharge current to actually decrease with the increasing of temperature, thereby making the total current of FIG. 5 even less dependent on temperature and thus bringing t min2 even closer to t max2. The SDC circuit 30 may include a switch 34, coupled to a reference current (RC) voltage node 36, also coupled to a TRACK voltage node 38, and to the second capacitor 32. The transconductor circuit 48 may include a first NMOS device 40 and a second NMOS device 42, the first NMOS device 40 and the second NMOS device 42 coupled to the second capacitor 32 at a gate node 44. When power is provided to the enhanced ID flag circuit 50, a reference current is present and can be detected at an RC voltage node 36. When the reference current is present, the second switch 34 is closed, thus coupling the RC voltage node 36 to the second capacitor 32. The first NMOS device 40 therefore coupled to the second NMOS device 42 as an NMOS diode. The reference current is running through the first NMOS device 40 and setting up voltage at the gate node 44 proportional to the reference current on the first NMOS device 40. The second capacitor 32 is charged up to the voltage at the gate node 44. The first NMOS device 40 and the second NMOS device 42 together form a current mirror, where the W/L ratio of the second NMOS device 42 is smaller than the W/L ratio of the first NMOS device 40. The difference of the W/L ratio of the second NMOS device 42 and the W/L ratio of the first NMOS device 40 may be utilized to maintain the discharge current that is sufficiently small. For example, a reference current of one nano ampere may be running into the first NMOS device 40, whereas a discharge current of one or two pico amperes may be running out of the second NMOS device 42. When the enhanced ID flag circuit 50 stops receiving power, the switch 34 is opened. In one exemplary embodiment, the power management unit (PMU) 114 may be coupled to the SDC circuit 30, such that when a power drop below a predetermined threshold is detected at the TRACK voltage node 38, the switch 32 is opened. Because the switch 32 is opened when a power-off condition is detected, the second capacitor 32 maintains the charge accumulated at it, which facilitates maintaining the gate voltage of the first NMOS device 40 at the same level as the gate voltage of the second NMOS device 42 (which is the voltage at the gate node 44). Therefore, even though the reference current is no longer present, the first NMOS device 40 and the second NMOS device 42 both have the gate voltage present; and the second NMOS device 42 also has the drain voltage at a voltage node 46. The drain voltage on the second NMOS device 42 is the voltage stored on the first capacitor 16. Because the gate voltage of the second NMOS device 42 remains constant, the drain current of the second NMOS device 42, which is the discharge current, also remains constant even when the power is not present. Because the discharge current is required to be small, the W/L ratio of the second NMOS device 42 is much smaller than the W/L ratio of the first NMOS device 40. FIG. 7 is a schematic diagram to show an exemplary embodiment of a charge and leakage circuit 60, where an NMOS switch 68 is used instead of the first switch 24 and the diode 26 (see FIG. 3C). The charge and leakage circuit 60 may be included in the enhanced ID flag circuits 50-A, 50-B, as well as in the basic ID flag circuit 10 of FIG. 3A. In FIG. 7, the persistence duration is controlled by controlling the voltage on the first capacitor 16. The accuracy with which persistence duration of the state of the ID flag is controlled may depend on how accurately the voltage on the first capacitor 16 is controlled. For example, if the voltage that is stored on the first capacitor 16 varies due to temperature, then it will take longer to discharge the first capacitor 16 when the temperature is higher than when the temperature is lower. The forward voltage of an NMOS diode (e.g., the NMOS switch 68) varies with temperature, which may cause variation in the stored voltage at different temperatures. The drain of the NMOS switch 68, which corresponds to a voltage node 62, may be controlled by a CMOS inverter 64 in order to keep the leakage current low when an ID flag circuit (e.g., the enhanced ID flag circuit 50-B) is powering up. A regulated supply voltage that can be measured at a voltage node 66, VREF, powers the CMOS inverter 64. The voltage at the voltage node 66 is lower than VDD. An inverter 70, powered by VDD, switches the gate of the NMOS switch 68. When VDD is sufficiently higher than VREF (e.g., the threshold voltage is reached and the second switch 28 is closed, see FIG. 3C), the first capacitor 16 is being charged to VREF. In this exemplary embodiment, the stored voltage on the first capacitor 16 is more constant than where the first capacitor 16 is charged to VDD, because it is not dependent on the variations in the forward voltage drop of a diode (e.g., the NMOS diode 26 in FIG. 3C). The stored voltage on the first capacitor 16 may also be more constant if VREF has less variation than VDD. Consequently, when the voltage stored on the first capacitor 16 is more constant there is less variation in the persistence time of the status of the ID flag. In one exemplary embodiment of the present invention, there may be two supply voltages; VDD_reg that is internally regulated, and VDD_rect that comes straight off of a rectifier (e.g., a circuit that converts the RF into voltage). If the rectifier output voltage, VDD_rect is used for VDD, that voltage could vary from about one volt to two volts, whereas VDD_reg that can be used for VREF may vary from about seven tenths of a volt to one volt. FIG. 8 includes time/voltage diagrams showing the VDD_rect signal 82 and an active low POR signal 84. The POR signal 84 starts out low when VDD_rect signal 82 is below a threshold, and holds the RFID tag 100 (see FIG. 1) in reset condition until the rectified voltage, VDD_rect signal 82, reaches the threshold. When VDD_rect signal 82 reaches the threshold, the POR signal 84 goes high. Referring to FIG. 6, the POR signal 84 is applied to the TRACK voltage node 38 such that the switch 34 closes when the power is available. It should also be noted that embodiments of the present invention may be implemented and not only as a physical circuit or module (e.g., on a semiconductor chip) but, also within a machine-readable media. For example, the circuits and designs described above may be stored upon, or embedded within, a machine-readable media associated with a design tool used for designing semiconductor devices. Examples include a netlist formatted in the VHSIC Hardware Description Language (VHDL), the Verilog language, or the SPICE language. Some netlist examples include a behavioral level netlist, a register transfer level, (RTL) netlist, a gate level netlist, and a transistor level netlist. Machine-readable media include media having layout information, such as a GDS-II file. Furthermore, netlist files and other machine-readable media for semiconductor chip design may be used in a simulation environment to perform any one or more methods described above. Thus it is also to be understood that embodiments of the present invention may be used, or to support, a software program executing on some processing core (e.g., a CPU of a computer system), or otherwise implemented or realized within a machine-readable medium. A machine-readable medium may include any mechanism for storing and transmitting information in a form readable by a machine (e.g., a computer). For example, a machine readable-readable medium may comprise a read-only memory (ROM), a random access memory (RAM), magnetic disc storage media, optical storage media, flash memory devices, electrical, optical, acoustic, or other form of propagated signal (e.g., a carrier wave, infrared signal, radio-frequency signal, a digital signal, etc.). Thus, method and apparatus for controlled persistent ID flag for RFID applications have been described. Although the present has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope and spirit of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. | <SOH> BACKGROUND OF THE INVENTION <EOH>Radio Frequency Identification (RFID) tags are used in a multiplicity of ways. They may be used in locating and identifying accompanying objects, as well as for transmitting information about the state of an object. It has been known since the early 60's that electronic components of transponders could be powered by a sequence of periodic signal bursts sent by a reader (or interrogator) and received by a tag antenna on each of the transponders. The RF electromagnetic field induces an alternating current in the transponder antenna that can be rectified by a RF diode of the transponder. The rectified current can be used for a power supply for the electronic components of the transponder, and enables the transponder to broadcast a return signal without itself having a self-contained power supply. An illustrative cycle of a prior art operation of an array of ten RFID tags may be described as follows: 1. The base station or the reader is on channel one and RFID tags 1-8 respond by beginning their participation in the identification protocol. All eight tags are successfully identified. 2. The reader now hops to channel 2, and the frequency of channel 2 allows tags 7-9 to be powered. Tag 9 will now respond by beginning participation in the identification protocol, while tags 1-6 lose their power and therefore stop participating. Since tags 7 and 8 were already identified and continue to be powered sufficiently when operating on channel, they do not participate in the protocol. 3. The reader hops to channel 3. The frequency of channel 3 allows tags 2-10 to be powered. Tags 7-9 stay powered and do not participate in the protocol. However, tags 2-6 must be reidentified in order to identify the one truly new tag 10. The RFID tags that are not well powered lose track of state information. This state information is essentially a bookmark in the communication sequence between the RFID tag and the base station. In running an ID protocol, for example, tags that newly enter the field, as well as tags that have lost power and then regained it while remaining in the field, are treated equally (i.e. tags that have lost power and regained it may be identified a second time). This process of again identifying an RFID tag that has previously been identified is, of course, inefficient. U.S. Pat. No. 6,404,325 (Heinrich et. al.) is directed at maintaining the integrity of state information retained by a Radio Frequency Transponder during a loss of power. In Heinrich, the state information is maintained by a mirror latches mechanism and a capacitor utilized as a power source for the mirror latches mechanism during the interval when the power supply to the RFID tag is interrupted. The time interval during which the mirror latches mechanism retains the state information (persistence of state) depends on the size of the capacitor. Persistence of state is also determined by the leakage current from the capacitor. Of course, leakage may be primarily due to switches connected to the capacitor and not through the capacitor itself. The switches are open, and so only semiconductor leakage current flows through them. Because the leakage current may vary with temperature, an RFID tag with a certain size capacitor may not retain state information as long as necessary at high temperatures and retain state information longer than is practicable at low temperatures. | <SOH> SUMMARY OF THE INVENTION <EOH>According to one aspect, there is provided a Radio-Frequency Identification (RFID) transponder including an identification flag circuit to maintain a state of the identification flag indicating that the RFID transponder has responded to an interrogation signal, the identification flag circuit including a first capacitor and a digital element coupled to the first capacitor to receive a voltage of the first capacitor; and a discharge circuit to drain the first capacitor via a discharge current that is distinct from a semiconductor leakage current. According to another aspect, the RFID transponder includes an additional charge circuit, wherein the semiconductor leakage current is through an open switch of the charge circuit. According to yet another aspect, the digital element is a comparator, the comparator being to output a signal indicative of the identification flag. According to a further another aspect, the discharge circuit is to maintain the discharge current substantially constant with temperature. Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows. | 20040708 | 20070508 | 20051027 | 78772.0 | 2 | LIEU, JULIE BICHNGOC | METHOD AND APPARATUS FOR CONTROLLED PERSISTENT ID FLAG FOR RFID APPLICATIONS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,887,670 | ACCEPTED | Database system and method for data acquisition and perusal | A data acquisition and perusal system and method including a database selection module, a database index generator module and a search module. The database selection module enables selection of a plurality of files for inclusion into at least one selectable database. The database index generator module enables generation of a searchable index of the data contained in the selectable database. The search module enables a search to be performed of the searchable index according to search criteria. The data acquisition and perusal system and method may also allow users to view, acquire, and generate single- or multiple-data sources locally or remotely, and allow users to compile, index, modify, and append the data sources according to default or user defined criteria. The data acquisition and perusal system and method may also selectively acquire and display data contained within remote databases depending upon the user's access permissions to such databases. Such a system allows for the capture of HTML data which is automatically indexed without human intervention and has the ability to automatically and accurately locate or “pinpoint,” and highlight specific text or groups of text designated by the user within the resulting database. Such a system contains a link module that enables custom links to be defined between selected terms of selected files of the selectable database including the custom links so that the searchable index includes only valid links. | 1. A data acquisition and perusal system, comprising: a database selection module that enables selection of a plurality of files including HTML files for inclusion into at least one selectable database; a link module that enables custom links to be defined between selected terms of selected files of the at least one database; a database index generator module that enables generation of a searchable index of the data contained in the at least one selectable databases including the custom links, the generator module enabling only valid custom links to be added to the searchable index; wherein the searchable index stores the word locations of words in the database including word locations of words in the HTML files that can be used to identify and highlight words in HTML files when those files are displayed in HTML format: and a search module that enables a search of the searchable index to be performed according to a search criterion. 2. The data acquisition and perusal system of claim 1 wherein the plurality of files includes a plurality of different file types. 3. (cancelled). 4. The data acquisition and perusal system of claim 2, further comprising: a plurality of selectable databases, each capable of including at least one file of a particular type. 5. The data acquisition and perusal system of claim 1 wherein the link module enables association of any link term with any of the plurality of files in the at least one selectable database. 6. (canceled). 7. The data acquisition and perusal system of claim 1, further comprising: each of the plurality of files including at least one field; and the link module enabling field links to be defined between the plurality of files. 8-9. (cancelled). 10. The data acquisition and perusal system of claim 1 wherein the database selection module enables selection of the plurality of files both locally and remotely via a network. 11. The data acquisition and perusal system of claim 1 wherein the search module enables sorting of any files of the at least one selectable database that meet the search criterion. 12. The data acquisition and perusal system of claim 11, further comprising: each of the plurality of files including a plurality of fields; and the search module sorting the any files that meet the search criterion according to the plurality of fields. 13. The data acquisition and perusal system of claim 1, further comprising: at least one input device; and a display utility including a graphic user interface that enables graphic interaction with the database selection, the link and the search modules via the at least one input device. 14. The data acquisition and perusal system of claim 13 wherein the display utility displays at least portions of files in the selectable database that meet the search criterion. 15. The data acquisition and perusal system of claim 14 wherein the display utility indicates terms in the displayed file portions that meet the search criterion. 16. The data acquisition and perusal system of claim 14, further comprising: the link module enabling association of at least one selected link term with any of the plurality of files in the at least one selectable database; and the display utility indicating any of the at least one selected link term in the displayed portions of files in the selectable database that meet the search criterion. 17. The data acquisition and perusal system of claim 16 wherein the display utility enables interaction with any indicated selected link terms via the at least one input device to enable perusal of linked files in the at least one selectable database. 18. (cancelled). 19. The system of claim 1 wherein the search module further comprises leading conflation logic that operates according to negative searching principles. 20-51. (cancelled). 52. A data acquisition and perusal method for finding, storing and retrieving useful information, comprising the steps of: locating a plurality of accessible HTML files according to a selected search criteria; selecting a plurality of the located files containing relevant information for automatic inclusion into at least one selectable database; defining custom linking relationships between selected terms and designated files of the selected database; verifying the validity of the custom linking relationships; generating a searchable index of the data contained in the selected database including the custom linking relationships so that the searchable index includes only valid custom linking relationships; searching the searchable index according to a selected search criterion to locate words and phrases in the data; and accurately highlighting the located terms and phrases while displaying at least portions of the HTML files in accordance with formatting control tags of the HTML files. 53-55. (cancelled). 56. The data acquisition and perusal method of claim 52 wherein said link definition step is operable to associate any link term with any of the plurality of files in the at least one selectable database. 57. (cancelled). 58. The data acquisition and perusal method of claim 52, further comprising the steps of: locating a plurality of accessible files including at least one field; and enabling field links to be defined between the plurality of files. 59-60. (cancelled). 61. The data acquisition and perusal method of claim 52 wherein said file selection step includes selecting the plurality of files locally and remotely via a network. 62. The data acquisition and perusal method of claim 52 wherein said searching step includes sorting of any files of the selectable database that meet the search criterion. 63. The data acquisition and perusal method of claim 62, further comprising the step of: file selection including selecting a plurality of files including a plurality of fields; and said searching step sorting any files that meet the search criterion according to the plurality of fields. 64. The data acquisition and perusal method of claim 52, further comprising the step of: displaying a graphic user interface that enables graphic interaction with the database selection, the link and the search means via the at least one input device. 65-66. (cancelled). 67. The data acquisition and perusal method of claim 52, further comprising the step of: indicating any of the selected linking relationship terms in the displayed portions of files in the selectable database. 68. The data acquisition and perusal method of claim 67 wherein the step of displaying includes enabling interaction with any indicated selected linking relationship terms via at least one input device to enable perusal of linked files in the at least one selectable database. 69-71. (cancelled). 72. The data acquisition and perusal method of claim 52 including the steps of: viewing and acquiring single and multiple data sources locally or remotely, and compiling, indexing, modifying, appending, and linking the data sources locally and remotely according to default and user defined criteria. 73. The data acquisition and perusal method of claim 52 including the step of: selectively acquiring and displaying data contained within remote databases depending upon the user's access permissions to such databases. 74. A data acquisition and perusal method, comprising the steps of: selecting a plurality of files, including HTML type format, for inclusion into at least one selectable database; generating a searchable index of the plurality of selected files included in the selectable database; wherein the searchable index stores the word locations of words in the database, including word locations of words in the HTML files that can be used to identify and highlight words in HTML files when those files are displayed in HTML format; and searching the searchable index according to search criteria; said data selection, database index generator and search steps allowing users to view and acquire single or multiple data sources locally and remotely, and allowing users to compile, index, modify, and append the data sources locally and remotely according to default or user defined criteria. 75. The data acquisition and perusal method of claim 74, comprising the step of: acquiring and displaying data contained within remote databases depending upon the user's access permissions to such databases. 76. (cancelled). 77. The data acquisition and perusal method of claim 74, comprising the step of: creating custom links to be defined between selected terms of selected files of the selectable database including the custom links so that the searchable index includes only valid links. 78. A data indexing and perusal system comprising: an index module that enables generation of a searchable index of a plurality of selected source files, including HTML files; wherein the searchable index stores word locations of words in the source files, including the word locations of words in HTML files that can be used to identify and highlight words in HTML files while those files are displayed in HTML format; a search module that enables a search to be performed of the index according to a search criterion to locate words and phrases in the plurality of selected source files; a display utility that displays at least portions of files in the plurality of selected source files that meet the search criterion; and an annotation module that enables users to generate annotations of the plurality of selected source files, the annotations being displayable by the display utility. 79. The data indexing and perusal system of claim 78, wherein the searchable index comprises a plurality of complementary index files. 80. The data indexing and perusal system of claim 78, wherein the annotation module is operable to store any generated annotations within the searchable index. 81. The data indexing and perusal system of claim 78, wherein the annotation module enables designation of a link term and designation of one of the plurality of selected source files to be linked to the designated link term. 82. The data indexing and perusal system of claim 81, wherein the index module is operable to store any designated link term within the searchable index. 83. The data indexing and perusal system of claim 82, wherein the index module is operable to store links designated through the annotation module only if the links are valid. 84. The data indexing and perusal system of claim 81, wherein the annotation module is operable to automatically generate links between all instances of a designated link term within the plurality of selected source files and the designated file. 85. The data indexing and perusal system of claim 84, wherein the annotation module enables automatic generation of links only if the links are valid. 86. The data indexing and perusal system of claim 78, the system further comprising a browser for displaying the HTML files that meet the search criterion and that utilizes the word locations stored in the searchable index to visually distinguish the searched words and phrases from any surrounding text in the displayed HTML files. 87. The data indexing and perusal system of claim 78, wherein the search module is operable to search a plurality of searchable indexes in a single search. 88. A data indexing and perusal system comprising: an index module that enables generation of an index of a plurality of selected source files; a custom link module that enables a user to create links between two of the plurality of selected source files; and a search module that enables a search to be performed according to a search criterion to locate words and phrases in the plurality of selected source files. 89. The data indexing and perusal system of claim 88, wherein the searchable index comprises a plurality of complementary index files. 90. The data indexing and perusal system of claim 88, wherein the index module is operable to store any custom links within the index. 91. The data indexing and perusal system of claim 88, wherein the link module enables creation of valid custom links only. 92. The data indexing and perusal system of claim 88, wherein the link module enables designation of a link term and designation of one of the plurality of selected source files to be linked to the designated link term; the link module being operable to automatically link multiple instances of the designated link term in the plurality of selected source files with the designated file. 93. The data indexing and perusal system of claim 88, wherein the selected source files include HTML files, the system further comprising a browser for displaying the HTML files that meet the search criterion and which utilizes word locations retrieved from an index of word locations to visually distinguish the searched words and phrases from any surrounding text in the displayed HTML files. 94. A data indexing and perusal system comprising: an index module that enables generation of a searchable index of a plurality of HTML files; a search module that enables a search to be performed of the index according to a search criterion to locate words and phrases in the plurality of HTML files; and a browser for displaying the HTML files that meet the search criterion and which utilizes word locations retrieved from an index of word locations to visually distinguish the searched words and phrases from any surrounding text in the displayed HTML files. 95. A data indexing and perusal system comprising: a display module operable to display a web page comprising a plurality of links to displayable web elements from the group consisting of web pages, text, images, and graphics, wherein the web page and web elements have original source internet addresses; a selection module that enables saving of the web page and selective saving of the linked elements to a local computer data storage device, thereby providing the selectively saved linked elements with local addresses; the selection module being configured to automatically modify the web page's links to the selectively saved linked elements so that they point to the selectively saved linked elements' local addresses; an index module that enables generation of a searchable index of the saved web page and the selectively saved linked elements; and a search module that enables a search to be performed of the index according to a search criterion. 96. The data indexing and perusal system of claim 95, wherein the selection module is operable to save the original source internet addresses of the selectively saved linked elements when modifying the saved web page's links to point to the selectively saved linked elements' local addresses. 97. A method of annotating, indexing, searching, and displaying a plurality of selected source files, the method comprising: enabling users to generate custom annotations of the plurality of selected source files; generating a searchable index of the plurality of selected source files; incorporating any user-generated custom annotations into the index; searching the searchable index according to a search criterion to locate words and phrases in the plurality of selected source files; and displaying at least portions of files in the plurality of selected source files that meet the search criterion. 98. The method of claim 97, wherein the step of generating a searchable index creates a searchable index comprising a plurality of complementary index files. 99. The method of claim 97, wherein the enablement step also enables a user to designate a link term and designate one of the plurality of selected source files to be linked to the designated link term. 100. The method of claim 99, further comprising the step of verifying the validity of any designated links, wherein the incorporating step incorporates links only if the links are valid. 101. The method of claim 99, further comprising the step of automatically generating links between all instances of a designated link term within the plurality of selected source files and the designated file. 102. The method of claim 101, wherein the automatic link generation step generates only valid links. 103. The method of claim 101, wherein the index generating step generates an index operable to be searched according to negative searching principles using conflation logic. 104. A method of linking, indexing, and searching a plurality of selected source files, the method comprising: enabling users to create custom links between two or more of the plurality of selected source files; generating a searchable index of the plurality of selected source files; incorporating any user-created custom links into the index; and searching the searchable index according to a search criterion to locate words and phrases in the plurality of selected source files. 105. The method of claim 104, wherein the step of generating a searchable index creates a searchable index comprising a plurality of complementary index files. 106. The method of claim 104, further comprising the step of verifying the validity of any custom links, wherein the incorporating step incorporates custom links only if the custom links are valid. 107. The method of claim 104, wherein the enablement step enables designation of a link term and designation of one of the plurality of selected source files to be linked to the designated link term; the link module further comprising the step of automatically generating links between all instances of the link term within the plurality of selected source files and the designated file. 108. The method of claim 104, further comprising the step of displaying at least portions of selected source files that meet the search criterion. 109. The method of claim 108, wherein the selected source files include HTML files, the displaying step displaying the HTML files that meet the search criterion in a manner that visually distinguishes the searched words and phrases from any surrounding text in the displayed HTML files. 110. A method of storing, indexing, and searching information from the internet, the method comprising: displaying a web page comprising a plurality of links to displayable web elements from the group consisting of web pages, text, images, and graphics, wherein the web page and web elements have original source internet addresses; selecting at least one of the linked elements for indexing; saving the web page and the selected linked elements as separate and distinct files to a local computer data storage device, thereby providing the web page and selected linked elements with local addresses; automatically modifying the web page's links to the selected linked elements so that they point to the selected linked elements' local addresses; generating a searchable index of the web page and selected link elements; and searching the index according to a search criterion. 111. The method of claim 110, further comprising: automatically saving the original source internet addresses of the selected linked elements. 112. An internet browser application that acts as a client to a remote web server and displays HTML files having formatting control tags in a graphical user interface in accordance with the formatting control tags of the HTML files, the internet browser application comprising: a database selection module that enables a plurality of HTML files to be downloaded and saved into at least one selectable database; a database index generation module that enables generation of a common searchable index of all files downloaded and saved into a selected database; and a search module that enables a search to be performed of an index generated by the database index generation module according to a search criterion to locate words and phrases in the files of the selected database. 113. The internet browser application of claim 112, wherein the database index generation module enables generation of a common searchable index that is separate from the downloaded and saved files. 114. The internet browser application of claim 112, wherein the graphical user interface displays at least portions of the HTML files that meet the search criterion in accordance with the formatting control tags of the HTML files. 115. The internet browser application of claim 114, further comprising an index of word locations of words in the HTML files, the internet browser application retrieving word locations of words in the HTML files that meet the search criterion in order to highlight the words in the HTML files that meet the search criterion. 116. The internet browser application of claim 114, wherein the graphical user interface enables users to annotate a downloaded html file. 117. The internet browser application of claim 112, wherein the database index generation module is actuated by saving a file and exiting a browser mode. 118. In an internet browser application that acts as a client to a remote web server and displays HTML files having formatting control tags in a graphical user interface in accordance with the formatting control tags of the HTML files, the improvement comprising: an index generation module that enables generation of an index of an HTML file displayed in the browser, the index being separate from the downloaded and saved files. 119. The internet browser application of claim 118, further comprising a search module that enables a search to be performed of an index generated by the index generation module according to a search criterion to locate words and phrases in the HTML file. 120. In an internet browser application that acts as a client to a remote web server and displays HTML files having formatting control tags in a graphical user interface in accordance with the formatting control tags of the HTML files, the improvement comprising: a database selection module that enables a plurality of HTML files to be downloaded and saved into at least one selectable database; and a search module that enables a search to be performed to locate words and phrases in a plurality of HTML files downloaded and saved in a selectable database; wherein the graphical user interface displays at least portions of the HTML files that meet the search criterion in accordance with the formatting control tags of the HTML files. 121. In an internet browser application that acts as a client to a remote web server and displays HTML files having formatting control tags in a graphical user interface in accordance with the formatting control tags of the HTML files, and which includes a search module enabling a search to be performed to locate words and phrases in a displayed HTML file according to a search criterion, the improvement comprising: an index of word locations of words in the displayed HTML file; wherein the internet browser application uses retrieved word locations of words in the HTML files that meet the search criterion in order to highlight the words in the HTML files that meet the search criterion while displaying the HTML file in accordance with the formatting control tags of the HTML files. 122. A method of identifying a search term in an HTML file comprising: accessing an index that identifies a word location, relative to the beginning of the HTML file, of the search term within the HTML file; displaying the HTML file in an HTML viewer; and highlighting characters in the HTML file at the identified word location. 123. The method of claim 122, wherein the word location comprises a character position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 124. The method of claim 123, wherein the character position of a word in the HTML file is determined by a combination of any preceding visible characters in the file and any preceding control tags that cause an HTML viewer to advance a file position pointer. 125. The method of claim 122, wherein the word location comprises a slot position, relative to the beginning of the HTML file, of an instance of the word in the HTML file. 126. The method of claim 122, wherein the word location comprises both a character position and a slot position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 127. A method of generating an index of word locations of an HTML file having visible characters and control tags, wherein said word locations can be used to pinpoint and highlight a word in a HTML browser displaying the HTML file, the method comprising: identifying the lengths of contiguous blocks of visible characters in the HTML file that are not interrupted by control tags; for each control tag encountered in the HTML file, determining whether the control tag is an incrementing control tag, wherein an incrementing control tag causes an HTML viewer to advance a file position pointer when the control tag is encountered; and for a word in the HTML file, generating a number identifying the location of the word in the HTML file by adding an amount by which any incrementing control tags preceding the word advance the file position pointer to the lengths of contiguous blocks of visible characters preceding the word. 128. A computer software apparatus comprising: a user interface that enables a user to enter a Boolean search expression for searching an HTML file, the Boolean search expression comprising a first text string expression, a second text string expression, and a Boolean operator on the first and second text string expressions; a search module operable to execute the Boolean search expression on the HTML file; and an HTML viewer adapted to highlight words in the HTML file corresponding to the Boolean search expression while displaying the HTML file in HTML format. 129. A computer software apparatus comprising: a user interface that enables a user to enter a proximity search expression for searching an HTML file; a search module operable to execute the proximity search expression on the HTML file; and an HTML viewer adapted to highlight words in the HTML file corresponding to the proximity search expression while displaying the HTML file in HTML format. 130. A computer software apparatus comprising: a user interface that enables a user to enter a conflation search expression for searching an HTML file; a search module operable to execute the conflation search expression on the HTML file; and an HTML viewer adapted to highlight words in the HTML file corresponding to the conflation search expression while displaying the HTML file in HTML format. 131. A method of displaying words in an HTML file satisfying a Boolean search query performed on the HTML file, wherein the Boolean search expression comprises a first text string expression, a second text string expression, and a Boolean operator on the first and second text string expressions, the method comprising: for each word satisfying the Boolean search query, accessing an index that identifies the word location, relative to the beginning of the HTML file, of that word; displaying the HTML file in an HTML viewer; and highlighting characters in the HTML file at the identified word location. 132. The method of claim 131, wherein the word location comprises a character position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 133. The method of claim 132, wherein the character position of a word in the HTML file is determined by a combination of any preceding visible characters in the file and any preceding control tags that cause an HTML viewer to advance a file position pointer. 134. The method of claim 131, wherein the word location comprises a slot position, relative to the beginning of the HTML file, of an instance of the word in the HTML file. 135. The method of claim 131, wherein the word location comprises both a character position and a slot position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 136. A method of displaying words in an HTML file satisfying a proximity search query performed on the HTML file, the method comprising: for each word satisfying the proximity search query, accessing an index that identifies the word location, relative to the beginning of the HTML file, of that word; displaying the HTML file in an HTML viewer; and highlighting characters in the HTML file at the identified word location. 137. The method of claim 136, wherein the word location comprises a character position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 138. The method of claim 137, wherein the character position of a word in the HTML file is determined by a combination of any preceding visible characters in the file and any preceding control tags that cause an HTML viewer to advance a file position pointer. 139. The method of claim 136, wherein the word location comprises a slot position, relative to the beginning of the HTML file, of an instance of the word in the HTML file. 140. The method of claim 136, wherein the word location comprises both a character position and a slot position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 141. A method of displaying words in an HTML file satisfying a conflation search query performed on the HTML file, the method comprising: for each word satisfying the conflation search query, accessing an index that identifies the word location, relative to the beginning of the HTML file, of that word; displaying the HTML file in an HTML viewer; and highlighting characters in the HTML file at the identified word location. 142. The method of claim 141, wherein the word location comprises a character position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 143. The method of claim 142, wherein the character position of a word in the HTML file is determined by a combination of any preceding visible characters in the file and any preceding control tags that cause an HTML viewer to advance a file position pointer. 144. The method of claim 141, wherein the word location comprises a slot position, relative to the beginning of the HTML file, of an instance of the word in the HTML file. 145. The method of claim 141, wherein the word location comprises both a character position and a slot position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 146. A computer software apparatus comprising: a user interface that enables a user to enter a search expression for searching an HTML file; a search module operable to execute the search expression on the HTML file; an index that identifies a word location, relative to the beginning of the HTML file, of any matching search term within the HTML file; and an HTML viewer adapted to use the word location to highlight any matching search term in the HTML file corresponding to the search expression while displaying the HTML file in HTML format. 147. The computer software apparatus of claim 146, wherein the word location comprises a character position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. 148. The computer software apparatus of claim 147, wherein the character position of a word in the HTML file is determined by a combination of any preceding visible characters in the file and any preceding control tags that cause an HTML viewer to advance a file position pointer. 149. The computer software apparatus of claim 146, wherein the word location comprises a slot position, relative to the beginning of the HTML file, of an instance of the word in the HTML file. 150. The computer software apparatus of claim 146, wherein the word location comprises both a character position and a slot position, relative to the beginning of the HTML file, of an instance of the search term in the HTML file. | FIELD OF THE INVENTION The present invention relates generally to a data acquisition and perusal system and method for locating, indexing, and accessing information, and more particularly to a data acquisition and perusal system and method for acquiring, creating, manipulating, indexing, and perusing data, and to a method and system for locating and retrieving known or unknown data for the same purposes. BACKGROUND OF THE INVENTION Computers were intended to provide an effective and efficient way for humans to manage, locate, peruse and manipulate data or objects. For example, a first, basic system and method is that demonstrated by modern word processor applications which have some search and text access capabilities, however, as far as in known, they are limited to the current file that is open. Employing this method, the user can request the location of a word in the text. Within an individual file, the computer will then take the user sequentially to each location of that text. Only string searches are allowed. By repeatedly running the search, the user can sequentially move from result to result. While it might be possible to open, many files simultaneously, the available resources and memory make this impractical. A second, improved system and method enabled by some computer operating systems include applications that allow users to search all available files, accessible by certain software applications, for words or simple phrases. They still require the user to open each of the files of interest in a word processor, viewer or other application referred to in the first system and method to access the data. The search time required is relatively great because the data available has to be sequentially read and compared with the query. A third system and method used by software applications provides improved search capabilities and is commonly known as a “search/retrieval engine”. Among other things, search/retrieval engines can essentially search and access many thousands of files simultaneously and very quickly by using pre-generated indexes of the data. For example, a user can query an encyclopedia converted to an indexed database, and by the use of highlighted text, quickly determine every place a word or phrase occurs in the text, and have the ability to instantly view those occurrences as desired. These products even take the user sequentially to each incident of highlighted text or “hit.” The computer can then take the user from hit to hit. Converting a database like an encyclopedia into a format useable by a search/retrieval engine is not simply a matter of converting its volumes into electronic files accessible by the user's computer. For efficient search performance, the contents of the files are logically indexed as to location, frequency, etc. The search functions of the engine actually search the index to determine if the query criteria are met, and then the locations of valid results are passed to the retrieval functions to display them. Without a well-designed index, a computer could take a long time to perform a search for a simple phrase that can otherwise be performed in a fraction of a second. Some search/retrieval engine application vendors allow users to generate indexes for their own files through an indexing utility, and others intend for indexing to be done only by electronic database publishers by use of a separate application designed for that purpose. Currently, a user desiring to employ the speed of a computer to search for and retrieve data from multiple disparate source files generally has three choices: (1) use the basic first system and method above to open each file in a word processor application and search them individually; (2) use the second system and method above, search each file using an operating system application, and then open each file in the list of results in a word processor application; and (3) obtain an indexed database of the sources along with a search/retrieval engine from an electronic publisher, or create a database usable by a search/retrieval engine. As far as is known, no application has been devised, however, to adequately deal with the internet and yield the results described in the third system and method above. The internet is a vast and burgeoning source of information concerning nearly every subject. But the internet is comprised of files available in SGML and its derivatives including HTML and XML and other hypertext type formats. A hypertext markup language such as HTML is a structured, yet ambiguous language. In this application, reference is generally made to HTML files and documents, which is the most common format. However, it is understood that this includes the SGML format and its other derivatives, including XML and future modifications, implementations, and standards for use in data files, databases and the internet. As far as is known, having a computer automatically and accurately determine the exact location of text within an HTML type formatted document, object, or file is not accomplished in the prior art. Consequently, there is no known practical method or system whereby a user can efficiently and effectively use a computer's speed to search for and retrieve data from a set of files accessible by the computer and get pinpoint, highlighted display of the designated text. It should be noted that the information desired may be in files, objects, or files that are unknown, and available to the user. In addition to the internet, many enterprises have extensive repositories of information stored in electronic form that may contain information an authorized user may desire and want to locate and access. Even at the lowest level, an individual computer generally contains unknown or forgotten data that the user would find valuable. All of these repositories of information cannot be as efficiently accessed by the current art as is desired. Using the current art in the third system and method above, users can add electronic bookmarks to enable them to quickly return to any part of any volume of an encyclopedia, referred to in the example above, and they can copy portions for insertion into other documents of their own creation. By use of hypertext links appearing within the database, a user is able to instantly view related data for which he had not searched. The links are generated according to a rationale applied when the database index was prepared. Adding hypertext links usable within a database is generally a more complex process. The links are intended to appear to the user in a color or format distinguishable from other data, and when activated, the computer is directed to display another highlighted portion of the database. By naming the instructions to the computer within links as “pointers” and what they link to as “targets”, the process will be facilitated. A database can theoretically have an unlimited number of identical pointers (even though what the user sees can be different for some or all of them), but any pointer can generally only have one target (a specific area of the database to display), and targets are invisible to the user. Links must be sensitive to the context of the document and context sensitivity requires intelligence. Thus, adding links to a database requires human intervention because current computers inherently lack any intelligence. Although simple linking based upon discernible patterns within text and is targeted toward files matching those patterns can easily be done programmatically, human intervention is still required to design and initiate the process. Further, such favorable linking circumstances rarely exist within typical, disparate data and even greater human intervention is required. Consequently, search/retrieval engine vendors essentially leave linking up to the creator of the search engine software or electronic publisher to do manually, and the links are generally not customizable by the user. Thus, the vendors commonly provide technical specifications on how to craft pointer and target codes for the software and how to write programs to link their unique databases. However, some word processing and other applications permit users to craft links among compatible files using manual processes. If a user desires to have the searchable data include context-sensitive links, the choices are generally reduced to: (1) obtaining a pre-linked database from an electronic publisher; or (2) creating a custom database and manually inserting links individually or by use of a custom program written for the unique situation. Beyond the problems of availability and lack of customization, a fundamental problem with the first choice is that a publisher may not consider the same links to be important as a user does. Thus, the publisher may include links that are not important to the user and may not include links that would have been important. A fundamental problem with the second choice is that manually inserting links requires a substantial amount of time and trouble that quickly outweighs any potential benefit to manually inserting links as the quantity of data increases. As far as is known, the current art does not include a system to create links by designating “pointers” and “targets” and having the program automatically create links that are all valid. It would be highly beneficial to have the results from computer searches of various sources of information that locate information from the various sources, to be quickly and easily saved locally for accessing at a later time, without having to redo the search and re-access the sources of information. This saves search time and repeating the search, which may not locate the previous information. The locally saved information can also be quickly accessed without having to relocate the information. An object of the invention is to allow someone to create his or her own custom, organized database that can be utilized effectively. Each time relevant information and files are located, they can be put into a database, indexed and made available for use. The limitations of prior systems are overcome by the present invention, which is an improved method and system for acquiring, creating, manipulating, indexing, and perusing data, and for locating and retrieving known or unknown data for the same purposes. In a preferred embodiment, the system is a stand-alone application residing on a user's personal computer that enables the user to create fully searchable databases or local sources of any size from any electronic documents accessible by the computer and selected by the user. It also enables the user to accurately and methodically locate undiscovered documents that may be of interest. By use of a word processing means integrated into the application, it enables the user to create and include new documents into the database or to create retrievable documents within the application. Any databases or documents that the user creates can be password protected to restrict access by unauthorized users who may have access to the computer. The invention provides a user with the ability to train a search engine to automatically and methodically search the internet or other data sources according to derived or evolved limitation criteria. Each set of such criteria is stored for reuse or modification as the user desires. Without limiting the criteria, the system could be directed to retrieve and completely index every file that existed on its available data sources. While that would guarantee that all data in those files would be searched for data that the user wants, there are practical limitations. If the data source is vast, like the internet, the system would attempt to index all of its files, objects, or documents, but it would quickly encounter storage limitations on the user's computer if default limitations were not automatically imposed. By artfully estimating the time and storage requirements and matching them to available resources, the system guides the user to impose limitations to produce the desired results. This method allows users to completely index all of some data sources, to filter and sort smaller percentages of greater data sources, or to survey large data sources such as the internet. In the latter case, the user can refine the resultant survey to identify smaller, but more relevant, parts of the data sources. After sufficiently iterating the refinement process, the user will be able to index and search all selected and relevant data. Thus, this system and method enable a user to predictably and efficiently solve the problem of selecting and comprehensively searching relevant data from sources with unknown content by combining human intelligence with the indexing and search/retrieval capabilities of a computer. Since the system can be trained to repeat all or parts of previous actions, the user's instructions can be perfectly carried out while repeatedly using different search criteria. Uses of the system include those identified herein as well as many others. For example, a vendor could prepare a database, kept on a remote server that contains continually updated information, to be accessed by a computer running this system. Among other things, the database could contain information authorizing the user to continue to use the system and query the database. Independent of the server, the user could then employ all or part of the system's capabilities for other purposes as desired. In one embodiment, commercial electronic database publishers could use a system according to the present invention as a publishing system to create databases with more or less homogeneous content. For example, one publisher may produce a monthly searchable, linked database containing issued United States patents, another might produce a linked database containing decisions of appellate courts, and another might produce a linked database containing documents required to be filed by various regulatory agencies, etc. Using prior systems to produce such databases requires substantial programming skills to incorporate reference links within the database, but in practice, many such links are invalid because a referenced document does not exist. Using the system according to the present invention does not require such skills because it automatically creates only valid and verified links. The graphical user interface is easily modified to comport with a particular “look and feel” desired by the publisher. In another embodiment, a data provider could maintain a continually updated database of information (e.g., statistical or a glossary) on a remote server that the user accesses via a network such as the internet. Upon being started by the user, an application automatically connects to the remote database when information from the database is needed and disconnects once it is obtained. If the remote database has changed, the user will be notified and the user's database index can be regenerated to accommodate the changes. By storing user authorization codes on the remote server in a database or table for that purpose, the provider can verify that the user is still entitled to access the service provided. The application on the user's computer can automatically be rendered dysfunctional by the passage of time unless it successfully renews its operating status by connecting to the provider's authorization code database. This embodiment provides advantages to both the data provider and the network service provider: (1) the system application can essentially be provided on a subscription or rental basis without the necessity of distribution media or elaborate license or copyright protection schemes; and (2) the network service provider's effective bandwidth is greatly increased because the system only connects to the remote server on an as-needed, when-needed basis instead of requiring an active modem connection continuously. Another object of the invention is to provide a method and system for storing search results from various sources including the internet with internet format files, objects, or documents. The locally stored results can be automatically indexed for fast searching and hyper linked by the user to make subsequent finding of the previously located information quick and simple The system and method of the invention overcomes the above-noted problems of the prior art and can be used for general purpose data acquisition, creation, manipulation, indexing, and perusal while connecting to remote data sources only as needed. SUMMARY OF THE INVENTION A data acquisition and perusal system and method according to the present invention includes a database selection module, a link module, a database index generator module and a search module. The database selection module enables selection of a plurality of files, objects, or documents for inclusion into at least one selectable database. The link module enables custom links to be defined between selected terms of selected files of the selectable database. The database index generator module enables generation of a searchable index of the data contained in the selectable database including the custom links so that the searchable index includes only valid links. The search module enables a search to be performed of the searchable index according to a search criterion. The plurality of different files may include a plurality of different file types, such as internet formatted files, objects, or documents, including HTML type formats, and word processor formats, text formats, RTF formats, etc. Generally, each database includes one or more files of a particular type. The database selection module may be configured to enable selection of the plurality of files both locally and remotely via a network. For example, the data acquisition and perusal system and method may be implemented on a computer coupled to a network, where the network may further be connected to the internet. The data acquisition and perusal system and method may be configured to copy internet files to a local storage disk, or to simply maintain a link to the internet files of interest. The link module enables association of any selected link term with any of the plurality of files in the selectable database. The link module may further enable at least one alias term to be defined for any selected link term to enable a link to be established between each alias term and any of the files in the database. Each of the files may further include one or more fields. The link module further enables field links to be defined between any two or more of the plurality of files. Such field links may be defined according to patterns, where the patterns may further be defined using wildcard characters that each replace one or more digits or characters. The search module may further enable sorting of any files of the selectable database that meet the search criterion. In one embodiment, such sorting may be according to the respective fields of the files. For example, the files may be sorted by date, by name, or by any other field types or descriptions. The data acquisition and perusal system and method may further include at least one input device and a display utility including a graphic user interface (GUI). The input device and display utility enables graphic interaction with the database selection, the link, and the search modules via the input device. The display utility displays at least portions of files in the selectable database that meet the search criterion. The portion of a displayed file typically includes any text that meets the search criterion. Such text is usually graphically indicated, such as via color, style, highlighting, etc. Also, any selected link terms defined via the link module are also indicated in a similar manner. Further, the display utility enables interaction with any indicated selected link terms via the input device to enable perusal of linked files in the selectable database. For example, a user may double click on highlighted text indicating a link term in a displayed file, where the data acquisition and perusal system and method jumps to and displays the linked file. Operation is similar for alias link terms if defined. The system and method may automatically, unambiguously, and accurately place reference links among documents within a database it creates according to a schema controlled by the user. These links enable the user to instantly view a file, object, or document referenced by another file, object, or document currently being viewed and to backtrack to any point of origin in the database. The system and method does not modify or make extraneous copies of the contents of the original database files, objects, or documents. If a file, object, or document is modified or deleted, the integrity of the database is not affected with respect to the other files, objects, or documents because either the database (i.e., the index) will be regenerated, or an error message will be presented telling the user that the file, object, or document has been modified or deleted. The application also may give the user the option to create compressed, password-protected databases for secure dissemination to other users or simply to secure the files, objects, or documents and database indexes for personal use. Embodiments of a system and method, in accordance with the principles of the present invention, provide methods and systems for acquiring, creating, manipulating, indexing, and perusing data; for locating and retrieving known or unknown data for the same purposes; for automatically connecting to remote network computers on an as-needed, when-needed basis; for validating a user's rights to use the system; and for securing pertinent data from unauthorized use. BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the present system can be obtained when the following detailed description of the preferred embodiment is considered in conjunction with the following drawings, in which: FIG. 1A is a block diagram of an exemplary computer system that is used to illustrate various aspects of the present invention. FIG. 1B is a block diagram of an exemplary network system that is used to illustrate various aspects of the present invention, where a computer is coupled to other computers in a network environment which also may be coupled to the internet. FIG. 1C is a block diagram illustrating a data acquisition and perusal system and method implemented according to the present invention. FIG. 2 is a block diagram of an exemplary searchable database index that is generated by the computer system of FIG. 1A. FIG. 2A is a schematic of an exemplary word position table as contained in a DSF file of FIG. 2. FIG. 2B is a schematic of an exemplary locator string from the word position table of FIG. 2A. FIG. 3 is a flow diagram of an exemplary startup sequence of a database application program implemented according to the present invention. FIG. 4 is a flow diagram of an index generator processing sequence of the database application of FIG. 3. FIG. 4A is an expanded flow diagram of an index generator processing step for word locations in HTML files depicted by step 406 of FIG. 4. FIG. 5 is a screen display illustrating an exemplary database registration dialog of a graphic user interface (GUI) embodiment of a database application program implemented according to the present invention. FIG. 6 is a screen display illustrating an exemplary unregister confirmation dialog of the GUI database application program introduced in FIG. 5. FIG. 7 is a screen display of an exemplary index generator dialog of the GUI database application program introduced in FIG. 5. FIG. 8 is a screen display of an exemplary search/retrieval dialog of the GUI database application program introduced in FIG. 5. FIG. 9 is a screen display of an exemplary dialog displaying a document retrieved from a searchable database index using the GUI database application program introduced in FIG. 5. FIG. 10 is a screen display of an exemplary display options dialog of the GUI database application program introduced in FIG. 5. FIG. 11 is a screen display of an exemplary link generator dialog of the GUI database application program introduced in FIG. 5. FIG. 12 is a screen display of an exemplary dialog implemented as an integrated word processor of the GUI database application program introduced in FIG. 5. FIG. 13 is a screen display of an optional field links dialog of the GUI database application program introduced in FIG. 5. FIG. 14 is a screen display of an exemplary Browser Mode Window showing an HTM (HyperText Markup Language) document retrieved from the internet using the GUI database application program introduced in FIG. 5. FIG. 15 is an example screen display of the HTM document of FIG. 14 after being saved and edited in the Browser Mode window in accordance with the principles of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, FIG. 1A is a block diagram an exemplary computer system 100 that could be used to illustrate various aspects of a data acquisition and perusal system implemented according to the present invention. The computer system 100 is preferably a conventional IBM brand compatible, personal computer (PC) system or the like, and includes a motherboard and bus system 102 coupled to at least one central processing unit (CPU) 104 and a memory system 106. The motherboard and bus system 102 include any kind of bus system configuration, such as any combination of a host bus, one or more peripheral component interconnect (PCI) buses, an industry standard architecture (ISA) bus, an extended ISA (EISA) bus, micro-channel architecture (MCA) bus, an AGP bus, a universal serial bus (USB), etc., along with corresponding bus driver circuitry and bridge interfaces, etc., as known to those skilled in the art. The CPU 104 preferably incorporates any one of several microprocessors, such as the 80486, Pentium™, Pentium II™, Pentium III™, etc. microprocessors from Intel Corp., or other similar type microprocessors such as the K6 microprocessor by Advanced Micro Devices, and supporting external circuitry typically used in PCs. The external circuitry preferably includes an external or level two (L2) cache or the like (not shown). The memory system 106 may include a memory controller or the like and be implemented with one or more memory boards (not shown) plugged into compatible memory slots on the motherboard, although any memory configuration is contemplated. The invention is also applicable to other microprocessors, other architectures and other operating systems. The computer system 100 may include one or more output devices, such as speakers 109 coupled to the motherboard and bus system 102 via an appropriate sound card 108 and a monitor or display 112 coupled to the motherboard and bus system 102 via an appropriate video card 110. One or more input devices may also be provided such as a mouse 114 and a keyboard 116, each coupled to the motherboard and bus system 102 via appropriate controllers 115, 117, respectively, as known to those skilled in the art. A storage system 120 is coupled to the motherboard and bus system 102 and may include any one or more data storage devices, such as one or more disk drives including floppy and hard disk drives, one or more CD-ROMs, one or more tape drives, etc. Other input and output devices may also be included, as well as other types of input devices including a microphone, joystick, pointing device, voice recognition, etc. The input and output devices enable a user to interact with the computer system 100 for purposes of data acquisition and perusal, as further described below. The motherboard and bus system 102 may be implemented with at least one expansion slot 122, which is configured to receive compatible adapter or controller cards configured for the particular slot and bus type. Typical devices configured as adapter cards include network interface cards (NICs), disk controllers such as an IDE or a SCSI (Small Computer System Interface) disk controller, video controllers, sound cards, etc. The computer system 100 may include one or more of several different types of buses and slots, such as PCI, ISA, EISA, MCA, AGP, USB, etc. Each slot 122 is configured to receive an expansion card 124, such as a sound card, a modem card, a network interface controller (NIC) or adapter, etc. Other components, devices and circuitry are normally included in the computer system 100 but are conventional and are not part of the present invention and are not shown. Such other components, devices and circuitry are coupled to the motherboard and bus system 102, such as, for example, an integrated system peripheral (ISP), an interrupt controller such as an advanced programmable interrupt controller (APIC) or the like, bus arbiter(s), one or more system ROMs (read only memory) comprising one or more ROM modules, a keyboard controller, a real time clock (RTC) and timers, communication ports, non-volatile static random access memory (NVSRAM), a direct memory access (DMA) system, diagnostics ports, command/status registers, battery-backed CMOS memory, etc. Although the present invention is illustrated with an IBM-compatible type PC system, it is understood that the present invention is applicable to other types of computer systems and processors as known to those skilled in the art. A data acquisition and perusal system or application program according to the present invention may be stored in the storage system 120. The database application program is retrieved into the memory system 106 and executed by the CPU 104. As described more fully below, the database application program retrieves local files, such as stored in the storage system 120, and remote files, such as accessed via a network, and generates a searchable database index. Although reference is made in the specification and claims to computer files, it is understood that the term filed encompasses documents and any other digital object that contains machine or individual readable or searchable information. The searchable index may be generated in the memory system 106 or the storage system 120 for longer term storage. The database application program further includes search and retrieval functions that enable a user to search the searchable index as more fully described below. The computer system 100 is included to illustrate that a data acquisition and perusal system and method according to the present invention may be realized on a modern computing machine with a CPU, random access memory (RAM) and external storage, such as the storage system 120. The computer system 100 enables a user-friendly graphic user interface (GUI) implementation with display and input capabilities. There are no explicit restrictions on CPU architecture or display technology. Referring now to FIG. 1B, a block diagram is shown of a network system 150 that communicatively couples a plurality of computer systems or computing devices 152, 154, 156, 158, 160, etc. together via a communication medium 162. Any one or more of the computing devices 152-160 may be implemented in the same or a similar manner as the computer system 100. The network system 150 may include any one or more network devices (not shown), such as hubs, switches, repeaters, bridges, routers, brouters, etc. The network system 150 may operate according to any network architecture, such as Ethernet™, Token Ring, Token Bus, ATM, etc., or combinations of such architectures at any available speed, such as 10 Megabits per second (Mbps), 100 Mbps, 1 Gigabits per second (1 Gbps), etc. The network 150 may form any type of Local Area Network (LAN) or Wide Area Network (WAN), and may comprise an intranet and be connected to the internet. The computer system 100 can operate a data acquisition and perusal system and method according to the present invention in a standalone mode. If coupled to a network, such as the network system 150, the computer system 100 can also access and retrieve remote files located on the networked computers 152-160. Of note, the communication medium 162 may be configured for an internet connection, an intranet connection, or other network connection. If the computer system 100 is coupled to the internet, to an intranet, or to another network via the connection medium 162, the computer system 100 can likewise access and retrieve files located through those connections. A system according to the present invention does not require that either original database source files or generated index files be located on the computer system 100. Database source files (or documents) are typically divided into fields or areas when they are created. These fields may result from word processing application that is used to create the documents. For example, WordPerfect® formatted files/documents contain both hidden and visible fields in almost every document that is created. Likewise, Microsoft® Word (hereinafter MS-Word) formatted files/documents contain certain fields. In addition, internet or HTM (or HTML, HyperText Markup Language) type format files, objects or documents contain many hidden and unhidden fields. Thus, the files/documents/objects referred to herein should be understood to contain fields. Further, a system according to the present invention includes special features for handling composite file types, such as HTML format files used over the internet. Composite files can include display codes for arrangement, graphics, fonts, hyperlinks, and other characteristics that allow “assembly” of what appears to be a single document presented on the computer monitor but which actually may be a compilation of multiple text and graphic elements stored in separate files. Unlike integral files, composite files are more efficient from a disk storage space standpoint than integral files because their reusable components, such as graphics, can be used many times by different files without having to be replicated for each file. Composite files can also include small integral programs called scripts (e.g., Java applets or Java scripts) that instruct the computer to perform other tasks while the HTML page is displayed. Regardless of the visual complexity of an HTML composite file, from a searchable database perspective, the crucial parts of the HTML composite file are those parts that contain text. FIG. 1C is a block diagram illustrating a system 170 implemented according to the present invention which performs the method of the invention. Although not limited to a single computer system, the present invention is illustrated using the computer system 100 as a standalone system as shown in FIG. 1A or as coupled to the network system 150 as shown in FIG. 1B. A file database 171 is shown in FIG. 1C which represents any file that is accessible, either locally or remotely, by the computer system 100. For example, the file database 171 may includes files located on the storage system 120 and files accessed from remote sources, such as via the internet, via the network system 150 and the expansion card 124 configured as a NIC or modem. The file database 171 includes one or more files of type A, shown as files AF1, AF2 . . . AFn, where “n” is any positive integer. The file database 171 may further include one or more files of type B, shown as files BF1, BF2 . . . BFn, one or more files of type C (not shown), etc. Examples of file types include internet or HTML format (or simply HTM), word processor format including DOC files generated by MS-Word, or similar word processing files generated by WordPerfect®, text format, RTF (Rich Text Format) files, drawing files, database files, etc. The incompatibilities and between various formats has become less since several type of formats may be included in a single file, object, or document. In this manner, the present invention contemplates any number of files or documents of any type. It is noted that any one or more of the files may be copied into local storage or may be simply accessed via an existing link to that file. For example, in a default mode, internet files are copied locally. However, the user may choose to simply access the file via a valid link or address. The system 170 shown in FIG. 1C includes a database selection module 173 that enables a user to select any number of any type of files from the file database 171 for inclusion into a selectable database 175. Of note, the term “module” represents any combination of hardware and software implemented to achieve the desired functions. For example, one or more modules described herein may be incorporated into a database application, which is stored on the storage system 120 and retrieved into the memory system 106 for execution by the CPU 104. The selectable database 175 comprises one or more databases, shown as D1, D2, D3, etc., where each database includes one or more files selected by the user from the file database 171. The selectable database 175 may include a single database with a single file or multiple files, or a plurality of databases, each including a single file or multiple files. The database selection module 173 enables the user to select and define the selectable database 175. For example the selectable database 175 may include a database D1 including files of a first type (AF1, AF2, etc.), a database D2 including files of a second type (BF1, BF2, etc.), and so on. The system 170 may further include a link module 177 that enables a user to define one or more custom links between selected files of the selected database 175. Such links are typically referred to as hypertext links. For example, the user may choose one or more link terms that should be linked to at least one file, either in the same database or a different database, in the selectable database 175. The link module 177 allows an essentially unlimited number of such link term/file pairs to be created. As further described below, when a link term is encountered in a file or document, the link term is indicated or otherwise highlighted so that the user can select the indicated link term to jump to the linked file. The link module 177 may further enable the user to define one or more aliases for each link term. For example, the user may define the terms “grape”, “tomato”, “raspberry”, etc., as aliases of a link term “vine fruit”. Each alias is treated in a similar manner as its corresponding link term. Each of the files in the selected database 175 may further include one or more fields. The link module 177 enables the user to define field links to link similar fields between two or more files. Such field links may be generated according to patterns, where such patterns may further be defined using wildcard characters that each substitute for one or more digits or characters depending upon the function of the respective wildcards, as further described below. The system 170 further includes a database index generator 179 that generates a searchable index 181 based at least on the selectable database 175. The database index generator 179 may further include the link information from the link module 177, so that the searchable index includes valid user-defined links. In this manner, the database index generator 179 is capable of processing the user-defined links in view of the selectable database 175 and incorporate only valid links into the searchable index 181. The system 170 further includes a search module 183 that enables the user to perform any number of searches of the searchable index 181 according to any desired search criterion. The search criterion may be according to any desired function or defined expression(s), such as a single term, literal phrases or terms comprising text in quotes, multiple words and Boolean operators (e.g. AND, OR, XOR, etc.), etc. The system 170 may further include a display/input utility 185 that interfaces one or more of the modules of the system 170, such as the database selection module 173, the link module 177 and the search module 183. For the computer system 100, the display/input utility 185 may be implemented using the display devices such as the video card 110 and corresponding display 112, and input devices including the mouse 114 and mouse interface 115 and the keyboard 116 and the keyboard interface 116, Further, the display/input utility 185 includes one or more software programs or drivers executed from the memory system 106 by the CPU 104 to interface the respective modules. Such programs or drivers may be separate or integrated into a single application including the modules. The display/input utility 185 preferably includes a GUI (Graphic User Interface) that enables the user to select and display one or more of the files of the file database 171, such as by pathname including directories and filenames or URL (Uniform Resource Locator) addresses, as well as one or more of the databases of the selectable database 175. The display/input utility 185 enables the user to interactively define link information via the link module 177. The display/input utility 185 enables the user to launch the database index generator 179 to generate the searchable index 181. The display/input utility 185 enables the user to define search criterion via the search module 183 and to view the results of a search. As described further below, the results may be viewed as a list of files that match the search criterion, and the user may select and view the contents any of the listed files. The display/input utility 185 displays portions of the files that match the search criterion, as well as any predefined links defined via the link module 177. The system 170 shown in FIG. 1C is exemplary only and may include other modules and functionality. For example, the system 170 may include an integrated word processor dialog, one or more link generator dialogs, a search/retrieval dialog, a display options dialog, an integrate browser dialog, etc. The system 170 provides several advantages over other types of search/retrieval applications or database programs. The system 170 enables a searchable index to be generated that includes valid, customized links. The searchable index provides a static and enables a snapshot of files or databases to be taken at a given time for perusal by a user at any time, even if the originating files change or are no longer valid. The searchable index is also dynamic in that the user may update the selected files and links and generate an updated index. The system 170 also enables pinpoint searches of multiple files at the same time, including multiple HTML files retrieved or accessed locally or via the internet. FIG. 2 is a block diagram of an exemplary searchable database index 200 generated by a data acquisition and perusal system and method according to the present invention, such as the system 170. The database index 200 corresponds to, and is a more specific embodiment of, the searchable index 181 shown in FIG. 1C. The user makes an inquiry about specific words or phrases by entering those specific words or phrases via the search module 183. The search module 183 first parses the inquiry into a list of its discrete terms, i.e., words, numbers, spaces, etc., and then accesses the database index 200 to locate the terms in various files/documents of selected databases. In operation, the search module 183 first compares each term of the search query against “words” contained in a stop word list 201 of the database index 200. The stop word list 201 is a file containing a list of “noise words”, or words that frequently occur in a file/document that do not contain distinguishable characteristics. For example, stop words are “words” such as “and”, “as”, “the”, “a”, “I”, “for”, certain punctuation, etc. Although a default stop word list is provided for each database index that is to be generated, a user may edit the stop word list 201 for a particular database index that is to be generated and include additional stop words or remove unwanted stop words from the default stop word list. If a stop word is found among the terms of a search query, the search for that term is terminated because the search module 183 considers that term to be a noise word and does not allocate further resources toward searching the files for that term. However, the length of the term is stored in the search engine's dynamic buffers for future phrase analysis. For example, if the search query contains the terms “big for tall”, the word “for” is considered a stop word and a length of the stop word, i.e., five (three letters plus two white space delimiters), is stored in place of the spaces and the word “for”. Thus, as described in greater detail herein, the search query becomes a search for files/documents that include the words “big” and “tall” with five spaces/characters between the words. If the search had been the search query “big as tall”, where the word “as” is considered a noise word, the search query becomes a search for the words “big” and “tall” with four spaces/characters there between. If a stop word is not found that corresponds to a term of a search query, the search module 183 then searches a master word index 202 for the term of the search query. The master word index 202, like the stop word list 201, is generated at the time the database index 200 is generated and is typically a binary file that includes a reference to each word, other than stop words, that appears in each of the files/documents of the database that is to be searched using the search module 183. Each word of the master word index 202 is associated with information regarding the word's length and regarding the files/documents in which the word appears. The master word index 202 is best conceived as being a file made up of three parts which are referred to herein as Part 1, Part 2, and Part 3. Conceptually, Part 1 of the master word index 202 file is a list of segments, each segment corresponding to a file/document number. For example, segment number one corresponds with file/document number one, segment number two corresponds with file/document number two, etc. Further, each segment is actually a smaller list whose beginning and end points are known by Part 2 of the master word index 202 file. Of note, Part 1 of the master word index 202 file is written only if it is needed and thus only if there is more than one file in the database. In the case of a one file database, Part 1 is not written because it is not needed to distinguish one file from another. Part 2 of the master word index 202 file, like Part 1, is a list of segments; however, each segment corresponds to each of the words in the database and is combined with information needed to find files/documents in which a given word appears in the database. Of course, if the database contains a single file, Part 2 becomes the first part of the master word index 202 file. In one embodiment, the standard segment of Part 2 is broken down thusly: (a) First, a tagged binary string. Although the tag is arbitrary, in this embodiment, the tag is an ASCII 8, ASCII NULL pair, which tells the search module 183 that a word string follows. Following this pair is a two-byte binary coded integer representing the length of the word string. Following this integer is an ASCII representation of the word string. (b) Following the tagged binary string is a sequence of twelve bytes comprised of three sets of four-byte integers or “long integers”. Each long integer provides additional information necessary to find the word string in its database file(s). These twelve bytes are broken down thusly: (i) the first four of the twelve bytes encode the word's word number as a long integer. (ii) the next eight of the twelve bytes encode two long integers whose interpretations depend upon one another. The following Table I indicates possible values of the two long integers and their interpretation: TABLE I Long Integer Interpretation If first long And second integer (x) long integer is: (y) is: Interpolation: Positive Positive. First number (x) is the and less number of files in the than the database containing the number of word. files in the Second number (y) is an database. index to the file position in Part 1 of the Master Word Index at which starts the list of file numbers containing this word. Thee list of numbers is x entries long. Positive, Positive x indictaes the number of and files that DO NOT contain the greater given word. This number is than the determined by subtracting number of the number of files in the files in the database from x. database. y is an index to the file position in Part 1 of the Master Word Index at which starts the list of the file numbers that do NOT contain this word. The length of this list is the number x, less the number of files in the database. Positive −1 x is the file number of the one and only file in the database which contains this word. (No entry is nedded in Part 1.) −1 −1 All files in the database contain this word. (No entry is needed in Part 1.) The information contained in Part 2 of the master word index 202 enables the search module 183 to expedite searching procedures for any search query that may be entered into the search module 183. Part 3 is a sequence of three indices, herein referred to as a first index, a second index, and a third index, for eliminating search terms that do not appear in Part 2 of the master word index file. Essentially, once a database index has been generated, the search module 183 uses Part 3 as a “negative search” index, i.e., an index to quickly eliminate search terms that do not appear in the database. In one embodiment, before the first of these three indices, there is a two-byte ASCII 5, ASCII NULL pair that serves as a dividing point between Parts 2 and 3. The first index of Part 3 is a numeric index which consists of 110 long integers. The first ten long integers are indices into the Part 2 information for words starting with “0”-“9”. Thus, when the database index 200 is generated, offsets for the words starting with “0”-“9” in the Part 2 data are recorded in each of the first ten long integers. If no word in Part 2 starts with the given single digit, four ASCII 255's are written into the corresponding long integer of the first ten long integers. Following these ten long integers are 100 long integers for words starting with the pairs “00”-“99”. Similar to the first ten long integers, offsets for words in the Part 2 data are recorded, but if no word starts with the given pair, four ASCII 255's are written to that long integer of the first index. The second index is an index for “odd” leading characters. This index is a list of 255 long integers, corresponding to ANSI characters 1-255. Like the first index, offsets for words in the Part 2 data are recorded, but if no word in Part 2 starts with a given character, four ASCII 255's are written to the corresponding long integer of the second index. Also, if the given character is a letter, a numeric digit, or any other character that a user is not intended to find with the search module 183, four ASCII 255's are written to the long integer that represents that character. The third index is a list of long integers that index words with alphabetical leading characters. The third index is of variable length depending on whether the index is a two or a three dimensional index (to be described herein). The first 26 long integers in the third index are offsets for words in the Part 2 data that begin with the single letters “a” through “z”. If no words in Part 2 begin with a given letter, four ASCII 255's are written to the corresponding long integer. The next 676 (26 squared) long integers of the third index are offsets for words that begin with the pairs “aa”, “ab”, “ac”, etc., is through “zz”, thus, creating a “two dimensional” index from the third index. Offsets for these words in the Part 2 data are recorded in the 676 long integers, but if no word begins with a given pair, four ASCII 255's are written to the corresponding long integer. If desired, the third index can be a “three dimensional” index, i.e., an index including references to single alpha characters (26), pairs of alpha characters (676), and three alpha characters. If the index is three dimensional, then 26 cubed (17576) long integers follow “zz”. These long integers index words beginning with the triplets “aaa”, “aab”, “aac”, etc., through “zzz”. Again, if no word begins with a given triplet, four ASCII 255's are written to the corresponding long integer for that triplet. Following these three indices is a nine byte string. The string begins with a single character that is ASCII 2 if the third index is two dimensional, and ASCII 3 if the third index is three dimensional. Following this character is a long integer corresponding to the offset at which the Part 2 data begins, i.e. the first character following the Part 1 data, if there is any Part 1 data. The last four bytes are a long integer corresponding to the first byte that follows the last byte of the Part 2 data. This is the offset for the ASCII 5 in the ASCII 5, ASCII NULL pair that tags the beginning of the three indices of Part 3. Because the size of the three indices of Part 3 can be computed exactly based on the known dimensions of the alpha locator string as coded in byte 1 of this 9 byte string, this final four-byte long integer is not strictly necessary. After the search module 183 determines which files contain the search terms, a word number index 203 is accessed to find the exact location of the search terms in each file of the database. The word number index 203 is included in the database index 200 and can be described by two files, a DSI file 204, and a DSF file 205. The terms “DSI” and “DSF” are somewhat arbitrary character strings and are commonly used as file extensions for the respective files in the word number index 203. Broadly speaking, the terms represent a file (DSF) and an index (DSI) to that file, but for purposes of understanding, each term is referred to as a file from a portion of the database index 200. It should be noted that, in a similar manner, the remaining portions of the database index 200 are also designated with similar character strings to designate files included in the respective portions of the database index 200. The word number index 203 is used by the search module 183 to find the character and slot positions of words in database files. A character position is defined as the number of the logical byte or character in a file at which a word starts. For text files this is straightforward. For RTF, DOC (MS-Word), and HTM files, a translation from the actual binary file as stored on the disk to the logical file is necessary. A slot position is defined as the numeric position of the word in the file, a “word” being defined as any contiguous unit of text, including stop words, that appears between white space. Hence, for a file whose sole contents is the string “Have a nice day!”, the word “nice” has a character position of 7 because the count starts at 0, where ‘H’ is at position 0. In addition, the word “nice” has a slot position of 3 because the count starts at 1, where “Have” is at position 1. As stated, the DSI file 204 is an index into the DSF file 205 and contains a list of indices. This list contains a sequence of long integer pairs, encoded as eight bytes, for each file in the database. For a file which contains searchable words and has an entry in the DSF file 205, the first long integer in a DSI long integer pair is a start position in the DSF file 205 of information relating to that file and the second long integer in the pair is an end position of the information in the DSF file 205. For a file which contains no searchable words such as an HTM file that is simply a frame container, or a nonsense file that is filled with stop words only, each long integer of the long integer pair has a value less than 0, indicating that no DSF entry exists for the particular file. With reference to FIG. 2A, the DSF file 205 for a database index 200 contains a sequence of word position tables 219 for each file in the database that contains searchable terms. Of note, some files of the database may be without searchable terms and, thus, not included in the DSF file 205. As stated, examples of files without searchable terms might include HTM pages that describe frame containers only, and thus have no searchable data of their own, or nonsense files which contain only stop words. The beginning and end of each word position table 219 in the DSF file 205 is coded in the companion DSI file 204. For each file which has a word position table 219, the table 219 is laid out in columns as shown by a single row view. The first column of the word position table 219 includes character positions 220. The character positions 220 comprise variable length binary strings containing a sequence of long integers indicating character positions at which a given word appears in the file for which the word position table 219 was generated. In the second column of the word position table 219, a word slots list 222 is provided which is another variable length binary string containing another sequence of long integers, each indicating a slot position at which given words in the file appear. The correspondence between the character positions 220, the word slots 222 and their associated words is recorded in a locator string 224, i.e., the third column of the file's word position table 219. In this embodiment, the locator string 224 is a variable length binary string containing a sequence of twelve-byte sub-segments, each sub-segment coding three long integers. As illustrated in FIG. 2B, each twelve-byte sub-segment of the locator string 224 begins with a word number 228. The word number 228 is followed by a character position index 230 which is an index into the first column of the word position table 219 and indicates the location of the long integer that represents the position of the first character of the word in the file. This character position index 230 is followed by a slot position index 232 which is an index into the second column of the word position table 219, the word slots list 222, and indicates the location of the long integer that represents the position of the word in the file. Referring to FIG. 2A, a number of elements in locator string 226 comprises the fourth and last column in the word position table 219. The number of elements in locator string 226 is a long integer'and stores the number of sub-segments in the locator string 224. Referring back to FIG. 2, a WDN file 216 is shown that represents a streamlined master word index 202 and contains data that is loaded into WDN maps, which are used for word searches on primary databases. These searches are typically faster than direct searches of the master word index 202 because the WDN file 216 is commonly loaded directly into the memory 106 of the computer system 100. Of course, compared to accessing the hard disk storage system 120 of the computer system 100, the memory 106 provides faster access for the search module 183. However, the memory 106 is limited in size and, thus, the size of the WDN file 216 may be limited. In this embodiment, the data in the WDN file 216 consists of segments, one segment per each word in the database, where each segment consists of 52 bytes. The first 40 bytes contain the string representation of a given search word (e.g. “apple”). This string is padded on the right with spaces, so that it is always 40 bytes long, thus allowing easier loading into the word map. The next twelve bytes precisely duplicate the data in the three long integers stored in Part 2 of the master word index 202. In other words, the first long integer of the twelve bytes encode the word's word number. The next eight bytes encode two long integers, whose interpretations depend upon one another. Refer to Table I for possible interpretations. For file/document organization, the database index 200 also includes a contents table 209 to assist the search module 183 to organize files/documents for display when a search has completed. In this embodiment, the contents table 209 includes two files, a COI file 210 and a COF file 211. The contents table 209 operates in conjunction with fields list files 212. The COI file 210 is an index into the COF file 211. The COI file 210 contains a sequence of four-byte binary encoded long integers, one long integer for each file in the database. These long integers encode a start position in the COF file 211 at which information for the given file begins. For example, to find the field information for the thirteenth file in a twenty-file database, the software of the computer system 100 retrieves the thirteenth long integer encoded in the COI file 210. The system 100 retrieves the fourteenth long integer encoded in the COI file 210 to determine where the fourteenth file's information begins and the thirteenth file's information ends in the COF file 211. Using these two values, the system 100 then extracts the characters from the COF file 211 and thus obtains all the field information for file thirteen of the database. Of course, for file twenty in this example, the system 100 simply reads the twentieth long integer in the COI file 210 to find the start position for the information in the COF file 211. Since no file follows the last file, the end position for the information is simply the end of the COF file 211. The COF file 211 contains the field information for each file in the database. Although each file in a given database has the same number of fields, though a particular file may have several blank fields, it should be noted that different databases may have different numbers of fields for the files in their databases. For example, HTM databases typically have fewer fields per file than databases containing MS-Word documents. Field information for a particular file is tab delimited. In the embodiment shown, characters are not used to delimit the field information for one file from the field information for another file. Instead, the last text character of field information for one file is immediately followed by the first character of field information for the next file. When performing a search of a database, search results for a database may be ordered based on a number of different file fields taken from the fields list files 212, including title and date fields. The fields list files 212 aid in determining a proper sort order for files based on different fields. These different files are designated CO1, CO2, . . . CO# Files 213. Each of these files 213 is a list of four-byte binary encoded long integers. The long integers correspond to the numbers of each file in the database. The file numbers are presented in the order in which those files should be presented so that the files are sorted according to the given field order. For example, in a four-file database where field 1 is a title field and the files in the database are as follows: File 1—TITLE: “Warthogs Eat Wooly Worms” File 2—TITLE: “Canaries Crave Caraway Seeds” File 3—TITLE: “Aardvarks Ate Ants” File 4—TITLE: “Dogs Dine on Dairy Dumplings”; the CO1 file contains the file numbers 3, 2, 4, 1 in that order, because the alphabetical sort order for these files by title is Aardvarks (file 3), then Canaries (file 2), then Dogs (file 4), then Warthogs (file 1). In this example, the CO2 file is based on a date field in the files so that the file numbers are in a different order based on date. Thus, the files 213 each contain a presorted list of file numbers that assist the search module 183 to organize the files found in a search based on a selected field. Referring to FIG. 2, the WDN file 216 is part of a word lists structure 214. The word lists structure 214 includes files that contain different organizations of information associated with the words from the selected databases, the files being available to expedite the search of the database index 200 for the terms of a search phrase. In this embodiment, the word lists structure 214 includes a word length (WDL) file 215 that comprises an index of words according to their length, a reverse word order (WDR) file 217 that comprises an index of words spelled in reverse order (i.e., right to left order) and that are alphabetized according to the reverse spelling of the words, and the WDN file 216. Thus, the word lists structure 214 is useful when a search query includes terms such as leading conflation searches, i.e., searches that call for all words meeting a search criteria in which only the last few letters of the search term are required to be met in the search query. For example, a search for “*ample” creates a hit for the words “sample”, “example”, “ample”, etc. In this embodiment, if the search term is not found in the WDN file 216, the search for that term is terminated because the files/documents of the selected databases do not contain the term of the search query. If the search term is found in the WDN file 216, the exact location of additional information about the term stored in the master word index 202 is provided to the search module 183. If the computer does not have enough memory 106 to store the WDN file 216 in a memory map, the master word index 202 is searched directly for all information about the word, thus bypassing the WDN file 216 of the database index 200. In one embodiment, WDN files 216 of three databases are stored in memory 106, if possible, because users frequently select three or less databases to search and, typically, three or less WDN files 216 do not overly burden the memory 106 of a computer system operating the search module 183. Of note, the search module 183 must still perform more tasks before displaying the documents that fit the search conditions, and these tasks are not necessarily related to any specific search. Any document displayed also exhibits any hypertext jump links tying it to other files in the database to which it belongs. When the database is indexed to generate the index files, a jump link list 206 is also generated. It contains an OAI file 207 comprising an index into an OAF file 208, which contains expansive data about hypertext links that exist in the database files. To assist in the understanding of the database index 200, the following narrative of a search for the word “unique” from the perspective of FIG. 2 is offered. In this example, a database index is created for each of three databases. One database includes three HTM files, a second database includes three RTF files, and a third database includes four DOC files. In each of the databases, the word “unique” appears twice in one document and once in another document. Therefore, upon a search for the word “unique”, each database has two files with at least one hit, one file with two hits and one file with one hit. The user selects the three databases and generates database indexes. The user presses “Enter” in the search dialog, requesting a search of the selected databases for the word “unique”. The search module 183 determines that there are three databases selected, and all are primary databases. Because they are primary databases, the corresponding WDN files 216 are loaded into memory 106. Starting with database 1 (the HTM database), the search module 183 searches the HTM WDN file for the word “unique”. The return value indicates that “unique” exists in this database, has a given word number (e.g., 138), and has two associated numeric values. In this case, the two values might be 4 and 68. The interpretation of the numeric values is carried out according to the interpretations described in Table I, where x=4 and y=68. Because the HTM database is a three-file database, and x is 4, then row 2 of Table I applies, i.e., x (or 4) minus the number of files (3) equals one. Thus, one file does NOT contain the word “unique”, but the other files do. The file number of the single file that does not contain the word “unique” may be found at position y=68 in the master word index 202. The search module 183 next looks in the master word index 202 at position 68 and reads one four-byte binary encoded long integer, whose value is 1. This is interpreted to mean that files 2 and 3 in this database contain the word “unique”. Thus, all the files in the first database that contain the word “unique” are known. The search module 183 next performs a search on the second RTF database with similar results, perhaps finding that “unique” was word number 122 and files 1 and 3 contain the word “unique”. This is followed by a check of the third database, i.e., the four-file MS-Word DOC database, where the word number is 190 and the numeric values are x=6 and y=156. Again, according to Table I, the return values indicate that two (6−4=2) of the four files in the database do not contain the word “unique”, and those two files are recorded at position 156 of the master word index file 202. Reading the two four-byte binary encoded long integers at position 156 in the master word index 202 indicates that files 1 and 2 do not contain the word “unique”, and thus files 3 and 4 do contain the word “unique”. Thus, at this point, the user knows that each of the three databases has two files that contain the word “unique”. These files include Files 2 and 3 of Database 1, Files 1 and 3 of Database 2 and Files 3 and 4 of Database 3. With this information in hand, the next step of the search module 183 is to display the titles and other appropriate fields of the found files in the dialog, in the sort order specified by the user. In this example, assume that the user is sorting by document title and that the document title corresponds to field number four. First, the search module 183 reorders its file number hits list to correspond to the final display selected by the user. Initially, the file number order may be represented as the following ordered pairs (database number, file number): (1,2), (1,3), (2,1), (2,3), (3,3) and (3,4). The search module 183 begins by loading the full contents of the first database's CO4 file (213, member of 212), since ordering is by field number four. A comparison of the ordered contents of the CO4 file to the two “hit” file numbers for database 1 indicates that file 3 should be displayed before file 2. This process is repeated for databases 2 and 3, resulting in a final sorted list of: (1,3), (1,2), (2,1), (2,3), (3,4), (3,3). Now that the search module 183 has sorted the complete hits list, the numeric pairs are translated to field list strings 212. The search module 183 begins by looking in the COI file 210 of Database 1's contents table 209. In this example, the COI file 210 indicates that the field information for file 3 begins at position 112. Further, because 112 is the third and final number stored in the COI file 210, and the total file length for the COF file 211 is 172, the field information for file 3 ends at position 172. Reading the data in the COF file 211 from position 112 to 172, the search module 183 gives the fields for the file, including a file name (field one) of “1 uniq.htm”, a title field (field four) of “Unique appears only once”, and a closing date field, with blank fields in between. The search module 183 sorts these fields and composes a string in which field four is presented first, followed by the database name, followed by a number of other mostly blank fields (excluding the file name), and concluding with the file date. This string is output to the display. A similar process is carried out for each file hit, allowing a total of six field strings to be output to the dialog display 112. At this point, it is up to the user to select a file to view. If the user selects the third file in the list, which would be the first file of database 2, the dialog is closed and file 1 of database 2 starts to open. During the opening process, OAI and OAF files 207 and 208 for database 2 are checked to see if any string ranges in the RTF file need to be highlighted and treated as jump links. In this case, no jump links exist in the file. Also during the opening process, the word number index 203 for database 2 is used to determine the character ranges in file 1 of database 2 that are to be highlighted and treated as search terms located in the file. The first step in using the word number index 203 occurs when the search module 183 opens the DSI and DSF files 204 and 205 for database 2. The DSI file 204 is a binary file listing pairs of long integers, each long integer coded as a four-byte binary number. Every file in a database has a corresponding pair of long integers in the DSI file 204, listed in file number order. Hence, file 1 corresponds to the first pair of long integers in the DSI file 204, and the last file in the database corresponds to the last pair of long integers in the DSI file 204. If both long integers are positive in value, then they are interpreted as beginning and ending indices into the DSF file 204, indicating the start and end of a word position table 219 describing a database file. If both long integers are less than 0, then the DSF file 205 contains no entry for this file. In the case of file 1, a DSF 205 entry exists, so the first two long integers in the DSI file 204 indicate the beginning and ending ranges for this entry in the DSF file 205. The search module 183 temporarily extracts this segment into main memory 106 and examines it. The layout of information in this segment is determined by first examining the last four bytes of this segment, and translating it into a number. The number is the number of elements in the segment's locator string 224, which immediately precedes the last four bytes of the segment. The search module 183 knows that each locator string 224 entry is twelve bytes long, and thus the locator string 224 is 1200 bytes long if the number of elements is 100. The search module 183 then examines the first entry in the locator string 224. This entry, as is true of all the entries, codes three long integers in its twelve bytes. The first four bytes code the word number 228 for the first indexed word in the file. For example, the file may begin with the word “Zebra” and end with the word “aardvark”, but since “aardvark” lexically precedes “Zebra”, “aardvark” is considered the first indexed word in the file. The second four bytes indicate the character position index 230 information for this first word, which should be 0, indicating the beginning of this DSF 205 segment. The third set of four bytes indicates the start of the slot position index 232 information for this first word, which will thus be the position in this DSF 205 segment at which the word slots list 222 information begins. Thus, the DSF 205 segment has been divided into four parts, including the character positions 220 addressed by the second byte of each locator string 224; the word slots list 222 addressed by the third byte of each locator string 224; the locator string 224, in this case containing 100 twelve-byte segments; and the number of elements in locator string 226, in this case 100. As stated earlier, if the word number for “unique” in database 2 is 122, the locator string 224 is searched for an entry whose word number portion is 122. Once this locator string 224 entry is found, the second long integer in the locator string 224 is read and interpreted, for example, a value of 68. Following this, the next locator string 224 entry is read and interpreted, for example, a value of 76. Thus, the eight bytes starting at 68 and ending at 76 in this segment indicate the starting positions for the word “unique” in file 1. Since these bytes are interpreted as four-byte long integers, this indicates that “unique” occurs twice in file 1. For example, the first long integer could indicate that “unique” begins at character position 100 and the second long integer could indicate another instance beginning at character position 200. With this information, plus the knowledge that “unique” is six characters long, the search module 183 is able to identify character positions 100 to 106 and 200 to 206 of file 1 in database 2 as the location of the two instances of the search term in this file. These text ranges are indicated through operations such as highlighting, and the file is finally displayed for the user. Of course, the search module 183 treats the character positions in the remaining files in a similar fashion for indicating or highlighting the terms for a user. FIG. 3 is a flow diagram of an exemplary startup sequence of a database application program implemented according to the present invention. When a user starts the program, a user logon sequence is initiated at a block 301. The user logs in to the system, and the program first loads the previous interface display settings or default settings if there are no previous interface display settings at next block 302. The interface display settings include a list of selected databases. The program checks each database that has been selected for searching and validates selected database files at next block 303. If the validation fails as indicated at next block 304, a message is displayed alerting the user that the database has corrupt or missing files at block 305 and deselects the problem database from the program. If there are more databases that have not been validated as determined at block 306, then operation returns to block 303 to resume the validation procedure. Each database has an initialization file that the software of the system 100 uses to generate the database index 200. Once all selected databases have been validated or deselected and success is achieved at block 304, the validated databases' initialization files are loaded at next block 307 and then operation proceeds to next block 308, where a start screen is displayed and the program waits for user instructions. When logged in to the program, a user may generate a database index. FIG. 4 is a flow diagram of an index generator processing sequence of the database application of FIG. 3. When the user starts the database application, a database generator initializes and loads previous settings at block 400. The database generator then generates a table of files to process at block 401 based on the generator settings when the user begins the index generation process. The database generator then extracts field information (or data) from the top file in the processing table at block 402 and proceeds to the next file in the processing table as indicated at block 404 until all of the files have had their field data extracted for later compilation into the contents table 209 as determined at decision block 403. The next series of steps corresponds to producing data for creating the master word index 202 and the word lists 214. For each file that is processed, valid words are extracted from the file and inserted into a word table at next block 405, an index of the word locations in the file is generated at next block 406, and a table of link patterns and field matches among the files that have been processed up to that point is then generated at next block 407 as described in conjunction with the jump link list 206. Each file in the table of files is sequentially processed in like manner as indicated by block 409 until the last file has been processed as determined at block 408. In particular, operation loops between blocks 405-409 until the last file is processed as determined at block 408. This is the HTML art? Yes. It's the art we add to process HTML files. Should it be described independently? Independent from what? FIG. 4A and the disclosure that follows about it are independent from the rest of the disclosure as I see them. Block 406's functions regarding HTML format files are more fully illustrated by FIG. 4A. The format is first determined to be an HTML file or a non-HTML file at block 417. If the file is not an HTML file, a fast and straightforward string analysis method is used to determine the locations of words within the displayable text string of the file. For example, if a file consists solely of the string “hello, world”, the first word occupies file positions 1-5, and the second word occupies file positions 8-12. Once the search engine reports that “world” is in the file, it determines its file positions so the word can be set off with different color text or by some other means. If the file position information for the word is not accurate, then the retrieved word will not be highlighted accurately. The string analysis method first requires obtaining an index string wherein all visible characters occupy positions absolutely relative to each other. The index string is then parsed into words entered into an index along with the numeric word location in the string. In the “hello, world” example, the search engine can then go to the absolute position of 8 as the beginning of “world” instead of the relative position of “the end of ‘hello’ plus 3” to get the display data for the word. A string analysis method can be adapted to handle embedded control characters provided their behavior and characteristics are consistent. For example, an image in a RTF file may consist of thousands of bytes, but the beginning and end of the sequence is consistently identified, and the entire sequence always affects the file position the same way. Thus, the string analysis method can simply discard all image byte sequences without affecting the absolute position determination of visible characters in words. HTML files involve major complications for using a string analysis method to determine file positions. HTML control tags are placed in line with visible characters. Some of the tags cause the file position to increase, and some do not. Furthermore, the parameters and tag content can be of unlimited and indeterminate length. A simple HTML file that only displays “hello, world”, can have thousands of invisible control characters before the first word, thousands between it and the second word, and thousands after that. Furthermore, whether those control characters cause the file position of a visible character to increase or not depends on the type of HTML tag and the interaction of other HTML tags. Consequently, obtaining an accurate index string to parse is immensely difficult when HTML files are involved. Other mark up language file types, such as SGML, etc., present similar but less egregious problems in obtaining accurate index strings. The method described herein for HTML files can also be used for other types of mark up language files. The problem is that there is no known accurate way to determine what the effect of present and future HTML control tags will be relative to the file positions of visible words displayed by an HTML viewer when using a string analysis method. HTML viewer technology includes a text ranging method to determine where visible characters are displayed. Essentially, this method assigns a null value to non-incrementing control tags, including their parameters, and a byte value to tags that cause the display to advance the “file position pointer” when they are encountered. The technology also includes rules for determining whether the interaction of tags changes their behavior with respect to advancing the file position pointer. An accurate index string representing not only the relative file positions of words within an HTML file but also the starting position can be generated using a text ranging method. However, the method is slow compared to a string analysis method because each byte in the file has to be analyzed individually, and single byte analysis using the text range method requires beginning at the first byte of the html string. Thus, the time required for analysis increases exponentially with increasing lengths of files to be analyzed. The present invention overcomes the inaccuracy of the string analysis method used on HTML files and the slowness of the text ranging method. The entire HTML file is a string of bytes, which will be referred to as the html string. From it, a second string consisting of only visible characters and single byte representations of all adjacent control characters combined will be derived and referred to as the visible character string. The objective is to generate an index string for parsing that will contain visible characters positioned absolutely relative to one another numerically. The index string is analogous to a plain text file string or structured file strings, such as RTF, etc., and can be unambiguously parsed to determine word locations absolutely relative to one another. At block 418, all HTML control tags and their contents are converted to single characters in the non-displayable range, typically ASCII 1 through ASCII 31. In the same block 418, adjacent strings of these control characters are then combined into just one control character. Thus, the example of “hello, world”, would be reduced at most to 15 characters regardless of the length and complexity of embedded HTML tags. This is the visible character string. The HTML viewer starting position of the first visible character must next be determined relative to the html string, which is done at block 419 by using the text ranging method. From that point, the objective is to maintain synchronization between the html string and the visible character string. String analysis is used for adjacent visible characters, and the method involves designating a sub-string with its start being the character following a control character and the end of the sub-string being the character preceding a subsequent control character. Such a sub-string segment is then added to the building index string in one step, whether it is one or thousands of characters in length as depicted by block 420. At this point, the effect of the encountered control character must be determined, and that first involves synchronizing the entry point for the text range method into the html string. Depicted by block 421, the length of the sub-string added to the index string in block 420 is added to an html string processing variable, and that is where the text range method is applied to the html string. One by one, each byte is analyzed as depicted by block 422. If it advances the file position pointer, it is added to the index string. If the next character is not visible (block 423), a test for the end of the html string is performed at block 424. If so, the index string is completed, and processing is transferred to block 427 for string parsing and subsequent word location index generation, block 428. If the next character is visible, resynchronization of the HTML string processing variable is performed at block 425 so that the next entry point will land on the next control character after the length of the next sub-string is added when block 421 is next encountered. Before leaving block 425, the next byte is analyzed at block 426 to determine if the end of the string has been encountered. If so, processing is transferred to block 427 as previously described. If not, the processing is transferred to block 420 again, and the process continues until the entire index string is accreted. The process of block 407 on FIG. 4 is straightforward. Link patterns and field matches are designated by the user through the Linking Control Panel depicted by FIG. 11 and the Options for Field Links dialog depicted by FIG. 13. When a user designates a custom link word by entering it in text box 1101, associates it with a specific file (such as a glossary) by entering its path into text box 1102, and then clicks the Add New Link button 1104, instructions for that link have been programmed into the index generator. Likewise, when a user specifies a link pattern by entering it (with or without optional wildcard characters) in text box 1106, associates it with a particular field number by selecting one in the options box 1107, and then clicks the Add New Link button 1108, instructions for that link pattern have been programmed into the index generator. The user selectable options depicted on FIG. 13 allow refinement of the link pattern choices. For example, a user may want to use aliases or synonyms so that “equine” is also linked when “horse” is the primary pattern. Functionally, generating valid links automatically as depicted by block 407 of the database index generation process of FIG. 4 is a two step process. First, the virtual list of link pointers (words and patterns) is checked each time a word is extracted in block 405. If the word is on the list, the virtual list of all the files that will be in the final database (that is, a virtual table of contents) is checked to determine if a link target exists for the link pointer. For example, a pattern of “# S.W.2d #” might match a potential link pointer of “877 S.W.2d 200” that designates a file with a field likewise containing “877 S.W.2d 200” as the target. However, if the target file is not in the virtual table of contents, the pattern will not be designated as a link pointer. This avoids having link pointers that have no target being created. Generating valid links from patterns requires knowing the potential link pointers associated with specific target files. If a target file exists in the virtual table of contents, the link pointer can be inserted during the first pass through the files. The process is simpler in the case of words becoming link pointers. The virtual table of contents is examined to determine if the target file for a word is included. If so, a link pointer is created when the specified word is encountered. As with link patterns, the validity of all links is assured because no link is created before the existence of its target is established. At block 410, the master word index 202 is then compiled with the index of word locations. Block 411 entails assigning unique numbers to every unique word in the database which produces the word number index 203 having its two parts, the DSI 204 and DSF 205. Based on the data collected, the generator program's jump link index is compiled at block 412, resulting in the jump link list 206 having its two parts, the OAI 207 and the OAF 208. At next block 413, the word lists 214 are generated, resulting in the WDL 215, the WDN file 216, and the WDR 217. The fields list 212 is then generated at next block 414 to include the individual presorted lists CO1, CO2 . . . CO# 213. The contents tables 209 then are generated at next block 415 to include the COI 210 and the COF 211. The generator program returns to the start dialog allowing a user to generate another database's index or to exit. A graphic user interface (GUI) embodiment of a database application program according to the present invention will now be described which provides utilities for database index generation and database selection and searching. The following FIGS. 5-15 are exemplary screen shots at various stages of the database application program in order to demonstrate the principles of the present invention. The database application program may be executed on the computer system 100, where each of the screen shots or displays are displayed on the display 112 and viewable by a user of the computer system 100. The GUI database application program may comprise a more specific embodiment of the system 170 shown in FIG. 1C, and may further incorporate the principles described in relation to the flow diagrams shown in FIGS. 3 and 4. FIG. 5 is a screen display illustrating an exemplary database registration dialog of a graphic user interface (GUI) embodiment of a database application program implemented according to the present invention on a computer, such as the computer 100. The screen display includes a view options button 500, a database generator button 501, a search button 502, a database display window 504 which provides a list of database names 503, a Register New Database button 505, an UnRegister Selection button 506, and an Enable Word Lists control 507. The database display window 504 shows that four databases are registered as a result of previous use of the Register New Database button 505. As indicated by associated checkmarks 508, three of the registered databases have been selected. For example, a database may be selected when the user performs a standard operation with the mouse 114 by clicking a button on the mouse 114 while a cursor is on the database name, thus, causing a checkmark 508 to appear adjacent to the database name 503. FIG. 6 is a screen display illustrating an exemplary unregister confirmation dialog 601 of the GUI database application program introduced in FIG. 5 that appears when a user has highlighted a database name 503 and then selects the UnRegister Selection button 506. The unregister confirmation dialog 601 presents the user with an unregister confirmation message 602 that reminds the user of other options that are available. A message box 603 presents the user with various messages according to the position of the mouse pointer. A message 604 is shown in the message box 603 when the mouse pointer hovers over a Cancel Unregister button 606. The message 604 in the message box 603 changes when the mouse pointer is moved to other positions such as over an Unregister ONLY button 605, over a Delete Database Index Files button 607, or over a Delete All Files In Database button 608 to perform the indicated functions. FIG. 7 is a screen display of an exemplary index generator dialog of the GUI database application program introduced in FIG. 5 as it might appear after a user presses the database generator button 501. The index generator dialog includes a source file location edit box 700, a database output directory edit box 701, a generator type selection box 702, a set link properties or Linking button 703, a New Database Name edit box 704, a Register New Database check box 705, an enable Pause feature button 706, a Run button 707, and an Exit button 708. The index generator dialog is used for registering a database or regenerating the database index 200 from a previously registered but changed database. Should the user press the Run button 707 without changing any of the FIG. 7 parameters, the database indicated is registered and appears as shown at 503 in the database display window 504. If the database has already been registered, the database index 200 is regenerated when the Run button 707 is pressed. Checking the register new database check box 705 causes the generator to register new databases or to reregister changed databases and add them to the database display window 504. A user might choose to regenerate a database index in this manner if any of the source files in the source file location edit box 700 have been changed or if any files matching the generator type selection box 702 were added or deleted. The Pause button 706 toggles a feature that allows the user to suspend database processing indefinitely. When the pause feature is disabled, the generator completes its tasks faster. Database indexes are made from documents or files located at a path to a directory or folder indicated in the source file location edit box 700 and according to the file type indicated in the generator type selection box 702. If the documents of the database index are located remotely, e.g., on the World Wide Web (WWW) of the internet, the source file location edit box 700 contains a hypertext transfer protocol address, i.e., an “http” (HyperText Translation Protocol) address to the location. Of course, other types of addresses/designations are available for remotely accessible files, and these various types of addresses/designations are entered into the source file location edit box 700 in a similar manner. A database index is placed in the location shown in the database index output directory edit box 701 when generated from the selected files. Before pressing the Run button 707, the user can press the Linking button 703 in order to cause the documents of a database to have custom links to one another automatically generated at the same time the database index is generated (see FIG. 11 and related discussion). However, in order to understand searching operations of the software of the invention, at this point it is assumed that links have already been set and a database index has already been generated. FIG. 8 is a screen display of an exemplary search/retrieval dialog of the GUI database application program introduced in FIG. 5 that is displayed when a user presses the search button 502. The search/retrieval dialog presents the user with a search expression edit box 803 in which the user enters search terms of interest. In this case, the search terms “second amended petition” (including the quote marks) have been entered into the search expression edit box 803. The search expression edit box 803 supports search expressions of any degree of complexity by using the following techniques: parentheses; phrases set off by double quotations; proximity expressions; single- and multiple-character conflation in any combination of leading, middle, and trailing conflation; and default or overriding explicit Boolean operators, such as AND, OR, XOR, etc. Other search expression techniques are also contemplated. In addition, the search/retrieval dialog includes default Boolean operator controls 805 to determine how the system interprets multiple words entered in the search expression edit box 803. For example, if only two terms are entered without being surrounded by double quotation marks and the default Boolean operator is AND, the system finds all occurrences of both terms in documents that contain both terms. If the default Boolean operator is set to OR using the same example, the system finds all occurrences of either term in all documents with either term. If the default Boolean operator is set to XOR, the system finds all occurrences of either term only in documents that contain one term but not the other. Further, when checked, a Search within current results box 801 causes the system to perform the search called for in the search expression edit box 803 only for those documents found by the previous search. Once search terms are entered into the search expression edit box 803, a search of the database indexes for each of the selected databases 503 is performed by the search module 183 when an Execute button 806 is pressed. Further, the Execute button 806 causes all selected databases 503 to have instructions applied such as where to position a document when viewing it on the display 112, how to order search results, etc. For example, some instructions are set with a Document Position control 800 that designates whether the document, when a View button 810 is pressed, is displayed from its first line at the top of the document or from the location of the first search term that was found. Further, an Order Search Results By control 802 determines the sort order for the list of documents found that are to be displayed in a documents found window 815. If a Display first document found checkbox 804 is checked, the system displays the first document found that satisfies the search expression without the intermediate display of the completed search results. After the Execute button 806 is pressed, the system records and displays its progress in a Search terms found window 809 and includes the number of documents found that match the search criterion. After all documents satisfying the expression are found, a document number is displayed in a document counter 807 and the documents found window 815 is populated in the order indicated by the order search results by controls 802. The View button 810 causes a highlighted document 812 to be displayed according to the Document Position control 800 setting. Should the number of documents found exceed the number that can be displayed in the documents found window 815, a scroll bar, the down arrow, and the Page Down keys are available so that the user can see the other documents found. Since a database application program, in one embodiment, is configured to simultaneously search over two billion databases, each with over two billion files, and each file with over two billion characters, the user may want to stop a search after it has started. For that reason, a Stop button 808 is provided. Further, a Clear button 811 allows all data to be cleared from the search expression edit box 803, the search terms found window 809, and the documents found window 815. If the Enable Word Lists control 507 is enabled, a Word List button 814 is enabled. When pressed, the Word is List button 814 causes a list of all words that appear in all selected databases 503 arranged in alphabetical order to be displayed. Words can be placed directly into the search expression edit box 803 from the word list. A Close button 816 closes the search/retrieval dialog and returns the user to the previous screen without taking any further actions that may be available. Finally, a Sort Again button 813 is used to repeat the above procedure after changing the terms in the search expression edit box 803. FIG. 9 is a screen display of an exemplary dialog displaying a document, such as the highlighted document 812, retrieved from among the documents indicated in the documents found window 815. A document display window 928 displays text and graphics of a selected document being viewed in a similar manner as it would be seen in a word processor application such as MS-Word or the like. A word wrap button 921 toggles between two display states. The first state shows text as wrapping to the next line when the right side of the document display window 928 is too narrow to show all of the text in a paragraph on a single line. The second state of the word wrap button 921 displays all the text in a paragraph on a single line, and, if necessary, a horizontal scroll bar appears at the bottom of the document display window 928 which allows the user to move the contents of the window to see any portion of the text. This second state of the word wrap button 921 is especially useful when viewing documents with table type data where columns were determined by use of tabs or spaces. Since most computers use a proportional font to display text, such table type data may not align properly unless a fixed-pitch, non-wrapping display format is used. The word wrap button 921 allows the user to instantly toggle between either display format as desired. A field link 925 is illustrated in the text in FIG. 9, in which the underlying text is shown highlighted with selectable color and font different from the surrounding text to indicate the link, where the highlight selections are made in a Search Terms display control 1011 (FIG. 10). When the user double clicks on the field link 925, the system displays the document that the field link 925 targets. To return to the text displayed, the user need only press a jump backward button 916. The document display window 928 then shows the text of the document 812. A found terms display 927 shows that two terms were found in the highlighted document 812 of the documents found window 815. The same information about the document 812 is accessible through activation of a title bar 906. The Document Position controls 800 were set to display the document at the first search term, and the order search results by controls 802 were set to sort the results by database name 503. A database named “RTF12231” is the first one shown in the selected databases 503, and the system assumes that the user prefers that order. The search expression edit box 803 shows that the phrase “second amended petition” was searched for, and the document display window 928 shows two instances 926 of the phrase appearing near the center of the screen display for user convenience in determining the context of a term. The terms of the phrase are shown in font attributes determined by the Search Terms display control 1011. The previous search term button 911 is not available because the first search term in the document is displayed and current as indicated by a text cursor 950. The next search term button 912 is available because there is one more instance 926 in the document. Both the next document with search terms button 915 and the previous document with search terms button 914 are shown as available because the document displayed is the thirteenth of forty documents found as shown in the document counter 807. Also shown in the document display window 928 is a phrase 909, “Texas Rules of Appellate Procedure”. The phrase 909 is shown in bold italics to indicate that it has a legal pad note attached to it, where the bold italics is determined by a LegalPad Notes display control 1009. Legal pad notes allow a user to create reference notes that are accessible from a document in a manner similar to document access through the field link 925. The LegalPad Notes display control 1009 shows that bold italics is used when the system displays text where legal pad notes are attached. As discussed in relation to FIG. 12, a legal pad button 918 is used to create new legal pads from highlighted text. A SmartScreen button 900 causes the system to display the same screen shown when the database application program is started (initialized) as in the example embodiment of FIG. 5. The first document in universe button 901, the “universe” including all files/documents in all selected databases, is not available and thus not highlighted because the document shown in the document display window 928 just happens to be the first document in al of the documents in the selected databases. The same situation applies to a previous document in universe button 902, which is also not highlighted. However, a next document in universe button 903 is available as indicated by being highlighted. When the button 903 is pressed, the document following the one currently displayed is displayed. When pressed, a last document in universe button 904 causes the system to immediately display the last document in the list of all of the selected databases 503. Further, when pressed, a table of contents button 905 displays a dialog with collapsible table of contents to allow a user to quickly determine and view any file in any of the selected databases 503. The find document in entire universe button 907 displays a dialog allowing a user to type fragments of a sought document in order to find it and quickly view it. A find button 908 allows a user to search within the document currently displayed. A direct from text button 910 causes a phrase search to immediately be executed for all text that is selected by a user and highlighted. It is not available unless some text is selected. A bookmark button 917 allows a user to place an electronic bookmark at any point in any document through a dialog that allows the user to name and manage bookmarks. A copy button 919 allows the user to copy any highlighted text to the computer's memory for insertion elsewhere. A print button 920 displays a print dialog which provides full print utilities to the user. A font change button 922 allows the user to toggle from a proportional pitch font to a fixed pitch font for ease of viewing text formatted with spaces and tabs for columnar alignment or back to the original font. A help button 923 displays information about the system. An exit button 924 causes the system to terminate and asks the user whether data about the session should be saved or not. In summary, the document display window 928 illustrates examples of field links 925, legal pad phrases 909, and instance 926 of search phrases. The appearance of these portions of the document display window 928 is controlled by a display options dialog that is discussed in relation to FIG. 10. FIG. 10 is a screen display of an exemplary display options dialog, i.e., a view options dialog 1012, of the GUI database application program introduced in FIG. 5 that appears when a user has pressed the view options button 500. A FastSearch button 1002 allows the user to set a variable that controls the speed with which the system preloads certain index components when it is started. Colors and Styles controls 1001 enable the user to set display options for the document display window 928. For example, a Document Background screen color box 1000 is used to select background colors of the document display window 928. Further, a Jump Tags section 1006, a LegalPad Notes display control 1009, and the Search Terms found section 1011 are available in the view options dialog 1012, each for selecting the color, weight, and font of the text in the document display window 928. The effects of each control are immediately shown in the window appearing below the Colors and Styles controls 1001. A Default Text Font Size 1003 is set by the user. Pressing a Restore Defaults button 1005 resets all controls to their original state. Pressing an OK button 1004 accepts any changes the user has made and restores the display to the document display window 928, where the text of the document is displayed with the new display settings. In this manner, the user selects the highlighting functions, such as font options, colors and styles, for text to be highlighted from background text for text of interest, such as jump tags, legal pad notes, search terms, etc. FIG. 11 is a screen display of an exemplary link generator dialog of the GUI database application program introduced in FIG. 5 for creating links between documents such as field link 925. A user can instruct the database index generator to insert custom links by entering a custom link word in a New Custom Link Word edit box 1101 and then entering a path and name of a file or document to which all such words should link in the File To Link To edit box 1102. For user ease and convenience, the path and name of the file to link to can be selected using the browse utility provided by pressing a Browse button 1103. When the user presses an Add New Link button 1104, a custom link word and file to link to pair are displayed in a custom link display window 1100. An essentially unlimited number of such pairs can be created. After the database index 200 is generated by pressing the Run button 707, whenever a user encounters the custom link word in any document displayed in the document view window 928, except the corresponding file to link to file, it is set off from surrounding text according to the display view options set by the Colors and Styles controls 1001. When the user double clicks such a word, the database application program immediately displays the file that is specified by the user as the linked file. To return to the previous document at the previous position, the user need only press the jump backward button 916. The jump backward button 916 allows the user to retrace any number of forward jumps. The link generator dialog of FIG. 11 also allows a user to instruct the database index generator to insert field links that are based on link field patterns. A field link based on a link field pattern is a pattern sequence found in a file that exactly matches the same pattern sequence that is found in the appropriate field in another file in the database source files. To create these types of field links, a pattern is entered into a New Link Pattern edit box 1106. When the pattern of the New Link Pattern edit box 11106 matches another pattern located in a certain field of another file, a field link can be created between the files. The “certain field” of a file that is linked to corresponds to a link field number that is selected in a Link Field Number edit box 1107. After the pattern is entered into the New Link Pattern edit box 1106 and the link field number is entered into the Link Field Number edit box 1107, in this case “1”, an Add New Link button 1108 is pressed and the database index is updated with the new information. The resultant field link pattern corresponding to the link field number then appears in the link field pattern window 1105. Advantageously, a pattern entered into the New Link Pattern edit box 1106 can use “wildcard” characters. Wildcard characters are characters such as %, ?, *, and #, where each of the characters has a special meaning. In the embodiment shown, the “%” character substitutes for any digit, the “#” character substitutes for any integer greater than zero, the “*” character substitutes for any number of characters or digits between delimiters, and the “?” character substitutes for any single character. For example, a pattern “# s*d #” matches “9 sand 977”, “843 S.W.2d 955”, etc. An essentially unlimited number of field link pairs can be created. Of course, any number of wildcard characters may be defined depending on a particular embodiment. Also of note, files/documents have many different file formats for their respective fields (e.g., WordPerfect® format). These formats provide for normally hidden fields to contain data about the file such as title, subject, author, etc. A system according to the present invention provides for placing visible fields in the first line of the file with each field separated by a delimiter such as a tab character. After the database index has been generated and when the user encounters a field link in any document displayed in the document view window 928, it is set off from surrounding text according to the display view options set by the Colors and Styles controls 1001. When the user double clicks such a field link, the system immediately displays the linked file. To return to the previous document at the previous position, the user need only press the jump backward button 916. If the database index generator has previously generated an index for a particular source file location 700, database Output Path 701, and the New Database Name 704, the linking control panel settings used previously are automatically loaded. If the user wants to migrate linking control panel settings from any previous instance, pressing a Retrieve Settings button 1109 causes display of a list of all such instances, and the desired one may then be selected and used. An Options button 1111 causes a optional field links dialog 1300 (see FIG. 13 and related discussion) to be displayed and makes additional options available to the user for creating a custom field link. Finally, pressing an OK button 1110 indicates that the user has completed customizing the field links and instructs the database generator to use the settings in the link generator dialog when creating the database index. Of course, the database index is not created until the Run button 707 is pressed. FIG. 12 is a screen display of an exemplary legal pad dialog implemented as an integrated word processor of the GUI database application program introduced in FIG. 5. As stated, the legal pad button 918 is available when text of a document has been highlighted by the user or when a legal pad entry exists for any document in any of the selected databases 503. Pressing the legal pad button 918 displays the legal pad dialog shown in FIG. 12. If some text was highlighted before the legal pad button 918 was pressed, the system assumes that the user wants to create a new entry. The next sequential note name is automatically assigned in the note name edit box 1200, but the user can change it to whatever is desired. Existing note names are shown in a note name window 1201. The user can copy or write any text into a Legal Pad Entry Text window 1205. Note Type controls 1202 allow the user to designate whether the note is to be available to other users or to have restricted access. A Lock button 1203 allows the user to prevent any modifications to the note displayed in the Legal Pad Entry Text window 1205. A Locate button 1204, when pressed, displays the document at the position where the note is attached. The original text that was highlighted when the legal pad button 918 was pressed to create the note is displayed with the font and color attributes set by the legal pad notes section 1009 as shown by the example phrase 909. A Delete button 1212 allows the user to delete a note. A Rename button 1211 allows the user to change the name of a saved note. An Export button 1210 allows the user to save the note to an external file on any drive available to the computer. A Save button 1206 allows the user to save changes to the note without changing the current display. A Print button 1207 causes a print utility dialog box to appear enabling the user to print the current note. A Close, Save Changes button 1208 allows the user to save changes to the note and return to the document being viewed. A Close, Cancel Changes button 1209 causes any changes to the current note to be discarded and the system returns to the display as it was before the legal pad button 918 was pressed. FIG. 13 is a screen display of an optional field links dialog 1300 of the GUI database application program introduced in FIG. 5 that is displayed when the Options button 1111 is pressed. The optional field links dialog 1300 includes additional options that are available to the user for creating custom field links. An Alias Control section 1301 allows the user to define an unlimited number of aliases in a Current Aliases window 1303 for a link term so that strict correlation between terms linked to target files is not necessary. For example, whenever the term “vine fruit” appears in any of the database files, the user may want the term to be linked to a glossary file that defines the term. By setting or defining aliases for “vine fruit” to include alias terms “grape”, “tomato”, and “raspberry”, those words also have a link generated to the glossary file just as “vine fruit” does. Pressing an OK button 1302 sets the options and restores the display of the linking control panel to its previous state. In addition to the above described example embodiment, FIG. 14 is an example screen display of a Browser Mode Window showing an HTM document retrieved from the internet using the GUI database application program introduced in FIG. 5. The Browser Mode works in a similar manner as commonly used browsers, such as Netscape Navigator or Microsoft® Explorer. The internet address of the document is shown in an Address bar 1405. If the user puts the cursor (or focus) on the Address bar 1405 and presses the Return or Enter keyboard key, or presses a Refresh button 1404, the document would again be retrieved from its internet source. By pressing a Back button 1400, the Browser Mode Window displays the previous document that was viewed. By pressing a Forward button 1402, the Browser Mode Window displays the document that was previously viewed before the Back button 1400 was pressed to display the document shown. Pressing a Stop button 1403 terminates any internet retrieval action currently underway. Pressing a Home button 1406 causes the Browser Mode Window to retrieve and display the document at the specific internet address designated as the “Home Page” for the Browser Mode Window. Pressing a Search button 1407 causes the Browser Mode Window to retrieve and display the internet search engine page designated by a user option in an Options dropdown menu 1401. A Print button 1408 allows the user to print the document displayed and to set printing options in a dialog box that is displayed. A DB Name button 1409 displays a dialog box and list of previous database names that have been used. The current database selected is shown in a database name label 1412. A more extensive dialog box that allows the user to change other database particulars is also available as a user option in an Options dropdown menu 1401. A SpeedSave button 1411 immediately saves the displayed document, along with all of its pictures, graphics, images, hypertext links, and layout into the database named in the database name label 1412. The first time the SpeedSave button 1411 is pressed in a session of the software, the same dialog displayed by pressing the DB Name button 1409 is displayed to safeguard against the user inadvertently saving a file into a forgotten about database. Double clicking the database name label 1412 also displays the same dialog. Depending upon the settings for the database particulars accessible under the Options dropdown menu 1401, the file can be saved as a normal is “Text” file, an HTM file without images, an HTM file with images linked to their internet source, or an HTM file with all images retrieved and saved on the local computer's hard drive. Pressing an Exit Browser button 1410 causes the software of the system 100 to create a fully indexed and searchable database of all files saved into the database name shown in the database name label 1412 according to the default behavior. The database is automatically registered and shown on the database display window 504. The default behavior can be changed to accommodate a variety of user preferences through the appropriate selection on the Options dropdown menu 1401. A document location label 1413 indicates to the user whether the source of the document being viewed is remote or local, and the label 1413 changes automatically when the viewed document changes its source. A status bar message 1414 changes as appropriate to give the user information about the status of the Browser Mode Window. A Browse Mode label 1420 indicates to the user whether the software is functioning in its Browser Mode or its Viewer Mode. The document depicted in FIG. 14 has several elements referenced in order to illustrate the capability of a system according to the present invention for allowing the user to easily edit content and arrangement of documents saved in the Browser Mode. For example, FIG. 14 illustrates a “Contact Information” graphic 1415, a “What's New” graphic 1417, a “Services” graphic 1418, a Footer Text 1416, and a Body Text 1419 which have all been manipulated, deleted, or changed as shown in FIG. 15. FIG. 15 is an example screen display of the HTML document of FIG. 14 after being saved and edited in the Browser Mode window. FIG. 15 shows the “Contact Information” graphic 1415 as having been moved in the left column of the document, which is now shown as Contact Information graphic 1500. The “What's New” graphic 1417 and the “Services” graphic 1418 have been deleted. A new “Super Sweeps” graphic 1503 has been added. The Footer Text 1416 has been moved to be the first paragraph of the document's new body text. The Body Text 1419 has been moved down and edited to delete the text “(“IDC”)” from it. Since the internet address shown in the Address Bar 1405 of the document of FIG. 14 has been saved, the Address Bar 1501 has changed to a pathname to reflect the document's location on the local computer's hard drive. The document location label 1413 indicating “internet” has also changed to be Document Location Label-1502 indicating “Local” to help ensure that the user knows the source location of the document being viewed. The editing process automatically makes all adjustments to HyperText links and other HTM codes associated with text or graphic elements that are added, deleted, or moved. When the SpeedSave button 1411 is pressed, the edited file is saved after the user selects an option to save it under a different name or to replace the existing file. In accordance with the present invention, the disadvantages of the prior art have been overcome through the implementation of a system and method for creating at least one customizable database index for assisting in navigation of at least one database. The system includes a database index generation module that enables a user to specify at least one database for access by the user. The at least one database includes at least one document. Also included is a database index generator module that enables the user to generate a customizable database index associated with the at least one database. Further, an integration tool is included that enables the user to add references of additional databases to the customizable database index and to modify references of existing databases in the customizable database index. Also commonly included is interconnection logic that enables the user to place links within the customizable database index such that the user can cross reference one of the at least one documents from the at least one database with another of the at least one documents of the at least one database. Another implementation of the invention uses multiple external search engines during the same search. Each search engine typically requires a different syntax to do a search. When activated, each search engine responds with different search results. The results may have different contents and formats and priorities. The results may include graphics and text that are not relevant to the information sought by the search and are therefore extraneous. The invention rejects discernable extraneous information by taking advantage of the communication method by signaling the search engine that the unwanted results are already received so they are in fact never sent. Non-discernible extraneous information is filtered out and discarded. The remaining results which are received often include duplicates which are initially compiled into lists of all results. The lists are then compiled into a single list without duplicates. The list is prioritized and presented to the user as a single, prioritized list for viewing. The list contains checkboxes that the user can check to select documents which the invention will retrieve and put through the storing and indexing processing for search and retrieval. When the user positions a mouse pointer over a URL on the list, a popup window is generated that displays the text, so the information can be screened to ascertain if it contains relevant information to the search inquiry. If the text contains relevant information, the user can then check the box for selection for downloading and insertion in the database. The above-listed sections and included information are not exhaustive and are only exemplary or the invention. The particular sections and included information in a particular embodiment may depend upon the particular implementation and the included devices and resources. Although a system and method according to the present invention have been described in connection with the preferred embodiments, it is not intended to be limited to the specific form set forth herein, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the invention as defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Computers were intended to provide an effective and efficient way for humans to manage, locate, peruse and manipulate data or objects. For example, a first, basic system and method is that demonstrated by modern word processor applications which have some search and text access capabilities, however, as far as in known, they are limited to the current file that is open. Employing this method, the user can request the location of a word in the text. Within an individual file, the computer will then take the user sequentially to each location of that text. Only string searches are allowed. By repeatedly running the search, the user can sequentially move from result to result. While it might be possible to open, many files simultaneously, the available resources and memory make this impractical. A second, improved system and method enabled by some computer operating systems include applications that allow users to search all available files, accessible by certain software applications, for words or simple phrases. They still require the user to open each of the files of interest in a word processor, viewer or other application referred to in the first system and method to access the data. The search time required is relatively great because the data available has to be sequentially read and compared with the query. A third system and method used by software applications provides improved search capabilities and is commonly known as a “search/retrieval engine”. Among other things, search/retrieval engines can essentially search and access many thousands of files simultaneously and very quickly by using pre-generated indexes of the data. For example, a user can query an encyclopedia converted to an indexed database, and by the use of highlighted text, quickly determine every place a word or phrase occurs in the text, and have the ability to instantly view those occurrences as desired. These products even take the user sequentially to each incident of highlighted text or “hit.” The computer can then take the user from hit to hit. Converting a database like an encyclopedia into a format useable by a search/retrieval engine is not simply a matter of converting its volumes into electronic files accessible by the user's computer. For efficient search performance, the contents of the files are logically indexed as to location, frequency, etc. The search functions of the engine actually search the index to determine if the query criteria are met, and then the locations of valid results are passed to the retrieval functions to display them. Without a well-designed index, a computer could take a long time to perform a search for a simple phrase that can otherwise be performed in a fraction of a second. Some search/retrieval engine application vendors allow users to generate indexes for their own files through an indexing utility, and others intend for indexing to be done only by electronic database publishers by use of a separate application designed for that purpose. Currently, a user desiring to employ the speed of a computer to search for and retrieve data from multiple disparate source files generally has three choices: (1) use the basic first system and method above to open each file in a word processor application and search them individually; (2) use the second system and method above, search each file using an operating system application, and then open each file in the list of results in a word processor application; and (3) obtain an indexed database of the sources along with a search/retrieval engine from an electronic publisher, or create a database usable by a search/retrieval engine. As far as is known, no application has been devised, however, to adequately deal with the internet and yield the results described in the third system and method above. The internet is a vast and burgeoning source of information concerning nearly every subject. But the internet is comprised of files available in SGML and its derivatives including HTML and XML and other hypertext type formats. A hypertext markup language such as HTML is a structured, yet ambiguous language. In this application, reference is generally made to HTML files and documents, which is the most common format. However, it is understood that this includes the SGML format and its other derivatives, including XML and future modifications, implementations, and standards for use in data files, databases and the internet. As far as is known, having a computer automatically and accurately determine the exact location of text within an HTML type formatted document, object, or file is not accomplished in the prior art. Consequently, there is no known practical method or system whereby a user can efficiently and effectively use a computer's speed to search for and retrieve data from a set of files accessible by the computer and get pinpoint, highlighted display of the designated text. It should be noted that the information desired may be in files, objects, or files that are unknown, and available to the user. In addition to the internet, many enterprises have extensive repositories of information stored in electronic form that may contain information an authorized user may desire and want to locate and access. Even at the lowest level, an individual computer generally contains unknown or forgotten data that the user would find valuable. All of these repositories of information cannot be as efficiently accessed by the current art as is desired. Using the current art in the third system and method above, users can add electronic bookmarks to enable them to quickly return to any part of any volume of an encyclopedia, referred to in the example above, and they can copy portions for insertion into other documents of their own creation. By use of hypertext links appearing within the database, a user is able to instantly view related data for which he had not searched. The links are generated according to a rationale applied when the database index was prepared. Adding hypertext links usable within a database is generally a more complex process. The links are intended to appear to the user in a color or format distinguishable from other data, and when activated, the computer is directed to display another highlighted portion of the database. By naming the instructions to the computer within links as “pointers” and what they link to as “targets”, the process will be facilitated. A database can theoretically have an unlimited number of identical pointers (even though what the user sees can be different for some or all of them), but any pointer can generally only have one target (a specific area of the database to display), and targets are invisible to the user. Links must be sensitive to the context of the document and context sensitivity requires intelligence. Thus, adding links to a database requires human intervention because current computers inherently lack any intelligence. Although simple linking based upon discernible patterns within text and is targeted toward files matching those patterns can easily be done programmatically, human intervention is still required to design and initiate the process. Further, such favorable linking circumstances rarely exist within typical, disparate data and even greater human intervention is required. Consequently, search/retrieval engine vendors essentially leave linking up to the creator of the search engine software or electronic publisher to do manually, and the links are generally not customizable by the user. Thus, the vendors commonly provide technical specifications on how to craft pointer and target codes for the software and how to write programs to link their unique databases. However, some word processing and other applications permit users to craft links among compatible files using manual processes. If a user desires to have the searchable data include context-sensitive links, the choices are generally reduced to: (1) obtaining a pre-linked database from an electronic publisher; or (2) creating a custom database and manually inserting links individually or by use of a custom program written for the unique situation. Beyond the problems of availability and lack of customization, a fundamental problem with the first choice is that a publisher may not consider the same links to be important as a user does. Thus, the publisher may include links that are not important to the user and may not include links that would have been important. A fundamental problem with the second choice is that manually inserting links requires a substantial amount of time and trouble that quickly outweighs any potential benefit to manually inserting links as the quantity of data increases. As far as is known, the current art does not include a system to create links by designating “pointers” and “targets” and having the program automatically create links that are all valid. It would be highly beneficial to have the results from computer searches of various sources of information that locate information from the various sources, to be quickly and easily saved locally for accessing at a later time, without having to redo the search and re-access the sources of information. This saves search time and repeating the search, which may not locate the previous information. The locally saved information can also be quickly accessed without having to relocate the information. An object of the invention is to allow someone to create his or her own custom, organized database that can be utilized effectively. Each time relevant information and files are located, they can be put into a database, indexed and made available for use. The limitations of prior systems are overcome by the present invention, which is an improved method and system for acquiring, creating, manipulating, indexing, and perusing data, and for locating and retrieving known or unknown data for the same purposes. In a preferred embodiment, the system is a stand-alone application residing on a user's personal computer that enables the user to create fully searchable databases or local sources of any size from any electronic documents accessible by the computer and selected by the user. It also enables the user to accurately and methodically locate undiscovered documents that may be of interest. By use of a word processing means integrated into the application, it enables the user to create and include new documents into the database or to create retrievable documents within the application. Any databases or documents that the user creates can be password protected to restrict access by unauthorized users who may have access to the computer. The invention provides a user with the ability to train a search engine to automatically and methodically search the internet or other data sources according to derived or evolved limitation criteria. Each set of such criteria is stored for reuse or modification as the user desires. Without limiting the criteria, the system could be directed to retrieve and completely index every file that existed on its available data sources. While that would guarantee that all data in those files would be searched for data that the user wants, there are practical limitations. If the data source is vast, like the internet, the system would attempt to index all of its files, objects, or documents, but it would quickly encounter storage limitations on the user's computer if default limitations were not automatically imposed. By artfully estimating the time and storage requirements and matching them to available resources, the system guides the user to impose limitations to produce the desired results. This method allows users to completely index all of some data sources, to filter and sort smaller percentages of greater data sources, or to survey large data sources such as the internet. In the latter case, the user can refine the resultant survey to identify smaller, but more relevant, parts of the data sources. After sufficiently iterating the refinement process, the user will be able to index and search all selected and relevant data. Thus, this system and method enable a user to predictably and efficiently solve the problem of selecting and comprehensively searching relevant data from sources with unknown content by combining human intelligence with the indexing and search/retrieval capabilities of a computer. Since the system can be trained to repeat all or parts of previous actions, the user's instructions can be perfectly carried out while repeatedly using different search criteria. Uses of the system include those identified herein as well as many others. For example, a vendor could prepare a database, kept on a remote server that contains continually updated information, to be accessed by a computer running this system. Among other things, the database could contain information authorizing the user to continue to use the system and query the database. Independent of the server, the user could then employ all or part of the system's capabilities for other purposes as desired. In one embodiment, commercial electronic database publishers could use a system according to the present invention as a publishing system to create databases with more or less homogeneous content. For example, one publisher may produce a monthly searchable, linked database containing issued United States patents, another might produce a linked database containing decisions of appellate courts, and another might produce a linked database containing documents required to be filed by various regulatory agencies, etc. Using prior systems to produce such databases requires substantial programming skills to incorporate reference links within the database, but in practice, many such links are invalid because a referenced document does not exist. Using the system according to the present invention does not require such skills because it automatically creates only valid and verified links. The graphical user interface is easily modified to comport with a particular “look and feel” desired by the publisher. In another embodiment, a data provider could maintain a continually updated database of information (e.g., statistical or a glossary) on a remote server that the user accesses via a network such as the internet. Upon being started by the user, an application automatically connects to the remote database when information from the database is needed and disconnects once it is obtained. If the remote database has changed, the user will be notified and the user's database index can be regenerated to accommodate the changes. By storing user authorization codes on the remote server in a database or table for that purpose, the provider can verify that the user is still entitled to access the service provided. The application on the user's computer can automatically be rendered dysfunctional by the passage of time unless it successfully renews its operating status by connecting to the provider's authorization code database. This embodiment provides advantages to both the data provider and the network service provider: (1) the system application can essentially be provided on a subscription or rental basis without the necessity of distribution media or elaborate license or copyright protection schemes; and (2) the network service provider's effective bandwidth is greatly increased because the system only connects to the remote server on an as-needed, when-needed basis instead of requiring an active modem connection continuously. Another object of the invention is to provide a method and system for storing search results from various sources including the internet with internet format files, objects, or documents. The locally stored results can be automatically indexed for fast searching and hyper linked by the user to make subsequent finding of the previously located information quick and simple The system and method of the invention overcomes the above-noted problems of the prior art and can be used for general purpose data acquisition, creation, manipulation, indexing, and perusal while connecting to remote data sources only as needed. | <SOH> SUMMARY OF THE INVENTION <EOH>A data acquisition and perusal system and method according to the present invention includes a database selection module, a link module, a database index generator module and a search module. The database selection module enables selection of a plurality of files, objects, or documents for inclusion into at least one selectable database. The link module enables custom links to be defined between selected terms of selected files of the selectable database. The database index generator module enables generation of a searchable index of the data contained in the selectable database including the custom links so that the searchable index includes only valid links. The search module enables a search to be performed of the searchable index according to a search criterion. The plurality of different files may include a plurality of different file types, such as internet formatted files, objects, or documents, including HTML type formats, and word processor formats, text formats, RTF formats, etc. Generally, each database includes one or more files of a particular type. The database selection module may be configured to enable selection of the plurality of files both locally and remotely via a network. For example, the data acquisition and perusal system and method may be implemented on a computer coupled to a network, where the network may further be connected to the internet. The data acquisition and perusal system and method may be configured to copy internet files to a local storage disk, or to simply maintain a link to the internet files of interest. The link module enables association of any selected link term with any of the plurality of files in the selectable database. The link module may further enable at least one alias term to be defined for any selected link term to enable a link to be established between each alias term and any of the files in the database. Each of the files may further include one or more fields. The link module further enables field links to be defined between any two or more of the plurality of files. Such field links may be defined according to patterns, where the patterns may further be defined using wildcard characters that each replace one or more digits or characters. The search module may further enable sorting of any files of the selectable database that meet the search criterion. In one embodiment, such sorting may be according to the respective fields of the files. For example, the files may be sorted by date, by name, or by any other field types or descriptions. The data acquisition and perusal system and method may further include at least one input device and a display utility including a graphic user interface (GUI). The input device and display utility enables graphic interaction with the database selection, the link, and the search modules via the input device. The display utility displays at least portions of files in the selectable database that meet the search criterion. The portion of a displayed file typically includes any text that meets the search criterion. Such text is usually graphically indicated, such as via color, style, highlighting, etc. Also, any selected link terms defined via the link module are also indicated in a similar manner. Further, the display utility enables interaction with any indicated selected link terms via the input device to enable perusal of linked files in the selectable database. For example, a user may double click on highlighted text indicating a link term in a displayed file, where the data acquisition and perusal system and method jumps to and displays the linked file. Operation is similar for alias link terms if defined. The system and method may automatically, unambiguously, and accurately place reference links among documents within a database it creates according to a schema controlled by the user. These links enable the user to instantly view a file, object, or document referenced by another file, object, or document currently being viewed and to backtrack to any point of origin in the database. The system and method does not modify or make extraneous copies of the contents of the original database files, objects, or documents. If a file, object, or document is modified or deleted, the integrity of the database is not affected with respect to the other files, objects, or documents because either the database (i.e., the index) will be regenerated, or an error message will be presented telling the user that the file, object, or document has been modified or deleted. The application also may give the user the option to create compressed, password-protected databases for secure dissemination to other users or simply to secure the files, objects, or documents and database indexes for personal use. Embodiments of a system and method, in accordance with the principles of the present invention, provide methods and systems for acquiring, creating, manipulating, indexing, and perusing data; for locating and retrieving known or unknown data for the same purposes; for automatically connecting to remote network computers on an as-needed, when-needed basis; for validating a user's rights to use the system; and for securing pertinent data from unauthorized use. | 20040708 | 20101116 | 20050203 | 61570.0 | 1 | KHAKHAR, NIRAV K | DATABASE SYSTEM AND METHOD FOR DATA ACQUISITION AND PERUSAL | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,887,785 | ACCEPTED | Bronchodilating beta-agonist compositions and methods | Bronchodilating compositions and methods are provided. The compositions are intended for administration as a nebulized aerosol. In certain embodiments, the compositions contain formoterol, or a derivative thereof. Methods for treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders using the compositions provided herein are also provided. | 1. A pharmaceutical composition, comprising formoterol, or a derivative thereof, in a pharmacologically suitable fluid, wherein the composition is stable during long term storage and the fluid comprises water, and wherein the formoterol free base concentration is about 0.08 μg/mL up to about 128 μg/mL. 2. The pharmaceutical composition of claim 1, wherein the composition has an estimated shelf-life of greater than 1 month usage time at 25° C. and greater than or equal to 1 year storage time at 5° C. 3. The pharmaceutical composition of claim 1, wherein greater than about 80% of the initial formoterol is present after 1 month usage time at 25° C. and 1 year storage time at 5° C. 4. The pharmaceutical composition of claim 1 that has been nebulized. 5. The pharmaceutical composition of claim 1, wherein the pharmacologically suitable fluid comprises a polar solvent. 6. The pharmaceutical composition of claim 5, wherein the polar solvent is a protic solvent. 7. The pharmaceutical composition of claim 1, further comprising a tonicity adjusting agent. 8. The pharmaceutical composition of claim 7, wherein the tonicity adjusting agent is ammonium carbonate, ammonium chloride, ammonium lactate, ammonium nitrate, ammonium phosphate, ammonium sulfate, ascorbic acid, bismuth sodium tartrate, boric acid, calcium chloride, calcium disodium edetate, calcium gluconate, calcium lactate, citric acid, dextrose, diethanolamine, dimethylsulfoxide, edetate disodium, edetate trisodium monohydrate, fluorescein sodium, fructose, galactose, glycerin, lactic acid, lactose, magnesium chloride, magnesium sulfate, mannitol, polyethylene glycol, potassium acetate, potassium chlorate, potassium chloride, potassium iodide, potassium nitrate, potassium phosphate, potassium sulfate, propylene glycol, silver nitrate, sodium acetate, sodium bicarbonate, sodium biphosphate, sodium bisulfite, sodium borate, sodium bromide, sodium cacodylate, sodium carbonate, sodium chloride, sodium citrate, sodium iodide, sodium lactate, sodium metabisulfite, sodium nitrate, sodium nitrite, sodium phosphate, sodium propionate, sodium succinate, sodium sulfate, sodium sulfite, sodium tartrate, sodium thiosulfate, sorbitol, sucrose, tartaric acid, triethanolamine, urea, urethan, uridine or zinc sulfate. 9. The pharmaceutical composition of claim 7, wherein the tonicity adjusting agent is sodium chloride. 10. The pharmaceutical composition of claim 1, wherein the pharmacologically suitable fluid comprises a buffer. 11. The pharmaceutical composition of claim 10, wherein the buffer is citric acid/phosphate, acetate, barbital, borate, Britton-Robinson, cacodylate, citrate, collidine, formate, maleate, McIlvaine, phosphate, Prideaux-Ward, succinate, citrate-phosphate-borate (Teorell-Stanhagen), veronal acetate, MES (2-(N-morpholino)ethanesulfonic acid), BIS-TRIS (bis(2-hydroxyethyl)iminotris(hydroxymethyl)methane), ADA (N-(2-acetamido)-2-iminodiacetic acid), ACES (N-(carbamoylmethyl)-2-aminoethanesulfonic acid), PIPES (piperazine-N,N′-bis(2-ethanesulfonic acid)), MOPSO (3-(N-morpholino)-2-hydroxypropanesulfonic acid), BIS-TRIS PROPANE (1,3-bis(tris(hydroxymethyl)-methylamino)propane), BES (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), MOPS (3-(N-morpholino)propanesulfonic acid), TES (N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid), HEPES (N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid), DIPSO (3-(N,N-bis(2-hydroxyethyl)amino)-2-hydroxypropanesulfonic acid), MOBS (4-(N-morpholino)butanesulfonic acid), TAPSO (3-(N-tris(hydroxymethyl)-methylamino)-2-hydroxypropanesulfonic acid), tris(hydroxyrnethylaminomethane, HEPPSO (N-(2-hydroxyethyl)piperazine-N′-(2-hydroxypropanesulfonic acid), POPSO (piperazine-N,N′-bis(2-hydroxypropanesulfonic acid)), TEA (triethanolamine), EPPS (N-(2-hydroxyethyl)piperazine-N′-(3-propanesulfonic acid), TRICINE (N-tris(hydroxy-methyl)methylglycine), GLY-GLY (glycylglycine), BICINE (N,N-bis(2-hydroxyethyl)glycine), HEPBS (N-(2-hydroxyethyl)piperazine-N′-(4-butanesulfonic acid)), TAPS (N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid), or AMPD (2-amino-2-methyl-1,3-propanediol) buffer. 12. The pharmaceutical composition of claim 10, wherein the buffer comprises citric acid/phosphate buffer, acetate buffer, citrate buffer or phosphate buffer. 13. The pharmaceutical composition of claim 10, wherein the buffer is citrate buffer. 14. The pharmaceutical composition of claim 13, wherein the buffer concentration is from about 0.01 mM to about 150 mM. 15. The pharmaceutical composition of claim 13, wherein the buffer concentration is from about 1 mM to about 50 mM. 16. The pharmaceutical composition of claim 13, wherein the buffer concentration is from about 1 mM to about 20 mM. 17. The pharmaceutical composition of claim 13, wherein the buffer concentration is about 20 mM. 18. The pharmaceutical composition of claim 13, wherein the buffer concentration is about 5 mM. 19. The pharmaceutical composition of claim 8, wherein the ionic strength of the composition is about 0 to about 0.4. 20. The pharmaceutical composition of claim 8, wherein the ionic strength of the composition is about 0.05 to about 0.16. 21. The pharmaceutical composition of claim 1, wherein the pH of the composition is about 2.0 to about 8.0. 22. The pharmaceutical composition of claim 1, wherein the pH of the composition is about 4.0 to about 6.0. 23. The pharmaceutical composition of claim 1, wherein the pH of the composition is about 4.5 to about 5.5. 24. The pharmaceutical composition of claim 1, wherein the pH of the composition is about 5.0. 25. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 0.08 μg/mL to about 86 μg/mL. 26. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 0.08 μg/mL to about 43 μg/mL. 27. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 0.08 μg/mL to about 34 μg/mL. 28. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 0.08 μg/mL to about 26 μg/mL. 29. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 0.08 μg/mL to about 17 [μg/mL. 30. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 34 μg/mL. 31. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 30 μg/mL. 32. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 25.6 μg/mL. 33. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 21.4 μg/mL. 34. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 17 μg/mL. 35. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 13 μg/mL. 36. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 10 μg/mL. 37. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 9 μg/mL. 38. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 7 μg/mL. 39. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 4 μg/mL. 40. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 2 μg/mL. 41. The pharmaceutical composition of claim 1, wherein the formoterol free base concentration is about 0.8 μg/mL. 42. The pharmaceutical composition of claim 1, wherein the buffer is citrate buffer; the buffer concentration is about 20 mM; the ionic strength of the composition is about 0.05 to about 0.16; and the pH of the composition is about 5.0. 43. The pharmaceutical composition of claim 1, wherein the buffer is citrate buffer; the buffer concentration is about 5 mM; the ionic strength of the composition is about 0.05 to about 0.16; and the pH of the composition is about 5.0. 44. The pharmaceutical composition of claim 1 that has been nebulized. 45. A nebulized solution, comprising formoterol fumarate in a pharmacologically suitable fluid, wherein formoterol free base concentration is about 0.08 μg/mL to about 128 μg/mL. 46. The nebulized solution of claim 45, wherein formoterol free base concentration is about 17 μg/mL. 47. A kit, comprising: (a) a pharmaceutical composition of claim 1; and (b) a nebulizer. 48. The kit of claim 47, wherein the concentration of formoterol free base is about 17 μg/mL. 49. The kit of claim 47, wherein the pharmaceutical composition comprises (a) formoterol free base at a concentration of about 17 μg/mL; (b) aqueous saline comprising sodium chloride; and (c) citrate buffer at a concentration of about 5 mM; wherein the ionic strength of the composition is about 0.05 to about 0.16; and the pH of the composition is about 5.0. 50. The kit of claim 47, wherein the pharmaceutical composition comprises (a) formoterol free base at a concentration of about 17 μg/mL; (b) aqueous saline comprising sodium chloride; and (c) citrate buffer at a concentration of about 20 mM; wherein the ionic strength of the composition is about 0.05 to about 0.16; and the pH of the composition is about 5.0. 51. A combination, comprising: (a) the pharmaceutical composition of claim 1 formulated for single dosage administration; and (b) a vial. 52. The combination of claim 51, wherein the pharmaceutical composition comprises (a) formoterol free base at a concentration of about 17 μg/mL; (b) aqueous saline comprising sodium chloride; and (c) citrate buffer at a concentration of about 5 mM; wherein the ionic strength of the composition is about 0.05 to about 0.16; and the pH of the composition is about 5.0. 53. The combination of claim 51, wherein the pharmaceutical composition comprises (a) formoterol free base at a concentration of about 17 μg/mL; (b) aqueous saline comprising sodium chloride; and (c) citrate buffer at a concentration of about 20 mM; wherein the ionic strength of the composition is about 0.05 to about 0.16; and the pH of the composition is about 5.0. 54. A method for the treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders, comprising administering an effective amount of the pharmaceutical composition of claim 1 to a subject in need of such treatment. 55. An article of manufacture, comprising packaging material, the composition of claim 1 formulated for single dosage administration, which is useful for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction, and a label that indicates that the composition is used for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction. 56. The method of claim 54, further comprising administering one or more of (a) to (j) as follows: (a) a β2-adrenoreceptor agonist; (b) a dopamine (D2) receptor agonist; (c) an IL-5 inhibitor; (d) an antisense modulator of IL-5; (e) a tryptase inhibitor; (f) a tachykinin receptor antagonist; (g) milrinone or milrinone lactate; (h) a leukotriene receptor antagonist; (i) a 5-lypoxygenase inhibitor; or (j) an anti-IgE antibody; simultaneously with, prior to or subsequent to the formoterol composition. 57. The pharmaceutical composition of claim 1, further comprising one or more of (a) to (j) as follows: (a) a β2-adrenoreceptor agonist; (b) a dopamine (D2) receptor agonist; (c) an IL-5 inhibitor; (d) an antisense modulator of IL-5; (e) a tryptase inhibitor; (f) a tachykinin receptor antagonist; (g) milrinone or milrinone lactate; (h) a leukotriene receptor antagonist; (i) a 5-lypoxygenase inhibitor; or (j) an anti-IgE antibody. 58. The pharmaceutical composition of claim 57 that has been nebulized. 59. The pharmaceutical composition of claim 1 further comprising an anticholinergic agent. 60. The pharmaceutical composition of claim 59, wherein the anticholinergic agent is ipratropium bromide, oxitropium bromide, atropine methyl nitrate, tiotropium bromide or glycopyrronium bromide. 61. The pharmaceutical composition of claim 58, wherein the anticholinergic agent is ipratropium bromide. 62. The pharmaceutical composition of claim 59, wherein the ipratropium bromide is present at a concentration of about 100 μg/mL to about 500 μg/mL. 63. The pharmaceutical composition of claim 59, wherein the ipratropium bromide is present at a concentration of about 150 μg/mL to about 350 μg/mL. 64. The pharmaceutical composition of claim 59, wherein the ipratropium bromide is present at a concentration of about 200 μg/mL to about 300 μg/mL. 65. The pharmaceutical composition of claim 59, wherein the ipratropium bromide is present at a concentration of about 250 μg/mL. 66. The pharmaceutical composition of claim 60, wherein the anticholinergic agent is tiotropium bromide. 67. The pharmaceutical composition of claim 66, wherein the tiotropium bromide is present at a concentration of about 5 μg/mL to about 5 mg/mL. 68. A method for the treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders, comprising administering an effective amount of the pharmaceutical composition of claim 59 to a subject in need of such treatment. 69. An article of manufacture, comprising packaging material, an aqueous composition comprising the composition of claim 59 formulated for single dosage administration, which is useful for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction, and a label that indicates that the composition is used for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction. 70. A method for the treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders, comprising administering a pharmaceutical composition comprising formoterol free base via nebulization to a subject in need of such treatment, wherein the formoterol free base amount in a unit dose is about 0.1 μg to about 250 μg. 71. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 208 μg. 72. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 140 μg. 73. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 68 μg. 74. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 34 μg. 75. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 26 μg. 76. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 21 μg. 77. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 17 μg. 78. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 14 μg. 79. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 9 μg. 80. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 4 μg. 81. The method of claim 70, wherein the amount of formoterol free base in a unit dose is about 1.7 μg. 82. The method of claim 54, wherein the bronchoconstrictive disorder is chronic obstructive pulmonary disease. 83. The method of claim 54, wherein the bronchoconstrictive disorder is asthma. 84. The method of claim 54, wherein the nebulized formoterol solution has a volume of about 0.1 mL to about 3 mL. 85. The method of claim 54, wherein the nebulized formoterol solution has a volume of about 2 mL. 86. The method of claim 54, wherein the nebulized formoterol solution has a volume of about 1 mL. 87. The method of claim 54, wherein the nebulized formoterol solution has a volume of about 0.5 mL. 88. The pharmaceutical composition of claim 1, wherein the formoterol is formoterol fumarate. 89. The pharmaceutical composition of claim 1, wherein the formoterol is formoterol fumarate dihydrate. 90. The pharmaceutical composition of claim 1, wherein the formoterol is (R,R)-formoterol. 91. The pharmaceutical composition of claim 1, wherein the formoterol is (S,S)-formoterol. 92. The combination of claim 51 further comprising a nebulizer. 93. A kit comprising the combination of claim 51, optionally containing instructions for use. 94. The method of claim 56, wherein the bronchoconstrictive disorder is chronic obstructive pulmonary disease. 95. The method of claim 56, wherein the bronchoconstrictive disorder is asthma. 96. The method of claim 56, wherein the nebulized formoterol solution has a volume of about 0.1 mL to about 3 mL. 97. The method of claim 56, wherein the nebulized formoterol solution has a volume of about 2 mL. 98. The method of claim 56, wherein the nebulized formoterol solution has a volume of about 1 mL. 99. The method of claim 56, wherein the nebulized formoterol solution has a volume of about 0.5 mL. 100. The method of claim 68, wherein the bronchoconstrictive disorder is chronic obstructive pulmonary disease. 101. The method of claim 68, wherein the bronchoconstrictive disorder is asthma. 102. The method of claim 68, wherein the nebulized formoterol solution has a volume of about 0.1 mL to about 3 mL. 103. The method of claim 68, wherein the nebulized formoterol solution has a volume of about 2 mL. 104. The method of claim 68, wherein the nebulized formoterol solution has a volume of about 1 mL. 105. The method of claim 68, wherein the nebulized formoterol solution has a volume of about 0.5 mL. 106. The method of claim 70, wherein the bronchoconstrictive disorder is chronic obstructive pulmonary disease. 107. The method of claim 70, wherein the bronchoconstrictive disorder is asthma. 108. The method of claim 70, wherein the nebulized formoterol solution has a volume of about 0.1 mL to about 3 mL. 109. The method of claim 70, wherein the nebulized formoterol solution has a volume of about 2 mL. 110. The method of claim 70, wherein the nebulized formoterol solution has a volume of about 1 mL. 111. The method of claim 70, wherein the nebulized formoterol solution has a volume of about 0.5 mL. | RELATED APPLICATIONS This application claims priority under 35 U.S.C. §1 19(e) to U.S. Provisional Patent Application No. 60/486,386, filed Jul. 10, 2003, entitled “BRONCHODILATING β-AGONIST COMPOSITIONS AND METHODS.” The disclosure of the above-referenced application is incorporated by reference herein in its entirety. FIELD Compositions and methods are provided relating to treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders. In particular, the compositions and methods herein include formoterol, and/or derivatives thereof. The compositions are propellant-free, sterile unit dose or multidose inhalation solutions intended for administration via nebulization. BACKGROUND Bronchoconstrictive disorders affect millions worldwide. Such disorders include asthma (including bronchial asthma, allergic asthma and intrinsic asthma, e.g., late asthma and airway hyper-responsiveness), chronic bronchitis and other chronic obstructive pulmonary diseases. Compounds having β2-adrenoreceptor agonist activity have been developed to treat these conditions. Such compounds include, but are not limited to, Albuterol (α1-(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); Bambuterol (dimethylcarbamic acid 5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-phenylene ester); Bitolterol (4-methylbenzoic acid 4-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,2-phenylene ester); Broxaterol (3-bromo-α-(((1,1-dimethylethyl)amino)methyl)-5-isoxazolemethanol); Isoproterenol (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Trimetoquinol (1,2,3,4-tetrahydro-1-((3,4,5-trimethoxyphenyl)methyl)-6,7-isoquinolinediol); Clenbuterol (4-amino-3,5-dichloro-α-(((1,1-diemthylethyl)amino)methyl)benzenemethanol); Fenoterol (5-(1-hydroxy-2-((2-(4-hydroxyphenyl)-1-methylethyl)amino)ethyl)-1,3-benzenediol); Formoterol (2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methyl-ethyl)amino)ethyl)formanilide); (R,R)-Formoterol; Desformoterol ((R,R) or (S,S)-3-amino-4-hydroxy-α-(((2-(4-methoxyphenyl)-1-methylethyl)amino)methyl)benzene-methanol); Hexoprenaline (4,4′-(1,6-hexanediyl)-bis(imino(1-hydroxy-2,1-ethane-diyl)))bis-1,2-benzenediol); Isoetharine (4-(1-hydroxy-2-((1-methylethyl)amino)butyl)-1,2-benzenediol); Isoprenaline (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Metaproterenol (5-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,3-benzenediol); Picumeterol (4-amino-3,5-dichloro-α-(((6-(2-(2-pyridinyl)ethoxy)hexyl)-amino)methyl)benzenemethanol); Pirbuterol (α6-(((1,1-dimethylethyl)amino)methyl)-3-hydroxy-2,6-pyridinemethanol); Procaterol (((R*,S*)-(±)-8-hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-2(1H)-quinolinone); Reproterol ((7-(3-((2-(3,5-dihydroxyphenyl)-2-hydroxyethyl)amino)propyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione); Rimiterol (4-(hydroxy-2-piperidinylmethyl)-1,2-benzenediol); Salbutamol ((±)-α1-(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); (R)-Salbutamol; Salmeterol ((±)-4-hydroxy-α1-(((6-(4-phenylbutoxy)hexyl)amino)methyl)-1,3-benzenedimethanol); (R)-Salmeterol; Terbutaline (5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-benzenediol); Tulobuterol (2-chloro-α-(((1,1-dimethyl-ethyl)amino)methyl)benzenemethanol); and TA-2005 (8-hydroxy-5-((1R)-1-hydroxy-2-(N-((1R)-2-(4-methoxyphenyl)-1-methylethyl)amino)ethyl)carbostyril hydrochloride). These compounds are typically formulated for inhalation therapy. Aqueous or liquid formulations are preferred over solid formulations. Powdered formulations are more difficult to administer, particularly to the young and elderly who are most often the patients in need of such therapy. Compounds, such as formoterol are not adequately stable in aqueous solutions to be formulated as liquids. Hence there is a need for formulations of compounds, such as formoterol, in a form that can be conveniently administered and that are stable for extended periods of time. SUMMARY Compositions and methods for treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders are provided. The compositions provided herein are stable solutions of a bronchodilating agent, or a derivative thereof, in a pharmacologically suitable fluid that contains water, that are stable during long term storage. The compositions are suitable for direct administration to a subject in need thereof. Pharmacologically suitable fluids include, but are not limited to, polar fluids, including protic fluids. In certain embodiments herein, the compositions are aqueous solutions. The compositions provided herein possess an estimated shelf-life of greater than 1, 2 or 3 months usage time at 25° C. and greater than or equal to 1, 2 or 3 years storage time at 5° C. In certain of these embodiments, using Arrhenius kinetics, >80% or >85% or >90% or >95% estimated bronchodilating agent remains after such storage. These compositions are particularly useful for administration via nebulization. In certain embodiments herein, the subject is a mammal. In other embodiments, the subject is a human. The compositions provided herein are formulated to remain stable over a relatively long period of time. For example, the compositions provided herein are stored between −15° C. and 25° C., or between 2° C. and 8° C., and remain stable for the desired time. In one embodiment, the compositions are stored at 5° C. In other embodiment, the compositions are stored at 25° C. Among the bronchodilating agents for use herein are Albuterol (α1-(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); Bambuterol (dimethylcarbamic acid 5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-phenylene ester); Bitolterol (4-methylbenzoic acid 4-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,2-phenylene ester); Broxaterol (3-bromo-α-(((1,1-dimethylethyl)amino)-methyl)-5-isoxazolemethanol); Isoproterenol (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Trimetoquinol (1,2,3,4-tetrahydro-1-((3,4,5-trimethoxyphenyl)methyl)-6,7-isoquinolinediol); Clenbuterol (4-amino-3,5-dichloro-α-(((1,1-diemthylethyl)amino)methyl)benzenemethanol); Fenoterol (5-(1-hydroxy-2-((2-(4-hydroxyphenyl)-1-methylethyl)amino)ethyl)-1,3-benzenediol); Formoterol (2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)-formanilide); (R,R)-Formoterol; (S,S)-Formoterol; Desformoterol ((R,R) or (S,S)-3-amino-4-hydroxy-α-(((2-(4-methoxyphenyl)-1-methylethyl)amino)methyl)benzene-methanol); Hexoprenaline (4,4′-(1,6-hexanediyl)-bis(imino(1-hydroxy-2,1-ethane-diyl)))bis-1,2-benzenediol); Isoetharine (4-(1-hydroxy-2-((1-methylethyl)amino)butyl)-1,2-benzenediol); Isoprenaline (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Metaproterenol (5-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,3-benzenediol); Picumeterol (4-amino-3,5-dichloro-α-(((6-(2-(2-pyridinyl)ethoxy)hexyl)-amino)methyl)benzenemethanol); Pirbuterol (α6-(((1,1-dimethylethyl)amino)methyl)-3-hydroxy-2,6-pyridinemethanol); Procaterol (((R*,S*)-(±)-8-hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-2(1H)-quinolinone); Reproterol ((7-(3-((2-(3,5-dihydroxyphenyl)-2-hydroxyethyl)amino)propyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione); Rimiterol (4-(hydroxy-2-piperidinylmethyl)-1,2-benzenediol); Salbutamol ((±)-α1-(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); (R)-Salbutamol; Salmeterol ((±)-4-hydroxy-α1-(((6-(4-phenylbutoxy)hexyl)amino)methyl)-1,3-benzenedimethanol); (R)-Salmeterol; Terbutaline (5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-benzenediol); Tulobuterol (2-chloro-α-(((1,1-dimethyl-ethyl)amino)methyl)benzenemethanol); and TA-2005 (8-hydroxy-5-((1R)-1-hydroxy-2-(N-((1R)-2-(4-methoxyphenyl)-1-methylethyl)amino)ethyl)carbostyril hydrochloride). Of particular interest herein is formoterol, having the formula: Formoterol for use in the compositions and methods provided herein includes 2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide; or a stereoisomer thereof; and also includes the single enantiomers 2-hydroxy-5-((1S)-1-hydroxy-2-(((1S)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide and 2-hydroxy-5-((1R)-1-hydroxy-2-(((1R)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide. In certain embodiments, the compositions are administered via nebulization. Administration of a nebulized aerosol is preferred over the use of dry powders for inhalation in certain subject populations, including pediatric and geriatric groups. In one embodiment, the compositions for use in the methods provided herein contain a pharmaceutically acceptable derivative of formoterol. In another embodiment, the compositions for use in the methods provided herein contain a pharmaceutically acceptable salt of formoterol. Pharmaceutically acceptable salts include, but are not limited to, salts of mineral acids, such as but not limited to hydrochlorides and sulfates; and salts of organic acids, such as but not limited to acetates, lactates, malates, tartrates, citrates, ascorbates, succinates, butyrates, valerates and fumarates. In one embodiment, the compositions for use in the methods provided herein contain formoterol fumarate or formoterol fumarate dihydrate. In another embodiment, the compositions for use in the methods provided herein contain formoterol tartrate. Also provided herein are combinations containing a composition provided herein and a nebulizer. The combinations can be packaged as kits, which optionally contain other components, including instructions for use of the nebulizer. Any nebulizer is contemplated for use in the kits and methods provided herein. In particular, the nebulizers for use herein nebulize liquid formulations, including the compositions provided herein, containing no propellant. The nebulizer may produce the nebulized mist by any method known to those of skill in the art, including, but not limited to, compressed air, ultrasonic waves, or vibration. The nebulizer may further have an internal baffle. The internal baffle, together with the housing of the nebulizer, selectively removes large droplets from the mist by impaction and allows the droplets to return to the reservoir. The fine aerosol droplets thus produced are entrained into the lung by the inhaling air/oxygen. Methods for the treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders, including, but not limited to, asthma, including, but not limited to, bronchial asthma, allergic asthma and intrinsic asthma, e.g., late asthma and airway hyper-responsiveness; chronic bronchitis; and other chronic obstructive pulmonary diseases are provided. The methods involve administering an effective amount of a pharmaceutical composition provided herein to a subject in need of such treatment. Articles of manufacture, containing packaging material, a composition provided herein, which is useful for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction, and a label that indicates that the composition is used for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction, are also provided. DETAILED DESCRIPTION Definitions Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this invention belongs. All patents, applications, published applications and other publications are incorporated by reference in their entirety. In the event that there are a plurality of definitions for a term herein, those in this section prevail unless stated otherwise. As used herein, formoterol refers to 2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide; or a stereoisomer thereof. The term formoterol also refers to the single enantiomers 2-hydroxy-5-((1S)-1-hydroxy-2-(((1S)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide ((S,S)-formoterol) and 2-hydroxy-5-((1R)-1-hydroxy-2-(((1R)-2-(p-methoxyphenyl)-1-methylethyl)amino)-ethyl)formanilide ((R,R)-formoterol). As used herein, formoterol fumarate refers to a salt of formoterol having the formula (formoterol)·½ fumarate. As used herein, formoterol free base refers to the neutral, anhydrous form of formoterol. Thus, a recitation that a composition contains, e.g., 20 μg/mL of formoterol free base means that the composition contains 20 μg/mL of neutral, anhydrous formoterol. Such compositions may be prepared using a derivative of formoterol. As used herein, an aerosol is liquid or particulate matter dispersed in air. Aerosols include dispersions of liquids, including aqueous and other solutions, and solids, including powders, in air. As used herein, a nebulized solution refers to a solution that is dispersed in air to form an aerosol. Thus, a nebulized solution is a particular form of an aerosol. As used herein, a nebulizer is an instrument that is capable of generating very fine liquid droplets for inhalation into the lung. Within this instrument, the nebulizing liquid or solution is atomized into a mist of droplets with a broad size distribution by methods known to those of skill in the art, including, but not limited to, compressed air, ultrasonic waves, or a vibrating orifice. Nebulizers may further contain, e.g., a baffle which, along with the housing of the instrument, selectively removes large droplets from the mist by impaction. Thus, the mist inhaled into the lung contains fine aerosol droplets. As used herein, a pharmacologically suitable fluid is a solvent suitable for pharmaceutical use which is not a liquified propellant gas. Exemplary pharmacologically suitable fluids include polar fluids, including protic fluids such as water. As used herein, a kit refers to one or more items, including, but not limited to, compounds, compositions, combinations, instruments and devices, suitably packaged for use. Kits provided herein optionally contain instructions for use. As used herein, a combination refers to any association between two or among more items. As used herein, fluid refers to any composition that can flow. Fluids thus encompass compositions that are in the form of semi-solids, pastes, solutions, aqueous mixtures, gels, lotions, creams and other such compositions. As used herein, a mixture is a mutual incorporation of two or more substances, without chemical union, the physical characteristics of each of the components being retained. As used herein, the stability of a composition provided herein refers to the length of time at a given temperature that is greater than 80%, 85%, 90% or 95% of the initial amount of active ingredient, e.g., formoterol, is present in the composition. Thus, for example, a composition that is stable for 30 days at 25° C. would have greater than 80%, 85%, 90% or 95% of the initial amount of active ingredient present in the composition at 30 days following storage at 25° C. As used herein, pharmaceutically acceptable derivatives of a compound include salts, esters, enol ethers, enol esters, acids, bases, solvates, hydrates or prodrugs thereof. Such derivatives may be readily prepared by those of skill in this art using known methods for such derivatization. The compounds produced may be administered to animals or humans without substantial toxic effects and either are pharmaceutically active or are prodrugs. Pharmaceutically acceptable salts include, but are not limited to, amine salts, such as but not limited to N,N′-dibenzylethylenediamine, chloroprocaine, choline, ammonia, diethanolamine and other hydroxyalkylamines, ethylenediamine, N-methylglucamine, procaine, N-benzylphenethylamine, 1-para-chlorobenzyl-2-pyrrolidin-1′-ylmethylbenzimidazole, diethylamine and other alkylamines, piperazine and tris(hydroxymethyl)aminomethane; alkali metal salts, such as but not limited to lithium, potassium and sodium; alkali earth metal salts, such as but not limited to barium, calcium and magnesium; transition metal salts, such as but not limited to zinc; and other metal salts, such as but not limited to sodium hydrogen phosphate and disodium phosphate; and also including, but not limited to, salts of mineral acids, such as but not limited to hydrochlorides and sulfates; and salts of organic acids, such as but not limited to acetates, lactates, malates, tartrates, citrates, ascorbates, succinates, butyrates, valerates and fumarates. Pharmaceutically acceptable esters include, but are not limited to, alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, cycloalkyl and heterocyclyl esters of acidic groups, including, but not limited to, carboxylic acids, phosphoric acids, phosphinic acids, sulfonic acids, sulfinic acids and boronic acids. Pharmaceutically acceptable enol ethers include, but are not limited to, derivatives of formula C═C(OR) where R is hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, cycloalkyl and heterocyclyl. Pharmaceutically acceptable enol esters include, but are not limited to, derivatives of formula C═C(OC(O)R) where R is hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, cycloalkyl and heterocyclyl. Pharmaceutically acceptable solvates and hydrates are complexes of a compound with one or more solvent or water molecule, in certain embodiments 1 to about 100, in other embodiments 1 to about 10, in further embodiments one to about 2, 3 or 4, solvent or water molecules. Formoterol salts and hydrates are used in certain embodiments herein. As used herein, treatment means any manner in which one or more of the symptoms of a condition, disorder or disease are ameliorated or otherwise beneficially altered. Treatment also encompasses any pharmaceutical use of the compositions herein, such as use for treating cancer. As used herein, amelioration of the symptoms of a particular disorder by administration of a particular pharmaceutical composition refers to any lessening, whether permanent or temporary, lasting or transient that can be attributed to or associated with administration of the composition. As used herein, a prodrug is a compound that, upon in vivo administration, is metabolized or otherwise converted to the biologically, pharmaceutically or therapeutically active form of the compound. To produce a prodrug, the pharmaceutically active compound is modified such that the active compound will be regenerated by metabolic processes. The prodrug may be designed to alter the metabolic stability or the transport characteristics of a drug, to mask side effects or toxicity, to improve the flavor of a drug or to alter other characteristics or properties of a drug. By virtue of knowledge of pharmacodynamic processes and drug metabolism in vivo, those of skill in this art, once a pharmaceutically active compound is known, can design prodrugs of the compound (see, e.g., Nogrady (1985) Medicinal Chemistry A Biochemical Approach, Oxford University Press, New York, pages 388-392). It is to be understood that the compounds for use in the compositions and methods provided herein may contain chiral centers. Such chiral centers may be of either the (R) or (S) configuration, or may be a mixture thereof. Thus, the compounds for use in the compositions provided herein may be enantiomerically pure, or be stereoisomeric or diastereomeric mixtures. It is to be understood that the chiral centers of the compounds provided herein may undergo epimerization in vivo. Thus, one of skill in the art will recognize that administration of a compound in its (R) form is equivalent, for compounds that undergo epimerization in vivo, to administration of the compound in its (S) form. As used herein, bronchoconstriction refers to a reduction in the caliber of a bronchus or bronchi. As used herein, undesired and/or uncontrolled bronchoconstriction refers to bronchoconstriction that results in or from a pathological symptom or condition. Pathological conditions include, but are not limited to, asthma and chronic obstructive pulmonary disease (COPD). Pathological symptoms include, but are not limited to, asthma and COPD. As used herein, the statement that a composition is stable during “long term storage” means that the composition is suitable for administration to a subject in need thereof when it has an estimated shelf-life of greater than 1, 2 or 3 months usage time at 25° C. and greater than or equal to 1, 2 or 3 years storage time at 5° C. In certain embodiments herein, using Arrhenius kinetics, >80% or >85% or >90% or >95% estimated bronchodilating agent remains after such storage. A. Formoterol Formoterol (2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide) is derived from adrenaline and, as noted above, is used as a β2-stimulator in inhalation therapy of respiratory diseases, particularly for the treatment of bronchial asthma. It has been reported that in patients with reversible obstructive respiratory diseases, formoterol has a bronchodilatory effect. This effect has a relatively rapid onset (approximately 1-3 minutes) and a relatively long duration (greater than 12 hours). Formoterol inhibits the release of leukotrienes and other messenger substances involved with inflammation, such as histamines. In addition, formoterol may bring about a hyperglycaemic activity. To date, formoterol has been formulated as a dry powder and administered via devices such as the TURBUHALER® and the AEROLIZER®. See, e.g., Seberova et al. (2000) Respir. Med. 94(6):607-611; Lotvall et al. (1999) Can. Respir. J. 6(5):412-416; Campbell et al. (1999) Respir. Med. 93(4):236-244; Nightingale et al. (1999) Am. J. Respir. Crit. Care Med. 159(6):1786-1790; Lecaillon et al. (1999) Eur. J. Clin. Pharmacol. 55(2):131-138; Bartow et al. (1998) Drugs 55(2):303-322; Ekstrom et al. (1998) Respir. Med. 92(8):1040-1045; Ringdal et al. (1998) Respir. Med. 92(8):1017-1021; Totterman et al. (1998) Eur. Respir. J. 12(3):573-579; Palmqvist et al. (1997) Eur. Respir. J. 10(11):2484-2489; Nielsen et al. (1997) Eur. Respir. J. 10(9):2105-2109; Ullman et al. (1996) Allergy 51(10):745-748; Selroos et al. (1996) Clin. Immunother. 6:273-299; and Schreurs et al. (1996) Eur. Respir. J. 9(8):1678-1683. Formoterol is also available as a tablet and a dry syrup in certain areas of the world (e.g., ATOCK®, marcketed by Yamanouchi Pharmaceutical Co. Ltd., Japan). Formoterol formulations are also available in other areas (e.g., Europe and U.S.) for propellant-based metered dose inhalers and dry powder inhalers (e.g., TURBUHALER®, AEROLIZER® AND FORADIL AEROLIZER®). None of these formulations are water based. Sterile, stable, aqueous based inhalation solutions of formoterol for nebulization are not available, nor have they been reported. In the treatment of bronchoconstrictive diseases, sufficient amount of the inhaled drug should reach their local site of action in order to be efficacious. It is known that different delivery methods and delivery devices have different deposition characterstics. Consequently, under optimal inhalation conditions, doses from different delivery methods and delivery devices result in different delivered doses and different amounts deposited at the active site. The actual dose reaching the active site also depends upon the amount of drug particles included in the delivered dose and the inhalation characterstics of the patient. No correlation between the amount of drug administered by dry powder inhalers (DPIs) or metered dose inhalers (MDIs) and the actual amount that gets deposited at the active site has been established so far. Nor has a correlation been established between DPI or MDI dosages and nebulization dosages. Compositions containing formoterol in combination with other active ingredients have been disclosed. See, e.g., U.S. Pat. Nos. 6,004,537, 5,972,919 and 5,674,860 (formoterol and budenoside), U.S. Pat. Nos. 5,668,110, 5,683,983, 5,677,280 and 5,654,276 (formoterol and IL-5 inhibitors), U.S. Pat. No. 6,136,603 (formoterol and antisense modulators of IL-5), U.S. Pat. No. 5,602,110 (formoterol and millrinone), U.S. Pat. No. 5,525,623 (formoterol and a tryptase inhibitor), U.S. Pat. Nos. 5,691,336, 5,877,191, 5,929,094, 5,750,549 and 5,780,467 (formoterol and a tachykinin receptor antagonist); and International Patent Application Publication Nos. WO 99/00134 (formoterol and rofleponide) and WO 99/36095 (formoterol and a dopamine D2 receptor agonist). Other compositions containing formoterol have been disclosed in U.S. Pat. Nos. 5,677,809, 6,126,919, 5,733,526, 6,071,971, 6,068,833, 5,795,564, 6,040,344, 6,041,777, 5,874,481, 5,965,622 and 6,161,536. U.S. Pat. No. 6,150,418 discloses a “liquid active substance concentrate” containing formoterol in the form of its free base or in the form of one of the pharmacologically acceptable salts or addition products (adducts) thereof as active substance. This “liquid active substance concentrate” is reported to be a concentrated (i.e., greater than 10 mg/mL, preferably 75 to 500 mg/mL) solution or suspension that is stable for a period of several months possibly up to several years without any deterioration in the pharmaceutical quality. This patent teaches that it is the high concentration that allows for the stability of the concentrate. The “liquid active substance concentrate” is not suitable for direct administration to a patient. U.S. Pat. No. 6,040,344 discloses an aqueous aerosol formulation of formoterol tartrate for use in a nebulizer. This patent states that the formulation disclosed therein is not attractive for long term storage. B. Compositions for Use in Treatment, Prevention, or Amelioration of One or More Symptoms of Bronchoconstrictive Disorders Pharmaceutical compositions containing a β2-adrenoreceptor agonist for administration via nebulization are provided. The compositions are sterile filtered and filled in vials, including unit dose vials providing sterile unit dose formulations which are used in a nebulizer and suitably nebulized. Each unit dose vial is sterile and is suitably nebulized without contaminating other vials or the next dose. The unit dose vials are formed in a form-fill-seal machine or by any other suitable method known to those of skill in the art. The vials may be made of plastic materials that are suitably used in these processes. For example, plastic materials for preparing the unit dose vials include, but are not limited to, low density polyethylene, high density polyethylene, polypropylene and polyesters. In one embodiment, the plastic material is low density polyethylene. In one embodiment, the β2-adrenoreceptor agonist is formoterol, or a pharmaceutically acceptable derivative thereof. In other embodiments, the formoterol for use in the compositions provided herein is formoterol fumarate. Formoterol refers to 2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide; or a stereoisomer thereof. The term formoterol also refers herein to the single enantiomers 2-hydroxy-5-((1S)-1-hydroxy-2-(((1S)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide and 2-hydroxy-5-((1R)-1-hydroxy-2-(((1R)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide. In certain embodiments, the compositions contain formoterol fumarate at a concentration of about 0.1 μg/mL up to about 150 μg/mL, or 0.1 μg/mL up to 150 μg/mL. In further embodiments, the compositions contain formoterol fumarate at a concentration of about 0.1 μg/mL up to about 100 μg/mL, or 0.1 μg/mL up to 100 μg/mL. The formoterol fumarate is formulated, in certain compositions provided herein, at a concentration of about 0.1 μg/mL up to 50 μg/mL, or 0.1 μg/mL up to 50 μg/mL. In further embodiments, the compositions contain formoterol fumarate at a concentration of about 0.1 μg/mL up to about 40 μg/mL, or 0.1 μg/mL up to 40 μg/mL. In further embodiments, the compositions contain formoterol fumarate at a concentration of about 0.1 μg/mL up to about 20 μg/mL, or 0.1 μg/mL up to 20 μg/mL. The formoterol fumarate is formulated, in other compositions provided herein, at a concentration of about 40 μg/mL, or 40 μg/mL. In further embodiments, the compositions contain formoterol fumarate at a concentration of about 35 μg/mL, or 35 μg/mL. In other embodiments, the compositions contain formoterol fumarate at a concentration of about 30 μg/mL, or 30 μg/mL. In other embodiments, the compositions contain formoterol fumarate at a concentration of about 25 μg/mL, or 25 μg/mL. In further embodiments, the compositions contain formoterol fumarate at a concentration of about 20 μg/mL, or 20 μg/mL. In another embodiment, the compositions contain formoterol fumarate at a concentration of about 15 μg/mL, or 15 μg/mL. In another embodiment, the compositions contain formoterol fumarate at a concentration of about 12 μg/mL, or 12 μg/mL. In another embodiment, the compositions contain formoterol fumarate at a concentration of about 10 μg/mL, or 10 μg/mL. In another embodiment, the compositions contain formoterol fumarate at a concentration of about 8 μg/mL, or 8 μg/mL. In another embodiment, the compositions contain formoterol fumarate at a concentration of about 5 μg/mL, or 5 μg/mL. In another embodiment, the compositions contain formoterol fumarate at a concentration of about 2.5 μg/mL, or 2.5 μg/mL. In another embodiment, the compositions contain formoterol fumarate at a concentration of about 1 μg/mL, or 1 μg/mL. In certain embodiments, the compositions contain formoterol free base at a concentration of about 0.08 μg/mL up to about 128 μg/mL, or 0.08 μg/mL up to 128 μg/mL. In further embodiments, the compositions contain formoterol free base at a concentration of about 0.08 μg/mL up to about 86 μg/mL, or 0.08 μg/mL up to 86 μg/mL. The formoterol free base is formulated, in certain compositions provided herein, at a concentration of about 0.08 μg/mL up to 43 μg/mL, or 0.08 μg/mL up to 43 μg/mL. In further embodiments, the compositions contain formoterol free base at a concentration of about 0.08 μg/mL up to about 34 μg/mL, or 0.08 μg/mL up to 34 μg/mL. In further embodiments, the compositions contain formoterol free base at a concentration of about 0.08 μg/mL up to about 26 μg/mL, or 0.08 μg/mL up to 26 μg/mL. The formoterol free base is formulated, in other compositions provided herein, at a concentration of about 0.08 μg/mL up to about 17 μg/mL, or 0.08 μg/mL up to 17 μg/mL. In further embodiments, the compositions contain formoterol free base at a concentration of about 34 μg/mL, or 34 [μg/mL. In further embodiments, the compositions contain formoterol free base at a concentration of about 30 μg/mL, or 30 μg/mL. In other embodiments, the compositions contain formoterol free base at a concentration of about 25.6 μg/mL, or 25.6 μg/mL. In further embodiments, the compositions contain formoterol free base at a concentration of about 21.4 μg/mL, or 21.4 μg/mL. In further embodiments, the compositions contain formoterol free base at a concentration of about 17 μg/mL, or 17 μg/mL. In another embodiment, the compositions contain formoterol free base at a concentration of about 13 μg/mL, or 13 μg/mL. In another embodiment, the compositions contain formoterol free base at a concentration of about. 10 μg/mL, or 10 μg/mL. In another embodiment, the compositions contain formoterol free base at a concentration of about 9 μg/mL, or 9 μg/mL. In another embodiment, the compositions contain formoterol free base at a concentration of about 7 μg/mL, or 7 μg/mL. In another embodiment, the compositions contain formoterol free base at a concentration of about 4 μg/mL, or 4 μg/mL. In another embodiment, the compositions contain formoterol free base at a concentration of about 2 μg/mL, or 2 μg/mL. In another embodiment, the compositions contain formoterol free base at a concentration of about 0.8 μg/mL, or 0.8 μg/mL. The volume of formoterol inhalation solution nebulized depends on the nebulizer used. In certain embodiments, the volume is from about 0.1 mL up to about 3 mL, or 0.1 mL up to 3 mL. In other embodiments, the volume is about 2 mL, or 2 mL. In other embodiments, the volume is about 1 mL, or 1 mL. In other embodiments, the volume is about 0.5 mL, or 0.5 mL. The compositions containing the β2-adrenoreceptor agonist, including formoterol, are formulated with a pharmacologically suitable fluid. Pharmacologically suitable fluids include, but are not limited to, polar solvents, including, but not limited to, compounds that contain hydroxyl groups or other polar groups. Such solvents include, but are not limited to, water or alcohols, such as ethanol, isopropanol, and glycols including propylene glycol, polyethylene glycol, polypropylene glycol, glycol ether, glycerol and polyoxyethylene alcohols. Polar solvents also include protic solvents, including, but not limited to, water, aqueous saline solutions with one or more pharmaceutically acceptable salt(s), alcohols, glycols or a mixture thereof. For a saline solution as the solvent or as a component thereof, particularly suitable salts are those which display no or only negligible pharmacological activity after administration. In the embodiments herein, the compositions have a pH of about 2.0 to about 8.0, or 2.0 to 8.0. In other embodiments, the compositions have a pH of about 4.0 to about 6.0, or 4.0 to 6.0. In other embodiments, the pH is about 4.5 to about 5.5, or 4.5 to 5.5. In certain of the above embodiments, the compositions are formulated at a pH of about 4, 4.4 or 4.6 up to about 5.5, 5.7 or 6; or 4, 4.4 or 4.6 up to 5.5, 5.7 or 6. In other embodiments, the pH is about 5.0, or 5.0. It has been found that the rate constant for decomposition of an aqueous solution of formoterol is dependent on pH. The rate constant (kobs) at 60° C. at a pH of 3, 4, 5 and 7 is approximately 0.62, 0.11, 0.044 and 0.55 day−1, respectively. Therefore, the decomposition of formoterol in aqueous solution at 60° C. at a buffer concentration of 5 mM and an ionic strength of 0.05 is slowest at a pH of about 5.0, or 5.0. The solubility of formoterol in aqueous solution has been found to be dependent on pH. Thus, at a pH of between about 5 and about 7, the aqueous solubility of formoterol at ambient temperature is approximately 2.2 mg/mL. At a pH of about 4, the aqueous solubility of formoterol at ambient temperature is approximately 3 mg/mL, while at a pH of about 3, the aqueous solubility of formoterol at ambient temperature is about 4.8 mg/mL. The solubility of formoterol in pure water, for example, high performance liquid chromatography (HPLC) water, at ambient temperature is approximately 2 mg/mL. In other of the above embodiments, the compositions further contain a buffer, including, but not limited to, citric acid/phosphate, acetate, barbital, borate, Britton-Robinson, cacodylate, citrate, collidine, formate, maleate, McIlvaine, phFosphate, Prideaux-Ward, succinate, citrate-phosphate-borate (Teorell-Stanhagen), veronal acetate, MES (2-(N-morpholino)ethanesulfonic acid), BIS-TRIS (bis(2-hydroxyethyl)iminotris-(hydroxymethyl)methane), ADA (N-(2-acetamido)-2-iminodiacetic acid), ACES (N-(carbamoylmethyl)-2-aminoethanesulfonic acid), PIPES (piperazine-N,N′-bis(2-ethanesulfonic acid)), MOPSO (3-(N-morpholino)-2-hydroxypropanesulfonic acid), BISTRIS PROPANE (1,3-bis(tris(hydroxymethyl)methylamino)propane), BES (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), MOPS (3-(N-morpholino)propanesulfonic acid), TES (N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid), HEPES (N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid), DIPSO (3-(N,N-bis(2-hydroxyethyl)amino)-2-hydroxypropanesulfonic acid), MOBS (4-(N-morpholino)-butanesulfonic acid), TAPSO (3-(N-tris(hydroxymethyl)methylamino)-2-hydroxypropanesulfonic acid), TRIZMA® (tris(hydroxymethylaminomethane), HEPPSO (N-(2-hydroxyethyl)piperazine-N′-(2-hydroxypropanesulfonic acid), POPSO (piperazine-N,N′-bis(2-hydroxypropanesulfonic acid)), TEA (triethanolamine), EPPS (N-(2-hydroxyethyl)piperazine-N′-(3-propanesulfonic acid), TRICINE (N-tris(hydroxy-methyl)methylglycine), GLY-GLY (glycylglycine), BICINE (N,N-bis(2-hydroxyethyl)glycine), HEPBS (N-(2-hydroxyethyl)piperazine-N′-(4-butanesulfonic acid)), TAPS (N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid), AMPD (2-amino-2-methyl-1,3-propanediol), and/or any other buffers known to those of skill in the art. In one embodiment, the buffer is citric acid/phosphate buffer, acetate buffer, citrate buffer or phosphate buffer. In another embodiment, the buffer is a citrate buffer (citric acid/sodium citrate). The buffer concentration has been found to affect the stability of the composition. Buffer concentrations for use include from about 0 or 0.01 mM to about 150 mM, or 0 or 0.01 mM to 150 mM. In another embodiment, the buffer concentration is about 1 mM to about 20 mM, or 1 mM to 20 mM. In one embodiment, the buffer concentration is about 5 mM, or 5mM. In other embodiments, the buffer concentration is about 1 mM to about 50 mM, or 1 mM to 50 mM. In one embodiment, the buffer concentration is about 20 mM, or 20mM. The kinetic-pH profile of formoterol is dependent on buffer concentration. At low and approximately neutral conditions, increasing the buffer concentration from 5 mM to 20 mM increased the rate constant of decomposition significantly. However, no noticeable differences in rate constant were observed in the pH region of about 4.5 to about 5.5, with increasing buffer concentration from 5 mM to 20 mM. The particular buffer and buffer concentration of a given composition for long term storage provided herein may be determined empirically using standard stability assays well known to those of skill in the art (see, e.g., the Examples). The ionic strength of the compositions provided herein also has been found to affect the stability of the composition. Ionic strengths of the compositions provided herein are from about 0 to about 0.4, or 0 to 0.4. In another embodiment, the ionic strgnth of the compositions provided is about 0.05 to about 0.16, or 0.05 to 0.16. Compositions having a lower ionic strength exhibit improved stability over formulations having higher ionic strength. The rate constant of decomposition was essentially the same at ionic strength 0.05 to 0.1, but increased to some extent at ionic strength of 0.2. The particular ionic strength of a given composition for long term storage provided herein may be determined empirically using standard stability assays well known to those of skill in the art (see, e.g., the Examples). In embodiments where the pharamacologically suitable fluid is a saline solution, tonicity adjusting agents may be added to provide the desired ionic strength. Tonicity adjusting agents for use herein include those which display no or only negligible pharmacological activity after administration. Both inorganic and organic tonicity adjusting agents may be used in the compositions provided herein. Tonicity adjusting agents include, but are not limited to, ammonium carbonate, ammonium chloride, anmmonium lactate, ammonium nitrate, ammonium phosphate, ammonium sulfate, ascorbic acid, bismuth sodium tartrate, boric acid, calcium chloride, calcium disodium edetate, calcium gluconate, calcium lactate, citric acid, dextrose, diethanolamine, dimethylsulfoxide, edetate disodium, edetate trisodium monohydrate, fluorescein sodium, fructose, galactose, glycerin, lactic acid, lactose, magnesium chloride, magnesium sulfate, mannitol, polyethylene glycol, potassium acetate, potassium chlorate, potassium chloride, potassium iodide, potassium nitrate, potassium phosphate, potassium sulfate, propylene glycol, silver nitrate, sodium acetate, sodium bicarbonate, sodium biphosphate, sodium bisulfite, sodium borate, sodium bromide, sodium cacodylate, sodium carbonate, sodium chloride, sodium citrate, sodium iodide, sodium lactate, sodium metabisulfite, sodium nitrate, sodium nitrite, sodium phosphate, sodium propionate, sodium succinate, sodium sulfate, sodium sulfite, sodium tartrate, sodium thiosulfate, sorbitol, sucrose, tartaric acid, triethanolamine, urea, urethan, uridine and zinc sulfate. In certain embodiments, the tonicity adjusting agent is sodium chloride. In these embodiments, the pharmacologically suitable fluid is aqueous saline. The storage temperature of the compositions provided herein also has been found to affect the stability of the composition. Compositions stored at a lower temperature exhibit improved stability over formulations stored at higher temperatures. The effect of temperature on the rate constant of decomposition at pH 5, a buffer concentration of 5 mM, and an ionic strength of 0.05, was linear according to Arrhenius kinetics, i.e., when Ln kobs was plotted against 1/T, where T is the temperature in degree Kelvin. The estimated shelf-life of formoterol in the compositions provided herein is significantly greater than that reported for known formoterol compositions. The estimated shelf-life of formoterol in the compositions provided herein is about 6.2 years, at 5° C. and about 7.5 months, or at 25° C. The estimated formoterol concentrations in the compositions provided herein as a function of storage time at 5° C. and usage time at 25° C. was determined. It is estimated that greater than 90% of the initial formoterol present in the composition remains after 3 months of usage time at 25° C. and 3 years of storage time at 5° C. as well as after 0.5 months of usage time at 25 ° C. and 1 year of storage time at 5° C. In one embodiment, the compositions provided herein are prepared containing formoterol fumarate at a nominal concentration of 0.1 mg/mL at the indicated pH and citric acid/phosphate buffer concentrations. The solutions were stored at 60° C. In these compositions, formoterol is relatively more stable at a pH from about 4 to about 5, and is also more stable at lower buffer concentration. The compositions provided herein also may include excipients and additives. The particular excipient or additive for use in the compositions for long term storage provided herein may be determined empirically using methods well known to those of skill in the art (see, e.g., the Examples). Excipients and additives are any pharmacologically suitable and therapeutically useful substance which is not an active substance. Excipients and additives generally have no pharmacological activity, or at least no undesirable pharmacological activity. The excipients and additives include, but are not limited to, surfactants, stabilizers, complexing agents, antioxidants, or presevatives which prolong the duration of use of the finished pharmaceutical formulation, flavorings, vitamins, or other additives known in the art. Complexing agents include, but are not limited to, ethylenediaminetetraacetic acid (EDTA) or a salt thereof, such as the disodium salt, citric acid, nitrilotriacetic acid and the salts thereof. In one embodiment, the complexing agent is EDTA. Preservatives include, but are not limited to, those that protect the solution from contamination with pathogenic particles, including benzalkonium chloride or benzoic acid, or benzoates such as sodium benzoate. Antioxidants include, but are not limited to, vitamins, provitamins, ascorbic acid, vitamin E or salts or esters thereof. The compositions provided herein also may include a cosolvent, which increases the solubility of additives or the active ingredient(s). The particular cosolvent for use in the compositions for long term storage provided herein may be determined empirically using methods well known to those of skill in the art. Cosolvents for use herein include, but are not limited to, hydroxylated solvents or other polar solvents, such as alcohols such as isopropyl alcohol, glycols such as propylene glycol, polyethylene glycol, polypropylene glycol, glycol ether, glycerol, and polyoxyethylene alcohols. C. Preparation of Compounds for Use in the Compositions The preparation of the compounds used in the compositions provided herein is described below. Any such compound or similar compound may be synthesized according to a method discussed in general below or by only minor modification of the methods by selecting appropriate starting materials. Formoterol may be prepared according to the method disclosed in U.S. Pat. No. 3,994,974. Briefly, 4-benzyloxy-3-nitro-α-bromoacetophenone is reacted with N-benzyl-N-(1-methyl-2-p-methoxyphenylethyl)amine to form the α-aminoacetophenone. This compound was subjected to the following series of reactions: (i) reduction of the ketone with sodium borohydride; (ii) reduction of the nitro group with aqueous hydrochloric acid and iron powder; (iii) amine formylation with acetic anhydride and formic acid; and (iv) catalytic reduction over 10% palladium on carbon to afford formoterol free base. Crystallization of the ½ fumarate salt from ethanol provides (formoterol)·½ fumarate. The individual enantiomers of formoterol, 2-hydroxy-5-((1S)-1-hydroxy-2-(((1S)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide and 2-hydroxy-5-((1R)-1-hydroxy-2-(((1R)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide, may be prepared by the method disclosed in U.S. Pat. No. 6,040,344. Briefly, reaction of optically pure 4-benzyloxy-3-formamidostyrene oxide with an optically pure 4-methoxy-α-methyl-N-(phenylmethyl)benzeneethanamine, followed by debenzylation, affords the desired enantiomer of formoterol. Debenzylation may be accomplished by reduction with hydrogen gas in the presence of a noble metal catalyst, such as palladium on carbon. The required optically pure 4-benzyloxy-3-formamidostyrene oxide may be prepared from 4-benzyloxy-3-nitro-α-bromoacetophenone by (i) reduction with vorane in the presence of an optically pure aminoindanol, (ii) hydrogenation over platinum oxide catalyst, (iii) formylation with formic acid and acetic anhydride, and (iv) epoxide formation in the presence of potassium carbonate. The required optically pure 4-methoxy-α-methyl-N-(phenylmethyl)benzeneethanamine may be prepared from 4-methoxyphenylacetone by (i) reductive amination with benzylamine in the presence of hydrogen and a platinum catalyst, and (ii) crystallization of the desired optically pure amine from the resulting racemic mixture as its mandelic acid salt. D. Formulation of Pharmaceutical Compositions The compositions provided herien are prepared by procedures well known to those of skill in the art. For example, a formoterol fumarate solution may be prepared by the procedure of EXAMPLE 1. Briefly, a buffer solution having a pH and ionic strength of interest herein is prepared. In one embodiment, the buffer is a mixture of citric acid and sodium citrate, with sodium chloride added to achieve the desired ionic strength. Formoterol fumarate dihydrate is added to the buffer solution with agitation to produce a solution of the desired formoterol concentration. Exemplary formoterol concentrations is 0.0021 kg formoterol fumarate dihydrate/100 kg water. E. Evaluation of the Activity of the Compositions Standard physiological, pharmacological and biochemical procedures are available for testing the compositions provided herein to identify those that possess bronchodilatory activity. In vitro and in vivo assays that may be used to evaluate bronchodilatory activity are well known to those of skill in the art. See also, e.g., U.S. Pat. Nos. 3,994,974, and 6,068,833; German Patent No. 2,305,092; Kaumann et al. (1985) Naunyn-Schmied Arch. Pharmacol. 331:27-39; Lemoine et al. (1985) Naunyn-Schmied Arch. Pharmacol. 331:40-51; Tomioka et al. (1981) Arch. Int. Pharmacodyn. 250:279-292; Dellamary et al. (2000) Pharm. Res. 17(2):168-174; Rico-Mendez et al. (1999) Rev. Alerg. Mex. 46(5):130-135; Seberova et al. (2000) Respir. Med. 94(6):607-611; Lotvall et al. (1999) Can. Respir. J. 6(5):412-416; Campbell et al. (1999) Respir. Med. 93(4):236-244; Nightingale et al. (1999) Am. J. Respir. Crit. Care Med. 159(6):1786-1790; Lecaillon et al. (1999) Eur. J. Clin. Pharmacol. 55(2):131-138; Bartow et al. (1998) Drugs 55(2):303-322; Ekstrom et al. (1998) Respir. Med. 92(8):1040-1045; Ringdal et al. (1998) Respir. Med. 92(8):1017-1021; Totterman et al. (1998) Eur. Respir. J. 12(3):573-579; Palmqvist et al. (1997) Eur. Respir. J. 10 (11):2484-2489; Nielsen et al. (1997) Eur. Respir. J. 10(9):2105-2109; Ullman et al. (1996) Allergy 51(10):745-748; Selroos et al. (1996) Clin. Immunother. 6:273-299; and Schreurs et al. (1996) Eur. Respir. J. 9(8):1678-1683. F. Methods of Treatment of Bronchoconstrictive Disorders The compositions provided herein are used for treating, preventing, or ameliorating one or more symptoms of a bronchoconstrictive disorders in a subject. In one embodiment, the method includes administering to a subject an effective amount of a composition containing a bronchodilating agent, including, but not limited to, formoterol, whereby the disease or disorder is treated or prevented. The subject treated is, in certain embodiments, a mammal. The mammal treated is, in certain embodiments, a human. In another embodiment, the method provided herein includes oral administration of a composition provided herein. In certain embodiments herein, the composition is directly administered to a subject in need of such treatment via nebulization without dilution or other modification of the composition prior to administration. The methods for treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders, in another embodiment, further include administering one or more of (a), (b), (c) or (d) as follows: (a) a β2-adrenoreceptor agonist; (b) a dopamine (D2) receptor agonist; (c) a prophylactic therapeutic, such as a steroid; or (d) an anticholinergic agent; simultaneously with, prior to or subsequent to the composition provided herein. β2-Adrenoreceptor agonists for use in combination with the coimpositions provided herein include, but are not limited to, Albuterol (α1-(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); Bambuterol (dimethylcarbamic acid 5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-phenylene ester); Bitolterol (4-methylbenzoic acid 4-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,2-phenylene ester); Broxaterol (3-bromo-α-(((1,1-dimethylethyl)amino)methyl)-5-isoxazolemethanol); Isoproterenol (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Trimetoquinol (1,2,3,4-tetrahydro-1-((3,4,5-trimethoxyphenyl)methyl)-6,7-isoquinolinediol); Clenbuterol (4-amino-3,5-dichloro-α-(((1,1-diemthylethyl)amino)methyl)benzenemethanol); Fenoterol (5-(1-hydroxy-2-((2-(4-hydroxyphenyl)-1-methylethyl)amino)ethyl)-1,3-benzenediol); Formoterol (2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)-formanilide); (R,R)-Formoterol; Desformoterol ((R,R) or (S,S)-3-amino-4-hydroxy-α-(((2-(4-methoxyphenyl)-1-methylethyl)amino)methyl)benzenemethanol); Hexoprenaline (4,4′-(1,6-hexanediyl)-bis(imino(1-hydroxy-2,1-ethanediyl)))bis-1,2-benzenediol); Isoetharine (4-(1-hydroxy-2-((1-methylethyl)amino)butyl)-1,2-benzenediol); Isoprenaline (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Metaproterenol (5-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,3-benzenediol); Picumeterol (4-amino-3,5-dichloro-α-(((6-(2-(2-pyridinyl)ethoxy)hexyl)amino)methyl)benzenemethanol); Pirbuterol (α6-(((1,1-dimethylethyl)amino)methyl)-3-hydroxy-2,6-pyridinemethanol); Procaterol (((R*,S*)-(±)-8-hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-2(1H)-quinolinone); Reproterol ((7-(3-((2-(3,5-dihydroxyphenyl)-2-hydroxyethyl)amino)-propyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione); Rimiterol (4-(hydroxy-2-piperidinylmethyl)-1,2-benzenediol); Salbutamol ((±)-α1-(((1,1-dimethylethyl)amino)-methyl)-4-hydroxy-1,3-benzenedimethanol); (R)-Salbutamol; Salmeterol ((±)-4-hydroxy-α1-(((6-(4-phenylbutoxy)hexyl)amino)methyl)-1,3-benzenedimethanol); (R)-Salmeterol; Terbutaline (5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-benzenediol); Tulobuterol (2-chloro-α-(((1,1-dimethylethyl)amino)methyl)benzenemethanol); and TA-2005 (8-hydroxy-5-((1R)-1-hydroxy-2-(N-((1R)-2-(4-methoxyphenyl)-1-methylethyl)amino)ethyl)carbostyril hydrochloride). Dopamine (D2) receptor agonists include, but are not limited to, Apomorphine ((r)-5,6,6a,7-tetrahydro-6-methyl-4H-dibenzo[de,g]quinoline-10,11-diol); Bromocriptine ((5′α)-2-bromo-12′-hydroxy-2′-(1-methylethyl)-5′-(2-methylpropyl)ergotaman-3′,6′,18-trione); Cabergoline ((8β)-N-(3-(dimethylamino)propyl)-N-((ethylamino)carbonyl)-6-(2-propenyl)ergoline-8-carboxamide); Lisuride (N′-((8α)-9,10-didehydro-6-methylergolin-8-yl)-N,N-diethylurea); Pergolide ((8α)-8-((methylthio)methyl)-6-propylergoline); Levodopa (3-hydroxy-L-tryrosine); Pramipexole ((s)-4,5,6,7-tetrahydro-N6-propyl-2,6-benzothiazolediamine); Quinpirole hydrochlrodie (trans-(−)-4aR-4,4a,5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolo[3,4-g]quinoline hydrochloride); Ropinirole (4-(2-(dipropylamino)ethyl)-1,3-dihydro-2H-indol-2-one); and Talipexole (5,6,7,8-tetrahydro-6-(2-propenyl)-4H-thiazolo[4,5-d]azepin-2-amine). Other dopamine D2 receptor agonists for use herein are disclosed in International Patent Application Publication No. WO 99/36095. Prophylactic therapeutics for use in combination therapy herein include steroidal anti-inflammatory agents, including, but not limited to, beclomethasone dipropionate (BDP), beclomethasone monopropionate (BMP), flunisolide, triamcinolone acetonide, dexamethasone, tipredane, ciclesonid, rofleponide, mometasone, mometasone furoate (ASMANEX® TWISTHALER™, Schering-Plough Corporation, Kenilworth, N.J.), RPR 106541, having the formula fluticasone or fluticasone propionate and budesonide or by way of sodium cromoglycate or nedocromil sodium. Anticholinergic agents for use herein include, but are not limited to, ipratropium bromide, oxitropium bromide, atropine methyl nitrate, atropine sulfate, ipratropium, belladonna extract, scopolamine, scopolamine methobromide, homatropine methobromide, hyoscyamine, isopriopramide, orphenadrine, benzalkonium chloride, tiotropium bromide and glycopyrronium bromide. In certain embodiments, the compositions contain an anticholinergic agent, such as ipratropium bromide, at a concentration of about 100 μg/mL to about 500 μg/mL, or 100 μg/mL to 500 μg/mL. In other embodiments, ipratropium bromide concentration is about 150 μg/mL to about 350 μg/mL, or 150 μg/mL to 350 μg/mL. In other embodiments, the compositions for use in the methods herein contain ipratropium bromide at a concentration of about 200 μg/mL to about 300 μg/mL, or 200 μg/mL to 300 μg/mL. In other embodiments, the compositions for use in the methods herein contain ipratropium bromide at a concentration of about 250 μg/mL, or 250 μg/mL. Other active ingredients for use herein in combination therapy, include, but are not limited to, IL-5 inhibitors such as those disclosed in U.S. Pat. Nos. 5,668,110, 5,683,983, 5,677,280 and 5,654,276; antisense modulators of IL-5 such as those disclosed in U.S. Pat. No. 6,136,603; milrinone (1,6-dihydro-2-methyl-6-oxo-[3,4′-bipyridine]-5-carbonitrile milrinone lactate; tryptase inhibitors such as those disclosed in U.S. Pat. No. 5,525,623; tachykinin receptor antagonists such as those disclosed in U.S. Pat. Nos. 5,691,336, 5,877,191, 5,929,094, 5,750,549 and 5,780,467; leukotriene receptor antagonists such as montelukast sodium (SINGULAR®, R-(E)]-1-[[[1-[3-[2-(7-chloro-2-quinolinyl)ethenyl]phenyl]-3-[2-(1-hydroxy-1-methylethyl)phenyl]-propyl]thio]methyl]cyclopropaneacetic acid, monosodium salt), 5-lypoxygenase inhibitors such as zileuton (ZYFLO®, Abbott Laboratories, Abbott Park, Ill.), and anti-IgE antibodies such as XOLAIR® (recombinant humanized anti-IgE monoclonal antibody (CGP 51901; IGE 025A; rhuMAb-E25), Genentech, Inc., South San Francisco, Calif.). The bronchoconstrictive disorder to be treated, prevented, or whose one or more symptoms are to be ameliorated is associated with asthma, including, but not limited to, bronchial asthma, allergic asthma and intrinsic asthma, e.g., late asthma and airway hyper-responsiveness; and, particularly in embodiments where an anticholinergic agent is used, other chronic obstructive pulmonary diseases (COPDs), including, but not limited to, chronic bronchitis, emphysema, and associated cor pulmonale (heart disease secondary to disease of the lungs and respiratory system) with pulmonary hypertension, right ventricular hypertrophy and right heart failure. COPD is frequently associated with cigarette smoking, infections, environmental pollution and occupational dust exposure. G. Nebulizers The compositions provided herein are intended for administration to a subject in need of such treatment via nebulization. Nebulizers that nebulize liquid formulations containing no propellant are suitable for use with the compositions provided herein. The nebilizer and can be unit dose or multidose. Nebulizers are available from, e.g., Pari GmbH (Starnberg, Germany), DeVilbiss Healthcare (Heston, Middlesex, UK), Healthdyne, Vital Signs, Baxter, Allied Health Care, Invacare, Hudson, Omron, Bremed, AirSep, Luminscope, Medisana, Siemens, Aerogen, Mountain Medical, Aerosol Medical Ltd. (Colchester, Essex, UK), AFP Medical (Rugby, Warwickshire, UK), Bard Ltd. (Sunderland, UK), Carri-Med Ltd. (Dorking, UK), Plaem Nuiva (Brescia, Italy), Henleys Medical Supplies (London, UK), Intersurgical (Berkshire, UK), Lifecare Hospital Supplies (Leies, UK), Medic-Aid Ltd. (West Sussex, UK), Medix Ltd. (Essex, UK), Sinclair Medical Ltd. (Surrey, UK), and many others. Nebulizers for use herein include, but are not limited to, jet nebulizers (optionally sold with compressors), ultrasonic nebulizers, and others. Exemplary jet nebulizers for use herein include Pari LC plus/ProNeb, Pari LC plus/ProNeb Turbo, Pari LC plus/Dura Neb 1000 & 2000, Pari LC plus/Walkhaler, Pari LC plus/Pari Master, Pari LC star, Omron CompAir XL Portable Nebulizer System (NE-C 18 and JetAir Disposable nebulizer), Omron CompAir Elite Compressor Nebulizer System (NE-C21 and Elite Air Reusable Nebilizer), Pari LC Plus or Pari LC Star nebulizer with Proneb Ultra compressor, Pulmo-aide, Pulmo-aide LT, Pulmo-aide traveler, Invacare Passport, Inspiration Healthdyne 626, Pulmo-Neb Traverler, DeVilbiss 646, Whisper Jet, Acorn II, Misty-Neb, Allied aerosol, Schuco Home Care, Lexan Plasic Pocet Neb, SideStream Hand Held Neb, Mobil Mist, Up-Draft, Up-Draft II, T Up-Draft, ISO-NEB, AVA-NEB, Micro Mist, and PulmoMate. Exemplary ultrasonic nebulizers for use herein include MicroAir, UltraAir, Siemens Ultra Nebulizer 145, CompAir, Pulmosonic, Scout, 5003 Ultrasonic Neb, 5110 Ultrasonic Neb, 5004 Desk Ultrasonic Nebulizer, Mystique Ultrasonic, Luminscope's Ultrasonic Nebulizer, Medisana Ultrasonic Nebulizer, Microstat Ultrasonic Nebulizer, and MABISMist Hand Held Ultrasonic Nebulizer. Other nebulizers for use herein include 5000 Electromagnetic Neb, 5001 Electromagnetic Neb 5002 Rotary Piston Neb, Lumineb I Piston Nebulizer 5500, AERONEB™ Portable Nebulizer System, AERODOSE™ Inhaler, AeroEclipse Breath Actuated Nebulizer, HALOLITE™ system (Profile Therapeutics), AKITA® systems (InaMed, Germany), Mystic system (BattellePharma), RESPIMAT® (Boehringer Ingelheim), AERX® (Aradigm), and E-FLOW™ (Pari). Depending on the nebulizer used, the volume of the formoterol inhalation solution nebulized in one embodiment, is about 0.1 mL to 3 mL, or 0.1 mL to 3 mL. In another embodiment, the volume is about 2 mL, or 2 mL. In another embodiment, the volume is about 1 mL, or 1 mL. In another embodiment, the volume is about 0.5 mL, or 0.5 mL. H. Articles of Manufacture The compositions provided herein may be packaged as articles of manufacture containing packaging material, a composition provided herein, which is useful for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction, and a label that indicates that the composition is used for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction. The articles of manufacture provided herein contain packaging materials. Packaging materials for use in packaging pharmaceutical products are well known to those of skill in the art. See, e.g., U.S. Pat. Nos. 5,323,907, 5,052,558 and 5,033,252. Examples of pharmaceutical packaging materials include, but are not limited to, blister packs, bottles, tubes, inhalers, pumps, bags, vials, containers, syringes, bottles, and any packaging material suitable for a selected formulation and intended mode of administration and treatment. In one embodiment herein, the compositions are packaged with a nebulizer for direct administration of the composition to a subject in need thereof. The following examples are included for illustrative purposes only and are not intended to limit the scope of the invention. EXAMPLE 1 Preparation of Formoterol Inhalation Solution Formulation: Appropriate quantities of the raw materials are weighed for the 100 Kg batch as shown below: 20 μg/mL* 10 μg/mL* Formoterol fumarate dihydrate 0.0021 kg 0.00105 kg Citric acid monohydrate USP 0.135 kg 0.135 kg Sodium Citrate dihydrate USP 0.400 kg 0.400 kg Sodium chloride USP 0.785 kg 0.785 kg Purified water USP q.s. to 100 kg q.s. to 100 kg *Concentration of formoterol fumarate (anhydrous) In a clean stainless steel (SS) tank fitted with bottom drain, 75% of the required amount of purified water is added. Samples are taken for pH, conductivity, and microbiological testing. Citric acid monohydrate, sodium citrate dihydrate and sodium chloride are added to the tank and mixed for 15 minutes to dissolve. A sample is taken at this point to check pH. Formoterol fumarate dihydrate is added at this point and mixed for about 75 minutes to dissolve all active raw material. Purified water is used to adjust to final volume. The formulation is mixed for an additional 30 minutes and samples for pH and assay are taken based on which the formulation is released for filling. The bulk solution is filled into low density polyethylene (LDPE) vials (2 mL fill) in a form-fill-seal (FFS) machine. The released drug product solution is transferred from the formulation tank through sanitary delivery lines into the FFS machine. The individual vials are overwrapped with a suitable foil laminate. EXAMPLE 2 Procedure for Stability Testing of Formoterol Solutions Stability samples of the solution prepared in EXAMPLE 1 and solution of formoterol fumarate (20 μg/mL) and ipratropium bromide (250 μg/mL) were placed in LDPE vials and stored in stability ovens at accelerated temperatures. At selected time points, aliquots of the samples were removed from the vials. The formoterol concentrations of the samples were analyzed by high performance liquid chromatography. Provided herein is the stability data for exemplary formulations containing formoterol and formoterol in combination with ipratropium bromide. Stability data on formoterol (20 μg/mL) and formoterol fumarate/ipratropium bromide combination (20 μg/ml and 250 μg/mL): Assay as percent of label claim Formterol Formoterol fumarate/ipratropium bromide Inhalation solution inhalation solution Storage condition Formoterol Formoterol Ipratropium Initial 100 100.5 101.2 5° C./3 months 96.7 100 101.6 25° C./3 months 94.5 100 101.2 Since modifications will be apparent to those of skill in this art, it is intended that this invention be limited only by the scope of the appended claims. | <SOH> BACKGROUND <EOH>Bronchoconstrictive disorders affect millions worldwide. Such disorders include asthma (including bronchial asthma, allergic asthma and intrinsic asthma, e.g., late asthma and airway hyper-responsiveness), chronic bronchitis and other chronic obstructive pulmonary diseases. Compounds having β 2 -adrenoreceptor agonist activity have been developed to treat these conditions. Such compounds include, but are not limited to, Albuterol (α 1 -(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); Bambuterol (dimethylcarbamic acid 5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-phenylene ester); Bitolterol (4-methylbenzoic acid 4-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,2-phenylene ester); Broxaterol (3-bromo-α-(((1,1-dimethylethyl)amino)methyl)-5-isoxazolemethanol); Isoproterenol (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Trimetoquinol (1,2,3,4-tetrahydro-1-((3,4,5-trimethoxyphenyl)methyl)-6,7-isoquinolinediol); Clenbuterol (4-amino-3,5-dichloro-α-(((1,1-diemthylethyl)amino)methyl)benzenemethanol); Fenoterol (5-(1-hydroxy-2-((2-(4-hydroxyphenyl)-1-methylethyl)amino)ethyl)-1,3-benzenediol); Formoterol (2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methyl-ethyl)amino)ethyl)formanilide); (R,R)-Formoterol; Desformoterol ((R,R) or (S,S)-3-amino-4-hydroxy-α-(((2-(4-methoxyphenyl)-1-methylethyl)amino)methyl)benzene-methanol); Hexoprenaline (4,4′-(1,6-hexanediyl)-bis(imino(1-hydroxy-2,1-ethane-diyl)))bis-1,2-benzenediol); Isoetharine (4-(1-hydroxy-2-((1-methylethyl)amino)butyl)-1,2-benzenediol); Isoprenaline (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Metaproterenol (5-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,3-benzenediol); Picumeterol (4-amino-3,5-dichloro-α-(((6-(2-(2-pyridinyl)ethoxy)hexyl)-amino)methyl)benzenemethanol); Pirbuterol (α 6 -(((1,1-dimethylethyl)amino)methyl)-3-hydroxy-2,6-pyridinemethanol); Procaterol (((R*,S*)-(±)-8-hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-2(1H)-quinolinone); Reproterol ((7-(3-((2-(3,5-dihydroxyphenyl)-2-hydroxyethyl)amino)propyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione); Rimiterol (4-(hydroxy-2-piperidinylmethyl)-1,2-benzenediol); Salbutamol ((±)-α 1 -(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); (R)-Salbutamol; Salmeterol ((±)-4-hydroxy-α 1 -(((6-(4-phenylbutoxy)hexyl)amino)methyl)-1,3-benzenedimethanol); (R)-Salmeterol; Terbutaline (5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-benzenediol); Tulobuterol (2-chloro-α-(((1,1-dimethyl-ethyl)amino)methyl)benzenemethanol); and TA-2005 (8-hydroxy-5-((1R)-1-hydroxy-2-(N-((1R)-2-(4-methoxyphenyl)-1-methylethyl)amino)ethyl)carbostyril hydrochloride). These compounds are typically formulated for inhalation therapy. Aqueous or liquid formulations are preferred over solid formulations. Powdered formulations are more difficult to administer, particularly to the young and elderly who are most often the patients in need of such therapy. Compounds, such as formoterol are not adequately stable in aqueous solutions to be formulated as liquids. Hence there is a need for formulations of compounds, such as formoterol, in a form that can be conveniently administered and that are stable for extended periods of time. | <SOH> SUMMARY <EOH>Compositions and methods for treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders are provided. The compositions provided herein are stable solutions of a bronchodilating agent, or a derivative thereof, in a pharmacologically suitable fluid that contains water, that are stable during long term storage. The compositions are suitable for direct administration to a subject in need thereof. Pharmacologically suitable fluids include, but are not limited to, polar fluids, including protic fluids. In certain embodiments herein, the compositions are aqueous solutions. The compositions provided herein possess an estimated shelf-life of greater than 1, 2 or 3 months usage time at 25° C. and greater than or equal to 1, 2 or 3 years storage time at 5° C. In certain of these embodiments, using Arrhenius kinetics, >80% or >85% or >90% or >95% estimated bronchodilating agent remains after such storage. These compositions are particularly useful for administration via nebulization. In certain embodiments herein, the subject is a mammal. In other embodiments, the subject is a human. The compositions provided herein are formulated to remain stable over a relatively long period of time. For example, the compositions provided herein are stored between −15° C. and 25° C., or between 2° C. and 8° C., and remain stable for the desired time. In one embodiment, the compositions are stored at 5° C. In other embodiment, the compositions are stored at 25° C. Among the bronchodilating agents for use herein are Albuterol (α 1 -(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); Bambuterol (dimethylcarbamic acid 5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-phenylene ester); Bitolterol (4-methylbenzoic acid 4-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,2-phenylene ester); Broxaterol (3-bromo-α-(((1,1-dimethylethyl)amino)-methyl)-5-isoxazolemethanol); Isoproterenol (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Trimetoquinol (1,2,3,4-tetrahydro-1-((3,4,5-trimethoxyphenyl)methyl)-6,7-isoquinolinediol); Clenbuterol (4-amino-3,5-dichloro-α-(((1,1-diemthylethyl)amino)methyl)benzenemethanol); Fenoterol (5-(1-hydroxy-2-((2-(4-hydroxyphenyl)-1-methylethyl)amino)ethyl)-1,3-benzenediol); Formoterol (2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)-formanilide); (R,R)-Formoterol; (S,S)-Formoterol; Desformoterol ((R,R) or (S,S)-3-amino-4-hydroxy-α-(((2-(4-methoxyphenyl)-1-methylethyl)amino)methyl)benzene-methanol); Hexoprenaline (4,4′-(1,6-hexanediyl)-bis(imino(1-hydroxy-2,1-ethane-diyl)))bis-1,2-benzenediol); Isoetharine (4-(1-hydroxy-2-((1-methylethyl)amino)butyl)-1,2-benzenediol); Isoprenaline (4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol); Metaproterenol (5-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-1,3-benzenediol); Picumeterol (4-amino-3,5-dichloro-α-(((6-(2-(2-pyridinyl)ethoxy)hexyl)-amino)methyl)benzenemethanol); Pirbuterol (α 6 -(((1,1-dimethylethyl)amino)methyl)-3-hydroxy-2,6-pyridinemethanol); Procaterol (((R*,S*)-(±)-8-hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-2(1H)-quinolinone); Reproterol ((7-(3-((2-(3,5-dihydroxyphenyl)-2-hydroxyethyl)amino)propyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione); Rimiterol (4-(hydroxy-2-piperidinylmethyl)-1,2-benzenediol); Salbutamol ((±)-α 1 -(((1,1-dimethylethyl)amino)methyl)-4-hydroxy-1,3-benzenedimethanol); (R)-Salbutamol; Salmeterol ((±)-4-hydroxy-α 1 -(((6-(4-phenylbutoxy)hexyl)amino)methyl)-1,3-benzenedimethanol); (R)-Salmeterol; Terbutaline (5-(2-((1,1-dimethylethyl)amino)-1-hydroxyethyl)-1,3-benzenediol); Tulobuterol (2-chloro-α-(((1,1-dimethyl-ethyl)amino)methyl)benzenemethanol); and TA-2005 (8-hydroxy-5-((1R)-1-hydroxy-2-(N-((1R)-2-(4-methoxyphenyl)-1-methylethyl)amino)ethyl)carbostyril hydrochloride). Of particular interest herein is formoterol, having the formula: Formoterol for use in the compositions and methods provided herein includes 2-hydroxy-5-((1RS)-1-hydroxy-2-(((1RS)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide; or a stereoisomer thereof; and also includes the single enantiomers 2-hydroxy-5-((1S)-1-hydroxy-2-(((1S)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide and 2-hydroxy-5-((1R)-1-hydroxy-2-(((1R)-2-(p-methoxyphenyl)-1-methylethyl)amino)ethyl)formanilide. In certain embodiments, the compositions are administered via nebulization. Administration of a nebulized aerosol is preferred over the use of dry powders for inhalation in certain subject populations, including pediatric and geriatric groups. In one embodiment, the compositions for use in the methods provided herein contain a pharmaceutically acceptable derivative of formoterol. In another embodiment, the compositions for use in the methods provided herein contain a pharmaceutically acceptable salt of formoterol. Pharmaceutically acceptable salts include, but are not limited to, salts of mineral acids, such as but not limited to hydrochlorides and sulfates; and salts of organic acids, such as but not limited to acetates, lactates, malates, tartrates, citrates, ascorbates, succinates, butyrates, valerates and fumarates. In one embodiment, the compositions for use in the methods provided herein contain formoterol fumarate or formoterol fumarate dihydrate. In another embodiment, the compositions for use in the methods provided herein contain formoterol tartrate. Also provided herein are combinations containing a composition provided herein and a nebulizer. The combinations can be packaged as kits, which optionally contain other components, including instructions for use of the nebulizer. Any nebulizer is contemplated for use in the kits and methods provided herein. In particular, the nebulizers for use herein nebulize liquid formulations, including the compositions provided herein, containing no propellant. The nebulizer may produce the nebulized mist by any method known to those of skill in the art, including, but not limited to, compressed air, ultrasonic waves, or vibration. The nebulizer may further have an internal baffle. The internal baffle, together with the housing of the nebulizer, selectively removes large droplets from the mist by impaction and allows the droplets to return to the reservoir. The fine aerosol droplets thus produced are entrained into the lung by the inhaling air/oxygen. Methods for the treatment, prevention, or amelioration of one or more symptoms of bronchoconstrictive disorders, including, but not limited to, asthma, including, but not limited to, bronchial asthma, allergic asthma and intrinsic asthma, e.g., late asthma and airway hyper-responsiveness; chronic bronchitis; and other chronic obstructive pulmonary diseases are provided. The methods involve administering an effective amount of a pharmaceutical composition provided herein to a subject in need of such treatment. Articles of manufacture, containing packaging material, a composition provided herein, which is useful for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction, and a label that indicates that the composition is used for treatment, prevention or amelioration of one or more symptoms of diseases or disorders associated with undesired and/or uncontrolled bronchoconstriction, are also provided. detailed-description description="Detailed Description" end="lead"? | 20040709 | 20080325 | 20050113 | 91655.0 | 3 | HENLEY III, RAYMOND J | BRONCHODILATING BETA-AGONIST COMPOSITIONS AND METHODS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,887,949 | ACCEPTED | Output driver for an integrated circuit and method for driving an output driver | One embodiment of the invention provides an output driver for an integrated circuit. The output driver has a driver circuit for driving an input signal onto an output line. The driver circuit is dimensioned in such a way as to supply a current intensity dependent on the input signal to be driven and/or a potential dependent on the input signal to be driven on the output line. The current value and/or the potential value lie in a current intensity range and/or potential range defined by a predetermined specification. The driver strength of the driver circuit may be set in accordance with a control signal. A measuring circuit is provided to measure the current intensity of the current flowing on the output line and/or the potential of the output line. A control circuit serves for setting the driver strength of the driver circuit so that the potential on the output line is set to a potential value and/or the current intensity is set to a current value, wherein the set potential value and the set current value may lie in a lower power range of the current intensity range and/or potential range prescribed by the specification. | 1. An output driver for an integrated circuit, comprising: a driver circuit for driving an input signal of the output driver onto an output line; a measuring circuit for measuring at least one of an output line current and an output line potential; and a control unit for providing a control signal for setting a driver strength of the driver circuit to provide at least one of the output line potential and the output line current in a desired power range of a specification-prescribed potential range and a specification-prescribed current range. 2. The output driver of claim 1, wherein the desired power range is determined by one of a specification-prescribed lower current limit value, a specification-prescribed lower current limit value adjusted with a tolerance magnitude, a specification-prescribed lower potential limit value and a specification-prescribed lower potential limit value adjusted with the tolerance magnitude. 3. The output driver of claim 1, wherein the driver circuit includes a pull-up path defined by a first maximum and minimum current/potential (I/V) characteristic curve and a pull-down path defined by a second maximum and minimum I/V characteristic curve and wherein the desired power range is determined depending on respectively activated pull-up path and pull-down path of the driver circuit. 4. The output driver of claim 1, wherein the desired power range corresponds to a lower portion of the specification-prescribed potential range and a lower portion of the specification-prescribed current range. 5. The output driver of claim 1, wherein the driver circuit further comprises a setting circuit for receiving the control signal from the control unit and for setting the driver strength of the driver circuit. 6. The output driver of claim 1, further comprising a comparator unit for comparing at least one of the measured output line current and the measured output line potential respectively with at least one of a reference current value and a reference potential value. 7. The output driver of claim 6, wherein the control unit further comprises an evaluation unit connected to the comparator unit, the evaluation unit configured to change the control signal based upon a result from the comparator unit. 8. The output driver of claim 7, wherein the evaluation unit comprises a counter. 9. The output driver of claim 6, wherein the control unit further comprises a multiplexer connected to provide a first reference potential and a second reference potential to the comparator unit. 10. The output driver of claim 9, wherein the multiplexer selects the first reference potential and the second reference potential supplied to the comparator unit based on the input signal. 11. The output driver of claim 10, wherein the multiplexer includes an input connected to the input signal of the driver circuit, and wherein the input signal is utilized to determine whether a high level or a low level is to be output by the driver circuit. 12. The output driver of claim 9, wherein the multiplexer selects the first reference voltage and the second reference voltage supplied to the comparator unit based on an output signal on the output line. 13. The output driver of claim 9, wherein the control unit further comprises a voltage divider connected provide a plurality of reference potentials selectable by the multiplexer. 14. A method for driving an output driver for an integrated circuit having a driver circuit driving an input signal onto an output line, comprising: measuring at least one of an output line current and an output line potential; and controlling a driver strength of the driver circuit to set at least one of the current and the potential in at least one of a specification-prescribed current range and a specification-prescribed potential range, respectively, wherein the driver strength is set such that the potential and the current intensity lie in a lower power range of the specification-prescribed current range and the specification-prescribed potential range. 15. The method of claim 14, wherein the driver strength of the driver circuit is controlled in a manner selected from continuously, periodically and in accordance with a setting signal. 16. The method of claim 14, further comprising: comparing at least one of the measured output line current and the measured output line potential respectively with at least one of a reference current value and a reference potential value; and changing a control signal for setting the driver strength supplied to the driver circuit based upon a result from the comparison. 17. The method of claim 16, further comprising: determining whether a high level or a low level is to be output by the driver circuit based on the input signal; and selecting a first reference voltage and a second reference voltage from a plurality of voltage references to be compared against the measured output line potential, the first reference voltage and the second reference voltage selected based on the determination of high level or low level. 18. An output driver for an integrated circuit, comprising: a driver means for driving an input signal of the output driver onto an output line; and a control means for providing a control signal for setting a driver strength of the driver means to provide at least one of an output line potential and an output line current in a lower power range of a specification-prescribed potential range and a specification-prescribed current range, the control means comprising: a comparator means for comparing at least one of the output line current and the output line potential respectively with at least one of a reference current value and a reference potential value; and an evaluation means for changing the control signal based upon a comparison result from the comparator means. 19. The output driver of claim 18, wherein the control means further comprises: a multiplexing means connected to provide a first reference voltage and a second reference voltage to the comparator means for the output line potential to be compared; and a voltage divider means for providing a plurality of reference voltages for selection by the multiplexing means. 20. The output driver of claim 19, wherein the multiplexing means includes an input connected to the input signal of the driver circuit, wherein the input signal is utilized to determine whether a high level or a low level is to be output by the driver circuit and wherein the multiplexer selects the first reference voltage and the second reference voltage supplied to the comparator unit based on the input signal. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims foreign priority benefits under 35 U.S.C. §119 to co-pending German patent application number 103 31 607.8, filed Jul. 12, 2003. This related patent application is herein incorporated by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to an output driver for an integrated circuit having a driver circuit for driving an input signal onto an output line. The invention furthermore relates to a method for driving an output driver for an integrated circuit. 2. Description of the Related Art Integrated circuits usually have output drivers for driving signals which have been generated in circuits of the integrated circuit on external lines connected to the integrated circuit. To define the driver behavior of the output drivers, a specification is provided which, depending on the output driver, provides an upper and a lower current value or an upper and lower potential value depending on the signal state (high level or low level) of the output signal to be driven. In this case, the specification respectively specifies an upper and lower current-voltage characteristic curve for the activated pull-up path of the driver circuit and for the pull-down path of the driver circuit, which characteristic curve in each case defines a current intensity range within which the current intensity through the relevant path and thus through the output line must be. Depending on whether a high or low level is intended to be driven by the output driver, the specification prescribes different upper and lower current-voltage characteristic curves for the pull-up path and the pull-down path. Usually, the specifications for integrated circuits, in particular for SDRAM and DDR memory circuits, provide a relatively large current intensity range or potential range for the output drivers, so that it is simpler to achieve the specification-conforming current intensity values or potential values for process cut-off values, temperatures and voltages (PVT). The specification-conforming current intensity ranges or voltage ranges of the pull-up paths and pull-down paths may signify great differences with regard to the power consumption depending on the position of the actual potential value or current value within the specification, since more power is required in an upper current intensity range and/or in an upper potential range than if the output signal is in a lower range of the permissible predetermined potential window and/or current intensity window. However, the exact potential value or current value with which the signal is driven with the aid of the output driver cannot be established from the outset since it is necessary to take account of process deviations, temperature fluctuations and voltage fluctuations which might have the effect that the relevant value is outside the specification-conforming window. Moreover, different loads are possible at the outputs of the integrated circuit, so that this may result in different potential values or current values depending on the connected components or the switching states thereof. SUMMARY OF THE INVENTION It is an object of the present invention to provide an integrated circuit and a method for controlling an output driver which are able to reduce the power consumption of the integrated circuit and to ensure that the corresponding potential value or current value at the output of the output driver is within the specification. A first aspect of the present invention provides an output driver for an integrated circuit. The output driver has a driver circuit for driving an input signal onto an output line. The driver circuit is dimensioned in such a way as to supply a current intensity dependent on the input signal to be driven and/or a potential dependent on the input signal to be driven on the output line. The current value and/or the potential value lie in a current intensity range and/or potential range defined by a predetermined specification. The driver strength of the driver circuit may be set in accordance with a control signal. A measuring circuit is provided to measure the current intensity of the current flowing on the output line and/or the potential of the output line. A control circuit serves for setting the driver strength of the driver circuit so that the potential on the output line is set to a potential value and/or the current intensity is set to a current value, wherein the set potential value and the set current value may lie in a lower power range of the current intensity range and/or potential range prescribed by the specification. In this way, one aspect of the invention provides an output driver for an integrated circuit which makes it possible to set the current value and/or the potential value on the output line in a lower power range, i.e., to operate the integrated circuit at an operating point at which the power consumption of the output driver can be reduced, but without permitting a current value or potential value outside the specification-conforming limits. The current intensity ranges and/or potential ranges permissible in accordance with the specification are comparatively large on account of process fluctuations in the production of the integrated circuits, a high operating temperature range in which the integrated circuit can be operated reliably, and voltage fluctuations that may occur. It follows from this that the output driver has a different power consumption depending on the current intensity or potential within the permissible windows with which the output driver drives a signal onto the output line. Consequently, the range of possible power consumptions is likewise very large on account of the large range of values for the potential and the current intensity. In order not to reach an operating range outside the specification on account of temperature fluctuations, process fluctuations or the like, the driver strength of the output driver may be set by means of the production process such that the input signal to be driven is driven with a current intensity and a potential which essentially lies centrally within the current intensity range or potential range prescribed by the specification. One aspect of the invention also provides a control circuit which influences the driver strength of the driver circuit. The driver strength of the driver circuit may be set by the control circuit in such a way that the current intensity and/or the potential on the output line, depending on the input signal to be driven, lies in a lower power range of the current intensity range and/or potential range prescribed by the specification, i.e., the power consumption of the output driver is reduced within the permissible range. As a result, it is possible to take into account the process fluctuations during the production of the integrated circuit, the respective operating temperature, the potential fluctuations, e.g., of the supply voltages, and the load connected to the output driver such that the driver circuit of the output driver supplies a potential value and a current intensity value lying within the specification-conforming range limits, albeit in a lower power range to reduce the power consumption of the output driver in comparison with the energy consumption of a noncontrolled driver circuit. One aspect of the invention provides that the lower power range is determined by a lower current limit value prescribed by the specification and a lower current limit value increased by a tolerance magnitude and/or by a lower potential value prescribed by the specification and a lower potential value increased by a tolerance magnitude. In this way, a lower power range can be defined in the current or potential value prescribed by the specification. The specification may specify a first maximum and minimum current-voltage characteristic curve for a pull-up path of the driver circuit and a second maximum and minimum current-voltage characteristic curve for a pull-down path of the driver circuit. Depending on the respectively driven pull-up path or pull-down path of the driver circuit, the lower power range is determined depending on the current intensity range which is prescribed by the specification and is specified by the first or second current-voltage characteristic curve. The control circuit may comprise a comparator device for comparing the measured current value or the measured potential value with a reference current value or a reference potential value dependent on the specification. The reference current value or the reference potential value may be provided by a reference voltage source or a reference current source. A further aspect of the present invention provides a method for driving an output driver for an integrated circuit having a driver circuit. The driver circuit serves for driving an output signal dependent on an input signal with a current intensity and/or a potential onto an output line. The current intensity of the current flowing on the output line and/or the potential on the output line are measured. The driver strength of the driver circuit is controlled in such a way as to set the current intensity and/or the potential in a current intensity range and/or potential range defined by a predetermined specification. Furthermore, the driver strength is set in such a way that the potential value and/or the current intensity lie in a lower power range of the current intensity range and potential range prescribed by the specification. The method according to the invention affords the possibility of setting the driver power of an output driver in such a way that the current intensity and/or the potential on the output line are always set in such a way that the power consumption of the driver circuit lies in a lower power range of the current-voltage window prescribed by the specification. The power consumption of the output driver can thereby be reduced. Furthermore, the output driver can be controlled in this way such that it can also react to influences of the load applied to the output driver on the potential value of the output signal and always sets the current intensity or the potential on the output line such that it lies within the specification-conforming current-voltage window of the driver circuit. The control of the driver strength of the driver circuit may be carried out continuously, periodically or in accordance with a setting signal. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention is explained in more detail with reference to the accompanying drawings, in which: FIG. 1 shows a block diagram of an output driver according to one embodiment of the invention; and FIGS. 2a, 2b show minimum and maximum current-voltage characteristic curves for illustrating the current-voltage windows for the pull-down path and the pull-up path of the driver circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a block diagram of an output driver according to one embodiment of the invention. The output driver has a driver circuit 1 comprising a p-channel transistor 2 and an n-channel transistor 3. An input signal E is applied to control inputs of the p-channel transistor 2 and of the n-channel transistor 3, which input signal is driven in inverted fashion onto an output line 4 connected to an output 5 of the driver circuit 1. A first terminal of the p-channel transistor 2 is connected to a high supply potential. A second terminal of the p-channel transistor 2 is connected to a first terminal of the n-channel transistor 3, and a second terminal of the n-channel transistor 3 is connected to a low supply potential, e.g., a ground potential GND. The driver circuit 1 furthermore comprises a setting circuit 6, by means of which the driver strength of the driver circuit 1 can be set in accordance with a control signal S on a control line 7. The driver strength may be set, for example, by enlarging or decreasing the active area of the p-channel transistor 2 and of the n-channel transistor 3 in a manner dependent on the control signal S. Alternatively, a plurality of such circuits, each having a p-channel transistor and an n-channel transistor, may be connected in parallel to jointly drive an input signal present at the circuits' respective control inputs onto the output line 4. Other possibilities are also conceivable for providing a setting circuit 6 such that the driver strength of an output stage connected thereto can be set in a manner dependent on a control signal. The output line 4 of the driver circuit 1 is connected to a control unit 8. The control unit 8 is configured to evaluate the potential value on the output line 4 in accordance with predetermined reference values and to generate the control signal S utilized to drive the driver circuit 1. The control unit 8 is also configured to correspondingly adapt the driver strength of the driver circuit 1 if the potential of the respective output signal that is present on the output line lies above or below a range defined by reference potentials. In the exemplary embodiment illustrated, the control unit 8 includes a comparator unit 12 comprising a first comparator 13 and a second comparator 14. A first reference potential VRef1 provided by a multiplexer 11 is applied to the first comparator 13 and a second reference potential VRef2 is applied to the second comparator 14. The first and second reference potentials VRef1, VRef2 define a potential range within which the potential on the output line 4 is intended to lie. Outputs of the first comparator 13 and of the second comparator 14 are connected to an evaluation unit 9, which generates the control signal S at an output and makes it available to the setting circuit 6 of the driver circuit 1. If the potential on the output line 4 lies above the potential prescribed by the first reference potential value VRef1, then the evaluation unit 9 generates a control signal that specifies to the driver circuit 1 that the driver strength be reduced. If the potential value on the output line 4 is less than the second reference potential value VRef2, then the evaluation unit 9 generates a control signal that indicates to the driver circuit 1 that the driver strength be increased. In this way, the potential value on the output line 4 can be regulated to a driver strength which enables the potential value on the output line 4 to be put into a potential window defined by the first reference potential value VRef1 and the second reference potential value VRef2. Since the potential value on the output line 4 depends on the input signal E present, the input line connected to the input of the driver circuit 1 is connected via a connecting line 15 to the control unit 8, in particular to the multiplexer 11. In this way, the multiplexer 11 may apply the first and second reference potential values VRef1, VRef2 to the comparator unit 12 in such a way that corresponding selected reference potential values are specified depending on the signal level of the output signal to be output on the output line 4. For this purpose, essentially four reference potentials may be prescribed for the multiplexer 11, two respectively prescribing the desired potential value range for a high level and the respective other two reference potentials prescribing the potential value range for the low level of the output signal. The reference potentials may be provided by a voltage divider 10, for example, to which a reference supply voltage VRef or a reference supply current IRef is applied. The reference potentials for defining the potential window for the high level of the output signal are chosen such that they lie within a lower range of the potential window permitted by the specification for the high level of the output signal on the output line 4. The potential window for the low level of the output signal on the output line 4 is defined by the reference potentials such that it likewise lies within a lower range of the potential window prescribed by the specification for the low level of the output signal. The evaluation unit 9 may be designed as a counter, for example, wherein the control signal is transmitted to the setting circuit 6 as a digital value of the counter reading or wherein the counter value is converted into an analog voltage signal which is provided to the setting circuit 6 as a control signal. The first comparator 13 and the second comparator 14 are configured in such a way that, at the output of the first comparator 13, a logic “1” is present if the potential on the output line 4 exceeds the first reference potential VRef, and a logic “0” is present if the potential on the output line 4 falls below the first reference potential VRef1. Equally, at the output of the second comparator 14, a logic “1” is present if the potential on the output line 4 falls below the second reference potential VRef2 and a logic “0” is present if the potential on the output line 4 exceeds the second reference potential VRef2. The counter in the evaluation unit 9 is decremented if a logic “1” is present at the output of the first comparator 13, and incremented if a logic “1” is present at the output of the second comparator 14. If a logic “0” is present at both outputs of the comparators 13, 14, then the counter reading of the counter in the evaluation unit 9 is not altered. The first and second reference voltages are prescribed such that the range formed by the first and second reference voltages VRef1, VRef2 lies within a lower range of the permitted potential window prescribed by the specification. The reference voltages VRef1, VRef2 are selected by the multiplexer 11 depending on whether a high level or a low level is intended to be output at the output 5 of the driver circuit 1. For this purpose, by way of example, the input signal may be connected to the multiplexer 11. Alternatively, the output signal on the output line 4 may be connected to the multiplexer 11. By means of the voltage divider 10, reference voltages are made available such that, in each case, two of the reference voltages may be selected by means of the multiplexer 11 to define a voltage range which determines a lower power range within the permissible current-voltage window for the output signal on the output line. As an alternative, instead of the potential on the output line, a current may also be converted into a measurement voltage, e.g., with the aid of a measuring resistor or another current measuring method, and the measurement voltage may then be compared with the reference potentials made available. It is also possible for the two setting methods to be combined with one another in that both the potential and the current intensity on the output line 4 are measured and evaluated either by two separate comparator circuits or successively with the aid of the reference potentials made available. FIGS. 2a and 2b show the switching behaviors of the n-channel transistor 3 in the pull-down path and of the p-channel transistor 2 of the driver circuit 1 in the pull-up path. The current-voltage characteristic curves define a range that is permissible in accordance with the specification. The permissible potential ranges for the high and low levels on the output line are thereby determined. The range is defined in accordance with the lower current-voltage characteristic curve, identified by Imin, and the upper current-voltage characteristic curve, identified by Imax. The current-voltage characteristic curves identified by Inom,max and Inom,min represent nominal values of the respective transistor 2, 3. The driver power is principally determined by the current driver capability of the n-channel and p-channel transistors. In accordance with the specification, an output current may be provided in the current-voltage window defined by the lower and upper current-voltage characteristic curves. The less current flows on the output line, however, the lower the power consumption of the driver circuit 1. A reduction of the power consumption through a reduction of the current intensity through the activated transistor is permissible as long as the current intensity is within the respective current-voltage window prescribed by the specification. It is thus possible, within the limits prescribed by the specification, to define a current intensity range which brings about minimal power consumption through the driver circuit 1. This range is chosen to lie within the range prescribed by the current-voltage windows. The range may be defined, for example, in that a tolerance magnitude is added to the minimum current intensity Imin prescribed for a state of the output signal in accordance with the lower current-voltage characteristic curve, and the corresponding lower power range is thereby defined. Equally, provision may be made for providing a certain distance between the lower power range and the minimum current intensity value, so that the lower current/voltage characteristic curve is not undershot during regulation. The adaptation of the driver strength of the driver circuit 1 may take place continuously or at periodic time intervals. It is expedient for the setting of the driver strength not to be carried out continuously, since the control unit 8 also has a power consumption which might minimize or cancel the power saving. The driver strength may also be adapted in accordance with an adaptation signal at predetermined points in time. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to an output driver for an integrated circuit having a driver circuit for driving an input signal onto an output line. The invention furthermore relates to a method for driving an output driver for an integrated circuit. 2. Description of the Related Art Integrated circuits usually have output drivers for driving signals which have been generated in circuits of the integrated circuit on external lines connected to the integrated circuit. To define the driver behavior of the output drivers, a specification is provided which, depending on the output driver, provides an upper and a lower current value or an upper and lower potential value depending on the signal state (high level or low level) of the output signal to be driven. In this case, the specification respectively specifies an upper and lower current-voltage characteristic curve for the activated pull-up path of the driver circuit and for the pull-down path of the driver circuit, which characteristic curve in each case defines a current intensity range within which the current intensity through the relevant path and thus through the output line must be. Depending on whether a high or low level is intended to be driven by the output driver, the specification prescribes different upper and lower current-voltage characteristic curves for the pull-up path and the pull-down path. Usually, the specifications for integrated circuits, in particular for SDRAM and DDR memory circuits, provide a relatively large current intensity range or potential range for the output drivers, so that it is simpler to achieve the specification-conforming current intensity values or potential values for process cut-off values, temperatures and voltages (PVT). The specification-conforming current intensity ranges or voltage ranges of the pull-up paths and pull-down paths may signify great differences with regard to the power consumption depending on the position of the actual potential value or current value within the specification, since more power is required in an upper current intensity range and/or in an upper potential range than if the output signal is in a lower range of the permissible predetermined potential window and/or current intensity window. However, the exact potential value or current value with which the signal is driven with the aid of the output driver cannot be established from the outset since it is necessary to take account of process deviations, temperature fluctuations and voltage fluctuations which might have the effect that the relevant value is outside the specification-conforming window. Moreover, different loads are possible at the outputs of the integrated circuit, so that this may result in different potential values or current values depending on the connected components or the switching states thereof. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide an integrated circuit and a method for controlling an output driver which are able to reduce the power consumption of the integrated circuit and to ensure that the corresponding potential value or current value at the output of the output driver is within the specification. A first aspect of the present invention provides an output driver for an integrated circuit. The output driver has a driver circuit for driving an input signal onto an output line. The driver circuit is dimensioned in such a way as to supply a current intensity dependent on the input signal to be driven and/or a potential dependent on the input signal to be driven on the output line. The current value and/or the potential value lie in a current intensity range and/or potential range defined by a predetermined specification. The driver strength of the driver circuit may be set in accordance with a control signal. A measuring circuit is provided to measure the current intensity of the current flowing on the output line and/or the potential of the output line. A control circuit serves for setting the driver strength of the driver circuit so that the potential on the output line is set to a potential value and/or the current intensity is set to a current value, wherein the set potential value and the set current value may lie in a lower power range of the current intensity range and/or potential range prescribed by the specification. In this way, one aspect of the invention provides an output driver for an integrated circuit which makes it possible to set the current value and/or the potential value on the output line in a lower power range, i.e., to operate the integrated circuit at an operating point at which the power consumption of the output driver can be reduced, but without permitting a current value or potential value outside the specification-conforming limits. The current intensity ranges and/or potential ranges permissible in accordance with the specification are comparatively large on account of process fluctuations in the production of the integrated circuits, a high operating temperature range in which the integrated circuit can be operated reliably, and voltage fluctuations that may occur. It follows from this that the output driver has a different power consumption depending on the current intensity or potential within the permissible windows with which the output driver drives a signal onto the output line. Consequently, the range of possible power consumptions is likewise very large on account of the large range of values for the potential and the current intensity. In order not to reach an operating range outside the specification on account of temperature fluctuations, process fluctuations or the like, the driver strength of the output driver may be set by means of the production process such that the input signal to be driven is driven with a current intensity and a potential which essentially lies centrally within the current intensity range or potential range prescribed by the specification. One aspect of the invention also provides a control circuit which influences the driver strength of the driver circuit. The driver strength of the driver circuit may be set by the control circuit in such a way that the current intensity and/or the potential on the output line, depending on the input signal to be driven, lies in a lower power range of the current intensity range and/or potential range prescribed by the specification, i.e., the power consumption of the output driver is reduced within the permissible range. As a result, it is possible to take into account the process fluctuations during the production of the integrated circuit, the respective operating temperature, the potential fluctuations, e.g., of the supply voltages, and the load connected to the output driver such that the driver circuit of the output driver supplies a potential value and a current intensity value lying within the specification-conforming range limits, albeit in a lower power range to reduce the power consumption of the output driver in comparison with the energy consumption of a noncontrolled driver circuit. One aspect of the invention provides that the lower power range is determined by a lower current limit value prescribed by the specification and a lower current limit value increased by a tolerance magnitude and/or by a lower potential value prescribed by the specification and a lower potential value increased by a tolerance magnitude. In this way, a lower power range can be defined in the current or potential value prescribed by the specification. The specification may specify a first maximum and minimum current-voltage characteristic curve for a pull-up path of the driver circuit and a second maximum and minimum current-voltage characteristic curve for a pull-down path of the driver circuit. Depending on the respectively driven pull-up path or pull-down path of the driver circuit, the lower power range is determined depending on the current intensity range which is prescribed by the specification and is specified by the first or second current-voltage characteristic curve. The control circuit may comprise a comparator device for comparing the measured current value or the measured potential value with a reference current value or a reference potential value dependent on the specification. The reference current value or the reference potential value may be provided by a reference voltage source or a reference current source. A further aspect of the present invention provides a method for driving an output driver for an integrated circuit having a driver circuit. The driver circuit serves for driving an output signal dependent on an input signal with a current intensity and/or a potential onto an output line. The current intensity of the current flowing on the output line and/or the potential on the output line are measured. The driver strength of the driver circuit is controlled in such a way as to set the current intensity and/or the potential in a current intensity range and/or potential range defined by a predetermined specification. Furthermore, the driver strength is set in such a way that the potential value and/or the current intensity lie in a lower power range of the current intensity range and potential range prescribed by the specification. The method according to the invention affords the possibility of setting the driver power of an output driver in such a way that the current intensity and/or the potential on the output line are always set in such a way that the power consumption of the driver circuit lies in a lower power range of the current-voltage window prescribed by the specification. The power consumption of the output driver can thereby be reduced. Furthermore, the output driver can be controlled in this way such that it can also react to influences of the load applied to the output driver on the potential value of the output signal and always sets the current intensity or the potential on the output line such that it lies within the specification-conforming current-voltage window of the driver circuit. The control of the driver strength of the driver circuit may be carried out continuously, periodically or in accordance with a setting signal. | 20040709 | 20061205 | 20050210 | 69859.0 | 1 | TON, MY TRANG | OUTPUT DRIVER FOR AN INTEGRATED CIRCUIT AND METHOD FOR DRIVING AN OUTPUT DRIVER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,888,089 | ACCEPTED | Immunomodulatory oligonucleotides | Oligonucleotides containing unthylated CpG dinucleotides and therapeutic utilities based on their ability to stimulate an immune response in a subject are disclosed. Also disclosed are therapies for treating diseases associated with immune system activation that are initiated by unthylated CpG dinucleotides in a subject comprising administering to the subject oligonucleotides that do not contain unmethylated CpG sequences (i.e. methylated CpG sequences or no CpG sequence) to outcompete unmethylated CpG nucleic acids for binding. Further disclosed are methylated CpG containing dinucleotides for use antisense therapies or as in vivo hybridization probes, and immunoinhibitory oligonucleotides for use as antiviral therapeutics. | 1-36. (Canceled). 37. A method of increasing interferon-gamma in a subject comprising administering to a subject an immunostimulatory oligonucleotide/delivery complex, said complex comprising an immunostimulatory oligonucleotide linked to a biodegradable delivery complex, wherein the immunostimulatory oligonucleotide comprises the sequence 5′-C, G-3′ and wherein said delivery complex is less than 10 μm in size, in an amount sufficient to modulate an immune response in said subject. 38. The method of claim 37, wherein said delivery complex is a liquid phase microcarrier. 39. The method of claim 37, wherein said immunostimulatory oligonucleotide is covalently linked to said delivery complex. 40. The method of claim 37, wherein said immunostimulatory oligonucleotide is non-covalently linked to said delivery complex. 41. The method of claim 37, wherein said immunostimulatory oligonucleotide comprises a phosphate backbone modification. 42. The method of claim 41, wherein said phosphate backbone modification is a phosphorothioate. 43. The method of claim 37, wherein the immunostimulatory oligonucleotide is 8 to 40 nucleotides in length and comprises: 5′X1X2CGX3X43′, wherein C and G are unmethylated and X1, X2, X3, and X4 are nucleotides. 44. The method of claim 43, wherein the immunostimulatory oligonucleotide does not include a GCG trinucleotide at a 5′ and/or 3′ terminal. 45. The method of claim 43 wherein the immunostimulatory oligonucleotide does not contain a 5′X1X2CGX3X43′ palindrome. 46. The method of claim 44 wherein the immunostimulatory oligonucleotide does not contain a 5′X1X2CGX3X43′ palindrome. | GOVERNMENT SUPPORT The work resulting in this invention was supported in part by National Institute of Health Grant No. R29-AR42556-01. The U.S. Government may therefore be entitled to certain rights in the invention. BACKGROUND OF THE INVENTION DNA Binds to Cell Membrane and is Internalized In the 1970's, several investigators reported the binding of high molecular weight DNA to cell membranes (Lerner, R. A., W. Meinke, and D. A. Goldstein. 1971. “Membrane-associated DNA in the cytoplasm of diploid human lymphocytes”. Proc. Natl. Acad. Sci. USA 68:1212; Agrawal, S. K, R. W. Wagner, P. K. McAllister, and B. Rosenberg. 1975. “Cell-surface-associated nucleic acid in tumorigenic cells made visible with platinum-pyrimidine complexes by electron microscopy”. Proc. Nat. Acad. Sci. USA 72:928). In 1985 Bennett et al. presented the first evidence that DNA binding to lymphocytes is similar to a ligand receptor interaction: binding is saturable, competitive, and leads to DNA endocytosis and degradation (Bennett, R. M., G. T. Gabor, and M. M. Merritt, 1985. “DNA binding to human leukocytes. Evidence for a receptor-mediated association, internalization, and degradation of DNA”. J Clin. Invest. 76:2182). Like DNA, oligodeoxyribonucleotides (ODNs) are able to enter cells in a saturable, sequence independent, and temperature and energy dependent fashion (reviewed in Jaroszewski, J. W., and J. S. Cohen. 1991. “Cellular uptake of antisense oligodeoxynucleotides”. Advanced Drug Delivery Reviews 6:235; Akhtar, S., Y. Shoji, and R. L. Juliano. 1992. “Pharmaceutical aspects of the biological stability and membrane transport characteristics of antisense oligonucleotides”. In: Gene Regulation: Biology of Antisense RNA and DNA. R. P. Erickson, and J. G. Izant, eds. Raven Press, Ltd. New York, pp. 133; and Zhao, Q., T. Waldschimdt, E. Fisher, C. J. Herrera, and A. M. Krieg., 1994. “Stage specific oligonucleotide uptake in murine bone marrow B cell precursors”. Blood, 84:3660). No receptor for DNA or ODN uptake has yet been cloned, and it is not yet clear whether ODN binding and cell uptake occurs through the same or a different mechanism from that of high molecular weight DNA. Lymphocyte ODN uptake has been shown to be regulated by cell activation. Spleen cells stimulated with the B cell mitogen LPS had dramatically enhanced ODN uptake in the B cell population, while spleen cells treated with the T cell mitogen Con A showed enhanced ODN uptake by T but not B cells (Krieg, A. M., F. Grnelig-Meyling, M. F. Gourley, W. J. Kisch, L. A. Chrisey, and A. D. Steinberg. 1991. “Uptake of oligodeoxyribonucleotides by lymphoid cells is heterogeneous and inducible”. Antisense Research and Development 1:161). Immune Effects of Nucleic Acids Several polynucleotides have been extensively evaluated as biological response modifiers. Perhaps the best example is poly (I,C) which is a potent inducer of IFN production as well as a macrophage activator and inducer of NK activity (Talmadge, J. E., J. Adams, H. Phillips, M. Collins, B. Lenz, M. Schneider, E. Schlick, R. Ruffmann, R. H. Wiltrout, and M. A. Chirigos. 1985. “Immunomodulatory effects in mice of polyinosinic-polycytidylic acid complexed with poly-L:-lysine and carboxymethylcellulose”. Cancer Res. 45:1058; Wiltrout, R. H., R. R. Salup, T. A. Twilley, and J. E. Talmadge. 1985. “Immunomodulation of natural killer activity by polyribonucleotides”. J. Biol. Resp. Mod 4:512; Krown, S. E. 1986. “Interferons and interferon inducers in cancer treatment”. Sem. Oncol. 13:207; and Ewel, C. H., S. J. Urba, W. C. Kopp, J. W. Smith II, PG. Steis, J. L. Rossio, D. L. Longo, M. J. Jones, W. G. Alvord, C. M. Pinsky, J. M. Beveridge, K. L. McNitt, and S. P. Creekmore. 1992. “Polyinosinic-polycytidylic acid complexed with poly-L-lysine and carboxymethylcellulose in combination with interleukin 2 in patients with cancer: clinical and immunological effects”. Canc. Res. 52:3005). It appears that this murine NK activation may be due solely to induction of IFN β secretion (Ishikawa, R., and C. A. Biron. 1993. “IFN induction and associated changes in splenic leukocyte distribution”. J. Immunol. 150:3713). This activation was specific for the ribose sugar since deoxyribose was ineffective. Its potent in vitro antitumor activity led to several clinical trials using poly (I,C) complexed with poly-L-lysine and carboxymethylcellulose (to reduce degradation by RNAse) (Talmadge, J. E., et al., 1985. cited supra; Wiltrout, R. H., et al., 1985. cited supra); Krown, S. E., 1986. cited supra); and Ewel, C. H., et al. 1992. cited supra). Unfortunately, toxic side effects have thus far prevented poly (I,C) from becoming a useful therapeutic agent. Guanine ribonucleotides substituted at the C8 position with either a bromine or a thiol group are B cell mitogens and may replace “B cell differentiation factors” (Feldbush, T. L., and Z. K. Ballas. 1985. “Lymphokine-like activity of 8-mercaptoguanosine: induction of T and B cell differentiation”. J. Immunol. 134:3204; and Goodman, M. G. 1986. “Mechanism of synergy between T cell signals and C8-substituted guanine nucleosides in humoral immunity: B lymphotropic cytokines induce responsiveness to 8-mercaptoguanosine”. J. Immunol. 136:3335). 8-mercaptoguanosine and 8-bromoguanosine also can substitute for the cytokine requirement for the generation of MHC restricted CT1 (Feldbush, T. L., 1985. cited supra), augment murine NK activity (Koo, G. C., M. E. Jewell, C. L. Manyak, N. H. Sigal, and L. S. Wicker. 1988. “Activation of murine natural killer cells and macrophages by 8-bromoguanosine”. J. Immunol. 140:3249), and synergize with IL-2 in inducing murine LAK generation (Thompson, R. A., and Z. K. Ballas. 1990. “Lymphokine-activated killer (LAK) cells. V. 8-Mercaptoguanosine as an IL-2-sparing agent in LAK generation”. J. Immunol. 145:3524). The NK and LAK augmenting activities of these C8-substituted guanosines appear to be due to their induction of IFN (Thompson, R. A., et al. 1990. cited supra). Recently, a 5′ triphosphorylated thymidine produced by a mycobacterium was found to be mitogenic for a subset of human γδ T cells (Constant, P., F. Davodeau, M. -A. Peyrat, Y. Poquet, G. Puzo, M. Bonneville, and J. -J. Fournie. 1994. “Stimulation of human γε T cells by nonpeptidic mycobacterial ligands” Science 264:267). This report indicated the possibility that the immune system may have evolved ways to preferentially respond to microbial nucleic acids. Several observations suggest that certain DNA structures may also have the potential to activate lymphocytes. For example, Bell et al. reported that nucleosomal protein-DNA complexes (but not naked DNA) in spleen cell supernatants caused B cell proliferation and immunoglobulin secretion (Bell, D. A., B. Morrison, and P. VandenBygaart. 1990. “Immunogenic DNA-related factors”. J. Clin. Invest. 85:1487). In other cases, naked DNA has been reported to have immune effects. For example, Messina et al. have recently reported that 260 to 800 bp fragments of poly (dG)•(dC) and poly (dG•dC) were mitogenic for B cells (Messina, J. P., G. S. Gilkeson, and D. S. Pisetsky. 1993. “The influence of DNA structure on the in vitro stimulation of murine lymphocytes by natural and synthetic polynucleotide antigens”. Cell. Immunol. 147:148). Tokunaga, et al. have reported that dGe dC induces γ-IFN and NK activity (Tokunaga, S. Yamamoto, and K Namba. 1988. “A synthetic single-stranded DNA, poly(dG,dC), induces interferon-α/β and -γ, augments natural killer activity, and suppresses tumor growth” Jpn. J Cancer Res. 79:682). Aside from such artificial homopolymer sequences, Pisetsky et al. reported that pure mammalian DNA has no detectable immune effects, but that DNA from certain bacteria induces B cell activation and immunoglobulin secretion (Messina, J. P., G. S. Gilkeson, and D. S. Pisetsky. 1991. “Stimulation of in vitro murine lymphocyte proliferation by bacterial DNA”. J. Immunol. 147:1759). Assuming that these data did not result from some unusual contaminant, these studies suggested that a particular structure or other characteristic of bacterial DNA renders it capable of triggering B cell activation. Investigations of mycobacterial DNA sequences have demonstrated that ODN which contain certain palindrome sequences can activate NK cells (Yanamoto, S., T. Yamamoto, T. Kataoka, E. Kuramoto, O. Yano, and T. Tokunaga. 1992. “Unique palindromic sequences in synthetic oligonucleotides are required to induce INF and augment INF-mediated natural killer activity”. J. Immunol. 148:4072; Kuramoto, E., O. Yano, Y. Kimura, M. Baba, T. Makino, S. Yamamoto, T. Yamamoto, T. Kataoka, and T. Tokunaga 1992. “Oligonucleotide sequences required for natural killer cell activation”. Jpn. J Cancer Res. 83:1128). Several phosphorothioate modified ODN have been reported to induce in vitro or in vivo B cell stimulation (Tanaka, T., C. C. Chu, and W. E. Paul. 1992. “An antisense oligonucleotide complementary to a sequence in Iγ2b increases γ2b germline transcripts, stimulates B cell DNA synthesis, and inhibits immunoglobulin secretion”. J. Exp. Med 175:597; Branda, R. F., A. L. Moore, L. Mathews, J. J. McCormack, and G. Zon. 1993. “Immune stimulation by an antisense oligomer complementary to the rev gene of HIV-1”. Biochem. Pharmacol. 45:2037; McIntyre, K. W., K Lombard-Gillooly, J. R Perez, C. Kunsch, U. M. Sarmiento, J. D. Larigan, K. T. Landreth, and R Narayanarn 1993. “A sense phosphorothioate oligonucleotide directed to the initiation codon of transcription factor NF-κ β T65 causes sequence-specific immune stimulation”. Antisense Res. Develop. 3:309; and Pisetsky, D. S., and C. F. Reich 1993. “Stimulation of murine lymphocyte proliferation by a phosphorothioate oligonucleotide with antisense activity for herpes simplex virus”. Life Sciences 54:101). These reports do not suggest a common structural motif or sequence element in these ODN that might explain their effects. The CREB/ATF Family of Transcription Factors and their Role in Replication The cAMP response element binding protein (CREB) and activating transcription factor (ATF) or CREB/ATF family of transcription factors is a ubiquitously expressed class of transcription factors of which 11 members have so far been cloned (reviewed in de Groot, R. P., and P. Sassone-Corsi: “Hormonal control of gene expression: Multiplicity and versatility of cyclic adenosine 3′,5′-monophosphate-responsive nuclear regulators”. Mol. Endocrin. 7:145, 1993; Lee, K. A. W., and N. Masson: “Transcriptional regulation by CREB and its relatives”. Biochim Biophys. Acta 1174:221, 1993.). They all belong to the basic region/leucine zipper (bZip) class of proteins. All cells appear to express one or more CREB/ATF proteins, but the members expressed and the regulation of mRNA splicing appear to be tissue-specific. Differential splicing of activation domains can determine whether a particular CREB/ATF protein will be a transcriptional inhibitor or activator. Many CREB/ATF proteins activate viral transcription, but some splicing variants which lack the activation domain are inhibitory. CREB/ATF proteins can bind DNA as homo- or hetero- dimers through the cAMP response element, the CRE, the consensus form of which is the unmethylated sequence TGACGTC (binding is abolished if the CpG is methylated) (Iguchi-Ariga, S. M. M., and W. Schaffner: “CpG methylation of the cAMP-responsive enhancer/promoter sequence TGACGTCA abolishes specific factor binding as well as transcriptional activation”. Genes & Develop. 3:612, 1989.). The transcriptional activity of the CRE is increased during B cell activation (Xie, H. T. C. Chiles, and T. L. Rothstein: “Induction of CREB activity via the surface Ig receptor of B cells”. J. Immunol. 151:880, 1993.). CREB/ATF proteins appear to regulate the expression of multiple genes through the CRE including immunologically important genes such as fos, jun B, Rb-1, IL-6, IL-1 (Tsukada, J., K. Saito, W. R. Waterman, A. C. Webb, and P. E. Auron: “Transcription factors NF-IL6 and CREB recognize a common essential site in the human prointerleukin 1β gene”. Mol. Cell. Biol. 14:7285, 1994; Gray, G. D., O. M. Hernandez, D. Hebel, M. Root, J. M. Pow-Sang, and E. Wickstrom: “Antisense DNA inhibition of tumor growth induced by c-Ha-ras oncogene in nude mice”. Cancer Res. 53:577, 1993), IFN-β (Du, W., and T. Maniatis: “An ATF/CREB binding site protein is required for virus induction of the human interferon B gene”. Proc. Natl. Acad. Sci. USA 89:2150, 1992), TGF-β1(Asiedu, C. K., L. Scott, R. K. Assoian, M. Ehrlich: “Binding of AP-1/CREB proteins and of MDBP to contiguous sites downstream of the human TGF-B 1 gene”. Biochim. Biophys. Acta 1219:55, 1994.), TGF-β2, class II MHC (Cox, P. M., and C. R. Goding: “An ATF/CREB binding motif is required for aberrant constitutive expression of the MHC class II DRa promoter and activation by SV40 T-antigen”. Nucl. Acids Res. 20:4881, 1992.), E-selectin, GM-CSF, CD-8α, the germline Igα constant region gene, the TCR Vβ gene, and the proliferating cell nuclear antigen (Huang, D., P. M. Shipman-Appasamy, D. J. Orten, S. H. Hinrichs, and M. B. Prystowsky: “Promoter activity of the proliferating-cell nuclear antigen gene is associated with inducible CRE-binding proteins in interleukin 2-stimulated T lymphocytes”. Mol. Cell. Biol. 14:4233, 1994.). In addition to activation through the cAMP pathway, CREB can also mediate transcriptional responses to changes in intracellular Ca++ concentration (Sheng, M., G. McFadden, and M. E. Greenberg: “Membrane depolarization and calcium induce c-fos transcription via phosphorylation of transcription factor CREB”. Neuron 4:571, 1990). The role of protein-protein interactions in transcriptional activation by CREB/ATF proteins appears to be extremely important. Activation of CREB through the cyclic AMP pathway requires protein kinase A (PKA), which phosphorylates CREB341 on ser133 and allows it to bind to a recently cloned protein, CBP (Kwok, R. P. S., J. R. Lundblad, J. C. Chrivia, J. P. Richards, H. P. Bachinger, R. G. Brennan, S. G. E. Roberts, M. R Green, and R. H. Goodman: “Nuclear protein CBP is a coactivator for the transcription factor CREB”. Nature 370:223, 1994; Arias, J., A. S. Alberts, P. Brindle, F. X. Claret, T. Smea, M. Karin, J. Feramisco, and M. Montminy: “Activation of cAMP and mitogen responsive genes relies on a common nuclear factor”. Nature 370:226, 1994.). CBP in turn interacts with the basal transcription factor TFIIB causing increased transcription. CREB also has been reported to interact with dTAFII 110, a TATA binding protein-associated factor whose binding may regulate transcription (Ferreri, K., G. Gill, and M. Montminy: “The cAMP-regulated transcription factor CREB interacts with a component of the TFIID complex”. Proc. Natl. Acad. Sci. USA 91:1210, 1994.). In addition to these interactions, CREB/ATF proteins can specifically bind multiple other nuclear factors (Hoeffler, J. P., J. W. Lustbader, and C. -Y. Chen: “Identification of multiple nuclear factors that interact with cyclic adenosine 3′,5′-monophosphate response element-binding protein and activating transcription factor-2 by protein-protein interactions”. Mol. Endocrinol. 5:256, 1991) but the biologic significance of most of these interactions is unknown. CREB is normally thought to bind DNA either as a homodimer or as a heterodimer with several other proteins. Surprisingly, CREB monomers constitutively activate transcription (Krajewski, W., and K. A. W. Lee: “A monomeric derivative of the cellular transcription factor CREB functions as a constitutive activator”. Mol. Cell Biol. 14:7204, 1994.). Aside from their critical role in regulating cellular transcription, it has recently been shown that CREB/ATF proteins are subverted by some infectious viruses and retroviruses, which require them for viral replication. For example, the cytomegalovirus immediate early promoter, one of the strongest known mammalian promoters, contains eleven copies of the CRE which are essential for promoter function (Chang, Y. -N., S. Crawford, J. Stall, D. R Rawlins, K. -T. Jeang, and G. S. Hayward: “The palindromic series I repeats in the simian cytomegalovirus major immediate-early promoter behave as both strong basal enhancers and cyclic AMP response elements”. J. Virol. 64:264, 1990). At least some of the transcriptional activating effects of the adenovirus E1A protein, which induces many promoters, are due to its binding to the DNA binding domain of the CREB/ATF protein, ATF-2, which mediates E1A inducible transcription activation (Liu, F., and M. P Green: “Promoter targeting by adenovirus E1a through interaction with different cellular DNA-binding domains”. Nature 368:520, 1994). It has also been suggested that E1A binds to the CREB-binding protein, CBP (Arany, Z., W. R. Sellers, D. M. Livingston, and R. Eckner: “E1A-associated p300 and CREB-associated CBP belong to a conserved family of coactivators”. Cell 77:799, 1994). Human T lymphotropic virus-I (HTLV-1), the retrovirus which causes human T cell leukemia and tropical spastic paresis, also requires CREB/ATF proteins for replication. In this case, the retrovirus produces a protein, Tax, which binds to CREB/ATF proteins and redirects them from their normal cellular binding sites to different DNA sequences (flanked by G- and C-rich sequences) present within the HTLV transcriptional enhancer (Paca-Uccaralertkun, S., L. -J. Zhao, N. Adya, J. V. Cross, B. R Cullen, I. M. Boros, and C.-Z. Giam: “In vitro selection of DNA elements highly responsive to the human T-cell lymphotropic virus type I transcriptional activator, Tax”. Mol. Cell. Biol. 14:456, 1994; Adya, N., L. -J. Zhao, W. Huang, I. Boros, and C. -Z. Giam: “Expansion of CREB's DNA recognition specificity by Tax results from interaction with Ala-Ala-Arg at positions 282-284 near the conserved DNA-binding domain of CREB”. Proc. Natl. Acad. Sci. USA 91:5642, 1994). SUMMARY OF THE INVENTION The instant invention is based on the finding that certain oligonucleotides containing unmethylated cytosine-guanine (CpG) dinucleotides activate lymphocytes as evidenced by in vitro and in vivo data. Based on this finding, the invention features, in one aspect, novel immunostimulatory oligonucleotide compositions. In a preferred embodiment, an immunostimulatory oligonucleotide is synthetic, between 2 to 100 base pairs in size and contains a consensus mitogenic CpG motif represented by the formula: 5′X1X2CGX3X4 3′ wherein C and G are unmethylated, X1, X2, X3 and X4 are nucleotides and a GCG trinucleotide sequence is not present at or near the 5′ and 3′ termini. For facilitating uptake into cells, CpG containing immunostimulatory oligonucleotides are preferably in the range of 8 to 40 base pairs in size. Prolonged immunostimulation can be obtained using stabilized oligonucleotides, particularly phosphorothioate stabilized oligonucleotides. Enhanced immunostimulatory activity has been observed where X1X2 is the dinucleotide GpA and/or X3X4 is the dinucleotide is most preferably TpC or also TpT. Further enhanced immunostimulatory activity has been observed where the consensus motif X1X2CGX3X4 is preceded on the 5′ end by a T. In a second aspect, the invention features useful methods, which are based on the immunostimulatory activity of the oligonucleotides. For example, lymphocytes can either be obtained from a subject and stimulated ex vivo upon contact with an appropriate oligonucleotide; or a non-methylated CpG containing oligonucleotide can be administered to a subject to facilitate in vivo activation of a subject's lymphocytes. Activated lymphocytes, stimulated by the methods described herein (e.g. either ex vivo or in vivo), can boost a subject's immune response. The immunostimulatory oligonucleotides can therefore be used to treat, prevent or ameliorate an immune system deficiency (e.g., a tumor or cancer or a viral, fungal, bacterial or parasitic infection in a subject. In addition, immunostimulatory oligonucleotides can also be administered as a vaccine adjuvant, to stimulate a subject's response to a vaccine. Further, the ability of immunostimulatory cells to induce leukemic cells to enter the cell cycle, suggests a utility for treating leukemia by increasing the sensitivity of chronic leukemia cells and then administering conventional ablative chemotherapy. In a third aspect, the invention features neutral oligonucleotides (i.e. oligonucleotide that do not contain an unmethylated CpG or which contain a methylated CpG dinucleotide). In a preferred embodiment, a neutralizing oligonucleotide is complementary to an immunostimulatory sequence, but contains a methylated instead of an unmethylated CpG dinucleotide sequence and therefore can compete for binding with unmethylated CpG containing oligonucleotides. In a preferred embodiment, the methylation occurs at one or more of the four carbons and two nitrogens comprising the cytosine six member ring or at one or more of the five carbons and four nitrogens comprising the guanine nine member double ring. 5′ methyl cytosine is a preferred methylated CpG. In a fourth aspect, the invention features useful methods using the neutral oligonucleotides. For example, in vivo administration of neutral oligonucleotides should prove useful for treating diseases such as systemic lupus erythematosus, sepsis and autoimmune diseases, which are caused or exacerbated by the presence of unmethylated CpG dimers in a subject In addition, methylation CpG containing antisense oligonucleotides or oligonucleotide probes would not initiate an immune reaction when administered to a subject in vivo and therefore would be safer than corresponding unmethylated oligonucleotides. In a fifth aspect, the invention features immunoinhibitory oligonucleotides, which are capable of interfering with the activity of viral or cellular transcription factors. In a preferred embodiment, immunoinhibitory oligonucleotides are between 2to 100 base pairs in size and contain a consensus immunoinhibitory CpG motif represented by the formula: 5′GCGXnGCG3′ wherein X=a nucleotide and n=in the range of 0-50. In a preferred embodiment, X is a pyrimidine. For facilitating uptake into cells, immunoinhibitory oligonucleotides are preferably in the range of 8 to 40 base pairs in size. Prolonged immunostimulation can be obtained using stabilized oligonucleotides, particularly phosphorothioate stabilized oligonucleotides. In a sixth and final aspect, the invention features various uses for immunoinhibitory oligonucleotides. Immunoinhibitory oligonucleotides have antiviral activity, independent of any antisense effect due to complementarity between the oligonucleotide and the viral sequence being targeted. Other features and advantages of the invention will become more apparent from the following detailed description and claims. DETAILED DESCRIPTION OF THE INVENTION Definitions As used herein, the following terms and phrases shall have the meanings set forth below: An “oligonucleotide” or “oligo” shall mean multiple nucleotides (i.e. molecules comprising a sugar (e.g. ribose or deoxyribose) linked to a phosphate group and to an exchangeable organic base, which is either a substituted pyrimidine (e.g. cytosine (C), thymine (T) or uracil (U)) or a substituted purine (e.g. adenine (A) or guanine (G)). The term “oligonucleotide” as used herein refers to both oligoribonucleotides (ORNs) and oligodeoxyribonucleotides (ODNs). The term. “oligonucleotide” shall also include oligonucleosides (i.e. an oligonucleotide minus the phosphate) and any other organic base containing polymer. Oligonucleotides can be obtained from existing nucleic acid sources (e.g. genomic or cDNA), but are preferably synthetic (e.g. produced by oligonucleotide synthesis). A “stabilized oligonucledtide” shall mean an oligonucleotide that is relatively resistant to in vivo degradation (e.g. via an exo- or endo-nuclease). Preferred stabilized oligonucleotides of the instant invention have a modified phosphate backbone. Especially preferred oligonucleotides have a phosphorothioate modified phosphate backbone (i.e. at least one of the phosphate oxygens is replaced by sulfur). Other stabilized oligonucleotides include: nonionic DNA analogs, such as akyl- and aryl- phosphonates (in which the charged phosphonate oxygen is replaced by an alkyl or aryl group), phosphodiester and alkylphosphotriesters, in which the charged oxygen moiety is alkylated. Oligonucleotides which contain a diol, such as tetraethyleneglycol or hexaethyleneglycol, at either or both termini have also been shown to be substantially resistant to nuclease degradation. An “immunostimulatory oligonucleotide”, “immunostimulatory CpG containing oligonucleotide”, or “CpG ODN” refer to an oligonucleotide, which contains a cytosine, guanine dinucleotide sequence and stimulates (e.g. has a mitogenic effect) on vertebrate lymphocyte. Preferred immunostimulatory oligonucleotides are between 2 to 100 base pairs in size and contain a consensus mitogenic CpG motif represented by the formula: 5′X1X2CGX3X43′ wherein C and G are unmethylated, X1, X2, X3 and X4 are nucleotides and a GCG trinucleotide sequence is not present at or near the 5′ and 3′ termini. Preferably the immunostimulatory oligonucleotides range between 8 to 40 base pairs in size. In addition, the immunostimulatory oligonucleotides are preferably stabilized oligonucleotides, particularly preferred are phosphorothioate stabilized oligonucleotides. In one preferred embodiment, X1X2 is the dinucleotide GpA. In another preferred embodiment, X3X4 is preferably the dinucleotide TpC or also TpT. In a particularly preferred embodiment, the consensus motif X1X2CGX3X4 is preceded on the 5′ end by a T. Particularly preferred consensus sequences are TGACGTT or TGACGTC. A “neutral oligonucleotide” refers to an oligonucleotide that does not contain an unmethylated CpG or an oligonucleotide which contains a methylated CpG dinucleotide. In a preferred embodiment, a neutralizing oligonucleotide is complementary to an immunostimulatory sequence, but contains a methylated instead of an unmethylated CpG dinucleotide sequence and therefore can compete for binding with unmethylated CpG containing oligonucleotides. In a preferred embodiment, the methylation occurs at one or more of the four carbons and two nitrogens comprising the cytosine six member ring or at one or more of the five carbons and four nitrogens comprising the guanine nine member double ring. 5′ methyl cytosine is a preferred methylated CpG. An “immunoinhibitory oligonucleotide” or “immunoinhibitory CpG containing oligonucleotide” is an oligonucleotide that. Preferable immunoinhibitory oligonucleotides are between 2 to 100 base pairs in size and can be represented by the formula: 5′GCGXnGCG3′ wherein X=a nucleotide and n=in the range of 0-50. In a preferred embodiment, X is a pyrimidine. For facilitating uptake into cells, immunoinhibitory oligonucleotides are preferably in the range of 8 to 40 base pairs in size. Prolonged immunostimulation can be obtained using stabilized oligonucleotides, particularly phosphorothioate stabilized “Palindromic sequence” shall mean an inverted repeat (i.e. a sequence such as ABCDEE′D′C′B′A′ in which A and A′ are bases capable of forming the usual Watson-Crick base pairs. In vivo, such sequences may form double stranded structures. An “oligonucleotide delivery complex” shall mean an oligonucleotide associated with (e.g. ionically or covalently bound to; or encapsulated within) a targeting means (e.g. a molecule that results in higher affinity binding to target cell (e.g. B-cell and natural killer (NK) cell) surfaces and/or increased cellular uptake by target cells). Examples of oligonucleotide delivery complexes include oligonucleotides associated with: a sterol (e.g. cholesterol), a lipid (e.g. a cationic lipid, virosome or liposome), or a target cell specific binding agent (e.g. a ligand recognized by target cell specific receptor). Preferred complexes must be sufficiently stable in vivo to prevent significant uncoupling prior to internalization by the target cell. However, the complex should be cleavable under appropriate conditions within the cell so that the oligonucleotide is released in a functional form. An “immune system deficiency” shall mean a disease or disorder in which the subject's immune system is not functioning in normal capacity or in which it would be useful to boost a subject's immune response for example to eliminate a tumor or cancer (e.g. tumors of the brain, lung (e.g. small cell and non-small cell), ovary, breast prostate, colon, as well as other carcinomas and sarcomas) or a viral (e.g. HIV, herpes), fungal (e.g. Candida sp.), bacterial or parasitic (e.g. Leishmania, Toxoplasma) infection in a subject A “disease associated with immune system activation” shall mean a disease or condition caused or exacerbated by activation of the subject's immune system. Examples include systemic lupus erythematosus, sepsis and autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. A “subject” shall mean a human or vertebrate animal including a dog, cat, horse, cow, pig, sheep, goat, chicken, monkey, rat, mouse, etc. Certain Unmethylated CpG Containing Oligos have B Cell Stimulatory Activity as Shown In Vitro and In Vivo In the course of investigating the lymphocyte stimulatory effects of two antisense oligonucleotides specific for endogenous retroviral sequences, using protocols described in the attached Examples 1 and 2, it was surprisingly found that two out of twenty-four “controls” (including various scrambled, sense, and mismatch controls for a panel of “antisense” ODN) also mediated B cell activation and IgM secretion, while the other “controls” had no effect Two observations suggested that the mechanism of this B cell activation by the “control” ODN may not involve antisense effects 1) comparison of vertebrate DNA sequences listed in GenBank showed no greater homology than that seen with non-stimulatory ODN and 2) the two controls showed no hybridization to Northern blots with 10 μg of spleen poly A+ RNA. Resynthesis of these ODN on a different synthesizer or extensive purification by polyacrylamide gel electrophoresis or high pressure liquid chromatography gave identical stimulation, eliminating the possibility of an impurity. Similar stimulation was seen using B cells from C3H/HeJ mice, eliminating the possibility that lipopolysaccharide (LPS) contamination could account for the results. The fact that two “control” ODN caused B cell activation similar to that of the two “antisense” ODN raised the possibility that all four ODN were stimulating B cells through some non-antisense mechanism involving a sequence motif that was absent in all of the other nonstimulatory control ODN. In comparing these sequences, it was/discovered that all of the four stimulatory ODN contained ODN dinucleotides that were in a different sequence context from the nonstimulatory control To determine whether the CpG motif present in the stimulatory ODN was responsible for the observed stimulation, over 300 ODN ranging in length from 5 to 42 bases that contained methylated, unmethylated, or no CpG dinucleotides in various sequence contexts were synthesized. These ODNs, including the two original “controls” (ODN 1 and 2) and two originally synthesized as “antisense” (ODN 3D and 3M; Krieg; A. M. J. Immunol. 143:2448 (1989)), were then examined for in vitro effects on spleen cells (representative sequences are listed in Table 1). Several ODN that contained CpG dinucleotides induced B cell activation and IgM secretion; the magnitude of this stimulation typically could be increased by adding more CpG dinucleotides (Table 1; compare ODN 2 to 2a or 3D to 3Da and 3 Db). Stimulation did not appear to result from an antisense mechanism or impurity. ODN caused no detectable activation of γδ or other T cell populations. Mitogenic ODN sequences uniformly became nonstimulatory if the CpG dinucleotide was mutated (Table 1; compare ODN 1 to 1a; 3D to. 3Dc; 3M to 3Ma; and 4 to 4a) or if the cytosine of the CpG dinucleotide was replaced by 5-methylcytosine (Table 1; ODN 1b, 2b, 2c, 3Dd, and 3 Mb). In contrast, methylation of other cytosines did not reduce ODN activity (ODN 1c, 2d, 3De and 3Mc). These data confirmed that a CpG motif is the essential element present in ODN that activate B cells. In the course of these studies, it became clear that the bases flanking the CpG dinucleotide played an important role in determining the B cell activation induced by an ODN. The optimal stimulatory motif was determined to consist of a CpG flanked by two 5′ purines (preferably a GpA dinucleotide) and two 3′ pyrimidines (preferably a TpT or TpC dinucleotide). Mutations of ODN to bring the CpG motif closer to this ideal improved stimulation (e.g. compare ODN 2 to 2e; 3M to 3Md) while mutations that disturbed the motif reduced stimulation (e.g. compare ODN 3D to 3Df; 4 to 4b, 4c and 4d). On the other hand, mutations outside the CpG motif did not reduce stimulation (e.g. compare ODN 1 to 1d; 3D to 3Dg; 3M to 3Me). Of those tested, ODNs shorter than 8 bases were non-stimulatory (e.g. ODN 4e). Among the forty-eight 8 base ODN tested, the most stimulatory sequence identified was TCAACGTT (ODN 4) which contains the self complementary “palindrome” AACGTT. In further optimizing this motif, it was found that ODN containing Gs at both ends showed increased stimulation, particularly if the the ODN were rendered nuclease resistant by phosphorothioate modification of the terminal internucleotide linkages. ODN 1585 (5′ GGGGTCAACGTTCAGGGGGG 3′ (SEQ ID NO:1)), in which the first two and last five internucleotide linkages are phosphorothioate modified caused an average 25.4 fold increase in mouse spleen cell proliferation compared to an average 3.2 fold increase in proliferation induced by ODN 1638, which has the same sequence as ODN 1585 except that the 10 Gs at the two ends are replaced by 10 As. The effect of the G-rich ends is cis; addition of an ODN with poly G ends but no CpG motif to cells along with 1638 gave no increased proliferation. Other octamer ODN containing a 6 base palindrome with a TpC dinucleotide at the 5′ end were also active if they were close to the optimal motif (e.g. ODN 4b,4c). Other dinucleotides at the 5′ end gave reduced stimulation (eg ODN 4f; all sixteen possible dinucleotides were tested). The presence of a 3′ dinucleotide was insufficient to compensate for the lack of a 5′ dinucleotide (eg. ODN. 4g). Disruption of the palindrome eliminated stimulation in octamer ODN (eg., ODN 4h), but palindromes were not required in longer ODN. TABLE 1 Oligonucleotide Stimulation of B Cells Stimulation Index' ODN Sequence (5′ to 3′)† 3H Uridine IgM Production 1 (SEQ ID NO: 2) GCTAGACGTTAGCGT 6.1 ± 0.8 17.9 ± 3.6 1a (SEQ. ID NO: 3) ......T........ 1.2 ± 0.2 1.7 ± 0.5 1b (SEQ ID NO: 4) ......Z........ 1.2 ± 0.1 1.8 ± 0.0 1c (SEQ ID NO: 5) ............Z.. 10.3 ± 4.4 9.5 ± 1.8 1d (SEQ ID NO: 6) ..AT......GAGC. 13.0 ± 2.3 18.3 ± 7.5 2 (SEQ ID NO: 7) ATGGAAGGTCCAGCGTTCTC 2.9 ± 0.2 13.6 ± 2.0 2a (SEQ ID NO: 8) ..C..CTC..G......... 7.7 ± 0.8 24.2 ± 3.2 2b (SEQ ID NO: 9) ..Z..CTC.ZG..Z...... 1.6 ± 0.5 2.8 ± 2.2 2c (SEQ ID NO: 10) ..Z..CTC..G......... 3.1 ± 0.6 7.3 ± 1.4 2d (SEQ ID NO: 11) ..C..CTC..G......Z.. 7.4 ± 1.4 27.7 ± 5.4 2e (SEQ ID NO: 12) ............A....... 5.6 ± 2.0 ND 3D (SEQ ID NO: 13) GAGAACGCTGGACCTTCCAT 4.9 ± 0.5 19.9 ± 3.6 3Da (SEQ ID NO: 14) .........C.......... 6.6 ± 1.5 33.9 ± 6.8 3Db (SEQ ID NO: 15) .........C.......G.. 10.1 ± 2.8 25.4 ± 0.8 3Dc (SEQ ID NO: 16) ...C.A.............. 1.0 ± 0.1 1.2 ± 0.5 3Dd (SEQ ID NO: 17) .....Z.............. 1.2 ± 0.2 1.0 ± 0.4 3De (SEQ ID NO: 18) .............Z...... 4.4 ± 1.2 18.8 ± 4.4 3Df (SEQ ID NO: 19) .......A............ 1.6 ± 0.1 7.7 ± 0.4 3Dg (SEQ ID NO: 20) .........CC.G.ACTG.. 6.1 ± 1.5 18.6 ± 1.5 3M (SEQ ID NO: 21) TCCATGTCGGTCCTGATGCT 4.1 ± 0.2 23.2 ± 4.9 3Ma (SEQ ID NO: 22) ......CT............ 0.9 ± 0.1 1.8 ± 0.5 3Mb (SEQ ID NO: 23) .......Z............ 1.3 ± 0.3 1.5 ± 0.6 3Mc (SEQ ID NO: 24) ...........Z........ 5.4 ± 1.5 8.5 ± 2.6 3Md (SEQ ID NO: 25) ......A..T.......... 17.2 ± 9.4 ND 3Me (SEQ ID NO: 26) ...............C..A. 3.6 ± 0.2 14.2 ± 5.2 4 TCAACGTT 6.1 ± 1.4 19.2 ± 5.2 4a ....GC.. 1.1 ± 0.2 1.5 ± 1.1 4b ...GCGC. 4.5 ± 0.2 9.6 ± 3.4 4c ...TCGA. 2.7 ± 1.0 ND 4d ..TT..AA 1.3 ± 0.2 ND 4e -....... 1.3 ± 0.2 1.1 ± 0.5 4f C....... 3.9 ± 1.4 ND 4g --......CT 1.4 ± 0.3 ND 4h .......C 1.2 ± 0.2 ND LPS 7.8 ± 2.5 4.8 ± 1.0 'Stimulation indexes are the means and std. dev. derived from at least 3 separate experiments, and are compared to wells cultured with no added ODN. ND = not done. CpG dinucleotides are underlined. Dots indicate identity; dashes indicate deletions. Z indicates 5 methyl cytosine.) The kinetics of lymphocyte activation were investigated using mouse spleen cells. When the cells were pulsed at the same time as ODN addition and harvested just four hours later, there was already a two-fold increase in 3H uridine incorporation. Stimulation peaked at 12-48 hours and then decreased. After 24 hours, no intact ODN were detected, perhaps accounting for the subsequent fall in stimulation when purified B cells with or without anti-IgM (at a submitogenic dose) were cultured with CpG ODN, proliferation was found to synergistically increase about 10-fold by the two mitogens in combination after 48 hours. The magnitude of stimulation was concentration dependent and consistently exceeded that of LPS under optimal conditions for both. Oligonucleotides containing a nuclease resistant phosphorothioate backbone were approximately two hundred times more potent than unmodified oligonucleotides. Cell cycle analysis was used to determine the proportion of B cells activated by CpG-ODN. CpG-ODN induced cycling in more than 95% of B cells (Table 2). Splenic B lymphocytes sorted by flow cytometry into CD23− (marginal zone) and CD23+ (follicular) subpopulations were equally responsive to ODN-induced stimulation, as were both resting and activated populations of B cells isolated by fractionation over Percoll gradients. These studies demonstrated that CpG-ODN induce essentially all B cells to enter the cell cycle. TABLE 2 Cell Cycle Analysis with CpG ODN Percent of cells in Treatment G0 G1 SA + G2 + M Media 97.6 2.4 0.02 ODN 1a 95.2 4.8 0.04 ODN 1d 2.7 74.4 22.9 ODN 3Db 3.5 76.4 20.1 LPS (30 μg/ml) 17.3 70.5 12.2 The mitogenic effects of CpG ODN on human cells, were tested on peripheral blood mononuclear cells (PBMCs) obtained from two patients with chronic lymphocytic leukemia (CLL), as described in Example 1. Control ODN containing no CpG dinucleotide sequence showed no effect on the basal proliferation of 442 cpm and 874 cpm (proliferation measured by 3H thymidine incorporation) of the human cells. However, a phosphorothioate modified CpG ODN 3Md (SEQ ID NO: 25) induced increased proliferation of 7210 and 86795 cpm respectively in the two patients at a concentration of just 1 μM. Since these cells had been frozen, they may have been less responsive to the oligos than fresh cells in vivo. In addition, cells from CLL patients typically are non-proliferating, which is why traditional chemotherapy is not effective. Certain B cell lines such as WEHI-231 are induced to undergo growth arrest and/or apoptosis in response to crosslinking of their antigen receptor by anti-IgM (Jakway, J. P. et al., “Growth regulation of the B lymphoma cell line WEHI-231 by anti-immunoglobulin, lipopolysaccharide and other bacterial products” J. Immunol. 137: 2225 (1986); Tsubata, T., J. Wu and T. Honjo: B-cell apoptosis induced by antigen receptor crosslinking is blocked by a T-cell signal through CD40.” Nature 364: 645 (1993)). WEHI-231 cells are rescued from this growth arrest by certain stimuli such as LPS and by the CD40 ligand. ODN containing the CpG motif were also found to protect WEHI-231 from anti-IgM induced growth arrest, indicating that accessory cell populations are not required for the effect. To better understand the immune effects of unmethylated CpG ODN, the levels of cytokines and prostaglandins in vitro and in vivo were measured. Unlike LPS, CpG ODN were not found to induce purified macrophages to produce prostaglandin PGE2. In fact, no apparent direct effect of CpG ODN was detected on either macrophages or T cells. In vivo or in whole spleen cells, no significant increase in the following interleukins: IL-2, IL-3, IL4, or IL-10 was detected within the first six hours. However, the level of IL-6 increased strikingly within 2 hours in the serum of mice injected with CpG ODN. Increased expression of IL-12 and interferon gamma (IFN-γ) by spleen cells was also detected within the first two hours. To determine whether CpG ODN can cause in vivo immune stimulation, DBA/2 mice were injected once intraperitoneally with PBS or phosphorothioate CpG or non-CpG ODN at a dose of 33 mg/kg (approximately 500 μg/mouse). Pharmacokinetic studies in mice indicate that this dose of phosphorothioate gives levels of approximately 10 μg/g in spleen tissue (within the effective concentration range determined from the in vitro studies described herein) for longer than twenty-four-hours (Agrawal, S. et al. (1991) Proc. Natl. Acad. Sci. USA 91:7595). Spleen cells from mice were examined twenty-four hours after ODN injection for expression of B cells surface activation markers Ly-6A/E, Bla-1, and class II MHC using three color flow cytometry and for their spontaneous proliferation using 3H thymidine: Expression of all three activation markers was significantly increased in B cells from mice injected with CpG ODN, but not from mice injected with PBS or non-CpG ODN. Spontaneous 3H thymidine incorporation was increased by 2-6 fold in spleen cells from mice injected with the stimulatory ODN compared to PBS or non-CpG ODN-injected mice. After 4 days, serum IgM levels in mice injected with CpG ODN in vivo were increased by approximately 3-fold compared to controls. Consistent with the inability of these agents to activate T cells, there was minimal change in T cell expression of the IL-2R or CD44. Degradation of phophodiester ODN in serum is predominantly mediated by 3′ exonucleases, while intracellular ODN degradation is more complex, involving 5′ and 3′ exonucleases and endonucleases. Using a panel of ODN bearing the 3D sequence with varying numbers of phosphorothioate modified linkages at the 5′ and 3′ ends, it was empirically determined that two 5′ and five 3′ modified linkages are required to provide optimal stimulation with this CpG ODN. Unmethylated CpG Containing Oligos have NK Cell Stimulatory Activity As described in further detail in Example 4, experiments were conducted to determine whether CpG containing oligonucleotides stimulated the activity of natural killer (NK) cells in addition to B cells. As shown in Table 3, a marked induction of NK activity among spleen cells cultured with CpG ODN 1 and 3Dd was observed. In contrast, there %% as relatively no induction in effectors that had been treated with non-CpG control ODN. TABLE 3 Induction Of NK Activity By CpG Oligodeoxynucleotides (ODN) % YAC-1 Specific Lysis* % 2C11 Specific Lysis Effector:Target Effector:Target ODN 50:1 100:1 50:1 100:1 None −1.1 −1.4 15.3 16.6 1 16.1 24.5 38.7 47.2 3Dd 17.1 27.0 37.0 40.0 non-CpG ODN −1.6 −1.7 14.8 15.4 Neutralizing Activity of Methylated CpG Containing Oligos B cell mitogenicity of ODN in which cytosines in CpG motifs or elsewhere were replaced by 5-methylcytosine were tested as described in Example 1. As shown in Table 1 above, ODN containing methylated CpG motifs were non-mitogenic (Table 1; ODN 1c, 2f, 3De, and 3Mc). However, methylation of cytosines other than in a CpG dinucleotide retained their stimulatory properties (Table 1, ODN 1d, 2d, 3Df, and 3Md). Immunoinhibitory Activity of Oligos Containing a GCG Trinucleotide Sequence at or Near Both Termini In some cases, ODN containing CpG dinucleotides that are not in the stimulatory motif described above were found to block the stimulatory effect of other mitogenic CpG ODN. Specifically the addition of an atypical CpG motif consisting of a GCG near or at the 5′ and/or 3′ end of CpG ODN actually inhibited stimulation of proliferation by other CpG motifs. Methylation or substitution of the cytosine in a GCG motif reverses this effect. By itself, a GCG motif in an ODN has a modest mitogenic effect, though far lower than that seen with the preferred CpG motif. Proposed Mechanisms of Action of Immunostimulatory, Neutralizing and Immunoinhibitory Oligonucleotides Unlike antigens that trigger B cells through their surface Ig receptor, CpG-ODN did not induce any detectable Ca2+ flux, changes in protein tyrosine phosphorylation, or IP 3 generation. Flow cytometry with FITC-conjugated ODN with or without a CpG motif was performed as described in Zhao, Q et al., (Antisense Research and Development 3:53-66 (1993)), and showed equivalent membrane binding, cellular uptake, efflux, and intracellular localization. This suggests that there may not be cell membrane proteins specific for CpG ODN. Rather than acting through the cell membrane, that data suggests that unmethylated CpG containing oligonucleotides require cell uptake for activity: ODN covalently linked to a solid Teflon support were nonstimulatory, as were biotinylated ODN immobilized on either avidin beads or avidin coated petri dishes. CpG ODN conjugated to either FITC or biotin retained full mitogenic properties, indicating no steric hindrance. The optimal CpG motif (TGACGTT/C is identical to the CRE (cyclic AMP response element). Like the mitogenic effects of CpG ODN, binding of CREB to the CRE is abolished if the central CpG is methylated. Electrophoretic mobility shift assays were used to determine whether CpG ODN, which are single stranded, could compete with the binding of B cell CREB/ATF proteins to their normal binding site, the doublestranded CRE. Competition assays demonstrated that single stranded ODN containing CpG motifs could completely compete the binding of CREB to its binding site, while ODN without CpG motifs could not. These data support the conclusion that CpG ODN exert their mitogenic effects through interacting with one or more-B cell CREB/ATF proteins in some way. Conversely, the presence of GCG sequences or other atypical CPG motifs near the 5′ and/or 3′ ends of ODN likely interact with CREB/ATF proteins in away that does not cause activation, and may even prevent it. The stimulatory CpG motif is common in microbial genomic DNA, but quite rare in vertebrate DNA. In addition, bacterial DNA has been reported to induce B cell proliferation and immunoglobulin (Ig) production, while mammalian DNA does not (Messina, J. P. et al., J. Immunol. 147:1759 (1991)). Experiments further described in Example 3, in which methylation of bacterial DNA with CpG methylase was found to abolish mitogenicity, demonstrates that the difference in CpG status is the cause of B cell stimulation by bacterial DNA. This data supports the following conclusion: that unmethylated CpG dinucleotides present within bacterial DNA are responsible for the stimulatory effects of bacterial DNA. Teleologically, it appears likely that lymphocyte activation by the CpG motif represents an immune defense mechanism that can thereby distinguish bacterial from host DNA. Host DNA would induce little or no lymphocyte activation due to it CpG suppression and methylation. Bacterial DNA would cause selective lymphocyte activation in infected tissues. Since the CpG pathway synergizes with B cell activation through the antigen receptor, B cells bearing antigen receptor specific for bacterial antigens would receive one activation signal through cell membrane Ig and a second signal from bacterial DNA, and would therefore tend to be preferentially activated. The interrelationship of this pathway with other pathways of B cell activation provide a physiologic mechanism employing a polyclonal antigen to induce antigen-specific responses. Method for Making Immunostimulatory Oligos For use in the instant invention, oligonucleotides can be synthesized de novo using any of a number of procedures well known in the art. For example, the β-cyanoethyl phosphoramidite method (S. L. Beaucage and M. H. Caruthers, (1981) Tet. Let. 22:1859); nucleoside H-phosphonate method (Garegg-et al., (1986) Tet. Let. 27: 4051-4054; Froehler et al., (1986) Nucl. Acid Res. 14: 5399-5407; Garegg et al., (1986) Tet. Let. 27: 4055-4058, Gaffney et al., (1988) Tet. Let. 29:2619-2622). These chemistries can be performed by a variety of automated oligonucleotide synthesizers available in the market. Alternatively, oligonucleotides can be prepared from existing nucleic acid sequences (e.g. genomic or cDNA) using known techniques, such as those employing restriction enzymes, exonucleases or endonucleases. For use in vivo, oligonucleotides are preferably relatively resistant to degradation (e.g. via endo- and exo- nucleases). Oligonucleotide stabilization can be accomplished via phosphate backbone modifications. A preferred stabilized oligonucleotide has a phosphorothioate modified backbone. The pharmacokinetics of phosphorothioate ODN show that they have a systemic half-life of forty-eight hours in rodents and suggest that they may be useful for in vivo applications (Agrawal, S. et al. (1991) Proc. Natl. Acad. Sci. USA 88:7595). Phosphorothioates may be synthesized using automated techniques employing either phosphoramidate or H phosphonate chemistries. Aryl- and alkyl- phosphonates can be made e.g. (as described in U.S. Pat. No. 4,469,863); and alkylphosphotriesters (in which the charged oxygen moiety is alkylated as described in U.S. Pat. No. 5,023,243 and European Patent No. 092,574) can be prepared by automated solid phase synthesis using commercially available reagents. Methods for making other DNA backbone modifications and substitutions have been described Uhlmann, E. and Peyman, A (1990) Chem. Rev. 90:544; Goodchild, J. (1990) Bioconjugate Chem. 1:165). For administration in vivo, oligonucleotides may be associated with a molecule that results in higher affinity binding to target cell (e.g. B-cell and natural killer (NK) cell) surfaces and/or increased cellular uptake by target cells to form an “oligonucleotide delivery complex”. Oligonucleotides can be ionically, or covalently associated with appropriate molecules using techniques which are well known in the art. A variety of coupling or crosslinking agents can be used e.g. protein A, carbodiimide, and N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP). Oligonucleotides can alternatively be encapsulated in liposomes or virosomes using well-known techniques. The present invention is further illustrated by the following Examples which in no way should be construed as further limiting. The entire contents of all of the references (including literature references, issued patents, published patent applications, and co-pending patent applications) cited throughout this application are hereby expressly incorporated by reference. Therapeutic Uses of Immunostimulatory Oligos Based on their immunostimulatory properties, oligonucleotides containing at least one unmethylated CpG dinucleotide can be administered to a subject in vivo to treat an “immune system deficiency”. Alternatively, oligonucleotides containing at least one unmethylated CpG dinucleotide can be contacted with lymphocytes (e.g. B cells or NK cells) obtained from a subject having an immune system deficiency ex vivo and activated lymphocytes can then be reimplanted in the subject Immunostimulatory oligonucleotides can also be administered to a subject in conjunction with a vaccine, as an adjuvant, to boost a subject's immune system to effect better response from the vaccine. Preferably the unmethylated CpG dinucleotide is administered slightly before or at the same time as the vaccine. Preceding chemotherapy with an immunostimulatory oligonucleotide should prove useful for increasing the responsiveness of the malignant cells to subsequent chemotherapy. CpG ODN also increased natural killer cell activity in both human and murine cells. Induction of NK activity may likewise be beneficial in cancer immunotherapy. Therapeutic Uses for Neutral Oligonucleotides Oligonucleotides that are complementary to certain target sequences can be synthesized and administered to a subject in vivo. For example, antisense oligonucleotides hybridize to complementary mRNA, thereby preventing expression of a specific target gene. The sequence-specific effects of antisense oligonucleotides have made them useful research tools for the investigation of protein function. Phase I/II human trials of systemic antisense therapy are now underway for acute myelogenous leukemia and HIV. In addition, oligonucleotide probes (i.e. oligonucleotides with a detectable label) can be administered to a subject to detect the presence of a complementary sequence based on detection of bound label. In vivo administration and detection of oligonucleotide probes may be useful for diagnosing certain diseases that are caused or exacerbated by certain DNA sequences (e.g. systemic lupus erythematosus, sepsis and autoimmune diseases). Antisense oligonucleotides or oligonucleotide probes in which any or all CpG dinucleotide is methylated, would not produce an immune reaction when administered to a subject in vivo and therefore would be safer than the corresponding non-methylated CpG containing oligonucleotide. For use in therapy, an effective amount of an appropriate oligonucleotide alone or formulated as an oligonucleotide delivery complex can be administered to a subject by any mode allowing the oligonucleotide to be taken up by the appropriate target cells (e.g. B-cells and NK cells). Preferred routes of administration include oral and transdermal (e.g. via a patch). Examples of other routes of administration include injection (subcutaneous, intravenous, parenteral, intraperitoneal, intrathecal, etc.). The injection can be in a bolus or a continuous infusion. An oligonucleotide alone or as an oligonucleotide delivery complex can be administered in conjunction with a pharmaceutically acceptable carrier. As used herein, the phrase “pharmaceutically acceptable carrier” is intended to include substances that can be coadministered with an oligonucleotide or an oligonucleotide delivery complex and allows the oligonucleotide to perform its intended function. Examples of such carriers include solutions, solvents, dispersion media, delay agents, emulsions and the like. The use of such media for pharmaceutically active substances are well known in the art. Any other conventional carrier suitable for use with the oligonucleotides falls within the scope of the instant invention. The language “effective amount” of an oligonucleotide refers to that amount necessary or sufficient to realize a desired biologic effect. For example, an effective amount of an oligonucleotide containing at least one methylated CpG for treating an immune system deficiency could be that amount necessary to eliminate a tumor, cancer, or bacterial, viral or fungal infection. An effective amount for use as a vaccine adjuvant could be that amount useful for boosting a subject's immune response to a vaccine. An “effective amount” of an oligonucleotide lacking a non-methylated CpG for use in treating a disease associated with immune system activation, could be that amount necessary to outcompete non-methylated CpG containing nucleotide sequences. The effective amount for any particular application can vary depending on such factors as the disease or condition being treated, the particular oligonucleotide being administered, the size of the subject, or the severity of the disease or condition. One of ordinary skill in the art can empirically determine the effective amount of a particular oligonucleotide without necessitating undue experimentation. The studies reported above indicate that unmethylated CpG containing oligonucleotides are directly mitogenic for lymphocytes (e.g. B cells and NK cells). Together with the presence of these sequences in bacterial DNA, these results suggest that the underrepresentation of CpG dinucleotides in animal genomes, and the extensive methylation of cytosines present in such dinucleotides, may be explained by the existence of an immune defense mechanism that can distinguish bacterial from host DNA. Host DNA would commonly be present in many anatomic regions and areas of inflammation due to apoptosis (cell death), but generally induces little or no lymphocyte activation. However, the presence of bacterial DNA containing unmethylated CpG motifs can cause lymphocyte activation precisely in infected anatomic regions, where itis beneficial. This novel activation pathway provides a rapid alternative to T cell dependent antigen specific B cell activation. However, it is likely that B cell activation would not be totally nonspecific. B cells bearing antigen receptors specific for bacterial products could receive one activation signal through cell membrane Ig, and a second from bacterial DNA, thereby more vigorously triggering antigen specific immune responses. As with other immune defense mechanisms, the response to bacterial DNA could have undesirable consequences in some settings. For example, autoimmune responses to self antigens would also tend to be preferentially triggered by bacterial infections, since autoantigens could also provide a second activation signal to autoreactive B cells triggered by bacterial DNA. Indeed the induction of autoimmunity by bacterial infections is a common clinical observance. For example, the autoimmune disease systemic lupus erythematosus, which is: i) characterized by the production of anti-DNA antibodies; ii) induced by drugs which inhibit DNA methyltransferase (Cornacchia, E. J. et al., J. Clin Invest. 92:38 (1993)); and iii) associated with reduced DNA methylation (Richardson, B., L. et al., Arth. Rheum 35:647 (1992)), is likely triggered at least in part by activation of DNA-specific B cells through stimulatory signals provided by CpG motifs, as well as by binding of bacterial DNA to antigen receptors. Further, sepsis, which is characterized by high morbidity and mortality due to massive and nonspecific activation of the immune system may be initiated by bacterial DNA and other products released from dying bacteria that reach concentrations sufficient to directly activate many lymphocytes. Lupus, sepsis and other “diseases associated with immune system activation” may be treated, prevented or ameliorated by administering to a subject oligonucleotides lacking an unmethylated CpG dinucleotide (e.g. oligonucleotides that do not include a CpG motif or oligonucleotides in which the CpG motif is methylated) to block the binding of unmethylated CpG containing nucleic acid sequences. Oligonucleotides lacking an unmethylated CpG motif can be administered alone or in conjunction with compositions that block an immune cell's reponse to other mitogenic bacterial products (e.g. LPS). The following serves to illustrate mechanistically how oligonucleotides containing an unmethylated CpG dinucleotide can treat, prevent or ameliorate the disease lupus. Lupus is commonly thought to be triggered by bacterial or viral infections. Such infections have been reported to stimulate the production of nonpathogenic antibodies to single stranded DNA. These antibodies likely recognize primarily bacterial sequences including unmethylated CpGs. As disease develops in lupus, the anti-DNA antibodies shift to pathogenic antibodies that are specific for double-stranded DNA. These antibodies would have increased binding for methylated CpG sequences and their production would result from a breakdown of tolerance in lupus. Alternatively, lupus may result when a patient's DNA becomes hypomethylated, thus allowing anti-DNA antibodies specific for unmethylated CpGs to bind to self DNA and trigger more widespread autoimmunity through the process referred to as “epitope spreading”. In either case, it may be possible to restore tolerance in lupus patients by coupling antigenic oligonucleotides to a protein carrier such as gamma globulin (IgG). Calf-thymus DNA complexed to gamma globulin has been reported to reduce anti-DNA antibody formation. Therapeutic Uses of Oligos Containing GCG Trinucleotide Sequences at or Near Both Termini Based on their interaction with CREB/ATF, oligonucleotides containing GCG trinucleotide sequences at or near both termini have antiviral activity, independent of any antisense effect due to complementarity between the oligonucleotide and the viral sequence being targeted. Based on this activity, an effective amount of inhibitory oligonucleotides can be administered to a subject to treat or prevent a viral infection. EXAMPLES Example 1 Effects of ODNs on B Cell Total RNA Synthesis and Cell Cycle B cells were purified from spleens obtained from 6-12 wk old specific pathogen free DBA/2 or BXSB mice (bred in the University of Iowa animal care facility; no substantial strain differences were noted) that were depleted of T cells with anti-Thy-1.2 and complement and centrifugation over lympholyte M (Cedarlane Laboratories, Hornby, Ontario, Canada) (“B cells”). B cells contained fewer than 1% CD4+ or CD8+ cells. 8×104 B cells were dispensed in triplicate into 96 well microtiter plates in 100 μl RPMI containing 10% FBS (heat inactivated to 65° C. for 30 min.), 50 μM 2-mercaptoethanol, 100 U/ml penicillin, 100 ug/ml streptomycin, and 2 mM L-glutamate. 20 μM ODN were added at the start of culture for 20 h at 37° C., cells pulsed with 1 μCi of 3H uridine, and harvested and counted 4 hr later. Ig secreting B cells were enumerated using the ELISA spot assay after culture of whole spleen cells with ODN at 20 μM for 48 hr. Data, reported in Table 1, represent the stimulation index compared to cells cultured without ODN. Cells cultured without ODN gave 687 cpm, while cells cultured with 20 μg/ml LPS (determined by titration to be the optimal concentration) gave 99,699 cpm in this experiment. 3H thymidine incorporation assays showed similar results, but with some nonspecific inhibition by thymidine released from degraded ODN (Matson. S and A. M. Krieg (1992) Nonspecific suppression of 3H-thymidine incorporation by control oligonucleotides. Antisense Research and Development 2:325). For cell cycle analysis, 2×106 B cells were cultured for 48 hr. in 2 ml tissue culture medium alone, or with 30 μg/ml LPS or with the indicated phosphorothioate modified ODN at 1 μM. Cell cycle analysis was performed as described in (Darzynkiewicz, Z. et al., Proc. Natl. Acad. Sci. USA 78:2881 (1981)). To test the mitogenic effects of CpG ODN on human cells, perpheral blood monocyte cells (PBMCs) were obtained from two patients with chronic lymphocytic leukemia (CLL), a disease in which the circulating cells are malignant B cells. Cells were cultured for 48 hrs and pulsed for 4 hours with tritiated thymidine as described above. Example 2 Effects of ODN on Production of IgM from B cells Single cell suspensions from the spleens of freshly killed mice were treated with anti-Thyl, anti-CD4, and anti-CD8 and complement by the method of Leibson et al., J. Exp. Med. 154:1681 (1981)). Resting B cells (<02% T cell contamination) were isolated from the 63-70% band of a discontinuous Percoll gradient by the procedure of DeFranco et al, J. Exp. Med. 155:1523 (1982). These were cultured as described above in 30 μM ODN or 20 μg/ml LPS for 48 hr. The number of B cells actively secreting IgM was maximal at this time point, as determined by ELIspot assay (Klinman D. M. et al. J. Immunol. 144:506 (1990)). In that assay, B cells were incubated for 6 hrs on anti-Ig coated microtiter plates. The Ig they produced (>99% IgM) was detected using phosphatase-labelled anti-Ig (Southern Biotechnology Associated, Birmingham, Ala.). The antibodies produced by individual B cells were visualized by addition of BCIP (Sigma Chemical Co., St. Louis Mo.) which forms an insoluble blue precipitate in the presence of phosphatase. The dilution of cells producing 20-40 spots/well was used to determine the total number of antibody-secreting B cells/sample. All assays were performed in triplicate. In some experiments, culture supernatants were assayed for IgM by ELISA, and showed similar increases in response to CpG-ODN. table 1 Example 3 B Cell Stimulation by Bacterial DNA DBA/2 B cells were cultured with no DNA or 50 μg/ml of a) Micrococcus lysodeikticus; b) NZB/N mouse spleen; and c) NFS/N mouse spleen genomic DNAs for 48 hours, then pulsed with 3H thymidine for 4 hours prior to cell harvest. Duplicate DNA samples were digested with DNAse I for 30 minutes at 37 C prior to addition to cell cultures. E coli DNA also induced an 8.8 fold increase in the number of IgM secreting B cells by 48 hours using the ELISA-spot assay. DBA/2 B cells were cultured with either no additive, 50 μg/ml LPS or the ODN 1; 1a; 4; or 4a at 20 μM. Cells were cultured and harvested at 4, 8, 24 and 48 hours. BXSB cells were cultured as in Example 1 with 5, 10, 20, 40 or 80 μM of ODN 1; 1a; 4; or 4a or LPS. In this experiment, wells with no ODN had 3833 cpm. Each experiment was performed at least three times with similar results. Standard deviations of the triplicate wells were <5%. Example 4 Effects of ODN on Natural Killer (NK) Activity 10×106 C57BL/6 spleen cells were cultured in two ml RPMI (supplemented as described for Example 1) with or without 40 μM CpG or non-CpG ODN for forty-eight hours. Cells were washed, and then used as effector cells in a short term 51Cr release assay with YAC-1 and 2C11, two NK sensitive target cell lines (Ballas, Z. K. et al. (1993) J. Immunol. 150:17). Effector cells were added at various concentrations to 104 51Cr-labeled target cells in V-bottom microtiter plates in 0.2 ml, and incubated in 5% CO2 for 4 hr. at 37° C. Plates were then centrifuged, and an aliquot of the supernatant counted for radioactivity. Percent specific lysis was determined by calculating the ratio of the 51Cr released in the presence of effector cells minus the 51Cr released when the target cells are cultured alone, over the total counts released after cell lysis in 2% acetic acid minus the 51Cr cpm released when the cells are cultured alone. Example 5 In Vivo Studies with CpG Phosphorothioate ODN Mice were weighed and injected IP with 0.25 ml of sterile PBS or the indicated phophorothioate ODN dissolved in PBS. Twenty four hours later, spleen cells were harvested, washed, and stained for flow cytometry using phycoerythrin conjugated 6B2 to gate on B cells in conjunction with biotin conjugated anti Ly-6A/E or anti-Iad (Pharmingen, San Diego, Calif.) or anti-Bla-1 (Hardy, R. R et al., J. Exp. Med. 159:1169 (1984). Two mice were studied for each condition and analyzed individually. Example 6 Titration of Phosphorothioate ODN for B Cell Stimulation B cells were cultured with phosphorothioate ODN with the sequence of control ODN 1a or the CpG ODN 1d and 3 Db and then either pulsed after 20 hr with 3H uridine or after 44 hr with 3H thymidine before harvesting and determining cpm. Example 7 Rescue of B Cells From Apoptosis WEHI-231 cells (5×104/well) were cultured for 1 hr. at 37 C in the presence or absence of LPS or the control ODN 1a or the CpG ODN. 1d and 3 Db before addition of anti-IgM (1 μ/ml). Cells were cultured for a further 20 hr. before a 4 hr. pulse with 2 μCi/well 3H thymidine. In this experiment, cells with no ODN or anti-IgM gave 90.4×103 by addition of anti-IgM. The phosphodiester ODN shown in Table 1 gave similar protection, though with some nonspecific suppression due to ODN degradation. Each experiment was repeated at least 3 times with similar results. Example 8 In Vivo Induction of IL-6 DBA/2 female mice (2 mos. old) were injected 1P with 500 μg CpG or control phosphorothioate ODN. At various time points after injection, the mice were bled. Two mice were studied for each time point. IL-6 was measured by Elisa, and IL-6 concentration was calculated by comparison to a standard curve generated using recombinant IL-6. The sensitivity of the assay was 10 pg/ml. Levels were undetectable after 8 hr. Example 9 Binding of B cell CREB/ATF to a Radiolabelled Doublestranded CRE Probe (CREB). Whole cell extracts from CH12.LX B cells showed 2 retarded bands when analyzed by EMSA with the CRE probe (free probe is off the bottom of the figure). The CREB/ATF protein(s) binding to the CRE were competed by the indicated amount of cold CRE, and by single-stranded CpG ODN, but not by non-CpG ODN. Equivalents Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents of the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>DNA Binds to Cell Membrane and is Internalized In the 1970's, several investigators reported the binding of high molecular weight DNA to cell membranes (Lerner, R. A., W. Meinke, and D. A. Goldstein. 1971. “Membrane-associated DNA in the cytoplasm of diploid human lymphocytes”. Proc. Natl. Acad. Sci. USA 68:1212; Agrawal, S. K, R. W. Wagner, P. K. McAllister, and B. Rosenberg. 1975. “Cell-surface-associated nucleic acid in tumorigenic cells made visible with platinum-pyrimidine complexes by electron microscopy”. Proc. Nat. Acad. Sci. USA 72:928). In 1985 Bennett et al. presented the first evidence that DNA binding to lymphocytes is similar to a ligand receptor interaction: binding is saturable, competitive, and leads to DNA endocytosis and degradation (Bennett, R. M., G. T. Gabor, and M. M. Merritt, 1985. “DNA binding to human leukocytes. Evidence for a receptor-mediated association, internalization, and degradation of DNA”. J Clin. Invest. 76:2182). Like DNA, oligodeoxyribonucleotides (ODNs) are able to enter cells in a saturable, sequence independent, and temperature and energy dependent fashion (reviewed in Jaroszewski, J. W., and J. S. Cohen. 1991. “Cellular uptake of antisense oligodeoxynucleotides”. Advanced Drug Delivery Reviews 6:235; Akhtar, S., Y. Shoji, and R. L. Juliano. 1992. “Pharmaceutical aspects of the biological stability and membrane transport characteristics of antisense oligonucleotides”. In: Gene Regulation: Biology of Antisense RNA and DNA . R. P. Erickson, and J. G. Izant, eds. Raven Press, Ltd. New York, pp. 133; and Zhao, Q., T. Waldschimdt, E. Fisher, C. J. Herrera, and A. M. Krieg., 1994. “Stage specific oligonucleotide uptake in murine bone marrow B cell precursors”. Blood, 84:3660). No receptor for DNA or ODN uptake has yet been cloned, and it is not yet clear whether ODN binding and cell uptake occurs through the same or a different mechanism from that of high molecular weight DNA. Lymphocyte ODN uptake has been shown to be regulated by cell activation. Spleen cells stimulated with the B cell mitogen LPS had dramatically enhanced ODN uptake in the B cell population, while spleen cells treated with the T cell mitogen Con A showed enhanced ODN uptake by T but not B cells (Krieg, A. M., F. Grnelig-Meyling, M. F. Gourley, W. J. Kisch, L. A. Chrisey, and A. D. Steinberg. 1991. “Uptake of oligodeoxyribonucleotides by lymphoid cells is heterogeneous and inducible”. Antisense Research and Development 1:161). Immune Effects of Nucleic Acids Several polynucleotides have been extensively evaluated as biological response modifiers. Perhaps the best example is poly (I,C) which is a potent inducer of IFN production as well as a macrophage activator and inducer of NK activity (Talmadge, J. E., J. Adams, H. Phillips, M. Collins, B. Lenz, M. Schneider, E. Schlick, R. Ruffmann, R. H. Wiltrout, and M. A. Chirigos. 1985. “Immunomodulatory effects in mice of polyinosinic-polycytidylic acid complexed with poly-L:-lysine and carboxymethylcellulose”. Cancer Res. 45:1058; Wiltrout, R. H., R. R. Salup, T. A. Twilley, and J. E. Talmadge. 1985. “Immunomodulation of natural killer activity by polyribonucleotides”. J. Biol. Resp. Mod 4:512; Krown, S. E. 1986. “Interferons and interferon inducers in cancer treatment”. Sem. Oncol. 13:207; and Ewel, C. H., S. J. Urba, W. C. Kopp, J. W. Smith II, PG. Steis, J. L. Rossio, D. L. Longo, M. J. Jones, W. G. Alvord, C. M. Pinsky, J. M. Beveridge, K. L. McNitt, and S. P. Creekmore. 1992. “Polyinosinic-polycytidylic acid complexed with poly-L-lysine and carboxymethylcellulose in combination with interleukin 2 in patients with cancer: clinical and immunological effects”. Canc. Res. 52:3005). It appears that this murine NK activation may be due solely to induction of IFN β secretion (Ishikawa, R., and C. A. Biron. 1993. “IFN induction and associated changes in splenic leukocyte distribution”. J. Immunol. 150:3713). This activation was specific for the ribose sugar since deoxyribose was ineffective. Its potent in vitro antitumor activity led to several clinical trials using poly (I,C) complexed with poly-L-lysine and carboxymethylcellulose (to reduce degradation by RNAse) (Talmadge, J. E., et al., 1985. cited supra; Wiltrout, R. H., et al., 1985. cited supra); Krown, S. E., 1986. cited supra); and Ewel, C. H., et al. 1992. cited supra). Unfortunately, toxic side effects have thus far prevented poly (I,C) from becoming a useful therapeutic agent. Guanine ribonucleotides substituted at the C8 position with either a bromine or a thiol group are B cell mitogens and may replace “B cell differentiation factors” (Feldbush, T. L., and Z. K. Ballas. 1985. “Lymphokine-like activity of 8-mercaptoguanosine: induction of T and B cell differentiation”. J. Immunol. 134:3204; and Goodman, M. G. 1986. “Mechanism of synergy between T cell signals and C8-substituted guanine nucleosides in humoral immunity: B lymphotropic cytokines induce responsiveness to 8-mercaptoguanosine”. J. Immunol. 136:3335). 8-mercaptoguanosine and 8-bromoguanosine also can substitute for the cytokine requirement for the generation of MHC restricted CT1 (Feldbush, T. L., 1985. cited supra), augment murine NK activity (Koo, G. C., M. E. Jewell, C. L. Manyak, N. H. Sigal, and L. S. Wicker. 1988. “Activation of murine natural killer cells and macrophages by 8-bromoguanosine”. J. Immunol. 140:3249), and synergize with IL-2 in inducing murine LAK generation (Thompson, R. A., and Z. K. Ballas. 1990. “Lymphokine-activated killer (LAK) cells. V. 8-Mercaptoguanosine as an IL-2-sparing agent in LAK generation”. J. Immunol. 145:3524). The NK and LAK augmenting activities of these C8-substituted guanosines appear to be due to their induction of IFN (Thompson, R. A., et al. 1990. cited supra). Recently, a 5′ triphosphorylated thymidine produced by a mycobacterium was found to be mitogenic for a subset of human γδ T cells (Constant, P., F. Davodeau, M. -A. Peyrat, Y. Poquet, G. Puzo, M. Bonneville, and J. -J. Fournie. 1994. “Stimulation of human γε T cells by nonpeptidic mycobacterial ligands” Science 264:267). This report indicated the possibility that the immune system may have evolved ways to preferentially respond to microbial nucleic acids. Several observations suggest that certain DNA structures may also have the potential to activate lymphocytes. For example, Bell et al. reported that nucleosomal protein-DNA complexes (but not naked DNA) in spleen cell supernatants caused B cell proliferation and immunoglobulin secretion (Bell, D. A., B. Morrison, and P. VandenBygaart. 1990. “Immunogenic DNA-related factors”. J. Clin. Invest. 85:1487). In other cases, naked DNA has been reported to have immune effects. For example, Messina et al. have recently reported that 260 to 800 bp fragments of poly (dG)•(dC) and poly (dG•dC) were mitogenic for B cells (Messina, J. P., G. S. Gilkeson, and D. S. Pisetsky. 1993. “The influence of DNA structure on the in vitro stimulation of murine lymphocytes by natural and synthetic polynucleotide antigens”. Cell. Immunol. 147:148). Tokunaga, et al. have reported that dGe dC induces γ-IFN and NK activity (Tokunaga, S. Yamamoto, and K Namba. 1988. “A synthetic single-stranded DNA, poly(dG,dC), induces interferon-α/β and -γ, augments natural killer activity, and suppresses tumor growth” Jpn. J Cancer Res. 79:682). Aside from such artificial homopolymer sequences, Pisetsky et al. reported that pure mammalian DNA has no detectable immune effects, but that DNA from certain bacteria induces B cell activation and immunoglobulin secretion (Messina, J. P., G. S. Gilkeson, and D. S. Pisetsky. 1991. “Stimulation of in vitro murine lymphocyte proliferation by bacterial DNA”. J. Immunol. 147:1759). Assuming that these data did not result from some unusual contaminant, these studies suggested that a particular structure or other characteristic of bacterial DNA renders it capable of triggering B cell activation. Investigations of mycobacterial DNA sequences have demonstrated that ODN which contain certain palindrome sequences can activate NK cells (Yanamoto, S., T. Yamamoto, T. Kataoka, E. Kuramoto, O. Yano, and T. Tokunaga. 1992. “Unique palindromic sequences in synthetic oligonucleotides are required to induce INF and augment INF-mediated natural killer activity”. J. Immunol. 148:4072; Kuramoto, E., O. Yano, Y. Kimura, M. Baba, T. Makino, S. Yamamoto, T. Yamamoto, T. Kataoka, and T. Tokunaga 1992. “Oligonucleotide sequences required for natural killer cell activation”. Jpn. J Cancer Res. 83:1128). Several phosphorothioate modified ODN have been reported to induce in vitro or in vivo B cell stimulation (Tanaka, T., C. C. Chu, and W. E. Paul. 1992. “An antisense oligonucleotide complementary to a sequence in Iγ2b increases γ2b germline transcripts, stimulates B cell DNA synthesis, and inhibits immunoglobulin secretion”. J. Exp. Med 175:597; Branda, R. F., A. L. Moore, L. Mathews, J. J. McCormack, and G. Zon. 1993. “Immune stimulation by an antisense oligomer complementary to the rev gene of HIV-1”. Biochem. Pharmacol. 45:2037; McIntyre, K. W., K Lombard-Gillooly, J. R Perez, C. Kunsch, U. M. Sarmiento, J. D. Larigan, K. T. Landreth, and R Narayanarn 1993. “A sense phosphorothioate oligonucleotide directed to the initiation codon of transcription factor NF-κ β T65 causes sequence-specific immune stimulation”. Antisense Res. Develop. 3:309; and Pisetsky, D. S., and C. F. Reich 1993. “Stimulation of murine lymphocyte proliferation by a phosphorothioate oligonucleotide with antisense activity for herpes simplex virus”. Life Sciences 54:101). These reports do not suggest a common structural motif or sequence element in these ODN that might explain their effects. The CREB/ATF Family of Transcription Factors and their Role in Replication The cAMP response element binding protein (CREB) and activating transcription factor (ATF) or CREB/ATF family of transcription factors is a ubiquitously expressed class of transcription factors of which 11 members have so far been cloned (reviewed in de Groot, R. P., and P. Sassone-Corsi: “Hormonal control of gene expression: Multiplicity and versatility of cyclic adenosine 3′,5′-monophosphate-responsive nuclear regulators”. Mol. Endocrin. 7:145, 1993; Lee, K. A. W., and N. Masson: “Transcriptional regulation by CREB and its relatives”. Biochim Biophys. Acta 1174:221, 1993.). They all belong to the basic region/leucine zipper (bZip) class of proteins. All cells appear to express one or more CREB/ATF proteins, but the members expressed and the regulation of mRNA splicing appear to be tissue-specific. Differential splicing of activation domains can determine whether a particular CREB/ATF protein will be a transcriptional inhibitor or activator. Many CREB/ATF proteins activate viral transcription, but some splicing variants which lack the activation domain are inhibitory. CREB/ATF proteins can bind DNA as homo- or hetero- dimers through the cAMP response element, the CRE, the consensus form of which is the unmethylated sequence TGACGTC (binding is abolished if the CpG is methylated) (Iguchi-Ariga, S. M. M., and W. Schaffner: “CpG methylation of the cAMP-responsive enhancer/promoter sequence TGACGTCA abolishes specific factor binding as well as transcriptional activation”. Genes & Develop. 3:612, 1989.). The transcriptional activity of the CRE is increased during B cell activation (Xie, H. T. C. Chiles, and T. L. Rothstein: “Induction of CREB activity via the surface Ig receptor of B cells”. J. Immunol. 151:880, 1993.). CREB/ATF proteins appear to regulate the expression of multiple genes through the CRE including immunologically important genes such as fos, jun B, Rb-1, IL-6, IL-1 (Tsukada, J., K. Saito, W. R. Waterman, A. C. Webb, and P. E. Auron: “Transcription factors NF-IL6 and CREB recognize a common essential site in the human prointerleukin 1β gene”. Mol. Cell. Biol. 14:7285, 1994; Gray, G. D., O. M. Hernandez, D. Hebel, M. Root, J. M. Pow-Sang, and E. Wickstrom: “Antisense DNA inhibition of tumor growth induced by c-Ha-ras oncogene in nude mice”. Cancer Res. 53:577, 1993), IFN-β (Du, W., and T. Maniatis: “An ATF/CREB binding site protein is required for virus induction of the human interferon B gene”. Proc. Natl. Acad. Sci. USA 89:2150, 1992), TGF-β1(Asiedu, C. K., L. Scott, R. K. Assoian, M. Ehrlich: “Binding of AP-1/CREB proteins and of MDBP to contiguous sites downstream of the human TGF-B 1 gene”. Biochim. Biophys. Acta 1219:55, 1994.), TGF-β2, class II MHC (Cox, P. M., and C. R. Goding: “An ATF/CREB binding motif is required for aberrant constitutive expression of the MHC class II DRa promoter and activation by SV40 T-antigen”. Nucl. Acids Res. 20:4881, 1992.), E-selectin, GM-CSF, CD-8α, the germline Igα constant region gene, the TCR Vβ gene, and the proliferating cell nuclear antigen (Huang, D., P. M. Shipman-Appasamy, D. J. Orten, S. H. Hinrichs, and M. B. Prystowsky: “Promoter activity of the proliferating-cell nuclear antigen gene is associated with inducible CRE-binding proteins in interleukin 2-stimulated T lymphocytes”. Mol. Cell. Biol. 14:4233, 1994.). In addition to activation through the cAMP pathway, CREB can also mediate transcriptional responses to changes in intracellular Ca ++ concentration (Sheng, M., G. McFadden, and M. E. Greenberg: “Membrane depolarization and calcium induce c-fos transcription via phosphorylation of transcription factor CREB”. Neuron 4:571, 1990). The role of protein-protein interactions in transcriptional activation by CREB/ATF proteins appears to be extremely important. Activation of CREB through the cyclic AMP pathway requires protein kinase A (PKA), which phosphorylates CREB 341 on ser 133 and allows it to bind to a recently cloned protein, CBP (Kwok, R. P. S., J. R. Lundblad, J. C. Chrivia, J. P. Richards, H. P. Bachinger, R. G. Brennan, S. G. E. Roberts, M. R Green, and R. H. Goodman: “Nuclear protein CBP is a coactivator for the transcription factor CREB”. Nature 370:223, 1994; Arias, J., A. S. Alberts, P. Brindle, F. X. Claret, T. Smea, M. Karin, J. Feramisco, and M. Montminy: “Activation of cAMP and mitogen responsive genes relies on a common nuclear factor”. Nature 370:226, 1994.). CBP in turn interacts with the basal transcription factor TFIIB causing increased transcription. CREB also has been reported to interact with dTAFII 110, a TATA binding protein-associated factor whose binding may regulate transcription (Ferreri, K., G. Gill, and M. Montminy: “The cAMP-regulated transcription factor CREB interacts with a component of the TFIID complex”. Proc. Natl. Acad. Sci. USA 91:1210, 1994.). In addition to these interactions, CREB/ATF proteins can specifically bind multiple other nuclear factors (Hoeffler, J. P., J. W. Lustbader, and C. -Y. Chen: “Identification of multiple nuclear factors that interact with cyclic adenosine 3′,5′-monophosphate response element-binding protein and activating transcription factor-2 by protein-protein interactions”. Mol. Endocrinol. 5:256, 1991) but the biologic significance of most of these interactions is unknown. CREB is normally thought to bind DNA either as a homodimer or as a heterodimer with several other proteins. Surprisingly, CREB monomers constitutively activate transcription (Krajewski, W., and K. A. W. Lee: “A monomeric derivative of the cellular transcription factor CREB functions as a constitutive activator”. Mol. Cell Biol. 14:7204, 1994.). Aside from their critical role in regulating cellular transcription, it has recently been shown that CREB/ATF proteins are subverted by some infectious viruses and retroviruses, which require them for viral replication. For example, the cytomegalovirus immediate early promoter, one of the strongest known mammalian promoters, contains eleven copies of the CRE which are essential for promoter function (Chang, Y. -N., S. Crawford, J. Stall, D. R Rawlins, K. -T. Jeang, and G. S. Hayward: “The palindromic series I repeats in the simian cytomegalovirus major immediate-early promoter behave as both strong basal enhancers and cyclic AMP response elements”. J. Virol. 64:264, 1990). At least some of the transcriptional activating effects of the adenovirus E1A protein, which induces many promoters, are due to its binding to the DNA binding domain of the CREB/ATF protein, ATF-2, which mediates E1A inducible transcription activation (Liu, F., and M. P Green: “Promoter targeting by adenovirus E1a through interaction with different cellular DNA-binding domains”. Nature 368:520, 1994). It has also been suggested that E1A binds to the CREB-binding protein, CBP (Arany, Z., W. R. Sellers, D. M. Livingston, and R. Eckner: “E1A-associated p300 and CREB-associated CBP belong to a conserved family of coactivators”. Cell 77:799, 1994). Human T lymphotropic virus-I (HTLV-1), the retrovirus which causes human T cell leukemia and tropical spastic paresis, also requires CREB/ATF proteins for replication. In this case, the retrovirus produces a protein, Tax, which binds to CREB/ATF proteins and redirects them from their normal cellular binding sites to different DNA sequences (flanked by G- and C-rich sequences) present within the HTLV transcriptional enhancer (Paca-Uccaralertkun, S., L. -J. Zhao, N. Adya, J. V. Cross, B. R Cullen, I. M. Boros, and C.-Z. Giam: “In vitro selection of DNA elements highly responsive to the human T-cell lymphotropic virus type I transcriptional activator, Tax”. Mol. Cell. Biol. 14:456, 1994; Adya, N., L. -J. Zhao, W. Huang, I. Boros, and C. -Z. Giam: “Expansion of CREB's DNA recognition specificity by Tax results from interaction with Ala-Ala-Arg at positions 282-284 near the conserved DNA-binding domain of CREB”. Proc. Natl. Acad. Sci. USA 91:5642, 1994). | <SOH> SUMMARY OF THE INVENTION <EOH>The instant invention is based on the finding that certain oligonucleotides containing unmethylated cytosine-guanine (CpG) dinucleotides activate lymphocytes as evidenced by in vitro and in vivo data. Based on this finding, the invention features, in one aspect, novel immunostimulatory oligonucleotide compositions. In a preferred embodiment, an immunostimulatory oligonucleotide is synthetic, between 2 to 100 base pairs in size and contains a consensus mitogenic CpG motif represented by the formula: in-line-formulae description="In-line Formulae" end="lead"? 5′X 1 X 2 CGX 3 X 4 3′ in-line-formulae description="In-line Formulae" end="tail"? wherein C and G are unmethylated, X 1 , X 2 , X 3 and X 4 are nucleotides and a GCG trinucleotide sequence is not present at or near the 5′ and 3′ termini. For facilitating uptake into cells, CpG containing immunostimulatory oligonucleotides are preferably in the range of 8 to 40 base pairs in size. Prolonged immunostimulation can be obtained using stabilized oligonucleotides, particularly phosphorothioate stabilized oligonucleotides. Enhanced immunostimulatory activity has been observed where X 1 X 2 is the dinucleotide GpA and/or X 3 X 4 is the dinucleotide is most preferably TpC or also TpT. Further enhanced immunostimulatory activity has been observed where the consensus motif X 1 X 2 CGX 3 X 4 is preceded on the 5′ end by a T. In a second aspect, the invention features useful methods, which are based on the immunostimulatory activity of the oligonucleotides. For example, lymphocytes can either be obtained from a subject and stimulated ex vivo upon contact with an appropriate oligonucleotide; or a non-methylated CpG containing oligonucleotide can be administered to a subject to facilitate in vivo activation of a subject's lymphocytes. Activated lymphocytes, stimulated by the methods described herein (e.g. either ex vivo or in vivo), can boost a subject's immune response. The immunostimulatory oligonucleotides can therefore be used to treat, prevent or ameliorate an immune system deficiency (e.g., a tumor or cancer or a viral, fungal, bacterial or parasitic infection in a subject. In addition, immunostimulatory oligonucleotides can also be administered as a vaccine adjuvant, to stimulate a subject's response to a vaccine. Further, the ability of immunostimulatory cells to induce leukemic cells to enter the cell cycle, suggests a utility for treating leukemia by increasing the sensitivity of chronic leukemia cells and then administering conventional ablative chemotherapy. In a third aspect, the invention features neutral oligonucleotides (i.e. oligonucleotide that do not contain an unmethylated CpG or which contain a methylated CpG dinucleotide). In a preferred embodiment, a neutralizing oligonucleotide is complementary to an immunostimulatory sequence, but contains a methylated instead of an unmethylated CpG dinucleotide sequence and therefore can compete for binding with unmethylated CpG containing oligonucleotides. In a preferred embodiment, the methylation occurs at one or more of the four carbons and two nitrogens comprising the cytosine six member ring or at one or more of the five carbons and four nitrogens comprising the guanine nine member double ring. 5′ methyl cytosine is a preferred methylated CpG. In a fourth aspect, the invention features useful methods using the neutral oligonucleotides. For example, in vivo administration of neutral oligonucleotides should prove useful for treating diseases such as systemic lupus erythematosus, sepsis and autoimmune diseases, which are caused or exacerbated by the presence of unmethylated CpG dimers in a subject In addition, methylation CpG containing antisense oligonucleotides or oligonucleotide probes would not initiate an immune reaction when administered to a subject in vivo and therefore would be safer than corresponding unmethylated oligonucleotides. In a fifth aspect, the invention features immunoinhibitory oligonucleotides, which are capable of interfering with the activity of viral or cellular transcription factors. In a preferred embodiment, immunoinhibitory oligonucleotides are between 2to 100 base pairs in size and contain a consensus immunoinhibitory CpG motif represented by the formula: in-line-formulae description="In-line Formulae" end="lead"? 5 ′GCGXnGCG 3 ′ in-line-formulae description="In-line Formulae" end="tail"? wherein X=a nucleotide and n=in the range of 0-50. In a preferred embodiment, X is a pyrimidine. For facilitating uptake into cells, immunoinhibitory oligonucleotides are preferably in the range of 8 to 40 base pairs in size. Prolonged immunostimulation can be obtained using stabilized oligonucleotides, particularly phosphorothioate stabilized oligonucleotides. In a sixth and final aspect, the invention features various uses for immunoinhibitory oligonucleotides. Immunoinhibitory oligonucleotides have antiviral activity, independent of any antisense effect due to complementarity between the oligonucleotide and the viral sequence being targeted. Other features and advantages of the invention will become more apparent from the following detailed description and claims. detailed-description description="Detailed Description" end="lead"? | 20040709 | 20120403 | 20050217 | 64077.0 | 0 | ARCHIE, NINA | IMMUNOMODULATORY OLIGONUCLEOTIDES | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,888,135 | ACCEPTED | Energy efficient TMP refining of destructured chips | A system and method for thermomechanical refining of wood chips comprises preparing the chips for refining by exposing the chips to an environment of steam to soften the chips, compressively destructuring and dewatering the softened chips to a solids consistency above 55 percent, and diluting the destructured and dewatered chips to a consistency in the range of about 30 to 55 percent. The destructuring partially defibrates the material. This diluted material is fed to a rotating disc primary refiner wherein each of the opposed discs has an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves. The destructured and partially defibrated chips are substantially completely defibrated in the inner ring and the resulting fibers are fibrillated in the outer ring. The compressive destructuring, dewatering, and dilution can all be implemented in one integrated piece of equipment immediately upstream of the primary refiner, and the fiberizing and fibrillating are both achieved between only one set of relatively rotating discs in the primary refiner. | 1. A system for producing thermomechanical pulp in a rotating disc refiner from wood chips that have been steamed, comprising: a pressurized macerating screw device having an inlet end for receiving the steamed chips, a working section for subjecting the chips to maceration and dewatering under high mechanical compression forces in an environment of saturated steam to destructure the chips, and a discharge end where the dewatered and destructured chips expand; means at the discharge end of the screw device, for introducing dilution water into the dewatered and destructured chips, whereby the dilution water penetrates the expanding chips and together with the chips forms a refiner feed material having a solids consistency in the range of about 30 to 55 percent; a primary refiner having relatively rotating discs each having a working plate thereon, the working plates being arranged in confronting coaxial relation thereby defining a refiner gap which extends substantially radially outward from the inner diameter of the discs to the outer diameter of the discs; each plate having a radially inner fiberizing ring and a radially outer fibrillating ring, each ring having an inner feeding region and an outer working region, wherein the working region of the inner ring is defined by a first pattern of alternating bars and grooves, and the feeding region of the outer ring is defined by a second pattern of alternating bars and grooves, said first pattern on the working region on the inner ring having relatively narrower grooves than the grooves of said second pattern on the feeding region on the outer ring; and a refiner feed device for receiving the feed material and delivering the feed material between the discs at substantially the inner diameter of the discs. 2. The system of claim 1, wherein the working section of the pressurized macerating screw includes a dewatering portion, having a perforated tubular wall and a flighted coaxial shaft of uniform diameter rotatable therein, and a plug portion immediately following the dewatering portion, having a solid tubular wall and an unflighted shaft of greater diameter than in the dewatering portion, thereby defining a constricted flow cross section for macerating the chips under high compression; and the discharge end of the pressurized macerating screw includes an expansion wall that outwardly flares from the solid tubular wall of the plug portion and a conical valve coaxial with the shaft and confronting the expansion wall in axially adjustable spaced relation, thereby defining an adjustable expansion volume. 3. The system of claim 2, wherein the means for introducing dilution water includes at least one fluid nozzle penetrating the flared expansion wall for introducing dilution water into said adjustable expansion volume. 4. The system of claim 2, wherein the means for introducing dilution water includes at least one fluid nozzle penetrating the conical valve for introducing dilution water into said adjustable expansion volume. 5. The system of claim 1, wherein the working region of outer ring has a third pattern of alternating bars and grooves, and the grooves in the third pattern of the outer ring are narrower than the grooves in the first pattern of the working region of the inner ring. 6. The system of claim 1, including an annular space between the inner ring and the outer ring. 7. The system of claim 6, wherein some but not all of the bars in the feed region of the outer ring extend into said annular space. 8. The system of claim 1, wherein the inner ring and the outer ring are distinct members attached to a common refiner disc. 9. The system of claim 1, wherein the inner ring and the outer ring are integrally formed on a common base. 10. The system of claim 1, wherein each plate has a total radius extending to the outer circumference of the outer ring and each ring has a respective radial width, and the radial width of the inner ring is less then the radial width of the outer ring. 11. The system of claim 10, wherein the radial width of the inner ring is less than about 35% of said total radius. 12. The system of claim 10, wherein the radial width of the feed region of the inner ring is larger than the radial width of the working region of the inner ring, and the radial width of the feed region in the outer ring is less than the radial width of the working region of the outer ring. 13. The system of claim 10, wherein the pattern of bars and grooves in the working region of the outer ring has at least two zones, one of said zones contiguous with the feed region of the outer ring and another of said zones contiguous with the outer circumference of said outer ring; and the pattern of bars and grooves in said one zone is less dense than the pattern of bars and grooves in said other zone. 14. The system of claim 13, wherein the pattern of bars and grooves throughout the working region of the inner ring has a uniform density. 15. The system of claim 1, wherein the pattern of bars and grooves throughout the working region of the inner ring has a first uniform density and the pattern of bars and grooves throughout the feed region of the outer ring has a second uniform density. 16. The system of claim 1, wherein the relatively rotating discs comprise a rotor disc and an opposed stator; the outer ring of the rotor has curved feeding bars in the feeding region; and the feeding region in the outer ring on the stator has a substantially flat portion to accommodate the curved feeding bars. 17. A system for producing thermomechanical pulp in a refiner having relatively rotating discs from wood chips that have been steamed comprising: a compression screw discharger having an inlet end for receiving the steamed chips, a working section for subjecting the chips to maceration and dewatering under high mechanical compression forces, and a discharge end where the macerated, dewatered and compressed chips are discharged as conditioned chips into an expansion volume where the conditioned chips expand; means for introducing dilution water into the expansion volume, whereby the dilution water penetrates the expanding chips and together with the chips forms a high consistency refiner feed material; a primary refiner having relatively rotating discs each having refining plate means thereon, the plate means being arranged in confronting coaxial relation thereby defining a gap which extends substantially radially outwardly from the inner diameter of the discs to the outer diameter of the discs; each plate means having a radially inner ring and a radially outer ring, each ring having a refiner working region of alternating bars and grooves, the working region on the inner ring having relatively larger bars and grooves and the working region on the outer ring having relatively smaller bars and grooves; and a refiner feed device for receiving the feed material from the expansion volume and delivering the material to the gap between the discs at substantially the inner diameter of the discs. 18. The system of claim 17, wherein each ring has an inner feeding region have a coarser pattern of bars and grooves than the respective working region; and the feeding region of the outer ring has a coarser pattern than the working region of the inner ring. 19. A method for thermomechanical refining of wood chips comprising: exposing the chips to an environment of steam to soften the chips; macerating and partially defibrating the softened chips in a compression device; feeding the destructured and partially defibrated chips to a rotating disc primary refiner, wherein opposed discs each have an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves; and substantially completing fiberization of the chips in the inner ring and fibrillating the resulting fibers in the outer ring. 20. The method of claim 19, wherein each ring has an inner feeding region and an outer working region; the working region of the inner ring is defined by a first pattern of alternating bars and grooves, and the feeding region of the outer ring is defined by a second pattern of alternating bars and grooves; said first pattern on the working region on the inner ring has relatively narrower grooves than the grooves of said second pattern on the feeding region on the outer ring; said fiberization of the chips is substantially completed in the working region of the inner ring with low intensity refining; and said fibrillation of the fibers is performed in the working region of the outer ring with high intensity refining. 21. A method for thermomechanical refining of wood chips comprising: exposing the chips to an environment of steam to soften the chips; compressively destructuring and dewatering the softened chips to a solids consistency above 55 percent; diluting the destructured and dewatered chips to a consistency in the range of about 30 to 55 percent; feeding the diluted destructured chips to a rotating disc primary refiner, wherein opposed discs each have an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves; and fiberizing the chips in the inner ring and fibrillating the resulting fibers in the outer ring. 22. The method of claim 21, wherein the chips are softened in an environment of steam at atmospheric pressure. 23. The method of claim 21, wherein the softened chips are conveyed to a steam tube having a pressure in the range of about 0-30 psig for a holding period in the range of about 30-180 seconds before the chips are compressively destructured. 24. The method of claim 21, wherein the softened chips are conveyed to a steam tube having a pressure in the range of about 0-30 psig for a holding period in the range of about 10-40 seconds before the chips are compressively destructured. 25. The method of claim 21, wherein the softened chips are conveyed to a steam tube having a pressure in the range of about 5-30 psig for a holding period in the range of about 10-40 seconds before the chips are compressively destructured. 26. The method of claim 21, wherein the compressive destructuring and dewatering are performed in a macerating plug screw discharger having a steam inlet pressure in the range of about 0-30 psig. 27. The method of claim 21, wherein the compressive destructuring and dewatering are performed in a macerating plug screw discharger having a steam inlet pressure in the range of about 5-30 psig, for a period of less than 15 seconds. 28. The method of claim 21, wherein the relatively rotating discs of the refiner are in a casing having an environment of steam at an operating pressure greater than 30 psig and said dilution and feeding are performed in an environment of steam at substantially the same pressure as the refiner operating pressure. 29. The method of claim 21, wherein the relatively rotating discs of the refiner are in a casing having an environment of steam at an operating pressure greater than 75 psig, said dilution and feeding are performed in an environment of steam at substantially the same pressure as the refiner operating pressure, and the chips are diluted, fed to the refiner and introduced between the discs within a time period of less than about 10 seconds. 30. A composite plate for attachment to a disc of a rotating disc refiner, comprising: an inner ring having an inner feed region defined by a first coarse pattern of bars and grooves and an outer working region defined by a first fine pattern of bars and grooves; an outer ring having an inner feed region defined by a second coarse pattern of bars and grooves and an outer working region defined by a second fine pattern of bars and grooves; wherein the second coarse pattern of bars and grooves has a greater density of grooves than the first coarse pattern of bars and grooves and the second fine pattern of bars and grooves has a greater density of grooves than the first fine pattern of bars and grooves. 31. The composite plate of claim 30, including an annular space between the inner ring and the outer ring. 32. The composite plate of claim 31, wherein some but not all of the bars in the feed region of the outer ring extend into said annular space. 33. The composite plate of claim 30, wherein the inner ring and the outer ring are distinct members. 34. The composite plate of claim 33, wherein the inner ring and the outer ring are attached to a common disc. 35. The composite plate of claim 30, wherein the inner ring and the outer ring are integrally formed on a common base. 36. The composite plate of claim 30, wherein the composite plate has a total radius extending to the outer circumference of the outer ring and each ring has a respective radial width, and the radial width of the inner ring is less then the radial width of the outer ring. 37. The composite plate of claim 36, wherein the radial width of the inner ring is less than about 35% of said total radius. 38. The composite plate of claim 36, wherein the radial width of the feed region of the inner ring is larger than the radial width of the working region of the inner ring, and the radial width of the feed region in the outer ring is less than the radial width of the working region of the outer ring. 39. The composite plate of claim 38, wherein the pattern of bars and grooves in the working region of the outer ring has at least two zones, one of said zones contiguous with the feed region of the outer ring and another of said zones contiguous with the outer circumference of said outer ring, and the pattern of bars and grooves in said one zone is less dense than the pattern of bars and grooves in said other zone. 40. The composite plate of claim 39, wherein the pattern of bars and grooves throughout the working region of the inner ring has a uniform density. 41. The composite plate of claim 36, wherein the pattern of bars and grooves in the working region of the outer ring has at least two zones, one of said zones contiguous with the feed region of the outer ring and another of said zones contiguous with the outer circumference of said outer ring, and the pattern of bars and grooves in said one zone is less dense than the pattern of bars and grooves in said other zone. 42. The composite plate of claim 30, wherein the course pattern of bars and grooves in the inner feed region of the outer ring includes a plurality of curved bars. 43. The composite plate of claim 42, wherein the bars in the feeding and working regions of the outer ring have respective heights and the curved bars in the feed region have a height greater than the height of the bars in the working region. | BACKGROUND OF THE INVENTION The present invention relates to apparatus and method for thermomechanical pulping of lignocellulosic material, particularly wood chips. In recent decades, the quality of mechanical pulp produced by thermomechanical pulping (TMP) techniques has been improving, but the rising cost of energy for these energy-intensive techniques imposes even greater incentives for energy efficiency while maintaining quality. The present inventor has already advanced the state of the art as embodied in the Andritz RTS™, RT Pressafiner™, and RT Fibration™, process technologies. He discovered an operating window by which feed material is preheated for a very short residence time at high temperature and pressure, then refined at such high temperature and pressure between opposed discs rotating at high speed. (U.S. Pat. No. 5,776,305). A further improvement was directed to pretreating the feed chips before preheating, by conditioning in a pressurized steam environment and compressing the conditioned chips in the pressurized steam environment. (PCT/US98/14718). Yet another improvement is disclosed in International Application PCT/US2003/022057, where the feed chips discharged from the pretreatment step, are fiberized without fibrillation, for example with a low intensity refiner, before delivery to a high intensity refiner. The underlying principle in the progression of the foregoing developments has been to distinguish and handle in distinct equipment, the axial fiber separation and fiberization of the chip material, from the fibrillation of the fibers to produce pulp. The former steps are performed in dedicated equipment upstream of the refiner, using low energy consumption that matches the relatively low degree of working and fiber separation, while the high energy consuming refiner is relieved of the energy-inefficient defibering function and can devote all the energy more efficiently to the fibrillation function. This is necessary since the fibrillation function requires even more energy than defibering (also known as defibration) These developments did indeed improve energy efficiency, especially in systems that employ high-speed discs (i.e., above 1500 rpm for double disc and above 1800 rpm for single disc refiners). However, especially for systems that did not employ high-speed refiners, the long-term energy efficiency was offset to some extent in the short term by the need for more costly or more space-occupying equipment upstream of the primary refiner. SUMMARY OF THE INVENTION The object of the invention is to provide a simplified system and method for producing high quality thermomechanical pulps at lower energy consumption. The simplification includes facilitating the supply of lower cost systems capable of accelerated commissioning and start-up. In essence, the invention achieves significant energy efficiency, even in systems that do not employ a high speed refiner, while reducing the scope and complexity of the equipment needed upstream of the refiner. This object is achieved by synthesizing the concepts underlying the RTS, RT Pressafiner, and RT Fibration process technologies, and using a simplified equipment train. The equipment for implementing the invention requires only a pressurized screw discharger (PSD) and refiner(s). Significant modifications, however, are required to the PSD and the associated refining process. The PSD is of the destructuring variety (macerating pressurized screw discharger, or MPSD) with increasing root diameter and plug zone complete with blowback valve (BBV). MPSD inlet pressure may span from atmospheric to about 30 psig, preferably 5-25 psig. This component of the process simulates RT Pressafiner pretreatment. Higher dilution flow is necessary to maintain nominal refining consistencies, since the MPSD dewaters to higher solids content than conventional PSD screws. Fiberizing inner plates (inner rings) in the primary refiner are designed to effectively feed and fiberize destructured wood chips. This component of the process is used to simulate RT Fibration. High-efficiency outer plates (outer rings) in the primary refiner are designed for feeding (high intensity =>minimum energy consumption) or restraining (low intensity =>maximum strength development), or intensity levels between the two extremes, depending on product quality and energy requirements. In a broad aspect, the invention is directed to a method for thermomechanical refining of wood chips comprising exposing the chips to an environment of steam to soften the chips, macerating and partially defibrating the softened chips in a compression device, feeding the destructured and partially defibrated chips to a rotating disc primary refiner, wherein opposed discs each have an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves, a substantially completing fiberization (defibration) of the chips in the inner ring and fibrillating the resulting fibers in the outer ring. The system implementation preferably includes an inner feeding region and an outer working region on the inner ring and an inner feeding region and an outer working region on the outer ring, wherein the working region of the inner ring is defined by a first pattern of alternating bars and grooves, and the feeding region of the outer ring is defined by a second pattern of alternating bars and grooves. The first pattern on the working region on the inner ring has relatively narrower grooves than the grooves of the second pattern on the feeding region on the outer ring. The fiberization of the chips is substantially completed in the working region of the inner ring with low intensity refining, while the fibrillation of the fibers is performed in the working region of the outer ring at a smaller plate gap and higher refining intensity. The inventive method preferably comprises the steps of exposing the chips to an environment of steam to soften the chips, compressively destructuring and dewatering the softened chips to a consistency greater than about 55%, diluting the destructured and dewatered chips to a consistency in the range of about 30% to 55%, feeding the diluted destructured chips to a rotating disc refiner, where opposed discs each have an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves, fiberizing (defibrating) the chips in the inner ring, and fibrillating the resulting fibers in the outer ring. The compressive destructuring, dewatering, and dilution can all be implemented in one integrated piece of equipment immediately upstream of the primary refiner, and the fiberizing and fibrillating are both achieved between only one set of relatively rotating discs in the primary refiner. The new, simplified TMP refining method, combining a destructuring PSD and fiberizing inner plates, was shown to effectively improve TMP pulp property versus energy relationships relative to conventional TMP pulping. The method improved the pulp property/energy relationships for three commercially available processes: TMP, RT, and RTS. The RT and RTS refining configurations refer to low retention and higher pressure refining, typically between 75 psig and 95 psig, at standard refiner disc speeds (RT) or higher disc speeds (RTS). The defibration efficiency of the inner refining zone improved at higher refining pressure. The level of defibration further increased with an increase in refiner disc speed. Thermomechanical pulps produced with holdback outer rings had higher overall strength properties compared to pulps with expelling outer rings. The latter configuration required less energy to a given freeness and had lower shive content. The specific energy savings to a given freeness using the inventive method in combination with expelling outer plates was 15%, 22%, and 32% for the TMP, RT, and RTS series, respectively, compared to the control TMP pulps. Combining the inventive method with bisulfite treatment improved pulp strength properties and significantly increased pulp brightness. Higher dilution flow effectively compensated for the higher discharge solids exiting the MSD-type PSD. The dilution/impregnation apparatus should ensure thorough penetration of the chips exiting the MPSD. One option is a split dilution strategy that adds dilution to both the MPSD discharge and in-refiner. In the present context, maceration should be understood as the physical mechanism associated with solid material under compressive shearing forces. Maceration of wood chips in a steam-pressurized screw device or the like, destructures the material without breakage across grain boundaries, resulting in significant but not complete (e.g., up to about 30%) axial separation of the fibers. The majority of the maceration occurs in the plug zone after the flights, but some initial maceration can occur in the flighted section before the plug zone. The restriction in the plug zone can increase compression and maceration to some degree in the earlier flighted section. Impregnation liquid (water and/or chemicals) is added directly in the expansion region or chamber at the discharge of the macerating screw device such that the liquid uptake into the expanding wood structure is immediate. The destructured wood chips should be sufficiently saturated with liquid such that the refining consistency is in a preferable range for optimum pulp. All or most of the liquid uptake takes place at the discharge of the MPSD as the heavily compressed chips are released. In the alternative embodiment, the dilution liquid is split, with some dilution at the MPSD screw discharge and further dilution introduced between the inner and outer refiner rings. The latter configuration is useful when excessive saturation is observed at the MPSD discharge but additional dilution is beneficial (after the inner rings) to further optimize the fibrillation refining. As an example but not a limitation, the consistency in the plug-pipe zone is typically in the range of 58%-65%, and in the expansion zone with impregnation/dilution, in the range of about 30%-55%. The material remains at this consistency range through the seal off zone of the BBV (which is not normally a full seal and is thus similar in pressure to the expansion zone), at the exit from the seal off zone, and at the inlet to the refiner ribbon feeder. This is a pressurized environment so vaporization is taking place, but the goal is to target the optimum refining consistency, usually around 35%-55%, as delivered to the refiner feed device for introduction between the refiner plates. In most cases the bar/grooves in the working zone of the outer rings (fibrillation) must be finer than in the working zone of the inner rings (defibration). To produce a mechanical pulp fiber, the fiber must first be defibrated (separated from the wood structure) and then fibrillated (stripping of fiber wall material). A key feature of this invention is that the working zone of the inner rings primarily defibrates and the working zone of the outer rings primarily fibrillates. A significant aspect of the novelty of the invention is maximizing the separation of these two mechanisms in a single machine and by that more effectively optimizing the fiber length and pulp property versus energy relationships. Since defibration in the inner rings takes place on relatively large destructured chips, the associated working region pattern of bars and grooves cannot be too fine. Otherwise the destructured chips would not adequately pass through the grooves of the inner rings and be distributed evenly. The defibrated material as received in the outer ring feed region from the inner ring and distributed to the outer ring working region, is relatively smaller and thus the pattern of bars and grooves in the working region of the outer ring is finer than in the inner ring. Another benefit of the invention is that more even distribution (i.e., higher fiber coverage across refiner plates) occurs both in the inner rings and outer rings compared to conventional processes. Better feeding means better feed stability, which decreases refiner load swings, which in turn helps maintain more uniform pulp quality. An important benefit of the present invention is that the retention time is minimized at each functional step of the process. This is possible because the fibrous material is sufficiently size reduced at each step in the process such that the operating pressures can almost instantaneously heat and soften the fiber to the required level. The process can be considered as having three functional steps: (1) producing destructured chips, (2) defibrating the destructured chips, and (3) fibrillating the defibrated material. The equipment configuration should establish minimum retention time from the MPSD discharge of step (1) to the refiner inlet. The refiner feed device (e.g., ribbon feeder or side entry feeder) operates almost instantaneously for initiating step (2) in the inner rings. The inner ring design should establish a retention time for the material to pass through uninhibited. Some inner ring designs may have longer residence than others to effectively defibrate, but the net retention time is still less than if fibration were performed in a separate component. The defibrated material passes almost instantaneously to the outer ring where step (3) is achieved. Here also, the retention time is low. The actual retention time in the outer ring will be dictated by the design of plates chosen to optimize pulp properties and energy consumption. The benefit of this very low retention (minimum) at each process step (while achieving necessary fiber softening for maintaining pulp strength properties) is maximum optical properties. In the system described in my prior International Application PCT/052003/022057, wherein the destructured chips were defibrated in a smaller fiberizer refiner before delivery to the main, primary refiner for fibrillation, the pressures were much lower in the fiberizing (defibration) step. The fiberizing retention time at pressure was much longer in a completely separate refiner. It was desirable to maintain a lower temperature to help preserve pulp brightness, since the low intensity refining intensity was gentle. High temperatures were therefore neither necessary nor desirable in the separate fiberizing refiner to preserve pulp strength. In the present invention, defibration and fibrillation are performed within the same highly pressurized refiner casing. The refining intensity in the fiberizing (defibrating) inner ring is still low, achieved at high pressure and a low retention time. There is no negative impact on brightness despite the high pressure (temperature), because the retention time is so short. This is analogous to the surprisingly beneficial effect of low preheat retention time at high temperature as described in my U.S. Pat. No. 5,776,305 (RTS mechanism). When the present invention is implemented in an RTS system, there is no need for a separate preheat conveyor immediately upstream of the refiner feed device, because the destructured chips heat up rapidly during normal conveyance from the MPSD to the refiner. The environment from the expansion volume or chamber to the rotating discs is the refiner operating pressure, e.g., 75 to 95 psig for RTS, and the “retention time” at the corresponding saturation temperature during conveyance between the MPSD and refiner is well under 10 seconds, preferably in the range of 2-5 seconds, corresponding to the preferred RTS preheat retention time. More generally, the process advantage of achieving energy efficient production of quality TMP pulp with minimum time at each process step, has the corollary advantage of minimizing the component, space, and cost requirements of equipment for implementing the process. Almost any installed TMP, RT-TMP, or RTS-TMP system can be upgraded according to at least some aspects of the present invention, without increasing the equipment footprint in the mill. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic of a TMP refiner system that illustrates an embodiment of the invention; FIGS. 2A and B are schematics of alternatives of a macerating pressurized screw with dilution injection feature, suitable for use with the present invention; FIG. 3 is a schematic representation of a portion of a refiner disc plate, showing the inner fiberizer ring and the distinct outer fibrillation ring; FIGS. 4 A and B show an exemplary inner, fiberizing ring pair for the rotor and stator, respectively, having angled bars and grooves; FIG. 5 shows the relationship of the inner, fiberizing ring pair to the outer, fibrillation ring pair, at the transition region; FIGS. 6 A and B show another exemplary fiberizing ring pair, having substantially radial bars and grooves; FIGS. 7 A and B show an exemplary outer, fibrillating ring, in front and side views, respectively, and FIGS. 7 C, D, and E show section views across the bars and grooves in the outer, middle, and inner zones, respectively; FIGS. 8 A, B and C show another exemplary outer, fibrillating ring in front and section views, respectively; FIG. 8D shows a side and front view, respectively, of an exemplary outer ring for a rotor disc, having curved feeding bars; FIG. 8E shows a side and front view, respectively, of an exemplary opposing outer ring for a stator, to be employed with the outer ring of FIG. 8D; FIG. 9 is a schematic of the plate used in laboratory experiments to model and obtain measurements of the operational characteristics inner fiberizing plate; FIG. 10 is a schematic of the plate used in laboratory experiments to model and obtain measurements of the operational characteristics outer, fibrillating plate; FIGS. 11-18 illustrate pulp property results for most of the refiner series produced in this investigation; DESCRIPTION OF THE PREFERRED EMBODIMENTS 1 Overview FIG. 1 shows a TMP refiner system 10 according to the preferred embodiment of the invention. A standard atmospheric inlet plug screw feeder 12 receives presteamed (softened) chips from source S at atmospheric pressure P1=0 psig and delivers pre-steamed wood chips at pressure P2=0 psig to a steam tube 14 where the chips are exposed to an environment of saturated steam at a pressure P3. Depending on the system configuration, the pressure P3 can range from atmospheric to about 15 psig or from 15 to up to about 25 psig with holding times in the range of a few seconds to many minutes. The chips are delivered to a macerating pressurized plug screw discharger (MPSD) 16. The macerating pressurized plug screw discharger 16 has an inlet end 18 at a pressure P4 in the range of about 5 to 25 psig, for receiving the steamed chips. Preferably, the MPSD has an inlet pressure P4 that is the same as the pressure P3 in the steam tube 14. The MPSD has a working section 20 for subjecting the chips to dewatering and maceration under high mechanical compression forces in an environment of saturated steam, and a discharge end 22 where the macerated, dewatered and compressed chips are discharged as conditioned chips into an expansion zone or chamber at pressure P5 where the conditioned chips expand. Nozzles or similar means are provided for introducing impregnation liquid and dilution water into the discharge end of the screw device, whereby the dilution water penetrates the expanding chips and together with the chips forms a refiner feed material in feed tube 24 having a solids consistency in the range of about 30 to 55 percent. Alternatively, especially if no impregnation apart from dilution is required, the dilution can be achieved in a dilution chamber that is connected to but not necessarily integral with the MSD discharge. In this context, maceration or destructuring of the chips means that axial fiber separation exceeds about 20 percent, but there is no fibrillation. A high consistency primary refiner 26 has relatively rotating discs in casing 28 that is maintained at pressure P5, each disc, having a working plate thereon, the working plates being arranged in confronting coaxial relation thereby defining a space which extends substantially radially outward from the inner diameter of the discs to the outer diameter of the discs. Each plate has a radially inner ring and a radially outer ring, each ring having a pattern of alternating bars and grooves. The pattern on the inner ring has relatively larger bars and grooves and the pattern on the outer ring has relatively smaller bars and grooves. A refiner feed device 30, such as a ribbon feeder, receives the feed material from the dilution region associated with the MPSD (directly or via an intermediate buffer bin) and delivers the material at pressure P5 to the space between the discs at substantially the inner diameter of the discs. As will be described in greater detail below, the inner ring completes the fiberizing (defibration) of the chip material and the outer ring fibrillates the fibers. The refiner can be a single disc refiner (one rotating plate faces a stationary stator plate), a double disc refiner (opposed counter-rotating discs), or a Twin disc refiner available from Andritz Inc., Muncy Pa., where a central stator has plates on both sides, and each side faces a rotating disc. The feed devices for a double disc or Twin disc refiner would be somewhat different than that for a single disc refiner, as is known in the relevant field of endeavor. The system may be backfit into any of the three core processes of (1) typical TMP, (2) RT-TMP, or (3) RTS-TMP. In the typical TMP, the first PSF 12 or rotary valve maintains separation between upstream atmospheric conditions and the elevated pressure in the steam tube that acts as a preheater in the pressure range of about 0-30 psig for a typical hold time of 30 seconds to 180 seconds. As per the invention, the second PSF at the discharge of the steaming tube (typically called a plug screw discharger or PSD) is converted or replaced with an RTPressafiner (macerating pressurized plug screw discharger=MPSD) screw device. In the RT-TMP and RTS-TMP configurations, the first PSF or rotary valve serves essentially the same purpose and the steaming tube can be operated in a range from 0-30 psig. In all configurations the first PSF is not necessary should a mill elect to operate the inlet to the MPSD (RTPressafiner) at atmospheric conditions (0 psig). It is noted that the benefit of pressurizing the inlet during RTPressafiner pretreatment is lost when operating at atmospheric conditions, which can result in fiber damage when processing softwoods using a PSD screw of the destructuring variety. Atmospheric conditions may be satisfactory when processing, for example hardwoods, which have much shorter fiber length to begin with. The typical TMP process is referred to as PRMP when no pressurized presteaming is conducted at the inlet to the MPSD. The material discharging from the MPSD (RTPressafiner) then discharges into the higher temperatures of the refining environment. At RT- or RTS- conditions the refining environment is at a higher temperature, which corresponds to the high pressure (above 75 psig, corresponding to a temperature well above the lignin transition temperature, Tg) in the refiner. In this embodiment, the total time the material is above Tg before delivery to the discs, should be less than 15 seconds, preferably less than 5 seconds. This can be summarized in the following table: System Conditions For Invention in Three Backfit Embodiments Component Conditions TMP RT-TMP RTS-TMP Pressure P1 @ chip 0 psig 0 psig 0 psig source S Pressure P2 @ PSF 12 0-30 psig 0-30 psig 0-30 psig outlet Pressure P3 @ steam 0-30 psig 0-30 psig 0-30 psig tube 14 Holding time steam 30-180 sec 10-40 sec 10-40 sec tube 14 Inlet pressure P4 @ 0-30 psig 0-30 psig 0-30 psig MPSD 16 Processing time in <15 sec <15 sec <15 sec MPSD 16 Pressure P5 @ 30-60 psig 75-95 psig 75-95 psig expansion volume 22, refiner feeder 30 and casing 28 Dwell time in <10 sec <10 sec <10 sec expansion volume 22 refiner feeder 30 and casing 28 FIGS. 2A and B are schematics of a macerating pressurized screw 16 with dilution injection feature, suitable for use with the present invention. According to the embodiment of FIG. 2A, chip material 32 is shown in the central, dewatering portion of working section 20, where the diameters of the perforated tubular wall 34, rotatable coaxial shaft 36, and flights 38 are constant. A chip plug 40 is formed in the plug portion of the working section, immediately following the dewatering portion, where the wall is imperforate and the shaft has no flights but the shaft diameter increases substantially, producing a narrowed flow cross section and thus a high back pressure that enhances the extrusion of liquid from the chips, through the drain holes formed in the wall of the central portion. The constricted flow and macerating effect may be further enhanced or adjusted by use of a tubular constriction insert (not shown) within the imperforate wall, or rigid pins or the like (not shown) projecting from the wall into the plugged material. The plug is highly compressed under mechanical pressures typically in the range of 1000 psi to 3000 psi, or higher. Most if not all of the maceration occurs in the plug. The chips are substantially fully destructured, with partial defibration exceeding about 20 percent usually approaching 30 percent or more. At the end of the plug, the discharge end 22 of the MPSD has an increased cross sectional area, defined between an outwardly flared wall 42 and the confronting, spaced conical surface 44 of the blow back valve. 46. The blow back valve is axially adjustable from a stop position nested in a conical recess 48 at the end of the MPSD shaft 36, to a maximum retracted position. This adjusts the flow area of the expansion zone or volume 50 while maintaining a mild degree of sealing at 52 by chip material between the valve against the outer end of the flared wall, which can be controlled in response to transient pressure differential between the feed tube 24 and the MPSD 16. In the expansion zone 50, impregnating liquor is fed under high pressure either through a plurality of pressure hoses 54 and associated nozzles (as shown), or a pressurized circular ring. The dewatered chips entering the expansion zone 50 quickly absorb the impregnation fluid and expand, helping to form the weak sealing zone at the end of the expansion zone. FIG. 2B shows an alternative whereby the impregnation in the expansion zone 50 is achieved by providing fluid flow openings 56 in the face of the conical blow back valve, which can be supplied via high pressure hoses through the shaft 58 of the blow back valve. The feed tube 24 is preferably a vertical drop tube for directing and mixing the diluted chips from the MPSD 16 to the feed device 30 of the refiner. However, it should be understood that the pressure P5 in the feed tube 24 is the same pressure as in the feed device 30 and refiner casing 28. A small pressure boost or drop may be desired between the refiner feed device 30 and refiner casing 28, which is common practice in the field of TMP. Regardless, the pressures throughout this region following the MPSD to the refiner casing would typically be well above 30 psig, usually above 45 psig, which is much higher than the MPSD inlet steam pressure P4. However, the plug 40 is so highly mechanically compressed that even with the tube pressure as high as 95 psig or more, the compressed plug will quickly expand in the expansion zone due to the expansion of pores in the fibers in the uncompressed state. It can thus be appreciated that the feed tube can act as an expansion chamber in contributing to the effectiveness of the expansion volume. Practitioners in this field could readily modify the design and relationship of the expansion zone and feed tube so that expansion and dilution occur predominantly in a dedicated expansion chamber that is attached to but not integral with the MPSD. FIG. 3 is a schematic representation of a portion of refiner disc plate 100, showing the inner fiberizer ring 102 and the outer fibrillation ring 104. Each ring can be a distinct plate member attachable to the disc, or the rings can be integrally formed on a common base that is attachable to a disc. Each ring has an inner feeding region 106, 108 and an outer working region 110, 112. The working (defibrating) region of the inner ring is defined by a first pattern of alternating bars 114 and grooves 116, and the feeding region of the outer ring is defined by a second pattern of alternating bars 118 and grooves 120. The very course bars 122 and grooves 124 in the feeder region 106 of the inner ring direct the previously destructured chip material into the defibrating region 110 of significantly narrower bars and grooves. The fiberized material then intermixes in and crosses the transition annulus 126, where it is enters the feed region 108 of the outer ring. In general, the first pattern on the working region 110 on the inner ring has relatively narrower grooves than the grooves of the second pattern on the feeding region 108 on the outer ring. The working (fibrillating) region 112 of the outer ring has a pattern of bars 128 and grooves 130 wherein the grooves 130 are narrower than the grooves 116 of the working region 110 of the inner ring. The coarse bars and grooves of the feeding region 106 of the inner ring on one disc can be juxtaposed with a feeding region on the opposed disc that has no bars and grooves, so long as the shape of the feed flow path readily directs the feed material from the ribbon feeding device into the working regions 110 of the opposed inner rings. Thus, every inner ring 102 will have an outer, fiberizing region 110 with a pattern of alternating bars and grooves 114, 116 but the associated inner region 106 will not necessarily have a pattern of bars and grooves. The outer region 112 of the fibrillating ring 104 can have a plurality of radially sequenced zones, such as 132, 134, and/or a plurality of differing but laterally alternating fields, in a manner that is well known for the “refining zone” in TMP refiners, such as 136, 138. In FIG. 3, the outer ring 104 has an inner, feeding region 108 of alternating bars and grooves, and the working region 112 has a first pattern of alternating bars and grooves 128, 130 appearing as laterally repeating trapezoids in zone 132, and another pattern of alternating bars and grooves 140, 142 appearing as laterally repeating trapezoids in zone 134 that extend to the circumference 144 of the plate. The annular space 126 between the inner and outer rings 102, 104 can be totally clear, or as shown in FIG. 3, some of the bars such as 146 in the outer ring feed region 108 can extend into the annular space. The annular space 126 delineates the radial dimension of the inner and outer rings, whereby the radial width of the inner ring 102 is less than the radial width of the outer ring 104, preferably less than about 35 percent of the total radius of the plate from the inner edge 148 of the inner ring 102 to the circumferential edge 144 of the outer ring 104. Also, the radial width of the feed region 106 of the inner ring 102 is larger than the radial width of the working region 110 of the inner ring, whereas the radial width of the feed region 108 in the outer ring 104 is less than the radial width of the working region 112. The type of plate described above with reference to FIG. 3 will for convenience be referred to as an “RTF” plate. The destructured and partially defibrated chip material enters the inner feed region 106 where no substantial further defibration occurs, but the material is fed into the working region 110 where energy-efficient low intensity action of the bars and grooves 114, 116 defibrates substantially all of the material. Such plates can be beneficially used as replacement plates in refiner systems that may not have an associated pressurized macerating discharger. Where a PMSD is present, the combination of full destructuring and partial defibration along with high heat upstream of the refiner allows the plate designer to minimize the radial width and energy usage in the working region 110 of the inner ring for completing defibration. The pattern of bars and grooves 114, 116 and the width of the working region 110 can be varied as to intensity and retention time. Even with less than ideal upstream destructuring and partial defibration, the plate designer can increase the radial width of the inner working zone 110 and chose a pattern that retains the material somewhat for enhanced working, while still achieving satisfactory fibrillation in a shortened high intensity outer ring 112 and overall energy savings for a given quality of primary pulp. Moreover, the invention does not preclude that with the RTF plates, some defibration may occur in the outer ring 104 or some fibrillation may occur in the inner ring 102. The composite plate shown in FIG. 3 is merely representative. FIGS. 4, and 6 show other possible regions for the inner rings. FIG. 4A shows one inner ring 150A and FIG. 4B shows the opposed inner ring 150B. FIG. 5 shows a schematic juxtaposition of opposed inner rings 150A and 150B, with portions of the associated outer rings 152A and 152B as installed in the refiner. The feed gap 154 of the inner rings is preferably curved to redirect the feed material received at the “eye” of the discs from the axially conveyed direction, toward the radial working gap 156 of the inner rings. Preferably, the feeder bars (very coarse bars) are spaced apart by more than the size of the material in the feed. For example, the smallest of the three dimensions defining the chips (chip thickness) is typically 3-5 mm. This is to avoid severe impact, which results in fiber damage in the wood matrix. In most instances, the minimum gap 154 during operation should be 5 mm. The coarse feeder bars have the sole function of supplying the outer part of the inner ring with adequate feed distribution and should do no work on the chips. The feeder bars are provided on the rotor inner ring, but are not absolutely necessary on the stator inner ring. In the embodiment of FIG. 4, the bars and grooves in the inner ring are angled relative to the radius, thereby inhibiting free centrifugal flow in the inner ring and increasing retention time, if rotated to the left, or accelerating the flow if rotated to the right. In the embodiment of FIG. 6, inner rings 162A and 162B have a substantially radial orientation that neither inhibits or nor enhances centrifugal flow. As shown in FIGS. 3 and 5, the bars at the inlet of the defibrating region, e.g. the outer region of the inner rings, have a long chamfer 164, or a gradual wedge closing shape. In general, the entrance to the fiberizing gap 156 between the inner rings is radial or near radial (no significantly scattered transition). This also prevents strong impacts on the wood chips. The slope of the chamfer should be typically a drop of 5 mm in height over a radial distance of 15-50 mm. The resulting slope is 1:5 to 1:10, but slopes of 1:3-1:15 with height drop of 3 to 10 mm are acceptable. It is that wedge shape that defines the low intensity “peeling” of chips, as opposed to the high intensity impacts of conventional breaker bars operating at a tight gap. The operating gap 156 in the working region of the inner plate be in the order of 1.5-4.0 mm, and can narrow gently outwardly. If the chamfer 164 is in the lower range of the angle (e.g. 1:3), then a large taper of gap 156 should be used, e.g., at least 1:40. This will ease the feed into the tighter gap. The short working region 110 should operate at a gap of between 3 and 5 mm when the outer rings are at a standard operating gap. The gap 158 at the inlet of the outer rings should be slightly larger than the gap at the outer part of the inner rings. The outer part of the inner ring is preferably ground with taper, which ranges from flat to approximately 2 degrees, depending on application. Larger tapers and larger operating gaps will reduce the amount of work done in the inner rings. The construction of the outer region of the inner ring is such that it should minimize impact on the feed material in order to preserve fiber length at a maximum, while properly separating fibers. The groove width in the fibrating region 110 should be smaller than the wood particles, and in order of magnitude of minimum operating gap for the fibrating region. Typically, no groove should be wider than 4 mm wide. This ensures that wood particles are being treated in the gap rather than being wedged between bars and hit by bars from opposing disc. In the fibrating inner region 110 (or plate inlet for a one-piece refiner plate), the chips are reduced to fibers and fiber bundles before passing through annular space 160 and entering the outer ring 104. That ring can closely resemble known high consistency refiner plate construction. As the fibers are mostly separated, they will not be subjected to high intensity impacts. One can see from FIGS. 3 and 5 that if untreated chips could enter the feeder region 108 of the outer ring, they would be subjected to high intensity impacts when the chip is wedged between two coarse bars 118, 120. If the chips are properly separated in the fibrator inner rings 102, then there are no large particles left, so they cannot be subjected to this type of action. The division of functionality as between the inner and outer rings can also be implemented in a so-called “conical disc”, which has a flat initial refining zone, followed by a conical refining zone within the same refiner. In that case, the inventive fibrating rings would substitute for the flat refining zone, which would then be followed by the conventional “main plate” refining in the conical portion. Normally, a conical portion for such refiners has a 30 or 45 degree angle cone, e.g. it is 15 or 22.5 degrees from a cylindrical surface. An example of such a conical disc refiner is described in U.S. Pat. No. 4,283,016, issued Aug. 11, 1981. Thus, as used herein, “disc” includes “conical disc” and “substantially radially” includes the generally outwardly directed but angled gap of a conical refiner. The inlet of the outer region of inner ring has a radial transition, or close to radial. Large variation in the radial location of the start of the ground surface normally results in the loss of fiber length, when particles larger than the gap are quickly forced into the gap. With a long chamfer at the start of the region (longer is better), the material fed will be gradually reduced in size until small enough (coarseness reduction) to enter the gap formed by the ground surfaces. The groove width of the outer region of the inner ring has to be narrow enough to prevent large unsupported fiber particles from entering the groove and then be forced into the gap, thus causing fiber cutting. Typically, the groove width should be no wider than the gap at the inlet of the ground surface. Subsurface dams or surface dams can be used in order to increase the efficiency of the action and/or increase energy input in the inner plates. Two embodiments of the outer, fibrillating ring are shown in FIGS. 7 and 8. These can range from high intensity to very low intensity. For the purpose of illustration of the concept, the pattern of FIG. 7 is a typical example of a high intensity directional outer ring 166. FIG. 8 represents a very low intensity bi-directional design 182. Various other bar/groove configurations can be used, such as having a variable pitch (see U.S. Pat. No. 5,893,525). The directional ring 166 is coarser and has a forward feeding region 172 which reduces retention time and energy input capability in that area, forcing more energy to be applied in the outer part of the ring, which in turn increases the intensity of the work applied there, and thus will operate at a tighter gap. The working region of the outer ring has two zones 168, 170, the outer 168 of which has finer grooves than the former 170. Some or all of the grooves such as 176 in the zone 168 can define clear channels that are slightly angle to the true radii of the ring, whereas other grooves such as 180 in the other zone 170 can have surface or subsurface dams 174, 178. Overall, the outer ring 166 is similar to the outer ring 112 of FIG. 3. As another example, the full-length variable pitch pattern 182 of FIG. 8 has essentially radial channels, without any centrifugal feeding angle. The feed region 190 is very short, and the working region 188 can have uniform or alternating groove width, or as shown at 184 and 186, alternating or variable groove depth. This allows for a longer retention time within the plates and, combined with the large number of bar crossings, allows for a low intensity of energy transfer, which results in a larger plate gap. In a variation of the outer ring, the inner feeding region of the outer ring is designed to prevent backflow of fiber from the outer ring to the inner ring. FIG. 8D presents an outer ring 192 for the rotor disc, with a feed region 194 having curved feeding bars 195. The opposing stator ring 196, as illustrated in FIG. 8E, does not have bars in the inner feed region 198 in opposition to the curved bars, thereby accommodating the opposing curved feeding bars 195 on the outer ring 192. Such an approach further ensures a complete separation between the defibration and fibrillation steps in the inner and outer rings, respectively. As shown in figures, the curved feeding (injector) bars 195 can optionally be supplemented with other structure in the feeding region of the rotor and/or stator rings (such as pyramids and opposed radial bars) to aid in the distribution of material from the curved bars into the working region. Thus, the surface of the radial extent of feed region 194 of the rotor can be fully or partially occupied by projecting curved bars 195 and the surface of the radial extent of the feed region 198 of the stator can be entirely flat, or partially occupied by distribution structure. The curved bars 195 of the rotor ring project in the feed region 194 a distance greater than the height of the bars in the working region, but the flatness of the opposed surface in the feeding region 198 of the stator ring accommodates this greater height. In general, the pattern of bars and grooves throughout the working region of the inner ring has a has a first average, preferably uniform, density and the pattern of bars and grooves throughout the feed region of the outer ring has a second average, preferably uniform but lower density. 2. Pilot Plant Laboratory Realization The combination of fiberizing inner rings and high-efficiency outer rings is therefore an important component of this process. The optimization of this process was conducted by running an Andritz pressurized 36-1CP single disc refiner in two steps, firstly using only inner plates and secondly using only the outer plates. For the inner plates, a special Durametal D14B002 three zone refiner plate was used with ½ of the outer intermediate zone and the entire outer zone ground out (see FIG. 9). The inner ½ of the intermediate zone is used to fiberize the destructured wood chips. For the outer plate, a Durametal 36604 directional refiner plate was used in both feeding (expel) and restraining (holdback) refining configurations (see FIG. 10). Three refining configurations were run using the fiberizer plate inners to simulate the following process variations: 1. RT [2-3 sec. retention (i), 85 psig, 1800 rpm] ii) See A1 from data tables. 2. RTS [2-3 sec. retention (i), 85 psig, 2300 rpm] ii). See A2 from data tables. 3. TMP [2-3 sec. retention (i), 50 psig, 1800 rpm] iii). See A3 from data tables. i) Retention from PSD discharge to refiner Inlet. ii) Steaming Tube Pressure=5 psi, retention=30 seconds. iii) Steaming Tube Pressure=20 psi, retention=3 minutes. The precursor used to represent the combination of MPSD destructuring and fiberizing inner plates is f-. Therefore the nomenclature used for the preceding configurations are: 1) f-RT 2) f-RTS 3) f-TMP The fiberized (f) material was then refined using the refiner plate outers at similar respective conditions of pressure and refiner speed i.e. 1) f-RT outers: 85 psig, 1800 rpm 2) f-RTS outers: 85 psig, 2300 rpm 3) f-TMP outers: 50 psig, 1800 rpm The majority of the specific energy was applied during the refiner outer runs. Different conditions of refiner plate direction (expel and holdback) and applied power were evaluated during the outer runs in this investigation. Each of the primary refined pulps was then refined in a secondary atmospheric Andritz 401 refiner at three levels of applied specific energy. Control TMP series were also produced without destructuring of the wood chips in the PMSD. This was accomplished by decreasing the production rate of the inners control run from 24.1 ODMTPD to 9.4 ODMTPD. This effectively reduced the plug of chips in the PMSD. The plates were backed off during the control inners run such that size reduction was accomplished using only the breaker bars i.e., no effective refining action by the refiner fiberizing bars following the breaker bars. The inners chips were then refined in the 36-1CP refiner using the outers plates. The primary refined pulps were then refined in the Andritz 401 refiner at several levels of specific energy. TABLE A presents the nomenclature for each of the refiner series produced in this trial study. The corresponding sample identifications are also presented. TABLE A Sample Identification Primary Primary Nomenclature* Inners Outers Secondary f-RT 1800 hb 485 ml A1 A4 A7, A8, A9 f-RT 1800 ex 663 ml A1 A5 A10, A11, A12 f-RT 1800 ex 661 ml A1 A6 A13, A14, A15 f-RT 1800 ex 460 ml A1 A16 A22, A23, A24 f-RT 1800 ex 640 ml A1 A17 A25, A26, A27 (2.8% NaHSO3) f-RT 1800 hb 588 ml A1 A18 A28, A29, A30 f-RTS 2300 ex 617 ml A2 A19 A31, A32, A33 f-RTS 2300 ex 538 ml A2 A20 A34, A35, A36 (3.1% NaHSO3) f-TMP 1800 ex 597 ml A3 A21 A37, A38, A39 f-TMP 1800 hb 524 ml A3 A41 A46, A47, A48 TMP 1800 hb 664 ml A3-1 A44 A54, A55, A56, A57, A58 TMP** 1800 hb 775 ml A3-1 A43 A49, A50, A51, A52, A53 *Nomenclature = process, 1ry refiner speed (1800 rpm or 2300 rpm), 1ry outers configuration (ex or hb), 1ry refined freeness **No good since primary refiner freeness was too high. The refiner series produced with the primary outers in holdback had a larger plate gap and higher long fiber content than the respective series produced using expelling outers. This permitted refining the holdback series to lower primary freeness levels while retaining the long fiber content of the pulp. FIGS. 11-18 illustrate pulp property results for most of the refiner series produced in this investigation. The two series produced at very low primary freeness (<500 ml) are excluded from the plots due to congestion. FIG. 11. Freeness Versus Specific Energy The control TMP series had the highest specific energy requirements to a given freeness. The f-TMP series had the next highest energy requirements followed by the f-RT series. The f-RTS series had the lowest specific energy requirements to a given freeness. TABLE B compares the specific energy requirements for each of the plotted refiner series at a freeness of 150 ml. The results are from linear interpolation. TABLE B Specific Energy at 150 ml. Specific Energy (kWh/MT) f-RT 1800 ex 661 ml 1889 f-RT 1800 hb 588 ml 1975 f-RTS 2300 ex 617 ml 1626 f-TMP 1800 ex 597 ml 2060 f-TMP 1800 hb 524 ml 2175 TMP 1800 hb 664 ml 2411 f-RT 1800 ex 640 ml (2.8% NaHSO3) 2111* f-RTS 2300 ex 538 ml (3.1% NaHSO3) 1411* *By extrapolation. The f-RTS 2300 ex series (combination of fiberizing, RTS, and high intensity plates) had a 32% lower energy requirement than the control TMP series to freeness of 150 ml. The f-RT 1800 hb and f-RT 1800 ex series had 18% and 22%, respectively, lower energy requirements than the control TMP series at 150 ml. The f-TMP hb and f-TMP ex series had 10% and 15%, respectively, lower energy requirements than the control TMP series. The results indicate that rebuilding/replacing the PSD and refiner plates can generate a substantial return on investment for existing TMP systems. FIG. 12. Tensile Index Versus Specific Energy The f-RTS ex pulps had the highest tensile index at a given application of specific energy, followed by the f-RT series and then the f-TMP series. The control TMP pulps had the lowest tensile index at a given application of specific energy. The addition of approximately 3% sodium bisulfite (NaHSO3) solution to the PSD discharge increased the tensile index relative to the respective series without chemical treatment. A 52.5 Nm/g tensile index was achieved with the f-RTS 2300 ex (3.1% NaHSO3) series with an application of 3.1% NaHSO3 and 1754 kWh/ODMT. FIG. 13. Tensile Index Versus Freeness Non-Chemically Treated Series There were two bands of tensile index results. The lower band represents the series produced using the expelling outer plates. The upper band represents the series produced using the holdback outer plates. The average increase in tensile index using the holdback plates was approximately 10%. It is noted that an f-RTS hb series was not conducted in this trial due to a shortage of fiberized A3 material. Bisulfite Treated Series The addition of approximately 3% bisulfite to the f-RT ex and f-RTS ex series elevated the tensile index to a similar or higher level than the holdback pulps. TABLE C compares each of the refiner series at a freeness of 150 ml. The regression equations used in the interpolations are included on FIG. 13. TABLE C Tensile Index at 150 ml Tensile Index (Nm/g) f-RT 1800 ex 661 ml 43.8 f-RT 1800 hb 588 ml 47.7 f-RTS 2300 ex 617 ml 42.4 f-TMP 1800 ex 597 ml 43.5 f-TMP 1800 hb 524 ml 48.1 TMP 1800 hb 664 ml 48.2 f-RT 1800 ex 640 ml (2.8% NaHSO3) 47.0* f-RTS 2300 ex 538 ml (3.1% NaHSO3) 47.9* *By extrapolation. FIG. 14. Tear Index Versus Freeness The refiner series produced using holdback outer plates had the highest tear index and long fiber content. TABLE D compares the refiner series at a freeness of 150 ml. The tear index values were obtained using linear interpolation. TABLE D Tear Index at 150 ml Tear Index (mN · m2/g) f-RT 1800 ex 661 ml 9.0 f-RT 1800 hb 588 ml 9.9 f-RTS 2300 ex 617 ml 8.7 f-TMP 1800 ex 597 ml 8.6 f-TMP 1800 hb 524 ml 9.3 TMP 1800 hb 664 ml 9.1 f-RT 1800 ex 640 ml (2.8% NaHSO3)* 9.7 f-RTS 2300 ex 538 ml (3.1% NaHSO3)* 8.8 *By extrapolation. The f-RT hb pulps had the highest tear index. The f-RT ex and f-RTS ex pulps had comparable tear index results FIG. 15. Burst Index Versus Freeness The f-RT 1800 hb and f-TMP 1800 hb series produced with holdback outer plates had the highest burst index at a given freeness. The refiner series produced with expelling outer plates, f-RT 1800 ex, f-TMP 1800 ex, f-RTS 2300 ex, had a lower burst index at a given freeness. The addition of approximately 3% bisulfite increased the burst index of the series produced with expelling outer plates to a similar level as the non-chemically treated series produced with holdback outer plates. TABLE E compares the burst index results interpolated to a freeness of 150 ml. TABLE E Burst Index at 150 ml Burst Index (kPa · m2/g) f-RT 1800 ex 661 ml 2.51 f-RT 1800 hb 588 ml 2.85 f-RTS 2300 ex 617 ml 2.30 f-TMP 1800 ex 597 ml 2.38 f-TMP 1800 hb 524 ml 2.76 TMP 1800 hb 664 ml 2.45 f-RT 1800 ex 640 ml (2.8% NaHSO3)* 2.98 f-RTS 2300 ex 538 ml (3.1% NaHSO3)* 2.67 *By extrapolation. FIG. 16. Shive Content Versus Freeness The control TMP pulps had the highest shive content levels. The refiner series produced with the expelling outer plates had lower shive content levels than the respective series produced with holdback outer plates. It was clearly evident that the f-pretreatment helps reduce shive content. TABLE F compares the shive content levels for each refiner series interpolated to a freeness of 150 ml. TABLE F Shive Content at 150 ml. Shive Content (%) f-RT 1800 ex 661 ml 0.70 f-RT 1800 hb 588 ml 1.35 f-RTS 2300 ex 617 ml 0.31 f-TMP 1800 ex 597 ml 0.37 f-TMP 1800 hb 524 ml 1.61 TMP 1800 hb 664 ml 2.63 f-RT 1800 ex 640 ml (2.8% NaHSO3)* 0.59 f-RTS 2300 ex 538 ml (3.1% NaHSO3)* 0.18 *By extrapolation. The f-RTS ex series produced with and without bisulfite addition had the lowest shive content levels. The addition of bisulfite lowered the shive content. FIG. 17. Scattering Coefficient Versus Freeness The refiner series produced with the expelling outer plates had the highest scattering coefficient levels. TABLE G presents the scattering coefficient results for each series at a freeness of 150 ml. TABLE G Scattering Coefficient versus Freeness Scattering Coefficient (m2/kg) f-RT 1800 ex 661 ml 57.1 f-RT 1800 hb 588 ml 55.1 f-RTS 2300 ex 617 ml 56.8 f-TMP 1800 ex 597 ml 56.3 f-TMP 1800 hb 524 ml 53.6 TMP 1800 hb 664 ml 54.4 f-RT 1800 ex 640 ml (2.8% 55.9 NaHSO3)* f-RTS 2300 ex 538 ml (3.1% 53.8 NaHSO3)* *By extrapolation. The addition of approximately 3% bisulfite reduced the scattering coefficient by approximately 1-3 m2/kg. FIG. 18. Brightness Versus Freeness All the f-series had higher brightness than the control TMP pulps. TABLE H compares each of the refiner series interpolated to a freeness of 150 ml. TABLE H ISO Brightness at 150 ml ISO Brightness f-RT 1800 ex 661 ml 52.0 f-RT 1800 hb 588 ml 51.3 f-RTS 2300 ex 617 ml 52.8 f-TMP 1800 ex 597 ml 49.4 f-TMP 1800 hb 524 ml 48.9 TMP 1800 hb 664 ml 47.3 f-RT 1800 ex 640 ml (2.8% NaHSO3)* 56.5 f-RTS 2300 ex 538 ml (3.1% NaHSO3)* 59.1 *By extrapolation. The f-TMP series had approximately 2% higher brightness than the control TMP series. A higher removal of wood extractives from the high compression PSD component of the f-pretreatment most probably contributed to the brightness increase. The f-RTS series had the highest brightness (52.8) followed by the f-RT series (average=51.7), then the f-TMP series (average=49.2). The addition of 3% bisulfite increased the brightness considerably, up to 59.1 with the f-RTS ex series. 3. Comparing Defibration Conditions During Inner Zone Refining TABLE I compares the fiberized properties following the inner plates. As indicated earlier, three fiberizer runs, A1, A2, A3 were conducted to simulate the f-RT, f-RTS and f-TMP configurations. Each of these inner ring runs was fed with destructured chips from the PSD. TABLE I Fiberized Properties following Inner Rings Specific Energy Shive +28 Fiberizer Pressure Throughput (kWh/ Content Mesh (f-) Run Process (psi) (ODMTPD) ODMT) (%) (%) A1 RT 85 23.3 152 66.5 75.4 A2 RTS 85 23.3 122 35.6 79.4 A3 TMP 50 24.1 243 88.7 82.4 It is evident that the process conditions have a major impact on the defibration efficiency during inner zone refining. The destructured chips refined at higher pressure (A1, A2) had a significantly lower shive content (=more defibrated fibers) compared to refining at a typical TMP pressure (50 psi). The energy requirement for defibration was also lower at high pressure. The highest defibration level was obtained when combining high pressure and high speed (A2). The A2 (f-RTS) material demonstrated the highest fiber separation, followed by the A1 (f-RT) material. The A3 (f-TMP) was clearly the coarsest of the fiberized samples. It is noted that bar directionality was not a factor during the inner zone refining runs since the inner plates were bidirectional. The energy for defibration decreases with an increase in pressure. The energy losses are quite substantial when defibrating at conventional conditions. For example, at a pressure of 50 psig, an additional specific energy requirement of well over 100 kWh/MT would be necessary when producing fiberized material to the same shives level as compared to refining at 85 psig. 4. Laboratory Procedures White spruce chips from Wisconsin were used for these examples. Material identification, solids content and bulk density for the spruce chips appear in TABLE II. Initially, several runs were carried out on the 36-1CP pressurized variable speed refiner utilizing plate pattern D14B002 with the outer zone and ½ intermediate zone ground out. This was conducted to simulate the inner rings of larger single disc refiners. The first run A1 was produced with 30-second presteam retention in the steaming tube at 0.4 bar, 5.87 bar refiner casing pressure, and a machine speed of 1800 rpm. For A2, the machine speed was increased to 2300 rpm. The A3 run was produced with 3 minutes presteam retention at 1.38 bar, 3.45 bar refiner casing pressure, and refiner disc speed of 1800 rpm. Run A3-1 was also conducted at similar conditions as A3, except the production rate was decreased from 24.1 ODMTPD to 9.4 ODMTPD in order to prevent destructuring of the chips prior to feeding the refiner. The plate gap for this run was also increased to eliminate any effective action by the intermediate bar zone, such that the chips received breaker bar treatment only. Fiber quality analysis was not possible on sample A1-1 since chips receiving breaker bar treatment only are not in a fiberized form; therefore shive or Bauer McNett analysis is not applicable. Each of these pulps was used to produce additional series. Six series were carried out on the A1 material. The outer plates (Durametal 36604) were installed in the 36-1CP refiner to simulate the outer zone of refining. All six primary outer zone runs were refined on the 36-1CP at 5.87 bar casing pressure and at a disc speed of 1800 rpm. The process nomenclature for these runs is RT. A sodium bisulfite liquor was added to A17 resulting in a chemical charge of 2.8% NaHSO3 (on O.D. wood basis). Three secondary refiner runs were produced on each series. Two series were produced on the A2 material. Both 36-1CP outer zone runs produced (A19 and A20) were produced at 5.87 bar refiner casing pressure and 2300 rpm machine speed. The process nomenclature for these runs is RTS. Sodium bisulfite liquor was added to A20 (3.1% NaHSO3). Again three secondary refiner runs were produced on each. Several series were also produced on the A3 material, each at 3.45 bar refiner casing pressure and 1800 rpm. Three secondary refiner runs were produced on each. The process nomenclature for these runs is TMP. Many of the secondary 36-1 CP refiner runs were produced in reverse mode, which is indicated in TABLE IV. Two control TMP series were produced (A43 and A44) on the A3-1 chips, which went through breaker bar treatment only during inner zone refining. Both A43 and A44 were refined at 3.45 bar steaming pressure and 1800 rpm machine speed. Several atmospheric refiner runs were then conducted on these pulps to decrease the freeness to a comparable range as the earlier produced series. All pulps were tested in accordance to standard Tappi procedures and in compliance with Andritz Inc. Business Rules where applicable. Testing included Canadian Standard Freeness, Pulmac Shives (0.10 mm screen), Bauer McNett classifications, optical fiber length analyses, physical and optical properties. This information appears in TABLE III. TABLE I-A GRAPHIC RUN SUMMARY NOTE: A1 USED D14B002 PLATES- OUTER TAPER AND 1/2 INTERMEDIATE ZONE AND OUTER ZONE GROUND OUT. A1 TUBE PRESSURE OF 0.69 BAR, A4, A5, A6, A16, A17 and A18 TUBE PRESSURE 0.34 BAR. A5, A6, A16 and A17 REFINED IN REVERSE MODE. TABLE I-B GRAPHIC RUN SUMMARY NOTE: A2 AND A3 USED D14B002 PLATES OUTER TAPER AND 1/2 INTERMEDIATE ZONE AND OUTER ZONE GROUND OUT. A2 TUBE PRESSURE OF 0.69 BAR, A3 TUBE PRESSURE 1.38 BAR. A19, A20, A32, A40, A41 and A42 TUBE PRESSURE 0.34 BAR. A19, A20, A21 REFINED IN REVERSE MODE. TABLE I-C GRAPHIC RUN SUMMARY TABLE II MATERIAL IDENTIFICATION BULK DENSITY (kg/m3) MATERIAL % O.D. SOLIDS WET DRY 01 SPRUCE 66.5 169.8 112.9 SOAKED 47.7 | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to apparatus and method for thermomechanical pulping of lignocellulosic material, particularly wood chips. In recent decades, the quality of mechanical pulp produced by thermomechanical pulping (TMP) techniques has been improving, but the rising cost of energy for these energy-intensive techniques imposes even greater incentives for energy efficiency while maintaining quality. The present inventor has already advanced the state of the art as embodied in the Andritz RTS™, RT Pressafiner™, and RT Fibration™, process technologies. He discovered an operating window by which feed material is preheated for a very short residence time at high temperature and pressure, then refined at such high temperature and pressure between opposed discs rotating at high speed. (U.S. Pat. No. 5,776,305). A further improvement was directed to pretreating the feed chips before preheating, by conditioning in a pressurized steam environment and compressing the conditioned chips in the pressurized steam environment. (PCT/US98/14718). Yet another improvement is disclosed in International Application PCT/US2003/022057, where the feed chips discharged from the pretreatment step, are fiberized without fibrillation, for example with a low intensity refiner, before delivery to a high intensity refiner. The underlying principle in the progression of the foregoing developments has been to distinguish and handle in distinct equipment, the axial fiber separation and fiberization of the chip material, from the fibrillation of the fibers to produce pulp. The former steps are performed in dedicated equipment upstream of the refiner, using low energy consumption that matches the relatively low degree of working and fiber separation, while the high energy consuming refiner is relieved of the energy-inefficient defibering function and can devote all the energy more efficiently to the fibrillation function. This is necessary since the fibrillation function requires even more energy than defibering (also known as defibration) These developments did indeed improve energy efficiency, especially in systems that employ high-speed discs (i.e., above 1500 rpm for double disc and above 1800 rpm for single disc refiners). However, especially for systems that did not employ high-speed refiners, the long-term energy efficiency was offset to some extent in the short term by the need for more costly or more space-occupying equipment upstream of the primary refiner. | <SOH> SUMMARY OF THE INVENTION <EOH>The object of the invention is to provide a simplified system and method for producing high quality thermomechanical pulps at lower energy consumption. The simplification includes facilitating the supply of lower cost systems capable of accelerated commissioning and start-up. In essence, the invention achieves significant energy efficiency, even in systems that do not employ a high speed refiner, while reducing the scope and complexity of the equipment needed upstream of the refiner. This object is achieved by synthesizing the concepts underlying the RTS, RT Pressafiner, and RT Fibration process technologies, and using a simplified equipment train. The equipment for implementing the invention requires only a pressurized screw discharger (PSD) and refiner(s). Significant modifications, however, are required to the PSD and the associated refining process. The PSD is of the destructuring variety (macerating pressurized screw discharger, or MPSD) with increasing root diameter and plug zone complete with blowback valve (BBV). MPSD inlet pressure may span from atmospheric to about 30 psig, preferably 5-25 psig. This component of the process simulates RT Pressafiner pretreatment. Higher dilution flow is necessary to maintain nominal refining consistencies, since the MPSD dewaters to higher solids content than conventional PSD screws. Fiberizing inner plates (inner rings) in the primary refiner are designed to effectively feed and fiberize destructured wood chips. This component of the process is used to simulate RT Fibration. High-efficiency outer plates (outer rings) in the primary refiner are designed for feeding (high intensity =>minimum energy consumption) or restraining (low intensity =>maximum strength development), or intensity levels between the two extremes, depending on product quality and energy requirements. In a broad aspect, the invention is directed to a method for thermomechanical refining of wood chips comprising exposing the chips to an environment of steam to soften the chips, macerating and partially defibrating the softened chips in a compression device, feeding the destructured and partially defibrated chips to a rotating disc primary refiner, wherein opposed discs each have an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves, a substantially completing fiberization (defibration) of the chips in the inner ring and fibrillating the resulting fibers in the outer ring. The system implementation preferably includes an inner feeding region and an outer working region on the inner ring and an inner feeding region and an outer working region on the outer ring, wherein the working region of the inner ring is defined by a first pattern of alternating bars and grooves, and the feeding region of the outer ring is defined by a second pattern of alternating bars and grooves. The first pattern on the working region on the inner ring has relatively narrower grooves than the grooves of the second pattern on the feeding region on the outer ring. The fiberization of the chips is substantially completed in the working region of the inner ring with low intensity refining, while the fibrillation of the fibers is performed in the working region of the outer ring at a smaller plate gap and higher refining intensity. The inventive method preferably comprises the steps of exposing the chips to an environment of steam to soften the chips, compressively destructuring and dewatering the softened chips to a consistency greater than about 55%, diluting the destructured and dewatered chips to a consistency in the range of about 30% to 55%, feeding the diluted destructured chips to a rotating disc refiner, where opposed discs each have an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves, fiberizing (defibrating) the chips in the inner ring, and fibrillating the resulting fibers in the outer ring. The compressive destructuring, dewatering, and dilution can all be implemented in one integrated piece of equipment immediately upstream of the primary refiner, and the fiberizing and fibrillating are both achieved between only one set of relatively rotating discs in the primary refiner. The new, simplified TMP refining method, combining a destructuring PSD and fiberizing inner plates, was shown to effectively improve TMP pulp property versus energy relationships relative to conventional TMP pulping. The method improved the pulp property/energy relationships for three commercially available processes: TMP, RT, and RTS. The RT and RTS refining configurations refer to low retention and higher pressure refining, typically between 75 psig and 95 psig, at standard refiner disc speeds (RT) or higher disc speeds (RTS). The defibration efficiency of the inner refining zone improved at higher refining pressure. The level of defibration further increased with an increase in refiner disc speed. Thermomechanical pulps produced with holdback outer rings had higher overall strength properties compared to pulps with expelling outer rings. The latter configuration required less energy to a given freeness and had lower shive content. The specific energy savings to a given freeness using the inventive method in combination with expelling outer plates was 15%, 22%, and 32% for the TMP, RT, and RTS series, respectively, compared to the control TMP pulps. Combining the inventive method with bisulfite treatment improved pulp strength properties and significantly increased pulp brightness. Higher dilution flow effectively compensated for the higher discharge solids exiting the MSD-type PSD. The dilution/impregnation apparatus should ensure thorough penetration of the chips exiting the MPSD. One option is a split dilution strategy that adds dilution to both the MPSD discharge and in-refiner. In the present context, maceration should be understood as the physical mechanism associated with solid material under compressive shearing forces. Maceration of wood chips in a steam-pressurized screw device or the like, destructures the material without breakage across grain boundaries, resulting in significant but not complete (e.g., up to about 30%) axial separation of the fibers. The majority of the maceration occurs in the plug zone after the flights, but some initial maceration can occur in the flighted section before the plug zone. The restriction in the plug zone can increase compression and maceration to some degree in the earlier flighted section. Impregnation liquid (water and/or chemicals) is added directly in the expansion region or chamber at the discharge of the macerating screw device such that the liquid uptake into the expanding wood structure is immediate. The destructured wood chips should be sufficiently saturated with liquid such that the refining consistency is in a preferable range for optimum pulp. All or most of the liquid uptake takes place at the discharge of the MPSD as the heavily compressed chips are released. In the alternative embodiment, the dilution liquid is split, with some dilution at the MPSD screw discharge and further dilution introduced between the inner and outer refiner rings. The latter configuration is useful when excessive saturation is observed at the MPSD discharge but additional dilution is beneficial (after the inner rings) to further optimize the fibrillation refining. As an example but not a limitation, the consistency in the plug-pipe zone is typically in the range of 58%-65%, and in the expansion zone with impregnation/dilution, in the range of about 30%-55%. The material remains at this consistency range through the seal off zone of the BBV (which is not normally a full seal and is thus similar in pressure to the expansion zone), at the exit from the seal off zone, and at the inlet to the refiner ribbon feeder. This is a pressurized environment so vaporization is taking place, but the goal is to target the optimum refining consistency, usually around 35%-55%, as delivered to the refiner feed device for introduction between the refiner plates. In most cases the bar/grooves in the working zone of the outer rings (fibrillation) must be finer than in the working zone of the inner rings (defibration). To produce a mechanical pulp fiber, the fiber must first be defibrated (separated from the wood structure) and then fibrillated (stripping of fiber wall material). A key feature of this invention is that the working zone of the inner rings primarily defibrates and the working zone of the outer rings primarily fibrillates. A significant aspect of the novelty of the invention is maximizing the separation of these two mechanisms in a single machine and by that more effectively optimizing the fiber length and pulp property versus energy relationships. Since defibration in the inner rings takes place on relatively large destructured chips, the associated working region pattern of bars and grooves cannot be too fine. Otherwise the destructured chips would not adequately pass through the grooves of the inner rings and be distributed evenly. The defibrated material as received in the outer ring feed region from the inner ring and distributed to the outer ring working region, is relatively smaller and thus the pattern of bars and grooves in the working region of the outer ring is finer than in the inner ring. Another benefit of the invention is that more even distribution (i.e., higher fiber coverage across refiner plates) occurs both in the inner rings and outer rings compared to conventional processes. Better feeding means better feed stability, which decreases refiner load swings, which in turn helps maintain more uniform pulp quality. An important benefit of the present invention is that the retention time is minimized at each functional step of the process. This is possible because the fibrous material is sufficiently size reduced at each step in the process such that the operating pressures can almost instantaneously heat and soften the fiber to the required level. The process can be considered as having three functional steps: (1) producing destructured chips, (2) defibrating the destructured chips, and (3) fibrillating the defibrated material. The equipment configuration should establish minimum retention time from the MPSD discharge of step (1) to the refiner inlet. The refiner feed device (e.g., ribbon feeder or side entry feeder) operates almost instantaneously for initiating step (2) in the inner rings. The inner ring design should establish a retention time for the material to pass through uninhibited. Some inner ring designs may have longer residence than others to effectively defibrate, but the net retention time is still less than if fibration were performed in a separate component. The defibrated material passes almost instantaneously to the outer ring where step (3) is achieved. Here also, the retention time is low. The actual retention time in the outer ring will be dictated by the design of plates chosen to optimize pulp properties and energy consumption. The benefit of this very low retention (minimum) at each process step (while achieving necessary fiber softening for maintaining pulp strength properties) is maximum optical properties. In the system described in my prior International Application PCT/052003/022057, wherein the destructured chips were defibrated in a smaller fiberizer refiner before delivery to the main, primary refiner for fibrillation, the pressures were much lower in the fiberizing (defibration) step. The fiberizing retention time at pressure was much longer in a completely separate refiner. It was desirable to maintain a lower temperature to help preserve pulp brightness, since the low intensity refining intensity was gentle. High temperatures were therefore neither necessary nor desirable in the separate fiberizing refiner to preserve pulp strength. In the present invention, defibration and fibrillation are performed within the same highly pressurized refiner casing. The refining intensity in the fiberizing (defibrating) inner ring is still low, achieved at high pressure and a low retention time. There is no negative impact on brightness despite the high pressure (temperature), because the retention time is so short. This is analogous to the surprisingly beneficial effect of low preheat retention time at high temperature as described in my U.S. Pat. No. 5,776,305 (RTS mechanism). When the present invention is implemented in an RTS system, there is no need for a separate preheat conveyor immediately upstream of the refiner feed device, because the destructured chips heat up rapidly during normal conveyance from the MPSD to the refiner. The environment from the expansion volume or chamber to the rotating discs is the refiner operating pressure, e.g., 75 to 95 psig for RTS, and the “retention time” at the corresponding saturation temperature during conveyance between the MPSD and refiner is well under 10 seconds, preferably in the range of 2-5 seconds, corresponding to the preferred RTS preheat retention time. More generally, the process advantage of achieving energy efficient production of quality TMP pulp with minimum time at each process step, has the corollary advantage of minimizing the component, space, and cost requirements of equipment for implementing the process. Almost any installed TMP, RT-TMP, or RTS-TMP system can be upgraded according to at least some aspects of the present invention, without increasing the equipment footprint in the mill. | 20040708 | 20071127 | 20060112 | 60281.0 | B02C704 | 0 | HUG, JOHN ERIC | ENERGY EFFICIENT TMP REFINING OF DESTRUCTURED CHIPS | UNDISCOUNTED | 0 | ACCEPTED | B02C | 2,004 |
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10,888,176 | ACCEPTED | Apparatus and method for determining strength of impact when closing a folder-type terminal | An apparatus and method for determining the strength of impact of closing the folder portion of a folder-type terminal are disclosed. When closing of the folder portion is detected, the impact force generated when the folder portion contacts the main body portion is measured, the relative strength of the measured impact force is determined, and an output corresponding to the measured impact force is generated. | 1. An apparatus for sensing the impact of closing the folder portion of a folder-type device having a folder portion and main body portion, comprising: detecting means that determines when the folder portion of the device is closed; measuring means that measures an impact when the folder portion is closed; output means; storage means that contains information regarding predetermined levels of impact force, the information corresponding to at least one level of folder portion closing strength, and output data corresponding to the at least one level of folder portion closing strength; and processing means that compares the impact measured by the measuring means to the information stored in the storage means to determine the folder portion closing strength and outputs the corresponding output data to the output means. 2. The apparatus of claim 1, wherein the detecting means detects closing of the folder portion when the main body and the folder portion narrows at a specific angle. 3. The apparatus of claim 1, the folder portion comprising a magnet and wherein the detecting means senses the magnetic force of the magnet in order to determine when the folder portion is closed. 4. The apparatus of claim 3, wherein the detecting means comprises a Hall effect device. 5. The apparatus of claim 1, the output data having an audio component and wherein the processing means and output means are adapted to provide an audio response to the closing of the folder portion. 6. The apparatus of claim 1., the output data having a visual component and wherein the processing means and output means are adapted to provide a visual response to the closing of the folder portion. 7. The apparatus of claim 1, the output data having both a visual and audio component and wherein the processing means and output means are adapted to provide both a visual and an audio response to the closing of the folder portion. 8. The apparatus of claim 1, wherein the output means comprises a speaker. 9. The apparatus of claim 1, wherein the output means comprises a display. 10. The apparatus of claim 1, the measuring means comprising a microphone, an amplifier, and a filter and wherein the recorded impact sound is converted to a DC level. 11. The apparatus of claim 10, wherein the filter is a low-pass filter. 12. The apparatus of claim 10, the processing means comprising an analog-digital converter and adapted to cause the measuring means to record the impact sound when the main body and the folder portion narrows at a specific angle, compare the recorded impact sound to the information regarding predetermined levels of impact force in the storage means, and retrieve the corresponding output data from the storage means. 13. An apparatus for sensing the impact of closing the folder portion of a folder-type device having a folder portion and main body portion, comprising: a detector for determining when folder portion is closed; an audio circuit for recording the impact sound when the folder portion is closed; a driving unit for controlling the audio circuit; a strength determining unit for determining the strength of the recorded impact sound; an output unit for conveying information corresponding to the measured strength of the impact sound; and a memory for storing output data and at least one predetermined level of folder portion closing impact strength, wherein the driving unit causes the audio circuit to record the impact sound when the detector determines a specific angle between the folder portion and main body portion. 14. The apparatus of claim 13, wherein the strength determining unit determines the strength of the impact sound by converting the recorded impact sound to a digital signal and comparing the digital signal with the at least one predetermined level of folder portion closing impact strength stored in the memory. 15. The apparatus of claim 13, wherein the output data is determined according to the at least one predetermined level of folder portion closing impact strength stored in the memory. 16. The apparatus of claim 13, wherein the detector comprises a Hall effect device. 17. The apparatus of claim 13, the audio circuit comprising a microphone, an amplifier, and a filter and wherein the recorded impact sound is converted to a DC level. 18. The apparatus of claim 17, wherein the filter is a low pass filter. 19. The apparatus of claim 13, wherein the strength determining unit comprises an analog-digital converter and is adapted to cause the audio circuit to record the impact sound when the main body and the folder portion narrow at a specific angle, compare the recorded impact sound to the at least one predetermined level of folder portion closing impact strength in the memory, and retrieve the corresponding output data from the memory. 20. The apparatus of claim 13, wherein the output unit comprises a speaker. 21. The apparatus of claim 13, wherein the output unit comprises a display. 22. A method for sensing for sensing the impact of closing the folder portion of a folder-type device having a folder portion and main body portion, comprising: detecting closure of the folder portion; measuring the impact force upon closure of the folder portion; determining the relative strength of the measured impact force; and generating an output according to the measured strength of the impact force. 23. The method of claim 22, further comprising detecting when the folder portion is at a specific angle with respect to the main body portion. 24. The method of claim 22, further comprising: powering an audio input circuit when closing of the folder portion is detected; and recording the impact sound through the audio input circuit. 25. The method of claim 24, further comprising: receiving the impact sound through a microphone; amplifying the received impact sound; and converting the amplified impact sound to a DC level through filtering. 26. The method of claim 22, further comprising: converting a DC level corresponding to the measured impact force to digital data; comparing the digital data to predetermined impact strength level digital information stored in a memory to determine the relative strength of the measured impact force; and determining the output corresponding to the relative strength of the measured impact force. 27. The method of claim 22, further comprising: retrieving audio and visual data corresponding to the measured impact force from a memory; transferring the retrieved audio data to an audio output unit; and transferring the retrieved visual data to display. | CROSS-REFERENCE TO RELATED APPLICATIONS Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to the Korean Application No. 57910/2003, filed on Aug. 21, 2003, the content of which is hereby incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a folder-type terminal and, more particularly, to an apparatus and method for determining the strength of impact when the folder portion of a folder-type terminal is closed and generating a display corresponding to the determined strength of impact. 2. Description of the Related Art As the use of mobile communications terminals has increased, the use of folder-type terminals has increased. Although such terminals have an advantage in that they are more compact and less bulky to store and carry, they also have disadvantages. One of the disadvantages is that users have experienced an increased occurrence of breakage in the folder portion of these terminals. One of the possible reasons for this breakage is that users tend to close the terminals with sufficient force to weaken and damage the apparatus attaching the folder portion to the main body portion of the terminal. Although it is known in the art to sense the opening and closing of a folder-type terminal, sensing the impact upon closing such a terminal would allow the user to determine if he or she is closing the terminal in a manner that may lead to damage to the folder portion. FIG. 1 illustrates one example of a conventional apparatus for sensing the closure of the folder portion of a folder-type terminal. The terminal 1 includes a folder portion 10 with a protrusion 11 at a certain position along the folder portion and a main body portion 20 having a contact switch 21 at a position where the protrusion contacts the main body portion. As illustrated in FIG. 1, the terminal 1 detects opening and closing of the folder portion 10 by a mechanical contact between the protrusion 11 and the contact switch 21. When the folder portion 10 is closed, the protrusion 11 of the folder 10 depresses the contact switch 21 of the main body portion 20 to cut off (or supply) a current flowing to the contact switch 21. Accordingly, the terminal 1 detects opening or closing of the folder 10 based on whether or not current flows at the contact switch 21. Although the terminal 1 illustrated in FIG. 1 can determine whether the folder portion 10 is open or closed, it can detect only the fully open or fully closed configuration, not the configuration where the folder portion 10 is in the process of closing. Furthermore, the terminal 1 illustrated in FIG. 1 cannot determine the force with which the folder portion 10 is closed. FIG. 2 illustrates another example of a conventional apparatus for sensing the closure of the folder portion of a folder-type terminal. The terminal 25 includes a folder portion 30 having a magnet 31 at a certain position along the folder portion and a main body portion 40 having a Hall effect switch 41 for sensing the magnetic field of the magnet of the folder portion. As illustrated in FIG. 2, the terminal 25 detects opening and closing of the folder portion 30 by using a Hall effect switching method. As the folder portion 30 is closed, the magnet 31 nears the Hall effect switch 41 of the main body portion 40. The Hall effect switch 41 senses the magnetic field of the magnet 31 and changes an output accordingly. A Mobile Station Modem (MSM) (not shown) of the main body portion 40 detects the change in the output of the Hall effect switch 41 and determines whether the folder portion 30 is open or closed. The terminal 25 illustrated in FIG. 2 may be able to determine the “imminent closure” configuration in addition to the fully closed and fully open configuration. However. The terminal 25 illustrated in FIG. 2 still cannot detect the force with which the folder portion 30 is closed. Therefore, there is a need for an apparatus that can determine not only the closing or opening of the folder portion of a folder-type terminal, but also the force with which the folder portion is closed. The present invention addresses this and other needs. SUMMARY OF THE INVENTION The present invention is directed to an apparatus and method for detecting the closure of the folder portion of a folder-type device and generating a display indicative of the strength of the impact of the folder portion against the main body portion. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention is embodied an apparatus for detecting the closure of the folder portion of a folder-type device. Specifically, an apparatus is provided that detects closure of the folder portion of a folder-type device, measures the impact of the closure, and generates a display to the user that is indicative of the strength of the impact. In one aspect of the invention, means are provided for detecting closure of the folder portion of a folder-type device, measuring the force with which the folder portion is closed, comparing the measured force with predetermined levels of force, and generating an output to inform the user of the force with which the folder portion was closed. The predetermined levels of force for comparison to the measured force as well as displays corresponding to each predetermined level of force are provided in a storage means. A processing means controls a detecting means, measuring means, output means, and storage means as well as performing the comparison of the measured impact to the predetermined levels of impact. The detecting means determines whether the folder portion is open or closed. It is contemplated that the detecting means may be adapted to determine when the folder portion is at a specific angle with respect to the main body portion of the device in order to activate the measuring means in time to measure the impact of the closure of the folder portion. Preferably, the detecting means includes a magnet in the folder portion and a sensor in the main body portion such that the magnetism of the magnet is sensed to determine when the folder portion is in proximity to the main body portion. The measuring means is adapted to measure the impact force when the folder portion contacts the main body portion. Preferably the measuring means includes a microphone for recording the impact sound, an amplifier for amplifying the recorded sound, and a filter, for example a low-pass filter, for converting the amplified sound to a DC level. The output means conveys to the user of the device the force with which the folder portion was closed in order to educate the user in the proper level of force with which to close the folder portion without damaging the device. It is contemplated that both an audible and visual message may be conveyed to the user. The storage means is adapted to store information regarding predetermined levels of folder portion closure impact force as well as corresponding messages to be conveyed to the user via the output means. It is contemplated that digital data corresponding to several different levels of folder portion closure impact force may be stored, for example levels corresponding to an acceptable closing force, a minimally acceptable closing force, and an unacceptable closing force. It is further contemplated that the predetermined levels of folder portion closure impact force may be determined based on the characteristics of the specific device for which the apparatus is used. The processing means controls the other means and performs the comparison of the impact force measured by the measuring means to the predetermined folder portion closure impact force levels stored on the storage means. It is contemplated that the processing means may be adapted to monitor the detecting means in order to determine when the angle between the folder portion and main body portion narrows to a specific angle such that the measuring means may be activated to measure the impact force upon folder portion closure. Preferably, the processing means includes an analog-digital converter to convert a DC level from the measuring means to digital data which may be compared to digital data stored in the storage means. In another aspect of the invention, an apparatus is provided for detecting closure of the folder portion of a folder-type device, measuring the force with which the folder portion is closed, comparing the measured force with predetermined levels of force, and generating an output to inform the user of the relative force with which the folder portion was closed. The apparatus includes a detector, an audio circuit, a driving unit, a strength determining unit, an output unit, and a memory. The detector determines whether the folder portion is open or closed. It is contemplated that the detector may be located in the main body portion of the device and sense the magnetism of a magnet in the folder portion in order to determine the relative proximity of the folder portion to the main body portion. Preferably, the detector includes a Hall effect device. The audio circuit receives and records the impact sound upon closing the folder portion. Preferably, the audio input circuit includes a microphone for recording the impact sound, an amplifier for amplifying the recorded impact sound and a filter, for example a low-pass filter, to convert the amplified impact sound to a DC level. The driving unit provides power to the audio circuit when closure of the folder portion is detected. It is contemplated that the driving circuit will power the audio circuit when the folder portion is at a specific angle with respect to the main body portion such that the audio circuit may record the impact sound a predetermined amount of time later when the folder portion contacts the main body portion. The strength determining unit performs functions similar to a processor. The strength determining unit determines the strength with which the folder portion was closed and generates the appropriate display. The strength determining unit determines the strength of the folder portion closure by controlling the driving unit to power the audio circuit to record the impact sound upon folder portion closure and then comparing the recorded impact sound to predetermined levels of folder portion closure impact force that are stored in the memory. Once the relative strength of the impact sound is determined, the strength determining unit retrieves the corresponding output data from the memory and transfers the output data to the output unit. Preferably, the strength determining unit includes an analog-digital converter and is adapted to control the driving unit when the detector determines that the folder portion is at a specific angle with respect to the main body portion. The output unit receives the output data from the strength determining unit and conveys to the user the force with which the folder portion was closed. It is contemplated that audio and/or visual data may be conveyed to the user. Preferably, the output unit includes a speaker and an LED or LCD. The memory contains digital data corresponding to one or more predetermined levels of folder portion closure impact force and output data corresponding to each level of impact force. Preferably the memory contains digital data corresponding to at least an acceptable closing force, a minimally acceptable closing force, and an unacceptable closing force as well as related audio and visual output data. In another aspect of the invention, a method is provided for detecting closure of the folder portion of a folder-type device, measuring the force with which the folder portion is closed, comparing the measured force with predetermined levels of force, and generating an output to inform the user of the force with which the folder portion was closed. The method utilizes the apparatus described with respect to the other aspects of the invention and includes the steps of detecting closure of the folder portion, measuring the impact force upon closure of the folder portion, determining the relative strength of the impact force, and generating an output corresponding to the measured strength of the impact force. It is contemplated that the step of detecting closure of the folder portion may include determining when the folder portion is at a specific angle with respect to the main body portion. Preferably, this step utilizes a magnet in the folder portion and a Hall effect device in the main body portion to sense the magnetism of the magnet. It is contemplated that the step of measuring the impact force may utilize an audio circuit that is powered upon detecting closure (or imminent closure) of the folder portion. Preferably, the audio circuit includes a microphone to record the impact sound, an amplifier to amplify the recorded sound, and a filter to convert the recorded impact sound to a DC level. It is contemplated that the step of determining the strength of the measured impact force may include comparing digital data corresponding to the recorded impact sound to digital data corresponding to predetermined levels of folder portion closure impact force that are stored in memory. Preferably a processor having an analog-digital converter is utilized. It is contemplated that the step of generating an output may include retrieving predetermined audio and visual digital data corresponding to the determined relative strength of the recorded impact sound from memory and transferring the digital data to an output unit adapted to provide both an audio and a visual output. Preferably, the output unit includes a speaker and an LED or LCD. Other features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. Features, elements, and aspects of the invention that are referenced by the same numerals in different figures represent the same, equivalent, or similar features, elements, or aspects in accordance with one or more embodiments. FIG. 1 illustrates one example of an apparatus for sensing the closing of the folder portion of a folder-type terminal in accordance with conventional art. FIG. 2 illustrates another example of an apparatus for sensing the closing of the folder portion of a folder-type terminal in accordance with conventional art. FIG. 3 illustrates one embodiment of an apparatus for sensing the impact strength of closing of the folder portion of a folder-type terminal in accordance with the present invention. FIG. 4 illustrates another embodiment of an apparatus for sensing the impact strength of closing of the folder portion of a folder-type terminal in accordance with the present invention. FIG. 5 is a flow chart of a method for sensing the impact strength of closing of the folder portion of a folder-type terminal in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to an apparatus and method for detecting the closure of the folder portion of a folder-type device and generating an output indicative of strength of the impact of the folder portion against the main body portion. Although the present invention is illustrated with regard to a folder-type mobile communication terminal, such as a mobile phone, it is contemplated that the present invention may be utilized with any folder-type device. Referring to FIG. 3, one embodiment of the present invention is shown. The apparatus 50 includes detecting module 102, measuring module 110, storage module 130, output module 135, and processing module 120. It is contemplated that that the majority of the apparatus is located in the main body portion (not shown) of a folder-type device. The detecting module 102 determines when the folder portion (not shown) of a folder-type device is closed. It is contemplated that the detecting module may be adapted to determine when the folder portion is at a specific angle with respect to the main body portion such that the imminent closure of the folder portion may be determined, thereby allowing the measuring means 110 to be activated before the folder portion is fully closed. The measuring module 110 measures the impact force when the folder portion contacts the main body portion. It is contemplated that the measuring module 110 may convert a recorded impact sound to a DC level that is utilized by the processing means 120. The storage module 130 contains information regarding predetermined levels of folder portion closure impact force as well as corresponding messages to be conveyed to the user via the output module 135. It is contemplated that the information is stored as digital data. It is further contemplated that information and messages corresponding to several different levels of folder portion closure impact force may be stored, for example levels corresponding to an acceptable closing force, a minimally acceptable closing force, and an unacceptable closing force. The levels may be determined based on the characteristics of the specific device for which the apparatus is used. The output module 135 is utilized to convey to the user of the device the force with which the folder portion was closed. The output module 135 conveys messages based on the information stored in the storage module 130 for each of the predetermined levels of folder portion closure impact force. By informing the user of the force with which the folder portion is closed, the user may be educated regarding the proper level of force to use to avoid damaging the device. It is further contemplated that both audio and visual messages may be conveyed. The processing module 120 controls the other modules and performs the comparison of the impact force measured by the measuring module 110 to the predetermined folder portion closure impact force information stored in the storage module 130. It is contemplated that the processing module 120 includes an analog-digital converter to convert a DC level from the measuring module 110 to digital data for comparison to digital data stored in the storage module 130. It is further contemplated that the processing module 120 may be adapted to monitor the detecting module 102 in order to determine when the angle between the folder portion and main body portion narrows to a specific angle such that the measuring module 110 may be activated to measure impact force a predetermined time later, thereby recording the impact force when the folder portion contacts the main body portion. In operation, the processing module 120 monitors the detecting module 102 to determine when the folder portion of a folder-type device is closed. Upon closure, the processing module 120 activates the measuring module 110 to measure the impact force. The processing module 120 then retrieves the measured impact force and compares it to predetermined levels of folder portion closure impact force stored in the storage module 130 to determine the relative strength of the impact. The processing module 120 then retrieves the corresponding output information from the storage means 130 and transfers the information to the output module 135. A preferred embodiment of the apparatus 100 is illustrated in FIG. 4. The detecting module 102 is preferably a Hall effect device and the folder portion (not shown) has a magnet 101 therein. The measuring module 110 is an audio circuit. The storage module 130 is a memory. The output module 135 includes both a display and audio output unit. The processing module 120 is preferably a Mobile Station Modem (MSM). The audio circuit 110 includes a microphone 111, an amplifier 112, and a filter 113, preferably a Low Pass Filter (LPF). The microphone records the impact sound generated when the folder portion is closed. The amplifier 112 amplifies the recorded impact sound according to a predetermined gain. The filter 113 converts the amplified impact sound to a DC level. The MSM 120 includes an interrupt processor 121, an audio circuit driving unit 122, an analog-digital converter (ADC) 123, a strength determining unit 124, a sound/display unit 125, a visual display generator 126, and a sound generator 127. The interrupt processor 121 generates an interrupt when the Hall effect device 102 detects closure of the folder portion. The audio circuit driving unit 122 activates the audio circuit 110 under the control of the interrupt processor 121. Preferably, the interrupt is generated prior to complete closure of the folder portion such that the audio circuit is activated in time to record the impact sound when the folder portion contacts the main body portion. The ADC converts a DC level indicative of the impact sound from the audio circuit 110 to a digital signal. The strength determining unit 124 compares the output of the ADC to digital data corresponding to predetermined levels of folder portion closure impact force retrieved from the memory 130 in order to determine the relative strength of the recorded impact sound. The sound/display unit 125 retrieves audio and visual data corresponding to the determined relative strength of the recorded impact sound from the memory 130. The visual display generator 126 transfers the visual data to a display 140, preferably an LED or LCD. The sound generator 127 transfers the audio data to an audio output unit 150. In operation, the audio circuit 110 is activated upon detection of closure of the folder portion at a specific angle between the folder portion and main body portion. Once activated, the audio circuit 110 records the impact sound generated a predetermined time later when the folder portion contacts the main body portion. The relative strength of the recorded impact sound with respect to predetermined levels of folder portion closure impact force is determined by the MSM 120 and various sounds and visual displays are created according to the determined relative strength of impact. For example, the strength of the impact sound recorded when the folder portion is closed may be compared to, for example, four predetermined levels stored in the memory 130; the first and second levels being acceptable levels of closing force, the third level a marginally-acceptable level of closing force, and the fourth level an unacceptable level of closing force. Corresponding sounds and visual data may be set according to the relative impact strength level. If the determined strength of impact upon closing the folder portion is at or below the first level, a sound such as ‘You are too weak! Thank you!’ may be generated. If the determined strength of impact in closing the folder portion is between the first and second levels, a sound such as ‘Wow! You are too careful!’ may be generated. If the determined strength of impact in closing the folder portion is between the second and third levels, a sound such as ‘Thank you for closing gently!’ may be generated. If the determined strength of impact in closing the folder portion is between the third and the fourth level, a sound such as ‘Please close gently!’ may be generated. If the determined strength of impact in closing the folder portion is above the fourth level, a sound such as ‘Ouch! It hurts. Please close gently!’ may be generated. In addition, each sound may also have an associated visual display in the form of a character or amusing image. Referring to FIG. 5, a flow chart of a method of using the apparatus of the present invention is illustrated. The method includes the steps of detecting closure of the folder portion (S11), measuring the impact force (S13), determining the relative strength of the measured impact force (S15), determining output data according to impact strength (S17), and generating an output (S19). In use, when the folder portion of a folder-type terminal is opened, it moves about the main body portion. When the folder portion is completely closed, the folder portion and the main body portion are at the angle of 0°. In step S11, a detector 102 such as a Hall effect device is utilized to determine when the folder portion is closed. For example, the detector may determine when the angle between the folder portion and the main body portion narrows to a specific angle, thereby indicating imminent closure the folder portion. When the detector 102 senses closure of the folder portion, an output level is generated to indicate detection of folder portion closing. A processor 120 such as an MSM receives the output level and generates an interrupt. In step S13 an interrupt processor 121 controls a driving unit 122. The driving unit 122 activates a measuring module 110 such as an audio circuit, for example, by applying power to a microphone 111, setting a predetermined amplification gain for an amplifier 112, and applying power to initialize an ADC 123. After a predetermined time to allow for the angle between the folder portion and main body portion to decrease to 0°, the microphone 111 records the impact sound. The recorded impact sound is amplified by the amplifier 112 and filtered by a filter 113, with the resulting DC level converted by the ADC 123 to a digital signal. In step S15, a strength determining unit 124 in the MSM 120 determines the relative strength of the measured impact force. The strength determining unit 124 retrieves the digital data for predetermined levels of folder portion closure impact force from a memory 130 and compares that digital data to the digital signal corresponding, for example, to the recorded impact sound to determine the appropriate predetermined level to which the measured impact force corresponds. In step S17, a sound/display unit 125 in the MSM 120 is utilized to determine the output data corresponding to the measured impact force. The sound/display unit 125 may retrieve digital audio and/or visual output data corresponding to the measured impact force from the memory 130. In step S19, the retrieved audio and/or visual output data are utilized to generate the appropriate output. Audio data is transferred to an audio output unit 150 through a sound generator 127 in the MSM 120 and visual data is transferred to the display 140 through a visual display generator 126 in the MSM. The audio output unit 150 outputs sound while the display unit 140 displays visual data. It is contemplated that the sound/display unit 125 may transfer only audio data or only visual data depending on a state set by the user. The apparatus and method of the present invention have several advantages. Because the imminent closing of the folder portion of a folder-type device may be determined by the specific angle between the folder portion and main body portion, the impact force when the folder portion contacts the main body portion may be measured. Determining the strength of the impact upon closure of the folder portion rather than just the open/closed configuration the folder portion allows the user to be provided with important information that may decrease wear on the folder-type device and lessen the tendency of the folder portion to break The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structure described herein as performing the recited function and not only structural equivalents but also equivalent structures. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a folder-type terminal and, more particularly, to an apparatus and method for determining the strength of impact when the folder portion of a folder-type terminal is closed and generating a display corresponding to the determined strength of impact. 2. Description of the Related Art As the use of mobile communications terminals has increased, the use of folder-type terminals has increased. Although such terminals have an advantage in that they are more compact and less bulky to store and carry, they also have disadvantages. One of the disadvantages is that users have experienced an increased occurrence of breakage in the folder portion of these terminals. One of the possible reasons for this breakage is that users tend to close the terminals with sufficient force to weaken and damage the apparatus attaching the folder portion to the main body portion of the terminal. Although it is known in the art to sense the opening and closing of a folder-type terminal, sensing the impact upon closing such a terminal would allow the user to determine if he or she is closing the terminal in a manner that may lead to damage to the folder portion. FIG. 1 illustrates one example of a conventional apparatus for sensing the closure of the folder portion of a folder-type terminal. The terminal 1 includes a folder portion 10 with a protrusion 11 at a certain position along the folder portion and a main body portion 20 having a contact switch 21 at a position where the protrusion contacts the main body portion. As illustrated in FIG. 1 , the terminal 1 detects opening and closing of the folder portion 10 by a mechanical contact between the protrusion 11 and the contact switch 21 . When the folder portion 10 is closed, the protrusion 11 of the folder 10 depresses the contact switch 21 of the main body portion 20 to cut off (or supply) a current flowing to the contact switch 21 . Accordingly, the terminal 1 detects opening or closing of the folder 10 based on whether or not current flows at the contact switch 21 . Although the terminal 1 illustrated in FIG. 1 can determine whether the folder portion 10 is open or closed, it can detect only the fully open or fully closed configuration, not the configuration where the folder portion 10 is in the process of closing. Furthermore, the terminal 1 illustrated in FIG. 1 cannot determine the force with which the folder portion 10 is closed. FIG. 2 illustrates another example of a conventional apparatus for sensing the closure of the folder portion of a folder-type terminal. The terminal 25 includes a folder portion 30 having a magnet 31 at a certain position along the folder portion and a main body portion 40 having a Hall effect switch 41 for sensing the magnetic field of the magnet of the folder portion. As illustrated in FIG. 2 , the terminal 25 detects opening and closing of the folder portion 30 by using a Hall effect switching method. As the folder portion 30 is closed, the magnet 31 nears the Hall effect switch 41 of the main body portion 40 . The Hall effect switch 41 senses the magnetic field of the magnet 31 and changes an output accordingly. A Mobile Station Modem (MSM) (not shown) of the main body portion 40 detects the change in the output of the Hall effect switch 41 and determines whether the folder portion 30 is open or closed. The terminal 25 illustrated in FIG. 2 may be able to determine the “imminent closure” configuration in addition to the fully closed and fully open configuration. However. The terminal 25 illustrated in FIG. 2 still cannot detect the force with which the folder portion 30 is closed. Therefore, there is a need for an apparatus that can determine not only the closing or opening of the folder portion of a folder-type terminal, but also the force with which the folder portion is closed. The present invention addresses this and other needs. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to an apparatus and method for detecting the closure of the folder portion of a folder-type device and generating a display indicative of the strength of the impact of the folder portion against the main body portion. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention is embodied an apparatus for detecting the closure of the folder portion of a folder-type device. Specifically, an apparatus is provided that detects closure of the folder portion of a folder-type device, measures the impact of the closure, and generates a display to the user that is indicative of the strength of the impact. In one aspect of the invention, means are provided for detecting closure of the folder portion of a folder-type device, measuring the force with which the folder portion is closed, comparing the measured force with predetermined levels of force, and generating an output to inform the user of the force with which the folder portion was closed. The predetermined levels of force for comparison to the measured force as well as displays corresponding to each predetermined level of force are provided in a storage means. A processing means controls a detecting means, measuring means, output means, and storage means as well as performing the comparison of the measured impact to the predetermined levels of impact. The detecting means determines whether the folder portion is open or closed. It is contemplated that the detecting means may be adapted to determine when the folder portion is at a specific angle with respect to the main body portion of the device in order to activate the measuring means in time to measure the impact of the closure of the folder portion. Preferably, the detecting means includes a magnet in the folder portion and a sensor in the main body portion such that the magnetism of the magnet is sensed to determine when the folder portion is in proximity to the main body portion. The measuring means is adapted to measure the impact force when the folder portion contacts the main body portion. Preferably the measuring means includes a microphone for recording the impact sound, an amplifier for amplifying the recorded sound, and a filter, for example a low-pass filter, for converting the amplified sound to a DC level. The output means conveys to the user of the device the force with which the folder portion was closed in order to educate the user in the proper level of force with which to close the folder portion without damaging the device. It is contemplated that both an audible and visual message may be conveyed to the user. The storage means is adapted to store information regarding predetermined levels of folder portion closure impact force as well as corresponding messages to be conveyed to the user via the output means. It is contemplated that digital data corresponding to several different levels of folder portion closure impact force may be stored, for example levels corresponding to an acceptable closing force, a minimally acceptable closing force, and an unacceptable closing force. It is further contemplated that the predetermined levels of folder portion closure impact force may be determined based on the characteristics of the specific device for which the apparatus is used. The processing means controls the other means and performs the comparison of the impact force measured by the measuring means to the predetermined folder portion closure impact force levels stored on the storage means. It is contemplated that the processing means may be adapted to monitor the detecting means in order to determine when the angle between the folder portion and main body portion narrows to a specific angle such that the measuring means may be activated to measure the impact force upon folder portion closure. Preferably, the processing means includes an analog-digital converter to convert a DC level from the measuring means to digital data which may be compared to digital data stored in the storage means. In another aspect of the invention, an apparatus is provided for detecting closure of the folder portion of a folder-type device, measuring the force with which the folder portion is closed, comparing the measured force with predetermined levels of force, and generating an output to inform the user of the relative force with which the folder portion was closed. The apparatus includes a detector, an audio circuit, a driving unit, a strength determining unit, an output unit, and a memory. The detector determines whether the folder portion is open or closed. It is contemplated that the detector may be located in the main body portion of the device and sense the magnetism of a magnet in the folder portion in order to determine the relative proximity of the folder portion to the main body portion. Preferably, the detector includes a Hall effect device. The audio circuit receives and records the impact sound upon closing the folder portion. Preferably, the audio input circuit includes a microphone for recording the impact sound, an amplifier for amplifying the recorded impact sound and a filter, for example a low-pass filter, to convert the amplified impact sound to a DC level. The driving unit provides power to the audio circuit when closure of the folder portion is detected. It is contemplated that the driving circuit will power the audio circuit when the folder portion is at a specific angle with respect to the main body portion such that the audio circuit may record the impact sound a predetermined amount of time later when the folder portion contacts the main body portion. The strength determining unit performs functions similar to a processor. The strength determining unit determines the strength with which the folder portion was closed and generates the appropriate display. The strength determining unit determines the strength of the folder portion closure by controlling the driving unit to power the audio circuit to record the impact sound upon folder portion closure and then comparing the recorded impact sound to predetermined levels of folder portion closure impact force that are stored in the memory. Once the relative strength of the impact sound is determined, the strength determining unit retrieves the corresponding output data from the memory and transfers the output data to the output unit. Preferably, the strength determining unit includes an analog-digital converter and is adapted to control the driving unit when the detector determines that the folder portion is at a specific angle with respect to the main body portion. The output unit receives the output data from the strength determining unit and conveys to the user the force with which the folder portion was closed. It is contemplated that audio and/or visual data may be conveyed to the user. Preferably, the output unit includes a speaker and an LED or LCD. The memory contains digital data corresponding to one or more predetermined levels of folder portion closure impact force and output data corresponding to each level of impact force. Preferably the memory contains digital data corresponding to at least an acceptable closing force, a minimally acceptable closing force, and an unacceptable closing force as well as related audio and visual output data. In another aspect of the invention, a method is provided for detecting closure of the folder portion of a folder-type device, measuring the force with which the folder portion is closed, comparing the measured force with predetermined levels of force, and generating an output to inform the user of the force with which the folder portion was closed. The method utilizes the apparatus described with respect to the other aspects of the invention and includes the steps of detecting closure of the folder portion, measuring the impact force upon closure of the folder portion, determining the relative strength of the impact force, and generating an output corresponding to the measured strength of the impact force. It is contemplated that the step of detecting closure of the folder portion may include determining when the folder portion is at a specific angle with respect to the main body portion. Preferably, this step utilizes a magnet in the folder portion and a Hall effect device in the main body portion to sense the magnetism of the magnet. It is contemplated that the step of measuring the impact force may utilize an audio circuit that is powered upon detecting closure (or imminent closure) of the folder portion. Preferably, the audio circuit includes a microphone to record the impact sound, an amplifier to amplify the recorded sound, and a filter to convert the recorded impact sound to a DC level. It is contemplated that the step of determining the strength of the measured impact force may include comparing digital data corresponding to the recorded impact sound to digital data corresponding to predetermined levels of folder portion closure impact force that are stored in memory. Preferably a processor having an analog-digital converter is utilized. It is contemplated that the step of generating an output may include retrieving predetermined audio and visual digital data corresponding to the determined relative strength of the recorded impact sound from memory and transferring the digital data to an output unit adapted to provide both an audio and a visual output. Preferably, the output unit includes a speaker and an LED or LCD. Other features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. | 20040709 | 20060919 | 20050224 | 73782.0 | 0 | NGHIEM, MICHAEL P | APPARATUS AND METHOD FOR DETERMINING STRENGTH OF IMPACT WHEN CLOSING A FOLDER-TYPE TERMINAL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,888,194 | ACCEPTED | Tool for disconnecting a fuel line from a fitting | A tool for removal of a fuel line from a vehicle fuel module by engagement of and displacement of a locking member, said tool including first and second arms with semi-cylindrical sections at each end that may be used in combination to engage the locking member. | 1. A tool for disconnecting a fuel line having a longitudinal axis from a fitting, said fuel line of the type including a biased, locking ring for retaining the fuel line engaged with the fitting, said fuel line being disengaged from the fitting by longitudinal axis movement from the fitting, said tool comprising, in combination: a first arm member, said first arm member including an elongate body member with a first end and a second end and having a generally elongate axis from the first and to the second end; a first semi-cylindrical section at the first end having an axis of said first section generally transverse to the elongate axis, and a second semi-cylindrical section at the second end having an axis of said second section generally transverse to the elongate axis; and a second arm member including an elongate body member with a first end and a second end and having a generally elongate axis from the second arm member first end to the second arm member second end; a first semi-cylindrical section at the first end of the second member the same size as the first semi-cylindrical section of the first member and also having a cylinder axis generally transverse to the second arm member elongate axis, and a second semi-cylindrical section at the second end of the second arm member and also having a cylinder axis generally transverse to the second arm member elongate axis, said first elongate member first cylindrical section and said second elongate member first cylindrical section generally identical in size; said first elongate member second cylindrical section and said second elongate member second cylindrical section generally identical in size and having a distinct size from the first cylindrical sections, whereby said first cylindrical sections or said second cylindrical sections may be positioned against a locking ring to effect longitudinal axis movement of the ring and thereby to disengage the ring from the fitting. 2. The tool of claim 1 wherein the axes of the cylindrical members are parallel. 3. The tool of claim 1 wherein the elongate arm axes are straight. 4. The tool of claim 1 wherein the fist and second arms are substantially mirror images of each other. 5. The tool of claim 1 wherein the axes of the first cylindrical sections are coincident when the arms are positioned together for engagement with a locking ring. 6. The tool of claim 1 wherein the axes of the second cylindrical sections are coincident when the arms are positioned for engagement with a locking ring. | BACKGROUND OF THE INVENTION In a principal aspect, the present invention relates to a tool useful for disconnection of both the inlet and outlet fuel supply lines to the fuel tank of a vehicle. The disconnect tool may be used in other environments, however, to disconnect fluid transport lines of the type which utilize a biased locking cylinder lock for engagement with a fitting compatible with the tube or line. Various modern vehicles utilize fluid transfer lines which incorporate a cylindrical fitting at the end of the line capable of engaging and locking into a fitting. For example, the fuel lines of General Motors vehicles utilize a fuel module which includes an inlet line and an outlet line. Each line includes a cylindrical locking member which is biased in a longitudinal direction so as to lock against a fitting. To remove the fuel line from a fuel module fitting, it is necessary to push the cylindrical locking member against the biasing force. Once positioned in a release position, the cylinder lock no longer engages the fitting and the fuel line may be removed from the fitting. Various other motor vehicles utilize such fitting constructions. Heretofore, there have been made available certain tools for the removal of such lines from fittings. For example, Snap-On Tools provides a fuel line disconnect tool set, Model YA9457 for such use. The described tool is in the form of a pliers which include elements at the distal or outer ends of the arms of the pliers. These elements may be positioned to engage the locking members to effect their disengagement from a fuel module. Nonetheless, there has remained the need to provide a simple and inexpensive tool to disconnect fuel lines from fuel modules, particularly those associated with General Motors vehicles, but also for other vehicles and other instances where such lines are to be disconnected from a fitting. Such a tool, desirably, must be useable in a number of environments where access to the connection assembly is limited. These among other needs led to the development of the present tool. SUMMARY OF THE INVENTION Briefly, the present invention comprises a tool for removal of, or disconnection of a fuel line from a fitting. The fuel line is of the type which includes a biased generally cylindrical locking ring on the end of the fuel line for engaging and retaining the fuel line with a fitting. In order to disengage the fuel line from the fitting, the cylindrical locking member associated with the fuel line must be biased or moved against the biasing force to release the fuel line from engagement with the fitting. The tool of the present invention accomplishes these objectives by providing a first arm member which includes an elongate body section with semi-cylindrical end sections projecting from opposite ends of the body member. A separate, second arm member, which in a preferred embodiment, is substantially a mirror image of the first arm member. The semi-cylindrical end sections of each of the arm members are designed to be separately engageable with the cylindrical locking ring of a fuel line. In operation, a first one of the semi-cylindrical sections is engaged with the end of the fuel line to move or push the locking ring in a desired manner. The second arm member is then appropriately positioned in combination with the first arm member so that the appropriate cylindrical sections of the first and second arm members are engaged with the locking ring of the fuel line. In this manner, each of the separate arm members may be positioned independently in a manner which in combination will effect release of the fuel line. As a result, the tool is very useful, particularly in highly restricted areas. That is, because the tool is comprised of two separate elements; namely, a first arm member and a second arm member which are independent of one another, the elements may be independently positioned to engage a fuel line locking ring and release that ring. Adjustment of the arm members independently of each other and positioning of the arm members independently of each other, but in the final analysis assembling them in combination, provides a tool which is highly effective for removal of fuel lines, particularly in restricted areas. Thus, it is an object of the invention to provide an improved tool for disconnecting a fuel line from a fitting. It is a further object of the invention to provide a tool for disconnecting lines from fittings wherein the tool is comprised of independent and separate first and second arm members which work in combination to effect such removal. A further object of the invention is to provide a tool for disconnecting a fuel line from a fitting which is economical, easy to use, rugged, and inexpensive. These and other objects, advantages and features of the invention will be set forth in the detailed description which follows. BRIEF DESCRIPTION OF THE DRAWING In the detailed description which follows reference will be made to the drawing comprised of the following figures: FIG. 1 is a side elevation of a first arm member or right hand arm of the tool; FIG. 2 is a top plan view of the arm of FIG. 1; FIG. 3 is a bottom plan view of the arm of FIG. 1; FIG. 4 is a right hand end view of the tool of FIG. 1; FIG. 5 is a left hand end view of the tool of FIG. 1; FIG. 6 is a plan view of the second arm member or left hand arm of the tool of the invention; FIG. 7 is a bottom plan view of the arm of FIG. 6; FIG. 8 is a top plan view of the arm of FIG. 6; FIG. 9 is a right hand end view of the arm of FIG. 6; FIG. 10 is a left hand end view of the arm of FIG. 6; FIG. 11 is an isometric view illustrating the manner of positioning first arm member on a fuel line attached to a fuel module fitting; FIG. 12 illustrates the movement and further positioning of the arm member depicted in FIG. 11 in an isometric view; FIG. 13 is an isometric view illustrating the positioning of the second arm member in combination with a first arm member on a fuel line attached to a fuel module fitting; and FIG. 14 is an isometric view of the tool of the invention illustrating the first arm member and second arm member joined back to back prior to positioning on a fuel line for removal thereof. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the tool of the invention is comprised of two separate or independent parts. One part comprises a first arm member 20 as illustrated in FIGS. 1-5. The second part comprises a second arm member 50 as illustrated in FIGS. 6-10. The first arm member 20 and the second arm member 50 are generally mirror images of each other. Thus, many of the aspects of the description of the first arm member 20 apply to the construction of the second arm member 50. Further, each arm member 20, 50 may be made from a molded plastic material such as acetal. However, the material utilized to manufacture the arm members 20 and 50 is not a limiting feature of the invention. Referring therefore to FIGS. 1-5, the first arm member 20 which is also conveniently called a right arm 20, includes an elongate body member 22. The elongate body member 22 includes a first end 24 and an opposite or second end 26. A generally longitudinal straight line axis 28 extends between the ends 24 and 26. Projecting transversely to the axis 28 is a first, semi-cylindrical section 30 having an axis 32 generally transverse to the axis 28. Similarly, projecting from the second end 26 is a semi-cylindrical section 34 having an axis 36 also transverse to the longitudinal axis 28. In the preferred embodiment, the axes 32, 36 are parallel and the body member 22 is a straight line body member extending between the ends 24 and 26 and thus the axis 28 is a straight line axis. However, the axis 28 may be curved, angled, or otherwise configured. Most importantly, the body member 22 includes the first and second ends 24 and 26 having the transversely extending semi-cylindrical sections 30 and 34. Dimensionally, the spacing of the transverse axes 32 and 36 is in the range of 2 inches. The longitudinal extent of the semi-cylindrical members 30 and 34 is in the range of approximately ½ inch. Such dimensional characteristics enable use of the tool in highly restricted areas and facilitate manipulation by a service worker or mechanic. The body member includes a series of projecting tabs 39, 40 and 41 which are provided merely for joinder of the first body member 20 to the second body member 50 for purposes of storage or display. In other words, the tabs 39, 40 and 41 do not become functionally involved in the operation of removal of a fuel line from a fitting. The semi-cylindrical sections 30 and 34 are preferably formed so as to define a half section of a cylinder. However, the semi-cylindrical sections 30, 34 may be formed to be less than the half section of a cylinder. Thus, the invention is not to be limited to strictly semi-circular cylindrical sections 30 and 34. Lesser sections may be considered to be within the scope of the language “semi-cylindrical”. The radius of each of the semi-cylindrical sections 30 and 34 is different. In other words, the semi-cylindrical section 30 has a lesser diameter or radius than the semi-cylindrical section 34. The radii or diameters are chosen to be compatible with the locking rings associated with fuel lines and other such lines. FIGS. 6-10 disclose the second arm member 50 which is compatible with and substantially a mirror image of the first arm member 20. The second arm member 50 is also referred to as the left hand, or left arm member. Second arm member 50 thus includes an elongate body member 52 having a longitudinal axis 54. It further includes a first end 56 and the second end 58 with a semi-cylindrical section 60 associated with the first end 56 and a distinctly sized, semi-cylindrical section 62 associated with the second end 58. The semi-cylindrical section 60 has a radius or diameter substantially equal to the radius or diameter of the semi-cylindrical section 30 associated with the first arm 20. Likewise, the semi-cylindrical section 62 has a radius or diameter substantially equal to that of the semi-cylindrical section 34 associated with the first arm member 20. The semi-cylindrical section 60 includes an axis 61. The semi-cylindrical section 62 includes an axis of rotation 63. The axis 61 and the axis 63 are substantially parallel as are the axes 32 and 36 associated with the first arm member 20. In operation or use, all of the axes associated with the semi-cylindrical sections; namely, axes 61, 63, 32 and 36 are parallel to one another. Further, when the arm members 20 and 50 are in their utilitarian position, the semi-cylindrical sections 61, 63, 30 and 34 project axially in the same direction and for approximately the same distance from the body members 20 and 50. FIG. 14 illustrates in an isometric view the arm members 20 and 50 which comprise the tool. FIGS. 11-13 illustrate the manner of use of the tool. Referring therefore to FIGS. 11-13 there is illustrated a fuel tank module 70 associated with a vehicle. There is also illustrated a fuel line 72; namely, a supply line and a return line 74. Each of the fuel lines 72 and 74 connect with the respective fittings 76 and 78 associated with the module 70. Further, each of the fuel lines 72 and 74 include a ring element 80 and 82 which serves to retain the end of the fuel line 72 and 74 engaged with the appropriate fitting 76 and 78. In use, a first arm 20 is positioned so that the appropriate end thereof; namely, the larger end in FIG. 11, or in other words, the larger semi-cylindrical section 34 is positioned to engage the locking ring associated with the large fuel supply line 72. The arm 20 is then rotated so as to enable additional access for second arm 50. Thus, the arm 20 is rotated approximately 90° to a second position as illustrated in FIG. 12. Subsequently, the second arm 50 is positioned in opposition to the first arm 20 as illustrated in FIG. 13. When so positioned, the arms 20 and 50 may be manually manipulated so as to be pulled or pushed in the direction of the arrow in FIG. 13 to thereby release the locking ring member associated with the fuel line 72 and thereby disconnect the fuel line 72 from the fuel module 70. A similar operation may be performed to remove the second or smaller fuel line 74. Because the arms 20 and 50 are independent of each other, they may be independently manipulated and positioned so as to effect removal of the fuel line 72 from the fuel module 70. Further, because the opposite ends of each of the arms 20 and 50 include uniquely sized semi-cylindrical sections, the tool may be utilized with various sizes of fuel lines having variously sized fittings associated therewith. FIG. 14 illustrates the manner in which the first and second arm 20 and 50 may be connected one to the other by means of the interlocking tabs 39, 40 and 41. A preferred embodiment has been described. Variations may be effected without departing from the spirit and scope of the invention. For example, the size and orientation of the various cylindrical sections may be altered. The extent of the formation of the cylindrical sections may be adjusted. The axial configuration of the semi-cylindrical sections may be altered. The invention is therefore limited only by the following claims and equivalents thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>In a principal aspect, the present invention relates to a tool useful for disconnection of both the inlet and outlet fuel supply lines to the fuel tank of a vehicle. The disconnect tool may be used in other environments, however, to disconnect fluid transport lines of the type which utilize a biased locking cylinder lock for engagement with a fitting compatible with the tube or line. Various modern vehicles utilize fluid transfer lines which incorporate a cylindrical fitting at the end of the line capable of engaging and locking into a fitting. For example, the fuel lines of General Motors vehicles utilize a fuel module which includes an inlet line and an outlet line. Each line includes a cylindrical locking member which is biased in a longitudinal direction so as to lock against a fitting. To remove the fuel line from a fuel module fitting, it is necessary to push the cylindrical locking member against the biasing force. Once positioned in a release position, the cylinder lock no longer engages the fitting and the fuel line may be removed from the fitting. Various other motor vehicles utilize such fitting constructions. Heretofore, there have been made available certain tools for the removal of such lines from fittings. For example, Snap-On Tools provides a fuel line disconnect tool set, Model YA9457 for such use. The described tool is in the form of a pliers which include elements at the distal or outer ends of the arms of the pliers. These elements may be positioned to engage the locking members to effect their disengagement from a fuel module. Nonetheless, there has remained the need to provide a simple and inexpensive tool to disconnect fuel lines from fuel modules, particularly those associated with General Motors vehicles, but also for other vehicles and other instances where such lines are to be disconnected from a fitting. Such a tool, desirably, must be useable in a number of environments where access to the connection assembly is limited. These among other needs led to the development of the present tool. | <SOH> SUMMARY OF THE INVENTION <EOH>Briefly, the present invention comprises a tool for removal of, or disconnection of a fuel line from a fitting. The fuel line is of the type which includes a biased generally cylindrical locking ring on the end of the fuel line for engaging and retaining the fuel line with a fitting. In order to disengage the fuel line from the fitting, the cylindrical locking member associated with the fuel line must be biased or moved against the biasing force to release the fuel line from engagement with the fitting. The tool of the present invention accomplishes these objectives by providing a first arm member which includes an elongate body section with semi-cylindrical end sections projecting from opposite ends of the body member. A separate, second arm member, which in a preferred embodiment, is substantially a mirror image of the first arm member. The semi-cylindrical end sections of each of the arm members are designed to be separately engageable with the cylindrical locking ring of a fuel line. In operation, a first one of the semi-cylindrical sections is engaged with the end of the fuel line to move or push the locking ring in a desired manner. The second arm member is then appropriately positioned in combination with the first arm member so that the appropriate cylindrical sections of the first and second arm members are engaged with the locking ring of the fuel line. In this manner, each of the separate arm members may be positioned independently in a manner which in combination will effect release of the fuel line. As a result, the tool is very useful, particularly in highly restricted areas. That is, because the tool is comprised of two separate elements; namely, a first arm member and a second arm member which are independent of one another, the elements may be independently positioned to engage a fuel line locking ring and release that ring. Adjustment of the arm members independently of each other and positioning of the arm members independently of each other, but in the final analysis assembling them in combination, provides a tool which is highly effective for removal of fuel lines, particularly in restricted areas. Thus, it is an object of the invention to provide an improved tool for disconnecting a fuel line from a fitting. It is a further object of the invention to provide a tool for disconnecting lines from fittings wherein the tool is comprised of independent and separate first and second arm members which work in combination to effect such removal. A further object of the invention is to provide a tool for disconnecting a fuel line from a fitting which is economical, easy to use, rugged, and inexpensive. These and other objects, advantages and features of the invention will be set forth in the detailed description which follows. | 20040709 | 20061031 | 20060112 | 98072.0 | B23P1904 | 1 | WATSON, ROBERT C | TOOL FOR DISCONNECTING A FUEL LINE FROM A FITTING | SMALL | 0 | ACCEPTED | B23P | 2,004 |
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10,888,312 | ACCEPTED | Rotary pulser for transmitting information to the surface from a drill string down hole in a well | A rotary pulser for transmitting information to the surface from down hole in a well by generating pressure pulses encoded to contain information. The pressure pulses travel to the surface where they are decoded so as to decipher the information. The pulser includes housing containing a stator forming passages through which drilling fluid flows on its way to the drill bit, a rotor, and a replaceable wear sleeve enclosing the rotor. The rotor has blades that are capable of imparting a varying obstruction to the flow of drilling fluid through the stator passages depending on the circumferential orientation of the rotor, so that rotation of the rotor by a motor generates the encoded pressure pulses. The rotor is located downstream of the stator and the rotor blades are shaped so that when the motor is not in operation, a hydrodynamic opening torque is imparted to the rotor that tends to rotate the rotor blades away from the circumferential orientation that results in the maximum obstruction and toward the circumferential orientation that results in the minimum obstruction. A torsion spring provides a mechanical force that also tends to rotate the rotor into the orientation that provides the minimum flow obstruction. | 1. A rotary pulser for transmitting information from a portion of a drill string operating at a down hole location in a well bore, said drill string having a passage through which a drilling fluid flows, comprising: a) a housing adapted to be mounted in said drill string; b) a stator supported in said housing and having at least one approximately axially extending passage formed therein through which at least a portion of said drilling fluid flows; c) a rotor supported in said housing adjacent said stator and downstream therefrom, said rotor having at least one blade extending radially outward so as to define a radial height thereof, said rotor being rotatable into at least first and second circumferential orientations, said blade imparting a varying degree of obstruction to said flow of drilling fluid flowing through said stator passage depending on the circumferential orientation of said rotor, said first rotor circumferential orientation providing a greater obstruction to said flow of drilling fluid than that of said second rotor circumferential orientation, whereby rotation of said rotor generates a series of pulses encoded with said information to be transmitted; d) a motor coupled to said rotor for imparting rotation to said rotor, whereby operation of said motor generates said series of encoded pulses; and e) means for imparting a torque to said rotor when said motor is not operating to transmit said information that urges said rotor to rotate away from said first circumferential orientation toward said second circumferential orientation so as to reduce the obstruction imparted by said blade to said flow of drilling fluid when said motor is not operating. 2. The rotary pulser according to claim 1, wherein said torque imparting means comprises a spring mounted within said housing. 3. The rotary pulser according to claim 2, wherein said spring comprises a torsion spring having a first end coupled to said housing and a second end coupled to said rotor. 4. The rotary pulser according to claim 3, wherein said torsion spring is mounted so as to impose a torque on said shaft when said rotor is rotated into said first circumferential orientation that drives said rotor toward said second circumferential orientation. 5. The rotary pulser according to claim 1, wherein said rotor blade has upstream and downstream surfaces defining a thickness of said rotor blade therebetween, and wherein said torque imparting means comprises said rotor blade downstream surface being inwardly tapered as it extends in the downstream direction. 6. The rotary pulser according to claim 1, wherein said torque imparting means comprises at least a major portion of said radial height said rotor blade having a shape in transverse cross-section formed by superimposing a thickened central rib onto a thinner plate-like portion. 7. The rotary pulser according to claim 6, wherein said plate-like portion forms first and second lateral sides of said blade and a substantially flat surface therebetween. 8. The rotary pulser according to claim 7, wherein said plate-like portion forms first and second lateral sides of said blade, and wherein said thickness of said plate-like portion proximate said first and second lateral sides is no more than approximately ¼ inch (6 mm) over at least a major portion of said radial height of said blade. 9. The rotary pulser according to claim 6, wherein the thickness of said central rib is tapered so as to be thinner as said blade extends radially outward. 10. The rotary pulser according to claim 1, wherein said rotor blade has upstream and downstream surfaces defining a thickness therebetween, said rotor blade downstream surface extending in both the radial and circumferential directions, and wherein said torque imparting means comprises said rotor blade downstream surface being profiled over at least a major portion of said radial height of said blade so that in transverse cross section said thickness of said rotor blade increases as said surface extends downstream. 11. The rotary pulser according to claim 10, wherein said rotor blade has first and second lateral sides defining the circumferential width of said rotor blade therebetween, and wherein said downstream surface of said rotor blade is profiled over at least a major portion of said radial height of said blade so that in transverse cross section said thickness of said rotor blade is at a minimum proximate said first and second lateral sides. 12. The rotary pulser according to claim 10, wherein. said rotor blade has first and second lateral sides, and wherein said thickness of said blade proximate said first and second lateral sides is no more than approximately ¼ inch (6 mm) over at least a major portion of said radial height of said blade. 13. The rotary pulser according to claim 12, wherein. said rotor blade has a radially outward tip, and wherein said thickness of said blade proximate said tip is no more than approximately ¼ inch (6 mm). 14. The rotary pulser according to claim 10, wherein said downstream surface of said rotor blade is profiled over at least a major portion of said radial height of said blade so that in transverse cross section said thickness of said rotor blade is at a maximum approximately midway between said first and second lateral sides. 15. The rotary pulser according to claim 10, wherein said rotor blade has first and second lateral sides defining the circumferential width of said rotor blade therebetween, wherein. said rotor blade downstream surface is profiled over at least a major portion of said radial height of said blade so that in transverse cross-section said thickness of said rotor blade generally decreases as said surface extends circumferentially toward said lateral sides in the both the clockwise and counterclockwise directions over at least a portion of the circumferential width of said blade. 16. The rotary pulser according to claim 10, wherein said rotor blade downstream surface is profiled so that said thickness of said rotor blade generally decreases as said surface extends radially outward over at least a major portion of said radial height of said blade. 17. The rotary pulser according to claim 16, wherein said rotor blade downstream surface is profiled so that said decrease in thickness is obtained by displacing said downstream surface in the upstream direction as said blade extends radially outward. 18. The rotary pulser according to claim 10, wherein said upstream surface of said rotor blade forms a substantially planar surface. 19. The rotary pulser according to claim 10, wherein said stator passage and said rotor blade each have a width in the circumferential direction, said circumferential width of said rotor blade being greater than said width of said stator passage. 20. The rotary pulser according to claim 10, wherein said stator passage comprises means for swirling said drilling fluid in a circumferential direction. 21. The rotary pulser according to claim 1, wherein said motor rotates said rotor in an oscillatory fashion in both clockwise and counterclockwise directions to generate said pulses. 22. The rotary pulser according to claim 1, wherein said motor rotates said rotor in a single direction to generate said pulses. 23. The rotary pulser according to claim 1, wherein said stator comprises at least one vane adjacent said passage, and wherein said rotor blade is aligned with said vane when said rotor is in said second circumferential orientation. 24. The rotary pulser according to claim 1, wherein said rotor blade is aligned with said passage when said rotor is in said first circumferential orientation. 25. The rotary pulser according to claim 24, wherein said rotor blade has first and second lateral sides, and wherein said drilling fluid flowing through said passage leaks passed said first and second lateral sides when said rotor is in said first circumferential orientation, and wherein said torque imparting means causes said leakage passed said first lateral side to be greater than said leakage through said second lateral side. 26. The rotary pulser according to claim 1, wherein said stator comprises at least one vane adjacent said passage, and wherein said rotor blade is partially aligned with both said vane and said passage when said rotor is in said first circumferential orientation. 27. The rotary pulser according to claim 1, wherein said stator comprises at least one vane adjacent said passage, and wherein said rotor blade is partially aligned with both said vane and said passage when said rotor is in said second circumferential orientation. 28. A rotary pulser for transmitting information from a portion of a drill string operating at a down hole location in a well bore, said drill string having a passage through which a drilling fluid flows, comprising: a) a housing adapted to be mounted in said drill string; b) a stator supported in said housing and having at least one approximately axially extending passage formed therein through which at least a portion of said drilling fluid flows; c) a rotor supported in said housing and located downstream of said stator, (i) said rotor having at least one blade extending radially outward so as to define a radial height thereof, said blade imparting a varying degree of obstruction to said flow of drilling fluid flowing through said stator passage depending on the circumferential orientation of said rotor, (ii) said rotor being rotatable into at least first and second circumferential orientations, said first rotor circumferential orientation providing a greater obstruction to said flow of drilling fluid than that of said second rotor circumferential orientation, whereby rotation of said rotor generates a series of pulses encoded with said information to be transmitted, (iii) said rotor blade having upstream and downstream surfaces defining a thickness therebetween, said rotor blade downstream surface extending in both the radial and circumferential directions, said rotor blade downstream surface being profiled over at least a major portion of said radial height of said blade so that (A) in transverse cross section said thickness of said rotor blade generally increases as said surface extends downstream and (B) in longitudinal cross section said thickness of said rotor blade generally decreases as said blade extends radially outward. 29. The rotary pulser according to claim 28, wherein over at least a major portion of said radial height said rotor blade downstream surface is inwardly tapered as it extends in the downstream direction. 30. The rotary pulser according to claim 28, wherein at least a major portion of said radial height said rotor blade has a shape in transverse cross-section formed by superimposing a thickened central rib onto a thinner plate-like portion. 31. The rotary pulser according to claim 30, wherein said plate-like portion forms first and second lateral sides of said blade and a substantially flat surface therebetween. 32. The rotary pulser according to claim 30, wherein said plate-like portion forms first and second lateral sides of said blade, and wherein said thickness of said plate-like portion proximate said first and second lateral sides is no more than approximately ¼ inch (6 mm) over at least a major portion of said radial height of said blade. 33. The rotary pulser according to claim 30, wherein the thickness of said central rib is tapered so as to become thinner as said blade extends radially outward. 34. The rotary pulser according to claim 28, wherein said rotor blade has first and second lateral sides defining a circumferential width of said rotor blade therebetween, and wherein said downstream surface of said rotor blade is profiled over at least a major portion of said radial height of said blade so that in transverse cross section said thickness of said rotor blade is at a minimum proximate said first and second lateral sides. 35. The rotary pulser according to claim 28, wherein. said rotor blade has first and second lateral sides, and wherein said thickness of said blade proximate said first and second lateral sides is no more than approximately ¼ inch (6 mm) over at least a major portion of said radial height of said blade. 36. The rotary pulser according to claim 35, wherein. said rotor blade has a radially outward tip, and wherein said thickness of said blade proximate said tip is no more than approximately ¼ inch (6 mm). 37. The rotary pulser according to claim 28, wherein said downstream surface of said rotor blade is profiled over at least a major portion of said radial height of said blade so that in transverse cross section said thickness of said rotor blade is at a maximum approximately midway between said first and second lateral sides. 38. The rotary pulser according to claim 28, wherein said rotor blade has first and second lateral sides defining the circumferential width of said rotor blade therebetween, wherein. said rotor blade downstream surface is profiled over at least a major portion of said radial height of said blade so that in transverse cross-section said thickness of said rotor blade generally decreases as said surface extends circumferentially in the both the clockwise and counterclockwise directions over at least a portion of the circumferential width of said blade. 39. The rotary pulser according to claim 28, wherein said rotor blade downstream surface is profiled so that said decrease in thickness as said blade extends radially outward is obtained by displacing said downstream surface in the upstream direction as said blade extends radially outward. 40. The rotary pulser according to claim 28, wherein said upstream surface of said rotor blade forms a substantially planar surface. 41. The rotary pulser according to claim 28, wherein said stator passage and said rotor blade each have a width in the circumferential direction, said circumferential width of said rotor blade being greater than said width of said stator passage. 42. The rotary pulser according to claim 28, wherein said stator passage comprises means for swirling said drilling fluid in a circumferential direction. 43. The rotary pulser according to claim 28, wherein said motor rotates said rotor in an oscillatory fashion in both clockwise and counterclockwise directions to generate said pulses. 44. The rotary pulser according to claim 28, wherein said motor rotates said rotor in a single direction to generate said pulses. 45. The rotary pulser according to claim 28, wherein said stator comprises at least one vane adjacent said passage, and wherein said rotor blade is aligned with said vane when said rotor is in said second circumferential orientation. 46. The rotary pulser according to claim 28, wherein said rotor blade is aligned with said passage when said rotor is in said first circumferential orientation. 47. The rotary pulser according to claim 46, wherein said rotor blade has first and second lateral sides, and wherein said drilling fluid flowing through said passage leaks passed said first and second lateral sides when said rotor is in said first circumferential orientation, and wherein said leakage passed said first lateral side is greater than said leakage through said second lateral side. 48. The rotary pulser according to claim 28, wherein said stator comprises at least one vane adjacent said passage, and wherein said rotor blade is aligned between said vane and said passage when said rotor is in said first circumferential orientation. 49. The rotary pulser according to claim 28, wherein said stator comprises at least one vane adjacent said passage, and wherein said rotor blade is aligned between said vane and said passage when said rotor is in said second circumferential orientation. 50. A rotary pulser for transmitting information from a portion of a drill string operating at a down hole location in a well bore, said drill string having a passage through which a drilling fluid flows, comprising: a) a housing adapted to be mounted in said drill string; b) a stator supported in said housing and having at least one approximately axially extending passage formed therein through which at least a portion of said drilling fluid flows; c) a rotor supported in said housing and located downstream of said stator, (i) said rotor having at least one blade extending radially outward so as to define a radial height thereof, said blade imparting a varying degree of obstruction to said flow of drilling fluid flowing through said stator passage depending on the circumferential orientation of said rotor, (ii) said rotor being rotatable into at least first and second circumferential orientations, said first rotor circumferential orientation providing a greater obstruction to said flow of drilling fluid than that of said second rotor circumferential orientation, whereby rotation of said rotor generates a series of pulses encoded with said information to be transmitted, (iii) said rotor blade having upstream and downstream surfaces defining a thickness therebetween, said rotor blade downstream surface extending in both the radial and circumferential directions, said rotor blade downstream surface being profiled over at least a major portion of the radial height of said blade so that said thickness generally decreases as said surface extends both radially upward and circumferentially outward from the center of said blade. 51. A rotary pulser for transmitting information from a portion of a drill string operating at a down hole location in a well bore, said drill string having a passage through which a drilling fluid flows, comprising: a) a housing adapted to be mounted in said drill string; b) a stator supported in said housing and having at least one approximately axially extending passage formed therein through which at least a portion of said drilling fluid flows; c) a rotor supported in said housing and located downstream of said stator, (i) said rotor having at least one radially outward extending blade, said blade imparting a varying degree of obstruction to said flow of drilling fluid flowing through said stator passage depending on the circumferential orientation of said rotor, (ii) said rotor being rotatable into at least first and second circumferential orientations, said first rotor circumferential orientation providing a greater obstruction to said flow of drilling fluid than that of said second rotor circumferential orientation, whereby rotation of said rotor generates a series of pulses encoded with said information to be transmitted; d) a motor coupled to said rotor for imparting rotation to said rotor, whereby operation of said motor generates said series of encoded pulses; and e) mechanical biasing means for imparting a torque to said rotor tending to rotate said rotor away from said first circumferential orientation when said motor is not rotating said rotor. 52. The rotary pulser according to claim 51, where said mechanical biasing means comprises a torsion spring having a first end coupled to said housing and a second end coupled to said rotor, said torsion spring is mounted so as to impose a torque on said shaft when said rotor is rotated away from said first circumferential orientation that drives said rotor back toward said second circumferential orientation. 53. A rotary pulser for transmitting information from a portion of a drill string operating at a down hole location in a well bore, said drill string having a passage through which a drilling fluid flows, comprising: a) a housing adapted to be mounted in said drill string; b) a stator supported in said housing and having at least one approximately axially extending passage formed therein through which at least a portion of said drilling fluid flows; c) a rotor supported in said housing and located downstream of said stator, said rotor having at least one radially outward extending blade, said blade imparting a varying degree of obstruction to said flow of drilling fluid flowing through said stator passage depending on the circumferential orientation of said rotor; and d) a replaceable wear sleeve disposed in said housing and enclosing said rotor. | FIELD OF THE INVENTION The current invention is directed to an improved rotary pulser for transmitting information from a down hole location in a well to the surface, such as that used in a mud pulse telemetry system employed in a drill string for drilling an oil well. BACKGROUND OF THE INVENTION In underground drilling, such as gas, oil or geothermal drilling, a bore is drilled through a formation deep in the earth. Such bores are formed by connecting a drill bit to sections of long pipe, referred to as a “drill pipe,” so as to form an assembly commonly referred to as a “drill string” that extends from the surface to the bottom of the bore. The drill bit is rotated so that it advances into the earth, thereby forming the bore. In rotary drilling, the drill bit is rotated by rotating the drill string at the surface. In directional drilling, the drill bit is rotated by a down hole mud motor coupled to the drill bit; the remainder of the drill string is not rotated during drilling. In a steerable drill string, the mud motor is bent at a slight angle to the centerline of the drill bit so as to create a side force that directs the path of the drill bit away from a straight line. In any event, in order to lubricate the drill bit and flush cuttings from its path, piston operated pumps on the surface pump a high pressure fluid, referred to as “drilling mud,” through an internal passage in the drill string and out through the drill bit. The drilling mud then flows to the surface through the annular passage formed between the drill string and the surface of the bore. Depending on the drilling operation, the pressure of the drilling mud flowing through the drill string will typically be between 1,000 and 25,000 psi. In addition, there is a large pressure drop at the drill bit so that the pressure of the drilling mud flowing outside the drill string is considerably less than that flowing inside the drill string. Thus, the components within the drill string are subject to large pressure forces. In addition, the components of the drill string are also subjected to wear and abrasion from drilling mud, as well as the vibration of the drill string. The distal end of a drill string, which includes the drill bit, is referred to as the “bottom hole assembly.” In “measurement while drilling” (MWD) applications, sensing modules in the bottom hole assembly provide information concerning the direction of the drilling. This information can be used, for example, to control the direction in which the drill bit advances in a steerable drill string. Such sensors may include a magnetometer to sense azimuth and accelerometers to sense inclination and tool face. Historically, information concerning the conditions in the well, such as information about the formation being drill through, was obtained by stopping drilling, removing the drill string, and lowering sensors into the bore using a wire line cable, which were then retrieved after the measurements had been taken. This approach was known as wire line logging. More recently, sensing modules have been incorporated into the bottom hole assembly to provide the drill operator with essentially real time information concerning one or more aspects of the drilling operation as the drilling progresses. In “logging while drilling” (LWD) applications, the drilling aspects about which information is supplied comprise characteristics of the formation being drilled through. For example, resistivity sensors may be used to transmit, and then receive, high frequency wavelength signals (e.g., electromagnetic waves) that travel through the formation surrounding the sensor. By comparing the transmitted and received signals, information can be determined concerning the nature of the formation through which the signal traveled, such as whether it contains water or hydrocarbons. Other sensors are used in conjunction with magnetic resonance imaging (MRI). Still other sensors include gamma scintillators, which are used to determine the natural radioactivity of the formation, and nuclear detectors, which are used to determine the porosity and density of the formation. In traditional LWD and MWD systems, electrical power was supplied by a turbine driven by the mud flow. More recently, battery modules have been developed that are incorporated into the bottom hole assembly to provide electrical power. In both LWD and MWD systems, the information collected by the sensors must be transmitted to the surface, where it can be analyzed. Such data transmission is typically accomplished using a technique referred to as “mud pulse telemetry.” In a mud pulse telemetry system, signals from the sensor modules are typically received and processed in a microprocessor-based data encoder of the bottom hole assembly, which digitally encodes the sensor data. A controller in the control module then actuates a pulser, also incorporated into the bottom hole assembly, that generates pressure pulses within the flow of drilling mud that contain the encoded information. The pressure pulses are defined by a variety of characteristics, including amplitude (the difference between the maximum and minimum values of the pressure), duration (the time interval during which the pressure is increased), shape, and frequency (the number of pulses per unit time). Various encoding systems have been developed using one or more pressure pulse characteristics to represent binary data (i.e., bit 1 or 0)—for example, a pressure pulse of 0.5 second duration represents binary 1, while a pressure pulse of 1.0 second duration represents binary 0. The pressure pulses travel up the column of drilling mud flowing down to the drill bit, where they are sensed by a strain gage based pressure transducer. The data from the pressure transducers are then decoded and analyzed by the drill rig operating personnel. Various techniques have been attempted for generating the pressure pulses in the drilling mud. One technique involves incorporating a pulser into the drill string in which the drilling mud flows through passages formed by a stator. A rotor, which is typically disposed upstream of the stator, is either rotated continuously, referred to as a mud siren, or is incremented, either by oscillating the rotor or rotating it incrementally in one direction, so that the rotor blades alternately increase and decrease the amount by which they obstruct the stator passages, thereby generating pulses in the drilling fluid. An oscillating type pulser valve is disclosed in U.S. Pat. No. 6,714,138 (Turner et al.), hereby incorporated by reference in its entirety. A prior art rotor used in a commercial embodiment of U.S. Pat. No. 6,714,138 (Turner et al.) is shown in FIG. 1. In that embodiment, the rotor was located upstream of the stator, as shown in U.S. Pat. No. 6,714,138 (Turner et al.), and was oriented with respect to the direction of the flow of drilling mud so that the downstream surface of the blade was a flat surface, with the upstream surface of the blade tapering so that the thickness at the radial tip of the blade was about ⅛ inch (3 mm). Unfortunately, in such prior pulsers, the flow of drilling mud creates pressure forces that tend to drive the rotor into a position in which the rotor blades provide the maximum obstruction to the flow of drilling mud. Consequently, if the motor driving the pulser fails, the flow induced torque will cause the rotor to remain stationary in the position of maximum obstruction, thereby interfering with flow of drilling mud, increasing the pressure of the drilling mud, and accelerating wear of the pulser components due to the high flow velocity through the obstructed passages. Moreover, even if the motor does not fail, during periods when the pulser is not operating, the flow induced torque will gradually overcome the rotor's resistance to rotation and obstruct the mud flow. Since this unnecessary obstruction to the flow of drilling mud is undesirable, the rotor position must be monitored and the pulser motor periodically employed to rotate the rotor into the position of minimum obstruction. This results in an unnecessary drain on the battery that powers the motor. According to one approach, described in U.S. Pat. No. 4,785,300 (Chin et al), the generation of a flow induced torque tending to rotate the rotor into the obstruction orientation may be prevented in certain pulsers by shaping rotor blades, located downstream of the stator, so that their sides are outwardly tapered, and thus become wider in the circumferential direction, as they extend in the downstream direction. However, this approach is not believed to be entirely satisfactory in many situations. Consequently, it would be desirable to provide a mud pulse telemetry system in which the rotor blades were prevented from unintentionally rotating into the obstructed position when the pulser was not being utilized to transmit information, without the need to operate the pulser motor. In addition, the portions of a pulser subject to the high velocity flow of drilling mud are subject to wear. Consequently, it would also be desirable to develop a pulser with increased resistance to wear in such high flow areas. SUMMARY OF THE INVENTION It is an object of the current invention to provide an improved apparatus for transmitting information from a portion of a drill string operating at a down hole location in a well bore to a location proximate the surface of the earth, the drill string having a passage through which a drilling fluid flows, comprising a rotary pulser having (i) a housing adapted to be mounted in the drill string, (ii) a stator supported in the housing and having at least one approximately axially extending passage formed therein through which at least a portion of the drilling fluid flows, (iii) a rotor supported in the housing adjacent the stator and downstream therefrom, the rotor having at least one blade extending radially outward so as to define a radial height thereof, the blade imparting a varying degree of obstruction to the flow of drilling fluid flowing through the stator passage depending on the circumferential orientation of the rotor, the rotor being rotatable into at least first and second circumferential orientations, the first rotor circumferential orientation providing a greater obstruction to the flow of drilling fluid than that of the second rotor circumferential orientation, whereby rotation of the rotor generates a series of pulses encoded with the information to be transmitted, (iv) a motor coupled to the rotor for imparting rotation to the rotor, whereby operation of the motor generates the series of encoded pulses, and (v) means for imparting a torque to reduce the obstruction imparted by the blade to the flow of drilling fluid when the motor is not operating to transmit the information by urging the rotor to rotate away from the first circumferential orientation and toward the second circumferential orientation. In one embodiment of the invention, a replaceable wear sleeve is disposed in the housing enclosing the rotor. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a prior art rotor. FIG. 2 is a diagram, partially schematic, showing a drilling operation employing the mud pulse telemetry system of the current invention. FIG. 3 is a schematic diagram of a mud pulser telemetry system according to the current invention. FIG. 4 is a diagram, partially schematic, of the mechanical arrangement of a pulser according to the current invention. FIGS. 5-7 are consecutive portions of a longitudinal cross-section through a portion of the bottom hole assembly of the drill string shown in FIG. 2 incorporating the pulser shown in FIG. 3. FIG. 9 is an end view of the annular shroud shown in FIG. 5. FIG. 10 is a cross-section of the annular shroud shown in FIG. 5 taken through line X-X shown in FIG. 9. FIGS. 11 and 12 are isometric and end views, respectively, of the stator shown in FIG. 5. FIGS. 13(a) and (b) are transverse cross-sections of the stator shown in FIG. 5 taken through line XIII-XIII shown in FIG. 12 showing the downstream rotor blade in two circumferential orientations. FIGS. 14 and 15 are isometric and elevation views, respectively, of the rotor shown in FIG. 5. FIG. 16 is a transverse cross-section of the rotor shown in FIG. 5 taken along line XVI-XVI shown in FIG. 15. FIGS. 17(a) to (d) are a series of transverse cross-sections through one of the blades of the rotor shown in FIG. 5 taken along lines (a)-(a) through (d)-(d) shown in FIG. 16. FIGS. 18(a), (b), and (c) are cross-sections of the pulser taken along line XVIII-XVIII shown in FIG. 5 with the rotor in three circumferential orientations—(a) maximum obstruction, (b) intermediate obstruction, and (c) minimum obstruction. FIG. 19 is a detailed view of the portion of FIG. 5 containing the torsion spring according to the current invention. FIG. 20 is an isometric view of the torsion spring shown in FIG. 5 installed on the coupling between the rotor shaft and the reduction gear. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS A drilling operation incorporating a mud pulse telemetry system according to the current invention is shown in FIG. 2. A drill bit 2 drills a bore hole 4 into a formation 5. The drill bit 2 is attached to a drill string 6 that, as is conventional, is formed of sections of piping joined together. As is also conventional, a mud pump 16 pumps drilling mud 18 downward through the drill string 6 and into the drill bit 2. The drilling mud 18 flows upward to the surface through the annular passage between the bore 4 and the drill string 6, where, after cleaning, it is recirculated back down the drill string by the mud pump 16. As is conventional in MWD and LWD systems, sensors 8, such as those of the types discussed above, are located in the bottom hole assembly portion 7 of the drill string 6. In addition, a surface pressure sensor 20, which may be a transducer, senses pressure pulses in the drilling mud 18. According to a preferred embodiment of the invention, a pulser device 22, such as a valve, is located at the surface and is capable of generating pressure pulses in the drilling mud. As shown in FIGS. 2 and 3, in addition to the sensors 8, the components of the mud pulse telemetry system according to the current invention include a conventional mud telemetry data encoder 24, a power supply 14, which may be a battery or turbine alternator, and a down hole pulser 12 according to the current invention. The pulser comprises a controller 26, which may be a microprocessor, a motor driver 30, which includes a switching device 40, a reversible motor 32, a reduction gear 46, a rotor 36 and stator 38. The motor driver 30, which may be a current limited power stage comprised of transistors (FET's and bipolar), preferably receives power from the power supply 14 and directs it to the motor 32 using pulse width modulation. Preferably, the motor is a brushed DC motor with an operating speed of at least about 600 RPM and, preferably, about 6000 RPM. The motor 32 drives the reduction gear 46, which is coupled to the rotor shaft 34. Although only one reduction gear 46 is shown, it should be understood that two or more reduction gears could also be utilized. Preferably, the reduction gear 46 achieves a speed reduction of at least about 144:1. The sensors 8 receive information 100 useful in connection with the drilling operation and provide output signals 102 to the data encoder 24. Using techniques well known in the art, the data encoder 24 transforms the output from the sensors 8 into a digital code 104 that it transmits to the controller 26. Based on the digital code 104, the controller 26 directs control signals 106 to the motor driver 30. The motor driver 30 receives power 107 from the power source 14 and directs power 108 to a switching device 40. The switching device 40 transmits power 111 to the appropriate windings of the motor 32 so as to effect rotation of the rotor 36 in either a first (e.g., clockwise) or opposite (e.g., counterclockwise) direction so as to generate pressure pulses 112 that are transmitted through the drilling mud 18. The pressure pulses 112 are sensed by the sensor 20 at the surface and the information is decoded and directed to a data acquisition system 42 for further processing, as is conventional. As shown in FIG. 3, preferably, both a down hole static pressure sensor 29 and a down hole dynamic pressure sensor 28 are incorporated into the drill string to measure the pressure of the drilling mud in the vicinity of the pulser 12, as described in the previously referenced U.S. Pat. No. 6,714,138 (Turner et al.). The pressure pulsations sensed by the dynamic pressure sensor 28 may be the pressure pulses generated by the down hole pulser 12 or the pressure pulses generated by the surface pulser 22. In either case, the down hole dynamic pressure sensor 28 transmits a signal 115 to the controller 26 containing the pressure pulse information, which may be used by the controller in generating the motor control signals 106. The down hole pulser 12 may also include an orientation encoder 47 suitable for high temperature applications, coupled to the motor 32. The orientation encoder 47 directs a signal 114 to the controller 26 containing information concerning the angular orientation of the rotor 36. Information from the orientation encoder 47 can be used to monitor the position of the rotor 36 during periods when the pulser 12 is not in operation and may also be used by the controller during operation in generating the motor control signals 106. Preferably, the orientation encoder 47 is of the type employing a magnet coupled to the motor shaft that rotates within a stationary housing in which Hall effect sensors are mounted that detect rotation of the magnetic poles. A preferred mechanical arrangement of the down hole pulser 12 is shown schematically in FIG. 4 and in more detail in FIGS. 5-7. FIG. 5 shows the upstream portion of the pulser, FIG. 6 shows the middle portion of the pulser, and FIG. 7 shows the downstream portion of the pulser. The construction of the middle and downstream portions of the pulser is described in the previously referenced U.S. Pat. No. 6,714,138 (Turner et al.). As previously discussed, the outer housing of the drill string 6 is formed by a section of drill pipe 64, which forms the central passage 62 through which the drilling mud 18 flows. As is conventional, the drill pipe 64 has threaded couplings on each end, shown in FIGS. 5 and 7, that allow it to be mated with other sections of drill pipe. The housing for the pulser 12 is comprised of an annular shroud 39, and housing portions 66, 68, and 69, and is mounted within the passage 62 of the drill pipe section 64. As shown in FIG. 5, the upstream end of the pulser 12 is mounted in the passage 62 by the annular shroud 39. As shown in FIG. 7, the downstream end of the pulser 12 is attached via coupling 180 to a centralizer 122 that further supports it within the passage 62. The annular shroud 39, shown in FIGS. 9 and 10, comprises a sleeve portion 120 forming a shroud for the rotor 36 and stator 38, as discussed below, and an end plate 121. As shown in FIG. 5, tungsten carbide wear sleeves 33 enclose the rotor 36 and protect the inner surface of the shroud 39 from wear as a result of contact with the drilling mud. Passages 123 are formed in the end plate 121 that allow drilling mud 18 to flow through the shroud 39. The shroud is fixed within the drill pipe 64 by a set screw (not shown) that is inserted into a hole 85 in the drill pipe. As shown in FIG. 5, a nose 61 forms the forward most portion of the pulser 12. The nose 61 is attached to a stator retainer 67, shown in FIG. 8. The rotor 36 and stator 38 are mounted within the shroud 39. According to one aspect of the invention, the rotor 36 is located downstream of the stator 38. The stator retainer 67 is threaded into the upstream end of the annular shroud 39 and restrains the stator 38 and the wear sleeves 33 from axial motion by compressing them against a shoulder 57 formed in the shroud 39. Thus, the wear sleeves 33 can be replaced as necessary. Moreover, since the stator 38 and wear sleeves 33 are not highly loaded, they can be made of a brittle, wear resistant material, such as tungsten carbide, while the shroud 39, which is more heavily loaded but not as subject to wear from the drilling fluid, can be made of a more ductile material, such as 17-4 stainless steel. The rotor 36 is driven by a drive train mounted in the pulser housing and includes a rotor shaft 34 mounted on upstream and downstream bearings 56 and 58 in a chamber 63. The chamber 63 is formed by upstream and downstream housing portions 66 and 68 together with a seal 60 and a barrier member 110 (as used herein, the terms upstream and downstream refer to the flow of drilling mud toward the drill bit). The seal 60 is a spring loaded lip seal. The chamber 63 is filled with a liquid, preferably a lubricating oil, that is pressurized to an internal pressure that is close to that of the external pressure of the drilling mud 18 by a piston 162 mounted in the upstream oil-filed housing portion 66. The upstream and downstream housing portions 66 and 68 that form the oil filled chamber 63 are threaded together, with the joint being sealed by O-rings 193. As previously discussed, the rotor 36 is preferably located immediately downstream of the stator 38. The upstream face 72 of the rotor 36 is spaced from the downstream face 71 of the stator 38 by shims, not shown. Since, as discussed below, the upstream surface 72 of the rotor 36 is substantially flat, the axial gap between the stator outlet face 71 and the rotor upstream surface is substantially constant over the radial height of a blade 74. Preferably the axial gap between the upstream rotor face 72 and the downstream stator face 71 is approximately 0.030-0.060 inch (0.75-1.5 mm). The rotor 36 includes a rotor shaft 34, which is mounted within the oil-filled chamber 63 by the upstream and downstream bearings 58 and 56. The downstream end of the rotor shaft 34 is attached by a coupling 182 to the output shaft of the reduction gear 46, which may be a planetary type gear train, such as that available from Micromo, of Clearwater, Fla., and which is also mounted in the downstream oil-filled housing portion 68. The input shaft 113 to the reduction gear 46 is supported by a bearing 54 and is coupled to inner half 52 of a magnetic coupling 48, such as that available through Ugimag, of Valparaiso, Ind. In operation, the motor 32 rotates a shaft 94 which, via the magnetic coupling 48, transmits torque through a housing barrier 110 that drives the reduction gear input shaft 113. The reduction gear drives the rotor shaft 34, thereby rotating the rotor 36. The outer half 50 of the magnetic coupling 48 is mounted within housing portion 69, which forms a chamber 65 that is filled with a gas, preferably air, the chambers 63 and 65 being separated by the barrier 110. The outer magnetic coupling half 50 is coupled to a shaft 94 which is supported on bearings 55. A flexible coupling 90 couples the shaft 94 to the electric motor 32, which rotates the drive train. The orientation encoder 47 is coupled to the motor 32. The down hole dynamic pressure sensor 28 is mounted on the drill pipe 64. As shown in FIGS. 11 and 12, the stator 38, which is preferably made of tungsten carbide for wear resistance, is comprised of a hub 43, an outer rim 41, and vanes 31 extending therebetween that form axial passages 80 for the flow of drilling mud. Locating pins (not shown) extend into grooves 37 in the rim 41, shown in FIG. 11, to circumferentially orient the stator 38 with respect to the remainder of the pulser. According to one aspect of the invention, the stator 38 preferably swirls the drilling mud 18 as it flows through the passages 180. As shown in FIG. 13, this swirling is preferably accomplished by inclining one of the walls 80′ of the passage 80 at an angle A to the axial direction. The angle A preferably increases as the passage 80 extends radially outward and is preferably in the range of approximately 10° to 15°. The other wall 80″ of the passage 180 is oriented in a plane parallel to the central axis so that the circumferential width Wi of the passage 80 at the inlet face 70 of the stator 38 is larger than the width Wo at the outlet face 71. However, both walls of the passages could also be inclined if preferred. As shown in FIGS. 14-16, the rotor 36 is comprised of a central hub 77 from which a plurality of blades 74 extend radially outward, the radial height of the blades being indicated by h in FIG. 15. As discussed further below, the blades 74 are capable of imparting a varying obstruction to the flow of drilling mud 18 depending on the circumferential orientation of the rotor 36 relative to the stator 38. Although four blades are shown in the figures, a greater or lesser number of blades could also be utilized. Each blade 74 has first and second lateral sides 75 and 76 that define the circumferential width Wb of the blade. Preferably, the circumferential width Wb of the blades 74 is slightly larger, preferably at least 1% larger, than the circumferential width Wo at the stator outlet face 71 immediately upstream of the rotor 36. The surface 72, of the rotor 36 including the blades 74, preferably lies substantially in a plane so that it is substantially flat. In contrast to the prior art rotor shown in FIG. 1, according to one aspect of the invention, the rotor 36 is oriented so that the planar surface 72 forms the upstream surface of the rotor. However, provided that it forms an adequate obstruction to the flow of drilling mud for purposes of pulse generation, the shape of the upstream surface of the rotor blades 74 is not critical to the present invention and shapes other than flat surfaces can also be employed. As shown in FIG. 16, the lateral sides 75 and 76 of the rotor blades 74 form an acute angle so that the blades become wider in the circumferential direction as they extend radially outward. Of more importance for present purposes, in longitudinal cross section, the blades 74 are shaped so as to become thinner in the axial direction as they extend radially outward, as shown in FIG. 15. This radial thinning is accomplished by shaping the profile of the blade downstream surface 73 so that the surface extends axially upstream as it extends radially outward (the direction of flow of the drilling mud 18 with respect to the rotor is indicated by the arrows in FIG. 15). Comparison of transverse cross-sections through the blade 74 at four radial locations, shown in FIGS. 17(a)-(d), shows that the maximum blade thickness in the axial direction dm (indicated in FIG. 17(c)) is greatest at the hub of the blade (FIG. 17(a)) and decreases to a minimum at the tip (FIG. 17(d)), with the decrease in thickness resulting from the downstream surface 73 being displaced axially forward as it extends radially upward. The thickness de adjacent the lateral sides 75 and 76 (indicated in FIG. 17(d)) similarly thins down as the blade 74 extends radially outward. As shown in the transverse cross sections through the blade 74 shown in FIGS. 17(a)-(c), over a least a major portion—i.e., at least one half—of the radial height of the blade, and more preferably throughout the entirety of the radial height of the blade except the portion adjacent the radially outward tip 83 (shown in FIG. 17(d)), the downstream surface 73 is profiled so that it projects downstream as its extends circumferentially inward from the lateral sides 75 and 76 toward the center of the blade—that is, the blades are inwardly tapered in the downstream direction. Thus over this portion of the blade, its downstream surface 73 is not only radially tapered but is also circumferentially tapered so that the thickness is a maximum at the center of the blade, midway between the lateral sides 75 and 76, and becomes thinner as the surface extends circumferentially outward in both the clockwise and counterclockwise directions, reaching a minimum thickness de adjacent the lateral sides. Thus, over a least a major portion of the radial height of the blade 74, and more preferably throughout the entirety of the radial height of the blade except the portion adjacent the radially outward tip 83, at a given transverse cross section, the thickness of the blade in the axial direction is tapered so as to become thicker as the surface 73 extends in the downstream direction. Further, over this portion of the blade, the circumferential width of the blade decreases as the blade extends in the axial direction, from ci at the blade upstream surface 72 to co at the downstream most portion of the downstream surface 73, as shown in FIG. 17(a)-(c). As shown best in FIGS. 14 and 17, except at the tip 83, in transverse cross-section, the shape of each blade 74 is formed by superimposing a relatively thickened central rib 78′ onto a relatively thinner flat plate-like portion 78″, with the plate-like portion 78″ located upstream of the central rib 78′. The plate-like portion 78″ forms the lateral sides 75 and 76 of the blade. The central rib 78′ has tapered portions 79 on either side so as to blend into the surface 81 of the plate-like portion 78″. Preferably, the central rib 78′, and to a lesser extent the plate-like portion 78″, are tapered as the blade extends radially outward so that the maximum thickness of the blade dm decreases as the blade extends radially outward, as discussed above. Preferably, the thickness of the blade is tapered in the circumferential direction so that at a given transverse cross section, such as those shown in FIG. 17, the maximum thickness of the blade dm is at least twice the thickness de adjacent the lateral sides 75 and 76 over at least a major portion of the radial height of the blade 74, and more preferably throughout the entirety of the radial height of the blade except the portion adjacent the radially outward tip 83. In the approximately outer two-thirds of the blade, the surfaces 81 adjacent the lateral sides 75 and 76 are substantially flat. However, of most importance is the fact that the thickness de at the lateral sides 75 and 76 and the thickness dt at the radial tip 83 are relatively thin. Preferably the thickness adjacent the lateral sides 75 and 76 de and the tip 83 dt should be not more than about ¼ inch (6 mm) thick and, more preferably, not more than about ⅛ inch (3 mm), over a major portion of the radial height of the blade. The thickness could be reduced essentially to zero so that the lateral sides and tip were formed by sharp edges. By shaping the blade downstream surface 73 so that it tapers in both the radial and circumferential directions, having a maximum thickness in the center of the blade hub and becoming thinner as the blade extends both radially and circumferentially outward, so as to form a tapered central rib 78, sufficient mechanical strength is imparted to the blade 74 while minimizing the thickness of the blade at its edges, thereby improving the hydrodynamic performance of the blade, as discussed below. Preferably, the profiling of the downstream surface 73 is such that the taper in the thickness is achieved smoothly and gradually without abrupt steps in thickness, as shown in FIGS. 17(a)-(c). In operation, a pulse is created in the drilling mud 18 by rotating the rotor 36 into a first circumferential orientation that results in a reduced, or minimum, obstruction to the flow of drilling mud, such as shown in FIG. 18(c) in which the rotor blades 74 are axially aligned with the stator vanes 31, then rotating the rotor into a second circumferential orientation that results in an increased, or maximum, obstruction, such as shown in FIGS. 18(a) and 13(a) in which the rotor blades are axially aligned with the stator passages 80, then again rotating the rotor into an orientation in which the rotor blades are aligned with the stator vanes so as to result in the minimum obstruction. This last step is achieved by either reversing the prior rotation of the rotor or rotating it further in the same direction. This process is then repeated, as necessary, to create a series of pressure pulses encoded with the information to be transmitted to the surface, for example, using the methodology discussed in the aforementioned U.S. Pat. No. 6,714,138 (Turner et al.). Although FIGS. 18(a) and (c) show the rotor 36 in orientations that result in the maximum and minimum obstructions achievable through rotation of the rotor, it should be understood that pulses can be created by rotating the rotor into and/or out of orientations intermediate of those shown in FIGS. 18(a) and (c), such as the intermediate circumferential orientation shown in FIGS. 18(b) and 13(b). Consequently, the pulse generating scheme could involve rotating the rotor 36 into and/or out of orientations resulting in obstructions less than the maximum and minimum obtainable. Note that, as shown in FIG. 18, preferably the radial height of the rotor blades 74 is less than that of the stator passages 38 so that the blades cannot completely obstruct the flow of drilling mud 18. In addition, the axial gap between the downstream face 71 of the stator 38 and the upstream surface 72 of the rotor 36 will ensure that the flow of drilling mud 18 will never be completely obstructed. In one embodiment, pulses are created operating the motor 32 to place the rotor 36 into the circumferential orientation shown in FIG. 18(c) in which the rotor blades 74 are aligned with the stator vanes 31 so that the obstruction to the flow of drilling mud 18 is a minimum, then operating the motor to rotate the rotor clockwise (when looking against the direction of flow) about 45°, through the orientation shown in FIG. 18(b), thereby increasing the obstruction, and into the orientation shown in FIG. 18(a) in which the rotor blades are aligned with the stator passages 80 so that the obstruction to the flow reaches its maximum, and then reversing the operation of the motor to rotate the rotor in the counterclockwise direction 45° so as to return to the minimum obstruction orientation shown in FIG. 18(c). This motor driven oscillation between the minimum and maximum obstructions is repeated as necessary to transmit the encoded information. Mechanical stops 59, which engage a relief in the rotor shaft, limit the maximum rotation of the rotor to about 55° so that, although playing no role in the generation of pulses by the motor 32, these stops ensure that the rotation of the rotor when the pulser is not in operation is limited to approximately 5° beyond the minimum and maximum obstruction orientations. When using a prior art rotor, such as that shown in FIG. 1, the drilling mud 18 imposed a closing torque on the rotor tending to rotate it counterclockwise from the minimum flow orientation shown in FIG. 18(c) into the orientation of maximum obstruction shown in FIG. 18(a) when the motor 32 was not controlling the rotation of the rotor during pulse generation, as previously discussed. Surprisingly, it has been found that the design described above does not result in the creation of such flow induced closing torque. In fact, it has been found that, not only does the current invention eliminate the closing torque, it results in the creation of an opening torque, indicated by F in FIGS. 13(a) and (b), that tends to rotate the rotor blades 74 away from the orientation of maximum obstruction into an orientation of lesser obstruction. In one embodiment, the rotor 36 achieves a stable circumferential orientation—that is, one in which the flow does not impose a torque on the rotor in either direction that is sufficient to overcome its resistance to rotation, so that the rotor will stably remain at such an orientation—that is approximately half way between that shown in FIGS. 18(b) and 18(c)—that is, only about one-quarter obstructed. The primary contributors to this hydrodynamic effect are believed to be (i) the locating of the rotor 36 immediately downstream of the stator 38, and (ii) the shaping of the rotor blade downstream surfaces 73 so that the blade thickness tapers as the blade extends outward in the circumferential direction from its center, thereby forming a relatively thin structure adjacent the lateral sides 75 and 76. Although not necessary to practice the current invention, in the optimal design, additional contributions to this effect are also believed to result from (i) the tapering of the blade as it extends outward in the radial direction, thereby forming relatively thin radial tips 83, (ii) the swirling of the drilling mud 18 by the stator passages 80 as shown in FIG. 13, and (iii) the control of leakage around the lateral sides of the rotor blades, as discussed below. With respect to the swirling of the drilling mud 18, contrary to what might be expected, it has been found that swirling the drilling mud in the clockwise direction prior to its introduction into the rotor 36 increases the opening torque F on the rotor blades in the counterclockwise direction, thereby tending to rotate the rotor away from an orientation of maximum obstruction and toward an orientation of minimum obstruction, as indicated in FIG. 13(b). With respect to the control of side leakage, it has been found that a benefit can be obtained by controlling the leakage of drilling mud passed the rotor blades when the rotor is in the orientation of maximum obstruction so that the leakage is less around one lateral side—the side facing the direction in which the rotor can rotate into an orientation of lesser obstruction—than the other lateral side. Preferably, the mechanical stops 59 are located such that the rotor will never rotate in the clockwise direction (i.e., to the right in FIG. 13) beyond the maximum obstruction orientation into an orientation in which the leakage of drilling mud 18′ around the counterclockwise most lateral side 75 of the rotor blade 74 is less than that around the clockwise most lateral side 76, as shown in FIG. 13(a). This can preferably be achieved by sizing of the width Wb of the rotor blades 74 in the circumferential direction so as to be slightly larger than the width Wo of the stator passages in the outlet face 70 of the stator 38, so that when the rotor is against the stop near the maximum obstruction orientation, the counterclockwise most lateral side 75 of the blade 74 extends beyond the counterclockwise most wall 80′ of the passage 80 further than the clockwise most lateral side 76 of blade extends beyond the clockwise most wall 80″, as shown in FIG. 13(a). The additional overlap of the blade 74 with respect to the stator vane 31 at the counterclockwise most lateral side 75 ensures that the leakage 18′ passed the counterclockwise most lateral side 75 is less than the leakage 18″ passed the clockwise most lateral side 76, which aids in the creation of the flow induced opening torque that rotates the rotor 36 counterclockwise from the maximum obstruction orientation shown in FIGS. 13(a) and 18(a) toward the orientations shown in FIGS. 13(b) and 18(b) and (c). Although, ideally, the flow induced opening torque created by the current invention is such that the minimum obstruction orientation shown in FIG. 18(c) is a stable orientation, this may not always be achieved. For example, the stable orientation may be the one-quarter open orientation, as previously discussed. Consequently, although not necessary to practice the invention, according to another aspect of the invention, in addition to the creation of the flow induced opening torque, the rotor 36 may also be mechanically biased toward the minimum obstruction orientation. Preferably, such mechanical bias is obtained by incorporating a torsion spring 172 between the shafting and the pulser housing 66, as shown in FIGS. 19 and 20. Preferably, the torsion spring 172 is mounted on the coupling 182 between the rotor shaft 34 and the reduction gear 46. One end 173 of the spring 172 is held in place by a groove 174 in the coupling 182 so as to be coupled to the rotor 36, while the other end 175 of the spring is held in place by a recess in the housing 66. Rotation of the coupling 182 relative to the housing 66 causes the spring to impart a resisting torque to the coupling. In the embodiment of the invention previously discussed, the torsion spring 172 is mounted so that it imparts a torque that combines with the flow induced opening torque when the rotor is in the maximum obstruction orientation to drive the rotor toward the minimum obstruction orientation. Further, the torsion spring 172 continues to impart a mechanical opening torque after the flow induced opening torque becomes insufficient to further rotate the rotor passed the one-quarter closed orientation shown in FIGS. 13(b) and 18(b) that drives the rotor 36 into the minimum obstruction orientation, shown in FIG. 18(c). The torsion spring 172 imparts an increasing torque as the rotor rotates clockwise away from the minimum obstruction orientation that urges it to return to the minimum obstruction orientation. Thus, although the flow induced opening torque would otherwise cause the stable orientation of the rotor to be about halfway between FIGS. 18(b) and (c)—about one-quarter open—as previously discussed, the addition of the mechanical torque supplied by the torsion spring 172 results in the stable orientation being the minimum obstruction orientation shown in FIG. 18(c). If the pulser were constructed so that the minimum orientation was otherwise a stable orientation—that is, the flow induced torque alone was sufficient to maintain the rotor in the minimum obstruction orientation—the torsion spring 172 could be installed so that it imparted no torque when the rotor was in the minimum obstruction orientation and a torque tending to return the rotor to the minimum obstruction orientation whenever the rotor rotated away from that orientation. Although the mechanical biasing of the rotor is preferably additive to the flow induced opening torque, the invention could also be practiced by employing mechanical biasing alone, such as by the torsion spring 172, while using a rotor having conventional hydrodynamic performance in which the flow induced torque tended to rotate the rotor into the maximum obstruction orientation. Although the current invention has been illustrated by reference to certain specific embodiments, those skilled in the art, armed with the foregoing disclosure, will appreciate that many variations could be employed. For example, although the invention has been discussed in detail with reference to an oscillating type rotary pulser, the invention could also be utilized in a pulser that generated pulses by rotating a rotor in only one direction. Thus, for example, reference to a rotor “circumferential orientation” that results in a minimum obstruction to the flow of drilling fluid applies to any orientation in which the rotor blades 36 are axially aligned with the stator vanes so that, for example, in the structure shown in FIG. 18 in which the stator vanes 31 are spaced at 90° intervals, both the rotor orientation shown in FIG. 18(c) as well as an orientation in which the rotor was rotated 90°, 180°, and 270° therefrom would all be considered as a single, or first, circumferential orientation since in each of these cases the rotor blades would be axially aligned with the stator vanes. Similarly, both the rotor orientation shown in FIG. 18(a) as well as an orientation that was 90°, 180°, and 270° therefrom would all be considered as a single, or second, circumferential orientation since in each of these cases the rotor blades would be axially aligned with the stator passages 80. Therefore, it should be appreciated that the current invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>In underground drilling, such as gas, oil or geothermal drilling, a bore is drilled through a formation deep in the earth. Such bores are formed by connecting a drill bit to sections of long pipe, referred to as a “drill pipe,” so as to form an assembly commonly referred to as a “drill string” that extends from the surface to the bottom of the bore. The drill bit is rotated so that it advances into the earth, thereby forming the bore. In rotary drilling, the drill bit is rotated by rotating the drill string at the surface. In directional drilling, the drill bit is rotated by a down hole mud motor coupled to the drill bit; the remainder of the drill string is not rotated during drilling. In a steerable drill string, the mud motor is bent at a slight angle to the centerline of the drill bit so as to create a side force that directs the path of the drill bit away from a straight line. In any event, in order to lubricate the drill bit and flush cuttings from its path, piston operated pumps on the surface pump a high pressure fluid, referred to as “drilling mud,” through an internal passage in the drill string and out through the drill bit. The drilling mud then flows to the surface through the annular passage formed between the drill string and the surface of the bore. Depending on the drilling operation, the pressure of the drilling mud flowing through the drill string will typically be between 1,000 and 25,000 psi. In addition, there is a large pressure drop at the drill bit so that the pressure of the drilling mud flowing outside the drill string is considerably less than that flowing inside the drill string. Thus, the components within the drill string are subject to large pressure forces. In addition, the components of the drill string are also subjected to wear and abrasion from drilling mud, as well as the vibration of the drill string. The distal end of a drill string, which includes the drill bit, is referred to as the “bottom hole assembly.” In “measurement while drilling” (MWD) applications, sensing modules in the bottom hole assembly provide information concerning the direction of the drilling. This information can be used, for example, to control the direction in which the drill bit advances in a steerable drill string. Such sensors may include a magnetometer to sense azimuth and accelerometers to sense inclination and tool face. Historically, information concerning the conditions in the well, such as information about the formation being drill through, was obtained by stopping drilling, removing the drill string, and lowering sensors into the bore using a wire line cable, which were then retrieved after the measurements had been taken. This approach was known as wire line logging. More recently, sensing modules have been incorporated into the bottom hole assembly to provide the drill operator with essentially real time information concerning one or more aspects of the drilling operation as the drilling progresses. In “logging while drilling” (LWD) applications, the drilling aspects about which information is supplied comprise characteristics of the formation being drilled through. For example, resistivity sensors may be used to transmit, and then receive, high frequency wavelength signals (e.g., electromagnetic waves) that travel through the formation surrounding the sensor. By comparing the transmitted and received signals, information can be determined concerning the nature of the formation through which the signal traveled, such as whether it contains water or hydrocarbons. Other sensors are used in conjunction with magnetic resonance imaging (MRI). Still other sensors include gamma scintillators, which are used to determine the natural radioactivity of the formation, and nuclear detectors, which are used to determine the porosity and density of the formation. In traditional LWD and MWD systems, electrical power was supplied by a turbine driven by the mud flow. More recently, battery modules have been developed that are incorporated into the bottom hole assembly to provide electrical power. In both LWD and MWD systems, the information collected by the sensors must be transmitted to the surface, where it can be analyzed. Such data transmission is typically accomplished using a technique referred to as “mud pulse telemetry.” In a mud pulse telemetry system, signals from the sensor modules are typically received and processed in a microprocessor-based data encoder of the bottom hole assembly, which digitally encodes the sensor data. A controller in the control module then actuates a pulser, also incorporated into the bottom hole assembly, that generates pressure pulses within the flow of drilling mud that contain the encoded information. The pressure pulses are defined by a variety of characteristics, including amplitude (the difference between the maximum and minimum values of the pressure), duration (the time interval during which the pressure is increased), shape, and frequency (the number of pulses per unit time). Various encoding systems have been developed using one or more pressure pulse characteristics to represent binary data (i.e., bit 1 or 0 )—for example, a pressure pulse of 0.5 second duration represents binary 1, while a pressure pulse of 1.0 second duration represents binary 0. The pressure pulses travel up the column of drilling mud flowing down to the drill bit, where they are sensed by a strain gage based pressure transducer. The data from the pressure transducers are then decoded and analyzed by the drill rig operating personnel. Various techniques have been attempted for generating the pressure pulses in the drilling mud. One technique involves incorporating a pulser into the drill string in which the drilling mud flows through passages formed by a stator. A rotor, which is typically disposed upstream of the stator, is either rotated continuously, referred to as a mud siren, or is incremented, either by oscillating the rotor or rotating it incrementally in one direction, so that the rotor blades alternately increase and decrease the amount by which they obstruct the stator passages, thereby generating pulses in the drilling fluid. An oscillating type pulser valve is disclosed in U.S. Pat. No. 6,714,138 (Turner et al.), hereby incorporated by reference in its entirety. A prior art rotor used in a commercial embodiment of U.S. Pat. No. 6,714,138 (Turner et al.) is shown in FIG. 1 . In that embodiment, the rotor was located upstream of the stator, as shown in U.S. Pat. No. 6,714,138 (Turner et al.), and was oriented with respect to the direction of the flow of drilling mud so that the downstream surface of the blade was a flat surface, with the upstream surface of the blade tapering so that the thickness at the radial tip of the blade was about ⅛ inch (3 mm). Unfortunately, in such prior pulsers, the flow of drilling mud creates pressure forces that tend to drive the rotor into a position in which the rotor blades provide the maximum obstruction to the flow of drilling mud. Consequently, if the motor driving the pulser fails, the flow induced torque will cause the rotor to remain stationary in the position of maximum obstruction, thereby interfering with flow of drilling mud, increasing the pressure of the drilling mud, and accelerating wear of the pulser components due to the high flow velocity through the obstructed passages. Moreover, even if the motor does not fail, during periods when the pulser is not operating, the flow induced torque will gradually overcome the rotor's resistance to rotation and obstruct the mud flow. Since this unnecessary obstruction to the flow of drilling mud is undesirable, the rotor position must be monitored and the pulser motor periodically employed to rotate the rotor into the position of minimum obstruction. This results in an unnecessary drain on the battery that powers the motor. According to one approach, described in U.S. Pat. No. 4,785,300 (Chin et al), the generation of a flow induced torque tending to rotate the rotor into the obstruction orientation may be prevented in certain pulsers by shaping rotor blades, located downstream of the stator, so that their sides are outwardly tapered, and thus become wider in the circumferential direction, as they extend in the downstream direction. However, this approach is not believed to be entirely satisfactory in many situations. Consequently, it would be desirable to provide a mud pulse telemetry system in which the rotor blades were prevented from unintentionally rotating into the obstructed position when the pulser was not being utilized to transmit information, without the need to operate the pulser motor. In addition, the portions of a pulser subject to the high velocity flow of drilling mud are subject to wear. Consequently, it would also be desirable to develop a pulser with increased resistance to wear in such high flow areas. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the current invention to provide an improved apparatus for transmitting information from a portion of a drill string operating at a down hole location in a well bore to a location proximate the surface of the earth, the drill string having a passage through which a drilling fluid flows, comprising a rotary pulser having (i) a housing adapted to be mounted in the drill string, (ii) a stator supported in the housing and having at least one approximately axially extending passage formed therein through which at least a portion of the drilling fluid flows, (iii) a rotor supported in the housing adjacent the stator and downstream therefrom, the rotor having at least one blade extending radially outward so as to define a radial height thereof, the blade imparting a varying degree of obstruction to the flow of drilling fluid flowing through the stator passage depending on the circumferential orientation of the rotor, the rotor being rotatable into at least first and second circumferential orientations, the first rotor circumferential orientation providing a greater obstruction to the flow of drilling fluid than that of the second rotor circumferential orientation, whereby rotation of the rotor generates a series of pulses encoded with the information to be transmitted, (iv) a motor coupled to the rotor for imparting rotation to the rotor, whereby operation of the motor generates the series of encoded pulses, and (v) means for imparting a torque to reduce the obstruction imparted by the blade to the flow of drilling fluid when the motor is not operating to transmit the information by urging the rotor to rotate away from the first circumferential orientation and toward the second circumferential orientation. In one embodiment of the invention, a replaceable wear sleeve is disposed in the housing enclosing the rotor. | 20040709 | 20080205 | 20060216 | 73237.0 | H04H900 | 0 | YACOB, SISAY | ROTARY PULSER FOR TRANSMITTING INFORMATION TO THE SURFACE FROM A DRILL STRING DOWN HOLE IN A WELL | SMALL | 0 | ACCEPTED | H04H | 2,004 |
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10,888,527 | ACCEPTED | Output control system for engine with exhaust control function | An engine output control system includes an engine ECU having a fundamental ignition timing map, a fundamental fuel injection quantity map, a target throttle angle determination unit for determining a target throttle angle of an exhaust control valve, an exhaust control valve diagnosis unit for diagnosing operation of the exhaust control valve, an ignition timing map to be used during an abnormality for determining fundamental ignition timing when the exhaust control valve operates abnormally, and an abnormal fuel injection thinning-out table for determining a reduced rate of fuel injection when the exhaust control valve has been diagnosed as abnormal. The exhaust control valve driving unit supplies a driving current to an actuator in such a manner that the target throttle angle notified by the engine ECU coincides with actual valve throttle angle. The system is capable of obtaining sufficient traveling performance even when an exhaust control valve has is operating abnormally. | 1. An output control system for an engine in which midway in an exhaust passage for guiding exhaust gas from an engine, there has been arranged an exhaust control valve for making an exhaust gas cross-sectional area thereof variable, the output control system comprising: diagnosis means for diagnosing whether or not said exhaust control valve is operating normally; and output limiting means for lowering the engine output when an operation of said exhaust control valve is diagnosed as abnormal. 2. The output control system according to claim 1, wherein said output limiting means controls at least one of ignition timing and fuel injection quantity so as to lower the engine output. 3. The output control system according to claim 2, wherein said output limiting means retards ignition timing as compared with a fundamental ignition timing for the engine. 4. The output control system according to claim 2, wherein said output limiting means reduces a rate of fuel injections to the engine. 5. The output control system according to claim 1, further comprising a display which indicates when an operation of said exhaust control valve is diagnosed as abnormal. 6. The output control system according to claim 2, further comprising a display which indicates when an operation of said exhaust control valve is diagnosed as abnormal. 7. The engine exhaust control device according to claim 3, further comprising a display which indicates when an operation of said exhaust control valve is diagnosed as abnormal. 8. An output control system for an engine comprising an exhaust control valve, wherein the exhaust control valve is positioned within an exhaust passage for guiding exhaust gas from an engine such that it lies between the engine and a muffler, the exhaust control valve providing variability in a cross sectional area of the exhaust passage, and including a throttle variably angularly positioned within the exhaust passage, in a normal operating range between a maximum throttle angle and a minimum throttle angle, an actuator for actuating the throttle within the exhaust control valve, diagnosis means for diagnosing whether or not said exhaust control valve is operating normally; and output limiting means for lowering the engine output when an operation of said exhaust control valve is diagnosed as operating abnormally. 9. The output control system of claim 8 wherein the diagnosis means determines a difference between a target throttle angle and an actual throttle angle, wherein when the difference is greater than a predetermined level, then the diagnosis means determines that the exhaust control valve is operating abnormally. 10. The output control system of claim 8 wherein the diagnosis means determines a difference between a target throttle angle and an actual throttle angle, wherein when an absolute value of the difference is greater than a predetermined level, then the diagnosis means determines that the exhaust control valve is operating abnormally. 11. The output control system of claim 8 wherein the diagnosis means compares an actuator driving current and a predetermined allowable current, wherein when the actuator driving current exceeds the predetermined allowable current, then the diagnosis means determines that the exhaust control valve is operating abnormally. 12. The output control system of claim 8 wherein said output limiting means controls at least one of ignition timing and fuel injection quantity so as to lower the engine output. 13. The output control system according to claim 8, wherein said output limiting means retards ignition timing as compared with the fundamental ignition timing when it is determined that the exhaust control valve is operating abnormally. 14. The output control system according to claim 8, wherein said output limiting means reduces a rate of fuel injections to the engine. 15. The output control system of claim 9, wherein said output limiting means controls at least one of ignition timing and fuel injection quantity so as to lower the engine output. 16. The output control system according to claim 9, wherein said output limiting means retards ignition timing as compared with the fundamental ignition timing when it is determined that the exhaust control valve is operating abnormally. 17. The output control system according to claim 9, wherein said output limiting means reduces a rate of fuel injections to the engine. 18. The output control system of claim 11 wherein said output limiting means controls at least one of ignition timing and fuel injection quantity so as to lower the engine output. 19. The output control system according to claim 11, wherein said output limiting means retards ignition timing as compared with the fundamental ignition timing when it is determined that the exhaust control valve is operating abnormally. 20. The output control system according to claim 11, wherein said output limiting means reduces a rate of fuel injections to the engine. | CROSS-REFERENCE TO RELATED APPLICATIONS The present invention claims priority under 35 USC 119 based on Japanese patent application No. 2003-206265, filed Aug. 6, 2003. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output control system for an engine with an exhaust control device, and more particularly to an output control system for an engine equipped with an exhaust control function which controls an exhaust pulse by providing means such as a valve for changing an exhaust gas passage cross-sectional area midway in an engine exhaust air system. 2. Description of the Background Art In Japanese Patent Laid-Open No. 1-313621 or 2002-138828, there has been disclosed a technique for improving engine output by reducing resistance within an exhaust passage in a high speed area of an engine and utilizing a pulsation effect, or arranging an exhaust control valve for making the exhaust gas cross-sectional area variable within the exhaust passage in order to improve the startability for dynamically changing its throttle angle in accordance with control parameters such as a vehicle speed and an engine speed. Assuming that the above-described exhaust control valve is functioning normally, fundamental ignition timing and fundamental injection quantity of fuel in a vehicle mounted with the above-described exhaust control valve are determined with a throttle angle, engine speed, vehicle speed or the like as parameters. Thus, actual ignition timing and fuel injection quantity are determined by multiplying these fundamental ignition timing and fundamental injection quantity of fuel by various correction factors. Therefore, since when the exhaust control valve is functioning abnormally for some reason or other, the fundamental ignition timing or the fundamental injection quantity deviates from the optimum value, there is a possibility of causing problems such as deteriorated engine performance and lowered fuel economy. It is an object of the present invention to solve the above-described problems of the conventional technique, and to provide an engine exhaust control device capable of obtaining sufficient traveling performance even when the exhaust control valve is functioning abnormally. SUMMARY OF THE INVENTION In order to achieve the above-described object, according to the present invention, there is provided an output control system for an engine in which midway in an exhaust passage for guiding exhaust gas from the engine, there has been arranged an exhaust control valve for making an exhaust gas passage cross-sectional area thereof variable. The output control system includes diagnosis means for diagnosing whether or not the exhaust control valve is operating normally and output limiting means for lowering the engine output when operation of the exhaust control valve is diagnosed as abnormal. According to the above-described system, since when the exhaust control valve is functioning abnormally, control is performed so as to lower the engine output, even when the exhaust control valve is operating such that the exhaust gas cross-sectional area becomes smaller than a set point, sufficient engine performance can be secured and the lowered fuel economy can be reduced to the minimum. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing structure of a principal part of an engine output control system according to an embodiment of the present invention; FIG. 2 is a flow chart showing an operation of engine output control according to an embodiment of the present invention; FIG. 3 is a view showing relationship between fundamental ignition timing and ignition timing when the exhaust control valve is functioning abnormally; and FIG. 4 is a view showing one example of an injection thinning-out ratio table. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, with reference to the drawings, the detailed description will be made of an embodiment of the present invention. FIG. 1 is a block diagram showing structure of a principal part of an engine output control system according to the embodiment of the present invention, and within an exhaust passage 10, between an engine and a muffler, there is mounted an exhaust control valve 11. The exhaust control valve 11 variably controls the exhaust gas passage cross-sectional area by being rotated by an actuator 12 to be driven by an exhaust control valve driving unit 14. A throttle angle θex of the exhaust control valve 11 is detected by a throttle angle sensor 13, and this information is sent to the exhaust control valve driving unit 14. An engine ECU 15 includes: a fundamental ignition timing map 151 for determining fundamental ignition timing θig (θig1) on the basis of control parameters such as engine speed Ne detected by an engine speed sensor 21, a throttle angle θth obtained by detecting by a throttle angle sensor 22 and vehicle speed Vs obtained by detecting by a vehicle speed sensor 23; a fundamental fuel injection quantity map 152 for determining fundamental injection quantity Tout of fuel on the basis of the control parameters; and a target throttle angle determination unit 153 for determining a target throttle angle θex-t of the exhaust control valve 11 on the basis of the control parameters. The engine ECU 15 further includes: an exhaust control valve diagnosis unit 154 for diagnosing a throttle angle abnormality or an operation abnormality of the exhaust control valve 11; an ignition timing map 155 to be used during an abnormality for determining fundamental ignition timing θig (θig2) when the exhaust control valve 11 has been diagnosed as functioning abnormally; and an injection thinning-out table 156 to be used during an abnormality for determining a thinning-out ratio Rex for fuel injection when the exhaust control valve 11 has been diagnosed as functioning abnormally. The exhaust control valve driving unit 14 supplies driving current lex to the actuator 12 in such a manner that the target throttle angle θex-t indicated by the engine ECU 15 coincides with actual valve throttle angle θex to be detected by the throttle angle sensor 13. The exhaust control valve driving unit 14 further notifies the engine ECU 15 of the valve throttle angle θex obtained by detecting with the throttle angle sensor 13. Next, with reference to the flow chart of FIG. 2, the operation of the present embodiment will be described. In a step S1, control parameters, such as engine speed Ne, throttle angle θth and vehicle speed Vs which have been obtained by detecting with each of the related sensors, are taken in. In a step S2, exhaust control valve throttle angle θex and actuator driving current Iex, of which have been indicated by the exhaust control valve driving unit 14, are taken in. In a step S3, a difference value between the target throttle angle θex-t, which has been determined by the target throttle angle determination unit 153, and of which the exhaust control valve driving unit 14 has been indicated, and an actual valve throttle angle θex, of which has been indicated by the exhaust control valve driving unit 14, is determined by the diagnosis unit 154, and this difference value is compared with a reference difference value Δθex. In this case, if an absolute value of the difference value is equal to or exceeds the reference difference value Δθex, it will be diagnosed as a throttle angle abnormality and the sequence will proceed to a step S10. If the absolute value of the difference value is less than the reference difference value Δθex, the sequence will proceed to a step S4. In a step S4, the actual valve throttle angle θex is compared with an upper limit throttle angle θmax and a lower limit throttle angle θmin in the diagnosis unit 154. The upper limit throttle angle θmax and the lower limit throttle angle θmin have been set to the upper limit value and lower limit value of valve throttle angle θex respectively which can be taken when the exhaust control valve 11 is normally operating. Therefore, if the actual valve throttle angle θex exceeds the upper limit throttle angle θmax or falls short of the lower limit throttle angle θmin, it will be diagnosed as a throttle angle abnormality, and the sequence will proceed to the step S10. If the valve throttle angle θex is anywhere from the upper limit throttle angle θmax to the lower limit throttle angle θmin, the sequence will proceed to a step S5. In a step S5, the actuator driving current lex, of which has been notified by the exhaust control valve driving unit 14, is compared with the upper limit value Imax in the diagnosis unit 154. The upper limit value Imax has been set in advance to a value which is capable of detecting a lock current which flows when the actuator 12 is locked, or a value of a current which flows when an excessive load is applied to the actuator 12. If a driving current lex exceeds the upper limit value Imax, it will be diagnosed as an operation abnormality and the sequence will proceed to the step S10. If the driving current Iex is equal to or falls short of the upper limit value Imax, the sequence will proceed to a step S6. In a step S6, on the basis of the control parameters such as engine speed Ne, throttle angle θth and vehicle speed Vs, the fundamental ignition timing map 151 is referred to and the fundamental ignition timing θig is determined. In a step S7, on the basis of the control parameters, the fundamental fuel injection quantity map 152 is referred to and the fundamental fuel injection quantity Tout is determined. In a step S8, various correction factors such as an acceleration correction factor and a cooling water correction factor are multiplied by the fundamental fuel injection quantity Tout. In a step S9, on the basis of the fundamental ignition timing θig and the fundamental fuel injection quantity Tout, the engine is controlled. On the other hand, when diagnosed as abnormal in any of the steps S3, S4 and S5, in a step S10, on the basis of the control parameters, the ignition timing map to be used during an abnormality 155 is referred to, and the ignition timing during the abnormality is determined. FIG. 3 is a view showing relationship between ignition timing θig1 to be determined on the basis of the fundamental ignition timing map 151 and ignition timing θig2 to be determined on the basis of the ignition timing map 155 to be used during an abnormality, and illustrated with the control parameters limited to the engine speed Ne. In the present embodiment, when the exhaust control valve 11 is diagnosed as functioning abnormally, the ignition timing θig is to be retarded over the entire area of the engine speed Ne in such a manner that the engine output becomes lower than at all times of normal operation. In a step S11, as in the case of the step S7, on the basis of the control parameters, the fundamental fuel injection quantity map 152 is referred to and the fundamental fuel injection quantity Tout is determined. In a step S12, on the basis of the control parameters, an injection thinning-out table 156 to be used during abnormality is referred to and an injection thinning-out ratio Rex (%), corresponding to the percentage amount by which the normal rate of fuel injections is reduced, is determined in accordance with the control parameter value. FIG. 4 is a view showing one example of the injection thinning-out table 156 to be used during an abnormality, and illustrated with the control parameters limited to the engine speed Ne. In the present embodiment, when the exhaust control valve 11 is diagnosed as functioning abnormally, the thinning-out ratios Rex responsive to the engine speed Ne have been set stepwise in such a manner that the engine output becomes lower than at all times of normal operation. In a step S13, a message to the effect that the exhaust control valve 11 is functioning abnormally is displayed on an instrument panel or the like (not shown). In a step S14, the engine is controlled on the basis of the ignition timing θig2, the fundamental fuel injection quantity Tout and the thinning-out ratios Rex which have been determined in such a manner that the engine output becomes lower than at all times of normal operation. According to the present invention, since when the exhaust control valve is functioning abnormally, at least one of the ignition timing and the fuel injection quantity is controlled in such a manner that the engine exhaust becomes lower, even when the exhaust control valve operates in such a manner that the exhaust gas cross-sectional area reduces as compared with the set point, sufficient engine performance can be secured and lowered fuel economy can be reduced to the minimum. Although the present invention has been described herein with respect to an illustrative embodiment, the foregoing description is intended to be illustrative, and not restrictive. Those skilled in the art will realize that many modifications of the embodiment could be made which would be operable. All such modifications which are within the scope of the claims are intended to be within the scope and spirit of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to an output control system for an engine with an exhaust control device, and more particularly to an output control system for an engine equipped with an exhaust control function which controls an exhaust pulse by providing means such as a valve for changing an exhaust gas passage cross-sectional area midway in an engine exhaust air system. 2. Description of the Background Art In Japanese Patent Laid-Open No. 1-313621 or 2002-138828, there has been disclosed a technique for improving engine output by reducing resistance within an exhaust passage in a high speed area of an engine and utilizing a pulsation effect, or arranging an exhaust control valve for making the exhaust gas cross-sectional area variable within the exhaust passage in order to improve the startability for dynamically changing its throttle angle in accordance with control parameters such as a vehicle speed and an engine speed. Assuming that the above-described exhaust control valve is functioning normally, fundamental ignition timing and fundamental injection quantity of fuel in a vehicle mounted with the above-described exhaust control valve are determined with a throttle angle, engine speed, vehicle speed or the like as parameters. Thus, actual ignition timing and fuel injection quantity are determined by multiplying these fundamental ignition timing and fundamental injection quantity of fuel by various correction factors. Therefore, since when the exhaust control valve is functioning abnormally for some reason or other, the fundamental ignition timing or the fundamental injection quantity deviates from the optimum value, there is a possibility of causing problems such as deteriorated engine performance and lowered fuel economy. It is an object of the present invention to solve the above-described problems of the conventional technique, and to provide an engine exhaust control device capable of obtaining sufficient traveling performance even when the exhaust control valve is functioning abnormally. | <SOH> SUMMARY OF THE INVENTION <EOH>In order to achieve the above-described object, according to the present invention, there is provided an output control system for an engine in which midway in an exhaust passage for guiding exhaust gas from the engine, there has been arranged an exhaust control valve for making an exhaust gas passage cross-sectional area thereof variable. The output control system includes diagnosis means for diagnosing whether or not the exhaust control valve is operating normally and output limiting means for lowering the engine output when operation of the exhaust control valve is diagnosed as abnormal. According to the above-described system, since when the exhaust control valve is functioning abnormally, control is performed so as to lower the engine output, even when the exhaust control valve is operating such that the exhaust gas cross-sectional area becomes smaller than a set point, sufficient engine performance can be secured and the lowered fuel economy can be reduced to the minimum. | 20040709 | 20070501 | 20050210 | 61980.0 | 0 | EDWARDS, LOREN C | OUTPUT CONTROL SYSTEM FOR ENGINE WITH EXHAUST CONTROL FUNCTION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,888,566 | ACCEPTED | Lightweight structure particularly for an aircraft | An outer skin, for example of an aircraft body, is supported by a frame of longitudinal girders and circumferential ribs interconnecting the girders. Additionally, the outer skin is strengthened by reinforcing strips adhesively bonded to the outer skin between the ribs and girders. The reinforcing strips are made of material that is damage tolerant, for example high strength aluminum alloys and fiber composite materials are suitable for making the reinforcing strips. These reinforcing strips may extend in parallel to the stringers and/or the ribs and preferably form a lattice work. The reinforcing strips need not cross each other at right angles but should cross a crack propagation direction in the outer skin. | 1. A lightweight structure comprising an outer skin and a frame including frame elements to which said outer skin is secured, said lightweight structure further comprising reinforcing strips adhesively bonded to said outer skin, said reinforcing strips being made of a damage tolerating material, said reinforcing strips being positioned between neighboring frame elements of said frame thereby reinforcing said outer skin. 2. The lightweight structure of claim 1, wherein said reinforcing strips are positioned on said outer skin to form a lattice work. 3. The lightweight structure of claim 1, wherein said reinforcing strips are made of a composite material. 4. The lightweight structure of claim 1, wherein said reinforcing strips are made of a fiber reinforced alloy matrix, said alloy matrix comprising any one of aluminum, magnesium and titanium alloys. 5. The lightweight structure of claim 4, wherein fibers in said fiber reinforced alloy matrix are any one of carbon fibers, polyaromatic amide fibers, aluminum oxide fibers, silicon carbide fibers and basalt fibers. 6. The lightweight structure of claim 4, wherein said fiber reinforced alloy matrix is an aluminum lithium alloy. 7. The lightweight structure of claim 6, wherein said aluminum lithium alloy comprises 1% to 3% by weight of lithium. 8. The lightweight structure of claim 1, wherein said reinforcing strips are made of a laminated material comprising at least one sheet metal layer and at least one fiber composite layer. 9. The lightweight structure of claim 8, wherein said at least one sheet metal layer comprises any one sheet metal of aluminum, magnesium and titanium, and wherein said at least one fiber composite layer comprises a synthetic material matrix reinforced by fibers of any one of carbon fibers, polyaromatic amide fibers, aluminum oxide fibers, silicon carbide fibers and basalt fibers. 10. The lightweight structure of claim 1, wherein said reinforcing strips are made of a fiber reinforced composite material comprising fibers having a length of at least 5 mm. 11. The lightweight structure of claim 10, wherein said fibers have a yielding point of at least 500 megapascal (MPa). 12. The lightweight structure of claim 10, wherein said fiber reinforced composite material comprises a matrix of epoxy resin. 13. The lightweight structure of claim 1, wherein said reinforcing strips are made of a monolithic aluminum lithium alloy. 14. The lightweight structure of claim 13, wherein said monolithic aluminum lithium alloy comprises 1% to 3% by weight of lithium. 15. The lightweight structure of claim 14, wherein said outer skin is made of a monolithic sheet metal. 16. The lightweight structure of claim 15, wherein said monolithic sheet metal is any one of an aluminum alloy, a magnesium alloy and a titanium alloy. 17. The lightweight structure of claim 1, wherein said outer skin is made of a laminated material. 18. The lightweight structure of claim 17, wherein said laminated material of said outer skin has a thickness within the range of 0.5 mm to 2.0 mm. | PRIORITY CLAIM This application is based on and claims the priority under 35 U.S.C. §119 of German Patent Application 103 30 709.5, filed on Jul. 8, 2003, the entire disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION The invention relates to a lightweight structure such as an outer skin secured to a frame structure of an aircraft body. BACKGROUND INFORMATION Lightweight structures particularly as used in the aircraft technology and in spacecraft technology, frequently comprise an outer skin, the inwardly facing surface of which is reinforced by a frame structure which herein is referred to as a “two-dimensional” stiffening, compared to the entire body which is “three-dimensional”. The aircraft body is constructed of longitudinally extending stringers and circumferentially extending ribs to which the outer skin is secured, whereby the skin is reinforced by the stringers and ribs. In designing such lightweight structures special attention is paid to reducing weight. Further, lightweight structures that are used for different purposes will have different strength requirements and may need to satisfy different fatigue characteristics as well as different tolerances with regard to damages to such structures. Lightweight structures particularly used in aircraft construction must additionally satisfy special regulation requirements with regard to the tolerance characteristics that must be satisfied relative to damages that can occur during use of the aircraft. Increasing the tolerance against damages or damage tolerance of such lightweight structures can be accomplished in different ways, for example, among other things, by increasing the entire skin thickness, or by providing different skin thicknesses in different locations throughout the lightweight structure so that the skin is thicker in locations exposed to higher loads while the skin is thinner in locations exposed to lesser loads. Strengthening the skin by increasing the thickness of the skin even only locally, increases the weight more than can be tolerated. Another possibility of increasing the skin strength resides in using materials which themselves have improved tolerances against damages. Such materials are disclosed in German Patent Publication DE 102 38 460 A1, which describes metallic laminated materials or fiber composite laminates as are on the market under the Trademark GLARE®. Fiber reinforced laminated materials have the advantage of a very good tolerance against damages, even though these fiber composite materials have a relatively low density compared to monolithic metallic materials. The term “monolithic” as used herein refers to single layer materials primarily of metals, as opposed to multi-layer laminated materials. Conventional fiber composite materials have, to some extent, static strength characteristics that are not as good as such static strength characteristics of monolithic materials. Due to the lower static strength characteristics of fiber composite materials a weight reduction of the entire lightweight structure is possible only in certain areas which primarily are designed with due regard to the good damage tolerance of these materials. Furthermore, the production of fiber reinforced laminated materials is subject to a substantial effort and expense compared to monolithic sheet metals, due to the needed preparation of thin sheet metal layers for the adhesive bonding with additional prepreg films and due to the necessity of manually positioning and preparing for the following adhesive bonding step. As a result, the production costs for laminated composite materials can be significantly higher than the costs for producing monolithic sheet metals. Noticeably smaller costs are involved in the production of metallic laminated materials without a fiber reinforcement as described in the above mentioned German Patent Publication DE 102 38 460 A1. OBJECTS OF THE INVENTION In view of the foregoing it is the aim of the invention to achieve the following objects singly or in combination: to improve a lightweight structure as described above in such a way that it will have a significantly better tolerance against damages, while keeping any weight increase to an acceptable minimum; to substantially improve the crack fatigue characteristic of the lightweight structure, more specifically to reduce the crack propagation in such structures; and to strengthen the outer skin of an aircraft body, particularly in those locations where cracks tend to start and propagate. SUMMARY OF THE INVENTION The above objects have been achieved according to the invention by reinforcing strips adhesively bonded to the inwardly facing surface of the outer skin between the structural components of the frame structure or framework, such as stringers and ribs, wherein the reinforcing strips are made of a material that has a good tolerance against damages, for example by preventing or at least retarding crack propagation. The reinforcing strips may be arranged between the inwardly facing surface of the outer skin and the frame components such as stringers and ribs. Thus, the reinforcing strips may extend longitudinally parallel to the stringers or circumferentially parallel to the ribs, or both. Preferably, the reinforcing strips are arranged as a lattice work. The orientation of the reinforcing strips need not run parallel to the ribs or stringers. Rather, the reinforcing strips may preferably be oriented crosswise to the known direction of crack propagation. The above described arrangement of reinforcing strips improves the damage tolerance of such lightweight structures as an aircraft body skin in that the propagation, for example, of a fatigue crack is slowed down or even prevented in the area of the outer skin. Thus, the outer skin remains serviceable over a longer period of time, particularly where the reinforcing strips form a lattice structure. It has been found that the improvement of slowing down crack propagation or preventing crack propagation or crack formation is equally achieved for lightweight structures made of laminated materials as well as of monolithic sheet materials. A significant slow down in the crack propagation has been achieved particularly in arranging the reinforcing strips in the above mentioned lattice work that is positioned between ribs and stringers of the aircraft body frame. More specifically, it has been found that the useful life of the lightweight structure can be increased five-fold because of the slow down of the crack propagation in the outer skin. More specifically, the reinforcing strips in the form of so-called “doublers” between two neighboring stringers or two ribs slow down the crack propagation in the outer skin. It has further been found, based on comparing a single layer monolithic sheet metal skin with a multi-layer metallic laminated material both of which are equipped with reinforcing strips according to the invention and formed as a lattice structure, that the propagation of fatigue cracks is significantly reduced in the laminated material if the fatigue cracks have an initial length corresponding to the spacing between two neighboring stringers. On the other hand, the crack propagation is noticeably higher in the laminated materials than in the monolithic sheet metal skin if the fatigue crack has a length of up to twice the spacing between two stringers. The advantages of the invention are seen in a weight reduction, particularly in aircraft body skin shells which must have high damage tolerances. These tolerances are particularly significant in the shells forming part of the upper portion of an aircraft body. According to the invention using additional reinforcing strips made of a damage tolerant material, a weight reduction is possible to a significant extent because it is now possible to reduce the thickness of the sheet metal skin by about 20% compared to conventional skin thicknesses of sheet metal skins. Such a 20% reduction in sheet thickness results in a significantly reduced weight of the lightweight structure. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be clearly understood, it will now be described in connection with example embodiments thereof, with reference to the accompanying drawings, wherein: FIG. 1 shows a perspective view of a double layer skin structure strengthened by a reinforcing strip according to the invention; FIG. 2 is a view similar to that of FIG. 1, however, the skin structure is made of a single layer, preferably a monolithic sheet metal layer; FIG. 3 shows a double layer skin structure strengthened by a multi-layer reinforcing strip; FIG. 4 shows a single layer skin strengthened by a multi-layer reinforcing strip; FIG. 5 shows the crack propagation as a function of the number of load cycles applied in a test for two different types of outer skin; and FIG. 6 shows a plan view of a broken away portion of an aircraft body skin illustrating the position of the present lattice work. DETAILED DESCRIPTION OF A PREFERRED EXAMPLE EMBODIMENT AND OF THE BEST MODE OF THE INVENTION Referring first to FIG. 6 for an overview of the invention when it is used in an aircraft body, longitudinally extending stringers S1, S2 form with circumferentially extending ribs an aircraft body frame or framework FW. An outer skin OS covers the framework FW outwardly. In a preferred embodiment according to the invention a lattice work LW is adhesively bonded to the inwardly facing side of the outer skin between the ribs R1, R2 and the stringers S1, S2. As shown the lattice work LW of the preferred embodiment comprises rows R and columns C of reinforcing strips adhesively bonded to the inner surface of the outer skin OS and to each other. While the lattice work of reinforcing strips is preferred, the reinforcing strips may be arranged only as columns or only as rows. In any such embodiments the angular orientation of the columns C and/or rows R relative to the stringers and relative to the ribs will be such that the reinforcing strips cross propagation directions of cracks that may occur in the outer skin, whereby the reinforcing strips retard the propagation of such cracks. Thus, the rows and columns need not extend at right angles relative to each other. Rather, the crossing angles between the reinforcing strips may be different in different embodiments. The lattice work LW is preferably provided in each area between ribs and stringers of an aircraft body not just in one such area as shown in FIG. 6 for simplicity's sake. The improved retardation of the crack propagation that has been achieved according to the invention is described below with reference to FIG. 5. FIG. 1 shows a reinforcing strip 1 bonded by an adhesive layer 3 to an outer skin 2. The reinforcing strip 1 is preferably secured to the outer skin 2 in the form of a lattice structure as shown in FIG. 6 in which one group of reinforcing strips runs parallel to the longitudinal axis of an aircraft frame, more specifically parallel to the longitudinal stringers S1, S2 of the aircraft framework FW. Another group of reinforcing strips extends in parallel to the ribs R1, R2 of the aircraft frame FW. Thus, the second group of reinforcing trips extends circumferentially around the aircraft body. In the embodiment of FIG. 1 the outer skin 2 is a sandwich structure of two sheet metal layers 2A and 2B bonded to each other by an adhesive 2C. The reinforcing trips 1 are made of a damage tolerant material as will be explained in more detail below. Due to the adhesive bond between the reinforcing strips 1 and the outer skin 2, any crack propagation in the outer skin is retarded or slowed down significantly as will be explained below with reference to FIG. 5. As mentioned, the crossing angle between the reinforcing strips need not be a right angle, but will preferably depend on the known direction of crack propagation, so that reinforcing strips cross the crack propagation direction. FIG. 2 shows a reinforcing strip 11 bonded to an outer skin 12 by an adhesive layer 13. In this embodiment the outer skin 12 is a monolithic sheet metal member. Again, a plurality of strips 11 are arranged in a lattice structure as described above. FIG. 3 shows an embodiment in which the outer skin 22 is a laminated member including, for example a sheet metal member 22A and a fiber composite layer 22B bonded to each other by an adhesive layer 22C. The reinforcing strip 21 in FIG. 3 is a double reinforcing strip comprising, for example, two sheet metal layers or fiber composite layers 21A and 21B with two layers of reinforcing fibers 24 embedded in an adhesive bonding layer 23, for example of epoxy resin. FIG. 4 shows an embodiment in which the outer skin 32 is a single layer of a monolithic material such as a sheet metal layer or a fiber composite layer which is strengthened by a reinforcing strip 31 constructed in the same way as in FIG. 3, however the layers 31A and 31B may be fiber composite layers instead of sheet metal layers and these layers are bonded to each other and to the outer skin by adhesive layers 33, for example of epoxy resin in which the reinforcing fibers 34 are embedded. In each of FIGS. 1, 2, 3 and 4 the reinforcing strips 1, 11, 21 and 31 perform the function of increasing the damage tolerance characteristics of the entire skin structure, whereby the crack propagation in the outer skin is at least retarded or slowed down. In all embodiments shown in FIGS. 1 to 4, the reinforcing strips 1, 11, 21 and 31 preferably form a lattice work LW as shown in FIG. 1, whereby the individual strips have a width that varies between about 10 mm to about 80 mm. The strips 1 and 11 shown in FIGS. 1 and 2 are preferably made of a monolithic material, particularly an aluminum lithium alloy containing preferably about 3% by weight of lithium. Other high strength aluminum alloys are also suitable for the present purposes. Where the reinforcing strips are made of a fiber composite material, the reinforcing fibers are embedded in a matrix of an aluminum alloy or a magnesium alloy or a titanium alloy. The fibers in this embodiment are, for example, carbon fibers, polyaromatic amide fibers, aluminum oxide fibers, silicon carbide fibers, or basalt fibers. Each of these fibers reinforces the reinforcing strip structure. As shown in FIGS. 3 and 4, the strips 21 and 31 are also preferably arranged in a lattice structure but have a laminated layer structure, wherein the individual layers 31A and 31B are made sheet metal of aluminum alloys or magnesium alloys or titanium alloys with the fibers 24, 34 embedded in an epoxy resin, whereby the fibers 24, 34 may be selected from glass fibers, carbon fibers, polyaromatic amide fibers, aluminum oxide fibers, silicon carbon fibers or basalt fibers. These fibers 24 and 34 have a length of about 5 mm and have a plastic fatigue limits of at least 500 MPa. The outer skin 2, 12, 22 and 32 may be made of monolithic sheet metal layers of aluminum alloys, or titanium alloys, magnesium alloys or these outer skins may be laminated materials of two or more plies that are adhesively bonded to each other and if necessary may be individually reinforced by intermediate layers of sheet metal. Any lightweight structure may be constructed of several different layer and several lattice works LW for reinforcement. FIG. 5 shows two curves A and B. These curves represent the crack length in mm as a function of load cycles applied for testing a test sample. The sample represented by curve A had a monolithic single layer outer skin as shown, for example in FIGS. 2 and 4. The test sample represented by curve B had a laminated outer skin, for example two metal layers, one being 0.6 mm thick and the other being 0.8 mm thick. Curve A shows that at a crack length of about 400 mm the crack propagation starts rapidly to rise when the load cycles exceed 25,000, On the other hand, curve B shows that the crack propagation is retarded more effectively until about 500 mm crack length and load cycles exceeding about 37,000. Although the invention has been described with reference to specific example embodiments, it will be appreciated that it is intended to cover all modifications and equivalents within the scope of the appended claims. It should also be understood that the present disclosure includes all possible combinations of any individual features recited in any of the appended claims. | <SOH> BACKGROUND INFORMATION <EOH>Lightweight structures particularly as used in the aircraft technology and in spacecraft technology, frequently comprise an outer skin, the inwardly facing surface of which is reinforced by a frame structure which herein is referred to as a “two-dimensional” stiffening, compared to the entire body which is “three-dimensional”. The aircraft body is constructed of longitudinally extending stringers and circumferentially extending ribs to which the outer skin is secured, whereby the skin is reinforced by the stringers and ribs. In designing such lightweight structures special attention is paid to reducing weight. Further, lightweight structures that are used for different purposes will have different strength requirements and may need to satisfy different fatigue characteristics as well as different tolerances with regard to damages to such structures. Lightweight structures particularly used in aircraft construction must additionally satisfy special regulation requirements with regard to the tolerance characteristics that must be satisfied relative to damages that can occur during use of the aircraft. Increasing the tolerance against damages or damage tolerance of such lightweight structures can be accomplished in different ways, for example, among other things, by increasing the entire skin thickness, or by providing different skin thicknesses in different locations throughout the lightweight structure so that the skin is thicker in locations exposed to higher loads while the skin is thinner in locations exposed to lesser loads. Strengthening the skin by increasing the thickness of the skin even only locally, increases the weight more than can be tolerated. Another possibility of increasing the skin strength resides in using materials which themselves have improved tolerances against damages. Such materials are disclosed in German Patent Publication DE 102 38 460 A1, which describes metallic laminated materials or fiber composite laminates as are on the market under the Trademark GLARE®. Fiber reinforced laminated materials have the advantage of a very good tolerance against damages, even though these fiber composite materials have a relatively low density compared to monolithic metallic materials. The term “monolithic” as used herein refers to single layer materials primarily of metals, as opposed to multi-layer laminated materials. Conventional fiber composite materials have, to some extent, static strength characteristics that are not as good as such static strength characteristics of monolithic materials. Due to the lower static strength characteristics of fiber composite materials a weight reduction of the entire lightweight structure is possible only in certain areas which primarily are designed with due regard to the good damage tolerance of these materials. Furthermore, the production of fiber reinforced laminated materials is subject to a substantial effort and expense compared to monolithic sheet metals, due to the needed preparation of thin sheet metal layers for the adhesive bonding with additional prepreg films and due to the necessity of manually positioning and preparing for the following adhesive bonding step. As a result, the production costs for laminated composite materials can be significantly higher than the costs for producing monolithic sheet metals. Noticeably smaller costs are involved in the production of metallic laminated materials without a fiber reinforcement as described in the above mentioned German Patent Publication DE 102 38 460 A1. | <SOH> SUMMARY OF THE INVENTION <EOH>The above objects have been achieved according to the invention by reinforcing strips adhesively bonded to the inwardly facing surface of the outer skin between the structural components of the frame structure or framework, such as stringers and ribs, wherein the reinforcing strips are made of a material that has a good tolerance against damages, for example by preventing or at least retarding crack propagation. The reinforcing strips may be arranged between the inwardly facing surface of the outer skin and the frame components such as stringers and ribs. Thus, the reinforcing strips may extend longitudinally parallel to the stringers or circumferentially parallel to the ribs, or both. Preferably, the reinforcing strips are arranged as a lattice work. The orientation of the reinforcing strips need not run parallel to the ribs or stringers. Rather, the reinforcing strips may preferably be oriented crosswise to the known direction of crack propagation. The above described arrangement of reinforcing strips improves the damage tolerance of such lightweight structures as an aircraft body skin in that the propagation, for example, of a fatigue crack is slowed down or even prevented in the area of the outer skin. Thus, the outer skin remains serviceable over a longer period of time, particularly where the reinforcing strips form a lattice structure. It has been found that the improvement of slowing down crack propagation or preventing crack propagation or crack formation is equally achieved for lightweight structures made of laminated materials as well as of monolithic sheet materials. A significant slow down in the crack propagation has been achieved particularly in arranging the reinforcing strips in the above mentioned lattice work that is positioned between ribs and stringers of the aircraft body frame. More specifically, it has been found that the useful life of the lightweight structure can be increased five-fold because of the slow down of the crack propagation in the outer skin. More specifically, the reinforcing strips in the form of so-called “doublers” between two neighboring stringers or two ribs slow down the crack propagation in the outer skin. It has further been found, based on comparing a single layer monolithic sheet metal skin with a multi-layer metallic laminated material both of which are equipped with reinforcing strips according to the invention and formed as a lattice structure, that the propagation of fatigue cracks is significantly reduced in the laminated material if the fatigue cracks have an initial length corresponding to the spacing between two neighboring stringers. On the other hand, the crack propagation is noticeably higher in the laminated materials than in the monolithic sheet metal skin if the fatigue crack has a length of up to twice the spacing between two stringers. The advantages of the invention are seen in a weight reduction, particularly in aircraft body skin shells which must have high damage tolerances. These tolerances are particularly significant in the shells forming part of the upper portion of an aircraft body. According to the invention using additional reinforcing strips made of a damage tolerant material, a weight reduction is possible to a significant extent because it is now possible to reduce the thickness of the sheet metal skin by about 20% compared to conventional skin thicknesses of sheet metal skins. Such a 20% reduction in sheet thickness results in a significantly reduced weight of the lightweight structure. | 20040708 | 20071023 | 20050526 | 88595.0 | 0 | THOMPSON, CAMIE S | LIGHTWEIGHT STRUCTURE PARTICULARLY FOR AN AIRCRAFT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,888,667 | ACCEPTED | Charge pump circuit operating responsive to a mode | Disclosed is a charge pump circuit that operates responsive to a test or general operation mode. The charge pump circuit includes at least one charge pump part. A voltage level sensing block generates a level sensing signal by sensing an output voltage. An oscillator generates complementary pulse signals responsive to the level sensing signal. And a selecting circuit block generates a selected voltage that is one of a high voltage and a supply voltage to the at least one charge pump part, the high voltage having a level higher than the supply voltage. | 1. A charge pump circuit comprising: a charge pump block including at least one charge pump part; and a voltage supply circuit to supply a pre-charge voltage to the at least one charge pump part responsive to a mode. 2. The charge pump circuit of claim 1 where the pre-charge voltage is a supply voltage in a general mode. 3. The charge pump circuit of claim 1 where the pre-charge voltage is a voltage higher than the supply voltage in a test mode. 4. The charge pump circuit of claim 1 where the voltage supply circuit comprises: a detector circuit to generate a detect signal responsive to a high voltage; and a selector circuit to supply the pre-charge voltage responsive to the detect signal. 5. The charge pump circuit of claim 1 where the voltage supply circuit comprises: a voltage level sensing block to generate a level sensing signal responsive to a pump enable signal; and an oscillator to generate complementary pulse signals responsive to the level sensing signal. 6. The charge pump circuit of claim 1 where the voltage supply circuit comprises a charge trapping part to generate an output voltage. 7. A charge pump circuit comprising: at least one charge pump part; a voltage level sensing block to generate a level sensing signal by sensing an output voltage; an oscillator to generate complementary pulse signals responsive to the level sensing signal; and a selecting circuit block to generate a selected voltage that is one of a high voltage and a supply voltage to the at least one charge pump part, the high voltage having a level higher than the supply voltage. 8. The charge pump circuit of claim 7 comprising: a charge supply part to precharge the at least one charge pump part with the selected voltage; and a charge trapping part to store charges provided by the charge supply part. 9. The charge pump circuit of claim 8 where the at least one charge pump part pumps a charge to another charge pump part. 10. The charge pump circuit of claim 8 where the charge supply part comprises a high-voltage PMOS transistor. 11. The charge pump circuit of claim 7 where the at least one charge pump part includes a high-voltage NMOS transistor. 12. The charge pump circuit of claim 7 where the selecting circuit block compares the supply voltage with the high voltage; and where the selecting circuit selects the high voltage if a level of the high voltage is higher than a level of the power voltage. 13. A charge pump circuit comprising: a charge pump block including at least one charge pump part; a voltage level sensing block to sense a level of an output voltage and generate a level sensing signal responsive thereto; an oscillator to generate a pulse signal responsive to the level sensing signal; a detector to generate a detection signal responsive to a high voltage; and a selector to provide one of the high voltage and the power voltage responsive to the detection signal to the charge pump block. 14. The charge pump circuit of claim 13 where the charge pump block comprises: a charge supply part to precharge the at least one charge pump part; and a charge trapping part to store charges pumped from the at least one charge pump part. 15. The charge pump circuit of claim 14 where the at least one charge pump part pumps charge to another serially connected charge pump part. 16. The charge pump circuit of claim 14 where the charge supply part includes a high-voltage PMOS transistor. 17. The charge pump circuit of claim 14 where the charge pump block includes a high-voltage NMOS transistor. 18. The charge pump circuit of claim 13 where the selector compares the high voltage to the power voltage. | BACKGROUND OF THE INVENTION 1. Priority Info This application claims priority from Korean Patent Application Number 2003-46799, filed Jul. 10, 2003, that we incorporate here by reference. 2. Field of the Invention The present invention relates to high-voltage generators and, more specifically, to charge pump circuits operating responsive to a mode that enables selection of a power voltage or an external high voltage. 3. Discussion of the Related Art FIG. 1 is a block diagram of a conventional charge pump circuit. As shown in FIG. 1, the conventional charge pump circuit comprises a voltage level sensing block 20, an oscillator 30, and a charge pump block 10. The voltage level sensing block 20 senses a level of the output voltage Vout. The oscillator 30 generates pulse signals PUL, /PUL responsive to a signal DET output from the block 20. The charge pump block 10 performs a pumping operation. The voltage level sensing block 20, as shown in FIG. 2, comprises a differential amplifier. The voltage level sensing block 20 operates responsive to a pumping enable signal enPUMP and compares output voltage Vout with reference voltage VREF. The voltage level sensing block 20 generates a level sensing signal DET. As shown in FIG. 3, the oscillator 30 comprises one NOR gate G1 and four invertors INV1, INV2, INV3 and INV4. And the oscillator 30 responds the level sensing signal DET to generate the complimentary pulse signals PUL, /PUL. The charge pump block 10 comprises a charge supply part 11 and a plurality of charge pump parts 12-15. The charge supply part 11 receives an external voltage VCC and provides supply charges to a first charge pump part PSI. The charge pump parts PS1, PS2, PS3, . . . , PSn are serially connected. The charge pump parts 12-15 generate an output voltage Vout by pumping charges supplied from the charge supply part 11. An odd number of pump parts 11-15 operates responsive to the pulse signal PUL, while an even number of them operate responsive to the inverted pulse signal/PUL. The conventional charge pump shown in FIG. 1 operates as follows. When the pumping enable signal enPUMP is in a predetermined logic level, e.g., becomes high, the voltage level sensing block 20 senses the level of the output voltage Vout by comparing output voltage Vout to a reference voltage VREF. If the reference voltage VREF is larger than the output voltage Vout, the voltage level sensing block 20 generates the level sensing signal DET having a predetermined state, e.g., high. On the other hand, if the output voltage Vout is larger than reference voltage VREF, the voltage level sensing block 20 generates the level sensing signal DET having e.g., a low state. The oscillator 30 provides the pulse signals PUL and/PUL to the charge pump parts PS1, PS2, PS3, . . . , PSn responsive to the level sensing signal DET. That is, if the level sensing signal (DET) is enabled, all charge pump parts PS1, PS2, PS3, . . . , PSn increase the level of the output voltage Vout. If the level sensing signal (DET) is disable, all charge pump parts PS1, PS2, PS3, . . . , PSn decrease the level of the output voltage Vout. The conventional charge pump circuit pre-charges the output voltage Vout corresponding to the external voltage VCC at each node of the charge supply part 11 and the charge pump parts 12-15. Accordingly, the time to precharge increases in the output voltage Vout. This additional time is undesired, particularly where testing integrated chips that require high voltages quickly. A need remains for an improved charge pump circuit. SUMMARY A feature of the invention is to address disadvantages associated with prior charge pumps. Another feature of the invention is to provide a charge pump that operates both in a test and in a general operation mode. A charge pump circuit includes at least one charge pump part. A voltage level sensing block generates a level sensing signal by sensing an output voltage. An oscillator 30 generates complementary pulse signals responsive to the level sensing signal. And a selecting circuit block generates a selected voltage that is one of a high voltage and a supply voltage to the at least one charge pump part, the high voltage having a level higher than the supply voltage. BRIEF DESCRIPTION The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings: FIG. 1 is a block diagram of a conventional charge pump circuit. FIG. 2 is a circuit diagram of the sensing level sensing block 20 shown in FIG. 1. FIG. 3 is a circuit diagram of the oscillator 30 shown in FIG. 1. FIG. 4 is a block diagram of an embodiment of a charge pump circuit according to the present invention. FIG. 5 is a circuit diagram of an embodiment of a charge pump part shown in FIG. 4. FIG. 6 is a circuit diagram of an embodiment of the selector shown in FIG. 4. FIG. 7 is a circuit diagram of an embodiment of the detector shown in FIG. 4. FIG. 8 is a graph of the output voltage for the charge pump circuit of the present invention. DETAILED DESCRIPTION Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The present invention is, however, not limited to the embodiments illustrated here. Rather, the embodiments are introduced to provide easy and complete understanding of the scope and spirit of the present invention. FIG. 4 is a block diagram of an embodiment of the charge pump circuit according to the present invention. Referring to FIG. 4, the charge pump circuit comprises a charge pump block 100, a selecting circuit block 200, an oscillator 300, and a voltage level sensing block 400. The pump block 100 comprises a charge supply part 110, a plurality of charge pump parts 120, 130, 140, and 150 and a charge trapping part 160, all serially connected. The charge supply part 110 provides a charge corresponding to voltage Vsel provided, in turn, by the selecting circuit block 200 to a first charge pump part 120. The charge pump parts 120, 130, 140 and 150 pre-charge a charge corresponding to the selected voltage Vsel and pumps a charge to a next serially connected charge supply part. The charge trapping part 160 traps the pumped charge through each charge pump part 120, 130, 140 and 150 to generate an output voltage Vout. FIG. 5 is a block diagram of the charge pump block 100 shown in FIG. 4. Referring to FIG. 5, the sensing level part 400 senses level of output voltage Vout when a pumping enable signal enPUMP is enabled. In other words, if the output voltage Vout is smaller than the reference voltage Vref, the level sensing signal DET is enabled. If the output voltage Vout is larger than the reference voltage Vref, on the other hand, the level sensing signal DET is disabled. The oscillator 300 generates complementary pulse signals PUL and/PUL responsive to the level sensing signal DET. If the level sensing signal DE) is enabled, all charge pump parts 120, 130, 140 and 150 increase the output voltage Vout. If the level sensing signal DET is disabled, the charge pump parts 120, 130, 140 and 150 do not operate. Referring to FIG. 4, the charge pump circuit according to the present invention comprises a selecting circuit block 200. The selecting circuit block 200 includes a selector 210 and a detector 220. In the specification power supply voltage VCC refers to the power voltage operating in general operation mode. The voltage VPP refers to a high voltage provided externally during a test operation mode. The high voltage VPP may be applied externally in the test operation mode as well as during the general operation mode. The selecting circuit block 200 comprises the selector 210 and the detector 220. The selector 210 selects between the power voltage VCC and the high voltage VPP. The detector 220 detects the level of the high voltage VPP to generate detection signal VDET. The detector 220 enables the detection signal VDET when the high voltage VPP is higher than the power voltage VCC. The selector 210 switches between the power voltage VCC to the high voltage VPP responsive to the detection signal VDET. Put differently, the signal VSEL is VCC in the general operation mode and VPP in the test operation mode allowing for a high voltage within a short time. The selector 210 and the detector 220 are more fully described referring to FIGS. 6 and 7. FIG. 5 is a circuit diagram of the charge pump block 100 shown in FIG. 4. Referring to FIG. 5, the charge pump block 100 operates as follows. The charge pump block 100 comprises the charge supply part 110, charge pump parts 120, 130, 140 and 150, and the charge trapping part 160. The charge supply part 110 comprises high-voltage PMOS transistor P110 available simultaneously in general and test operation modes. The high-voltage PMOS transistor P110 is connected between node 1 and node 2. Source and bulk terminals of the high-voltage PMOS transistor P110 are connected to the node 1. A drain terminal is connected to the node 2. A gate is connected to a ground GND terminal. The charge supply part 110 is available for a charge supply device and supplies charges to a first charge pump part 120 located in next part. For example, if VSEL is VPP in the general operation mode, charges corresponding to the power voltage VCC are pre-charged at node 2. In addition, if VSEL is VPP in test operation mode, charges corresponding to the high voltage VCC are pre-charged at node 2. Each charge pump part 120, 130, 140 and 150 comprises one PMOS transistor, e.g., transistor P120, one capacitor, e.g., capacitor C120, and one high-voltage NMOS transistor, e.g., transistor N120. The high-voltage NMOS transistor, e.g., transistor N120, operates both in the general operation mode as well as the test operation mode. An odd number (or even number) of the charge pump parts operates responsive to the pulse signal PUL, while an even number (or odd number) of the charge parts operates responsive to the inverted pulse signal/PUL. In the specification, pump parts except for the first charge pump part 120 is omitted for clarity. We describe only charge part 120 for simplicity. A person of reasonable skill should realize that other charge parts operate and include similar elements. A source terminal of the PMOS transistor P120 is connected to the node 2. The source terminal of the PMOS transistor P120 is used as a charge transfer device. A drain terminal and a gate terminal are connected to the node 3. A bulk terminal is in a floating state. A capacitor C 120 is used as a charge pumping device and is connected between the node 3 and the node 8. The pulse signal PUL or/PUL is applied to the capacitor C120. The drain of the NMOS transistor N120 is connected to the node 1. A source terminal is connected to the node 3, and the bulk terminal is connected to ground GND. The gate and drain terminals of high-voltage NMOS transistor N120 are used as a pre-charge device. The high-voltage NMOS transistor N120 pre-charges charges corresponding to the selecting voltage VSEL at the node 3. For example, if the threshold voltage of the high-voltage NMOS transistor N120 is VTH, charges corresponding to VSEL-VTH are pre-charged. In other words, charges corresponding to VCC-VTH are pre-charged in the general operation mode, and charges corresponding to VPP-VTH are pre-charged in the test mode. The charge trapping part 160 comprises one PMOS transistor P160 and one capacitor. The PMOS transistor P160 is used as charge transfer device, and the capacitor is used as charge trapping device. The charge trapping part 160 generates the output voltage Vout. FIG. 6 is a circuit diagram of the selector 210 shown in FIG. 4. Referring to FIG. 6, the selector 210 uses a level shifter to control the high voltage VPP. The selector 210 comprises high-voltage NMOS transistors N211 to N218, high-voltage PMOS transistors P211 to P218 and P210_I where i=1 to 4, and two serially connected inverters. The level shifter selects between the power voltage VCC and the high voltage VPP. For instance, the high-voltage NMOS transistors N216 and N217 turn on in the test operation mode where the detection signal VDET is enables. The high-voltage PMOS transistors P210_3 and P210_4 turn on. As a result, VSEL is equal to VPP. However, since the high-voltage NMOS transistors N212 and N213 are turned off, the high-voltage PMOS transistors P210_1 and P210_2 are also turned off. Accordingly, VSEL is not equal to VCC. To the contrary, VSEL is equal to VCC in general operation mode where the detection signal VDET is disabled. FIG. 7 is a circuit diagram of the detector 220 shown in FIG. 4. Referring to FIG. 7, the detector 220 comprises high-voltage PMOS transistors P221 and P222, high-voltage NMOS transistors N221-N224, a high-voltage inverter HV INV and a low-voltage inverter LV INV. The detector 220 can be used in the general as well as test operation mode requiring high voltage. For example, if external high-voltage VPP is lower than the power voltage VCC, a node A has a voltage that is VCC-VTH. Accordingly, the PMOS transistor P221 is off. At this time, node B voltage is ground GND. In another approach, if external high-voltage VPP is higher than the power voltage VCC, node A voltage is VPP-VTH. As VPP increases, node B has high enough voltage to inverse the output of the high-voltage inverter HV INV. This output generates a high detection signal VDET through passing the low-voltage inverter LV INV. FIG. 8 is a graph of the output voltage Vout depending on whether the charge pump circuit uses the power voltage VCC or external high voltage VPP. Settling time is a time required for the pumping operation to obtain a wanted output voltage Vout. Referring to FIG. 8, if the selected voltage VSEL is under the condition that the power voltage VCC is equal to 1.8V, and the external voltage VPP is equal to 8V, it is known that four times settling times (STp) is required to obtain an output voltage Vout of 10V. That is, when external high voltage VPP is supplied with the power voltage VCC, a wanted output voltage Vout can be obtained within more short time. As previously mentioned, the charge pump circuit can obtain a wanted output voltage Vout within a short time by further including selective means capable of applying high voltage rather than the power voltage VCC. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Priority Info This application claims priority from Korean Patent Application Number 2003-46799, filed Jul. 10, 2003, that we incorporate here by reference. 2. Field of the Invention The present invention relates to high-voltage generators and, more specifically, to charge pump circuits operating responsive to a mode that enables selection of a power voltage or an external high voltage. 3. Discussion of the Related Art FIG. 1 is a block diagram of a conventional charge pump circuit. As shown in FIG. 1 , the conventional charge pump circuit comprises a voltage level sensing block 20 , an oscillator 30 , and a charge pump block 10 . The voltage level sensing block 20 senses a level of the output voltage Vout. The oscillator 30 generates pulse signals PUL, /PUL responsive to a signal DET output from the block 20 . The charge pump block 10 performs a pumping operation. The voltage level sensing block 20 , as shown in FIG. 2 , comprises a differential amplifier. The voltage level sensing block 20 operates responsive to a pumping enable signal enPUMP and compares output voltage Vout with reference voltage VREF. The voltage level sensing block 20 generates a level sensing signal DET. As shown in FIG. 3 , the oscillator 30 comprises one NOR gate G 1 and four invertors INV 1 , INV 2 , INV 3 and INV 4 . And the oscillator 30 responds the level sensing signal DET to generate the complimentary pulse signals PUL, /PUL. The charge pump block 10 comprises a charge supply part 11 and a plurality of charge pump parts 12 - 15 . The charge supply part 11 receives an external voltage VCC and provides supply charges to a first charge pump part PSI. The charge pump parts PS 1 , PS 2 , PS 3 , . . . , PSn are serially connected. The charge pump parts 12 - 15 generate an output voltage Vout by pumping charges supplied from the charge supply part 11 . An odd number of pump parts 11 - 15 operates responsive to the pulse signal PUL, while an even number of them operate responsive to the inverted pulse signal/PUL. The conventional charge pump shown in FIG. 1 operates as follows. When the pumping enable signal enPUMP is in a predetermined logic level, e.g., becomes high, the voltage level sensing block 20 senses the level of the output voltage Vout by comparing output voltage Vout to a reference voltage VREF. If the reference voltage VREF is larger than the output voltage Vout, the voltage level sensing block 20 generates the level sensing signal DET having a predetermined state, e.g., high. On the other hand, if the output voltage Vout is larger than reference voltage VREF, the voltage level sensing block 20 generates the level sensing signal DET having e.g., a low state. The oscillator 30 provides the pulse signals PUL and/PUL to the charge pump parts PS 1 , PS 2 , PS 3 , . . . , PSn responsive to the level sensing signal DET. That is, if the level sensing signal (DET) is enabled, all charge pump parts PS 1 , PS 2 , PS 3 , . . . , PSn increase the level of the output voltage Vout. If the level sensing signal (DET) is disable, all charge pump parts PS 1 , PS 2 , PS 3 , . . . , PSn decrease the level of the output voltage Vout. The conventional charge pump circuit pre-charges the output voltage Vout corresponding to the external voltage VCC at each node of the charge supply part 11 and the charge pump parts 12 - 15 . Accordingly, the time to precharge increases in the output voltage Vout. This additional time is undesired, particularly where testing integrated chips that require high voltages quickly. A need remains for an improved charge pump circuit. | <SOH> SUMMARY <EOH>A feature of the invention is to address disadvantages associated with prior charge pumps. Another feature of the invention is to provide a charge pump that operates both in a test and in a general operation mode. A charge pump circuit includes at least one charge pump part. A voltage level sensing block generates a level sensing signal by sensing an output voltage. An oscillator 30 generates complementary pulse signals responsive to the level sensing signal. And a selecting circuit block generates a selected voltage that is one of a high voltage and a supply voltage to the at least one charge pump part, the high voltage having a level higher than the supply voltage. | 20040708 | 20080923 | 20050113 | 61909.0 | 0 | HILTUNEN, THOMAS J | CHARGE PUMP CIRCUIT OPERATING RESPONSIVE TO A MODE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,888,784 | ACCEPTED | Method and apparatus for securely displaying and communicating trusted and untrusted internet content | A method and apparatus for securely displaying and communicating trusted and untrusted internet content via a web browser is described. In a preferred embodiment, the invention is an electronic marketplace system in which auction-related content is displayed in one window of a customer's web browser while item-related content is displayed in a second window of the customer's web browser, such that the auction-related content and the item-related content are substantially prevented from substantially interacting. The invention further provides a method and apparatus for communicating predetermined information between multiple documents opened in multiple web browser windows, where the documents are served from multiple domains. | 1. One or more computer readable media having stored thereon a plurality of instructions that, when executed by one or more processors of a computing device, causes the one or more processors to perform the steps comprising: receiving a first set of content from a first source; storing the first set of content on a first domain; receiving a second set of content from a second source; and storing the second set of content on a second domain different than the first domain; such that if the first and second sets of content were transmitted to a web browser supporting a cross-frame security feature and displayed in two separate browser views, the web browser would prevent the first and second sets of content from substantially interacting. 2. One or more computer readable media as in claim 1, wherein the first set of content is trusted content, and wherein the second set of content is untrusted content. 3. One or more computer readable media as in claim 2, wherein the trusted content lists an item or service offered in an electronic marketplace. 4. One or more computer readable media as in claim 2, wherein the trusted content is content provided by an electronic marketplace service. 5. One or more computer readable media as in claim 2, wherein the trusted content is content provided in a format other than HTML by a seller participating in an electronic marketplace service. 6. One or more computer readable media as in claim 2, wherein the untrusted content is provided in HTML format by a seller participating in an electronic marketplace service. 7. One or more computer readable media as in claim 6, wherein the untrusted content is a description of an item or service offered via an electronic marketplace. 8. One or more computer readable media as in claim 1, wherein said plurality of instructions further causes the one or more processors to perform the steps of: transmitting the first and second sets of content to a web browser. 9. One or more computer readable media as in claim 8, wherein said plurality of instructions further causes the one or more processors to perform the step of: instructing the web browser to display the first set of content in a first browser view and the second set of content in a second browser view. 10. One or more computer readable media as in claim 8, wherein the web browser supports a cross-frame security feature. 11. One or more computer readable media having stored thereon a plurality of instructions that, when executed by one or more processors of a computing device, causes the one or more processors to perform the steps comprising: receiving, from a first browser view of a web browser, a request to view a web page including a first set of content and a second set of content; transmitting to the web browser, from a first domain, a first document containing the first set of content; transmitting, from a second domain different than the first domain, a second document containing the second set of content; and instructing the web browser to display the first document in a first browser view and the second document in a second browser view; such that the web browser prevents the first and second sets of content from substantially interacting. 12. One or more computer readable media as in claim 11, wherein the web browser supports a cross-frame security feature. 13. One or more computer readable media as in claim 11, wherein the first set of content is trusted content and the second set of content is untrusted content. 14. One or more computer readable media as in claim 11, wherein the web page lists an item or service offered in an electronic marketplace. 15. One or more computer readable media as in claim 11, wherein the trusted content is content provided by an electronic marketplace service. 16. One or more computer readable media as in claim 11, wherein the trusted content is content provided in a format other than HTML by a seller participating in an electronic marketplace service. 17. One or more computer readable media as in claim 11, wherein the untrusted content is provided in HTML format by a seller participating in an electronic marketplace service. 18. One or more computer readable media as in claim 17, wherein the untrusted content is a description of an item or service offered in an electronic marketplace. 19. One or more computer readable media having stored thereon a plurality of instructions that, when executed by one or more processors of a computing device, causes the one or more processors to perform the steps comprising: receiving, in a first browser view of a web browser, a first document from a first domain; receiving, in a second browser view, a second document from a second domain different than the first domain, wherein the second document includes predetermined information that is to be passed to the first document; creating a first communication that includes the information from the second document that is to be passed to the first document; and sending the first communication to the first domain via a third browser view. 20. One or more computer readable media as in claim 19, wherein the web browser supports a cross-frame security feature. 21. One or more computer readable media as in claim 19, wherein the first communication comprises a URL. 22. One or more computer readable media as in claim 21, wherein the first communication further comprises one of a query string and a form data block. 23. One or more computer readable media as in claim 21, wherein the URL is the address of a third document on the first domain. 24. One or more computer readable media as in claim 19, wherein said plurality of instructions further causes the one or more processors to perform the step of: receiving, in one of the first and third browser views, data from the first domain that is responsive to the information included in the first communication. 25. One or more computer readable media as in claim 24, wherein the data from the first domain is a document to be rendered in the third browser view. 26. One or more computer readable media as in claim 24, wherein the data from the first domain is a dynamic HTML update to the first browser view. 27. One or more computer readable media as in claim 24, wherein said plurality of instructions further causes the one or more processors to perform the step of: adjusting the size of one of the first and second browser views based on the responsive data from the first domain. 28. One or more computer readable media as in claim 24, wherein said plurality of instructions further causes the one or more processors to perform the step of: creating a second communication including information to be passed to the second document. 29. One or more computer readable media as in claim 28, wherein said plurality of instructions further causes the one or more processors to perform the step of: sending the second communication to the second domain. 30. One or more computer readable media as in claim 29, wherein said plurality of instructions further causes the one or more processors to perform the step of: receiving, via one of the second browser view and a fourth browser view, responsive data from the second domain that is responsive to the information included in the second communication. 31. One or more computer readable media having stored thereon a plurality of instructions that, when executed by one or more processors of a computing device, causes the one or more processors to perform the steps comprising: transmitting a first document from a first domain to a first browser view in a web browser wherein the first document includes an instruction to the web browser to obtain, via a second browser view, a second document from a second domain different from the first domain; and receiving, from a third browser view of the web browser, a first communication including information derived from the second document. 32. One or more computer readable media as in claim 31, wherein the web browser supports a cross-frame security feature, 33. One or more computer readable media as in claim 31, wherein the first communication comprises a URL. 34. One or more computer readable media as in claim 33, wherein the URL is the address of a third document on the first domain. 35. One or more computer readable media as in claim 31, wherein the first communication further comprises one of a query string and a form data block. 36. One or more computer readable media as in claim 31, wherein said plurality of instructions further causes the one or more processors to perform the step of: parsing the first communication to extract the information derived from the second document. 37. One or more computer readable media as in claim 36, wherein said plurality of instructions further causes the one or more processors to perform the step of: based on the information extracted from the first communication, transmitting additional content from the first domain to the web browser. 38. One or more computer readable media as in claim 37, wherein said additional content dynamically updates the content of the first document in the first browser view. 39. One or more computer readable media as in claim 37, wherein said additional content is a third document capable of exchanging data with the first document in the first browser view. 40. One or more computer readable media as in claim 37, wherein said additional content instructs the web browser (a) to create a second communication containing predetermined information from the first domain and (b) to send the second communication to the second domain. 41. One or more computer readable media as in claim 40, wherein said plurality of instructions further causes the one or more processors to perform the steps of: receiving, from the web browser, a third communication having additional information derived from the second domain. 42. One or more computer readable media as in claim 41, wherein said plurality of instructions further causes the one or more processors to perform the steps of: parsing the third communication to extract the additional information derived from the second domain. 43. A method for securely communicating internet content, comprising the steps of: receiving a first set of content from a first source; storing the first set of content on a first domain; receiving a second set of content from a second source; and storing the second set of content on a second domain different than the first domain; such that if the first and second sets of content were transmitted to a web browser supporting a cross-frame security feature and displayed in two separate browser views, the web browser would prevent the first and second sets of content from substantially interacting. 44. A method for securely communicating internet content, comprising the steps of: receiving, from a first browser view of a web browser, a request to view a web page including a first set of content and a second set of content; transmitting to the web browser, from a first domain, a first document containing the first set of content; transmitting, from a second domain different than the first domain, a second document containing the second set of content; and instructing the web browser to display the first document in a first browser view and the second document in a second browser view; such that the web browser prevents the first and second sets of content from substantially interacting. 45. A method for securely communicating internet content, comprising the steps of: receiving, in a first browser view of a web browser, a first document from a first domain; receiving, in a second browser view, a second document from a second domain different than the first domain, wherein the second document includes predetermined information that is to be passed to the first document; creating a first communication that includes the information from the second document that is to be passed to the first document; and sending the first communication to the first domain via a third browser view. 46. A method for securely communicating internet content, comprising the steps of: transmitting a first document from a first domain to a first browser view in a web browser wherein the first document includes an instruction to the web browser to obtain, via a second browser view, a second document from a second domain different from the first domain; and receiving, from a third browser view of the web browser, a first communication including information derived from the second document. 47. A system for securely communicating internet content, comprising: a means for receiving a first set of content from a first source; a means for storing the first set of content on a first domain; a means for receiving a second set of content from a second source; and a means for storing the second set of content on a second domain different than the first domain; such that if the first and second sets of content were transmitted to a web browser supporting a cross-frame security feature and displayed in two separate browser views, the web browser would prevent the first and second sets of content from substantially interacting. 48. A system for securely communicating internet content, comprising: a means for receiving, from a first browser view of a web browser, a request to view a web page including a first set of content and a second set of content; a means for transmitting to the web browser, from a first domain, a first document containing the first set of content; a means for transmitting, from a second domain different than the first domain, a second document containing the second set of content; and a means for instructing the web browser to display the first document in a first browser view and the second document in a second browser view; such that the web browser prevents the first and second sets of content from substantially interacting. 49. A system for securely communicating internet content, comprising: a means for receiving, in a first browser view of a web browser, a first document from a first domain; a means for receiving, in a second browser view, a second document from a second domain different than the first domain, wherein the second document includes predetermined information that is to be passed to the first document; a means for creating a first communication that includes the information from the second document that is to be passed to the first document; and a means for sending the first communication to the first domain via a third browser view. 50. A system for securely communicating internet content, comprising: a means for transmitting a first document from a first domain to a first browser view in a web browser wherein the first document includes an instruction to the web browser to obtain, via a second browser view, a second document from a second domain different from the first domain; and a means for receiving, from a third browser view of the web browser, a first communication including information derived from the second document. | FIELD OF THE INVENTION This invention relates to securely displaying and communicating trusted and untrusted internet content via a web browser. The present invention further relates to communicating predetermined information between a multiple documents opened in multiple web browser windows, where the documents are served from multiple domains. BACKGROUND OF THE INVENTION Electronic marketplaces, such as the person-to-person trading system pioneered by eBay, Inc., have become a well-known way to buy and sell goods and services via the Internet. Typical electronic marketplace systems allow sellers to enter a description of the item or service they wish to offer through an online auction. This item description may be in text or HTML format and is then stored on the electronic marketplace system. When a prospective buyer wishes to view the item (or service) that is being offered, he directs his web browser to download and display the appropriate item listing web page from the electronic marketplace system. The item listing web page typically is an HTML document that includes not only the seller's item description but also other content provided by the electronic marketplace service. FIG. 1 shows an example of such a web page. In addition to the item description 114, the item listing document may include, e.g., an item title 100 (“Sample Item for Sale”), a minimum starting bid 102, the time remaining before the auction ends 104, the auction start time 106, the bid history 108, the item location 110, the shipping summary 112, detailed instructions concerning shipping and handling 116, payment methods accepted 118, legal disclaimers 120, an item number 122, and seller information 124 such as the seller's feedback rating. As noted above, the item listing web page is normally an HTML document that includes not only content provided by the electronic marketplace service, but also the seller-provided item description, which may itself contain executable code, e.g., HTML code. For example, the item description 114 on FIG. 1 (“*** Sample HTML item description ***”) was produced by the following HTML code: <br> * * * <br> <b>Sample HTML item description</b> <br> * * * Thus, the web browser on the potential buyer's computer “renders” both the service-provided HTML content and the seller-provided HTML content. There is, however, an undesirable byproduct of permitting sellers to describe their items or services using embedded code. For example, a malicious seller might include HTML code that makes use of malicious HTML tags or scripts to alter the content provided by the auction service. For example, a malicious seller might attempt to replace a particular logo with a different image or try to divert private information that a potential buyer might provide to the auction service (e.g., cookie information). These risks associated with embedded code have been widely recognized among web site providers. For example, the Department of Energy's Computer Incident Advisory Capability has reported that “[m]ost web browsers have the capability to interpret scripts embedded in web pages downloaded from a web server. Such scripts may be written in a variety of scripting languages and are run by the client's browser . . . . In addition to scripting tags, other HTML tags . . . have the potential to be abused by an attacker . . . to alter the appearance of the page, insert unwanted or offensive images or sounds, or otherwise interfere with the intended appearance and behaviour of the page.” CIAC Information Bulletin K-021. An approach that is conventionally used to address the risks associated with embedded content is to filter out potentially malicious code from within the embedded content. For example, a filter program might search the embedded code for <script> </script> HTML tags and delete any code that lies between the tags. A difficulty with this approach, however, is that a filter program may still fail to eliminate all of the potentially dangerous characters in the embedded code. Alternatively, the filter program may filter out too much material. In the above example, the filter program would prevent any and all scripts whatsoever from executing, including scripts that may be desirable or beneficial. Thus, a long-felt need exists for a way to display both trusted content (e.g., the auction-service HTML content) and untrusted content (e.g., the seller-provided HTML content), while at the same time preventing the untrusted content from modifying or manipulating the trusted content. SUMMARY OF THE INVENTION The present invention solves this problem of embedded code by separating trusted and untrusted content on a web page served from a web server system to a web browser on a client computer. In accordance with the invention, the trusted and untrusted content is stored on separate network domains in the web server system. When the user requests the web page via a web browser, the user's web browser is instructed to display the trusted content in one browser window, and the untrusted content in a second browser view. As long as the web browser supports a cross-frame security feature, the web browser then prevents the trusted and untrusted content from substantially interacting. Thus, the present invention provides a method for separating content on a web server system comprising the steps of receiving a first set of content from a first source; storing the first set of content on a first domain of the web server system; receiving a second set of content from a second source; and storing the second set of content on a second domain of the web server system; such that if the first and second sets of content were transmitted to a web browser supporting a cross-frame security feature and displayed in two separate browser views, the web browser would prevent the first and second sets of content from substantially interacting. The present invention further provides a method for securely communicating content to a user's web browser from a web server system including at least two domains, comprising the steps of: receiving, from a first browser view of the web browser, a request to view a web page including trusted and untrusted content, wherein the web browser supports a cross-frame security feature; transmitting, from the first domain of the web server system, a first document including the trusted content, responsive to the request, to the web browser; transmitting, from the second domain of the web server system, a second document including the untrusted content, further responsive to the request, to the web browser; and instructing the web browser to display the first document in a first browser view and the second document in a second browser view; such the web browser prevents the first and second documents from substantially interacting. In certain circumstances, it is desirable, however, to allow the first and second documents to exchange certain predetermined information, such as a document title or window size. To that end, the present invention further provides a method for securely displaying and exchanging information between first and second documents served from a first and a second domain, respectively, comprising the steps of: receiving, in a first browser view of a web browser supporting a cross-frame security feature, the first document from the first domain; receiving, in a second browser view, the second document from the second domain, wherein the second document includes predetermined information that is to be passed to the first document; creating a first URL that includes the information from the second document that is to be passed to the first document; and sending the first URL to the first domain via a third browser view. The method may further include the steps of receiving, in one of the first and third browser views, data from the first domain that is responsive to the information included in the first URL. The method may still further include creating a second URL including information to be passed to the second document; and sending the second URL to the second domain. In this way, predetermined data may be passed to and/or from the first and/or second documents on the web browser. The invention further provides a method of securely communicating data between first and second documents served from a first and second domain, respectively, comprising the steps of: transmitting a first document from the first domain to a first browser view in a web browser supporting a cross-frame security feature, wherein the first document includes an instruction to the web browser to obtain, via a second browser view, a second document from a second domain; receiving, from a third browser view of the web browser, a URL including information derived from the second document; and parsing the URL to extract the information derived from the second document. Preferably, the invention further includes transmitting, based on the information extracted from the URL, additional content from the first domain to the web browser. This additional content may further include an instruction to the the web browser (a) to create a second URL containing predetermined information from the first domain and (b) to send the second URL to the second domain. Apparatuses and computer program products for carrying out the present invention are also provided. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial of a prior web page in an online person-to-person auction. FIG. 2 is a block diagram of an exemplary computer system upon which the present invention may be implemented. FIG. 3 is a block diagram depicting a simplified client-server environment in which online communication may take place. FIGS. 4A and 4B are pictorials of a web page for inputting an item description in accordance with the invention. FIG. 5 is a block diagram of a web server system in accordance with the invention. FIG. 6 is a pictorial of a web page in an online person-to-person auction in accordance with the invention. FIG. 7 is a block diagram and flow chart depicting communication between two documents in accordance with the invention. FIG. 8 is a HTML-based page representation depicting multiple browser views capable of exchanging information in accordance with the invention. DETAILED DESCRIPTION OF THE INVENTION In the following presentation, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one of ordinary skill in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form. As stated above, the present invention provides a method and apparatus for securely communication and exchanging trusted and untrusted content between a web server system and a client computer. FIG. 2 is a block diagram showing an example computer 200 within which various functionalities described herein can be fully or partially implemented. Computer 200 can function as a server in a web server system, a personal computer, a mainframe, or various other types of computing devices. It is noted that computer 200 is only one example of computer environment and is not intended to suggest any limitation as the scope or use or functionality of the computer and network architectures. Neither should the example computer be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in FIG. 2. Computer 200 may include one or more processors 202 coupled to a bus 204. Bus 204 represents one or more of any variety of bus structures and architectures and may also include one or more point-to-point connections. Computer 200 may also include or have access to memory 206, which represents a variety of computer readable media. Such media can be any available media that is accessible by processor(s) 202 and includes both volatile and non-volatile media, removable and non-removable media. For instance, memory 206 may include computer readable media in the form of volatile memory, such as random access memory (RAM) and/or non-volatile memory in the form of read only memory (ROM). In terms of removable/non-removable storage media or memory media, memory 206 may include a hard disk, a magnetic disk, a floppy disk, an optical disk drive, CD-ROM, flash memory, etc. Any number of program modules 207 can be stored in memory 206, including by way of example, an operating system 208, off-the-shelf applications 210 (such as e-mail programs, web browsers, web server applications, etc.), program data 212, and other modules 214. Memory 206 may also include one or more databases 114 containing data and information enabling functionality associated with program modules 112. A user can enter commands and information into computer 200 via input devices such as a keyboard 216 and a pointing device 218 (e.g., a “mouse”). Other device(s) 220 (not shown specifically) may include a microphone, joystick, game pad, serial port, etc. These and other input devices are connected to bus 204 via peripheral interfaces 222, such as a parallel port, game port, universal serial bus (USB), etc. A display device 222 can also be connected to computer 200 via an interface, such as video adapter 224. In addition to display device 222, other output peripheral devices can include components such as speakers (not shown), or a printer 226. Computer 200 can operate in a networked environment or point-to-point environment, using logical connections to one or more remote computers. The remote computers may be personal computers, servers, routers, or peer devices. A network interface adapter 228 may provide access to network 232 such as when a network is implemented as a local area network (LAN), or wide area network (WAN), etc. In a network environment, some or all of the program modules 207 executed by computer 200 may be retrieved from another computing device coupled to the network. For purposes of illustration, the operating system 208 and off-the-shelf application(s) 210, for example, are illustrated herein as discrete blocks, although it is recognized that such programs and components reside at various times in different storage components remote or local, and are executed by processor(s) 202 of computer 200 or remote computers. FIG. 3 illustrates the various ways in which the computer described in FIG. 2 may be utilized: namely, as a client computer or as a server in a client-server environment such as the World Wide Web (the Web). The terms “client” and “server” are used to refer to a computer's general role as a requestor of data (the client) or provider of data (the server). Web clients 305 and Web servers 310 communicate using a protocol such as the HyperText Transfer Protocol (HTTP). In the Web environment, web browsers reside on clients and render Web documents (pages) served by the Web servers. The client-server model is used to communicate information between clients 305 and servers 310. Web servers 310 are coupled to the Internet 300 and respond to document requests and/or other queries from web clients 305. When a user selects a document by submitting its Uniform Resource Locator (URL), a web browser, such as Netscape Navigator or Internet Explorer, opens a connection to a server 310 and initiates a request (e.g., an HTTP GET) for the document. The server 310 delivers the requested document, typically in the form of a text document in a standard markup language such as HyperText Markup Language (HTML). The HTML document may contain text, graphics, audio clips, and video clips, as well as metadata or commands providing formatting information. It also may include embedded “links” that reference other data or documents located on the web clients 305 or servers 315. In addition, HTML documents may contain embedded software components containing program code that perform a wide variety of operations, such as manipulating data and playing audio or video clips. Example software components include ActiveX, Java, JavaScript and VBScript components. The web browser on client 305 executes each script and/or software component as it reaches the position in the script during interpretation of the HTML document. As described above, conventional electronic marketplace services include an item description (as embedded HTML) in a web page listing an item or service for sale (“item listing page”). This item description may include malicious software components that attempt to alter the content provided by the service (e.g., logos, links, cookies, etc.). The present invention solves this problem by separating “trusted” item listing information (e.g., a header or description that is created by the electronic marketplace service) from “untrusted” item description information supplied by a seller who may have bad intent. In one embodiment of the invention, the separation of trusted content from untrusted content may take place upon receiving an item description from a seller. By way of example, FIGS. 4A and 4B show an item input screen 400, at which a seller may input information concerning an item he wishes to offer for sale. The seller is prompted to enter information such as his User ID 405, password 410, the title of the item for sale 415, the item location 420, the category of the item 425, accepted payment methods 430, shipping terms 440, the item description in HTML format 445, the location that a picture may be found 450, the quantity available 455, the minimum bid 460, and duration of the listing 465. In accordance with the invention, certain seller-entered information may be deemed “trusted” while other information may be deemed “untrusted.” For example, some fields on the item listing screen 400 require the seller to pick from predetermined “safe” options. At the Accepted Payment Methods 430 field, for example, the seller is required to check a box next to one of the following limited options: Money Order/Cashier's Check; COD; See Item Descrption, Personal Check; On-line Escrow; Other; Visa/Mastercard; American Express; and Discover. Because the options are predetermined, there is no opportunity for an ill-intentioned seller to include malicious code in his response. Thus, such information may be deemed “trusted.” By comparison, other seller-provided information may be deemed “untrusted.” Untrusted content is content that has the potential to include malicious code. For example, the Item Description field 445 may be in HTML format, which may include malicious code such as scripts or tags, as described above. In a preferred embodiment of the invention, the trusted content and the untrusted content relating to an item listing are stored on a web server system including two separate servers. FIG. 5 depicts an example of such a system. Server system 500 preferably includes a listing server 510 and a description server 550, each in communication with the other via communication link 540. Each includes a management process 520, 560 and a database 530, 570. Listing server 510 and description server 550 are further in communication with a web browser 590 in client computer 580 via a communication medium such as the World Wide Web. In operation, in this preferred embodiment, the listing management process 520 in listing server 510 interacts with a seller using a client computer 580, e.g., by “serving” the item input screen described above with reference to FIGS. 4A and 4B. Listing management process 520 then receives the seller's item information and distinguishes between trusted and untrusted content in a predetermined fashion such as that described above, e.g., by field. In accordance with the invention, trusted content is stored in the listing database 530, while untrusted content is passed via communication link 540 to the description management process 560 in description server 550. Description management process 560 then stores the untrusted content in the description database 550. In further accordance with the invention, when a potential buyer seeks to view an item listing via web browser 590 on client computer 580, web browser 590 sends a request to listing server 510 for the corresponding item description screen. Listing management process 520 on server 510 receives the request, retrieves appropriate “trusted” information from listing database 530 and provides this information to the web browser in the form of an HTML document. Web browser 590 renders this document in the ordinary manner in the primary view of the web browser. The primary view of a web browser, as used here, is the view that generates the initial request for the web page encompassing both trusted and untrusted content. For the purpose of the invention, a browser view may include, e.g., a window, a subwindow, a dialog box, a frameset, a frame, and an inline floating frame. In accordance with the invention, one of the lines in the “trusted” document is an HTML instruction to the web browser 590 to create a secondary browser view. The secondary browser view is then directed to load some or all of the untrusted content from description server 550 and to display it in the secondary browser view. For example, the secondary browser view may be created by the HTML tags <IFRAME NAME=“DescriptionView510” SRC=http://Description ServerAddress/DescriptionPath/ItemDescription.HTM></IFRAME>. If the untrusted content is in HTML format, it will then “render” within the secondary browser view, in a similar manner to the manner in which such content is rendered on conventional pages that included it as embedded content. FIG. 6 depicts an exemplary web page, wherein the primary browser view is shown as view 600 and the secondary browser view is shown as view 610. In this example, item description 114 (provided by the seller) is deemed “untrusted” and is accordingly displayed on web browser 590 within a second view 610 of the web browser. Advantageously, the viewable length of item description 114 is now constrained by the size of secondary browser view 610. If item description 114 is “longer” than the view size, scroll bar 520 can be used to navigate within it. In accordance with the present invention, web browser 590 preferably supports a cross-frame security feature. This feature is a security restriction that has been implemented in certain recent web browser programs, including, e.g., versions 4.0 and later of Microsoft Corporation's Internet Explorer®, as well as other browser programs. This restriction relates to the interaction of Web pages that are joined together to form HTML framesets. An HTML frameset consists of a collection of frames that allow creation of multiple document windows within one browser. Each frame appears to act like a separate browser window, displaying multiple information sources simultaneously. Within each frame, a user can scroll up and down, and perform all the things that a user would normally do within a single browser window. The links in a frame can control what is displayed in other frames or windows. In Internet Explorer®, for example, pages of an HTML frameset may only interact if the domain components of the URL addresses refer to the same top-level or second-level domain. If the HTML pages in two frames have different domain names, however, the web browser prevents them from substantially interacting. For example, Internet Explorer® prevents any attempt to read out or modify content between frames served from different domains, but allows access required to instruct a frame or subframe to navigate to a particular URL address that is beyond the domain restriction. Any attempt by a document that attempts to access parts of another document in violation of the cross-frame security feature of the browser is automatically blocked by a “permission denied” error. In further accord with the present invention, the domain names of the listing server and the description server are different, so that content from each server is blocked by the browser security feature from substantially interfering with content in the other. The preferred relationship between the domain names will, of course, depend on the cross-frame security feature of the web browser(s) for which the system is designed. For example, under the cross-frame security feature of Microsoft Internet Explorer®, as long as two servers (e.g., listing server 520 and description server 550) do not share top-level or second-level domain names, the content served from those servers will be prevented from substantially interacting (assuming that the content from each server is served via a separate web view of the receiving web browser). Accordingly, the present invention contemplates two servers having different domain addresses. For example, listing server 520 may be assigned the domain name “ebay.com,” while description server 550 may be assigned the domain name “not-ebay.com.” In an alternative embodiment, a single server may be provided with two domain addresses. In this embodiment, the trusted and untrusted content could be stored on a single server, and perhaps even in a single database, but still be “served” from two separate logical domains. There has thus been described an electronic marketplace system in which auction-related content may be displayed in one window of a customer's web browser while item-related content is displayed in a second window of the customer's web browser, such that the auction-related content and the item-related content are prevented from substantially interacting. In certain circumstances, it may be desirable, however, to allow two documents served from two different domains to two frames of a web browser to exchange certain predetermined information. For example, in the online auction listing described in FIG. 6, it may be desirable to make the size of the item description view 610 either larger or smaller, depending on the amount of the description content provided by the seller to be displayed in the description view 610. Because the item listing page contains two views 600, 610, and because the content displayed in each view is served from two different domains, a web browser supporting a cross-domain security feature will prevent the two views from exchanging such information, as described above. Accordingly, the present invention further provides a method to exchange certain predetermined information between two documents in two browser views served from different domains. This aspect of the invention makes use of the full access privileges that are allowed between frames that serve documents from the same top-level or second-level domain, and the limited access privileges that are permitted even between frames serving documents from different domains. More specifically, Internet Explorer® permits a first document in one frame to freely script content into and out of a second document in another frame, where the first and second documents are served from the same domain. Internet Explorer further permits a first document in one frame to direct another frame to navigate to and render a second document, even where the two documents are served from different domains, if the instruction is passed as a URL. Embodiments of the present invention contemplate using a third frame to mediate between two documents by passing information from a document served from a first domain to a second document served from a second domain, without interfering with the simultaneous display of the two documents on a web browser. FIGS. 7 and 8 depict a method of passing data between two documents served in two frames from two different domains in accordance with the invention. The method starts at a first browser view 702 that receives a first document Doc1 from a first domain, Domain1, at an Internet address http://www.ebay.com/doc1.html. By way of example, document Doc1 may be an item description screen as shown in FIG. 5. Preferably, document Doc1 is an HTML document that includes an instruction to the web browser to create a new browser view and to display item description information in the view (view 610 in FIG. 6; view 706 in FIG. 8). This may be accomplished via an HTML IFRAME statement (step 704 on FIG. 7), which passes to the new IFRAME a URL address at which a second document Doc2 containing the item description may be obtained (e.g., http://www.not-ebay.com/doc2.html). Step 704 thus results in the creation of a new inline floating frame (“Iframe”) 706 and the rendering of document Doc2 in view 706. (Because documents Doc1 and Doc2 are served from domains “ebay.com” and “not-ebay.com,” respectively, at this point they are prevented by the browser's cross-domain security feature from directly exchanging information.) In further accordance with the invention, document Doc2 contains certain predetermined information to be passed back to document Doc1 (e.g., the preferred size of the IFRAME containing document Doc2). The predetermined information may include information that is either contained within document Doc2 (e.g., a variable definition such as “PreferredSize=3 lines”) or information that may be derived from document Doc2 as the web browser renders document Doc2 in view 706. Document Doc2 further includes an instruction to the web browser to create (at step 708) yet another inline floating frame (view 710). The instruction of step 708 preferably includes a URL reference that directs view 710 to navigate to and render a third HTML document, Doc3, located on domain Domain1 at http://www.ebay.com/doc3.html. In accordance with the invention, the instruction of step 708 also includes the information to be passed to document Doc 1. This information may be appended to the URL reference as a conventional “query string.” Thus, the URL reference would be of the form http://www.ebay.com/doc3.html?data1tobepassed=data1value&data2tobep assed=data2value For example, if the information to be passed from document Doc2 to document Doc1 is the preferred frame size for document Doc2, the URL reference would be http://www.ebay.com/doc3.html?size=PreferredSize. In accordance with the instruction from document Doc2 in view 706, the web browser via view 710 sends the URL request to domain 1 for document Doc3. Notably, at this point, the query-string data from document Doc2 has now been transmitted to the server at domain Domain 1. Preferably, however, the server at domain Domain1 returns a document Doc3 to view 710 that is then rendered. The returned document Doc3 preferably includes the query-string data and also a simple script-based parser such as those ordinarily employed in web page development. The parser in document Doc3 extracts from the URL query string the data that is to be passed to document Doc1. At this point, document Doc3 (a document served from domain Domain1) possesses information originating from document Doc2 (a document served from domain Domain2) that is to be passed to document Doc1 (also served from domain Domain1). Because the web browser's cross-domain security feature permits free access between documents on the same domain, in step 712 document Doc1 is able to access and send the information directly to document Doc1, using document objects made available by document Doc1 in accordance with the well-known Document Object Model of Dynamic HTML. Document Doc1 may then act on that information, e.g., by dynamically adjusting the size of view 706. Should there be responsive information from document Doc1 to be sent to document Doc2, a similar procedure is followed, either (1) by causing view 710 to be directed to a fourth document Doc4 served from domain Domain2 or (2) by creating a fourth browser view 718. If the former approach is used, at step 714 document Doc1 sends the responsive information to document Doc3 in view 710, either as an URL reference having a query string or by directly accessing the document objects made available by document Doc3 and thereby causing document Doc3 to construct a URL reference having the information to be sent to document Doc2 attached in a query string. At step 716, the URL reference causes view 710 to request and render document Doc4 from domain Domain2 at location http://www.not-ebay.com/doc4.html?datatobepassed, using the query string information from document Doc1. Document Doc4 in turn is obtained from the address specified, and, when rendered by view 710, includes instructions to the web browser to parse the query string data from document Doc1 and (at step 720) pass it to document Doc2 using the document objects made available by document Doc2. If the latter approach is used, alternatively, the responsive information from document Doc1 is passed to document Doc2 via a new web browser view 718. The new browser view 718 may be created by either of documents Doc1 or Doc3 by an IFRAME instruction that includes a URL reference having a query string containing the data from document Doc1 to be passed to document Doc2. Regardless of which document (Doc1 or Doc3) creates the new view 718, document Doc4 on domain Domain2 ultimately is requested and obtained from the URL address specified, and, when rendered by view 718, includes instructions to the web browser to parse the query string data from document Doc1 and pass it to document Doc2 using the document objects made available by document Doc2. In this way, there is provided a method for securely passing data between two documents served from two different domains and viewed on two separate Is views of a client web browser. It will be appreciated that the parsing function described in the above method may be implemented on the server side, rather than at the client. In this alternative, a URL containing data to be passed would be parsed by the server hosting the domain receiving the URL (e.g., the parsing described above as occurring at document Doc3 itself could be performed by the server at domain Domain1). In this alternative embodiment, document Doc3 in view 710 could serve simply to pass the URL containing the data on to the server hosting domain Domain1, rather than itself performing the parsing. It will further be recognized that document Doc4 may be similarly handled. It will be further appreciated that any of documents Doc1, Doc2, Doc3 and Doc4 may be dynamically-served documents that may be modified or updated by the server that hosts them, based on the data that is passed from document to document. In a further embodiment, an HTML “form” may be used to pass data among the various documents and servers described above instead of a query string. For example, document Doc2 may create and populate a “form” data structure that could then be “posted” or sent to document Doc3 on the server hosting domain Domain1, with the associated results of the post operation being returned to view 710. An example of HTML code that may be used in document Doc2 to generate and post the form is as follows: <iframe id=“dataIFrame” name=“dataIFrame”></iframe> <form name=“dataForm” method=“post” target=“dataIFrame” action=“http://www.ebay.com/doc3.html”> <input type=“hidden” name=“data1” value=“value”> <input type=“hidden” name=“data2” value=“value”> </form> <script language=“javascript”> document.forms[“dataForm”].submit( ); </script> Note that the form “method” attribute may be either “get” or “post” in this embodiment. The method for transmitting information between documents Doc1 and Doc2 in accordance with the present invention may also be described from the perspective of one of the web servers that host the documents. From the perspective of the server hosting document Doc1 on domain Domain 1, for example, the first step is transmitting document Doc1 from the first domain to a first browser view 702 in the web browser, where document Doc1 includes an instruction to the web browser to obtain, via a second browser view 706, a second document Doc2 from a second domain. The server at domain Domain1 then receives, from a third browser view 710 of the web browser, a URL (or form data block) including information derived from the second document. The server may then parse the URL to extract the information derived from the second document. Next, the server transmits, based on the information extracted from the URL or form, additional content from the first domain to the web browser. The additional content may further include an instruction to the web browser (a) to create a second URL or form containing predetermined information from the first domain and (b) to send the second URL or form to the second domain. It should be noted that the techniques and functionality provided by the present invention are described herein in the general context of computer-executable instructions, such as HTML “documents,” executed or “rendered” by one or more computers (one or more processors) or other devices. It will be appreciated that although certain embodiments described above refer to embedded HTML code, the invention is not limited solely to an environment supporting HTML or document objects. Rather, the present invention is applicable in any environment in which malicious executable code is embedded in a document viewable by a browser on a computer. In addition, computer-executable instructions generally include routines, programs, objects, components, data structures, logic, etc. that perform particular tasks or implement particular abstract data types. Typically, the functionality of the computer-executable instructions may be combined or distributed as desired in various embodiments. It is noted that a portion of a set of computer-executable instructions may reside on one or more computers operating on a system. An implementation of these computer-executable instructions and techniques may be stored on or transmitted across some form of computer readable media. Computer readable media can be any available media that can be accessed by a computer. By way of example, and not limitation, computer readable media may comprise volatile and non-volatile media, or technology for storing computer readable instructions, data structures, program modules, or other data. In the foregoing specification, the invention has been described with reference to specific embodiments. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Electronic marketplaces, such as the person-to-person trading system pioneered by eBay, Inc., have become a well-known way to buy and sell goods and services via the Internet. Typical electronic marketplace systems allow sellers to enter a description of the item or service they wish to offer through an online auction. This item description may be in text or HTML format and is then stored on the electronic marketplace system. When a prospective buyer wishes to view the item (or service) that is being offered, he directs his web browser to download and display the appropriate item listing web page from the electronic marketplace system. The item listing web page typically is an HTML document that includes not only the seller's item description but also other content provided by the electronic marketplace service. FIG. 1 shows an example of such a web page. In addition to the item description 114 , the item listing document may include, e.g., an item title 100 (“Sample Item for Sale”), a minimum starting bid 102 , the time remaining before the auction ends 104 , the auction start time 106 , the bid history 108 , the item location 110 , the shipping summary 112 , detailed instructions concerning shipping and handling 116 , payment methods accepted 118 , legal disclaimers 120 , an item number 122 , and seller information 124 such as the seller's feedback rating. As noted above, the item listing web page is normally an HTML document that includes not only content provided by the electronic marketplace service, but also the seller-provided item description, which may itself contain executable code, e.g., HTML code. For example, the item description 114 on FIG. 1 (“*** Sample HTML item description ***”) was produced by the following HTML code: <br> * * * <br> <b>Sample HTML item description</b> <br> * * * Thus, the web browser on the potential buyer's computer “renders” both the service-provided HTML content and the seller-provided HTML content. There is, however, an undesirable byproduct of permitting sellers to describe their items or services using embedded code. For example, a malicious seller might include HTML code that makes use of malicious HTML tags or scripts to alter the content provided by the auction service. For example, a malicious seller might attempt to replace a particular logo with a different image or try to divert private information that a potential buyer might provide to the auction service (e.g., cookie information). These risks associated with embedded code have been widely recognized among web site providers. For example, the Department of Energy's Computer Incident Advisory Capability has reported that “[m]ost web browsers have the capability to interpret scripts embedded in web pages downloaded from a web server. Such scripts may be written in a variety of scripting languages and are run by the client's browser . . . . In addition to scripting tags, other HTML tags . . . have the potential to be abused by an attacker . . . to alter the appearance of the page, insert unwanted or offensive images or sounds, or otherwise interfere with the intended appearance and behaviour of the page.” CIAC Information Bulletin K-021. An approach that is conventionally used to address the risks associated with embedded content is to filter out potentially malicious code from within the embedded content. For example, a filter program might search the embedded code for <script> </script> HTML tags and delete any code that lies between the tags. A difficulty with this approach, however, is that a filter program may still fail to eliminate all of the potentially dangerous characters in the embedded code. Alternatively, the filter program may filter out too much material. In the above example, the filter program would prevent any and all scripts whatsoever from executing, including scripts that may be desirable or beneficial. Thus, a long-felt need exists for a way to display both trusted content (e.g., the auction-service HTML content) and untrusted content (e.g., the seller-provided HTML content), while at the same time preventing the untrusted content from modifying or manipulating the trusted content. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention solves this problem of embedded code by separating trusted and untrusted content on a web page served from a web server system to a web browser on a client computer. In accordance with the invention, the trusted and untrusted content is stored on separate network domains in the web server system. When the user requests the web page via a web browser, the user's web browser is instructed to display the trusted content in one browser window, and the untrusted content in a second browser view. As long as the web browser supports a cross-frame security feature, the web browser then prevents the trusted and untrusted content from substantially interacting. Thus, the present invention provides a method for separating content on a web server system comprising the steps of receiving a first set of content from a first source; storing the first set of content on a first domain of the web server system; receiving a second set of content from a second source; and storing the second set of content on a second domain of the web server system; such that if the first and second sets of content were transmitted to a web browser supporting a cross-frame security feature and displayed in two separate browser views, the web browser would prevent the first and second sets of content from substantially interacting. The present invention further provides a method for securely communicating content to a user's web browser from a web server system including at least two domains, comprising the steps of: receiving, from a first browser view of the web browser, a request to view a web page including trusted and untrusted content, wherein the web browser supports a cross-frame security feature; transmitting, from the first domain of the web server system, a first document including the trusted content, responsive to the request, to the web browser; transmitting, from the second domain of the web server system, a second document including the untrusted content, further responsive to the request, to the web browser; and instructing the web browser to display the first document in a first browser view and the second document in a second browser view; such the web browser prevents the first and second documents from substantially interacting. In certain circumstances, it is desirable, however, to allow the first and second documents to exchange certain predetermined information, such as a document title or window size. To that end, the present invention further provides a method for securely displaying and exchanging information between first and second documents served from a first and a second domain, respectively, comprising the steps of: receiving, in a first browser view of a web browser supporting a cross-frame security feature, the first document from the first domain; receiving, in a second browser view, the second document from the second domain, wherein the second document includes predetermined information that is to be passed to the first document; creating a first URL that includes the information from the second document that is to be passed to the first document; and sending the first URL to the first domain via a third browser view. The method may further include the steps of receiving, in one of the first and third browser views, data from the first domain that is responsive to the information included in the first URL. The method may still further include creating a second URL including information to be passed to the second document; and sending the second URL to the second domain. In this way, predetermined data may be passed to and/or from the first and/or second documents on the web browser. The invention further provides a method of securely communicating data between first and second documents served from a first and second domain, respectively, comprising the steps of: transmitting a first document from the first domain to a first browser view in a web browser supporting a cross-frame security feature, wherein the first document includes an instruction to the web browser to obtain, via a second browser view, a second document from a second domain; receiving, from a third browser view of the web browser, a URL including information derived from the second document; and parsing the URL to extract the information derived from the second document. Preferably, the invention further includes transmitting, based on the information extracted from the URL, additional content from the first domain to the web browser. This additional content may further include an instruction to the the web browser (a) to create a second URL containing predetermined information from the first domain and (b) to send the second URL to the second domain. Apparatuses and computer program products for carrying out the present invention are also provided. | 20040709 | 20121002 | 20060112 | 67965.0 | G06F1730 | 0 | WEST, THOMAS C | METHOD AND APPARATUS FOR SECURELY DISPLAYING AND COMMUNICATING TRUSTED AND UNTRUSTED INTERNET CONTENT | UNDISCOUNTED | 0 | ACCEPTED | G06F | 2,004 |
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10,888,812 | ACCEPTED | Infrared night vision system, in colour | The invention concerns a night vision method and system for a road scene comprising at least one projection device emitting an infrared light towards the road scene and a first sensor for capturing a first image of the road scene, this sensor being a colour sensor. | 1. Night vision system for a road scene comprising at least one projection device emitting an infrared light towards the road scene and a first sensor for capturing a first image of the road scene, the first sensor being a colour sensor. 2. System according to claim 1, which comprises a second monochrome sensor for capturing a second infrared image of the road scene, the first image being a colour image and the second image being a monochrome image. 3. System according to claim 2, which comprises image processing means for combining the first colour image with the second monochrome image. 4. System according to claim 2, wherein the second sensor is a sensor with high sensitivity, in particular to infrared radiation. 5. System according to claim 2, wherein the first sensor has a sensitivity, in particular to infrared radiation, less than that of the second sensor. 6. System according to claim 1, which is mounted in a motor vehicle. 7. Road scene night vision method, in which an infrared light beam is emitted in the direction of the road scene, which comprises the following operations: capturing a first colour image of the road scene, capturing a second monochrome infrared image of the road scene, combining the first and second images of the road scene, and obtaining a colour infrared image of the road scene. 8. Method according to claim 7, wherein the combining of the first and second images comprises a pixel by pixel averaging of the said first and second images. 9. Method according to claim 7, wherein the capture of the second image is performed with a high infrared sensitivity. 10. Method according to claim 7, wherein the capture of the first image is performed at an infrared sensitivity less than that of the second image. | FIELD OF THE INVENTION The invention concerns a night vision system for motor vehicles. This night vision system, of the infrared type, makes it possible to produce images, at blast partly in colour, of the road scene unfolding in front of the vehicle. The invention also concerns a method of implementing this system. The invention finds applications in the field of vehicles travelling on the road such as for example cars. It finds in particular applications in the field of night vision for such vehicles. BACKGROUND OF THE INVENTION Having regard to the large number of vehicles travelling on the roads, it is necessary to procure, for these vehicles and their drivers, the best possible adapted road vision in order to reduce risks of accidents. In particular at night, it is important for the driver to be able to have sufficiently detailed vision of the road extending in front of him as well as the sides of this road. In other words, for questions of safety, it is sought to improve the night vision of the road scene for the driver of the vehicle. For this, there exist night vision systems in which a lighting device, of the spotlight type, emits an infrared light beam in the direction of the road, in front of the vehicle. This infrared light is reflected by the various objects situated in the road scene. This reflection of the infrared light is more or less intense according to the nature of the object and its distance with respect to the lighting device. A sensor sensitive to infrared radiation, situated generally in the vehicle, provides capture of this infrared radiation. It then supplies an infrared image of the road scene extending in front of the vehicle. Such a system, with the emission of infrared radiation, reflection of these rays and capture of the reflected rays, is referred to as an “active system”. It makes it possible to detect the near infrared, that is to say the radiation having a wavelength which may attain 1100 nm. An example of an image obtained with an active system is shown in FIG. 1. This image makes it possible to detect a vehicle with a pedestrian on the road alongside the vehicle. However, it is not possible to determine whether the lights of this vehicle are the front lights or the brake lights of the vehicle. It is therefore not possible to know in which direction the vehicle is placed. This image also makes it possible to see light spots on the right of the road; these light spots seem to be road signs, but it is impossible to read the information written on these panels. There also exist systems for detecting far infrared. These systems are called “passive systems”. In these systems, a sensor captures the far infrared light, that is to say radiation having a wavelength of around 10 μm. Such systems make it possible to capture only the infrared radiation emitted by the objects themselves. In other words, it is a case of measuring the temperature of the elements in the road scene. In such a passive system, the sensor captures the head detected, as an infrared light. One example of an image obtained by a passive system is shown in FIG. 2. This image makes it possible to display a first vehicle and, further away, a second vehicle with pedestrians close by. However, it is not possible to determine, on this image, whether the lights of these vehicles are the front lights or the brake lights. It is therefore not possible to know in which direction these vehicles are placed. All these systems have drawbacks. In particular, the passive systems cannot detect cold objects. This drawback is aggravated further when moving objects, sharing the same space as the vehicle, are invisible. This is the case in particular with cars which are still cold, which have been travelling only for a few moments and where the glasses on the rear lights have not had time to heat up. This is because the large quantity of far infrared radiation emitted by the lamps of the rear lights pass through neither plastic nor glass. Likewise, the illumination of the brake lights, the direction indicators or the hazard warning lights do not instantaneously heat up the glass of the said light. They are therefore undetectable by a passive system. On the other hand, active systems react too well to light sources such as the rear lights of vehicles, three-coloured lights on the road, etc. These lights, emitting infrared radiation, dazzle the sensor and create a kind of halo of light all around the image of the object in question, which makes the contour of the object undefined. This dazzle is referred to as “blooming”. Moreover, with these active or passive systems, the road scene is seen at wavelengths which are outside the visible spectrum and therefore by nature foreign to the concept of colour. The image of the road scene obtained by these systems is therefore monochrome (that is to say black and white) with various levels of grey, the light levels corresponding to the objects emitting or reflecting infrared and the dark levels corresponding to the objects not emitting or reflecting infrared. However, with a monochrome image, it is sometimes difficult to know precisely what type of object is concerned. For example, on the images in FIGS. 1 and 2, it is not possible to detect whether it is a case of front or rear lights of the vehicles. Likewise, it is not possible to read the information written on the road signs. Active or passive systems attempt to remedy these drawbacks by processing the captured image before displaying it. One of these processings consists of a video reversal of the image. This video reversal makes the objects detected as dark light and makes the objects detected as bright dark. An example of an image processed by video reversal is shown in FIG. 3. In this example, the video reversal makes it possible to display the road scene better and to better imagine to what each object in the road scene corresponds. In this example, the video reversal makes it possible to show that the first vehicle is coming in the opposite direction and that the second vehicle is stationary in the same direction as the vehicle in which the system is mounted. Another processing of the image captured proposes to artificially colour the image of the road scene. This treatment consists of associating with each level of grey of the image captured, an artificial and arbitrary colour. This operation is known, in image processing, by the name “application of an LUT (look-up table)”. The image obtained is called a “false-colour image” since the colours visible on the image are artificial colours which do not correspond to the real colours. For example, the colour red can be associated with a high level of grey and the colour blue with a very low level of grey. The intermediate levels of grey are associated with colours graduated between red and blue. It will thus be understood that, for example, a light situated facing the sensor will have a necessarily red image (high level of grey). It will not therefore be possible to know whether it is a case of a dipped headlight of a vehicle or a brake light. It is therefore not possible to exactly interpret the objects situated in the road scene in front of the vehicle. In other words, these colouring operations may make it possible to improve the perception of an image by revealing information which a simple monochrome display does not make it possible to identify. They do nevertheless remain artifices and in no way render the true colour of the objects. For example, in the case of infrared night vision, objects with the same visible colour (for example green) may have radically opposed behaviours in infrared. One may appear bright or light because, apart from the wavelengths giving it its green colour, the object reflects near infrared (active system) or, because of its temperature, emits far infrared (passive system). The other may appear dark because it absorbs the near infrared and, because of its low temperature, does not emit far infrared. SUMMARY OF THE INVENTION The aim of the invention is precisely to remedy some or all of the drawbacks of the techniques disclosed above. To this end, it proposes a night vision system for producing a colour infrared image of the road scene situated in front of the vehicle. For this purpose, the invention proposes to use a colour sensor. The invention preferably concerns a night vision system for a road scene comprising at least one projection device emitting infrared light towards the road scene and a first sensor for capturing a first infrared image of the road scene, the sensor being a colour sensor. Advantageously, the colour sensor is a sensor detecting radiation at least in the visible range, in particular mainly in the visible range. The device emitting infrared radiation may, for example, be chosen from amongst one or more incandescent lamps, one or more light-emitting diodes functioning in the infrared or one or more laser diodes. In another preferred embodiment of the invention, it is also sought to avoid the dazzling which is obtained by means of a conventional active system. For this purpose, the invention proposes to associate, with the first colour sensor, a second monochrome sensor. More precisely, this preferred embodiment proposes a system comprising a second monochrome sensor for capturing a second infrared image of the road scene, the first image being a colour image and the second image being a monochrome image. Advantageously, the monochrome sensor is a sensor detecting radiation at least in the infrared wavelengths. It can also detect other radiation, in particular in the visible range. Optionally, it is also possible to have recourse to a visible light source, which can in fact be the vehicle headlights, when these are functioning in particular in dipped beam mode. The invention also concerns a method for using the night vision system of the invention. It is a case of a night vision method for a road scene in which an infrared light beam is emitted in the direction of the road scene, with the following operations: capturing a first colour image of the road scene, capturing a second monochrome infrared image of the road scene, combining the first and second images of the road scene, and obtaining a colour infrared image of the road scene. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, already described, depicts an example of a road scene image taken by a conventional active system. FIG. 2, already described, depicts an example of a road scene image taken by a conventional passive system. FIG. 3, already described, depicts an example of a road scene image taken by a passive system and which has undergone video reversal. FIG. 4 depicts an example of a road scene image taken by a highly sensitive monochrome sensor. FIG. 5 depicts an example of a road scene image taken by a colour sensor of low sensitivity. FIG. 6 depicts an example of a road scene image obtained by composition of the images in FIGS. 4 and 5. FIG. 7 depicts schematically the night vision system according to the invention. DESCRIPTION OF EXAMPLES The invention concerns a colour night vision system. This system comprises a device for projecting an infrared light towards the road scene, in front of the vehicle, and at least one sensor for capturing the image of this road scene, this sensor being a colour sensor. In other words, this first sensor, which is placed in or on the vehicle, is a colour sensor capable of capturing a colour image of the road scene. This image is an image in real colours. In a preferred embodiment of the invention, this colour sensor is associated with a second sensor, which for its part is monochrome. In this way, the monochrome sensor, which is a sensor with high infrared sensitivity, captures an infrared image of the road scene. Simultaneously or almost simultaneously, the colour sensor captures a colour image of the road scene. These two images, in colour and infrared, are then combined so as to form one and the same colour infrared image of the road scene. An example of the system of the invention is shown diagrammatically in FIG. 7. This FIG. 7 shows a motor vehicle 10 provided with the night vision system of the invention. This system comprises a device for projecting infrared radiation 11, or projector. As shown in FIG. 7, this projector can be installed for example in one of the front lights of the vehicle. It is also possible to install a projector in each front light of the vehicle. The projector can also be installed in a special housing, for example between the two front lights of the vehicle. The system of the invention also comprises a colour sensor 12. This colour sensor can advantageously be combined with a monochrome sensor 13. In this case, the two sensors are connected together so as to be synchronous or quasi-synchronous. Image processing means, not shown in the figure for reasons of simplification, are connected to the sensors in order to process the images supplied by these sensors. These processing means can be of the electronic type, mounted for example on a PCB dedicated to this processing. They can also be of the computing type, incorporated for example in the on-board computer of the vehicle. In the preferred embodiment, the monochrome sensor is chosen so as to have high sensitivity to the rays which it may detect, in particular to infrared radiation, especially in the near infrared. This sensor is monochrome since, in general terms, current monochrome sensors are appreciably more sensitive than colour sensors. A high-sensitivity sensor can capture the most information possible, with maximum tolerated dazzle. It is considered that a sensor is very sensitive to infrared when it is in particular capable of detecting radiation between 800 and 1200 nm, in particular between 850 and 1100 nm. for example around 1000 to 1100 nm. In order to express more concretely to what such a sensitivity corresponds, it is possible to give the following example: a high-sensitivity sensor is capable of detecting a minimum number of watts, for example equivalent to the energy reflected by a tree trunk at 100 to 200 metres on which an intensity of one or more tens of watts in the 800-1000 nm hand is sent. Thus the image captured by this monochrome sensor is very light and contains most possible information but, on the other hand, it suffers dazzle from adverse sources. On the other hand, the sensitivity of the colour sensor is not preponderant. It is therefore possible to use a colour sensor having a sensitivity less than that of the monochromes sensor, for example a sensitivity 10 to 100 times less high. Such a colour sensor, said to be of low sensitivity, can therefore capture radiation approximately 10 to 100 times greater than that picked up by the high-sensitivity sensor without blooming. “Blooming” will be understood to mean the fact that an image has a spot which is saturated and which is larger than that of the image of the source on the sensor. To take a concrete example, if the tree trunk mentioned above is taken, the sensor said to be insensitive will be able for example to detect it only at approximately 30 metres, while the so-called high-sensitivity sensor could do it at 100 metres, when a sensitivity ratio between the two sensors of approximately 100 is chosen (it is the square of the distance which operates). The image captured by the colour sensor must contain substantially no blooming. All the intense light sources must be point sources and comprise substantially no halo. It is thus possible to obtain an image showing the true light sources without false information due to blooming. These real light sources are then shown in colour. The colour image obtained is essentially composed of coloured spots corresponding to the light sources. The night vision system of the preferred embodiment of the invention is based on the capture of two synchronous or quasi-synchronous images of the same road scene, with substantially different exposure parameters so that: one of the images is of light as is permitted by the monochrome sensor in order to detect the greatest possible information, and the other image is much darker so that only the elements liable to dazzle the light image are in particular visible, and in colour. An example of a light image, captured by the monochrome sensor, is depicted in FIG. 4. This image shows the various elements detected in the road scene by the high-sensitivity sensor. Amongst these elements there can be seen two halos of light 1a and 1b, a third halo of light projected on the ground 2, a pedestrian 3, white lines 8 and 9, signs 4 and 5 and white spots 6a, 6b, 7. An example of a dark image, captured by the colour sensor, is shown in FIG. 5. This image shows solely the elements which were the most dazzling in FIG. 4. Amongst these elements, there can be seen the halos 1a, 1b, 2 and 7 which are shown with hatching to symbolize the colour yellow and the signs 4 and 5 which are shown with flecks to symbolise the colour red. This is because, on a real image of a road scene corresponding to that in FIG. 1 the image taken by the colour sensor would show yellow elements and others red. It will be understood that all the other colours can also appear on the image, for example if a three-colour light is present in the road scene, the bottom light would appear as green in the image and the intermediate light amber. This dark image in FIG. 5 makes it possible in particular to show the inscription on the road signs. It is thus possible to know that it is a case of a stop sign. The monochrome light image and the colour dark image are then combined in order to form only one and the same image of the road scene. This processing can consist of an operation of averaging the two images. In other words, an average is made between each pixel of the colour image and the corresponding pixel of the monochrome image in order to form an infrared image in colour of the road scene. This new image comprises both the information relating to the colours supplied by the colour image and the detailed information supplied by the monochrome image. The fusion or combination of the monochrome light image and the dark image in colour gives a very sensitive image of the road scene (whilst being devoid of any dazzle) and where the light sources and bright objects are coloured. FIG. 6 depicts an example of a road scene image obtained by combining a light monochrome image with a dark colour image. In other words, the image in FIG. 6 is the image obtained by combining the image in FIG. 4 with the image in FIG. 5. In this example, the combination is a pixel by pixel average of the images in FIGS. 4 and 5. This combination can however be other than an average. It may for example be a weighted average or of the type described in the patent filed on 29 Mar. 2002 in France under the filing number 02-04170. This combined image of FIG. 6 shows both the elements which were not very bright in FIG. 4 and the coloured elements in FIG. 5. Thus the pedestrian 3 and the white lines 8 and 9 can be seen. It is also possible to see the yellow front lights 1a and 1b of the vehicle coming in the opposite direction, the reflection on the ground 2 of these front lights and the red road signs 4 and 5 with the inscription “Stop” on the sign 4. In another example of a road scene, a three colour light or rear brake lights or front illuminating lights or direction indicators could appear on the image with a colour corresponding to the actual colour of the said lights. It is therefore very easy for the driver to know which types of light are involved, to be able then to interpret the image and to react according to this interpretation. The invention therefore concerns a very sensitive black and white sensor with a less sensitive colour sensor. It is also possible to use only one colour sensor, then chosen this time so as to be very sensitive. The invention also concerns the motor vehicle equipped with the night vision system according to the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Having regard to the large number of vehicles travelling on the roads, it is necessary to procure, for these vehicles and their drivers, the best possible adapted road vision in order to reduce risks of accidents. In particular at night, it is important for the driver to be able to have sufficiently detailed vision of the road extending in front of him as well as the sides of this road. In other words, for questions of safety, it is sought to improve the night vision of the road scene for the driver of the vehicle. For this, there exist night vision systems in which a lighting device, of the spotlight type, emits an infrared light beam in the direction of the road, in front of the vehicle. This infrared light is reflected by the various objects situated in the road scene. This reflection of the infrared light is more or less intense according to the nature of the object and its distance with respect to the lighting device. A sensor sensitive to infrared radiation, situated generally in the vehicle, provides capture of this infrared radiation. It then supplies an infrared image of the road scene extending in front of the vehicle. Such a system, with the emission of infrared radiation, reflection of these rays and capture of the reflected rays, is referred to as an “active system”. It makes it possible to detect the near infrared, that is to say the radiation having a wavelength which may attain 1100 nm. An example of an image obtained with an active system is shown in FIG. 1 . This image makes it possible to detect a vehicle with a pedestrian on the road alongside the vehicle. However, it is not possible to determine whether the lights of this vehicle are the front lights or the brake lights of the vehicle. It is therefore not possible to know in which direction the vehicle is placed. This image also makes it possible to see light spots on the right of the road; these light spots seem to be road signs, but it is impossible to read the information written on these panels. There also exist systems for detecting far infrared. These systems are called “passive systems”. In these systems, a sensor captures the far infrared light, that is to say radiation having a wavelength of around 10 μm. Such systems make it possible to capture only the infrared radiation emitted by the objects themselves. In other words, it is a case of measuring the temperature of the elements in the road scene. In such a passive system, the sensor captures the head detected, as an infrared light. One example of an image obtained by a passive system is shown in FIG. 2 . This image makes it possible to display a first vehicle and, further away, a second vehicle with pedestrians close by. However, it is not possible to determine, on this image, whether the lights of these vehicles are the front lights or the brake lights. It is therefore not possible to know in which direction these vehicles are placed. All these systems have drawbacks. In particular, the passive systems cannot detect cold objects. This drawback is aggravated further when moving objects, sharing the same space as the vehicle, are invisible. This is the case in particular with cars which are still cold, which have been travelling only for a few moments and where the glasses on the rear lights have not had time to heat up. This is because the large quantity of far infrared radiation emitted by the lamps of the rear lights pass through neither plastic nor glass. Likewise, the illumination of the brake lights, the direction indicators or the hazard warning lights do not instantaneously heat up the glass of the said light. They are therefore undetectable by a passive system. On the other hand, active systems react too well to light sources such as the rear lights of vehicles, three-coloured lights on the road, etc. These lights, emitting infrared radiation, dazzle the sensor and create a kind of halo of light all around the image of the object in question, which makes the contour of the object undefined. This dazzle is referred to as “blooming”. Moreover, with these active or passive systems, the road scene is seen at wavelengths which are outside the visible spectrum and therefore by nature foreign to the concept of colour. The image of the road scene obtained by these systems is therefore monochrome (that is to say black and white) with various levels of grey, the light levels corresponding to the objects emitting or reflecting infrared and the dark levels corresponding to the objects not emitting or reflecting infrared. However, with a monochrome image, it is sometimes difficult to know precisely what type of object is concerned. For example, on the images in FIGS. 1 and 2 , it is not possible to detect whether it is a case of front or rear lights of the vehicles. Likewise, it is not possible to read the information written on the road signs. Active or passive systems attempt to remedy these drawbacks by processing the captured image before displaying it. One of these processings consists of a video reversal of the image. This video reversal makes the objects detected as dark light and makes the objects detected as bright dark. An example of an image processed by video reversal is shown in FIG. 3 . In this example, the video reversal makes it possible to display the road scene better and to better imagine to what each object in the road scene corresponds. In this example, the video reversal makes it possible to show that the first vehicle is coming in the opposite direction and that the second vehicle is stationary in the same direction as the vehicle in which the system is mounted. Another processing of the image captured proposes to artificially colour the image of the road scene. This treatment consists of associating with each level of grey of the image captured, an artificial and arbitrary colour. This operation is known, in image processing, by the name “application of an LUT (look-up table)”. The image obtained is called a “false-colour image” since the colours visible on the image are artificial colours which do not correspond to the real colours. For example, the colour red can be associated with a high level of grey and the colour blue with a very low level of grey. The intermediate levels of grey are associated with colours graduated between red and blue. It will thus be understood that, for example, a light situated facing the sensor will have a necessarily red image (high level of grey). It will not therefore be possible to know whether it is a case of a dipped headlight of a vehicle or a brake light. It is therefore not possible to exactly interpret the objects situated in the road scene in front of the vehicle. In other words, these colouring operations may make it possible to improve the perception of an image by revealing information which a simple monochrome display does not make it possible to identify. They do nevertheless remain artifices and in no way render the true colour of the objects. For example, in the case of infrared night vision, objects with the same visible colour (for example green) may have radically opposed behaviours in infrared. One may appear bright or light because, apart from the wavelengths giving it its green colour, the object reflects near infrared (active system) or, because of its temperature, emits far infrared (passive system). The other may appear dark because it absorbs the near infrared and, because of its low temperature, does not emit far infrared. | <SOH> SUMMARY OF THE INVENTION <EOH>The aim of the invention is precisely to remedy some or all of the drawbacks of the techniques disclosed above. To this end, it proposes a night vision system for producing a colour infrared image of the road scene situated in front of the vehicle. For this purpose, the invention proposes to use a colour sensor. The invention preferably concerns a night vision system for a road scene comprising at least one projection device emitting infrared light towards the road scene and a first sensor for capturing a first infrared image of the road scene, the sensor being a colour sensor. Advantageously, the colour sensor is a sensor detecting radiation at least in the visible range, in particular mainly in the visible range. The device emitting infrared radiation may, for example, be chosen from amongst one or more incandescent lamps, one or more light-emitting diodes functioning in the infrared or one or more laser diodes. In another preferred embodiment of the invention, it is also sought to avoid the dazzling which is obtained by means of a conventional active system. For this purpose, the invention proposes to associate, with the first colour sensor, a second monochrome sensor. More precisely, this preferred embodiment proposes a system comprising a second monochrome sensor for capturing a second infrared image of the road scene, the first image being a colour image and the second image being a monochrome image. Advantageously, the monochrome sensor is a sensor detecting radiation at least in the infrared wavelengths. It can also detect other radiation, in particular in the visible range. Optionally, it is also possible to have recourse to a visible light source, which can in fact be the vehicle headlights, when these are functioning in particular in dipped beam mode. The invention also concerns a method for using the night vision system of the invention. It is a case of a night vision method for a road scene in which an infrared light beam is emitted in the direction of the road scene, with the following operations: capturing a first colour image of the road scene, capturing a second monochrome infrared image of the road scene, combining the first and second images of the road scene, and obtaining a colour infrared image of the road scene. | 20040709 | 20080415 | 20050224 | 75457.0 | 0 | TANINGCO, MARCUS H | INFRARED NIGHT VISION SYSTEM, IN COLOUR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,888,845 | ACCEPTED | Apparatus, system, and method for managing policies on a computer having a foreign operating system | An apparatus, system, and method are disclosed for managing policies on a computer having a foreign operating system. Policies may specify hardware or software configuration information. Policies on a first computer with a native operating system are translated into configuration information usable on a second computer having a foreign operating system. In an embodiment, a translator manager manages the association between the policy on the first computer and the translator on the second computer. Computer management complexity and information technology management costs are reduced by centralizing computer management on the native operating system. Further reductions in management complexity are realized when the present invention is used in conjunction with network directory services. | 1. A signal bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform operations to manage policies on a computer having a foreign operating system, the operations comprising: providing a policy on a first computer having a native operating system; receiving the policy on a second computer having a foreign operating system; and translating the policy to configuration information usable on the second computer. 2. The signal bearing medium of claim 1, wherein providing a policy on the first computer comprises placing the policy in a file system directory. 3. The signal bearing medium of claim 1, wherein providing a policy on the first computer comprises placing a policy locator in a database comprising configuration information. 4. The signal bearing medium of claim 1, further comprising updating selected information on the second computer with the configuration information. 5. The signal bearing medium of claim 4, wherein updating selected information on the second computer comprises updating workstation-specific configuration information. 6. The signal bearing medium of claim 4, wherein updating selected information occurs in response to workstation start-up. 7. The signal bearing medium of claim 4, wherein updating selected information on the second computer further comprises updating user-specific configuration information. 8. The signal bearing medium of claim 7, wherein the user-specific configuration information comprises configuration information selected from the group consisting of organization information, organizational unit information, organizational role information, group information, domain information, domain controller information, country information, locality information, state or province information, site information, profile information, user object information, template information, and alias information. 9. The signal bearing medium of claim 4, wherein setting user-specific configuration information further comprises establishing a precedence of user-specific configuration information. 10. The signal bearing medium of claim 4, wherein updating the selected information occurs in response to user login. 11. The signal bearing medium of claim 1, further comprising editing a policy on the first computer. 12. The signal bearing medium of claim 1, further comprising providing a policy template configured to constrain policy editing on the first computer. 13. The signal bearing medium of claim 1, further comprising registering a plurality of translators on the second computer corresponding to a plurality of policies on the first computer. 14. The signal bearing medium of claim 13, wherein registering the plurality of translators comprises placing the translators in a file system directory. 15. The signal bearing medium of claim 1, further comprising polling a translator to identify configuration information to be translated. 16. The signal bearing medium of claim 15, wherein the polling is conducted at periodic time intervals. 17. The signal bearing medium of claim 1, further comprising polling the first computer to identify modifications to the policy. 18. The signal bearing medium of claim 17, wherein the polling is conducted at periodic time intervals. 19. An apparatus to manage policies on a computer having a foreign operating system, the apparatus comprising: a policy translator configured to receive a policy pertaining to configuration information on a second computer having a foreign operating system; a translator manager configured to manage the association between the policy on the first computer and the translator on the second computer. 20. The apparatus of claim 19, wherein the policy resides on a computer selected from the group consisting of the first computer having a native operating system, the second computer having a foreign operating system, and a third computer. 21. The apparatus of claim 19, wherein the policy is further configured to pertain to a computer workstation. 22. The apparatus of claim 21, wherein the policy is further configured to pertain to a plurality of computer workstations referenced in a directory services container. 23. The apparatus of claim 19, wherein the policy is further configured to pertain to a user. 24. The apparatus of claim 19, wherein the policy is further configured to comprise configuration information selected from the group consisting of organization information, organizational unit information, organizational role information, group information, domain information, domain controller information, country information, locality information, locality information, site information, profile information, user object information, template information, and alias information. 25. The apparatus of claim 19, further comprising at least one policy on the first computer, each policy thereof corresponding to a policy translator on the second computer. 26. The apparatus of claim 19, further comprising a policy editor configured to facilitate creation and editing of policies. 27. The apparatus of claim 19, further comprising a policy template configured to constrain creation and editing of policies. 28. The apparatus of claim 19, wherein the translator manager is further configured to execute the translator in response to the translator manager beginning execution. 29. The apparatus of claim 19, wherein the translator manager is further configured to execute the translator in response to user login. 30. The apparatus of claim 19, wherein the translator manager is further configured to poll the first computer for modifications to the policy. 31. An apparatus to manage policies on a computer having a foreign operating system, the apparatus comprising: means for providing a policy on a first computer having a native operating system; means for receiving the policy on a second computer having a foreign operating system; and means for translating the policy to configuration information usable on the second computer. 32. The apparatus of claim 31, further comprising means for providing a policy template configured to constrain policy editing on the first computer. 33. The apparatus of claim 31, further comprising means for updating selected information on the second computer with the configuration information. 34. A system to manage policies on a computer having a foreign operating system, the system comprising: a first computer having a native operating system; a second computer having a foreign operating system; a directory services database; a communications network configured to facilitate communications between computers and computer peripherals; a policy translator configured to translate the policy to configuration information on the second computer; a translator manager configured to manage the association between the policy on the first computer and the translator on the second computer. 35. The system of claim 34, the system further comprising a policy editor configured to facilitate creation and editing of polices. 36. The system of claim 34, the system further comprising a policy template configured to constrain creation and editing of policies. 37. The system of claim 34 wherein the directory services database resides on the first computer. 38. A method to manage policies on a computer having a foreign operating system, the method comprising: providing a policy on a first computer having a native operating system; receiving the policy on a second computer having a foreign operating system; and translating the policy to configuration information usable on the second computer. 39. The method of claim 37, wherein the instructions further comprise operations to provide a policy template configured to constrain policy editing on the first computer. 40. The method of claim 37, wherein the instructions further comprise operations to update selected information on the second computer with the configuration information. | BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to managing groups of computers and more particularly relates to managing policies for configuring hardware or software settings on groups of computers with a plurality of operating systems. 2. Description of the Related Art A major concern of information technology management in corporations and other organizations has been balancing the complexity associated with managing large numbers of computers with the needs of individual users as they try to accomplish their tasks. A heterogeneous set of computer hardware, operating systems, and application software creates complexity and increased costs, but various combinations of hardware, operating systems, and software provide technical advantages when used as user workstations, departmental servers, corporate infrastructure equipment, and the like. User workstations are particularly difficult to manage when various needs and preferences of individual users are accommodated. For example, an engineer may require the use of a CAD system that runs only on the UNIX™ operating system, where other corporate users may be standardized on the Microsoft Windows™ operating system and associated applications. Many similar compatibility issues exists among current computer systems. One factor that adds to the complexity of managing various operating systems is that different operating systems employ different techniques for setting configuration information. For example, Microsoft Windows™ and applications that run on Windows typically use a database, called the registry, to store configuration information. Computers running the UNIX operating system or derivatives thereof such as LINUX typically store configuration information in plain text files in particular locations in the file system directory. Information technology managers within an organization that uses heterogeneous operating systems typically institute separate sets of management procedures and standards for each operating system used in the organization. One component of prior art solutions to the problem of managing large numbers of computers and users is the use of policies. Policies are used to set configurable options associated with an operating system or application program for a group of computer users. For example, a word processing program may have an option to select an American English dictionary or a British English dictionary. By creating one policy for its users in the United States and another policy for its users in England, an organization can set the appropriate option for all users without configuring each user's computer individually. Another component of prior art solutions to the problem of managing groups of computers and users is the use of network directory services. Directory services provide an infrastructure to store and access information about network-based entities, such as applications, files, printers, and people. Directory services provide a consistent way to name, describe, locate access, manage, and secure information about these resources. The directories associated with directory services are typically hierarchical structures such as a tree with each node in the hierarchy capable of storing information in a unit often referred to as a container. Enterprises may use directory servers and directory services to centrally manage data that is accessed from geographically dispersed locations. For example, corporations typically create network directory trees that mirror their corporate organizations. Information about individual employees, such as their employee number, telephone number, and hire date may be stored in a user object corresponding to each user in the directory tree. An organizational unit container representing each department may contain the user objects associated with each employee in the department. Organizational unit objects associated with each corporate division may contain the department organizational unit objects associated with each department in the division. Finally, an organization container representing the corporation as a whole may contain the company's division organizational unit objects. Combining the use of policies and directory services facilitates management of groups of computers and users. Policies may be associated with the various containers in the directory services tree to store associated configuration information at the organization, division, or departmental level. For example, a policy may be associated with the Accounts Receivable container in a corporate organization to set options for the accounting program used in that department. Exceptions to the policy can be managed on an individual level, or by creating a group object and associating a policy with the group. Suppose, for example, that all employees in an organization use a software application with a particular set of configuration options, but department managers require a different set of options. A policy could be created with the basic set of options and associated with the organization container. A separate policy with the configuration options for managers could be created and assigned to a Managers user group object. Using policies and directory services in combination has proven efficient in homogeneous operating system environments. Prior art computer management systems use policies targeted toward a specific operating system, referred to as the native operating system. From the point of view of prior art policy and policy management systems, other operating systems are considered to be foreign operating systems. However, the operating requirements of many organizations require information technology managers to manage multiple operating systems. The efficiencies associated with policies and directory services have not been realized in heterogeneous operating system environments. Since different operating systems use different approaches to setting configuration information, a policy associated with a directory services container may be applied to users of a native operating system that provided the policies, but there may not be a method for applying the policy for users of a foreign operating system. From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that extend the use of policies to manage configuration information on computers having operating systems that are foreign to the policy creation and management environment. Beneficially, such an apparatus, system, and method would control cost and complexity associated with management of computers with heterogeneous operating systems within an organization. The benefits are multiplied when network directory services are used in conjunction with policies. SUMMARY OF THE INVENTION The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available policy management systems. Accordingly, the present invention provides an apparatus, system, and method for managing policies on a computer having a foreign operating system that overcome many or all of the above-discussed shortcomings in the art. In one aspect of the present invention, a method for managing policies on a computer having a foreign operating system includes providing a policy on a first computer with a native operating system, receiving the policy on a second computer with a foreign operating system, and translating the policy to configuration information usable on the second computer. In one embodiment, the method includes receiving the policy on the second computer at workstation start-up. The method also may include updating the policy at user login. These embodiments facilitate obtaining the current policy at the time they are typically needed by operating systems. In further embodiments, the method includes polling the first computer at periodic intervals for changes to the policy. In these embodiments, configuration information usable on the second computer are updated to reflect changes in policy on the first computer, to keep the configuration information and policy closely synchronized. The method may also con include applying configuration information associated with directory services containers and objects. For example, a policy associated with a directory services organization container may be translated to configuration information that may then be applied to all users in the organization container. In another aspect of the present invention, an apparatus to manage policies on a computer having a foreign operating system includes a policy on a first computer having a native operating system, a policy translator that translates the policy to configuration information usable on a second computer having foreign operating system, and a translator manager that manages the association between the policy on the first computer and the translator on the second computer. The apparatus, in one embodiment, is configured to manage configuration information usable on a second computer having a foreign operating system by means of policies on a first computer having a native operating system. A translator manager manages the association between the policy on the first computer, and a policy translator on the second computer. The apparatus is further configured, in one embodiment, to include policies associated with network directory services containers and objects. Policies may be associated, for example, with organization containers, organizational unit containers, and user objects, facilitating the configuration of hardware or software information for groups of computer users at a corporate, department, or individual level. Various elements of the present invention may be combined into a system arranged to carry out the functions or steps presented above. In one embodiment, the system includes two computers, the first having a native operating system and the second having a foreign operating system. In particular, the system, in one embodiment, includes a directory services server and database, a communications network, a policy, a policy editor, a policy template, a translator manager, and a policy translator. Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: FIG. 1 is a schematic block diagram depicting one embodiment of a typical prior art networking environment wherein the present invention may be deployed; FIG. 2 is a schematic block diagram illustrating one embodiment of a prior art policy management apparatus; FIG. 3 is a schematic block diagram illustrating one embodiment of a policy management system in accordance with the present invention; FIG. 4 is a schematic block diagram illustrating another embodiment of a policy management system in accordance with the present invention; FIG. 5 is a schematic flow chart diagram illustrating one embodiment of a provide translator method in accordance with the present invention; FIG. 6 is a schematic flow chart diagram illustrating one embodiment of a policy translation method in accordance with the present invention; and FIG. 7 is a text diagram illustrating one embodiment of policy translation example data in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module. Indeed, a module of executable code could be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. FIG. 1 depicts one embodiment of a typical prior art networking environment 100 that demonstrates the issues regarding managing currently deployed enterprises. As depicted, the networking environment 100 includes one or more servers 110, a network 120, and one or more networked computers 130. The components of the networking environment 100 may reside at a single site or may be dispersed over multiple sites. Some of the servers 110 may be directory servers or domain servers which can function as a registry for resources and users of the networking environment 100. The network 120 may include routers, bridges, hubs, gateways, or the like which facilitate communications among the components of the networking environment 100. Some of the networked computers 130 may execute legacy applications and operating systems that are unable to integrate with the servers 110 that are directory servers. Some of the networked computers 130 may be used to run utility applications to manage the servers 110 that are directory servers and features of the directory service that runs on the servers 110. These networked computers 130 that manage the directory service typically do not include functionality to manage foreign operating systems that may run on other networked computers 130. FIG. 2 is a schematic block diagram illustrating one embodiment of a prior art policy management apparatus 200. The prior art policy management apparatus 200 includes a policy template 210, a policy editor 220, a first computer 260 having a native operating system, and a second computer 270 having the same native operating system. The first computer 260 includes a policy manager 230a, a policy-related file 240, and a configuration information database 250a. The second computer 270 includes a policy manager 230b, and a configuration information database 250b. This apparatus is configured to efficiently manage a group of computers having like operating systems. An administrative user may use a policy template 210 and a policy editor 220 to control the operation of the policy manager 230a. The policy template 210 and the policy editor 220 may be located on the first computer 260 or may be on another computer. The policy manager 230a may use a policy-related file 240 and settings (i.e. information) in a configuration information database 250a to record the policy settings created by the administrative user. As a means for efficiently managing a group of computers with like operating systems, a policy manager 230b in a second computer 270 may be configured to obtain policy settings by reading from the policy-related file 240 or the configuration information con database 250a on the first computer 260, as represented by the dashed lines 233 and 236 in FIG. 2. The policy manager 230b may then make settings to the configuration information database 250b on the second computer 270. The policy may include configuration information that applies specifically to the second computer 270, or to a specific user or any of a group of users of the second computer 270. Configuration information may be associated with network directory services containers and objects. For example, by associating configuration information with an organizational unit container, the behavior of an application can be controlled for all users in a company department. Configuration information maybe assigned to containers and objects at various levels in a directory services hierarchy, facilitating management of hardware and software configuration information at various organizational, geographical, or individual levels. For example, application configuration information may be associated with an organization container, organizational unit container, and user object in a network directory services hierarchy, resulting in application configuration options being assigned at corporate, departmental, and individual levels in an organization. FIG. 3 is a schematic block diagram illustrating one embodiment of a policy management system 300 in accordance with the present invention. The depicted policy management system 300 includes a network 310, a first computer 320, and a second computer 340. The first computer 320 includes a policy template 322, a policy editor 324, a policy manager 230, a policy-related file 326, and a configuration information database 250. The depicted second computer 340 includes a translator manager 342, a translator 344, and a policy-related file 346. The policy management system 300 facilitates management of a group of computers with multiple operating systems by using the first computer 320 as a reference computer from which configuration information are replicated to other computers in a workgroup, or the like. The policy management system 300 depicted in FIG. 3 represents a peer-oriented embodiment of the present invention, where the first computer 320 and the second computer 340 are workstations, and no server is required. An administrative user may use a policy template 322 and policy editor 324 to control the operation of the policy manager 230. The policy manager 230 may use a policy-related file 326 and settings or information in a configuration information database 250 to record the policy settings created by the administrative user. The translation manager 342 in the second computer 340 may be configured to obtain policy settings by reading from the policy-related file 326 and the configuration information database 250 on the first computer 320, as represented by the dashed lines 333 and 336 in FIG. 3. The translation manager 342 then passes the policy settings obtained from the first computer 320 to the translator 344 to translate to configuration information that may be stored in a policy-related file 346 on the second computer 340. In some embodiments, the translator 344 modifies configuration information stored in a plurality of files. The policy-related file 346 may not be exclusively dedicated to storing policy information. For example, the policy-related file 346 may contain non-policy data or code. In some embodiments, the operating system on the first computer 320 may provide an event notification system that notifies the translation manager 342 that changes have been made to the policy-related file 326 or the configuration information database 250. FIG. 4 is schematic block diagram illustrating another embodiment of a policy management system 400 in accordance with the present invention. The policy management system 400 includes a server 410, network 310, a first computer 320, and a second computer 340. The server 410 includes a policy-related file 413, and a configuration information database 416. The first computer 320 includes a policy template 322, a policy editor 324, and a policy manager 230. The second computer 340 includes a translation manager 342, a translator 344, and a policy-related file 346. The policy management system 400 facilitates management of a group of computers having multiple operating systems by replicating configuration information from a server 410, such as a directory server. The policy management system 400 depicted in FIG. 4 represents a client-server-oriented embodiment of the present invention, where configuration information are stored on a server 410 and replicated to client workstations represented by the second computer 340. As with the embodiment depicted in FIG. 3, an administrative user may use a policy template 322 and policy editor 324 to control the operation of the policy manager 230. In this embodiment, however, the policy manager 230 may use a policy-related file 413 and settings in a configuration information database 416 to record the policy settings created by the administrative user on a server 410. The translation manager 342 in the second computer 340 may be configured to obtain policy settings by reading from the policy-related file 413 and the configuration information database 416 on the server 410, as represented by the dashed lines 433 and 436 in FIG. 4. The translation manager 342 then passes the policy settings obtained from the first computer 320 to the translator 344 to translate to configuration information that may be stored in a policy-related file 346 on the second computer 340. The following schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps, methods, and orderings may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. FIG. 5 is a schematic flow chart diagram illustrating one embodiment of a provide translator method 500 in accordance with the present invention. The provide translator method 500 includes a provide policy template step 520, and a provide policy translator step 530. The provide translator method 500 provides modules that facilitate translation of policy settings from a native operating system to a foreign operating system. The provide policy template step 520 provides a policy template such as the policy template 322 to be used in conjunction with the policy editor 324, or the like. As detailed in FIG. 3 and elsewhere, the policy template 322 constrains policy editing, such that policies created by the policy editor 324 conform to requirements of the first computer 320. For example, the policy template 322 may ensure that configuration information car delivered to the policy manager 230 conform to a required syntax, or that numerical values fall within a meaningful range. The provide policy template step 520 may provide a plug-in module to an operating system utility program. In some embodiments, the provide policy template step 520 provides a wizard program module that guides a user through the process of creating a policy. The provide policy translator step 530 provides a translator 344 that translates configuration information from the first computer 320 having a native operating system to the second computer 340 having a foreign operating system. The provide policy translator step 530 may place the translator 344 in a file system directory known to the translator manager 342. In some embodiments, the provide policy translator step 530 may register the file system location of the translator 344 with the translator manager 342. Upon completion of the provide policy translator step 530, the provide translator method 500 ends 540. FIG. 6 is a schematic flow chart diagram illustrating one embodiment of a policy translation method 600 in accordance with the present invention. The policy translation method 600 includes a provide policy step 620, a receive policy step 630, a translate policy step 640, an update configuration step 650, an update on start-up test 655, a wait for start-up step 660, an update on login test 665, a wait for login step 670, a refresh time test 675, and a terminate test 685. The policy translation method 600 translates policies on a first computer 320 having a native operating system to policies for a second computer 340 having a foreign operating system. The provide policy step 620 provides a policy on the first computer 320 having a native operating system. The provide policy step 620 may be performed by an administrative user using a policy template 322, policy editor 324, and/or policy manager 230. The policy may be contained in a policy-related file 326 and a configuration information database 250 on the first computer 320. In some embodiments, the policy may be contained in a policy-related file 413 and a configuration information database 416 on a server 410, such as a directory server. The receive policy step 630 receives the policy on the second computer 340 having a foreign operating system. The receive policy step 630 may be performed by a translator manager 342 on the second computer 340. The translator manager 342 may copy the policy from a policy-related file 326 and a configuration information database 250 on the first computer 320. In other embodiments, the translator manager 342 may copy the policy from a policy-related file 413 and a configuration information database 416 on a server 410, such as a directory server. The translator manager 342 transmits the policy to a translator 344. The translate policy step 640 translates configuration information from the first computer 320 having a native operating system to the second computer 340 having a foreign operating system. The translate policy step 740 may be performed by a translator 344 on the second computer 340. The translator 344 receives the policy from the translator manager 342 and translates the policy to foreign operating system configuration information used by the second computer 340. The update configuration step 650 applies the configuration information translated by the translator 344. The update configuration step 650 may be performed by a translator 344 on the second computer 340 having a foreign operating system. After translating the policy to foreign operating system configuration information, the translator 344 applies the policy by saving the configuration information in a policy-related file 346. In some embodiments, configuration information may be saved in a plurality of policy-related files 346. The update on start-up test 655 determines whether the policy is to be applied at workstation start-up. A policy may contain configuration information for all users of the second computer 340. Many operating systems apply configuration information at workstation start-up. Updating configuration information on the second computer 340 during workstation start-up makes the updated settings available for application during the workstation start-up process. If the policy is to be updated at workstation start-up, the policy translation method 600 continues with the wait for start-up step 660, otherwise the policy translation method 600 continues with the update on login test 665. The wait for start-up step 660 waits for the second computer 340 to reach a point in the workstation start-up process where computer resources are available for the second computer 340 to receive the policy from the first computer 320. The wait for start-up step 660 includes setting a configuration setting that causes the policy translation method 600 to continue with the receive policy step 630 at workstation start-up. The wait for start-up step 660 facilitates receiving the current version of the policy so that configuration information may be applied to the second computer 340 at workstation start-up, when many operating systems typically read configuration information. Updating a policy at workstation start-up is particularly advantageous to workstation-specific configuration information. The update on login test 665 determines whether the policy is to be applied at user login. A policy may contain configuration information that applies to a specific user or any of a group of users of the second computer 340. In some embodiments, configuration information may be associated with network directory services containers and objects. For example, by associating configuration information with an organizational unit container, the behavior of an application can be controlled for all users in a company department. Updating configuration information on the second computer 340 makes the current version of the settings available for application for the user logging in. If the policy is to be updated at user login, the policy translation method 600 continues with the wait for login method 670, otherwise the policy translation method 600 continues with the refresh time test 675. The wait for login step 670 waits for a user to log in to the second computer 340 to receive the policy from the first computer 320. The wait for login step 670 includes setting a configuration setting that causes the policy translation method 700 to continue with the receive policy step 630 at user login. The wait for login step 670 facilitates receiving the current version of the policy so that configuration information may be applied to the second computer 340 at user login, when many operating systems typically read configuration information. Updating a policy at user login is particularly advantageous to user-specific configuration information. The refresh time test 675 determines whether it is time to check for updates to the policy on the first computer 320. In some embodiments, the refresh time test 675 polls the first computer 320 at periodic intervals for changes to the policy. The polling interval may be configurable by the user or may itself be a setting configurable by a policy. In some embodiments, the refresh time test 675 may include a means for the first computer 320 to notify the second computer 340 that a change has been made to the policy, and that the policy should be refreshed on the second computer 340. If the refresh time has arrived, the policy translation method 600 continues with the receive policy step 630, otherwise it continues with the terminate test 685. The terminate test 685 determines whether the refresh time test 675 should be repeated, or if the policy translation method 600 should terminate. In some embodiments, the policy translation method 600 may be terminated to facilitate deallocation of memory or other computer resources when the second computer 340 is shut down, or to allow for system maintenance. If the policy translation method is not to be terminated, it continues with the refresh time test 675, other wise it ends 690. FIG. 7 is a text diagram illustrating one embodiment of policy translation example data in accordance with the present invention. The policy translation example data 700 includes policy template data 710, policy manager input data 720, native policy-related file data 730, and translated policy-related file data 740. The policy translation example data may be generated in accordance with the policy translation method 600 and the policy management system 300. The policy template data 710 is one example of the policy template 322. The policy template 322 may reside on the first computer 320 having a native operating system or on a third computer, such as an administrative workstation. The policy template data 710 may comprise plain ASCII text used to constrain data input accepted by the policy editor 324 by identifying names of data objects that the policy editor 324 will allow the user to edit. Policy template data 710 may also contain the text of prompts or other fields that control the user interface presented by the policy editor 324. Using the policy template 322, the policy editor 324 may accept input from an administrative user and generate input data for the policy manager 230. Policy manager input data 720 illustrates the format of data that may be generated by the policy editor 324. In various embodiments, in accordance with the provide policy step 620, the policy manager 230 may accept the policy manager input data 720 from a file created by the policy editor 324, from a file created by an administrative user, or communicated directly from the policy editor 324 to the policy manager 230 via interprocess communication. The policy manager 230 may alter the format or contents of the policy manager input data 720. In some embodiments, the policy manager creates a policy-related file 326 and enters the location of the policy-related file 326 in the configuration settings database 250. The native policy-related file data 730 is a textual representation of binary data in one embodiment of the policy-related file 326. The native policy-related file data 730 is generated by the policy manager 230, and in preparation for the receive policy step 630, is stored in a format and location typically used with the native operating system in use on the first computer 320. In the depicted embodiment, the native policy-related file data 730 comprises mixed binary and UNICODE text delimited by square brackets. The translated policy-related file data 740 is one example of the policy-related file 346. In accordance with the translate policy step 640, the translator 344 translates the policy data received from the translator manager 342 to data usable by the foreign operating system used by the second computer 340. The depicted translated policy-related file data 740 is one example of a configuration file that a translator 344 has converted from mixed binary and UNICODE format to plain ASCII text format, and filtered to include only data usable by the foreign operating system in use on the second computer 340. In the depicted example, the translated policy-related file data 740 comprises a list of user names that will be allowed to log in to the second computer 340. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates to managing groups of computers and more particularly relates to managing policies for configuring hardware or software settings on groups of computers with a plurality of operating systems. 2. Description of the Related Art A major concern of information technology management in corporations and other organizations has been balancing the complexity associated with managing large numbers of computers with the needs of individual users as they try to accomplish their tasks. A heterogeneous set of computer hardware, operating systems, and application software creates complexity and increased costs, but various combinations of hardware, operating systems, and software provide technical advantages when used as user workstations, departmental servers, corporate infrastructure equipment, and the like. User workstations are particularly difficult to manage when various needs and preferences of individual users are accommodated. For example, an engineer may require the use of a CAD system that runs only on the UNIX™ operating system, where other corporate users may be standardized on the Microsoft Windows™ operating system and associated applications. Many similar compatibility issues exists among current computer systems. One factor that adds to the complexity of managing various operating systems is that different operating systems employ different techniques for setting configuration information. For example, Microsoft Windows™ and applications that run on Windows typically use a database, called the registry, to store configuration information. Computers running the UNIX operating system or derivatives thereof such as LINUX typically store configuration information in plain text files in particular locations in the file system directory. Information technology managers within an organization that uses heterogeneous operating systems typically institute separate sets of management procedures and standards for each operating system used in the organization. One component of prior art solutions to the problem of managing large numbers of computers and users is the use of policies. Policies are used to set configurable options associated with an operating system or application program for a group of computer users. For example, a word processing program may have an option to select an American English dictionary or a British English dictionary. By creating one policy for its users in the United States and another policy for its users in England, an organization can set the appropriate option for all users without configuring each user's computer individually. Another component of prior art solutions to the problem of managing groups of computers and users is the use of network directory services. Directory services provide an infrastructure to store and access information about network-based entities, such as applications, files, printers, and people. Directory services provide a consistent way to name, describe, locate access, manage, and secure information about these resources. The directories associated with directory services are typically hierarchical structures such as a tree with each node in the hierarchy capable of storing information in a unit often referred to as a container. Enterprises may use directory servers and directory services to centrally manage data that is accessed from geographically dispersed locations. For example, corporations typically create network directory trees that mirror their corporate organizations. Information about individual employees, such as their employee number, telephone number, and hire date may be stored in a user object corresponding to each user in the directory tree. An organizational unit container representing each department may contain the user objects associated with each employee in the department. Organizational unit objects associated with each corporate division may contain the department organizational unit objects associated with each department in the division. Finally, an organization container representing the corporation as a whole may contain the company's division organizational unit objects. Combining the use of policies and directory services facilitates management of groups of computers and users. Policies may be associated with the various containers in the directory services tree to store associated configuration information at the organization, division, or departmental level. For example, a policy may be associated with the Accounts Receivable container in a corporate organization to set options for the accounting program used in that department. Exceptions to the policy can be managed on an individual level, or by creating a group object and associating a policy with the group. Suppose, for example, that all employees in an organization use a software application with a particular set of configuration options, but department managers require a different set of options. A policy could be created with the basic set of options and associated with the organization container. A separate policy with the configuration options for managers could be created and assigned to a Managers user group object. Using policies and directory services in combination has proven efficient in homogeneous operating system environments. Prior art computer management systems use policies targeted toward a specific operating system, referred to as the native operating system. From the point of view of prior art policy and policy management systems, other operating systems are considered to be foreign operating systems. However, the operating requirements of many organizations require information technology managers to manage multiple operating systems. The efficiencies associated with policies and directory services have not been realized in heterogeneous operating system environments. Since different operating systems use different approaches to setting configuration information, a policy associated with a directory services container may be applied to users of a native operating system that provided the policies, but there may not be a method for applying the policy for users of a foreign operating system. From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that extend the use of policies to manage configuration information on computers having operating systems that are foreign to the policy creation and management environment. Beneficially, such an apparatus, system, and method would control cost and complexity associated with management of computers with heterogeneous operating systems within an organization. The benefits are multiplied when network directory services are used in conjunction with policies. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available policy management systems. Accordingly, the present invention provides an apparatus, system, and method for managing policies on a computer having a foreign operating system that overcome many or all of the above-discussed shortcomings in the art. In one aspect of the present invention, a method for managing policies on a computer having a foreign operating system includes providing a policy on a first computer with a native operating system, receiving the policy on a second computer with a foreign operating system, and translating the policy to configuration information usable on the second computer. In one embodiment, the method includes receiving the policy on the second computer at workstation start-up. The method also may include updating the policy at user login. These embodiments facilitate obtaining the current policy at the time they are typically needed by operating systems. In further embodiments, the method includes polling the first computer at periodic intervals for changes to the policy. In these embodiments, configuration information usable on the second computer are updated to reflect changes in policy on the first computer, to keep the configuration information and policy closely synchronized. The method may also con include applying configuration information associated with directory services containers and objects. For example, a policy associated with a directory services organization container may be translated to configuration information that may then be applied to all users in the organization container. In another aspect of the present invention, an apparatus to manage policies on a computer having a foreign operating system includes a policy on a first computer having a native operating system, a policy translator that translates the policy to configuration information usable on a second computer having foreign operating system, and a translator manager that manages the association between the policy on the first computer and the translator on the second computer. The apparatus, in one embodiment, is configured to manage configuration information usable on a second computer having a foreign operating system by means of policies on a first computer having a native operating system. A translator manager manages the association between the policy on the first computer, and a policy translator on the second computer. The apparatus is further configured, in one embodiment, to include policies associated with network directory services containers and objects. Policies may be associated, for example, with organization containers, organizational unit containers, and user objects, facilitating the configuration of hardware or software information for groups of computer users at a corporate, department, or individual level. Various elements of the present invention may be combined into a system arranged to carry out the functions or steps presented above. In one embodiment, the system includes two computers, the first having a native operating system and the second having a foreign operating system. In particular, the system, in one embodiment, includes a directory services server and database, a communications network, a policy, a policy editor, a policy template, a translator manager, and a policy translator. Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. | 20040709 | 20091110 | 20060112 | 96612.0 | G06F946 | 1 | HO, ANDY | APPARATUS, SYSTEM, AND METHOD FOR MANAGING POLICIES ON A COMPUTER HAVING A FOREIGN OPERATING SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | G06F | 2,004 |
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10,888,937 | ACCEPTED | Load binder | A load binder for use in connection with a typical tie strap for securing a load for transport is provided. The load binder includes elements that are conformable to the shape of a particular load and which prevent the tie down from twisting upon itself. The load binder essentially comprises a body having and a handle pivotally attached to the body, a link pivotally attached to the handle, a first tie down engaging element attached to the link by a ball joint and a second tie down engaging element attached to the threaded shaft by a ball joint. The freely movable ball joints coupling the tie engaging elements to the binder allow the binder to conform to the shape of the load and also prevent the tie down from twisting upon itself. Additionally, a safety latch is incorporated into the binder which positively locks the handle in position relative to the body. | 1. A load binder for use in conjunction with a load securing tie down for securing a load for transport, comprising: a body having a first end and a second end, wherein said first end is bifurcated and wherein said second end defines an axial bore having a threaded end section; a handle having a first end and a second end, wherein said first end of said handle is bifurcated and is received between the furcations of said first end of said body so that the furcations of said first end of said body are juxtaposed the furcations of said first end of said handle, further wherein the juxtaposed furcations are pinned to each other so that said handle and said body are pivotally connected at said first end of said body and at said first end of said handle; a link having a first end which is pinned to said handle approximate said first end of said handle and a second free end; a threaded shaft received by said threaded bore of said second end of said body; a first tie engaging element; a first ball joint coupling said first tie engaging element to said free end of said a second tie engaging element; a second ball joint coupling said first engaging element to said threaded shaft; and a safety pin wherein said safety pin is received by cooperating holes defined by the furcations of said first end of said body and the furcations of said first end of said handle such that that said safety pin passes completely through said body and completely through said handle and is positioned outwardly of said links thereby preventing said link from rotating in a direction outwardly from the load. 2. (canceled) 3. The load binder of claim 1, wherein said safety pin comprises: a clasp having a first end fixedly attached to a first end of said safety pin and a second end detachably secured to a second end of said safety pin. 4. The load binder of claim 1, wherein said first end of said handle is triangular shaped and further wherein said link is fixedly pinned to an apex of thereof. 5. The load binder of claim 1, further comprising a stop means for retaining a predetermined length of said thread shaft within said axial bore, said stop means is incorporated into said threaded shaft and said axial bore. 6. The load binder of claim 5, wherein said predetermined length is at least about equal to twice the diameter of said threaded shaft. 7. The load binder of claim 1, wherein said handle defines a slot for receiving a safety strap used to secure the relative position of said handle to said body. 8. The load binder of claim 1, wherein said first and said second ball joints are free to rotate to prevent said tie down from becoming twisted upon itself. 9. (canceled) 10. A load binder for use in conjunction with a load securing tie down for securing a load for transport, comprising: a body having a first end and a second end, wherein said first end is bifurcated and wherein said second end defines an axial bore having a threaded end section; a handle having a first end and a second end, wherein said first end of said handle is bifurcated and is received between the furcations of said first end of said body so that the furcations of said first end of said body are juxtaposed the furcations of said first end of said handle, further wherein the juxtaposed furcations are pinned to each other so that said handle and said body are pivotally connected at said first end of said body and at said first end of said handle; a link having a first end and an free end, said first end is fixedly pinned to said handle approximate said first end of said handle and between said furcations of said first end of said handle, said link is free to pivot between said furcations of said first end of said body and said furcations of said first end of said handle; a threaded shaft received by said threaded bore of said second end of said body; a first tie engaging element; a first ball joint coupling said first tie engaging element to said link; a second tie engaging element; a second ball joint coupling said first engaging element to said threaded shaft; a safety pin, wherein said safety pin is received by cooperating holes defined by the furcations of said first end of said body and the furcations of said first end of said handle such that that said safety pin passes completely through said body and completely through said handle and is positioned outwardly of said link, thereby preventing said link from rotating in a direction outwardly from the load; and wherein said handle defines a slot for receiving a safety strap used to secure the relative position of said handle to said body and said handle rotating relative to said body. 11. The load binder of claim 10, wherein said first end of said handle is triangular shaped and further wherein said link is pinned to an apex of thereof. 12. (canceled) 13. The load binder of claim 10, wherein said safety pin comprises: a clasp having a first end fixedly attached to a first end of said safety pin and a second end detachably secured to a second end of said safety pin. 14. The load binder of claim 10, further comprising a stop means for retaining a predetermined length of said thread shaft within said axial bore, said stop means is incorporated into said threaded shaft and said axial bore. 15. The load binder of claim 14, wherein said predetermined length is at least about equal to twice the diameter of said threaded shaft. 16-18. (canceled) 19. A load binder for use in conjunction with a load securing tie down for securing a load for transport, comprising: a body having a first end and a second end, wherein said first end is bifurcated and wherein said second end defines an axial bore having a threaded end section; a handle having a first end and a second end, wherein said first end of said handle is bifurcated and triangular shaped and is received between the furcations of said first end of said body so that the furcations of said first end of said body are juxtaposed the furcations of said first end of said handle, further wherein the juxtaposed furcations are pinned to each other so that said handle and said body are pivotally connected at said first end of said body and at said first end of said handle; a link having a first end and an free end, said first end is fixedly pinned to an apex of said handle approximate said first end of said handle and between said furcations of said first end of said handle, said link is free to pivot between said furcations of said first end of said body and said furcations of said first end of said handle; a threaded shaft received by said threaded bore of said second end of said body; a first tie engaging element; a first ball joint coupling said first tie engaging element to said link; a second tie engaging element; a second ball joint coupling said first engaging element to said threaded shaft, a safety pin, wherein said safety pin is received by cooperating holes defined by the furcations of said first end of said body and the furcations of said first end of said handle such that that said safety pin passes completely through said body and completely through said handle and is positioned outwardly of said link, thereby preventing said link from rotating in a direction outwardly from the load; a clasp having a fist end fixedly attached to a first end of said safety pin and a second end detachably secured to a second end of said safety pin; a stop means for retaining a predetermined length of said thread shaft within said axial bore, said stop means is incorporated into said threaded shaft and said axial bore; and wherein said handle defines a slot for receiving a safety strap used to secure the relative position of said handle to said body. | BACKGROUND OF THE INVENTION Field of the Invention The present invention relates generally to load binders for tensioning tie downs used to secure a load of cargo for transportation. More particularly, relating to a load binder having elements that are conformable to the shape of a particular load and which includes an improved tension adjustment assembly and safety lock. SUMMARY OF THE INVENTION In accordance with the present invention, an improved load binder is provided for tensioning a tie down and which is conformable to the shape of the load being secured by the tie down and which also reduces twisting of the tie down. One of the main improvements of the load binder of the present invention is found in the use of flexible joints for attaching tie down engaging elements to the load binder so that the load binder is able to conform to the general cross sectional shape of the load being secured by the tie downs. Heretofore, load binders have been rigid machines that did not include elements allowing the load binder to generally conform to the shape of the cargo being secured by the tie down without putting undue bending strain and stress on the load binder. Load binders are designed to take large axial loading which is required to provide a large amount of tension in the tie downs to properly secure a load being transported. However, load binders quite frequently experience large bending moments created by tensioning a tie down around a curvilinear load, such as large diameter pipes quite frequently used in drainage systems, large stacks of smaller diameter pipes, stacks of timber and the like. There is a high frequency of failure in prior art load binders when used in securing loads of this type, which results in injury to operators or pedestrians and damage to the load. As such, the load binder of the present invention is conformable to the cross sectional shape of the load being secured to prevent failure of the load binder due bending stress, thereby increasing the safety of the operator, safety of pedestrians and safety of the load being transported. In doing so, the load binder essentially comprises a body having a bifurcated first end and an elongated second end that defines an axial bore which includes a threaded portion, a handle having a bifurcated first end which is received by the bifurcated end of the body and which is pivotally attached therewith by a pair of pins, one each coupling the juxtaposed furcations of the bifurcated first end of the body and the bifurcated first end of the handle, a threaded shaft threadably received by the second end of the body, a link pivotally attached to the first end of the handle, a first tie down engaging element attached to the link by a ball joint, a second tie down engaging element attached to the threaded shaft by a ball joint and a safety pin. An additional advantage of the instant load binder is the ability of the load binder to reduce twisting of the a tie down during the tensioning thereof, which will be described in further detail infra. There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: FIG. 1 is a side elevation view of the preferred embodiment of the load binder in use securing a tie down about a stack of pipes; FIG. 2 is a side elevation view of the load binder illustrating the binder in a generally non-clamped position; FIG. 3 is an enlarged partial top plan view of the load binder in a clamped, loaded position; FIG. 4 is a cross sectional view taken along line 4-4 in FIG. 3; and FIG. 5 is a partial cross sectional view of the second end of the body of the load binder. The same reference numerals refer to the same parts throughout the various figures. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, and particularly to FIGS. 1-5 a preferred embodiment of the load binder of the present invention is shown and generally designated by the reference numeral 10. In FIG. 1, a new and improved load binder 10 of the present invention for tensioning a typical tie down 100 to secure a typical load 110 is illustrated and will be described. More particularly, the load binder 10 is comprised of a body 12, a handle 14 pivotally connected to the body at point 16, a threaded shaft 18, a link 20, which is pivotally connected to the handle 14, a first tie down engaging element 22 connect to the link by a ball joint 24, a second tie down engaging element 26 connected to the threaded shaft by a ball joint 28 at point 30 and a safety pin 32. The load binder 10 is illustrated in an in-use configuration where the handle 10 is closed against the body 12 to remove slack in the tie down 100 to secure the load 110. For exemplary purposes only, the load 110 is illustrated as a stack of small diameter pipes having a curvilinear cross sectional shape. The view illustrates how the load binder can conform to the shape of the load, where each ball joint 16 and 28 are slightly rotated downward towards the load so that the tie engaging elements 22 and 26 can partially wrap around the load to engage the ends of the tie down 100, while transferring the majority of tension force present within the tie down axially along the load binder to reduce bending stress thereof. Prior art load binders do not have the provision of the ball joint coupling elements 16 and 28 for attaching tie engaging elements 22 and 26 to the load binder 10. While most prior art load binders make use of a typical chain link or D-ring connection between the tie engaging elements and the load binder allowing the tie engaging element to pivot in a single plane in space to slightly conform to a load, this arrange creates a sharp angle change along the tension force path which results in a high bending moment in the load binder. In addition, the methods of attaching the tie engagement elements of prior art load binders with the binder does not allow for the tie engagement elements to rotate freely about an axis parallel to the tie engaging elements. This quite frequently results in a tie down twisting upon its self as tension is applied by during the actuation of the load binder. This creates a major point of failure with the integrity of the securment of the load, in that during transport the load may shift resulting in the tie becoming untwisted causing the tie to lose tension and to not properly secure load, which can result in the load becoming free during transportation. The inclusion of the ball joints 16 and 28 in the preferred embodiment for attaching the tie engaging elements 22 and 26 to the load binder 10 insures the tie will not twist upon itself during tensioning thereof. Now turning to FIGS. 2 and 3, in FIG. 2 the load binder 10 is illustrated in a non-clamped position with the handle 14 rotated away from the body 12 and in FIG. 3, which is an enlarged detailed top view, the load binder shown in a generally closed position. The body 12 includes a bifurcated first end 34 having two parallel furcations 38 and an elongated second end 36, which is adapted to threadably receive the threaded shaft 18. The handle 14 has a bifurcated first end 40 having two parallel furcations 42 which are positioned between the furcations 38 of the first end 34 of the body 12, as illustrated. Each pair of juxtaposed furcations 38 and 42 are pinned to each other by a pair pins 44a and 44b. The use of two separate pins 44a and 44b allows the space between the furcations 42 to remain open so as to receive the link 20 therebetween. A first end 46 of the link 20 is pivotally connected to the handle between the furcations 42 by a link pin 47. The free end 48 of the link 20 is free to pivot between the furcations 38 of body 12 and the furcations 42 of the handle 14. Ball joint 24 is connected between the end 48 of the link 20 and the tie engaging element 22, and ball joint 28 is connected between end 50 of the threaded shaft 18 and the tie engaging element 26. Preferably, the first end 40 of the handle is triangular shaped with the first end 46 of the link 10 pinned at apex 52 by the link pin 46. The triangular shaped end 40 of the handle 14 with the link 10 pinned at apex 52 provides a cam action between the handle 14 and the body 12 when the handle is rotated where the center line parallel to the tension force along link 10 of the apex passes a corresponding parallel center line of the pinned connections between furcations 38 and 42. Most preferably, the handle 14 is elongated and is of a length that is greater then the length of the body 12 to provide a force advantage to an operator aiding the operation of the load binder 10. Turning now to FIG. 4, which is an enlarged cross sectional view of the load binder 10 taken along line 4-4 in FIG. 3. The load binder 10 can also include a safety pin 56 that is passed through cooperating holes 57 formed through each furcation 38 of the end 34 and through each furcation 42 of end 40. The safety pin 56 provides an additional security feature to the load binder 10 by locking the relative position of the handle 14 with the body 12 ensuring the handle will not pop lose when loaded and securing a tie down. Most preferably, a clasp 58 is provided and is fixedly attached to the safety pin 56 at one and removably attached to the safety pin at an opposite end. Most preferably, the clasp 58 is attached to the ends of the safety pin 56 beyond the outer surfaces of the furcations 38 and wraps around the furcations 38 and 42 from one end of the safety pin to the opposite end of the safety pin. While the preferred safety pin 56 is describe supra it is recognized other elements or different types of pins could reasonable be substituted for the safety pin 56 as preferably described. Examples of different types of elements that could be substituted for safety pin 56 includes but is not limited to a padlock or a D-ring or the like. Examples of different types of pins that could be substituted includes but is not limited to a cotter pin, a roll pin, a clevis pin, a hitch pin or a snap pin. Referring now to FIG. 5, which a partial longitudinal cross section view of the second end 36 of the body 12 and of the threaded shaft 18. The second end 36 defines an axial bore 59 which includes a threaded section 60 to which the threaded shaft 18 is threaded into. The threaded shaft 18 can be threaded into and out of the axial bore 58 to a predetermined length to adjust the over-all length of the load binder 10. By turning the threaded shaft 18 in or out of the axial bore 59, the length of the load binder 10 can be finely adjusted to provide a desired amount of tension in the tie down. Additionally, a stop means 62 can be incorporated into the end 36 and the threaded shaft 18 to prevent the threaded shaft from being completely removed from the axial bore 59 and to retain a predetermined, desired length of the threaded shaft within the axial bore. An example of stop means 62 includes the threaded shaft 18 having a mushroomed head 63b and the axial bore 59 having a shoulder 63a that the head 63b abuts when the thread shaft is turned out a predetermined distance, thereby preventing the thread shaft from further removal from the axial bore. Preferably, the predetermined length is at least about twice the diameter of the threaded shaft 18. Most preferably, the predetermined length is at least one inch. In an additional embodiment, a slot 64 can be formed through the end 66 of the handle 14 opposite the bifurcated end 34. The slot 64 is adapted to receive a safety strap (not illustrated) threaded therethrough, which is secured around the second end 36 of the body to prevent the end 66 of the handle 14 from opening away from the second end 36 of the body. A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Field of the Invention The present invention relates generally to load binders for tensioning tie downs used to secure a load of cargo for transportation. More particularly, relating to a load binder having elements that are conformable to the shape of a particular load and which includes an improved tension adjustment assembly and safety lock. | <SOH> SUMMARY OF THE INVENTION <EOH>In accordance with the present invention, an improved load binder is provided for tensioning a tie down and which is conformable to the shape of the load being secured by the tie down and which also reduces twisting of the tie down. One of the main improvements of the load binder of the present invention is found in the use of flexible joints for attaching tie down engaging elements to the load binder so that the load binder is able to conform to the general cross sectional shape of the load being secured by the tie downs. Heretofore, load binders have been rigid machines that did not include elements allowing the load binder to generally conform to the shape of the cargo being secured by the tie down without putting undue bending strain and stress on the load binder. Load binders are designed to take large axial loading which is required to provide a large amount of tension in the tie downs to properly secure a load being transported. However, load binders quite frequently experience large bending moments created by tensioning a tie down around a curvilinear load, such as large diameter pipes quite frequently used in drainage systems, large stacks of smaller diameter pipes, stacks of timber and the like. There is a high frequency of failure in prior art load binders when used in securing loads of this type, which results in injury to operators or pedestrians and damage to the load. As such, the load binder of the present invention is conformable to the cross sectional shape of the load being secured to prevent failure of the load binder due bending stress, thereby increasing the safety of the operator, safety of pedestrians and safety of the load being transported. In doing so, the load binder essentially comprises a body having a bifurcated first end and an elongated second end that defines an axial bore which includes a threaded portion, a handle having a bifurcated first end which is received by the bifurcated end of the body and which is pivotally attached therewith by a pair of pins, one each coupling the juxtaposed furcations of the bifurcated first end of the body and the bifurcated first end of the handle, a threaded shaft threadably received by the second end of the body, a link pivotally attached to the first end of the handle, a first tie down engaging element attached to the link by a ball joint, a second tie down engaging element attached to the threaded shaft by a ball joint and a safety pin. An additional advantage of the instant load binder is the ability of the load binder to reduce twisting of the a tie down during the tensioning thereof, which will be described in further detail infra. There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention. | 20040712 | 20060627 | 20060112 | 63392.0 | B25B2500 | 1 | BRITTAIN, JAMES R | LOAD BINDER | UNDISCOUNTED | 0 | ACCEPTED | B25B | 2,004 |
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10,889,183 | ACCEPTED | Fixing apparatus and image forming apparatus that incorporates the fixing apparatus | A fixing apparatus includes a fixing member, a guiding member, and spacers. The fixing member is heated while rotating. The fixing member is in pressure contact with a recording medium that is advancing so that the developer deposited on the recording medium is fused. The guiding member extends across a path of the recording medium so that a predetermined amount of gap is defined between the guiding member and the fixing member. The guiding member guides the recording medium to separate from the fixing member. The spacers are disposed at longitudinal end portions of the guiding member outside of the path between the fixing member and the guiding member to define the predetermined amount of gap. The spacers are movable in a direction at an angle with a surface of the recording medium. The urging member urges the spacers against the fixing member. | 1. A fixing apparatus comprising: a fixing member, that is heated while rotating, said fixing member being in pressure contact with a recording medium that is advancing so that the developer deposited on the recording medium is fused; a guiding member extending across a path of the recording medium so that a predetermined amount of gap is defined between said guiding member and said fixing member, said guiding member guiding the recording medium to separate from said fixing member; spacers disposed at longitudinal end portions of said guiding member outside of the path, said spacers being between said fixing member and said guiding member to define the predetermined amount of gap, spacers being movable in directions at an angle with a surface of the recording medium; and an urging member that urges said spacers against said fixing member. 2. The fixing apparatus according to claim 1, wherein said fixing member rotates about a first axis and spacers are rotatable about a second axis substantially parallel to the first axis. 3. The fixing apparatus according to claim 2, wherein said spacers are rotatable about the second axis independently. 4. The fixing apparatus according to claim 3, wherein said guiding member is resilient. 5. The fixing apparatus according to claim 3, wherein said guiding member and said spacers are coupled in such a way that said guiding member is movable relative to said spacers. 6. The fixing apparatus according to claim 3, wherein said guiding member engages said spacers resiliently. 7. The fixing apparatus according to claim 1, further comprising an adjustment member that adjusts a positional relation between said guiding member and said spacers. 8. The fixing apparatus according to claim 3, wherein said guiding member is shaped to define a larger gap at the middle portion of said guiding member than at the longitudinal end portions of said guiding member. 9. The fixing apparatus according to claim 1, further comprising an inclination adjustment mechanism that adjusts an inclination of said guiding member relative to said fixing member. 10. The fixing apparatus according to claim 9, wherein said inclination adjustment mechanism operates to incline said guiding member while also maintaining the predetermined gap between said guiding and said fixing member. 11. A fixing apparatus comprising: a fixing member that is heated and is rotating about a first axis, said fixing member being in pressure contact with an advancing recording medium in such a way that the developer deposited on the recording medium is fused; a guiding member that defines a predetermined amount of gap between said guiding member and said fixing member, said guiding member guiding the recording medium to separate from said fixing member; spacers disposed at longitudinal end portions of said guiding member outside of the path, said spacers being disposed between said fixing member and said guiding member to define the predetermined amount of gap, wherein said spacers are rotatable independently about a second axis substantially parallel to the first axis so that said spacers are movable in directions at an angle with a surface of the recording medium; and an urging member that urges said spacers against said fixing member. 12. The fixing apparatus according to claim 11, further comprising an adjustment mechanism that adjusts a positional relation between said guiding member and said spacers. 13. The fixing apparatus according to claim 11, further comprising an inclination adjustment mechanism that adjusts an inclination of said guiding member relative to said fixing member. 14. The fixing apparatus according to claim 13, wherein said inclination adjustment mechanism operates to incline said guiding member while also maintaining the predetermined gap between said guiding and said fixing member. 15. An image forming apparatus incorporating the fixing apparatus according to claim 1, the apparatus further comprising: an image-forming section that forms an image with a developer on a recording medium. 16. An image forming apparatus incorporating the fixing apparatus according to claim 11, the apparatus further comprising: an image-forming section that forms an image with a developer on a recording medium. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a fixing apparatus and an image-forming apparatus that incorporates the fixing apparatus. 2. Description of the Related Art A conventional electrophotographic image-forming apparatus uses a fixing unit that includes upper and lower rollers and separators. The upper and lower rollers abut each other with a predetermined nip formed between them, and rotate while being heated. The separators separate a fixed recording medium from the upper and lower rollers to prevent the recording medium from becoming tacked to the upper and roller rollers. The separators are disposed in such a way that a predetermined gap is created between the separator and a corresponding roller. The separator includes a plurality of tongues and spacers. The tongues are mounted on, for example, a mounting board and aligned in a longitudinal direction to act directly on the recording medium to detack the recording medium from the roller. The spacers are in pressure contact with the roller and maintain a predetermined gap between the roller and the tongues. The separator is rotatable about an axis parallel to a rotational shaft of the roller and is urged against the roller. As a result, even when the roller changes in diameter due to thermal expansion, the separator maintains the gap. A problem with the aforementioned conventional fixing unit is that the recording medium may be caught by some of the tongues to become jammed. When the roller changes in diameter at its longitudinal end portions due to thermal expansion, the spacer at one end portions moves out of contact with the roller, failing to maintain the predetermined gap between the tongues and the roller across the length of the roller. SUMMARY OF THE INVENTION An object of the invention is to solve the aforementioned problems with the conventional fixing unit. An object of the invention is to provide a fixing apparatus and an image-forming apparatus that incorporates the fixing apparatus, the fixing apparatus including spacers pressed against a roller to maintain a gap between the spacer and the roller even when the diameter of the roller changes due to thermal expansion. A fixing apparatus comprising: a fixing member that is heated while rotating, the fixing member being in pressure contact with a recording medium that is advancing so that the developer deposited on the recording medium is fused; a guiding member extending across a path of the recording medium so that a predetermined amount of gap is defined between the guiding member and the fixing member, the guiding member guiding the recording medium to separate from the fixing member; spacers disposed at longitudinal end portions of the guiding member outside of the path, the spacers being between the fixing member and the guiding member to define the predetermined amount of gap, spacers being movable in directions at an angle with a surface of the recording medium; and an urging member that urges the spacers against the fixing member. The fixing member rotates about a first axis and the spacers are rotatable about a second axis substantially parallel to the first axis. The spacers are rotatable about the second axis independently. The guiding member is resilient. The guiding member and the spacers are coupled in such a way that the guiding member is movable relative to the spacers. The guiding member engages the spacers resiliently. The fixing apparatus further includes an adjustment member that adjusts a positional relation between the guiding member and the spacers. The guiding member is shaped to define a larger gap at the middle portion of the guiding member than at the longitudinal end portions of the guiding member. The fixing apparatus further includes an inclination adjustment mechanism that adjusts an inclination of the guiding member relative to the fixing member. The inclination adjustment mechanism operates to incline the guiding member while also maintaining the predetermined gap between the guiding and the fixing member. A fixing apparatus includes: a fixing member that is heated and is rotating about a first axis, the fixing member being in pressure contact with an advancing recording medium in such a way that the developer deposited on the recording medium is fused; a guiding member that defines a predetermined amount of gap between the guiding member and the fixing member, the guiding member guiding the recording medium to separate from the fixing member; spacers disposed at longitudinal end portions of the guiding member outside of the path, the spacers being disposed between the fixing member and the guiding member to define the predetermined amount of gap, wherein the spacers are rotatable independently about a second axis substantially parallel to the first axis so that the spacers are movable in directions at an angle with a surface of the recording medium; and an urging member that urges the spacers against the fixing member. The fixing apparatus further includes an adjustment mechanism that adjusts a positional relation between the guiding member and the spacers. The fixing apparatus further includes an inclination adjustment mechanism that adjusts an inclination of the guiding member relative to the fixing member. The inclination adjustment mechanism operates to incline the guiding member while also maintaining the predetermined gap between the guiding and the fixing member. An image-forming apparatus incorporates the aforementioned fixing apparatus and an image-forming section that forms an image with a developer on a recording medium. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limiting the present invention, and wherein: FIG. 1 is a schematic view illustrating an image-forming apparatus according to a first embodiment; FIG. 2 is a perspective view of a fixing unit according to the first embodiment; FIG. 3 is a side view of the fixing unit according to the first embodiment; FIGS. 4A-4B are perspective views of an upper separator; FIGS. 5A-5B are perspective views of a lower separator; FIGS. 6A-6C illustrate the lower separator when it is twisted, FIG. 6A being a left side view, FIG. 6B being a front view, and FIG. 6C being a right side view; FIG. 7 is a side view of an upper spacer and an upper separator according to a second embodiment; FIG. 8 is an exploded perspective view illustrating the upper spacer and upper separator of FIG. 7; FIG. 9 is a side view illustrating a lower spacer and a lower separator according to the second embodiment; FIG. 10 is an exploded perspective view illustrating how the lower spacer and lower separator are assembled; FIG. 11 is a perspective view of a fixing unit according to a third embodiment; FIG. 12 is a perspective view of the fixing unit of FIG. 11 when a top plate is removed; FIG. 13 is a perspective view of a pertinent portion of an upper separator of FIG. 11; FIG. 14A is a perspective view of a pertinent portion of a lower separator according to the third embodiment; FIG. 14B is an exploded perspective view of a pertinent portion of the lower separator of FIG. 14A; FIG. 15 is across-sectional side view of the fixing unit according to the third embodiment; FIGS. 16A-16C illustrate the twisting of the fixing unit according to the third embodiment, FIG. 16A being a left side view, FIG. 16B being a front view, and FIG. 16C being a right side view; FIG. 17 is a perspective view of left and right end portions of the lower separator according to fourth embodiment; FIG. 18A is an exploded perspective view of a pertinent portion of the lower separator and a holder of FIG. 17; FIG. 18B is another exploded perspective view of the lower separator and the holder of the third embodiment; FIG. 19 is a perspective view of a fixing unit according to a fifth embodiment when an upper roller and a lower roller are dismounted; FIG. 20A is a fragmentary perspective view of a pertinent portion of a lower separator according to a sixth embodiment; FIG. 20B is a side view of a pertinent portion of the lower separator according to the sixth embodiment; FIG. 21 is a side view of a fixing unit according to a seventh embodiment; FIG. 22 is a cross-sectional side view of an upper roller of FIG. 21; FIG. 23 is a cross-sectional side view of a lower roller of FIG. 21; FIG. 24 illustrates amounts of gap between an upper separator and an upper roller, and amounts of gap between a lower separator and a lower roller; FIG. 25 is a side view of a fixing unit according to an eighth embodiment; FIG. 26 is a perspective view of an inclining mechanism of a separator according to the eighth embodiment; FIG. 27A illustrates a controller and a thickness sensor according to the eighth embodiment; and FIG. 27B illustrates the inclining mechanism according to the eighth embodiment. DETAILED DESCRIPTION OF THE INVENTION First Embodiment {Construction} Embodiments of the invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view illustrating an image-forming apparatus according to a first embodiment. Referring to FIG. 1, an image-forming apparatus 100 is a composite apparatus of any type that performs functions of an electrophotographic printer, a facsimile machine, a copier, and a fax-and-copier. The present invention will be described with respect to a case in which the image-forming apparatus 100 is a color electrophotographic printer. There are four process units 151a-151d in tandem for forming yellow, magenta, cyan, and black images, respectively. The process units 151a-151d are aligned along a transport path in which a recording medium 24 is transported. Each of the process units 151a-151d includes a photoconductive drum 152, a charging unit 153, and an exposing unit 154. The charging unit 153 and exposing unit 154 are disposed around the photoconductive drum 152. The charging unit 153 charges the surface of the photoconductive drum 152, and the exposing unit 154 selectively illuminates the charged surface of the photoconductive drum 152 to form an electrostatic latent image on the photoconductive drum 152. A developing unit 155 and a cleaning unit 156 are also disposed around the photoconductive drum 152. The developing unit 155 applies toner to the electrostatic latent image formed on the photoconductive drum 152. The cleaning unit 156 removes residual toner from the surface of the photoconductive drum 152. The photoconductive drum 152 is driven in rotation by means of gears and a drive source, not shown. A paper cassette 157 holds a stack of the recording medium 24 such as paper. A hopping roller 158 is disposed over the paper cassette 157 and feeds the recording medium 24 from the paper cassette 157 on a sheet-by-sheet basis. Registry rollers 159a and 159b are disposed downstream of the hopping roller 158 with respect to a direction of travel of the recording medium 24. The registry rollers 159a and 159b cooperate with pinch rollers 160a and 160b, respectively, to hold the recording medium 24 therebetween in a sandwiched relation, thereby advancing the recording medium 24 with a least amount of skew. The recording medium 24 is advanced until a part of the leading edge of the recording medium 24 abuts the registry roller 159b at rest, and then advanced little further so that the entire leading edge abuts the registry rollers 159a and 159b. In this manner, the hopping roller 158 and registry rollers 159a and 159b are operatively driven in rotation by a drive source, not shown. A transfer roller 167 opposes the photoconductive drum 152 and is formed of a semiconductive rubber material. The transfer roller 167 and photoconductive drum 152 receives different bias voltages, so that the potential difference between the photoconductive drum 152 and the transfer roller 167 causes the toner on the photoconductive drum 152 to be transferred onto the recording medium 24. A fixing unit 163 includes a heat roller and a backup roller by which the toner image on the recording medium 24 is fused by heat and under pressure. Discharge rollers 164a and 164b are driven in rotation by a drive source, not shown, and cooperate with the pinch rollers 165a and 165b, respectively, to transport the recording medium 24 in a sandwiched relation. {Operation of the Image-Forming Apparatus} The operation of the aforementioned image-forming apparatus 100 will be described. A stack of the recording medium 24 is held in the paper cassette 157 and the hopping roller 158 feeds the recording medium 24 from the paper cassette 157 to the transport path on a sheet-by-sheet basis. The recording medium 24 is then held between the registry rollers 159a and 159b and pinch rollers 160a and 160b in a sandwiched relation and transported to a transfer point defined between the photoconductive drum 152 and the transfer roller 167 of the process unit 151a. Thereafter, the recording medium 24 held between the photoconductive drum 152 and the transfer roller 167 is advanced as the photoconductive drum 152 rotates. Subsequently, the recording medium 24 passes through the process units 151b, 151c, and 151d, so that the toner images of corresponding colors are transferred onto the corresponding medium 24 in registration. The toner images of the respective colors transferred onto the recording medium 24 in registration are fused into a permanent image in the fixing unit 163. Then, the recording medium 24 is further transported while being held between the discharge rollers 164a and 164b in a sandwiched relation. The recording medium 24 is finally discharged to a stacker 166 located outside of the image-forming apparatus 100. In this manner, a color image is formed on the recording medium 24 without color shift. {Fixing Unit} The fixing unit 163 will be described. FIG. 2 is a perspective view of the fixing unit 163. FIG. 3 is a side view of the fixing unit 163. In FIG. 3, reference numerals 23 and 24 denote the upper roller and recording medium, respectively. FIGS. 4A and 4B are perspective views of an upper separator 22. FIGS. 5A and 5B are perspective views of a lower separator 12. Referring to FIG. 5A, a holder 11 and the lower separator 12 are securely assembled in an integral assembly. Lower spacers 13 and 14 are firmly fixed to left and right end portions of the lower separator 12. The holder 11 has fulcrum holes 11a and 11b formed therein, which receive posts 17 and 18 provided on side plates 15 and 16 (FIG. 2), respectively. The torsion springs 19 and 20 urge the lower spacers 13 and 14 against a lower roller 21 that operates as a fixing means (FIG. 3). The upper separator 22 is of similar configuration to the lower separator 12. The lower separator 12 and upper separator 22 in the embodiment are in the shape of a thin rectangular plate of SUS (stainless steel) Alternatively, the lower separator 12 and upper separator 22 may be a thin plate of metal such as phosphor bronze or any other metal materials providing that the material has resiliency. The lower separator 12 and lower spacers 13 and 14 may be secured together by a bonding agent, bolting, or fitting. The size of gaps between the upper separator 22 and upper roller 23 and between the lower separator 12 and lower roller 21 are selected based on test results when continuous printing of 10 pages of 240% solid images was performed in a high-temperature and high-humidity environment (30° C., 80%) on thin paper having a top margin of 3.75 mm. The gap between the upper separator 22 and upper roller 23 is selected to be 0.37±0.06 mm. The gap between the lower separator 12 and lower roller 21 is selected to be 0.21±0.07 mm. The gap may be changed according to the printing conditions. {Operation of Fixing Unit} The operation of the fixing unit 163 of the aforementioned configuration will be described. When the image-forming apparatus 100 is powered on and a printing operation is initiated, the recording medium 24 is advanced to the fixing unit 163. If the recording medium 24 is about to become tacked to the upper roller 23, the upper separator 22 separates the recording medium 24 from the upper roller 23. If the recording medium 24 is about to become tacked to the lower roller 21, the lower separator 12 separates the recording medium 24 from the lower roller 21. The thermal expansion of the lower roller 21 causes the lower spacers 13 and 14 to rotate about the posts 17 and 18, so that the spacers are movable substantially in directions at an angle with a surface of the recording medium 24 or a direction of travel of the recording medium 24. Because the lower spacers 13 and 14 are fixed to the lower separator 12, the lower separator 12 is twisted but a predetermined amount of gap is maintained between the lower roller 21 and the lower separator 12. The top margin portion of the recording medium 24, which is usually difficult to become tacked to the lower roller 21, is guided by the lower separator 12 to separate from the lower roller 21. FIGS. 6A-6C illustrate the lower separator 12 when it is twisted, FIG. 6A being a left side view, FIG. 6B being a front view, and FIG. 6C being a right side view. Because the lower spacers 13 and 14 and the lower separator 12 are secured together, even if the longitudinal end portions of the lower roller 21 have different diameters due to different amounts of thermal expansion, the twisted lower separator 12 still maintains the same gap between the lower roller 21 and the lower separator 12. This is true for the gap between the upper separator 22 and the upper roller 23. In the first embodiment, a means is provided for pressing the lower spacers 13 and 14 against the lower roller 21 and the lower spacers 13 and 14 are secured to the lower separator 12, thereby maintaining a predetermined gap between the lower roller 21 and the lower separator 12. When the diameter of the lower roller 21 changes due to thermal expansion, the lower spacers 13 and 14 rotate slightly about the posts 17 and 18 correspondingly. As a result, the lower separator 12 is twisted while also yielding a stable amount of gap to ensure the separation of the recording medium 24 from the lower roller 21. The upper separator 22 is of the same configuration as the lower separator 12, so that the gap between the upper separator 22 and the upper roller 23 is maintained constant likewise. The first embodiment may be applicable not only to a fixing unit incorporating rollers but to a fixing unit incorporating a fixing belt. Second Embodiment Elements of the same structure as those in the first embodiment have been given the same reference numerals and the description thereof is omitted. A description is also omitted of the same operations and advantages as the first embodiment. The second embodiment reduces twisting of an upper separator 111 and lower separator 121 that would otherwise occur due to the thermal expansion of the upper roller 23 and lower roller 21, and twisting and variations of dimensions of structural members such as the frames of the fixing unit 163. FIG. 7 is a side view of an upper spacer 112 and the upper separator 111 assembled together. FIG. 8 is an exploded perspective view illustrating the upper spacer 112 and upper separator 111 of FIG. 7. As shown in FIGS. 7 and 8, a holder 113 is a metal plate into which the post 114 is fitted tightly. The upper separator 111 has holes 111a formed in its longitudinal end portions, the holes 111a receiving posts 114 of the holder 113 for securing the upper spacer 112. Only one of the holes 111a is shown. The upper spacer 112 fastened to the holder 113 by means of a bolt 117 inserted into a threaded hole 113e. The upper separator 111 is placed on the upper spacer 112 bolted to the holder 113 and washers 115 and E rings 116 are mounted to the posts 114, so that the upper separator 111 will not disengage from the post 114 but is allowed to slightly move along the length of the post 114 and in directions shown by arrows A and B. The same structure as that in FIG. 8 is provided on the other end of the upper separator 111. The mounting construction of a lower spacer 122 and a lower separator 121 will be described. FIG. 9 is a side view illustrating the lower spacer 122 and lower separator 121. FIG. 10 is an exploded perspective view illustrating the lower spacer 122 and lower separator 121. Referring to FIGS. 9 and 10, the holder 123 is formed of a metal plate and a post 124 is firmly fitted into the holder 123. The lower separator 121 has a hole 121a formed in its each longitudinal end portion, into which the post 124 of the holder 123 extends through the lower spacer 122. The lower spacer 122 is fastened to the holder 123 by means of a screw 127 inserted into a threaded hole 128. The lower separator 121 is placed on the lower spacer 122 screwed to the holder 123 and a washer 125 and an E ring 126 are mounted to the post 124, so that the lower separator 121 will not disengage from the post 124. The E ring 126 prevents the lower separator 121 and lower spacer 122 from disengaging from the post 124 but allows slight movement of the lower separator 121 relative to the lower spacer 122 along the length of the post 114 in a direction shown by arrows C and D in FIG. 9. The same structure as that in FIG. 9 is provided on the other end of the lower separator 121. The holders 113 are generally U-shaped with opposing side portions 113a and 113b extending in parallel. The opposed side portions 113a and 113b have holes 113c and 113d, respectively, through which a shaft 119 extends. The holders 123 are generally U-shaped with opposing side portions 123a and 123b extending in parallel. The opposed side portions 123a and 123b have holes 123c and 123d, respectively, through which a shaft 129 extends. The shafts 119 and 129 are parallel to the upper roller 23 and lower roller 21, respectively, so that the upper separator 111 is parallel to the upper roller 23 and the lower separator 21 is parallel to the lower roller 21. The operation of the fixing unit 163 of the aforementioned configuration will be described. The holder 113 assembled to one longitudinal end of the upper separator 111 and another holder assembled to the other longitudinal end are urged by torsion springs, not shown, to rotate about the shaft 119 toward the upper roller 23. As a result, the upper spacers 112 (only one of which is shown in FIG. 8) that are fixed on the holder 113 are urged against the upper roller 23 under a predetermined pressure and movable in directions at an angle with the surface of the recording medium 24 or a direction of travel of the recording medium 24. The holder 123 assembled to one longitudinal end portion of the lower separator 121 and another holder (not shown) assembled to the other longitudinal end portion are urged by torsion springs, not shown, to rotate about the shaft 129 toward the lower roller 21. As a result, the lower spacers 122 that are fixed on the holder 123 and another holder are urged against the lower roller 21 under a predetermined pressure and movable in directions at an angle with the surface of the recording medium 24 or a direction of travel of the recording medium 24. The lower spacer 122 and upper spacer 112 rotate about the shafts 129 and 119, respectively, and are urged against the lower roller 21 and upper roller 23, respectively. Thus, as long as the shafts 119 and 129 are parallel to the upper roller 23 and lower roller 21, respectively, a uniform amount of gap between the lower roller 21 and lower separator 121 should be maintained across the lower separator 121, and a uniform amount of gap between the upper roller 23 and upper separator 111 should be maintained across upper separator 111. However, if the lower spacers 122 are to be mounted firmly on the left and right longitudinal ends of the lower separator 121, then the lower spacers 122 cannot be in even contact with the lower roller 21 when the fixing unit 163 is twisted or the lower separator 121 is assembled with very small dimensional errors. In other words, the gap between the lower separator 121 and the lower roller 21 is either larger or smaller at one longitudinal end of the lower roller 23 than at the other. Likewise, if the upper spacers 112 are to be mounted firmly on the left and right longitudinal end portions of the upper separator 111, then the upper spacers 112 cannot be in even contact with the upper roller 23 when the fixing unit 163 is twisted or the upper separator 111 are assembled with very small dimensional errors. In other words, the gap between the upper separator 111 and the upper roller 23 is either larger or smaller at one longitudinal end of the upper roller 23 than at the other. The upper spacer 112 is adapted to move relative to the upper separator 111 in a direction shown by arrows A and B in FIG. 7. Another spacer, not shown, mounted at another longitudinal end of the upper separator 121 is adapted to move in the same manner as the upper spacer 112 in FIG. 7. This configuration allows setting of the gaps between the upper roller 23 and upper separator 111 at both longitudinal end portions of the upper roller 23 irrespective of the torsional deformation of the fixing unit 163. The lower spacer 122 is adapted to move relative to the lower separator 121 in a direction shown by arrows C and D in FIG. 9. Another spacer, not shown, mounted at another longitudinal end of upper separator 121 is adapted to move in the same manner as the lower separator 122 in FIG. 9. This configuration allows setting of the gaps between the lower roller 21 and lower separator 121 at both longitudinal end portions of the lower roller 21 irrespective of the torsional deformation of the fixing unit 163. In the present embodiment, the upper and lower spacers 112 and 122 are mounted to the upper and lower separators 111 and 121, respectively, in such a way that the upper and lower spacers 112 and 122 are movable relative to the upper and lower separators 111 and 121, respectively. Thus, even when the fixing unit 163 is twisted, the uniform gaps can be maintained between the upper roller 23 and separator 111 across the length of the upper roller 23 and between the lower roller 21 and lower separator 121 across the length of the lower roller 21. Thus, even when the image-forming apparatus 100 operates at a high speed, the fixing unit 163 will not lose the ability to prevent the recording medium 24 from becoming tacked to the upper roller 23 and lower roller 21. Third Embodiment Elements similar to those in the first and second embodiments have been given the same reference numerals and the description thereof is omitted. FIG. 11 is a perspective view of a fixing unit according to a third embodiment. FIG. 12 is a perspective view of the fixing unit of FIG. 11 when a top plate is removed. FIG. 13 is a perspective view of a pertinent portion of an upper separator 57. FIG. 14A is a perspective view of a pertinent portion of a lower separator 62. FIG. 14B is an exploded perspective view of a pertinent portion of the lower separator 62. FIG. 15 is a cross-sectional side view of the fixing unit. FIGS. 16A-16C illustrate the twisting of the fixing unit, FIG. 16A being a left side view, FIG. 16B being a front view, and FIG. 16C being a right side view. The upper and lower separators 57 and 62 are of similar configuration and therefore a description will be given of only the lower separator for simplicity's sake. Referring to FIG. 14A and FIG. 14B, a plate-like holder 61 extends longitudinally immediately under the lower separator 62 to support the lower separator 62. The holder 61 and the lower separator 62 are assembled together in an integral assembly and have elongated holes 61a and 62a formed at their longitudinal end portions, respectively, the elongated holes 61a and 62a extending in directions shown by arrows E in FIGS. 14A and 14B. A left post 65 is fixed to a bracket 63 and a right post 66 is fixed to a right bracket 64. The left and right posts 65 and 66 extend into the elongated holes 61a and 62a. Washers and C rings are attached to the left and right posts 65 and 56, thereby preventing lower spacers 69 and 70 and the lower separator 62 from disengaging from the left and right posts 65 and 66. In this manner, the lower spacers 69 and 70 and lower separator 62 are assembled together while at the same time they are allowed to move along the left and right posts 65 and 66. A fastening means such as bonding, bolting, or fitting may be employed as required to secure the holder 61 to the separator 62, the left bracket 63 to the left post 65, and the right bracket 64 to the right post 66. A compression spring 67 fits over a projection 61b of the holder 61 and is held between a left end portion of the holder 61 and the left bracket 63 in a sandwiched relation. Likewise, a compression spring 68 fits over another projection (not shown) of the holder 61 and is held between a right end portion of the holder 61 and the right bracket 64 in a sandwiched relation. The compression springs 67 and 68 urge the separator 62 and holder 61 in a direction shown by arrow E against the lower spacers 69 and 70, respectively. The lower spacers 69 and 70 are pivotal about the post 51 mounted to side plates 52 and 53 (FIGS. 11 and 12). The lower spacers 69 and 70 are urged by torsion springs, not shown, similar to torsion springs 19 and 20 in FIG. 3 against the lower roller 21 just as in the first embodiment. Likewise, the upper spacers 58 and 59 are pivotal about posts 55 and 56 (FIG. 13), so that the upper spacers 58 and 59 are urged by the torsion springs, not shown, similar to torsion springs 19 and 20 in FIG. 3 against the upper roller 23. The upper spacers 58 and 59 are rotatable so that the upper spacers 58 and 59 are movable substantially in directions at an angle with the surface of the recording medium 24 or a direction of travel of the recording medium 24. The fixing unit 163 of the aforementioned configuration will be described. When the image-forming apparatus 100 is powered on and a printing operation is initiated, the recording medium 24 is advanced to the fixing unit 163 as shown in FIG. 15. If the recording medium 24 is about to become tacked to the upper roller 23, the upper separator 57 separates the recording medium 24 from the upper roller 23. If the recording medium 24 is about to become tacked to the lower roller 21, the lower separator 62 separates the recording medium 24 from the lower roller 21. At this moment, in addition to the operation of the first embodiment, the small gaps between the lower spacers 69 and 70 and the lower separator 62 ensure a uniform gap between the lower separator 62 and the lower roller 21 across the length of the lower roller 21. The left and right posts 65 and 66 firmly fit into the end portion of the holder 61 and extend through elongated holes 62a formed in the lower separator 62 and elongated holes 61a formed in the holder 61. C rings are mounted to the end portions of the left and right posts 65 and 66 in such a way that the lower separator 62 is vertically slightly movable. The elongated holes 62a and 61a extend in a direction parallel to the directions in which the compression springs 67 and 68 urge the lower separator 62 toward the lower roller 21. The lower separator 62 is also movable in the directions in which the elongated holes 62a and 61a extend. Thus, even when the lower roller 21 has a larger or smaller diameter at one longitudinal end than at the other longitudinal end due to thermal expansion, the compression springs 67 and 68 and the gaps between lower spacers 69 and 70 and the lower separator 62 cooperate with one another to prevent the lower separator 62 from being twisted. In this manner, a uniform gap between the lower roller 21 and lower separator 62 is maintained across the length of the lower roller 21. A longitudinal edge of the lower separator 62 still extends parallel to the longitudinal surface of the lower roller 21 and lies in the same plane as the rotational axis of the lower roller 21. As described above, the lower separator 62 is assembled in an integral assembly with the holder 61 and supported such that the left and right longitudinal end portions of the separator 62 are independently movable relative to the lower roller 21. Thus, for example, even when thermal deformation of the lower roller 21 causes a difference in the diameter of the lower roller 21 between the longitudinal end portions of the lower roller 21, there is no situation where only one of the lower spacers 69 and 70 remains in contact with the roller 21. This provides reliable separation of the recording medium 24 from the lower roller 21. Fourth Embodiment Elements similar to those in the first to third embodiments have been given the same reference numerals and the description thereof is omitted. FIG. 17 is a perspective view of left and right end portions of a lower separator 71. FIG. 18A is an exploded perspective view of a pertinent portion of the lower separator 71 and a holder 72. FIG. 18B is another exploded perspective view of the lower separator 71 and a holder 72. The upper and lower separators according to the fourth embodiment are of the same configuration and therefore a description will be given of only the lower separator 71 for simplicity's sake. Referring to FIG. 18A and FIG. 18B, the lower separator 71 has an elongated hole 71a, a projection 71c, and U-shaped cutout 71b, which are formed in each of the longitudinal end portions of the lower separator 71. A holder 72 has an elongated hole 72a, a projection 72c, and U-shaped cutout 72b, which are formed in each of the longitudinal end portions of the holder 72. The holder 72 and lower separator 71 are assembled in an integral assembly. Posts 74 and 75 and a lower spacer 76 are secured to a bracket 73. The bracket are rotatable about a hole 73c in such a way that the lower spacer 76 moves substantially in direction at an angle with a direction of travel of the recording medium 24. The posts 74 and 75 extend through elongated holes formed in a slider 77 mounted on the spacer 76 such that the slider 77 is slidable in directions shown by arrows F and G. Washers 78 and 79 are mounted on the posts 74 and 75 from above the lower separator 71 and then E rings 80 and 81 are mounted on the posts 74 and 75. A compression spring 82 is mounted between an angled portion 73a of the bracket 73 and an angled portion 77b of the slider 77, urging the slider 77 in a direction shown by arrow F in FIG. 18A relative to the bracket 73. A compression spring 83 is mounted between an angled portion 77a and the holder 72, and urges the holder 72 and lower separator 71 in a direction shown by arrow G against tongues 77c of the slider 77. The angled portion 73b has a threaded hole formed therein. A bolt 84 is threaded into the threaded hole in the angled portion 73b in the G direction in FIG. 18A until the bolt 84 abuts the angled portion 77b. Referring to FIG. 18A, screwing the bolt 84 in the forward direction causes the slider 77 to slide in the direction shown by arrow G, and screwing the bolt 84 in the reverse direction causes the slider 77 to slide in the direction shown by arrow F. The operation of the fixing unit 163 of the aforementioned configuration will be described. The present embodiment allows adjusting of the relative position between the lower separator 71 and the lower spacer 76 at longitudinal end portions. Therefore, a proper amount of gap between the lower roller 21 and lower separator 71 can be ensured across the lower separator 71 for reliable separation of the recording medium 24 from the lower roller 21. An upper separator, not shown, is of the same configuration as the lower separator 71. Thus, a proper amount of gap between the upper separator and the upper roller 23 can be maintained for reliable separation of the recording medium 24 from the upper roller 23. Fifth Embodiment Elements similar to those in the first to fourth embodiments have been given the same reference numerals and the description thereof is omitted. FIG. 19 is a perspective view of a fixing unit 163 according to a fifth embodiment when an upper roller 23 and a lower roller 21 are dismounted from the fixing unit 163. Referring to FIG. 19, a shaft 91 extends through brackets 93 and 94 and is secured to side plates 97 and 98 so that an upper separator 99 is rotatably supported on the shaft 91 via the brackets 93 and 94. Likewise, a shaft 92 extends through brackets 95 and 96 and is secured to side plates 97 and 98 so that a lower separator 89 is rotatably supported on the shaft 92 via the brackets 95 and 96. The operation of the fixing unit 163 of the aforementioned configuration is the same as the first and third embodiment and the description thereof is omitted. In the fifth embodiment, the brackets 93 and 94 and brackets 95 and 96 rotate on the shafts 91 and 92, respectively, the brackets 93-96 restrict the lateral movement of the upper separator 99 and lower separator 89 along the shafts 91 and 92. Thus, a uniform gap can be maintained between the upper separator 99 and the upper roller 23 across the upper separator 99, and a uniform gap can be maintained between the lower separator 89 and the lower roller 21 across the lower separator 89. The uniform gaps provide reliable separation of the recording medium 24 from the upper and lower rollers 23 and 21. Sixth Embodiment Elements similar to those in the first to fifth embodiments have been given the same reference numerals and the description thereof is omitted. FIG. 20A is a fragmentary perspective view of a pertinent portion of an upper separator 101 according to a sixth embodiment. FIG. 20B is a side view of a pertinent portion of the upper separator 101. Referring to FIG. 20A and FIG. 20B, a post 106 is secured to a bracket 107 and extends through the upper separator 110. The bracket 107 supports the upper spacer 108 from under and is secured to the upper spacer 108. The upper separator 101 and the holder 102 are assembled in an integral assembly by using an adhesive, and mounted on the upper spacer 108. A washer 104 and an E ring 105 are mounted on a free end portion of the post 106. The fixing unit 163 of the aforementioned configuration operates in the same manner as the first embodiment and the third to fifth embodiments, and therefore the description thereof is omitted. In the sixth embodiment, the upper separator 101 is mounted in such a way that it is slightly movable vertically in a direction in which the post 106 extends. A wave washer 104 is mounted between the washer 103 and the E ring 105 so that the wave washer 104 absorbs gaps among the E ring 105, washer 103, and holder 102. This ensures a reliable gap between the upper separator 101 and the upper roller 23 for reliable separation of the recording medium 24 from the upper roller 23. A lower separator, not shown, is of the same configuration as the upper separator 101, so that a proper amount of gap is maintained between the upper separator 101 and the upper roller 23 for reliable separation of the recording medium 24 from the upper roller 23. The use of the wave washer 104 can absorb unwanted small gaps among the structural members to ensure a predetermined amount of gap between the upper roller 23 and the upper separator 101 across the length of the upper roller 23. This in turn ensures reliable separation of the recording medium 24 from the upper roller 23. Seventh Embodiment In the first to sixth embodiments, the upper and lower separators are in the form of a single long plate that extends across the width of the transport path of the recording medium 24. The gap between the lower separator and the lower roller 21 and the gap between the upper separator and the upper roller 23 should be selected by taking into account that the lower roller 21 and upper roller 23 deform in their middle portions. In a seventh embodiment, the lower separator and upper separator have cutouts 41b and 42b (FIG. 24) formed in the middle portions thereof. The cutouts 41b and 42b allow reliable separation of the recording medium 24 from the lower roller 21 and upper roller 23 even when the lower roller 21 and upper roller 23 deform at their middle portions. In the seventh embodiment, elements similar to those in the first to sixth embodiments have been given the same reference numerals and the description thereof is omitted. FIG. 21 is a side view of a fixing unit according to the seventh embodiment. FIG. 22 is a cross-sectional side view of an upper roller 31. Referring to FIG. 21, the upper roller 31 is a heating member that fuses toner on the recording medium 24 and is driven in rotation by a drive motor, not shown, through a drive gear, not shown, mounted to one end of the upper roller 31. The upper roller 31 has a silicon rubber roller 31b formed on an aluminum pipe 31a. The silicone rubber roller 31b has a coating 31c thereon. The coating 31c is formed primarily of fluorocarbon resin that improves the separation of the recording medium 24 from the upper roller 31. The aluminum pipe 31a incorporates a halogen lamp 32 therein that can be controlled on and off by a power supply, not shown. A thermistor 33 is in contact with the surface of the upper roller 31 and detects the surface temperature of the upper roller 31 to turn on an off the halogen lamp 32. FIG. 23 is a cross-sectional side view of a lower roller 35. FIG. 24 illustrates amounts of gap between an upper separator 41 and the upper roller 31, and gap between a lower separator 42 and the lower roller 35. The lower roller 35 is disposed under the upper roller 31 and is in pressure contact with the upper roller 31 under a predetermined pressure. The lower roller 35 has a silicone rubber roller 35b formed on an aluminum pipe 35a. The silicone rubber roller 35b has a coating 35c formed thereon. The coating 35c is primarily formed of fluorocarbon resin that improves separation of the recording medium 24. The aluminum pipe 35a of the lower roller 35 is rotatably supported at its both longitudinal end portions by bearings 34. The bearings 34 are supported by compression springs 36. The lower roller 35 is urged against the upper roller 31 under a predetermined pressure. The upper roller 31 and lower roller 35 have silicone rubber rollers 31b and 35b, respectively. When the lower roller 35 is urged by the compression coil springs 36 against the upper roller 31, the silicone rubber rollers 31b and 35b deform to create a nip between them. As shown in FIG. 23, the aluminum pipe 35a also incorporates a halogen lamp 37 therein, which can be controlled on and off by a power supply, not shown. A thermistor 38 (FIG. 21) is in contact with the surface of the lower roller 31 and detects the surface temperature of the lower roller 35 to turn on an off the halogen lamp 37. As described above, the upper roller 31 and lower roller 35 have the silicone rubber rollers 31b and 35b formed on the aluminum pipes 31a and 35a, respectively. Thus, the upper roller 31 and lower roller 35 are not rigid but resilient. The silicone rubber roller 35b is higher in hardness than the silicone rubber roller 31b, so that the surface of the upper roller 31 is dented while the surface of the lower roller 35 remains substantially cylindrical. A front guide 40 is disposed upstream of the lower roller 35 with respect to the direction of travel of the recording medium 24, and guides the recording medium 24 toward the nip formed between the upper roller 31 and lower roller 35. An upper separator 41 and a lower separator 42 are disposed downstream of the upper roller 31 and lower roller 35 with respect to the direction of travel of the recording medium 24. The upper separator 41 extends along the upper roller 31 and is a substantially rectangular metal plate coated with fluorine that prevents toner deposition thereon. The upper spacers 43 are disposed at both longitudinal end portions of the upper separator 41 and outside of the width of a maxim size recording medium 24 that passes through the nip between the upper roller 31 and lower roller 35. The upper spacers 43 are urged against the upper roller 31 by a predetermined urging force. The lower separator 42 extends along the lower roller 35 and is a substantially rectangular metal plate coated with fluorine that prevents toner deposition thereon. The lower spacers 44 are disposed at both longitudinal end portions of the lower separator 42 and outside of the width of a maxim size recording medium 24 that passes through the nip between the upper roller 31 and lower roller 35. The upper spacers 43 are urged against the upper roller 31 by a predetermined urging force. Both the upper separator 41 and lower separator 42 are in the form of a metal plate and have longitudinally centered cutouts 41b and 42b as shown in FIG. 24. The cutouts 41b and 42b extend over a distance shorter than the width of the recording medium 24. Because the upper separator 41 and lower separator 42 in the form of metal plates extend along a heat-generating roller such as the upper and lower rollers 31 and 35, they tend to deform due to the heat radiated from the upper roller 31 and lower roller 35 as shown by the graph in FIG. 24. Referring to FIG. 24, a maximum thermal deformation occurs in a longitudinally middle portion of the upper separator 41 and lower separator 42. The thermal deformation of the upper separator 41 and lower separator 42 is smaller nearer the upper spacers 43 and lower spacers 44, respectively. The operation of the fixing unit 163 of the aforementioned configuration will be described. Upon a power-on command from a power supplying means, not shown, the halogen lamps 32 and 37 incorporated in the aluminum pipes 31a and 35a generate heat to raise the surface temperatures of the upper roller 31 and lower roller 35, respectively. The thermistors 33 and 38 detect the surface temperatures at all times and the halogen lamps 32 and 37 are controlled to turn on and off, thereby maintaining the surface temperatures of the upper and lower rollers 31 and 35 within a predetermined range. When the surface temperatures of the upper and lower rollers 31 and 35 fall in a predetermined temperature range, a drive motor, not shown, runs to operatively rotate the upper roller 31 through a gear train in a direction shown by an arrow in FIG. 21. Subsequently, the lower roller 35 urged by the compression coil springs 36 against the upper roller 31 is driven in rotation by the upper roller 31. The halogen lamps 32 and 37 heat the upper and lower rollers 31 and 35, which in turn heat the upper and lower separators 41 and 42. Thus, the upper and lower separators 41 and 42 are subjected to thermal deformation so that their longitudinally middle portions extend toward the upper and lower rollers 31 and 35, respectively. Because of the cutouts 41b and 42b, the upper separator 41 and lower separator 42 are a predetermined distance (e.g., 0.3 to 1.0 mm) further away from the upper and lower rollers 31 and 35 at the longitudinally middle portions than at the longitudinal end portions. This predetermined distance is selected to be equivalent to an amount of thermal deformation of the upper separator 41 and lower separator 42. Thus, even when the upper and lower separators 41 and 42 deform due to heat radiated from the upper and lower rollers 31 and 35, there are still a clearance between the longitudinally middle portion of the upper separator 41 and the upper rollers 31 and a clearance between the longitudinally middle portion of the lower separator 42 and the lower roller 35. This structure eliminates the need for mounting the upper and lower separators 41 and 42 away from the upper and lower rollers 31 and 35 more than necessary, thereby preventing inadvertent contact of the upper and lower separators 41 and 42 with the upper and lower rollers 31 and 35, respectively. When the upper and lower rollers 31 and 35 start rotating, the front guide 40 guides the recording medium 24 into the nip formed between the upper and lower rollers 31 and 35. The toner image on the recording medium 24 is fused by heat under pressure as the recording medium 24 passes through the nip. The toner acts as an adhesive that causes the recording medium 24 to become tacked to a coating 31c of the upper roller 31. Because there are only small clearances between the upper separator 41 and upon roller 31 and between the recording medium 24 and upper roller 35, the recording medium 24 will not become tacked to the upper roller 31 and lower roller 35 but pass between the upper separator 41 and lower separator 42 into the stacker 166 located outside of the image-forming apparatus 100. In particular, if the image-forming apparatus 100 has been designed to accept A3 size paper, the upper separator 41 and lower separator 42 only need to be controlled in flatness and parallelism at their longitudinal end portions. This alleviates requirements imposed on the components of the apparatus, thereby increasing yield of the components as well as reducing manufacturing costs. Eighth Embodiment The rectangular plate-like separators 41 and 42 have a large area that may contact the recording medium 24 when the recording medium 24 passes through the fixing unit 24, adversely affecting print quality. To prevent such a problem, the separators according to an eighth embodiment is adapted to incline at different angles according to the type of the recording medium 24, thereby preventing the separators from contacting the recording medium 24. Elements similar to those in the first to seventh embodiments have been given the same reference numerals and the description thereof is omitted. FIG. 25 is a side view of a fixing unit 163 according to an eighth embodiment. Referring to FIG. 25, an upper separator 131d and lower separator 132d are disposed downstream of the upper roller 31 and the lower roller 35 with respect to the direction of travel of the recording medium 24. The upper separator 131 has an upper spacer 131a attached to each of longitudinal end portions of the upper separator 131d. A spring, not shown, exerts a force that causes the upper separator 131d to pivot about a shaft 131b, so that the upper spacer 131a is brought into contact with the upper roller 31 under a predetermined pressure. The lower separator 132d has a lower spacer 132a attached to each of the longitudinal end portions. A spring, not shown, exerts a force that causes the lower separator 132d to pivot about a shaft 132b so that the lower spacer 132a is brought into contact with the lower roller 35 under a predetermined pressure. FIG. 26 is a perspective view of an inclining mechanism of a separator. Referring to FIG. 26, the upper spacer 131a has a cylindrical end portion 131e with a shaft 131c in line with a longitudinally extending edge of the upper spacer 131a. The shaft 131c extends into a bearing hole 162 formed in a side frame 161 so that the upper separator 131e can pivot about the shaft 131c in directions shown by arrows H and I. When the upper separator 131d is driven by a mechanism (FIG. 27B) to move, the cylindrical end portion 131e slides on the circumferential surface of the upper roller 31 so that the a predetermined amount of gap is maintained between the upper roller 31 and the upper separator 131d. The lower spacer 132a has the same structure as the upper spacer 131a and operates the same way as the upper spacer 131a and therefore the description thereof is omitted. FIG. 27A illustrates a controller 160 and a thickness sensor 150. When the surface temperatures of the upper and lower rollers 31 and 35 fall in a predetermined temperature range, the recording medium 24 is fed from the paper cassette 157. The recording medium 24 fed from the paper cassette 157 pushes up a thickness sensor 150, which displaces correspondingly in an upward direction shown by an arrow C to detect the thickness of the recording medium 24. The output of the thickness sensor 150 is sent to the control unit 160. Based on the output of the thickness sensor 150, the control unit 160 determines whether the recording medium 24 is ordinary paper or a transparency (OHP). FIG. 27B illustrates the inclining mechanism. Referring to FIG. 27B, a shaft 133a and a gear 146 are coupled via a link 144a. The gear 146 is operatively coupled to the upper roller 31 via an idle gear 148, a one-way gear 149, and a gear 147. The gear 147 is concentric to the upper roller 31 and is driven by a main motor and a gear train, not shown. When the upper and lower rollers 31 and 35 rotate in directions shown by arrows J, the recording medium 24 is pulled in between the upper and lower rollers 31 and 35 for a normal fixing operation, and the one-way gears 149 and 155 do not transmit the rotation of the gears 147 and 153 to idle gears 148 and 154. When the upper and lower rollers 31 and 35 rotate in directions shown by arrows K, the one-way gears 149 and 155 transmit the rotation of the gear 147 and 153 to the idle gears 148 and 154 so that the idles gears 148 and 154 and the gears 146 and 152 rotate in the directions shown by arrows. The operation of raising the upper separator and lower separator will be described. When the recording medium 24 is fed from the paper cassette 157, a control unit 160 causes the main motor to rotate the gear 147, one-way gear 149, and idle gear 148 by a predetermined amount in directions shown by arrows depending on the thickness of the recording medium. Thus, the shaft 131b rotates to move the upper separator 131d upward. A shaft 132b is coupled to the gear 152 via a link 144b. The gear 152 is operatively coupled to the lower roller 35 via the idle gear 154, one-way gear 155, and gear 153. The gear 153 is concentric to the lower roller 35 and is driven by the main motor and a gear train, not shown. When the recording medium 24 is fed from the paper cassette 157, the control unit 160 causes the main motor to rotate the gear 152, one-way gear 155, and idle gear 154 by a predetermined amount in directions shown by arrows depending on the thickness of the recording medium 24. Thus, the shaft 133b rotates to move the lower separator 132 upward. The operation of the fixing unit of the aforementioned configuration will be described. Upon receiving a power-on command from a power supplying means, not shown, the halogen lamps 32 and 37, incorporated in the aluminum pipes 31a and 35a of the upper roller 31 and lower roller 35, respectively, generate heat to raise the surface temperature of the upper roller 31 and lower roller 35, respectively. The thermistors 33 and 38 detect the surface temperatures of the upper roller 31 and lower roller 35 at all times and the halogen lamps 32 and 37 are controlled to turn on and off, thereby maintaining the upper and lower rollers 31 and 35 within a predetermined temperature range. When the surface temperatures of the upper and lower rollers 31 and 35 fall in a predetermined temperature range, a drive motor, not shown, runs to operatively rotate the upper roller 31 through a gear train in directions shown by arrows J in FIG. 27B. Subsequently, the lower roller 35 urged by the compression coil springs 36 against the upper roller 31 is driven in rotation by the upper roller 31. If it is determined that the recording medium 24 is a transparency, the control unit 160 causes the main motor to rotate by a predetermined amount in the reverse direction, so that the upper separator 131d moves upward and the lower separator 132d moves downward. Thus, the gears 147 and 153, one-way gears 149 and 155, idle gears 148 and 154, and gears 146 and 152 rotate by a predetermined amount in directions shown by arrows in FIG. 27B, thereby changing the inclination of the upper separator 131 and lower separator 132. When the upper separator 131d and the lower separator 132d are to be moved back to their original positions, the main motor and the gear mechanism further rotate by a predetermined amount in the reverse direction. The one way gears 149 and 155 transmit the rotation of the gears 147 and 153 to the gear 148 and 154 when the main motor rotates in the reverse direction and does not when the main motor rotates in the forward direction. The one way gears may be omitted if the gears 147 and 153 are allowed to rotate independently of the upper roller 31 and lower roller 35, respectively. Because the upper separator 131d and lower separator 132d can be inclined, a special recording medium such as transparency will be transported to the outside of the image-recording apparatus without touching the upper separator 131 after passing the nip. This prevents variations in transmission of light that passes through the OHP and the gloss of the thin media that would otherwise occur when the upper and lower separators 131d and 132d inadvertently touch the recording medium 24. The spacers are rotatable about an axis regardless of the changes in the diameter of rollers and in contact with the rollers close to the nip formed between the upper roller and the lower roller. Thus, the spacers can rotate or pivot about the axis in accordance with the changes in the diameter of the rollers, thereby maintaining a substantially constant gap between the rollers and the separators across the length of the separators. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art intended to be included within the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention generally relates to a fixing apparatus and an image-forming apparatus that incorporates the fixing apparatus. 2. Description of the Related Art A conventional electrophotographic image-forming apparatus uses a fixing unit that includes upper and lower rollers and separators. The upper and lower rollers abut each other with a predetermined nip formed between them, and rotate while being heated. The separators separate a fixed recording medium from the upper and lower rollers to prevent the recording medium from becoming tacked to the upper and roller rollers. The separators are disposed in such a way that a predetermined gap is created between the separator and a corresponding roller. The separator includes a plurality of tongues and spacers. The tongues are mounted on, for example, a mounting board and aligned in a longitudinal direction to act directly on the recording medium to detack the recording medium from the roller. The spacers are in pressure contact with the roller and maintain a predetermined gap between the roller and the tongues. The separator is rotatable about an axis parallel to a rotational shaft of the roller and is urged against the roller. As a result, even when the roller changes in diameter due to thermal expansion, the separator maintains the gap. A problem with the aforementioned conventional fixing unit is that the recording medium may be caught by some of the tongues to become jammed. When the roller changes in diameter at its longitudinal end portions due to thermal expansion, the spacer at one end portions moves out of contact with the roller, failing to maintain the predetermined gap between the tongues and the roller across the length of the roller. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of the invention is to solve the aforementioned problems with the conventional fixing unit. An object of the invention is to provide a fixing apparatus and an image-forming apparatus that incorporates the fixing apparatus, the fixing apparatus including spacers pressed against a roller to maintain a gap between the spacer and the roller even when the diameter of the roller changes due to thermal expansion. A fixing apparatus comprising: a fixing member that is heated while rotating, the fixing member being in pressure contact with a recording medium that is advancing so that the developer deposited on the recording medium is fused; a guiding member extending across a path of the recording medium so that a predetermined amount of gap is defined between the guiding member and the fixing member, the guiding member guiding the recording medium to separate from the fixing member; spacers disposed at longitudinal end portions of the guiding member outside of the path, the spacers being between the fixing member and the guiding member to define the predetermined amount of gap, spacers being movable in directions at an angle with a surface of the recording medium; and an urging member that urges the spacers against the fixing member. The fixing member rotates about a first axis and the spacers are rotatable about a second axis substantially parallel to the first axis. The spacers are rotatable about the second axis independently. The guiding member is resilient. The guiding member and the spacers are coupled in such a way that the guiding member is movable relative to the spacers. The guiding member engages the spacers resiliently. The fixing apparatus further includes an adjustment member that adjusts a positional relation between the guiding member and the spacers. The guiding member is shaped to define a larger gap at the middle portion of the guiding member than at the longitudinal end portions of the guiding member. The fixing apparatus further includes an inclination adjustment mechanism that adjusts an inclination of the guiding member relative to the fixing member. The inclination adjustment mechanism operates to incline the guiding member while also maintaining the predetermined gap between the guiding and the fixing member. A fixing apparatus includes: a fixing member that is heated and is rotating about a first axis, the fixing member being in pressure contact with an advancing recording medium in such a way that the developer deposited on the recording medium is fused; a guiding member that defines a predetermined amount of gap between the guiding member and the fixing member, the guiding member guiding the recording medium to separate from the fixing member; spacers disposed at longitudinal end portions of the guiding member outside of the path, the spacers being disposed between the fixing member and the guiding member to define the predetermined amount of gap, wherein the spacers are rotatable independently about a second axis substantially parallel to the first axis so that the spacers are movable in directions at an angle with a surface of the recording medium; and an urging member that urges the spacers against the fixing member. The fixing apparatus further includes an adjustment mechanism that adjusts a positional relation between the guiding member and the spacers. The fixing apparatus further includes an inclination adjustment mechanism that adjusts an inclination of the guiding member relative to the fixing member. The inclination adjustment mechanism operates to incline the guiding member while also maintaining the predetermined gap between the guiding and the fixing member. An image-forming apparatus incorporates the aforementioned fixing apparatus and an image-forming section that forms an image with a developer on a recording medium. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. | 20040713 | 20061107 | 20050120 | 65406.0 | 1 | LABOMBARD, RUTH NAOMI | IMAGE FORMING APPARATUS WITH PAPER SEPARATOR-FIXING ROLLER GAP MECHANISM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,889,344 | ACCEPTED | CMP polishing heads and methods of using the same | Polishing heads to polish the surface of a semiconductor wafer and methods of using the same are disclosed. A disclosed polishing head includes at least one rotating head to apply a downward force; and a plurality of vacuum cells to hold the wafer via a vacuum force and to convey a least some of the downward force from the at least one rotating head to the wafer. | 1. A CMP polishing head to polish the surface of a semiconductor wafer, comprising: a first rotating head to apply a downward force, the first rotating head being rotatable by a rotating axis; a second rotating head located under the first rotating head; an air bag located between the first and second rotating heads to convey at least some of the downward force from the first rotating head to the second rotating head; and a plurality of wafer holding cells located under the second rotating head to hold the wafer via a vacuum force and to convey a least some of the downward force from the second rotating head to the wafer. 2. A CMP polishing head as defined in claim 1 further comprising a vacuum line coupled to at least one of the wafer holding cells to provide the vacuum force. 3. A CMP polishing head as defined in claim 1 wherein at least one of the wafer holding cells is made of flexible rubber. 4. A CMP polishing head as defined in claim 1 wherein at least one of the wafer holding cells comprises a holding end having a wider area than an end opposite the holding end. 5. A CMP polishing head as defined in claim 1 wherein at least one of the wafer holding cells has a funnel shape. 6. A CMP polishing head as defined in claim 5 wherein the at least one of the wafer holding cells has a substantially circular cross-section through the funnel shape. 7. A method for performing chemical mechanical polishing of a semiconductor wafer comprising: holding the wafer by a vacuum force applied by a plurality of wafer holding cells; and rotating the wafer while applying a downward force to the wafer via the plurality of wafer holding cells. 8. A method as defined in claim 7 further comprising releasing the vacuum to release the wafer when the chemical mechanical polishing process is completed. 9. A method as defined in claim 7 further comprising applying downward force from a first rotating head to a second rotating head via an airbag. 10. A method as defined in claim 7, wherein the vacuum force is greater than the downward force. 11. A CMP polishing head to polish the surface of a semiconductor wafer, comprising: at least one rotating head to apply a downward force; and a plurality of vacuum cells to hold the wafer via a vacuum force and to convey a least some of the downward force from the at least one rotating head to the wafer. 12. A polishing head as defined in claim 11 wherein the at least one rotating head comprises a first rotating head and a second rotating head, and further comprising an air bag disposed between the first and second rotating heads. | FIELD OF THE DISCLOSURE The present disclosure relates generally to semiconductor fabrication and, more particularly, to CMP polishing heads and method of using the same. BACKGROUND As the integration of semiconductor devices increases, multi-layer interconnection technology has been put into practical use. Thus, local and global area planarization of an interlayer insulating layer has become important. A widely used CMP (Chemical Mechanical Polishing) method of polishing the surface of a semiconductor wafer employs chemical components contained in a slurry solution, a polishing pad, and a polishing agent. A CMP apparatus is most frequently used to polish the front face of a semiconductor wafer in fabricating semiconductor devices on the wafer. Generally, a wafer is planarized or softened at least one time during the fabricating process in order to make the surface of the wafer as flat as possible. In order to polish the wafer, the wafer is placed on a carrier, put into contact with a polishing pad covered with slurry and then pressed. Wafer polishing is then carried out by rotating the polishing pad and the wafer-loaded carrier. A prior art CMP apparatus for polishing a wafer includes a polishing platen, a polishing pad located over the polishing platen, a polishing head, and a retainer ring and/or membrane for holding the wafer in the bottom edge of the polishing head. The wafer is held in the retainer ring so that the surface of the wafer to be polished is disposed toward the polishing pad. The retainer ring has multiple grooves to facilitate the flow of polishing slurry to the surface of the wafer. The grooves are extended from the inner to the outer surface of the retainer ring. Each groove has a round shape structure. We will now look at the way in which the retainer ring and polishing pad are used in the prior art. To this end, FIG. 1a through FIG. 1c are schematic, cross-sectional, views which illustrate a retainer ring of a prior art polishing head. FIG. 1a is a schematic, cross-sectional, view illustrating the structure of a prior art CMP polishing head 18 for polishing the surface of a wafer. FIG. 1b and FIG. 1c are schematic, cross-sectional, views which illustrate the retainer ring 14. FIG. 1c is a cross-sectional view of the channels 16 of the retainer ring 14 depicted in FIG. 1b. Referring to FIG. 1a, the prior art CMP apparatus has a polishing pad 10 which is covered with the flow of polishing slurry. It also has a polishing head 18. The wafer 12 is positioned between the polishing pad 10 and the polishing head 18. A retainer ring 14 is disposed at the bottom edge of the polishing head 18. The retainer ring 14 holds the wafer 12 to prevent it from being derailed during the CMP process. The retainer ring 14 of the polishing head 18 has multiple grooves 16 to facilitate the flow of polishing slurry. The grooves 16 are extended from the inner surface of the retainer ring 14 to the outer surface of the retainer ring 14. The slurry flows uniformly on the surface of the wafer 12, since the grooves 16 act as passing channels to facilitate the flow of polishing slurry. FIG. 1b is a cross-sectional bottom view of the retainer ring 14. As mentioned above, the retainer ring 14 has multiple grooves 16 which extend from its inner surface to its outer surface. As shown in FIG. 1b, the grooves 16 are circularly shaped and skewed at a predetermined angle toward the outer rim against the rotating direction of the retainer ring 14. During a polishing process, the retainer ring 14 rotates with the desired speed and provides the whole area of the wafer 12 with a uniform flow of the polishing slurry through the grooves 16. As shown in FIG. 1c, the cross-sections of the channels 16 have a round shape 16a. Thus, the channels 16 facilitate the smooth flow of polishing slurry over the surface of the wafer in comparison with the rectangular shape of grooves sometimes employed in the prior art. The worn amount of the polishing pad may be reduced by preventing fast sticking of the polishing pad, so that the durability of the pad can be increased. Conventional CMP polishing heads have employed consumables such as a retainer ring or membrane, but these consumables cause a huge increase in maintenance costs. Volodarsky et al., U.S. Pat. No. 5,803,799, describes a polishing head for polishing a semiconductor wafer. The polishing head includes a housing, a wafer carrier movably mounted to the housing, and a wafer retainer movably mounted to the housing. Quek et al., U.S. Pat. No. 6,245,193, describes a substrate carrier head for use in a CMP apparatus. Park et al., U.S. Pat. No. 6,336,846, describes a chemical-mechanical polishing (CMP) apparatus having a polishing head onto which a semiconductor wafer is fixed for holding the surface of the semiconductor wafer in contact with the surface of a polishing pad. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a through FIG. 1c are cross-sectional views which schematically illustrate the retainer ring of a prior art polishing head. FIG. 2a through FIG. 2e are cross-sectional views which schematically illustrate an example CMP polishing head. DETAILED DESCRIPTION FIG. 2a schematically illustrates an example polishing head for polishing the surface of a wafer. The example polishing head of FIG. 2a is connected with a rotating axis 20. The polishing head comprises a first rotating head 21, a second rotating head 23, an air bag 22, and a plurality of wafer holding cells 28. The first rotating head 21 rotates and applies a downward force 30. The second rotating head 23 is installed under the first rotating head 21. The air bag 22 delivers the downward force 30 from the first rotating head 21 to the second rotating head 23, and is positioned between the first and the second rotating head 21, 23. The plurality of wafer holding cells 28 conveys the downward force 30 delivered from the second rotating head 23 to the wafer 26. The wafer 26 is held in place by a vacuum method as explained further below. The plurality of wafer holding cells 28 is located under the second rotating head 23. Conventional CMP polishing heads have held and released the wafer by employing either a retainer ring and membrane or a vacuum method employing a hole. However, the CMP polishing processes disclosed herein are carried out while holding the wafer 26 with a plurality of wafer holding cells 28 distributed throughout the whole area of the backside of the wafer 26. Each wafer holding cell 28 has a vacuum line 24 and applies a vacuum force to the wafer. FIG. 2b schematically illustrates an example wafer holding cell 28. Referring to FIG. 2b, the wafer holding cell 28 assists in holding the wafer 26 to prevent the wafer 26 from being derailed during a CMP process. The holding end of the wafer holding cell 28 has a wider area than its opposite end. The wafer holding cells 28 have a funnel shape and have a substantially circular cross-section through the funnel shape. FIG. 2c is a schematic, horizontal view of the example CMP polishing head of FIG. 2a. A method for operating a CMP polishing head of FIG. 2a comprises: holding a wafer by vacuum force with a plurality of wafer holding cells, wherein each of the wafer holding cells comprises a vacuum line and is connected with a second rotating head, performing a CMP process by rotating the wafer while applying downward force to the wafer through the plurality of wafer holding cells, and unloading the vacuum force from the plurality of wafer holding cells when the CMP process is completed. In other words, the wafer holding cells 28 engage and hold the backside of the wafer 26 through a vacuum line 24 positioned at the center of the inner portion in order to prevent the wafer 26 from being derailed. The vacuum force from the plurality of wafer holding cells 28 is greater than the downward force 30. In order to apply the downward force 30 from the second rotating head 23 to the whole area of the wafer 26, the wafer holding cells 28 are substantially evenly distributed on the backside of the wafer 26. Thus, we expect to effectively improve uniformity within the wafer. Preferably, the material for the plurality of wafer holding cells 28 comprises flexible rubber. The plurality of wafer holding cells 28 can hold and release the wafer 26 through the vacuum line 24 at the center of the inner portion. Also, the plurality of wafer holding cells 28 are uniformly positioned on the backside of the wafer 26 so that, unlike conventional polishing heads, the polishing head illustrated herein does not employ a retainer ring and/or a membrane in a polishing platen. As the pressure applied to the wafer 26 is given to the uniformly arrayed plurality of wafer holding cells 28 through the air bag 22 disposed between the first rotating head 21 and the second rotating head 23, the quickly rotating surface of the wafer 26 is polished. The air bag 22 controls the pressure applied to the wafer 26. The wafer holding cells 28 can hold and release the wafer 26. FIG. 2d schematically shows the reverse of FIG. 2c. Referring to FIG. 2d, the top view depicts the same pattern of the bottom surface of a wafer holding cell as FIG. 2e. FIG. 2e schematically shows the pattern of the bottom surface of a wafer holding cell 28. Thus, looking up at the bottom surface of an example wafer holding cell 28 as in FIG. 2e, we see several concentric circles representative of a conical funnel. The disclosed CMP polishing head and methods of use of the same reduce the substantial maintenance costs of consumables such as the retainer ring and membrane employed in prior art CMP polishing heads. In particular, the apparatus and methods disclosed herein avoid employing consumables such as the retainer ring and the membrane by providing the downward force used in polishing with an air bag while holding the wafer from the backside of the wafer with a vacuum. From the foregoing, persons of ordinary skill in the art will appreciate that the above disclosed methods and apparatus reduce the enormous maintenance cost associated with prior art polishing heads by eliminating the retainer ring and membrane used in the prior art. Further, the above disclosed methods and apparatus achieve improved polishing uniformity of the surface of a wafer. From the foregoing, persons of ordinary skill in the art will appreciate that the illustrated CMP polishing head holds and rotates a wafer with downward force to polish the surface of the wafer in a CMP process. The illustrated polishing head comprises a first rotating head to apply a downward force. The first rotating head is connected to a rotating axis. The illustrated polishing head also includes a second rotating head installed under and coupled with the first rotating head, an air bag positioned between the first and the second rotating heads to deliver the downward force from the first rotating head to the second rotating head, and a plurality of wafer holding cells to convey the downward force from the second rotating head to the wafer. The plurality of wafer holding cells is connected under the second rotating head and holds the wafer via a vacuum. The illustrated CMP polishing head may be used by holding a wafer by vacuum force with a plurality of wafer holding cells, performing a CMP process by providing downward force through the plurality of wafer holding cells while rotating the wafer, and releasing the vacuum force from the plurality of wafer holding cells when the CMP process is completed. Each wafer holding cell is coupled to a vacuum line and is connected with a second rotating head. It is noted that this patent claims priority from Korean Patent Application Serial Number 10-2003-0047495, which was filed on Jul. 12, 2003, and is hereby incorporated by reference in its entirety. Although certain example methods and apparatus have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents. | <SOH> BACKGROUND <EOH>As the integration of semiconductor devices increases, multi-layer interconnection technology has been put into practical use. Thus, local and global area planarization of an interlayer insulating layer has become important. A widely used CMP (Chemical Mechanical Polishing) method of polishing the surface of a semiconductor wafer employs chemical components contained in a slurry solution, a polishing pad, and a polishing agent. A CMP apparatus is most frequently used to polish the front face of a semiconductor wafer in fabricating semiconductor devices on the wafer. Generally, a wafer is planarized or softened at least one time during the fabricating process in order to make the surface of the wafer as flat as possible. In order to polish the wafer, the wafer is placed on a carrier, put into contact with a polishing pad covered with slurry and then pressed. Wafer polishing is then carried out by rotating the polishing pad and the wafer-loaded carrier. A prior art CMP apparatus for polishing a wafer includes a polishing platen, a polishing pad located over the polishing platen, a polishing head, and a retainer ring and/or membrane for holding the wafer in the bottom edge of the polishing head. The wafer is held in the retainer ring so that the surface of the wafer to be polished is disposed toward the polishing pad. The retainer ring has multiple grooves to facilitate the flow of polishing slurry to the surface of the wafer. The grooves are extended from the inner to the outer surface of the retainer ring. Each groove has a round shape structure. We will now look at the way in which the retainer ring and polishing pad are used in the prior art. To this end, FIG. 1 a through FIG. 1 c are schematic, cross-sectional, views which illustrate a retainer ring of a prior art polishing head. FIG. 1 a is a schematic, cross-sectional, view illustrating the structure of a prior art CMP polishing head 18 for polishing the surface of a wafer. FIG. 1 b and FIG. 1 c are schematic, cross-sectional, views which illustrate the retainer ring 14 . FIG. 1 c is a cross-sectional view of the channels 16 of the retainer ring 14 depicted in FIG. 1 b. Referring to FIG. 1 a , the prior art CMP apparatus has a polishing pad 10 which is covered with the flow of polishing slurry. It also has a polishing head 18 . The wafer 12 is positioned between the polishing pad 10 and the polishing head 18 . A retainer ring 14 is disposed at the bottom edge of the polishing head 18 . The retainer ring 14 holds the wafer 12 to prevent it from being derailed during the CMP process. The retainer ring 14 of the polishing head 18 has multiple grooves 16 to facilitate the flow of polishing slurry. The grooves 16 are extended from the inner surface of the retainer ring 14 to the outer surface of the retainer ring 14 . The slurry flows uniformly on the surface of the wafer 12 , since the grooves 16 act as passing channels to facilitate the flow of polishing slurry. FIG. 1 b is a cross-sectional bottom view of the retainer ring 14 . As mentioned above, the retainer ring 14 has multiple grooves 16 which extend from its inner surface to its outer surface. As shown in FIG. 1 b , the grooves 16 are circularly shaped and skewed at a predetermined angle toward the outer rim against the rotating direction of the retainer ring 14 . During a polishing process, the retainer ring 14 rotates with the desired speed and provides the whole area of the wafer 12 with a uniform flow of the polishing slurry through the grooves 16 . As shown in FIG. 1 c , the cross-sections of the channels 16 have a round shape 16 a . Thus, the channels 16 facilitate the smooth flow of polishing slurry over the surface of the wafer in comparison with the rectangular shape of grooves sometimes employed in the prior art. The worn amount of the polishing pad may be reduced by preventing fast sticking of the polishing pad, so that the durability of the pad can be increased. Conventional CMP polishing heads have employed consumables such as a retainer ring or membrane, but these consumables cause a huge increase in maintenance costs. Volodarsky et al., U.S. Pat. No. 5,803,799, describes a polishing head for polishing a semiconductor wafer. The polishing head includes a housing, a wafer carrier movably mounted to the housing, and a wafer retainer movably mounted to the housing. Quek et al., U.S. Pat. No. 6,245,193, describes a substrate carrier head for use in a CMP apparatus. Park et al., U.S. Pat. No. 6,336,846, describes a chemical-mechanical polishing (CMP) apparatus having a polishing head onto which a semiconductor wafer is fixed for holding the surface of the semiconductor wafer in contact with the surface of a polishing pad. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 a through FIG. 1 c are cross-sectional views which schematically illustrate the retainer ring of a prior art polishing head. FIG. 2 a through FIG. 2 e are cross-sectional views which schematically illustrate an example CMP polishing head. detailed-description description="Detailed Description" end="lead"? | 20040712 | 20060214 | 20050113 | 71729.0 | 0 | ACKUN, JACOB K | CMP POLISHING HEADS AND METHODS OF USING THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,889,407 | ACCEPTED | Regulation of endocrine and exocrine glands by means of neuro-electrical coded signals | A method and device for endocrine and exocrine gland control. The method comprises selecting neuro-electrical coded signals from a storage area that are representative of body organ function. The selected neuro-electrical coded signals are then transmitted to a treatment member, which is in direct contact with the body, and which then broadcasts the neuro-electrical coded signals to a specific endocrine and exocrine gland nerve or gland to modulate the gland functioning. A control module is provided for transmission to the treatment member. The control module contains the neuro-electrical coded signals which are selected and transmitted to the treatment member, and computer storage can be provided for greater storage capacity and manipulation of the neuro-electrical coded signals. | 1. A method for controlling endocrine and exocrine glands comprising the steps of: a. selecting from a storage area one or more waveforms generated in the body and carried by neurons in the body; b. transmitting or conducting the selected waveforms to a treatment member in contact with the body; and c. broadcasting the selected waveforms from the treatment member to an area in the body is affected to control endocrine and exocrine glands. 2. The method according to claim 1, in which step “a” further includes selecting said waveforms from a storage area in a computer. 3. The method according to claim 1, in which step “b” further comprises transmitting the selected waveforms remotely to the treatment member. 4. The method according to claim 1, in which step “b” further comprises seismic transmission of the selected waveforms. 5. An apparatus for controlling endocrine and exocrine glands, comprising: a. a source of collected waveforms generated in the body and indicative of endocrine and exocrine gland functioning; b. a treatment member adapted to be in direct contact with the body; c. means for transmitting one or more of the collected waveforms to the treatment member; and d. means for broadcasting the collected waveforms from the treatment member to an area in the body such that endocrine and exocrine glands are affected, thereby controlling endocrine and exocrine glands. 6. The apparatus according to claim 5, in which said transmitting means includes a digital to analog converter. 7. The apparatus according to claim 5, in which said source comprises a computer having collected waveforms stored in digital format. 8. The apparatus according to claim 7, in which said computer includes separate storage areas for collecting waveforms of different endocrine and exocrine gland functional categories. 9. The apparatus according to claim 5, in which the treatment member comprises an antenna for broadcasting endocrine and exocrine gland signals. 10. The apparatus according to claim 5, in which the treatment member comprises an electrode. 11. A method for controlling endocrine glands comprising the steps of: a. selecting from a storage area one or more waveforms generated in the body and carried by neurons in the body; b. transmitting or conducting the selected waveforms to a treatment member in contact with the body; and c. broadcasting the selected waveforms from the treatment member to an area in the body is affected to control endocrine glands. 12. The method according to claim 11, in which step “a” further includes selecting said waveforms from a storage area in a computer. 13. The method according to claim 11, in which step “b” further comprises transmitting the selected waveforms remotely to the treatment member. 14. The method according to claim 11, in which step “b” further comprises seismic transmission of the selected waveforms. 15. An apparatus for controlling endocrine glands, comprising: a. a source of collected waveforms generated in the body and indicative of endocrine gland functioning; b. a treatment member adapted to be in direct contact with the body; c. means for transmitting one or more of the collected waveforms to the treatment member; and d. means for broadcasting the collected waveforms from the treatment member to an area in the body such that endocrine and exocrine glands are affected, thereby controlling endocrine glands. 16. The apparatus according to claim 15, in which said transmitting means includes a digital to analog converter. 17. The apparatus according to claim 15, in which said source comprises a computer having collected waveforms stored in digital format. 18. The apparatus according to claim 17, in which said computer includes separate storage areas for collecting waveforms of different endocrine gland functional categories. 19. The apparatus according to claim 15, in which the treatment member comprises an antenna for broadcasting endocrine gland signals. 20. The apparatus according to claim 15, in which the treatment member comprises an electrode. 21. A method for controlling exocrine glands comprising the steps of: a. selecting from a storage area one or more waveforms generated in the body and carried by neurons in the body; b. transmitting or conducting the selected waveforms to a treatment member in contact with the body; and c. broadcasting the selected waveforms from the treatment member to an area in the body is affected to control exocrine glands. 22. The method according to claim 21, in which step “a” further includes selecting said waveforms from a storage area in a computer. 23. The method according to claim 21, in which step “b” further comprises transmitting the selected waveforms remotely to the treatment member. 24. The method according to claim 21, in which step “b” further comprises seismic transmission of the selected waveforms. 25. An apparatus for controlling exocrine glands, comprising: a. a source of collected waveforms generated in the body and indicative of exocrine gland functioning; b. a treatment member adapted to be in direct contact with the body; c. means for transmitting one or more of the collected waveforms to the treatment member; and d. means for broadcasting the collected waveforms from the treatment member to an area in the body such that endocrine and exocrine glands are affected, thereby controlling exocrine glands. 26. The apparatus according to claim 25, in which said transmitting means includes a digital to analog converter. 27. The apparatus according to claim 25, in which said source comprises a computer having collected waveforms stored in digital format. 28. The apparatus according to claim 27, in which said computer includes separate storage areas for collecting waveforms of different exocrine gland functional categories. 29. The apparatus according to claim 25, in which the treatment member comprises an antenna for broadcasting exocrine gland signals. 30. The apparatus according to claim 25, in which the treatment member comprises an electrode. | RELATED APPLICATIONS This is the non-provisional filing of application Ser. No. 60/486,089, filed Jul. 10, 2004, entitled “Regulation of Endocrine and Exocrine Glands By Means of Neuro-Coded Signals.” BACKGROUND OF THE INVENTION This invention relates to a device and method for regulation of endocrine and exocrine glands by means of neuro-electrical coded signals. Bodily homeostasis is the regulation of the milieu interieur (internal environment) of the living mammalian body. Homeostasis is the process through which organs, glands and the central and peripheral nervous system harmoniously function to balance life equilibrium. The process includes, but is not limited to, glandular participation in the regulation of body temperature, heart rate, respiration, digestion, energy metabolism, immunity and reproduction. Glandular secretions also are used to protect the human or animal body from invading microbes, environmental dust and other wind carried or propelled chemicals, smoke products or odors. The glandular flow of chemicals or hormones plays an important role in the homeostasis process. There are two principal classes of secretory glands. There are the “endocrine” glands that secrete directly into the blood stream also there are the “exocrine” glands that produces a secretion onto the surface of the body and to protect with secretions in the exterior orifices or into the interior of organs other than directly into the bloodstream. The ability to electrically cause the endocrine or exocrine glands to secrete or to cease secreting or even to partially secrete would be a compelling medical technology for potentially controlling or adjusting body homeostasis. The control of the glands is by means of neuro-electrical coded signals that originate in the brain and brain stem. The ability to influence the amount of chemicals, hormones or aqueous/mucoid substances to influence the body's response to stress, sexual function, lactation, tears, digestive juices, salt & water balance and behavior. Puberty is evolved in male and female mammals because of the long-term influence of endocrine glands. If such system of glands is controlled by actual neuro-electrical coded signals (waveform) generated by a device that records, stores and rebroadcast it would greatly add to the clinical medicine tools. Such glandular control technology would provide a clinical neuro-electric method to fine-tune the function of many glandular based biological systems for the benefit of mankind. The invention would use the actual neuro-electrical coded signals that send operational information to operate and regulate the wide variety of endocrine and exocrine glands of the human and animal body. Theses actual neuron signals travel along selected nerves to send the operational commands to the target gland. The glands of the human and other mammals are operated by neuro-electrical coded signals from the brain which, in turn can excrete, in selected cases, chemical instructional signals. These chemical signals are transferred to target organs via the blood stream in the case of the endocrine glands. The exocrine glands do not excrete into the blood stream as do the endocrine glands. These types of glands have a type of duct system to flow the secretions outward. The Exocrine glands excrete or secrete largely onto surfaces exterior to the body such as the sweat glands which help cool the body as a contribution to body homeostasis. The sebaceous glands lubricate the surface of the skin with an oily substance. The lacrimal glands make tears to cleanse and lubricate the eyes. Important exocrine glands are the mammary glands, which provide babies milk. The class of species called “mammals” gets their name because they nurse their young from mammary glands. Another type of exocrine glands are those that provide digestive chemicals such as saliva and digestive juices that affect the mouth, stomach and intestines to begin as the first step to accomplish the digestion of food. There are wax producing glands in the external ear canal for protection from insects and microbes. An example of an exocrine gland in a non-mammal species is the poison gland in snakes which is injected via fangs into a victim, which is usually a mammal, as an aid in catching food and to begin the digestive process. This is a representative sampling of the endocrine glands which can be regulated by neuro-electrical coded signals. These glands are ductless and transfer their secretory hormone products directly into the blood stream. The blood stream carries the endocrine hormones to distant cells or target organs within the body to control short or long-term functions. The following list is not meant to be complete or all encompassing, but to provide a picture of the arena in which the invention operates. Endocrine glands include the pituitary, thyroid, adrenal, parathyroid, ovary, testis and part of the pancreas. There is also the placenta, thymus and pineal gland. The prostate may be considered an exocrine gland. The lubricating vaginal canal mucous produced by the adult female in response to sexual stimulation can be considered an exocrine gland. The protective mucus produced in the bronchial tubes of the respiratory tract also qualifies as exocrine type. The kidney is also an excretory gland plus a vital organ. It produces hormones involved in the control of blood pressure and for erythropoiesis which is the production of red blood cells. The Kidney also functions as a vital organ filter to remove soluble waste products from the blood stream. Therefore the kidney is part a method to remove certain liquid waste and it is an endocrine gland too. The endocrine and exocrine glandular operating signal(s) occur naturally as a burst or continuous pattern of signals followed by a pause and then another burst of neuron activity followed by a pause of short or long duration and so it is on and on throughout life. Such signal(s) amplitude or time of pause can be varied to accomplish the glandular activity required. Endocrine and exocrine glandular activity requires variable repetitive neuro-electrical coded signals as humans or animals live. Various glandular secretions operate in a symphonic pattern being conduced by the brain to accomplish the mission assigned, all aimed at maintaining the best body homeostasis. There is adequate but variable space between the signals produced by the neurons located both in the brain and the peripheral nervous system to allow synchronization of secretion production into smooth hormonal or chemical applications by the endocrine and exocrine glands. SUMMARY OF THE INVENTION The invention provides a method for controlling endocrine and exocrine glands. Stored neuro-electrical coded signals that are generated and carried in the body are selected from a storage area. The selected waveforms are then transmitted to a treatment member which is in direct contact with the body. The treatment member then broadcasts the selected neuro-electrical coded signals to a muscle in the body. The neuro-electrical coded signals may be selected from a storage area in a computer, such as a scientific computer. The process of transmitting the selected neuro-electrical coded signals can either be done remotely or with the treatment member connected to a control module. The transmission may be seismic, electronic, or via any other suitable method. The invention further provides an apparatus for controlling endocrine and exocrine glands. The apparatus includes a source of collected neuro-electrical coded signals that are indicative of endocrine and exocrine glands functioning, a treatment member in direct contact with the body, means for transmitting collected waveforms to the treatment member, and means for broadcasting the collected neuro-electrical coded signals from the treatment member to the endocrine and exocrine glands. The transmitting means may include a digital to analog converter. The source of collected waveforms preferably comprises a computer which has the collected waveforms stored in digital format. The computer may include separate storage areas for collected neuro-electrical coded signals of different categories. The treatment member may be comprised of an antenna or an electrode, or any other means of broadcasting one or more neuro-electrical coded signals directly to the body. BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in greater detail in the following description of examples embodying the best mode of the invention, taken in conjunction with the drawing figures, in which: FIG. 1 is a schematic diagram of one form of apparatus for practicing the method according to the invention; FIG. 2 is a schematic diagram of another form of apparatus for practicing the method according to the invention; and FIG. 3 is a flow chart of the method according to the invention. DESCRIPTIONS OF EXAMPLES EMBODYING THE BEST MODE OF THE INVENTION For the purpose of promoting an understanding of the principles of the invention, references will be made to the embodiments illustrated in the drawings. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention illustrated herein being contemplated as would normally occur to the one skilled in the art to which the invention relates. Skin usually has a 1000 to 30,000 ohm resistance while the interior of the body is quite conductive. All coded signals operate at less than 1 volt, naturally. Applied voltage may be up to 20 volts according to the invention to allow for voltage loss during the transmission or conduction of the required coded signals through mylin nerve sheath or resistive fat and other material. Current should always be less than 2 amps output for the invention. Direct conduction into the nerves via electrodes connected directly to such nerves will likely have outputs of less than 3 volts and current of less than one-tenth of an amp. Up to 10 or more channels may be used simultaneously to exert medical treatment on glandular control to aid a patient in moving or performing muscular tasks suitable to his or her well-being as medical treatment. The invention encompasses both a device and a method for endocrine and exocrine gland control by means of neuro-electrical coded signals. One form of a device 10 for endocrine and exocrine gland control, as shown in FIG. 1, is comprised of at least one treatment member 12, and a control module 14. The treatment member 12 is in direct contact with a body and receives a neuro-electrical coded signal from the control module 14. The treatment member 12 may be an electrode, antenna, a seismic transducer, or any other suitable form of conduction attachment for broadcasting endocrine and exocrine gland signals that regulate or operate glandular function in human or animals. The treatment member 12 may be attached to efferent nerves leading to the endocrine and exocrine glands, afferent nerves leading to the brain or brainstem to accomplish modulation of glandular output, the cervical spine, the neck, or the endocrine and exocrine glands in a surgical process. Such surgery may be accomplished with “key-hole” entrance in a thoracic or limb stereo-scope procedure. If necessary a more expansive thoracotomy approach may be required for more proper placement of the treatment member 12. Neuro-electrical coded signals known to modulate endocrine and exocrine gland function may then be sent into nerves that are in close proximity with the brain stem or other parts of the brain. The control module 14 is comprised of at least one control 16, and an antenna 18. The control 16 allows the device to regulate the signal transmission into the body. As shown in FIG. 1, the control module 14 and treatment member 12 can be entirely separate elements allowing the device 10 to be operated remotely. The control module 14 can be unique, or can be any appropriate conventional device which can provide neuro-electrical coded signals for transmission to the treatment member 12. In an alternate embodiment of the device 10, as shown in FIG. 2, the control module 14′ and treatment member 12′ are connected. Similar members retain the same reference numerals in this figure. Additionally, FIG. 2 further shows another embodiment of the device 10′ as being connected to a computer 20, which provides greater capacity to store the neuro-electrical coded signals. The output voltage and amperage provided by the device 10′ during treatment shall not exceed 20 volts or 2 amps for each signal. The computer 20 is used to store the unique neuro-electrical coded signals, which are complex and unique to the endocrine and exocrine glands. It is a neuro-electrical coded-signal(s) selected from the stored library of neuro-electrical coded signals (waveforms) in the computer 20 which is transmitted to the control module 14′ and used for treatment of a patient. The waveform signals, and their creation, are described in greater detail in U.S. patent application Ser. No. 10/000,005, filed Nov. 20, 2001, and entitled “Device and Method to Record, Store, and Broadcast Specific Brain Waveforms to Modulate Body Organ Functioning,” the disclosure of which is incorporated herein by reference. The invention further includes a method, as shown in FIG. 3, for using the device 10, 10′ for endocrine and exocrine gland control. The method begins at step 22 by selecting one or more stored neuro-electrical coded signals from a menu of cataloged neuro-electrical coded signals. The neuro-electrical coded signals selected activate, deactivate, secrete, or adjust the endocrine and exocrine glands. Such neuro-electrical coded signals are similar to those naturally produced by the brain structures for balancing and controlling glandular processes. Once selected, the neuro-electrical coded signals may be adjusted, in step 24, to perform a particular function in the body. Alternatively, if it is decided that the neuro-electrical coded signals do not need to be adjusted, step 24 is skipped and the process proceeds directly with step 26. At step 26, the neuro-electrical coded signal is transmitted to the treatment member 12, 12′ of the device 10, 10′. Upon receipt of the neuro-electrical coded signals, the treatment member 12, 12′ broadcasts the neuro-electrical coded signals to the endocrine and exocrine glands or nerve location, as shown in step 28. The device 10, 10′ utilizes appropriate neuro-electrical coded signals to adjust or modulate glandular action via conduction or broadcast of neuro-electrical coded signals into selected nerves. Controlling endocrine and exocrine gland function may require sending neuro-electrical coded signals into one or more nerves, including up to ten nerves simultaneously. It is believed that target glands can only “respond” to their own individual neuro-electrical coded signal. In one embodiment of the invention, the process of broadcasting by the treatment member 12, 12′ is accomplished by direct conduction or transmission through unbroken skin in a selected appropriate zone on the neck, head, limb(s), spine, or thorax, or abdomen. Such zone will approximate a position close to the nerve or nerve plexus onto which the signal is to be imposed. The treatment member 12, 12′ is brought into contact with the skin in a selected target area that allows for the transport of the signal to the target nerve(s). In an alternate embodiment of the invention, the process of broadcasting the neuro-electrical coded signal is accomplished by direct conduction via attachment of an electrode to the receiving nerve or nerve plexus. This requires a surgical intervention as required to physically attach the electrode to the selected target nerve. Direct implantation on the nervous system of the selected endocrine and exocrine glands may be performed in order to transmit signals to control all or some glandular function. Such implantation can be presynaptic or post synaptic and may be attached to ganglion or nerve plexus associated with the desired secretion function. In yet another embodiment of the invention, the process of broadcasting is accomplished by transposing the neuro-electrical coded signal into a seismic form where it is sent into a region of the head, neck, limb(s), spine, or thorax in a manner that allows the appropriate “nerve” to receive and to obey the coded instructions of such seismic signal. The treatment member 12, 12′ is pressed against the unbroken skin surface using an electrode conductive gel or paste medium to aid conductivity. Various features of the invention have been particularly shown and described in connection with the illustrated embodiments of the invention. However, it must be understood that these particular products, and their method of manufacture, do not limit but merely illustrate, and that the invention is to be given its fullest interpretation within the terms of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates to a device and method for regulation of endocrine and exocrine glands by means of neuro-electrical coded signals. Bodily homeostasis is the regulation of the milieu interieur (internal environment) of the living mammalian body. Homeostasis is the process through which organs, glands and the central and peripheral nervous system harmoniously function to balance life equilibrium. The process includes, but is not limited to, glandular participation in the regulation of body temperature, heart rate, respiration, digestion, energy metabolism, immunity and reproduction. Glandular secretions also are used to protect the human or animal body from invading microbes, environmental dust and other wind carried or propelled chemicals, smoke products or odors. The glandular flow of chemicals or hormones plays an important role in the homeostasis process. There are two principal classes of secretory glands. There are the “endocrine” glands that secrete directly into the blood stream also there are the “exocrine” glands that produces a secretion onto the surface of the body and to protect with secretions in the exterior orifices or into the interior of organs other than directly into the bloodstream. The ability to electrically cause the endocrine or exocrine glands to secrete or to cease secreting or even to partially secrete would be a compelling medical technology for potentially controlling or adjusting body homeostasis. The control of the glands is by means of neuro-electrical coded signals that originate in the brain and brain stem. The ability to influence the amount of chemicals, hormones or aqueous/mucoid substances to influence the body's response to stress, sexual function, lactation, tears, digestive juices, salt & water balance and behavior. Puberty is evolved in male and female mammals because of the long-term influence of endocrine glands. If such system of glands is controlled by actual neuro-electrical coded signals (waveform) generated by a device that records, stores and rebroadcast it would greatly add to the clinical medicine tools. Such glandular control technology would provide a clinical neuro-electric method to fine-tune the function of many glandular based biological systems for the benefit of mankind. The invention would use the actual neuro-electrical coded signals that send operational information to operate and regulate the wide variety of endocrine and exocrine glands of the human and animal body. Theses actual neuron signals travel along selected nerves to send the operational commands to the target gland. The glands of the human and other mammals are operated by neuro-electrical coded signals from the brain which, in turn can excrete, in selected cases, chemical instructional signals. These chemical signals are transferred to target organs via the blood stream in the case of the endocrine glands. The exocrine glands do not excrete into the blood stream as do the endocrine glands. These types of glands have a type of duct system to flow the secretions outward. The Exocrine glands excrete or secrete largely onto surfaces exterior to the body such as the sweat glands which help cool the body as a contribution to body homeostasis. The sebaceous glands lubricate the surface of the skin with an oily substance. The lacrimal glands make tears to cleanse and lubricate the eyes. Important exocrine glands are the mammary glands, which provide babies milk. The class of species called “mammals” gets their name because they nurse their young from mammary glands. Another type of exocrine glands are those that provide digestive chemicals such as saliva and digestive juices that affect the mouth, stomach and intestines to begin as the first step to accomplish the digestion of food. There are wax producing glands in the external ear canal for protection from insects and microbes. An example of an exocrine gland in a non-mammal species is the poison gland in snakes which is injected via fangs into a victim, which is usually a mammal, as an aid in catching food and to begin the digestive process. This is a representative sampling of the endocrine glands which can be regulated by neuro-electrical coded signals. These glands are ductless and transfer their secretory hormone products directly into the blood stream. The blood stream carries the endocrine hormones to distant cells or target organs within the body to control short or long-term functions. The following list is not meant to be complete or all encompassing, but to provide a picture of the arena in which the invention operates. Endocrine glands include the pituitary, thyroid, adrenal, parathyroid, ovary, testis and part of the pancreas. There is also the placenta, thymus and pineal gland. The prostate may be considered an exocrine gland. The lubricating vaginal canal mucous produced by the adult female in response to sexual stimulation can be considered an exocrine gland. The protective mucus produced in the bronchial tubes of the respiratory tract also qualifies as exocrine type. The kidney is also an excretory gland plus a vital organ. It produces hormones involved in the control of blood pressure and for erythropoiesis which is the production of red blood cells. The Kidney also functions as a vital organ filter to remove soluble waste products from the blood stream. Therefore the kidney is part a method to remove certain liquid waste and it is an endocrine gland too. The endocrine and exocrine glandular operating signal(s) occur naturally as a burst or continuous pattern of signals followed by a pause and then another burst of neuron activity followed by a pause of short or long duration and so it is on and on throughout life. Such signal(s) amplitude or time of pause can be varied to accomplish the glandular activity required. Endocrine and exocrine glandular activity requires variable repetitive neuro-electrical coded signals as humans or animals live. Various glandular secretions operate in a symphonic pattern being conduced by the brain to accomplish the mission assigned, all aimed at maintaining the best body homeostasis. There is adequate but variable space between the signals produced by the neurons located both in the brain and the peripheral nervous system to allow synchronization of secretion production into smooth hormonal or chemical applications by the endocrine and exocrine glands. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention provides a method for controlling endocrine and exocrine glands. Stored neuro-electrical coded signals that are generated and carried in the body are selected from a storage area. The selected waveforms are then transmitted to a treatment member which is in direct contact with the body. The treatment member then broadcasts the selected neuro-electrical coded signals to a muscle in the body. The neuro-electrical coded signals may be selected from a storage area in a computer, such as a scientific computer. The process of transmitting the selected neuro-electrical coded signals can either be done remotely or with the treatment member connected to a control module. The transmission may be seismic, electronic, or via any other suitable method. The invention further provides an apparatus for controlling endocrine and exocrine glands. The apparatus includes a source of collected neuro-electrical coded signals that are indicative of endocrine and exocrine glands functioning, a treatment member in direct contact with the body, means for transmitting collected waveforms to the treatment member, and means for broadcasting the collected neuro-electrical coded signals from the treatment member to the endocrine and exocrine glands. The transmitting means may include a digital to analog converter. The source of collected waveforms preferably comprises a computer which has the collected waveforms stored in digital format. The computer may include separate storage areas for collected neuro-electrical coded signals of different categories. The treatment member may be comprised of an antenna or an electrode, or any other means of broadcasting one or more neuro-electrical coded signals directly to the body. | 20040712 | 20060606 | 20050113 | 74343.0 | 1 | ALEXANDER, JOHN D | REGULATION OF ENDOCRINE AND EXOCRINE GLANDS BY MEANS OF NEURO-ELECTRICAL CODED SIGNALS | SMALL | 0 | ACCEPTED | 2,004 |
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10,889,436 | ACCEPTED | Inflatable plush toy | A toy has an interior bag made of an airtight, flexible material, the configuration of which adapts closely to the shape of the toy in its final form. The bag includes an air valve, accessible from the outside and located in a place that is not easily visible, together with a closure cap, in order to facilitate the filling of the toy with air, or the expelling of the air, as desired. | 1. Inflatable plush toy comprising an exterior covering having an interior bag made of an airtight, flexible material, the configuration of the interior bag, in an expanded form, is shaped close to a shape of the toy in a final form, said bag including an air valve extending through the exterior covering and being accessible from outside the exterior covering and being located in a place that is not easily visible, said air valve including a closure cap to facilitate filling of the toy with air and expelling of the air from the toy. | PURPOSE The purpose of the invention protected by this Patent consists of an “Inflatable plush toy”. BACKGROUND Plush toys are grotesque figures, generally of animals, their essential characteristics being their softness to the touch and ease of elastic deformability. This latter property is achieved by their stuffing, consisting of a soft material (for example, polyester). At the present time, these toys are normally imported from countries with low-cost labour as, due to the high number of pieces comprising their morphology and the relative complexity of their assembly, the labour component of the cost of the toy is very high. Furthermore, the transportation of the goods from the country that manufactures them to the country marketing them is also a significant component of the cost, as these are items in which the volume/weight proportion is very high. In order to reduce the impact of the transportation cost on the price of the toy, occasionally (particularly when a relatively large size is involved) recourse is had to the purchase at source of the outside covering of the toy only, in order to stuff and close it in the country of destination. DESCRIPTION OF THE INVENTION The purpose of the invention comprising the object of this Patent consists of the elimination of the drawbacks of an economic nature that affect the manufacture and marketing of plush toys at the present time, according to the preceding description. For this purpose, an arrangement has been made for the outside covering of the toy to contain an internal bag made of an airtight flexible material (PVC, latex, etc.), the configuration of which adapts closely to the shape of the toy itself in its final form, with a conventional air valve on the bag accessible from the outside and located in a place that is not easily visible, together with its means of closure, in order to facilitate the filling of the toy with air, or the expelling of the air, as desired. With this arrangement, a number of cost advantages are obtained, which are claimed below: Elimination of the stuffing material. Elimination of the stuffing and closing operations. Reduction in the cost of freight and haulage. BRIEF DESCRIPTION OF THE DRAWINGS In order to supplement the description of the invention and facilitate the interpretation of the formal, structural and functional characteristics of its object, a drawing is attached, on which a sketch is made of the aspect of a preferred implementation of an “Inflatable plush toy”, which constitutes the object of this Patent, in a longitudinal cross-section view. DESCRIPTION OF A PREFERRED IMPLEMENTATION In order to clearly show the nature and scope of the advantageous application of the “Inflatable plush toy”, which constitutes the object of the invention claimed, its structure and the arrangement of its elements are described hereunder, making reference to the drawing, which, on representing a preferred implementation of the said object, on an illustrative basis, must be considered in the broadest sense and not as restricting the application and the content of the invention claimed. The exterior covering (1) of the toy has an interior bag (2) of an airtight, flexible material, the configuration of which adapts closely to the shape of the toy in its final form, while the said bag (2) includes a conventional air valve (3), accessible from the outside and located in a place that is not easily visible, together with its means of closure (4), in order to facilitate the filling of the toy with air, or the expelling of the air, as desired. | <SOH> BACKGROUND <EOH>Plush toys are grotesque figures, generally of animals, their essential characteristics being their softness to the touch and ease of elastic deformability. This latter property is achieved by their stuffing, consisting of a soft material (for example, polyester). At the present time, these toys are normally imported from countries with low-cost labour as, due to the high number of pieces comprising their morphology and the relative complexity of their assembly, the labour component of the cost of the toy is very high. Furthermore, the transportation of the goods from the country that manufactures them to the country marketing them is also a significant component of the cost, as these are items in which the volume/weight proportion is very high. In order to reduce the impact of the transportation cost on the price of the toy, occasionally (particularly when a relatively large size is involved) recourse is had to the purchase at source of the outside covering of the toy only, in order to stuff and close it in the country of destination. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>In order to supplement the description of the invention and facilitate the interpretation of the formal, structural and functional characteristics of its object, a drawing is attached, on which a sketch is made of the aspect of a preferred implementation of an “Inflatable plush toy”, which constitutes the object of this Patent, in a longitudinal cross-section view. detailed-description description="Detailed Description" end="lead"? | 20040713 | 20051101 | 20050616 | 94120.0 | 1 | MILLER, BENA B | INFLATABLE PLUSH TOY | SMALL | 0 | ACCEPTED | 2,004 |
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10,889,453 | ACCEPTED | Automated document cashing system | An automated document cashing system is provided with an automated machine that cashes monetary transaction documents such as checks, money orders, and that makes deposit entries into the bank account of the user after validation of the user and monetary transaction document, without the aid of a bank teller. Validation of the identity of the user is performed with the use of a card associated with intelligence that identifies the user. A biometric device also may be used in identifying the validity of the user. Validation of the document involves one or more of: validating the presence of a signature; validating the amount of the monetary transaction document including a manual entry of the amount by the user; validating CAR against the LAR; and validating the banking system parameters and rules for the customer and/or the transaction. To assist in the automatic analysis of data on monetary transactional documents or on remittance documents, the user is prompted to provide a bounding box about the data. An image touch screen may be touched by the user to locate the bounding box and the user may magnify the data to fill the boundary box to exclude other data from this analysis. After document and person validation, the system will dispense money or transfer monies to a savings account, a checking account, a smart card, or the like. The system will also write money orders or wire transfer money. By supplying monies in the form of cash, credit card authorization, smart card balance, or the like to the machine, the user can pay bills such as a utility bill through the system or purchase items dispensed by the system. | 1. An automated machine for an automated document handling system for dispensing cash to a system user comprising: a card receiver for receiving a card having an identification password associated therewith for identifying the user as a qualified user; a document receiver in the machine for receiving a document inserted by the system user into the machine for which cash is expected to be dispensed; a document scanner for scanning the received document; a processor for receiving the document scanner input and generating an image thereof; a display device coupled to the processor for displaying an image from the scanned document to the system user; an entering device coupled to the processor for the system user to enter an amount relative to the amount on the document; wherein the processor ascertains if an apparent signature from the document image is on the signature line of the document image in order to validate the document; and a cash dispenser coupled to the processor operable after the user has been qualified and the document has been validated by the processor to dispense cash automatically to the system user. 2. A machine in accordance with claim 1 further comprising: a MICR reader for reading a MICR amount line on the document and comparing the amount entered by the user to the amount read by the MICR reader. 3. A machine in accordance with claim 1 further comprising: an endorsement validator for interpreting an endorsement area of the stored image of the document to ascertain if an endorsement is present for validation of the document prior to completing the transaction. 4. A machine in accordance with claim 3 wherein the display device comprises a touch screen coupled to the processor, a bounding device operable by a touch on the screen to cause a magnification of the portion of the displayed document image being read to fill a larger area of the touch screen. 5. A machine in accordance with claim 4 further comprising: a manually operable acceptor coupled to the processor for the system user to signify acceptance by the user of the data identified as associated with the displayed bounding box. 6. A machine in accordance with claim 1 wherein the processor identifies a courtesy amount recognition (CAR) line and legal amount recognition (LAR) line of the document image; and based upon the likelihood of a match of the CAR amount relative to the LAR amount provides a validation of the document. 7. A machine in accordance with claim 1 wherein the document is a check and wherein a magnetic ink character recognition line (MICR) is on the check; said machine further comprising: a magnetic ink character reader coupled to the processor for magnetically reading that the MICR line region, the processor determining whether a genuine MICR is on the check, the processor further verifying that an account number and a bank number from the MICR line are valid prior to dispensing cash to the system user. 8. A machine in accordance with claim 7 wherein the processor causes the machine to prompt the system user to perform manipulations on the machine relative to the document being processed. 9. A machine in accordance with claim 8 wherein the evaluator of the processor is operated in a different mode in response to the user selecting a kind of document being processed from a list of several documents. 10. A machine in accordance with claim 8 wherein the processor responds to prompted user inputs is operable to locate data fields on the document image. 11. A machine in accordance with claim 10 wherein the document image is an image of a bill for payment. 12. A machine in accordance with claim 11 wherein the user is prompted to enter into the entry device the amount of the bill and amount to be paid from a check with a remainder of the check amount being dispensed to the user in cash; and a change device puts at least a portion of the remainder on a card of the user. 13. A machine in accordance with claim 12 wherein the image from the document includes: a user account number printed on the bill; the amount due; and the date of the bill. 14. An automated machine for an automated document handling system for dispensing cash to a system user comprising: a card receiver for receiving a card having an identification password associated therewith for identifying the user as a qualified user; a document receiver for receiving a document inserted by user into the machine for which cash is expected to be dispensed; a document scanner for scanning the document; a processor coupled to the document scanner for generating a document image; a display device coupled to the processor to display a scanned image from the document to the machine user; an entering device coupled to the processor for the system user to enter an amount relative to the document; wherein the processor interprets a courtesy amount recognition line (CAR) and a legal amount recognition line (LAR) on the document image; wherein the processor compares the CAR relative to the LAR and the amount entered by the system user relative to the LAR and CAR and provides a confidence level, the confidence level being compared to a threshold to validate the document and to cause a dispensing of cash; and a cash dispenser coupled to the processor operable after the processor qualifies the user and after the processor validates the document to dispense cash automatically to the system user. 15. A system in accordance with claim 14 wherein the system user provides a biometric input device coupled to the processor and a biometric identifier; and the processor evaluates the biometric identification from the user against stored biometric data relative to the user to qualify the user prior to dispensing cash to the user. 16. A method for automatic banking for dispensing cash to a system user without a teller, the method comprising the steps of: providing an automated machine having a card receiver; inserting a card having an identification password associated therewith identifying the user as a qualified user into the machine; inserting a document into the machine and scanning the document to produce a second document image; displaying an image from the scanned document to the machine user; entering by the user into the machine an amount relative to the amount on the document; reviewing the signature line of the document for the presence of a signature in order to validate the document; and dispensing from a cash dispenser in the machine after qualifying the user and validation of document. 17. A method in accordance with claim 16 wherein a MICR amount line appears on the document and including: reading the MICR amount line and comparing the amount entered by the user to the MICR amount read. 18. A method in accordance with claim 16 including: interpreting an endorsement area of the signature document image to ascertain if an endorsement is present for validation of the document prior to completing the transaction. 19. A method in accordance with claim 18 including: bounding data on the displayed document image and magnifying the displayed data being bounded to fill a display boundary area. 20. A method in accordance with claim 19 including: accepting from the user the bounded data to be processed. 21. A method in accordance with claim 16 including: interpreting a courtesy amount recognition (CAR) line and legal amount recognition (LAR) line from the second document image; and comparing the CAR relative to the LAR to provide a validation of the document. 22. A method in accordance with claim 16 wherein the document is a check and wherein a magnetic ink character recognition line (MICR) is on the check; further comprising: reading and verifying that the MICR line is written in magnetic ink; reading and verifying an account number and a bank number from the MICR; and verifying that the read bank and account numbers are valid prior to dispensing cash to the user. 23. A method in accordance with claim 22 including: prompting the user to perform manipulations on the machine relative to the document being processed. 24. A method in accordance with claim 23 including: selecting the kind of document being processed from a list of several documents being displayed to the user. 25. A method in accordance with claim 23 including: prompting the user to locate data fields on a document image; and bounding a data field on the document image for interpretation. 26. A method in accordance with claim 25 including paying a bill from the machine and an inserted check. 27. A method in accordance with claim 26 including: prompting the user to enter the amount of the bill and amount to be paid from a check with a remainder of the check amount being dispensed to the user in cash. 28. A method in accordance with claim 27 including: interpreting a user's account number printed on the bill; the amount due; and the date of the bill. 29. A method in accordance with claim 16 including the step of: writing change onto a card in addition to dispensing cash. 30. A method for handling documents and for dispensing cash to a user from a machine without a teller, said method comprising: inserting a card having an identification password associated therewith for identifying the user as a qualified user into the machine; receiving a document inserted by user into the machine in exchange for which cash is expected to be dispensed; scanning the inserted document; displaying a scanned image from the document to the machine user; manually entering by the user into the machine an amount relative to the document; machine interpreting a courtesy amount recognition line (CAR) and a legal amount recognition line (LAR) from the second document image; and matching the amount entered by the machine user to the interpreted LAR and CAR amounts; determining a confidence level; comparing the confidence level to a threshold to determine if it is sufficient to validate the document and to cause a dispensing of cash; and dispensing cash from the machine after qualifying the user and after validating the document. 31. A method in accordance with claim 30 including: taking biometric data from the user at the machine; and evaluating the biometric data from the user against stored biometric data relative to the user for qualifying the user prior to dispensing cash to the user. 32. An automated machine for an automated document handling system for making bank deposits with a monetary document comprising: a card receiver for receiving a card having an intelligence associated therewith for identifying the user as a qualified user; a document receiver in the machine for receiving the monetary document inserted by the system user into the machine from which a deposit is being made; a document scanner for scanning the received document; a processor for receiving the document scanner input and generating an image thereof; a display device coupled to the processor for displaying an image from the scanned monetary document to the system user; an entering device coupled to the processor for the system user to enter an amount to be deposited; the processor reviewing images from a legal amount recognition line and a courtesy amount recognition line for a confidence level for acceptance of the user-entered amount; the processor ascertaining if an apparent signature from the document image is on the signature line of the document image in order to validate the document; and an acceptance of deposit indicator operable by the processor after qualification of the user and validity of the document to indicate proof of deposit to the system user. 33. A machine in accordance with claim 32 further comprising: a MICR reader for reading a MICR amount line on the document and comparing the amount entered by the user to the amount read by the MICR reader. 34. A machine in accordance with claim 32 wherein a locating device is provided to define coordinates on the image and the device is operable by the user to locate areas on the document image for the processor to review. 35. A machine in accordance with claim 32 wherein the device comprises a touch screen and the user touches the screen at areas on the document image for one or more of the CAR line, LAR line, date line, MICR line, name line and address line. 36. A machine in accordance with claim 35 wherein the processor comprises an arbitrator for comparing results from an analysis of the CAR line, LAR line, and the user-entered amount. 37. A machine in accordance with claim 32 comprising ICR engines that specialize in recognition of a particular portion of the document image; a CAR engine that provides confidence levels with respect to the CAR line; and a LAR engine that provides confidence levels with respect to the CAR line. 38. A method of making bank deposits with a monetary transaction document in an automated system without the use of a teller, the method comprising the steps of: providing an automated machine having a card receiver for receiving a card having an intelligence associated therewith for identifying the user as a qualified user; inserting a monetary transaction document into the automated machine; scanning the received document and generating an image therefrom; displaying an image from the scanned monetary transaction document to the system user; entering an amount by the user into the machine, which amount is to be deposited; reviewing images from a legal amount recognition line and from a courtesy amount recognition line and reviewing the user-entered amount in a processor to provide a confidence level; ascertaining if an apparent signature from the document image is on the signature line of the document image in order to validate the document; and providing an acceptance of deposit to the user operable by the processor after qualification of the user and an acceptable confidence level with respect to the document. 39. A method in accordance with claim 38 further comprising the further step of: reading a MICR amount line on the document and reviewing the amounts entered by the user and read by a MICR reader to ascertain if a sufficient confidence level is present. 40. A method in accordance with claim 38 including the further step of: defining coordinates on the image by user and locating areas on the document image for the processor to review. 41. A method in accordance with claim 38 including the further step of: providing a touch screen, touching the screen at areas on the document image for one or more of the CAR line, LAR line, date line, MICR line, name line and address line. 42. A method in accordance with claim 41 including the further step of arbitrating results from an analysis of the CAR line, LAR line, and the user-entered amount. 43. A method in accordance with claim 38 including the step of: using ICR engines that specialize in recognition of a particular portion of the document image; using a CAR engine that provides confidence levels with respect to the CAR line; and using a LAR engine that provides confidence levels with respect to the LAR line. 44. A method in accordance with claim 38 including the step of: reviewing a MICR line on the monetary transaction document; and reviewing a date on the transaction for meeting rules with respect to antedating or post-dating. 45. A method in accordance with claim 38 including the step of: dispensing in cash a portion of the amount to the user from the amount being deposited; and writing any change from the portion being dispensed onto a card of the user. 46. An automated banking system for receiving cash from a user and for dispensing cash to a user comprising: an automated machine having a card receiver for receiving a card which assists in identifying a user as being qualified to perform transactions with the machine; a document receiver for receiving a monetary transaction document to be cashed; a device for interpreting the amount on the monetary transaction document; a signature analyzer for analyzing that a signature is present at the desired position on the monetary transaction document; a cash dispenser in the automated machine for dispensing cash to the user; an entering device for the user to enter the amount of the monetary transactional document; a cash receiver for receiving cash and a cash analyzer for analyzing the amount of cash received from the user; a cash storage device associated with the machine for receiving the cash being deposited by the user; and a transactional operator for operation by the user to cause a dispensing of cash to the user or to perform a transaction upon deposit of sufficient cash by user for the requested transaction. 47. A system in accordance with claim 46 wherein: the document being cashed is a money order. 48. A system in accordance with claim 46 wherein: the transaction is payment of a bill from a provider; the device for interpreting the amount includes a scanner to scan the provider's account number and the user's identification from the bill. 49. A system in accordance with claim 48 wherein: the cash receiver adds the cash bills received and forwards signals representing the total cash being deposited; and a comparator compares the cash being deposited relative to the amount scanned from the bill by the scanner to ascertain if the total cash covers the bills and a transaction fee. 50. A method of automated banking for receiving cash from a user or for dispensing cash from the machine to the user comprising: providing an automated machine having a card receiver for receiving a card, which assists in identifying the user as being qualified to use the machine; inserting a signed monetary transactional document into the machine; providing a cash dispenser for dispensing cash to the user operable if needed; depositing cash into the machine and automatically calculating the amount of cash which is being deposited into the machine; analyzing the monetary transaction document for the presence of a signature; entering manually by the user the amount of the monetary transaction document; inquiring of the user what transaction is to be performed with the deposited cash or from the signed monetary transaction document; and automatically deducting a fee for the transaction and displaying to the user the amount of the transaction fee. 51. A method in accordance with claim 46 further comprising: inserting a document to be cashed into the document receiver; reading the cursive signature on the document; verifying the signature as a qualified signature; and dispensing cash to the user. 52. A method in accordance with claim 50 further comprising: paying a bill by inserting the bill into the machine; ascertaining the bill provider's account number and user's identification account number from the bill; and sending signals over a network to cause a transfer of funds to the account of the bill provider. 53. A method in accordance with claim 50 further comprising: recording the transaction on a storage medium; and issuing a receipt to the user with a receipt printer. 54. A method in accordance with claim 50 further comprising: generating change between the amount of transaction and the amount of cash or the amount written on through the medium; and further comprising writing change onto a card for the user. 55. A method of operating an unattended banking machine for performing a number of banking transactions and other transactions by a user, comprising: providing an automated machine having a card receiver for receiving a card which identifies the user as being qualified to use the machine; displaying to the user a list of selected, transactional options including withdrawal of cash option, a deposit of cash option, a cashing check option, a cashing money order option, a buying money order option, a wire transfer screen option, a bill payment option and purchasing option; receiving a card and verifying the user as being qualified; depositing a monetary transaction document in the machine, and scanning the monetary transaction document being deposited with respect to the amount on the document and for the presence of a signature on the document; dispensing cash to the user if the user is entitled to cash and if the document and the user meet sufficient security confidence levels; and printing a document showing the transaction, and fees for the transaction, and the amount of cash or being dispensed or deposited in the machine. 56. A method in accordance with claim 55 wherein the user selects a dispensing and purchasing option and further comprising: reviewing the amount of cash deposited by the user with respect to the item being purchased; and dispensing the item to the user through the machine upon verification of sufficient payment by the qualified user of the machine. 57. A method in accordance with claim 55 including the step of: displaying on a display screen various transactional options; and manually selecting one transaction to be performed from the list of transactional options available to the user. 58. A method in accordance with claim 55 wherein the document is a check and further comprising: reading the magnetic ink character recognition data with respect to the bank issuing the check; and communicating through the communication network to the identified bank. 59. A method in accordance with claim 55 wherein the document being received is a money order, and further comprising examining a cursive signature on the back of the money order prior to validation and dispensing of any cash to the user. 60. A method in accordance with claim 55 wherein the user has selected a bill paying operation further comprising: receiving the bill document; scanning the bill document for the amount due to the provider; communicating the modem to the bill issuer's bank account the amount of payment being made by the user; generating a receipt showing an amount paid for the bill to the user; storing the bill in a storage device; and providing a transactional tag with respect to the bill so that the transaction can be later reviewed, if necessary. 61. A method in accordance with claim 55 further comprising: storing money order blanks in the machine; generating signals to cause a printer to print the amount to be paid on the money order; and dispensing the printed money order to the machine user. 62. A method in accordance with claim 55 including the step of: performing a biometric analysis of a biometric characteristic of the user relative to a previously stored biometric characteristic of the user for qualifying the user. 63. A method in accordance with claim 55 including the step of: prompting the user to provide a bounding box about a scanned portion of the monetary transaction document. 64. A method in accordance with claim 63 including the step of: touching a touch screen in response to a prompting. 65. A method in accordance with claim 64 including the step of: magnifying date within the boundary box to aid in elimination of unwanted data. 66. A system for automatic cashing of checks or making remittance transactions without the aid of bank teller or the like, comprising: an automated machine for receiving a document having data thereon for the transaction; a scanning device in the machine for scanning the document and providing an image from the document to the user; a user validator for validating the user with a security confidence level; a document validator for validating the document with a security confidence level; a manual entry device operable by the user to enter an amount with respect to the document and the transaction to be performed; a cash dispenser associated with the machine for dispensing cash when the user and document have sufficient security confidence levels; and a boundary device operable by the user to locate data on the transaction document for automatic analysis. 67. A system in accordance with claim 66 wherein: the boundary device includes a user operated magnification to magnify the data in a bounding box. 68. A method in accordance with claim 67 wherein: a touch screen is touched by the user to create the bounding box and to magnify the data in the bounding box. 69. A system for automatic cashing of checks or making remittance transactions without the aid of bank teller or the like, comprising: an automated machine for receiving a document having data thereon for the transaction; a scanning device in the machine for scanning the document and providing an image from the document to the user; a user validator for validating the user with a security confidence level; a document validator for validating the document with a security confidence level; a manual entry device operable by the user to enter an amount with respect to the document and the transaction to be performed; a cash dispenser associated with the machine for dispensing cash when the user and document have sufficient security confidence levels; and a card writing device for adding a change amount onto a card to complete the transaction. 70. An apparatus in accordance with claim 69 wherein the cash dispenser comprises bins for holding only cash of certain large denominations; and a processor in the system causes the dispensing of large denominations of cash from the bins and a dispensing of the card after writing the smaller change amount on the card. 71. A system for automatic cashing of checks or making remittance transactions without the aid of bank teller or the like, comprising: an automated machine for receiving a document having data thereon for the transaction; a scanning device in the machine for scanning the document and providing an image from the document to the user; a user validator for validating the user with a security confidence level; a document validator for validating the document with a security confidence level; a manual entry device operable by the user to enter an amount with respect to the document and the transaction to be performed; a cash dispenser associated with the machine for dispensing cash when the user and document have sufficient security confidence levels; and the validator for the user includes a biometric device for analysis of a biometric characteristic of the user. 72. An apparatus in accordance with claim 71 wherein the validator for the document includes an engine for extraction of data at a legal amount recognition line (LAR) and an engine for extraction of data at a courtesy amount recognition line (CAR) to provide security confidence levels that CAR and LAR match one another. 73. A system for automatic cashing of checks or making remittance transactions without the aid of bank teller or the like, comprising: an automated machine for receiving a document having data thereon for the transaction; a scanning device in the machine for scanning the document and providing an image from the document to the user; a user validator for validating the user with a security confidence level; a document validator for validating the document with a security confidence level; a manual entry device operable by the user to enter an amount with respect to the document and the transaction to be performed; a cash dispenser associated with the machine for dispensing cash when the user and document have sufficient security confidence levels; and a MICR device for analysis of a MICR line with respect to the amount of a payroll check being cashed; and a document validator comprises a device for analysis of the check issuer's account number as authorized account. 74. A system in accordance with claim 73 wherein the document validator comprises a MICR reader to detect that the MICR line is written with magnetic material. 75. A method for automatic cashing of checks or making remittance transactions without the aid of bank teller or the like, comprising the steps of: providing an automated machine for receiving a document having data thereon for the transaction and a processor for the system; scanning the document and providing an image from the document to the user; validating with the processor that the user has a sufficient security confidence level; validating with the processor the document as having a sufficient security confidence level; operating a manual entry device at the machine to enter an amount with respect to the document and the transaction to be performed; and bounding data on the transaction document by operations of the user to locate data for the processor for an automatic analysis by the processor; and dispensing cash when the user and document have validated security confidence levels. 76. A method in accordance with claim 75 including the step of: magnifying the data in the bounding box. 77. A method in accordance with claim 76 including the step of: touching a touch screen to create the bounding box and to magnify the data in the bounding box. 78. A method for automatic cashing of checks or making remittance transactions without the aid of bank teller or the like, comprising the steps of: providing an automated machine for receiving a document having data thereon for the transaction and a processor for the system; scanning the document and providing an image from the document to the user; validating with the processor that the user has a sufficient security confidence level; validating with the processor the document as having a sufficient security confidence level; operating a manual entry device at the machine to enter an amount with respect to the document and the transaction to be performed; and dispensing cash when the user and document have validated security confidence levels in bills of certain denominations; and writing change on a card of the user to complete the cash transaction. 79. A method in accordance with claim 78 wherein the cash dispenser comprises bins for holding only cash of certain large denominations; and including the step of: operating the processor to cause a dispensing of the large denominations of cash from the bins; and dispensing of the card from the machine after writing the smaller change amount on the card. 80. A method for automatic cashing of checks or making remittance transactions without the aid of bank teller or the like, comprising the steps of: providing an automated machine for receiving a document having data thereon for the transaction and a processor for the system; scanning the document and providing an image from the document to the user; validating with the processor that the user has a sufficient security confidence level; validating with the processor the document as having a sufficient security confidence level; operating a manual entry device at the machine to enter an amount with respect to the document and the transaction to be performed; and analyzing a biometric characteristic of the user as part of the validation of the user; and dispensing cash when the user and document have validated security confidence levels. 81. A method in accordance with claim 80 including the steps of: using an engine for extraction of data at a legal amount recognition line (LAR) and using an engine for extraction of data at a courtesy amount recognition line (CAR) to provide security confidence levels that CAR and LAR match one another. 82. A method for automatic cashing of checks issued by a previously authorized issuer entity without the aid of bank teller or the like, comprising the steps of: providing an automated machine for receiving a document having data thereon for the transaction and a processor for the system; scanning the document and providing an image from the document to the user; validating with the processor that the user has a sufficient security confidence level; validating with the processor the document as having a sufficient security confidence level; operating a manual entry device at the machine to enter an amount with respect to the document and the transaction to be performed; and reading a MICR line to establish the cash amount of the monetary transaction document generated by the authorized issuer; analyzing the issuer's account number as being an authorized account for the issuer entity; and dispensing cash when the user and document have validated security confidence levels. 83. A method in accordance with claim 82 comprising: detecting that the MICR line is written with magnetic material. 84. A method for automatic handling of checks without the aid of bank teller or the like, comprising: providing an automated machine for receiving a document having data thereon for the transaction and a processor for the system; scanning the document to produce a document image and dissecting the image; entering the check amount by the user; validating with a processor that the user has a sufficient security confidence level; performing several field evaluations from the dissected image with respect to the amount of the check; making a list of amount results ranked by confidence level from a plurality of field evaluations; providing rules for arbitration of the check transaction; arbitrating a transaction in response to the user-entered check amount and the respective field amount results using the rules; and performing the transaction when the transaction arbitration has been satisfied. 85. A method in accordance with claim 84 wherein performing several field evaluations includes: extracting a dissected image of a legal amount recognition line (LAR) and extracting a dissected image of a courtesy amount recognition line (CAR). 86. A method in accordance with claim 84 further comprising: making a remittance transaction with the check; dissecting an image of an associated remittance document; making a list of amount results ranked by confidence level with respect to the amount on the associated remittance document; and providing the amount results of the associated remittance document for arbitration prior to making the remittance transaction. 87. A method in accordance with claim 85 wherein performing the transaction comprises the step of: making a deposit in the user's account. 88. A method in accordance with claim 84 wherein making several field evaluations comprises: optically recognizing a MICR line amount; and extracting a dissected image of a date amount recognition line. 89. A method in accordance with claim 85 wherein the arbitration step comprises: inputting a CAR recognition result into a weighted confidence algorithm for the CAR; comparing the result of the weighted confidence algorithm with a CAR threshold value; inputting a LAR recognition result into a weighted confidence algorithm for the LAR; and comparing the result of the weighted confidence algorithm for the LAR with a CAR threshold value. 90. A method in accordance with claim 84 comprising: magnetically recognizing a MICR line on the check to establish that the MICR line is written with magnetic material; and performing a date amount recognition. | CROSS-REFERENCE TO RELATED APPLICATION This is a continuation-in-part of copending U.S. application Ser. No. 08/866,139, filed May 30, 1997. BACKGROUND OF THE INVENTION The invention relates to automated banking systems and machines including those which employ or are an improvement over automatic teller machines (ATMs). The invention also relates to providing such ATMs with sufficient security confidence levels with respect to the user, to the document, and to the bank parameters and rules that cash can be securely dispensed to the user as a result of the cashing of payroll or third party remittances or the paying of bills. The confidence levels should be such as would normally be achieved or approach those in comparable transactions with a teller. A number of security problems arise with the addition to ATMs of functions performed by full service banks and currency exchanges. Such functions include cashing checks and money orders, paying bills, or handling a cash equivalent transaction, such as making a deposit into a bank account. When the bank is to cover such checks and dispense cash to the user, the bank requires validation of the user identity, validation of the genuineness of the document, validation of the amount(s) set forth on the document, validation of a signature on the document, validation of an endorsement when needed, validation of the bank parameters or rules, etc. To date, ATMs have been unable to provide such validations with a reliability sufficient to cash many documents without the presence of a teller. To provide an acceptable confidence level to the bank with respect to user validation prior to dispensing cash, a minimum requirement is the use of an ATM card, smart card, or the like, and a password such as a PIN number. The machine could read these, as in conventional machines. In accordance with the preferred embodiments of the present invention, a biometric check also is provided to assure that the person using the machine is a qualified user. This involves extracting recognition features from the user and preferably biometric features such as voice characteristics or features, facial recognition features, retinal features; fingerprint features, palm features; and/or signature features or the like. The qualified user will have previously provided such features to the bank system where they are stored for comparison to the extracted features of the person using the machine. The results comparison must reach certain confidence levels that can be set and/or adjusted by the bank to its satisfaction. Thus, if provided with confidence threshold levels as to card, password and/or the biometric features, the bank can be reasonably assured that the AIM user is a qualified user. With respect to document validation including the amount of document such as the pay amount of the remittance, a number of validation techniques are desired. To assure that the document being cashed is the original and not merely a photocopy of a valid check having a MICR line thereon, the MICR line should be tested to ascertain that a sufficient magnetic field is present at the MICR line position. Another validation that is desired is a reading of the MICR line contents and communicating to the banking system that a bank number and an account number for the identified bank refer to a real rather than a fictitious bank or account. Additionally, for checks, it is desired to be able to read the CAR amount and the LAR amount and to compare the same to detect whether or not the CAR line has been changed, for example, a “1” has been changed to a “4” or a “7” by merely adding pen strokes to the “1”. Other validations can be used and obtained to guard against violation of bank parameters or rules. Another significant document validation procedure with respect to checks is a determination that a signature is present. That is, the check is signed at the signature line. Going even further, it would be helpful to establish some acceptable signature confidence level by comparison of the signature against a stored signature of the user in instances where the user is signing a check or endorsing the back of the check. Also, in transactions where the check needs to be endorsed, there should be a validation by the machine that a signature is present at the endorsement line. Also, there may be a step of comparing a signature against a stored signature of the endorser. When improper payments are made to the user if the transactional is fraudulent, it is an important security feature to be able to prove that the user had an intent to defraud the bank. Absent such proof of fraudulent intent, the user may escape civil or criminal liability by claiming that such improperly dispensed cash or cash equivalent was a solely due to the fault of the ATM or banking system and not attributable to the user. That is, the user may claim he did not intentionally cause the cash dispensed or dispensed in an amount to be larger than that to which he was entitled and that there was no culpability on his part for the amount of cash dispensed to him. The wide variety of checks, money orders and bills presents a still further problem with transactions involving cashing of checks or the like, depositing funds to an account, or paying bills. As to each document, the location of the data fields to be analyzed may be different. Preferably, the ATM machine should be able to process large amount payroll checks, smaller amount personal checks, and bills having a bill pay amount located at various places on the bill. Preferably, a cash or cash equivalent dispensing system used without a human teller also is able to meet various bank parameters or rules. Often there is a transaction maximum limit, which may be customized as to the drawer of the check issuer or the payee. The bank may have cash payout limits on a daily or other time basis that should be met with sufficient confidence before dispensing cash. The bank may also have check date rules with respect to processing antedated or post-dated checks that should be satisfied. Finally, the bank may want to set its own thresholds with respect to confidence levels with respect to the identity of the user and validation of document. The system should be able to meet the satisfaction levels desired by the bank, and to be able to adjust such levels for a given transaction, type of transaction, or different validations. Another consideration for transactions such as cashing checks, paying bills, or other like things from a remote banking machine is the need to make a record and to leave an audit trail for later manual review, if required, of the transaction. Among some of the mechanical problems that have been experienced with the remote ATM-type machines is that of providing change in coins or small bills. Already, over a single weekend, ATMs are being severely taxed often to the point that they are completely emptied of their cash contents. In addition, ATMs do not have change makers. When cashing checks, money orders or returning change from a cash bill payment, the ATM must be able to return to the user the exact amount. If the exact amount is in cash, the addition of a coin change maker and small denomination bill dispenser adds considerable expense and maintenance problems to the machine. This would be necessitated to provide the exact change, including coins, to the user who is cashing a check or performing some other function, such as paying a bill with cash from which change is due. The situation is aggravated when the ATM is performing transactions that include an automatic fee calculation and deduction of the fee because there will usually be change due for any cash payout after the transaction fee deduction. Another problem with providing a commercially practical automated banking machine is that of the time needed for the transactions. Preferably, the transactions should be relatively brief and simple so that a minimal number of operator actions, such as touch screen pushes or keystrokes, are required for each transaction. If a particular transaction takes more than a minute or two, the system would probably be too slow to adequately service a line of people waiting to use the machine at a busy time, for instance on a weekend. Also, if the machine is able to process a large number of different types of transactions like those of a full-service bank or a currency exchange, the machine should provide the user a wide range of funds-delivery or payment options so that the payment can be made in cash, by credit card, by smart card, or by withdrawal from a checking or savings account. Even if an ATM existed for paying bills or processing checks of various amounts, that ATM might have difficulty in automatically locating, reading or interpreting amount lines such as the CAR or LAR, an invoice account number, the amount of the invoice, the amount to be paid, etc. without assistance from the user. Often the numbers written, typed or printed in such lines are relatively small. They might need to be accurately separated from any other writing or numbers to provide a secure and accurate execution of the desired transaction for the document being read. To this end, there is a need for an efficient system or method to locate, read, and interpret such lines with a manual input from the user. There is a need for an automatic banking machine which includes an ATM-like machine that performs and allows a number of service options, such as for example the withdrawing of cash, the deposit of cash, the cashing of a check, the cashing of a money order, the purchase of a money order, the transfer of funds by wire, payment of a bill and purchase of end user items. SUMMARY OF THE INVENTION In accordance with the present invention, there is provided an automated banking system including one or more machines which perform the usual ATM functions, but also have such significant security safeguards that they allow the cashing of monetary transaction documents such as checks or money orders, or handling of cash equivalent transactions such as making a deposit in the bank account of the user, without the aid of a teller. These functions are achieved by having sufficient validation of the identity of the user, validation of document, such as being a signed or endorsed check or the like, validation of the amount to be paid in cash or deposited, and validation of the banking system parameters or rules for the customer and/or transaction. With respect to validation of the personal identity of the ATM user, a first, minimal fraud protection procedure is to verify that the ATM card and/or the user, as presented at the machine, is associated with a qualified password or PIN number that, upon entry, validates the user as a qualified user. Preferably, and in accordance with the invention, an additional biometric comparison or recognition function is made between extracted features of the user such as face features, voice features, retina features, fingerprint features, palm features, handwriting features for signature verification, etc. In the present invention, the identity of the user is preferably validated with sufficient levels of confidence that cash will be dispensed if the other validation techniques are also satisfied. The bank will have its own rules with respect to how large a transaction will be permitted for the particular user, particularly with respect to the dispensing of cash to the user. In the preferred embodiment of the invention, the validation of the document preferably includes the extraction of data to compare the LAR amount and the CAR amount. In instances where the check to be negotiated includes a magnetic ink character recognition (MICR) line amount for the amount of the check, the MICR line may be read and a comparison of the LAR to the CAR is not needed. Additionally, other validation methods for checks may be provided and practiced such as validation that magnetic ink is present on the MICR line and that bank and account numbers are recognized as being valid within the banking system computer system. To prove that the user intentionally requested the amount of cash being dispensed, the user must manually enter amounts using a manual entry device at the ATM, e.g., the pay amount of the check, so that user will not be able to contend later that a machine error caused a specific payment to him. A part of the proof of the intentional request yielded by scanning the check and presenting a computer-generated image of the check to the user and prompting the user to enter the payable amount via an entry device. A still further validation technique is used in the preferred embodiment of the invention to safeguard the assets of the bank. Banks may have their own set of parameters or rules governing payouts and other transactions that must be validated. For example, validation techniques are used to assure that the amount of cash being paid out is equal or less than the transaction or daily limit for the user and the bank is satisfied with paying out those amounts based on credit history of user. In accordance with a further aspect of the invention, the bank will receive a validation that a signature is present at the signature line of the document, such as a check, before performing the requested financial transaction with respect to the check. To this end, the signature line is located and an analysis is made to an acceptable confidence level that a signature is present at the signature line. If a signature is lacking, the check will be rejected. Preferably, an analysis will be made as to verify the user's signature against stored user signatures to provide an additional security check to provide further confidence to the bank doing the transaction. Machine protection against a skilled forgery is difficult with current technology; nonetheless, unskilled forgeries or ambiguous signatures may still be detected. In instances where a third-party check or money order is to be processed and the ATM user must endorse the instrument, it is preferred to locate the endorsement line and at least validate that an endorsement is present in order to protect the receiving bank and others in the check reconciliation process against certain types of claims. Again, if the user has signatures of record, the endorsement can be compared to the signatures of record and a confidence level validation can be achieved if the transaction is to be completed. In the preferred ATM machine, the user manually selects the transaction, for instance from a list of transactions including check cashing, check deposit, bill payment, etc. The user then further operates the machine by inserting the document into the machine to cause a computer generated image to be seen by the user and to allow for analysis of features of the document image reflective of the document's contents. Because of the wide variety of document sizes and the variety of locations of the amount line or lines such as CAR, LAR or bill payment due, it is preferred to prompt the user to locate the coordinates of and/or to bound one or more fields for analysis and validation. These fields may include a date field, a CAR field, a LAR field, an amount field, an account number or MICR line field. If the document fails to meet the threshold validity for any one or more of these bounded fields, further transaction processing is aborted without any cash being dispensed to the user. In accordance with a further aspect of the invention, the ATM user is prompted by the display and the display provides a bounding box image. The bounding box can be adjusted by the user who then accepts or rejects with respect to a particular line. The accepted line in the bounding box is machine interpreted by OCR or some other image processing technique or the like. Typically, account numbers for bills and the amount of the bill to be paid are located often arbitrarily at various places. They are difficult to locate and must be precisely delineated from other adjacent typing, printing, letter or cursive to allow the transaction to be accomplished. In a preferred embodiment of the invention, the user is prompted to touch a touch screen display at the desired location, e.g., the account number on an invoice. The user then has the option of “tweaking” or adjusting the bounding box to cover only the desired information. The user is prompted to point to the general area of the document image that contains the information, such as an account number or an amount, to be bounded. The identified region would have its image zoomed on the screen. The first zoom step might be 1.8× linear magnification with the next step 1.1×. The magnification factor would decrease for each additional step to help avoid zoom overshoot. When zooming has been completed, the user would so indicate to the machine and then would be prompted to define the bounding box. This would be done in part by pointing to the beginning and the end of the area of interest. After this first bounding box is generated, a pixel analysis routine would be executed in the pixels at the bounding box borders. This would help ensure that no stray or extraneous characters were inadvertently included in the bounding box leading possibly to a spurious result from later analysis of the data contents of the bounding box. Finally, the user would indicate her acceptance or rejection of the final bounding box, which might change color for clarity, by appropriate keystrokes or touch screen entries or the like. This technique would avoid problems of lack of bounding box resolution due to a user's finger obscuring a feature of interest during box definition. An alternative bounding box technique would require the user to trace her finger around the region of interest thereby enclosing it rather than simply identifying the beginning and the end of the field. In order to assist the user the ATM provides prompts to the user and has buttons or touch screen areas that allow the user to switch back to the menu screen to begin again. In the alternative they would allow the user to undo the current screen and go back one screen to make a revision or the like where appropriate. When processing a monetary transaction document for routine bill paying, it is preferred to provide a validation of the bill, the user and the monetary transaction document being used to pay the bill or a portion thereof. With a bill-paying transaction, an operative assumption may be made that where no cash or cash equivalent is being paid out to the user, that user lacks an incentive to misrepresent the pay amount on the checks or the like. In the paying of bills, the user will select the bill payment transaction from a list of transactions. The user will be prompted to make one or more manual entries into machine, like the amount of the bill, the amount being paid by the user which should be equal to or less than the check; and the user's account number on the bill. The machine will scan and interpret the user's account number on the bill, the full amount due, and the date field. If the amount being paid is other than the full amount of the bill, a prompt to enter the tendered amount is provided to user on a screen or the like. When the amount of the check or the like from which the funds are derived is greater than the amount being paid, the user may be prompted to have the remainder of the funds paid in cash or loaded into a balance of a debit or a smart card. When paying a bill or making a deposit, the amount field of the document is analyzed on the bill or the deposit slip and compared to the amount manually entered by the machine user. This provides one validation procedure. In some instances, when cashing or depositing a document such as a check, the drawer of the check may have indicated the amount of the check at a MICR line. For example, large employers may issue authorized payroll checks for its enrolled employees. Those payroll checks are issued with a MICR line having the amount of the check thereon. In such instances, the MICR amount line may be read and used to validate the document and the amount to be paid without any comparison of CAR and LAR lines, as is the case for checks that lack a MICR amount thereon. In accordance with an important aspect of the invention, the check, money order or the like is scanned and an image therefrom is dissected with extracted image information being obtained for several recognition fields. The recognition fields are processed to provide a list of amount results ranked by confidence values. The user-entered amount and these confidence values are provided to a processor for transaction arbitration involving cross-validation according to rules. If there is validation of the arbitration using the rules, the transaction is then taken, such as cashing a check, paying a bill, or making a deposit. The usual recognition fields for a check are the LAR and CAR. When a remittance document is also provided to the ATM machine for paying a bill or the like, the remittance document is scanned and its image dissected with one recognition making a deposit field being the amount for the remittance. A list of amount results are ranked by confidence levels and they are provided to the processor for transaction arbitration under the rules. The remittance amount is cross-validated with the check amount results in the transaction arbitration; and, upon validation, the remittance transaction action then proceeds to completion. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of an apparatus embodying the invention including a left section, a central section, and a right section; FIG. 2 is a top plan view of the three sections of the machine shown in FIG. 1; FIGS. 2A and 2B are views of an imaging station for scanning a document; FIG. 3 is a left side view of one section of the apparatus shown in FIG. 1; FIG. 4 is a right side view of the central section of the apparatus of FIG. 1; FIG. 5 is a right side view of the right section shown in FIG. 1; FIG. 6 is a enlarged view of the front of the apparatus of FIG. 1 showing the various insertion slots or receiving slots on the apparatus of FIG. 1 with identifying indicia thereon; FIG. 7 is a rear view of the machine shown in FIG. 1; FIG. 8 is a flow chart for showing the operations occurring after insertion of the card and for verification; FIG. 8A shows the screen with the instruction to PLEASE INSERT YOUR CARD; FIG. 8B shows a screen prompting entry of a user's password; FIG. 8C shows the progression of the password verification operation; FIG. 8D shows the screen when an incorrect password has been entered; FIG. 8E shows that the password is not correct and that the card is being retained; FIG. 8F shows a screen display prompting the user to make a touch screen selection of the language in which the transactions are to be processed; FIG. 9 shows on the screen the money exchange or transactions options available for the user; FIG. 9A is a flow chart which shows the initial welcoming and the various options available to the user; FIG. 10 is a screen prompting a checking or savings step as part of a transaction; FIG. 11 is a screen showing different amounts for withdrawal from checking; FIG. 11A is a flow chart showing the operations for a withdrawal transaction; FIG. 12 is a view showing the screen of having an amount prompt for a withdrawing from saving transaction; FIG. 13 is a flow chart with respect to making a deposit; FIG. 13A is a screen showing the prompt for the source of a deposit into checking; FIG. 13B shows a screen providing for entry of the amount of a check to be deposited; FIG. 13C is a screen showing a prompt to endorse or sign the back of the check; FIG. 13D shows the screen with a message of showing progress in confirming; FIG. 13E shows a screen prompting the user to take a transaction receipt; FIG. 13F is a screen with respect to a transaction for a deposit into saving; FIG. 13G is a screen requesting the amount of cash to be deposited; FIG. 13H is a flow chart showing machine operations with respect to a cash deposit; FIG. 13I is a screen showing the amount of cash deposited; FIG. 13J shows a request to deposit the cash into the cash acceptor slot; FIG. 13K shows a machine verification of completion of the cash deposit; FIG. 14 is a flow chart with respect to the document scanning and verification operations; FIG. 15A is a screen that shows an inquiry to the user requesting a decision as to making a further transaction; FIG. 15B is a screen display of a touch screen version of the screen display shown in FIG. 15A; FIG. 16 is a view of the cashing check screen; FIG. 16A is a flow chart showing the operations with respect to cashing a check; FIG. 16B shows a screen for requesting the manual entry of the amount of the check to be cashed; FIG. 16C requests the signing of the back of the check; FIG. 16D is a screen showing a request to re-insert the inverted check; FIG. 16DD is a screen requesting the user to re-enter the check amount; FIG. 16E shows a bar graph of the progress with respect to the reading of the check; FIG. 16F shows a check cashing and the amount that is available to be received in cash; FIG. 16G shows the completion of the check cashing and the receipt for the amount deposited to the user's account; FIG. 16H is a touch screen display version of the screen shown in FIG. 16B; FIG. 17 is a flow chart showing the operations with respect to cashing a money order; FIG. 17A is a screen shown to the user when cashing a money order; FIG. 17B requests the signing of the back of the money order; FIG. 17C states that the money order cannot be cashed; FIG. 18 shows the screen used when typing in the name of the payee with respect to a money order being purchased; FIG. 18A shows the amount of the money order being purchased; FIG. 18B is a flow chart showing the various operations being performed when buying a money order; FIGS. 18C and 18D show the method of payment and the total transaction at the screen that the money order is being printed and the request to the user to take her receipt; FIG. 19 is a screen display for wiring money; FIG. 19A shows the account to which the money is to be wired and the name of the bank having the account; FIG. 19B shows and requests the entry of the Federal routing code; FIG. 19C shows the account number being added; FIG. 19D shows a screen requesting the amount and shows a service charge; FIG. 19E is a flow chart showing the operations for a wire transfer; FIG. 19F shows the total of the transaction and requests a selection of the method of payment; FIG. 20 is a screen showing a number of bills that can be paid through the apparatus; FIG. 20A shows a telephone bill, service charge and total amount to be charged for payment of the telephone bill; FIG. 20B shows a screen requesting entry of the telephone bill into the scanner slot; FIG. 20C shows the selection of a gas bill for payment as well as a telephone bill; FIG. 20D requests insertion of the gas bill into the scanner slot; FIG. 20E shows the payment for a credit card bill; FIG. 20F shows the amount of payment with respect to the telephone, gas and credit card bills; and the request for the method of payment; FIG. 20G shows the screen when the bill is to paid by credit card; FIG. 20H is a flow chart showing the operations that occur during a bill payment; FIG. 20I shows a screen confirming payment of the bills; FIG. 20J is a touch screen display version of the screen shown in FIG. 20; FIG. 21 shows a screen for purchase of items such as stamps, smart cards or telephone cards; FIG. 21A is a flow chart showing the various operations that occur during the purchasing transaction; FIG. 21B shows a screen displaying request for a purchase of three smart cards and one telephone card; FIG. 21C shows the total transaction and requests a selection of the method of payment; FIG. 21D shows a screen showing a $25.00 transaction and showing how much has been inserted to pay for the transaction; FIG. 21E shows that $20.00 has been paid; FIG. 21F shows that $21.00 has been paid; FIG. 21G shows that $24.00 has been paid; FIG. 21H shows that the total of $25.00 has been paid and shows a message on the screen to take the merchandise; FIG. 21I is a touch screen display version of the screen shown in FIG. 21; FIG. 22 is a flow chart showing the various operations with respect to cash payment; FIG. 23 shows the payment of change either by credit to a card or by a deposit into a bank account; FIG. 24 is a block diagram of the apparatus shown in FIG. 1; FIG. 25 is a flow chart of a signature verification and character recognition process; FIG. 26 is a flow diagram showing details of the overall operation of the processor for generalized document handling; FIG. 27 is a flow diagram showing generalized flows for various types of document processing involving checks; FIG. 28 is a generalized flow diagram showing steps related to processor operation related to remittance processing or bill payment; FIG. 29 is a generalized flow diagram for depositing a check; FIG. 30 is a generalized flow diagram for the processor when cashing a payroll check; FIG. 31 is a generalized flow diagram for character amount recognition (CAR) and legal amount recognition (LAR) for an instrument being processed; and FIG. 32 provides details of processor operation for image character recognition of the type including CAR and LAR; FIG. 33 is a flow diagram for generating a bounding box; FIG. 34 is a flow diagram for zooming an image in the bounding box; FIG. 35 is a flow diagram for the bounding box; and FIG. 36 is a generalized flow diagram for check validation using rules. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustration, the invention is embodied in an automated banking system that includes an apparatus 10 having a housing 12 for housing the components of the apparatus 10 which are to receive an ATM card which can be inserted through an insert, slot or opening 14 in a front wall 16 of the housing 12. The insert slot 14 will accept the usual ATM card, credit cards, IC cards or smart cards. The card slot 14 is located immediately above an alphanumeric user keyboard 18 and below a user display 20 comprising a touch screen of the type sold by Dyna-Pro under its Model No. DTFP 95633. The user keyboard 18 supplies command signals to a microcomputer 21, in this embodiment a 133 MHz Pentium-based personal computer having a 2.1 gigabyte hard disk drive for storing software, a 32 megabyte random access memory for storing instructions and operands, a 133 MHz Pentium microprocessor, an ISA bus, a PCI bus, a serial interface, and a parallel interface. (FIG. 3). The microcomputer 21 executes application software under Windows 95, which among other things, responds to keystrokes on the user keyboard 18, and signals from other input devices as set forth below. The microcomputer 21 drives the output display 20 in response to the software it is executing and the various signals it receives from the input devices connected to transfer signals to it. Located immediately behind the insert card slot 14 is a magnetic card reader 22 (FIG. 4) which will read the ATM card, send signals to the microcomputer 21 through a serial communication card 21a, and immediately cause initialization, via the microcomputer 21, of all hardware and software parameters for an operation. The touch screen 20 is provided to assist the user in identifying for the machine the area of the image occupied by the account number and dollar amount of a bill, as will be explained. The illustrated keyboard 18 is a very tough, vandal-resistant, alphanumeric industrial keyboard, such as the Model 300 manufactured by Everswitch USA of Silver Springs, Md. The preferred display 20 is a flat LCD display panel sold by Sony Corporation. The keyboard and display panels are selected because they are considered to be tough, strong, easy-to-use, and difficult for thieves or criminals to vandalize or to misuse to illicitly obtain funds from the machine. A backup storage device 23 connected to the computer 21 provides further security for the software and data stored on the hard drive. As shown in connection with the flow chart of FIG. 8 entitled “insert card and verify screen”, the user will see on the screen display 20 the welcome message and a prompt to insert the banking (or ATM) card and to verify a user password with the banking network. The user will be prompted to select English or Spanish as the language for the transactions as shown in FIG. 8F. The user will then touch the screen display to select English or Spanish for the transaction language. In a card insert routine 300 a test is made in a step 302 to determine whether the magnetic-striped identification card has been placed in the card reader 22. If it has not, control is transferred to a step 304 prompting the user to insert the card through the card slot 14. The card is then read in a step 306 and the user is prompted and enters a password in a step 308. A test is made in a step 310 to determine whether the password is verifiable by the banking network when communicated over a modem 29. If the password is not, a test is made in a step 312 allowing the password to be entered three more times. Assuming three unsuccessful tries in a step 314, an incorrect password message is displayed and process loops back to the step 308. If the password is found to be correct after step 310 the transaction is proceeded with in a step 316. If as a result of step 308 the transaction is cancelled, control is transferred to a step 320 testing for whether another transaction has been requested. This may be done by screen prompts to be answered by the user as exemplified by the screen displays shown in FIGS. 15A and 15B. The selection may be made by keypads 26 and 27, as shown in FIG. 15A or by touch screen contact with the appropriately labelled portion of the screen display shown in FIG. 15B. If it is, a service option screen 322 is displayed. If it is not, a test is made in a step 324 to determine whether the card is in the card reader 22. If the card reader 22 does not have a card in it the welcome screen is displayed in a step 326. If the card is in the card reader 22 it is ejected back to the customer in a step 328. In the event that the password is entered more than three times control is transferred to a step 330 causing the card to be eaten or retained and placed in a card bin. In a step 332 the message is displayed on the touch screen that the card has been retained and the touch screen after that displays the welcome screen in the step 326. The display shown in FIG. 8A prompts the user to insert the card. After the insertion of the card, the display will prompt the user to please enter the PIN or password number, as shown in FIG. 8B. The processing of the entered password is shown in FIG. 8C. If an incorrect password has been used with the card, then the screen display will display, as shown in FIG. 8D, the phrase “incorrect password”, and prompt the user to “please try again”. If the subsequent or second password is incorrect, the machine retains the card and the screen display will show on its face, as shown in FIG. 8E, the statement that there still is an incorrect password, and that the card is being retained. The card has been “eaten” by the machine. The card can be retrieved only by contacting the financial institution owning the machine. Having verified the card and having verified the password or PIN number with the banking network over the modem 29 or the like, the machine 10 is ready to proceed with a transaction. The modem 29 communicates with the computer 21 through the serial interface 21a to which it is connected. The user display screen 20 will then display the transaction options available to the user, such as those shown in FIG. 9 which include 1) withdraw; 2) deposit; 3) cash check; 4) cash money order; 5) buy money order; 6) wire transfer; 7) bill payments; 8) purchase (lottery tickets, stamps and telephone cards). The display shown in FIG. 9 will be on the panel display 20 and adjacent the pair of flanking additional keypads 26 and 27 (FIGS. 1 and 6), which have arrow keys which are aligned with these options 1-8. That is, the pressing of the arrow key 26a opposite the number “1)” “WITHDRAW” on the screen 20 will initiate a withdrawal. Whereas, the operation of the second arrow key 27a (27b ?) in the right hand bank of keys will initiate a “BUY MONEY ORDER” operation, to be described hereinafter. Assuming the user has selected the “1)” withdrawal option by depressing the arrow key 26a opposite number “1) WITHDRAW”, the screen display 20 will then display a request to an account for a withdrawal, i.e., from a checking or savings account. This is shown in FIG. 10 with the display of a “1) CHECKING” and a “2) SAVINGS” on the screen display opposite the arrow keys 26a and 26b. Assuming that the user wishes to withdraw money from a checking account, the user will press the arrow key 26a. The screen display 20 will then show the display of FIG. 11 with the display labeled “WITHDRAW FROM CHECKING” and with the monetary amounts “20”, “40”, “50”, “100”, “200” and other listed opposite the selection arrow keys 26a-26c and 27a-27c, respectively. By operating one of the particular arrow keys 26 and 27, i.e., the arrow key $20.00 for withdrawal from checking, will signal other positions of the apparatus 10 to perform a number of operations shown on the flow chart entitled “WITHDRAW screen” shown in FIG. 11A. In a step 340 the withdraw screen is engaged and in a step 342 the user is prompted by the screen to insert the card and a verify screen is displayed. If the card is verified control is transferred to a step 344 allowing the user to choose from a present withdrawal amount. If the user chooses to cancel the transaction control is transferred to a step 346 testing for another transaction. If the user chooses not to choose from a preset withdrawal amount, the user may enter the withdrawal amount in $5.00 increments in a step 348 or may cancel the transaction and proceed to the other transaction test step 346. Assuming that the withdrawal amount has been entered in $5.00 increments, the withdrawal transaction is performed in a step 350 by checking over the banking network. In a step 352 a cash dispenser 30 dispenses the withdrawn amount and in a step 354 the receipt is printed by the receipt printed. Control is then transferred to the step 346 testing for additional transaction prompts. If there is, the service option screen is then displayed in a step 360. If not, the card is ejected from the card reader 22 in a step 362 and the welcome screen is displayed in a step 364. A connection will then be made by the electronics network and modem 29 via the banking network to access the customer's account in the bank; and then there will be an operation of the cash dispenser 30 (FIGS. 1 and 5) to dispense $20.00 in cash. The cash dispenser communicates with the computer 21 through the serial communication device 21a to which it is connected, as shown in FIG. 24. The cash dispenser 30 herein is a typical cash dispenser unit used in an ATM machine. The illustrated cash dispenser is a G & D America, Inc. Model ACD which is made by Giestcke and Debrient America, Inc. The illustrated cash dispenser 30 has four (4) bins. Each bin can hold four hundred notes. The preferred cash dispenser 30 is loaded with four hundred $5.00 notes in one bin. The other three bins are each loaded with four hundred $20.00 notes. Manifestly, more or less bins may be used and also different cash dispensers may be used than that described herein. The illustrated and preferred cash dispenser 30, as shown in FIG. 5, is mounted for sliding horizontally to the right for reloading, and is slid back into the position shown in FIG. 5 where it is supported on slide tracks 32 mounted on the housing 12. The cash being dispensed drops through a chute 36 into a hopper 38 having a pivoted axis door 40. The pivoted access door 40 allows the dispensed cash to drop into a dispensed cash bin 42. As shown in FIG. 6, in order to withdraw dispensed cash the user will reach through a cash bin window 46 in the front housing wall 16 and remove the cash from the bin 42. As shown in FIG. 7A, access to the interior of the housing 12 and to the cash dispenser 30 for the replenishing the cash is through a rear housing door 44. The rear housing door 44 has a double security lock 47a and 47b and a handle 48. With the rear housing door 44 open, the cash bins can be accessed and slid along the tracks 32. The double security lock 47a and 47b provides security for the cash sections in the normal manner of an ATM. If the user had chosen the “SAVINGS ACCOUNT” on the display 20 for withdrawal transaction (shown in FIG. 10), she would have pressed the arrow key 26b opposite the “SAVINGS ACCOUNT” prompt on the screen display 20. As shown in FIG. 10, the display 20 would then show the withdrawal from savings screen having the prompt “WITHDRAW FROM SAVINGS.” The user is requested to enter the amount in $5.00 increments of the amount to be withdrawn. In this instance, the user operates the keyboard 18 to type in $500.00, the amount to be withdrawn from savings. In such event, the withdraw screen under the control of the microcomputer 21 executing the steps of the flow chart shown in FIG. 12 used to perform the withdrawal from savings by the modem through the banking network, and the cash dispenser 30 is then operated to dispense the cash into the cash bin 42 for removal by the user. For either a withdrawal from savings or a withdrawal from checking, it is preferred to print out a receipt with a receipt printer 50 shown in FIGS. 1 and 3. The receipt printer 50 is connected to the computer 21 through a parallel communication device 51. The receipt printer 50 dispenses a printed paper receipt which is fed therefrom and is issued, in this instance, from a receipt dispensing slot 52 in the front wall 16 of the housing 12. The user will then receive the receipt which shows not only the amount being withdrawn but also the transaction fee. Thus, the total withdrawn from checking or savings for the transaction will include not only the cash dispensed but also the transaction fee, i.e., $1.00 per transaction. The illustrated receipt printer 50 is preferably a Model MP342F, manufactured by Star Micronics America, Inc. of Piscataway, N.J. The receipt printer 50 has an automatic cutter for cutting the receipt after printing. Manifestly, other printers or receipt generators may be used than the model described herein. The welcome screen is displayed in a step 220, as shown in FIG. 9A. In a step 222 all hardware and software parameters are initialized. In a step 224 the service options screen is displayed, allowing a choice to enter. The withdrawal screen 226, the deposit screen 228, the check cashing screen 230, the cashing of money order screen 232, buy money order screen 234, the wire transfer screen 236, the bill payment screen 238 or a make purchase screen 240. Assuming now that the user had selected the deposit #2 option as shown in FIG. 9, and wanted to deposit into the checking or savings account, the user would have pressed the arrow key 26b of the keypad 26, which is opposite “DEPOSIT.” This action results in a request whether to deposit into a checking account or into a savings account. Assuming the deposit is to be made into the checking account, the flow chart of FIG. 13 shows the steps performed by apparatus 10 which will be described in greater detail hereinafter. The deposit screen, which is displayed in a step 380, requests insertion of the card and displays a verify screen in a step 382. If the card is not inserted control is transferred to a step 384 testing for whether any other transaction is to be carried out. If it is, in a step 386 the service option screen is displayed. If not, in a step 388 the card is ejected and the welcome screen is displayed in a step 390. In the event that the card has been verified a prompt is made to the user in the step 392 as to the type of deposit. If the user elects to cancel the transaction, control is transferred to the step 384. If the user selects “Cash”, a cash deposit screen is displayed in a step 394. If they select “Checking”, a check deposit screen is displayed in a step 396 and if they choose “Money Order,” a money order deposit screen is displayed in a step 398. Control is then transferred to a step 400, causing the selected transaction to be performed by the modem 29 through the banking network. In a step 402 the receipt is printed out and control is then transferred to the other transaction test step 384. The deposit into checking screen display (FIG. 13A) prompts the user with the statement: “WHAT WOULD YOU LIKE TO DEPOSIT IN YOUR CHECKING ACCOUNT 1) cash; 2) check; or 3) money order”. Assuming that the user has elected to deposit a check, the check transaction will be selected by pressing the arrow key 26b of the keypad 26. As shown in FIG. 13B, a request then will appear on the screen display 20 labeled “DEPOSIT CHECK” opposite a window 52 for the amount of the check. In the window 52, the operator will then use the keyboard 18 to enter the deposit amount of $675.52. In this instance, a service charge in the amount of $1.00 will also be displayed, as shown in FIG. 13B to the user. If the user has not endorsed the check, the user will see, upon entering the amount, will be that shown in FIG. 13C, which will request the user to “sign the back of the check”, and “when ready to insert the check into a scanner slot”. A scanner slot 54 is located above the user display 20, as shown in FIGS. 1 and 6. In this instance, the check will be inserted vertically. The illustrated scanner slot 54 is approximately 4″×9″, and the inserted check will be scanned while it is in this vertical position, as will be described hereinafter. As the check enters the scanner slot 54, it is gripped by feed rollers and moved along a feeding track 56 (FIG. 2). The check feeds directly into and stops at an imaging station 55 where the check is scanned or images of the front and the back sides of the check are captured. A scanning and confirm flow chart is shown at FIG. 14. It will be described in greater detail hereinafter with respect to the software control and operations of the machine. As shown in this flow chart, an optical character recognition (OCR) scanner scans the document. A magnetic ink (MICR) reader reads the magnetic ink data on the check, which will include the bank's identification number as well as the user's checking account number with the bank. Also, while the check is in this stopped position, its legal line (LAR) will be scanned, and the CAR line will be scanned to verify that the check is for the correct amount, in this instance $675.52. Also, while in the vertical stopped position, it is preferred to have a camera unit 58 and 60 (FIG. 2) disposed on opposite sides to capture images of both sides of the check and connected through a SCSI device 59 to the computer 21. The images are stored on a magnetic recording medium in TIFF format and are provided with a tag so that the image file, as shown in FIG. 14, can be later accessed if so desired. At the beginning of the scanning operation, the check image is processed to ascertain if the check has been inserted correctly. In the scanning operation 420 the document is inserted in the scanner slot in a step 422. The scanner using the camera 58 and 60 scans both sides of the documents and reads the magnetic ink via a magnetic transducer in a step 424. The document is placed in the holding area in a step 426 and a determination is made in a step 428 as to whether the document is a check or money order on the basis of the presence or absence of the magnetic ink data. A check is also made in a step 430 to determine whether the document is inserted correctly. If it is not, the document is ejected from the document slot 54 in a step 432 and the touch screen 20 displays if the document is inserted incorrectly in a step 434 following which control is transferred back to the step 422. If the document is not a check or money order as determined in a step 428, control is transferred to a step 440 causing both sides of the document to be saved in a tagged image file format. If the document was inserted correctly as tested for in step 430, both sides of the document are saved in a step 440. In a step 442, the images are analyzed by amount recognition software of the types supplied by Mitek of San Diego, Calif., in particular its Quickstrokes Version 2.5 software. Control is transferred to that software from step 442 and as may best be seen in FIG. 25, in a step 450 the software is run. In a step 452, the software recognition device is created and initialized. The form files are read in a step 454, which form files include the positions where the courtesy amount recognition (CAR) and where the signature is likely stored in the fields within the document. In a step 456 the scanned image file is read and in a step 458 the neural network contained within the Quickstrokes software recognizes the characters written in the signature line as well as the characters written in the courtesy amount recognition (CAR) space and in the amount recognition (LAR) line. The recognized characters are then evaluated from the standpoint of a confidence level in a step 460, and character strings representative of those characters are returned to the software set forth in FIG. 14 for further evaluation. Referring now to FIG. 14 in a step 470, the strings representing the signature verification as well as the amount on the document are forwarded to the bank network by the modem 29 for confirmation for payout. If there is no confirmation control is transferred to a step. 472 causing the document to be ejected from the document slot and in a step 424 a document rejection message is displayed. In a step 476 the current transaction is denied. In the event that the documents are confirmed in a step 470, the check or money order is stacked in an accepted documents bin in a step 478 and confirmation of the current transaction is sent to the banking network in a step 480. If the images are not stored, the check is carried around the U-shaped feed path 61 back to an eject slot 61a in the housing wall 14 for retrieval by the user. The eject slot 61a is parallel with and to the left of the insert slot 54. Assuming that the check has been re-inserted correctly and images of both the front and back have been captured, then the check is sent to an escrow or holding area 64 in the check feed track. The holding area 64 communicates through the serial communication device 21a with the computer 21, as shown in FIG. 24. As best seen in FIG. 4 at the escrow area 64, the check is held for either depositing into a store bin 66 if the check has been qualified and accepted, or the check depositing transaction, the check will be fed from the escrow area back to the eject slot 61a for removal by the user if failure to verify the signature causes the check to be rejected for deposit. Assuming that the banking network has been connected by the modem 29 to other portions of the apparatus 10 and that the check has been verified, the amount deposited is sent over the banking network to the identified bank and identified account of the user for deposit. The receipt printer 50 is then operated to provide a written receipt to the user showing the amount deposited minus the transaction charge of $1.00. Referring now to FIGS. 2A and 2B, the document handling of a money order or a check will now be described in greater detail. The check is inserted vertically through the scanner slot 54 and passes in front of a pair of first infrared sensors 101 and 102, which sense that the check has been inserted. These sensors are on opposite sides of a guide or feed track 100 which includes a pair of spaced parallel plates 103 and 103a extending inwardly to the imaging station 55. Immediately beyond the infrared sensors 101 and 102, which detect the insertion of the document, is a pressure roller 105 to push the check against the plate 103. The check is pushed forwardly past a set of infrared sensors 110 and 112, which will detect when the check is fully inserted into the scanner slot and is gripped by a feeding belt 112 that runs through an entry slot 114 between the image scanners 58 and 60 at the imaging station 54. The feeding belt 112 extends through imaging station to a large diameter roller 121 (FIG. 2B). The check pauses in its travel at the imaging station 54, where the image taking video or other scanners 58 and 60 take images of the front and back of the check. Optical character recognition readers read the magnetic ink recognition characters for the bank and for the customer's account. Electronic signals from the image takers 58 and 60 provide information concerning the signature for the check, the legal line and the amount written thereon, and the CAR line and the amount written thereon, all of which are stored magnetically, in this instance, and provided with tag number for later recapture. As best seen in FIG. 2B, a U-shaped track 120 is provided around the large diameter roller 121 to guide the check to reverse its direction of travel and to move it into a slot between plates 122 and 123 of the check guide track 100 to a pair of inlet infrared sensors 125 and 126, which sense the check coming into the inlet of the escrow area 64. The feeding belt 112 is a cogged timing belt which carries the checks about the drum 121 and between the plates 122 and 123 to the inlet to the escrow area. The cogged feeding belt is driven by a stepper motor and travels about guide rollers 127. At the escrow or holding area 64, there is provided a large belt driving drum 130 which drives a cogged feeding belt 131 for conveying the check first upwardly and to the left into the holding area and from the latter into the deposit bin 66 above the holding area 64. If the check is to be rejected, the feeding belt 131 reverses its direction of travel to eject the check through the eject slot 62. The driving roller 130 includes a stepper motor 132, which is mounted on the top of the roller 130. The stepper motor 132 is reversible in its rotation for rotating a drum 130 and the feeding belt 131 in opposite directions and through a controlled distance. Infrared sensors 125 and 126 sense the passage of the check from the imaging station 55 into the escrow area 64. The feeding belt 131 is guided along and travels past a series of guide rollers 134a, 134b, 134c and 134d to the top of the holding area. The endless timing belt 131 turns about the top guide roller 134d and travels downwardly and to the right past a roller 136 to return to a side of the drum 130, as seen in FIG. 2A. The check is pushed against the timing belt 131 to travel with the timing belt by four sets of pressure rollers 140a, 140b, 140c and 140d. At the top of the holding area is another pair of infrared sensors 141 and 142, which sense the arrival of the upper edge of the check and they signal that the check has been moved completely into the holding area with the lower end of the check being at or above the rollers 140a and 134a at the bottom of the holding area and aligned with the eject slot 62. Once the check has been accepted, the stepper motor 132 is turned to drive the drum 130 and the feeding belt 131 to cause the check to travel upwardly into the overhead deposit bin 66. On the other hand if the check is rejected as being unacceptable, the feeding belt 131 travels in the opposite downward direction to push the lower edge of the check through the eject slot 62 and return it to the user. A lower end of the guide plate and a spring guide finger 147 guide the outgoing ejected check to slide and travel along a short guide plate 148 to the aligned eject slot 62. Infrared sensors 150 and 151 (FIG. 2A) at the bottom of the holding track sense when the check has been removed from the eject slot by the machine user. During the deposit transaction, the screen display 20 will show a confirming message, such as shown in FIG. 13D, in the form of a bar that progresses from left to right in window 69 being viewed by the user. As the receipt is generated by receipt printer 50, the screen display 20 (FIG. 13E) will show that $674.52 “WILL BE DEPOSITED INTO YOUR ACCOUNT. PLEASE TAKE THE RECEIPT WITH YOU.” If, rather than depositing the check into a checking account, the user had selected the option to deposit into a savings account, the screen would display the deposit into savings account shown in FIG. 13F. Then, the user would press the arrow key 26b for the “CHECK”; and the check would have been deposited in the same manner as described above with respect to a deposit into a checking account. A cash receipt would have been provided to the user, as was the cash receipt generated for the deposit into the checking account. Assuming that the user had decided to deposit cash into checking and had pushed the #1 cash button 26a of the keypad for the display screen of FIG. 13A or had pressed the same button for a cash deposit into savings (FIG. 13F), the processor would follow the steps of the cash deposit flow chart shown in FIG. 13H. In the cash deposit process 500 as set forth in FIG. 13H a cash acceptor 62 is initialized in a step 502. Currency is inserted in the cash acceptor 62 in a step 504 and is accepted thereby. The bills are read and are transferred to a deposited cash bin in a step 506 and the total of the bills presented added up in a step 508. If the user elects to deposit more bills in the cash deposit in a step 510 control is transferred back to step 504. If not, control is transferred to a step 512 where the deposit transaction is proceeded with. The user display 20 as shown in FIG. 13G for deposit cash would display the prompt “PLEASE INSERT YOUR BILLS INTO THE ACCEPTOR SLOT 60, WHICH IS SHOWN IN THE RIGHTHAND SECTION ABOVE THE CASH DISPENSER.” As may best be seen in FIG. 5, the cash dispenser accepting slot 60 leads into a cash acceptor module 62, which accepts cash, specifically bills in denominations of $1.00, $5.00, $10.00 or $20.00. As shown in FIG. 24, the cash acceptor module 62 is electronically connected to the computer 21 via a resistor network 62a having a plurality of current limiting resistors. The resistor network 62a is connected to a digital I/O board 62b, in this embodiment a National Instruments PC-DIO-96. The digital I/O board 62b is coupled to the computer 21. The cash acceptor module 62 counts the deposited bills and has a bin in a hopper 64 to receive the counted bills. The cash acceptor module 62 is pivotally mounted at 66 to be swung to a dotted line position for emptying deposited bills therefrom. The preferred cash acceptor module 62 merely stacks the inserted bills and counts the same. The cash acceptor module 62 is preferably a Mars Electronics? International Cash Acceptor Model AL4-L1-U1M, which is one of several available cash acceptors. It will not only stack the bills and retain them in the machine 10, but will add up the total amount of cash. The cash flow chart shown in FIG. 13H will be described in greater detail hereinafter in connection with the software and overall control of the machine. The deposit transaction proceeds from the flow chart of FIG. 13H back to the flow chart of FIG. 13 to proceed through the modem and banking methods to make the deposit into the user's checking or savings account. The machine 10 will operate the receipt printer 50 to print a receipt to be dispensed to the user through the receipt slot 52, showing the amount deposited less the transaction fee, which is illustrated as $1.00 in this instance. When depositing cash, the illustrated cash acceptor 62 will total the cash received and show this cash being deposited, as shown on the screen 20 which shows that the $20.00 has been deposited after $45.00 more dollars have been deposited, making for a total deposit of $65.00, as shown in FIG. 13J. A receipt will then be printed by the receipt printer 50, and the user will be notified that $65.00 will be deposited in the user's account (FIG. 13K). Assuming that the user, when prompted by the options screen of FIGS. 3 and 9, has elected to press the arrow key 26c to initiate the check cashing transaction, the user display 20 will prompt the user to enter the amount of the check into the window 68 (FIG. 16). The flow chart, with respect to cashing a check, is shown in FIG. 16A. The cash check process is entered at a point 520 and as a result, the magnetic card reader 22 accepts the magnetic identification card in a step 522 and displays a verify screen. The user can exit the transaction by transferring to a step 524 where he or she is prompted for another transaction. If not, the amount of the check is entered in a step 526 and the check is scanned and confirmed in a step 528 as set forth previously. The user then enters an amount in a step 530 to be received in cash and the banking network is accessed in a step 532 to determine whether their is a balance from which the check may be cashed. If so, in a step 534 the cash dispenser dispenses cash in the cash amount and in a step 536 the receipt is printed by the receipt printer. Control is then transferred to a step 524 and if another transaction is desired, the service option screen is accessed in a step 526. If another transaction is not wanted, control is transferred to a step 528 causing the card to be ejected from the card reader and in a step 530 the welcome screen is displayed. The user enters through the keyboard 18 the amount, such as $90.00, shown in FIG. 16B, the amount will be scanned and confirmed, and the service charge of $1.00 is shown on the screen display of FIG. 16. The user may select to continue the transaction or to cancel it by pressing the appropriate button of keypads 26 or 27. The touch screen display shown in FIG. 16H allows the user to make the selection by touching the portions of the display labelled either CONTINUE or CANCEL. If the user has not signed the back of the check, the user will be requested to do so (FIG. 16C). If the check was inserted backwards, as it is viewed by the scanner, the check will be returned through the rejected material outlet slot 62. The user will invert the check and insert it now in the correct vertical position into the insert slot 54. From there the check will be carried into the scanning imaging station where cameras 58 and 60 will capture the images of opposite sides of the check. The processor 21 by executing document verification software will then analyze the signature image and compare it with the profile signature of the user. Likewise, the processor, by using the verification software, will also read the cursive legal amount (LAR) line and the written numerical amount at the CAR line, as will be described hereinafter in connection with the document verification software in greater detail. After re-insertion of the check, the user will be requested to re-enter the amount of $90.00 (FIG. 16D). The check image will again be processed and if the amounts match the keyed-in amount the user display will show an “OK” for the amount (FIG. 16D). During the scanning and the verification operations with communication to the user's account, through the banking modem, the screen will display “OCR” with a movable bar, as shown in FIG. 16E. The next prompt shown on this screen will be to enter the portion of the check amount that the user wants to receive in cash. The cash is selected in $5.00 increments. The machine then informs the user that any remaining amount of the check will be received in cash (FIG. 16F). With reference to the specific example given herein as shown in FIG. 16F, the user's screen display 20 will show that there has been a $90.00 check scan with a service charge of $1.00, leaving a balance of $89.00. The operator will have used the keyboard 18 to enter the request for $40.00 cash, in $5.00 increments, as shown in window 70. As will be explained in greater detail in connection with check cashing flow chart of FIG. 16A, the cash dispenser 30 will then be operated to dispense $40.00 into the cash bin 56, which the user will then remove. As shown in FIG. 16G, the amount of $40.00 will be deposited in the user's account through the banking network; and the receipt printer 50 will print a receipt for the deposit of $40.00. The cashing of the money order is much like cashing a check. It will be described hereinafter in connection with the flow chart shown in FIG. 17, and in connection with the screen of FIG. 17A. The cash money order process is accessed in a step 570. The magnetic card is prompted to be inserted in a step 522 and a verify screen is raised. If the user decides to exit the transaction, she may so signal and control is transferred to a step 574, testing for whether another transaction is desired. Assuming that the card is verified and that the transaction is to proceed, the amount of the money order to be paid out is entered in a step 576. In a step 578 the money order is inserted and scanned and confirmed, and in a step 580, assuming the confirmation occurs, the user enters the amount for the money order to receive in cash. In a step 580 a query is generated by the modem 29 to the banking network to determine whether the amount of the money order is backed by funds. Assuming that it is, in a step 584 the cash dispenser dispenses the cash amount and a receipt is printed in a step 586. Control is then transferred to the other transaction test step. If another transaction is desired the service option screen is displayed in a step 588. if not, the card reader is ejected in a step 590 and the welcome screen is displayed in a step 592. Assuming that the user, when viewing the options available (FIG. 9), had pressed the arrow 26d opposite “cash money order” to institute this transaction, the user is then prompted, as shown in FIG. 17A, to operate the keyboard 18 to enter the amount of the money order, which, in this instance, is $750.00. The screen will also show the transaction service charge of $1.00 and the available amount of $100.00 in cash. The cash money order screen displays $100.00 in a window 71 and prompts the operator to enter from the keyboard 18 the amount of cash that the user would like to receive in $5.00 increments. In this instance, the user has entered $100.00 into the window 71. In a manner similar to that used for the scanning of the check, the cameras 58 and 60 photograph both sides of the cash money order and locate the indicia showing the amount of the money order and read the amount indicia. The magnetic ink indicia identifying the issuer and the account of the issuer are read; and the signature on the back of the money order is scanned and confirmed. Then a communications network via a modem is connected to the issuer's account, indicating that the authenticity of the money order is being checked. When the machine 10 receives signals that the money order is authentic, the cash dispenser 30 is then operated to transfer $100.00 cash into the cash bin 46 (56?) for removal by the user. If the user had not signed the back of the money order, he would have been informed to reinsert the money order, as shown in FIG. 17B. If the money order could not be processed, it would be returned through the reject slot 62. The user display 20 would state that the money order could not be processed and that the user should check with her financial institution, as shown in FIG. 17C. Assuming the user had selected, in FIG. 9, the #5 option of buying a money order by pressing the right hand button 27a on the keypad, then the buy money order screens and flow chart would have been operative, as will now be described. The first prompt shown on the purchase money order display 20 (FIG. 18), requests the name of the person to whom the money order is to be paid. In this instance, the name is John Doe, as shown in FIGS. 18 and 18A. Having operated the user keyboard 18 to enter the payee's name, i.e., “John Doe,” the user will next enter the amount of $500.00, as shown in window 72 in FIG. 18A. The service charge of $0.50 is shown so that the total amount needed for the purchase of the money is $500.50. As may best be seen in FIG. 18B, it is preferred to provide the purchaser of the money order with a number of options for payment including by cash, by credit card withdrawal from an account of the user, and by a smart card. Or the user may return to the money order, if he so desires. The flow chart for buying a money order is shown in FIG. 18B. In a buy money order transaction, the process is entered via step 600 and the money order recipient's name is entered in a step 602 or if cancellation is desired, control is transferred to another transaction test step 604. Assuming that the recipient's name has been entered, the amount of the money order is entered in a step 606 and in a step 608 a method of payment is chosen causing prompts to occur via a cash payment screen 610, a credit card screen 612, a smart card payment screen 614 or a balance withdrawal screen 616. The particular transaction for payment is then processed in a step 618 and the money order is printed out in a step 620. A receipt is printed in a step 622 and the transaction test 604 is then made. If further transactions are to occur, the service option screen is displayed in a step 624. If not, a test is done in a step 626 to determine if the card is in the card reader. If it is, the card is ejected in a step 628 and the welcome screen is displayed in a step 630. The buy money order transaction will be tagged and, through the banking network, a money order printer 76 (FIG. 1) will print the money order. The money order printer 76 is disposed, in this instance, side-by-side with the receipt printer 50, as is shown in FIGS. 1 and 3 and is connected to the computer 21 through the parallel communication device 51, as shown in FIG. 24. The printed money order is dispensed from a money order dispensing slot 78, which is adjacent to the receipt printing slot 72 in the front housing wall 16 of the apparatus 10. The illustrated money order printer may be similar to the receipt printer 50 and is available from Star Micronics America, Inc., Model MP3342F. It includes an automatic cutter. As shown in FIG. 18C, the user screen display 20 will then display that $500.50 has been withdrawn from the user's account, and that the money order is being printed. Both a money order and a receipt will be issued from the money order slot 78 and the receipt slot 52, respectively. If the user had selected the wire transfer option in FIG. 9 and had depressed the arrow key 27a for wire transfer, the screen of FIG. 19 would be displayed on the user's display 20 prompting the user to use the keyboard 18 to enter the name of the person to whom the money is to be wired. Then the screen display 20 would request the name of the bank, as shown in FIG. 19A, which will be entered, such as First American. The next request of the user is shown in FIG. 19B and that is for the Federal routing code or the routing for the bank for the transfer. The routing is to be typed in by the user using the keyboard. The number “7896654” has been typed in as the federal routing code in FIG. 19B. The account number of the receiver is then requested, as shown in FIG. 19C. The account number in this instance is shown as “987-87654” and has been typed in by the user using the keyboard 18. Having entered the information for the wire transfer to a specific account, the screen display 20 requests the amount to be sent, which in this instance, as shown in window 78 is $850.00. A service charge of 10%, or $85.00 of the $850.00 amount charged is shown to the user bringing the transaction total to $935.00, as shown in window 78a. The flow chart for a wire transfer of money is shown in FIG. 19E. The wire transfer process 640 is started with a step 642 for entering information related to the transfer related to the bank the transfer is to be made to as well as the account. In a step 644 the amount to be transferred is entered. In a step 646 the method of paying for the wire transfer is selected, causing control to transfer to a cash payment screen 648, to a credit card screen 650, to a smart card payment screen 652 or to a withdrawal screen 654. Following that, in a step 656 the selected payment transfer occurs and the wire transfer occurs via the modem 29 over the banking network. In a step 658 a receipt is printed and in a step 660 a test is made for whether another transaction is to occur. If it is, a service option screen is displayed in a step 662. If it is not, a test is made in a step 664 to determine if the card is in the reader. If so, the card is ejected in a step 666 and the welcome screen is displayed in a step 668. A request for the method of payment which can be any of four different payment methods, is shown in FIG. 19F. In this instance, the options of cash, credit card, withdrawal from my account, or smart card may be selected by operating the appropriate keypads 26 and 27 positioned alongside the display 20, shown in FIG. 19F. After selecting the appropriate method of payment, the machine is then connected over the banking network (FIG. 19E) to the bank to deposit $850.00 in John Doe's account no. 987-87654. The receipt printer 50 will cause a printout of the receipt showing a payment and wire transfer to John Doe of $850.00 and a total transaction fee of $935.00, the latter may be charged by credit card, smart card, or withdrawal from my account, as shown in FIG. 19E. On the other hand, the user could have deposited cash of $935.00 in the cash acceptor slot 60. The machine 10 would then count the cash and hold it in the cash acceptor 34. Having finished the transaction, the credit card (if used for payment) would be ejected, as shown in FIG. 19E. Returning again to the options available as shown in FIG. 9, if the operator had pressed the key 27c on the keypad 27 to select the “bill payments” option, then a bill option screen (FIG. 20) would have been shown on the user display 20. The bills which may be paid are listed on the display 20, viz., telephone, electric, gas, cable, water and credit cards. The operator will use one of the keypad buttons on keypads 26 and 27 to select from the screen of FIG. 4 the particular bill to be paid. In the alternative the bill payment selection may be made by touching the appropriately labelled region of the menu display on the touch screen display shown in FIG. 20J. It will be requested on the user display, as shown in FIG. 20A, to enter the amount for the bill selected, such as $129.67 for the telephone bill. Then, the telephone bill may be inserted into the scanning material insert slot 54 where the images of both sides of the bill will be captured. The particular bill payments have to be qualified with the user's account beforehand, and the particular bill has to be recognized so that the amount of the bill and the field specifying money owed can be located as well as the identity of the creditor company—the telephone company, in this instance. The verifier will read the customer's account number, the payee's account number, and the amount of the bill. The position of this data on the bill as well as the script, font, etc. will vary greatly. To aid in reading the bill, a keypad may be provided for operation by the user. Having manually identified for the processor 21 all of the fields on the image of bill, the interpretation of the field image is done in the same manner as analyzing a check or money order. The bill is verified, and if OK, the request is then stated as to the total amount to be paid for the transaction. The user then will receive the request to enter the amount to pay on the telephone bill, as shown in FIG. 20A, which in this instance, is $129.67. The service charge of $0.60 will be also displayed to the user on the user display 20 along with the total, which is shown in the window at the bottom of the screen 20. For instance, the total charge of $130.27 (FIG. 20A) to pay the particular telephone bill. When paying a telephone bill the screen 20 will then interrogate the user as to whether she wishes to pay another bill via an inquiry, such as the inquiry shown in FIG. 20C wherein it is desired to pay a gas bill of $45.22. The sum of $45.22 is entered by the user using the keyboard 18. As shown in FIG. 20D, the user is then prompted to load the gas bill into the scanner slot 54. The gas bill will be read in the same manner as the telephone bill was read by the cameras 58 and 60. The magnetic or the other optical character recognition information on the bill will be analyzed to associate the payment of $45.22 to the appropriate account to the bill paying network. If the user also decides to pay a gas bill, the user will press “continue”. Herein, the user decided to pay a credit card bill of $96.82 as shown in FIG. 20E for a third service charge of $0.60, which will bring the of the total service charges to $1.80. The total amount of the three bills, the telephone bill, the gas bill and the credit card bill plus the service charge will be $273.51. Next, the method of payment is requested (FIG. 20F); and if the user elects to pay with a credit card, she will press the keypad button 26b and cause the screen (FIG. 20G) to be shown on the user panel 20, requesting that the user insert the credit card bill into the slot 54. The bill payments have been made over the bills payment network and the bills will have been collected in the receiver bin. This process is set forth as shown in FIG. 20H. The bill payment process 720 is entered by selecting the type of bill such as telephone bill or electric bill, to be paid in a step 722. The bill is scanned and verified in a step 724 and the amount to be paid is entered manually in a step 726. A test is made in a step 728 to determine whether other bills are to be paid. If so, control is transferred back to step 722. If not, control is transferred to a step 730, testing for other transactions. A method of payment inquiry is made in a step 732 and in response thereto, a cash screen is displayed in a step 734, or a credit card payment screen is displayed in a step 736, or a smart card payment screen is displayed in a step 738, or a withdrawal screen is displayed in a step 740. After selecting the payment method, the funds are then transferred so that the bill is paid via modem connection in a step 742 and a receipt is printed out in a step 744. If another transaction is desired from step 730, the service option screen is displayed in a step 746. Otherwise, a test is made to determine if the card is in the card reader 22 in a step 748. The card is ejected in a step 750 and the welcome screen is displayed in a step 752. When finished with the bill payment, the screen display 20 shows that $273.51 has been withdrawn from the account in FIG. 20H with a notation that “your bills are paid.” As the flow chart for the bill payment shows in FIG. 20H, the receipt is printed by the receipt printer 50 which then ejects the receipt through the slot 52 to the user. The ATM card is then ejected from the card reader 22 back to the user. If the user had elected in FIG. 9 to buy lottery tickets, stamps or telephone calling cards, the purchase option would be selected by depressing the keypad button 27d to cause the purchase display screen of FIG. 21 to be present on the user display 20, which shows the option of buying stamps at $6.50 a booklet, a smart card at $5.00 a card, or a telephone card at $10.00 a card. Obviously, the number of items to be purchased could be enlarged to include lottery tickets or other end user items, which could be dispensed easily through purchasing goods dispensing slots 84, 85 and 86 shown in FIGS. 1 and 6 below three goods dispenser units comprising a lottery ticket dispenser 87, a stamp dispenser 88, a telephone calling card dispenser 89 and a smart card transaction vendor or handler 89a, all connected to the digital I/O board 62b via the resistor network 62a for communication with the computer 21. The disposed goods receiving slots 84, 85 and 86 are located in the front wall 16 of the housing 12, and the dispensers for the lottery tickets, stamps, telephone cards or smart card are mounted on dispenser support rails 90, as best seen in FIG. 3. The dispenser support rails 90 allow for sliding movement of the dispensers so that they can be accessed through a rear service door 94 (FIG. 7). The rear service door 94 has its own security lock 96 for denying unauthorized access to the interior of the housing 12 and to the goods dispensers 87, 88, 89 and 89a. A central door 97 having a security lock 98 can be opened to access the central portion of the machine 10 having the checks and the bills 66, the cameras 58 and 60, etc. While a variety of good dispensers could be used, the illustrated dispensers are card dispensers which are made by Asahi Seiko USA, Inc., Model CD1000. Manifestly, good dispensers may be used other than those card dispensers herein described by way of example. As shown in FIG. 21, the user may select one or more of the various items to be purchased. A telephone card may be selected by pushing the key 26c to select one $10.00 card. By pressing the “continue” button, the user is then provided with a screen display, as shown in FIG. 21B for buying smart cards or stamps. In the alternative the touch screen display shown in FIG. 21I can be used to make the selection by touching the appropriately labelled region of the screen display. In this instance, a three (five?) telephone calling card at $10.00 a card and three smart cards at $5.00 per card; have been selected by operating keypad button 26b to result in a grand total of $25.00 in purchases. The next screen to be shown on the display 20 prompts the user to select the method of payment for the $25.00 purchase. The user will then operate one of the keypads to select by cash, credit, withdrawal from account or smart card as a payment mode, as shown in FIG. 21C. In this instance, the operator has decided to pay with cash and has punched the arrow key 26a on the keypad 26. The screen shown in FIG. 21D will then be provided on the display 20 requesting the insertion of the cash into the cash acceptor slot 60. The cash is then verified as counted, FIG. 21E shows that the user has inserted only $20.00, which has been accepted by the cash acceptor 64 and counted. The screen will then show to the user in FIG. 21F that the payment of $21.00 is insufficient for the total transaction of $25.00. If the user only inserts another $3.00, the transaction screen will show that the payment is still $1.00 short, as shown in FIG. 21G wherein the transaction is $25.00. If another dollar bill is inserted into the machine 10, then the user will see the screen shown in FIG. 21H, which will inform the user to take his merchandise with him. Dispensing of the merchandise occurs as shown in the flow chart of FIG. 21A, and the machine control 21 operates the receipt printer 50 to print a receipt for the user which will be dispensed at the dispensing receipt slot 52. In order to make a purchase, the purchase process is entered in a step 770. The item to be purchased, such as smart card balance, telephone calling card, stamps or lottery tickets are selected in a step 772, or if desired, the transaction can be cancelled, causing control to be transferred to another transaction test step 774. When an item is chosen to be purchased such as a lottery ticket, the quantity of the item is prompted for in a step 776 and entered, and a test is made in a step 778 as to whether another purchase is to be made. If it is, control is transferred back to step 772. If not, in a step 780 the method of payment is selected, causing a cash payment screen to be displayed in a step 782 or a credit card screen to be displayed in a step 784, or a smart card payment screen to be displayed in a step 786 or a withdrawal screen to be displayed in a step 788, following which the funds are accepted and the merchandise, such as the lottery ticket, is dispensed, in a step 790. The receipt is printed in a step 792 and another transaction is tested for in the step 774. If another transaction is desired, the service options display screen is displayed in a step 794. If it is not, a test is made to determine if the card is in the card reader 22 in a step 796. The card is ejected in a step 798 and the welcome screen is displayed in a step 800. As above described herein, it is preferred not to have any coins or coin changers in the machine; and to provide $5.00 bills as the lowest denomination bills that will be paid out in change. Usually, the cash payment process will follow the flow chart shown in FIG. 22. In order to effect a cash payment for one of the transactions, such as the purchase of lottery tickets, transfer of a balance into the smart card or into a checking account or the like, the process is entered in a step 810 and the cash acceptor is initialized in a step 812. The currency is accepted in a step 814 and is totaled in a step 816. The accepted bills are stacked in the holding area in a step 818 and a test is made to determine whether the total covers the transaction amount in a step 820. If it does not, more money is accepted in a step 814. If the transaction is covered a determination is made in a step 822 whether change is due. If change is due, it is given in $5.00 increments with the remainder credited to the smart card in a step 824 and the transaction proceeds in a step 826. The $5.00 and $20.00 dollar bills available for change are stacked in the four cash bins. If the payment calculation shows that the cash tendered is sufficient for the transaction and that change is due, the change will be in cash in $5.00 increments by operation of the cash dispenser. Alternatively, any remaining change of less than $5.00 will be credited to a smart card or to a bank account to avoid the necessity of storing and handling small denomination bills and coins. The option will be exercised by the user with respect to change as shown on the screen display (FIG. 23). The user can insert a smart card into the card slot 14, and the smart card writer 89a (FIG. 1) will write the change by increasing the balance on the smart card, and then return the smart card to the user. If the user wants to deposit the change into her account, the user will operate arrow key 26b to cause the deposit transaction to occur over the banking network. Referring now to FIG. 26, in general, the system architecture as far as the document processing is set forth therein. An invoice image is captured in a step 1000 and a check image may be captured in a step 1002. The images are dissected in a step 1006 and a test is made to determine whether the fields within the image, such as the courtesy amount field or the legal amount field in a check or other image character recognition fields, for instance on bills, are valid, that is, can be interpreted as representing valid amount information or the like. Validation may proceed by selection from a variety of recognition engines, such as a numeric image character recognition engine in a step 1014, an alphabetical image character recognition engine in a step 1016, a courtesy amount recognition engine in a step 1018, a numeric optical character recognition engine in a step 1020, an alphabetic optical character recognition engine in a step 1022, a legal amount recognition engine in a step 1024, an optical magnetic ink character engine in a step 1026, or a magnetic ink character engine in a step 1028. The various recognition engines that have thus been selected pass their results, for instance, in terms of confidence levels, to the field validation step 1006. The field validation step then inputs information to a transaction arbitration step 1030. The transaction arbitration step 1030 may also receive entered field information from the step 1008 or other user-entered information such as user configuration information. Such user configuration information might include an ATM card number, an account number, a PIN number, or biometric data which is supplied to the transaction arbitration engine. The information is acted upon in accordance with rules in a rules DLL in a step 1032. An action, such as payment of a bill or dispensing of cash, takes place in a step 1034. Neural-network ICR engines trained from scratch by exposing the engine to a character training set consisting of thousands of discreet images of characters that point to their ASCII values. The ICR engine is then required to recognize a new set of characters that are not part of the new training set. Character images that are incorrectly recognized by the engine are assimulated into the original training set and the engine is retrained on the new set. This process is repeated until the accuracy of the engine meets certain predefined standards on arbitrary collections of real world image data, which standards are based upon comparable performance by professional data entry personnel. There are a number of character recognition engines that could be employed by CIRS. The ICR engines that could currently be used by CIRS include FieldScript and CheckScript, v2.2. by Parascript (Colorado Springs, Colo.) for LAR; Quickstrokes v2.4, by Mitek (San Diego, Calif.); OrboCAR v2.13, by OrboGraph (Israel) for CAR, and Wordscan Plus, 1998 edition, by Caere for OCR of machine print. Referring now to FIG. 27, in general, the types of transactions that may be performed by the apparatus 10 are set forth therein. All of these transactions relate to check processing. Remittance processing involving automated payment of a bill can occur in step a 1036. The remittance processing is followed by check processing in a step 1042. Arbitration and validation follows check processing in a step 1044. An action such as payment of the bill occurs in a step 1046. Proof of deposit may occur in a step 1038. Following which, check processing occurs in step 1042. The arbitration and validation step 1044, and the action step 1046 are then performed. Likewise, a payroll check may be cashed in a step 1040 involving check processing in step 1042. The arbitration and validation of the check processing information occurs in step 1044. The payroll in action step 1046 next takes place. Remittance processing details are more specifically shown in FIG. 28 wherein, in a step 1050, a user would be prompted to manually enter a full invoice amount, an amount to be paid and an account number at the apparatus 10. That information would be passed to a transaction arbitration step 1076. In addition, the check would be optically and magnetically scanned in a step 1052 to produce imaging of the front and back of the check as well as magnetic MICR information. The images from the check and the magnetic information would be dissected in a step 1054. Date amount recognition takes place in a step 1056. Legal amount recognition occurs in a step 1060. Courtesy amount recognition occurs in a step 1062. Each of those last three steps would then pass their results in terms of a confidence level or an output to the transaction arbitration step 1076. If an invoice is to be processed as part of the remittance, the invoice document is optically scanned in a step 1064 and the image is dissected in a step 1066. The image character recognition amount paid field is interpreted in a step 1068. The optical character recognition date field is interpreted in a step 1070. The account number, as sensed by optical character recognition in a step 1072, has its information passed to the transaction arbitration step 1076. In addition, the full invoice amount field is optical character recognized in step 1074, and that information is passed to the transaction arbitration step which then acts upon it and pays the bill in step 1078. Proof of deposit processing is performed as shown in FIG. 29. In a step 1080 the user is prompted to enter manually the amount of a check at the apparatus 10. The check is image scanned in a step 1082. The check image is dissected in a step 1084. Legal amount recognition takes place in a step 1086. Courtesy amount recognition takes place in a step 1088. Date recognition would take place in a step 1090. The results of steps 1086-1090 are passed to a transaction arbitration step 1092. The transaction arbitration step 1092 would then act in accordance with rules set forth in the rules module 1094. Action such as depositing funds and issuing a proof of deposit occur in a step 1096. As shown in FIG. 30, a payroll check may be cashed. In a step 1100, the user is prompted to enter the check amount into the apparatus 10. The entered amount is passed to a transaction arbitrator step 1112. In a step 1102, the check is optically scanned and in step 1104 an image of the check is dissected. In a step 1106 there is a magnetic recognition of the MICR line, for instance, to determine the bank number, the account number, and even in some instances the amount of the check. There is also optical recognition of the MICR line in a step 1108 and a date amount recognition in a step 1110. However, that information is passed to the transaction arbitration step 1112. Following step 1112, action, for instance, payment of funds, is taken in a step 1114. As shown in FIG. 31, details are set forth for the legal amount recognition and courtesy amount recognition arbitration procedures. A user enters the check amount in a step 1120. There is a cross-validation in a transaction arbitration step 1134. A check is optically scanned in a step 1122 and its image is dissected in a step 1124. The portion of the check image related to the courtesy amount is extracted in a step 1126 by way of bounding box recognition techniques set forth below. In a step 1127 the image is processed, including by way of character segmentation in a step 1128, and courtesy amount recognition values and associated confidence levels in output in a step 1130. The multiple courtesy amount recognition values may be output in step 1132 ranked according to their respective confidence levels. That information is passed to the transaction arbitration step 1134. In a similar fashion, the legal amount is extracted after image dissection in a step 1136. The image is processed in a step 1138, including via word segmentation in a step 1140, and the legal amount recognition conclusion is generated in step 1142. Multiple legal amount recognition values, together with their respective confidence levels, are transmitted in a step 1144 to the transaction arbitration step 1134. In a step 1150 an associated document, which may be a bill or invoice to be paid, will be optically scanned. The bill or invoice image will be dissected in a step 1152, and the image of the document amount is indicated possibly by a bounding box and extracted in step 1154. The document amount would be processed, including by character segmentation in a step 1158 and optical character recognition of the document amount in the step 1160. Document amount results are ranked by confidence level and transferred in a step 1162 to the transaction arbitration step 1134. In addition, after the associated document has been scanned, other amounts might be extracted required by the transaction and passed to the arbitration step 1134. The image would be extracted in step 1163a. The image would be processed in step 1163b. Character recognition would occur in step 1163c. Optical character recognition of other fields would occur in step 1163d. The resulting amounts or character strings would be ranked by confidence value in step 1163e. The arbitration step would act in accordance with various rules as to confidence levels and the like in step 1166 and take action, for instance, related to payment of an amount in a step 1168. As shown in FIG. 32, the image character recognition process occurs at a step 1170 in which the document is scanned, its image is processed in a step 1172, and relevant fields are located in a step 1174. Characters are segmented in a step 1176 and characters are classified in a step 1178. The document is scanned in the step 1170 by digitizing the image in a step 1180. During the image processing step 1172, the image is registered and deskewed in a step 1184. Extraneous lines are removed in step 1186 and noise is removed in step 1188. In order to determine the field location, whether by bounding boxes or the like, the field is matched in some instances with a predefined image character recognition template in a step 1190. In order to perform the character segmentation step 1176, features are extracted in a step 1194, a character string analysis is made in step 1196 and a best fit to a predefined number of characters is determined in step 1198. In order to perform character classification, context analysis is performed in step 1200, including by the use of dictionaries in step 1202 and look-up tables in a step 1204, which information is then relied upon by validation routines in step 1206. In order to generate a bounding box a bounding box procedure 1300 causes the processor, through the touch screen, to prompt the user to point to the beginning of a field such as a character amount field, a legal amount field, or some other field in a step 1302. Pointing at the touch screen causes the touch screen to signal the processor as to the X and Y coordinates of the point in a step 1304. In a step 1306 the processor is prompted to point to the end of the particular field. In a step 1308 the system records the X and Y coordinates of the end field point identified. In a step 1310 the X and Y coordinates of the initial point and the end point are used to define a region for an initial bounding box. In the step 1312 a pixel analysis routine to be described hereinafter determines whether significant portions of characters, strokes or the like extend outside the preliminary bounding box region. In a step 1314 the bounding box is then drawn on the screen and the user is prompted by the processor with a query as to whether they are satisfied with the bounds of the bounding box in a step 1316. If they are not, control is transferred back to step 1302 if they are, the bounding box is adopted in a step 1318 to define the region of interest to be operated upon by a recognition engine or recognition software which preforms optical character recognition, image character recognition, car recognition or the right. The bounding box may also be adjusted by a zooming procedure, as set forth in a zooming procedure 1330 shown in FIG. 34, in that procedure a document image is displayed on the touch screen in a step 1332. In a step 1334 the user is prompted to locate the field of interest by touching the screen. In a step 1336 the X and Y coordinates of the point touch are recorded in RAM. In a step 1338 the displayed image zooms in on the area around the point magnifying it. A test is made in a step 1340 to determine whether the zoom level is OK. If the user touches the screen further the process loops back to a step 1334 causing further zooming to take place. For instance the first zoom might magnify 1.8 times, the next zoom by 1.1, and successive zooms by smaller amounts so that there is a quasi-asymptotic approach without significant overshoot. Following completion of the zoom the bounding box procedure 1300 is entered by a step 1342. In order to preform the pixel analysis step 1312, as is shown in FIG. 35, the initial bounding box is generated on the basis of the user input as represented by a step 1360. In a step 1362 the area immediately surrounding the bounding box within half a character height is analyzed to determine whether portions of characters, cursive strokes or the like extend outside the bounding box region. If so, the bounding box borders are adjusted in a step 1364 to include the extraneous stroke portions within a somewhat larger bounding box. If there is a characteristic of characters which would be from a different field, as detected in a step 1366, the bounding box borders would be shifted to preclude inclusion of those characters within the field of interest. A test is made in a step 1368 to determine if field characters are not fully enclosed by the bounding box and then the borders would be moved so as to fully enclose all character in the field of interest in that step. The new bounding box would then be generated in the step 1370 and control would be transferred to step 1314 on FIG. 33 to draw the bounding box on the screen. Transaction arbitration for any of the above steps takes place as a result of the rules DLL which was provided and is depended thereon. Although variety of transaction arbitration sets of rules can be created for various environments, in one embodiment of the instant application, as is best shown in FIG. 36, the courtesy address recognition result in a step 1400 is passed to a rate of confidence algorithm in step 1402 which operates on it. The courtesy amount recognition threshold value for the confidence from the step 1404 is passed to a step to determine whether the rate of confidence is greater than threshold value in a step 1406. If it is not, the transaction is rejected in step 1408 and no further action is taken. If it is, control is passed to a step 1410 where rate of confidence algorithm is applied which receives the CAR recognition and CAR threshold as well as the numeric LAR recognition result related to the confidence level in the step 1412. If the overall confidence value is greater than the threshold in the step 1414 when taking into account the legal amount recognition threshold from step 1416, the transaction is accepted in a step 1418. If not, it is rejected in a step 1420. Description of Payroll Check Cashing Routine CIRS_ACTION CIRS_Rules_Payroll ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_CONFIG *pConfig) // Application specific parameters. { CIRS_RESULT MagMICR, OptMICR, CheckDate; int i, found; int Dollars, Cents; // Establish the list of candidates which pass threshold, for each field. CIRS_FilterByConf (&MagMICR, pCheck->MagMICR, pConfig->Check.MagMICR.Thresh); CIRS_FilterByConf (&OptMICR, pCheck->OptMICR, pConfig->Check.OptMICR.Thresh); CIRS_FilterByConf (&CheckDate , pCheck->Date, pConfig->Check.Date.Thresh); // Reject the transaction if there isn't at least one candidate for each field. if (MagMICR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (OptMICR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (CheckDate.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE // At least one good date candidate must be within the last 30 days. found = FALSE; for (i = 0; i < CheckDate.CandidateCount; i++) { if ((CheckDate.Candidates(i).Value.Date.Date < time (NULL) && (CheckDate.Candidates(i).Value.Date.Date > (time (NULL) − 60*60*24*30))) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_DATE); // At least one good candidate from the Optical MICR result must match the Magnetic MICR. Dollars = MagMICR.Candidates(0).Value.Amount.Dollars; Cents = MagMICR.Candidates(0).Value.Amount.Cents; found = FALSE; for (i = 0; i < OptMICR.CandidateCount; i++) { if ((OptMICR.Candidates(i).Value.Amount.Dollars == Dollars) && (OptMICR.Candidates(i).Value.Amount.Cents == Cents)) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_MICR); // Check the MICR amount and account against the database. if (! CIRS_ValidateMICR (MagMICR.Candidates(0), pEntered->Cash.Dollars)) return (CIRS_ACTION_BAD_CHECK_MICR); // Transaction is acceptable. return (CIRS_ACTION_ACCEPT); } Description of Remittance Processing Routine for Bill Payment The Rules DLL complies to the following API definition: // Confidence level for a char, word or field result. typedef U16 CIRS_CONF; // 0-1000. // Dollar amount field. typedef struct { U16 Dollars; // 0-9, 999. U8 Cents; // 0-99. CIRS_CONF Conf; // Amount confidence. } CIRS_AMOUNT; // Generic account field. May contain any application-specific characters, but would typically be digits. typedef char CIRS_ACCOUNT[20]; // CIRS specific date field. typedef struct { time_t Date; CIRS_CONF Conf; // Date confidence. } CIRS_DATE; // Image location coordinates for a char, word or field result. Measured in pixels. Coordinate systems // interpolation between devices is performed in the Field Validation Module. typedef struct { U16 x, y, dx, dy; // Device specific. } CIRS_SEGMENT; // A single character returned from a recognition engine. typedef struct { char Value; // [0-9A-Za-z{punct}]. CIRS_SEGMENT Segment; // Character location. CIRS_CONF Conf; // Character confidence. } CIRS_CHAR; // A single word returned from a recognition engine. typedef struct { CIRS_CHAR *Chars; // List of characters. U8 CharCount; // Number of chars in word. CIRS_SEGMENT Segment; // Word location. CIRS_CONF Conf; // Word confidence. } CIRS_WORD; // A single recognition candidate for a field. typedef struct { CIRS_WORD *Words; // List of words. U8 WordCount; // Number of words in field. CIRS_SEGMENT Segment; // Field location. CIRS_CONF Conf; // Field confidence. union { // Alternate representations. CIRS_AMOUNT Amount; // Only one of these will exist, CIRS_ACCOUNT Account; // determined by the data type CIRS_DATE Date; // of the field. } Value; } CIRS_CANDIDATE; // A complete recognition result for a field. typedef struct { CIRS_CANDIDATE *Candidates; // List of candidates. U16 CandidateCount; // Number of candidates. } CIRS_REC_RESULT; // Complete set of fields entered by the user at the system console. typedef struct { CIRS_AMOUNT Invoice; // Entered Invoice Amount. CIRS_AMOUNT Paid; // Entered Paid Amount. CIRS_ACCOUNT Account; // Entered Account. } CIRS_ENTERED; // Complete set of fields recognized from a check image. typedef struct { CIRS_REC_RESULT CAR; // Check CAR. CIRS_REC_RESULT LAR; // Check LAR. CIRS_REC_RESULT Date; // Check Date. CIRS_REC_RESULT Account; // Check Account. } CIRS_CHECK; // Complete set of fields recognized from an invoice image. typedef struct { CIRS_REC_RESULT Amount; // Invoice Amount. CIRS_REC_RESULT Paid; // Invoice Paid Amount. CIRS_REC_RESULT Date; // Invoice Date. CIRS_REC_RESULT Account; // Invoice Account. } CIRS_INVOICE; // All actions which can be returned from the Rules DLL. typedef CIRS_ACTION int; typedef enum { CIRS_ACTION_ACCEPT, // Good transaction. CIRS_ACTION_REJECT, // Generic failed transaction. CIRS_ACTION_BAD_CHECK_IMAGE, // Check image is poor. CIRS_ACTION_BAD_CHECK_CAR, // CAR can't be validated. CIRS_ACTION_BAD_CHECK_LAR, // LAR can't be validated. CIRS_ACTION_BAD_CHECK_DATE, // Check Date can't be validated. CIRS_ACTION_BAD_CHECK_ACCT, // Check Acct can't be validated. CIRS_ACTION_BAD_INVOICE— // Invoice image IMAGE, is poor. CIRS_ACTION_BAD_INVOICE— // Invoice Amt can't be AMOUNT, validated. CIRS_ACTION_BAD_INVOICE_PAID, // Invoice Paid can't be validated. CIRS_ACTION_BAD_INVOICE_DATE, // Invoice Date can't be validated. CIRS_ACTION_BAD_INVOICE_ACCT // Invoice Acct can't be } CIRS_ACTIONS; // Confidence threshold used for validating fields. Threshold values are determined experimentally, // based on a large set of sample images. Threshold values are customized for each application. typedef struct { CIRS_CONF Thresh; // 0-1000. } CIRS_CONF_CONFIG; // Set of thresholds for all fields on a check image. typedef struct { CIRS_CONF_CONFIG CAR; CIRS_CONF_CONFIG LAR; CIRS_CONF_CONFIG Date; CIRS_CONF_CONFIG Account; } CIRS_CHECK_CONFIG; // Set of thresholds for all fields on an invoice image. typedef struct { CIRS_CONF_CONFIG Amount; CIRS_CONF_CONFIG Paid; CIRS_CONF_CONFIG Date; CIRS_CONF_CONFIG Account; } CIRS_INVOICE_CONFIG; // Complete set of application specific thresholds. typedef struct { CIRS_CHECK_CONFIG Check; CIRS_INVOICE_CONFIG Invoice; } CIRS_CONFIG; // Single Rules DLL entry-point. extern CIRS_ACTION CIRS_Rules ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_INVOICE *pInvoice; // Invoice image recognition. CIRS_CONFIG *pConfig); // Application specific parameters. To facilitate the implementation of the Rules DLL, an API is provided which supports a basic set of CIRS related functions. The definition of the CIRS Support API follows: void CIRS_FilterByConf ( CIRS_REC_RESULT *pOutResult, CIRS_REC_RESULT InResult, CIRS_CONF Thresh); Remittance Processing CIRS_ACTION CIRS_Rules ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_INVOICE *pInvoice; // Invoice image recognition. CIRS_CONFIG *pConfig) // Application specific parameters. { CIRS_RESULT CAR, LAR, CheckDate, CheckAcct, InvPaid, InvAcct; int i, found; // Establish the list of candidates which pass threshold, for each field. CIRS_FilterByConf (&CAR, pCheck->CAR, pConfig->Check.CAR.Thresh); CIRS_FilterByConf (&LAR, pCheck->LAR, pConfig->Check.LAR.Thresh); CIRS_FilterByConf (&CheckDate , pCheck->Date, pConfig->Check.Date.Thresh); CIRS_FilterByConf (&CheckAcct , pCheck->Account, pConfig->Check.Account.Thresh); CIRS_FilterByConf (&InvPaid , pInvoice->Paid, pConfig->Invoice.Paid.Thresh); CIRS_FilterByConf (&InvAcct , pInvoice->Account, pConfig->Invoice.Account.Thresh); // Reject the transaction if there isnt at least one candidate for each field. if (CAR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (LAR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (CheckDate.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE if (CheckAcct.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (InvPaid.CandidateCount <= 0) return (CIRS_ACTION_BAD— INVOICE _IMAGE); if (InvAcct.CandidateCount <= 0) return (CIRS_ACTION_BAD— INVOICE _IMAGE); // At least one good date candidate must be within the last 15-days. found = FALSE; for (i = 0; i < CheckDate.CandidateCount; i++) { if ((CheckDate.Candidates(i).Value.Date.Date < time (NULL) && (CheckDate.Candidates(i).Value.Date.Date > (time (NULL) û 60*60*24*15))) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_DATE); // At least one good candidate from the CAR field must match the Entered Paid Amount. found = FALSE; for (i = 0; i < CAR.CandidateCount; i++) { if (CAR.Candidates(i).Value.Amount.Dollars == Entered.Dollars) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_CAR); // At least one good candidate from the LAR field must match the Entered Paid Amount. found = FALSE; for (i = 0; i < LAR.CandidateCount; i++) { if (LAR.Candidates(i).Value.Amount.Dollars == Entered.Dollars) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_LAR); // At least one good candidate from the Invoice Paid field must match the Entered Paid Amount. found = FALSE; for (i = 0; i < InvPaid.CandidateCount; i++) { if (InvPaid.Candidates(i).Value.Amount.Dollars == Entered.Dollars) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_INVOICE_PAID); // Transaction is acceptable. return (CIRS_ACTION_ACCEPT); } // Confidence level for a Char, word or field result. typedef U16 CIRS_CONF; // 0-1000. // Dollar amount field. typedef struct { U16 Dollars; // 0-9,999. U8 Cents; // 0-99.54. The Rules DLL Complies to the following API definition: // Confidence level for a Char, word or field result. typedef U16 CIRS_CONF; // 0-1000. // Dollar amount field. typedef struct { U16 Dollars; // 0-9,999. U8 Cents; // 0-99. CIRS_CONF Conf; // Amount confidence. } CIRS_AMOUNT; // Generic account field. May contain any application-specific characters, but would typically be digits. typedef char CIRS_ACCOUNT[20]; // CIRS specific date field. typedef struct { time_t Date; CIRS_CONF Conf; // Date confidence. } CIRS_DATE; // Image location coordinates for a char, word or field result. Measured in pixels. Coordinate systems // interpolation between devices is performed in the Field Validation Module. typedef struct { U16 x, y, dx, dy; // Device specific. } CIRS_SEGMENT; // A singe character returned from a recognition engine. typedef struct { char Value; // [0-9A-Za-z{punct}]. CIRS_SEGMENT Segment; // Character location. CIRS_CONF Conf; // Character confidence. } CIRS_CHAR; // A single word returned from a recognition engine. typedef struct { CIRS_CHAR *Chars; // List of characters. U8 CharCount; // Number of chars in word. CIRS_SEGMENT Segment; // Word location. CIRS_CONF Conf; // Word confidence. } CIRS_WORD; // A single recognition candidate for a field. typedef struct { CIRS_WORD *Words; // List of words. U8 WordCount; // Number of words in field. CIRS_SEGMENT Segment; // Field location. CIRS_CONF Conf; // Field confidence. union { // Alternate representations. CIRS_AMOUNT Amount; // Only one of these will exist, CIRS_ACCOUNT Account; // determined by the data type CIRS_DATE Date; // of the field. } Value; } CIRS_CANDIDATE; // A complete recognition result for a field. typedef struct { CIRS_CANDIDATE *Candidates; // List of candidates. U16 CandidateCount; // Number of candidates. } CIRS_REC_RESULT; // Complete set of fields entered by the user at the system console. typedef struct { CIRS_AMOUNT Invoice; // Entered Invoice Amount. CIRS_AMOUNT Paid; // Entered Paid Amount. CIRS_AMOUNT Cash; // Entered Check Amount. CIRS_ACCOUNT Account; // Entered Account. } CIRS_ENTERED; // Complete set of fields recognized from a check image. typedef struct { CIRS_REC_RESULT CAR; // Check CAR. CIRS_REC_RESULT LAR; // Check LAR. CIRS_REC_RESULT Date; // Check Date. CIRS_REC_RESULT Account; // Check Account. CIRS_REC_RESULT MagMICR; // Check Amount. CIRS_REC_RESULT OptMICR; // Check Amount. } CIRS_CHECK; // Complete set of fields recognized from an invoice image. typedef struct { CIRS_REC_RESULT Amount; // Invoice Amount. CIRS_REC_RESULT Paid; // Invoice Paid Amount. CIRS_REC_RESULT Date; // Invoice Date. CIRS_REC_RESULT Account; // Invoice Account. } CIRS_INVOICE; // All actions which can be returned from the Rules DLL. typedef CIRS_ACTION int; typedef enum { CIRS_ACTION_ACCEPT, // Good transaction. CIRS_ACTION_REJECT, // Generic failed transaction. CIRS_ACTION_BAD_CHECK_IMAGE, // Check image is poor. CIRS_ACTION_BAD_CHECK_CAR, // CAR can't be validated. CIRS_ACTION_BAD_CHECK_LAR, // LAR can't be validated. CIRS_ACTION_BAD_CHECK_DATE, // Check Date can't be validated. CIRS_ACTION_BAD_CHECK_ACCT, // Check Acct can't be validated. CIRS_ACTION_BAD_CHECK_MICR, // Check MICR can't be validated. CIRS_ACTION_BAD_CHECK_FRAUD, // Possibly fraudulent check. CIRS_ACTION_BAD_INVOICE_IMAGE, // Invoice image is poor. CIRS_ACTION_BAD_INVOICE_AMOUNT, // Invoice Amt can't be validated. CIRS_ACTION_BAD_INVOICE_PAID, // Invoice Paid can't be validated. CIRS_ACTION_BAD_INVOICE_DATE, // Invoice Date can't be validated. CIRS_ACTION_BAD_INVOICE_ACCT // Invoice Acct can't be validated. } CIRS_ACTIONS; // Confidence threshold used for validating fields. Threshold values are determined experimentally, // based on a large set of sample images. Threshold values are customized for each application. typedef struct { CIRS_CONF Thresh; // 0-1000. } CIRS_CONF_CONFIG; // Set of thresholds for all fields on a check image. typedef struct { CIRS_CONF_CONFIG CAR; CIRS_CONF_CONFIG LAR; CIRS_CONF_CONFIG Date; CIRS_CONF_CONFIG Account; CIRS_CONF_CONFIG MagMICR; CIRS_CONF_CONFIG OptMICR; CIRS_AMOUNT MaxCashed; } CIRS_CHECK_CONFIG; // Set of thresholds for all fields on an invoice image. typedef struct { CIRS_CONF_CONFIG Amount; CIRS_CONF_CONFIG Paid; CIRS_CONF_CONFIG Date; CIRS_CONF_CONFIG Account; } CIRS_INVOICE_CONFIG; // Complete set of application and user-specific parameters. typedef struct { CIRS_CHECK_CONFIG Check; CIRS_INVOICE_CONFIG Invoice; } CIRS_CONFIG; // Entry point for rules related to remittance processing. extern CIRS_ACTION CIRS_Rules_Remittance ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_INVOICE *pInvoice; // Invoice image recognition. CIRS_CONFIG *pConfig); // Application specific parameters. // Entry point for rules related to payroll check cashing.. extern CIRS_ACTION CIRS_Rules_payroll ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_CONFIG *pConfig); // Application specific parameters. // Entry point for rules related to proof of deposit.. extern CIRS_ACTION CIRS_Rules_POD ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_CONFIG *pConfig); // Application specific parameters. To facilitate the implementation of the Rules DLL, an API is provided which supports a basic set of CIRS related functions. The definition of the CIRS Support API follows: void CIRS_FilterByConf ( CIRS_REC_RESULT *pOutResult, CIRS_REC_RESULT InResult, CIRS_CONF Thresh); void CIRS_SortByConf ( CIRS_REC_RESULT *pOutResult, CIRS_REC_RESULT InResult); int CIRS_ValidateMICR ( CIRS_CANDIDATE MICR, CIRS_AMOUNT Amount); Remittance Processing CIRS_ACTION CIRS_Rules_Remittance ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_INVOICE *pInvoice; // Invoice image recognition. CIRS_CONFIG *pConfig) // Application specific parameters. { CIRS_RESULT CAR, LAR, CheckDate, CheckAcct, InvPaid, InvAcct; int i, found; // Establish the list of candidates which pass threshold, for each field. CIRS_FilterByConf (&CAR, pCheck->CAR, pConfig->Check.CAR.Thresh); CIRS_FilterByConf (&LAR, pCheck->LAR, pConfig->Check.LAR.Thresh); CIRS_FilterByConf (&CheckDate , pCheck->Date, pConfig->Check.Date.Thresh); CIRS_FilterByConf (&CheckAcct , pCheck->Account, pConfig->Check.Account.Thresh); CIRS_FilterByConf (&InvPaid , pInvoice->Paid, pConfig->Invoice.Paid.Thresh); CIRS_FilterByConf (&InvAcct , pInvoice->Account, pConfig->Invoice.Account.Thresh); // Reject the transaction if there isnt at least one candidate for each field. if (CAR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (LAR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (CheckDate.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE if (CheckAcct.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (InvPaid.CandidateCount <= 0) return (CIRS_ACTION_BAD— INVOICE_IMAGE); if (InvAcct.CandidateCount <= 0) return (CIRS_ACTION_BAD— INVOICE_IMAGE); // At least one good date candidate must be within the last 15-days. found = FALSE; for (i = 0; i < CheckDate.CandidateCount; i++) { if ((CheckDate.Candidates(i).Value.Date.Date < time (NULL) && (CheckDate.Candidates(i).Value.Date.Date > (time (NULL) û 60*60*24*15))) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_DATE); // At least one good candidate from the CAR field must match the Entered Paid Amount. found = FALSE; for (i = 0; i < CAR.CandidateCount; i++) { if (CAR.Candidates(i).Value.Amount.Dollars == pEntered->Paid.Dollars) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_CAR); // At least one good candidate from the LAR field must match the Entered Paid Amount. found = FALSE; for (i = 0; i < LAR.CandidateCount; i++) { if (LAR.Candidates(i).Value.Amount.Dollars == pEntered->Paid.Dollars) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_LAR); // At least one good candidate from the Invoice Paid field must match the Entered Paid Amount. found = FALSE; for (i = 0; i < InvPaid.CandidateCount; i++) { if (InvPaid.Candidates(i).Value.Amount.Dollars == pEntered->Paid.Dollars) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_INVOICE_PAID); // Transaction is acceptable. return (CIRS_ACTION_ACCEPT); } Payroll Check Cashing CIRS_ACTION CIRS_Rules_Payroll ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_CONFIG *pConfig) // Application specific parameters. { CIRS_RESULT MagMICR, OptMICR, CheckDate; int i, found; int Dollars, Cents; // Establish the list of candidates which pass threshold, for each field. CIRS_FilterByConf (&MagMICR, pCheck->MagMICR, pConfig->Check.MagMICR.Thresh); CIRS_FilterByConf (&OptMICR, pCheck->OptMICR, pConfig->Check.OptMICR.Thresh); CIRS_FilterByConf (&CheckDate , pCheck->Date, pConfig->Check.Date.Thresh); // Reject the transaction if there isnt at least one candidate for each field. if (MagMICR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (OptMICR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (CheckDate.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE // At least one good date candidate must be within the last 30 days. found = FALSE; for (i = 0; i < CheckDate.CandidateCount; i++) { if ((CheckDate.Candidates(i).Value.Date.Date < time (NULL) && (CheckDate.Candidates(i).Value.Date.Date > (time (NULL) u 60*60*24*30))) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_DATE); // At least one good candidate from the Optical MICR result must match the Magnetic MICR. Dollars = MagMICR.Candidates(0).Value.Amount.Dollars; Cents = MagMICR.Candidates(0).Value.Amount.Cents; found = FALSE; for (i = 0; i < OptMICR.CandidateCount; i++) { if ((OptMICR.Candidates(i).Value.Amount.Dollars == Dollars) && (OptMICR.Candidates(i).Value.Amount.Cents == Cents)) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_MICR); // Check the MICR amount and account against the database. if (! CIRS_ValidateMICR (MagMICR.Candidates(0), pEntered->Cash.Dollars)) return (CIRS_ACTION_BAD_CHECK_MICR); // Transaction is acceptable. return (CIRS_ACTION_ACCEPT); } Proof of Deposit CIRS_ACTION CIRS_Rules_POD ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_CONFIG *pConfig) // Application specific parameters. { CIRS_RESULT CAR, LAR, CheckDate; int i, found; int BestCAR, BestLAR; // Establish the list of candidates which pass threshold, for each field. CIRS_FilterByConf (&CAR, pCheck->CAR, pConfig->Check.CAR.Thresh); CIRS_FilterByConf (&LAR, pCheck->LAR, pConfig->Check.LAR.Thresh); CIRS_FilterByConf (&CheckDate , pCheck->Date, pConfig->Check.Date.Thresh); // Reject the transaction if there isnt at least one candidate for each field. if (CAR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (LAR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (CheckDate.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE // At least one good date candidate must be within the last 30 days. found = FALSE; for (i = 0; i < CheckDate.CandidateCount; i++) { if ((CheckDate.Candidates(i).Value.Date.Date < time (NULL) && (CheckDate.Candidates(i).Value.Date.Date > (time (NULL) û 60*60*24*30))) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_DATE); // At least one good candidate from the CAR field must match the Entered Amount. found = FALSE; for (i = 0; i < CAR.CandidateCount; i++) { if (CAR.Candidates(i).Value.Amount.Dollars == pEntered->Paid.Dollars) { found = TRUE; BestCAR = i; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_CAR); // At least one good candidate from the LAR field must match the Entered Amount. found = FALSE; for (i = 0; i < LAR.CandidateCount; i++) { if (LAR.Candidates(i).Value.Amount.Dollars == pEntered->Paid.Dollars) { found = TRUE; BestLAR = i; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_LAR); // Detect possible check tampering. if ((CAR.Candidates(BestCAR).Conf > CarFraudMin) && (LAR.Candidates(BestLAR).Conf − LAR.Candidates(BestLAR).Words(0).Conf > LarFraudSpread)) return (CIRS_ACTION_BAD_CHECK_FRAUD); // Transaction is acceptable. return (CIRS_ACTION_ACCEPT); Proof of Deposit CIRS_ACTION CIRS_Rules_Payroll ( CIRS_ENTERED *pEntered; // Fields entered by the user. CIRS_CHECK *pCheck; // Check image recognition. CIRS_CONFIG *pConfig) // Application specific parameters. { CIRS_RESULT MagMICR, OptMICR, CheckDate; int i, found; int Dollars, Cents; // Establish the list of candidates which pass threshold, for each field. CIRS_FilterByConf (&MagMICR, pCheck->MagMICR, pConfig->Check.MagMICR.Thresh); CIRS_FilterByConf (&OptMICR, pCheck->OptMICR, pConfig->Check.OptMICR.Thresh); CIRS_FilterByConf (&CheckDate , pCheck->Date, pConfig->Check.Date.Thresh); // Reject the transaction if there isn't at least one candidate for each field. if (MagMICR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (OptMICR.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE); if (CheckDate.CandidateCount <= 0) return (CIRS_ACTION_BAD_CHECK_IMAGE // At least one good date candidate must be within the last 30 days. found = FALSE; for (i = 0; i < CheckDate.CandidateCount; i++) { if ((CheckDate.Candidates(i).Value.Date.Date < time (NULL) && (CheckDate.Candidates(i).Value.Date.Date > (time (NULL) − 60*60*24*30))) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_DATE); // At least one good candidate from the Optical MICR result must match the Magnetic MICR. Dollars = MagMICR.Candidates(0).Value.Amount.Dollars; Cents = MagMICR.Candidates(0).Value.Amount.Cents; found = FALSE; for (i = 0; i < OptMICR.CandidateCount; i++) { if ((OptMICR.Candidates(i).Value.Amount.Dollars == Dollars) && (OptMICR.Candidates(i).Value.Amount.Cents == Cents)) { found = TRUE; break; } } if (! found) return (CIRS_ACTION_BAD_CHECK_MICR); // Check the MICR amount and account against the database. if (! CIRS_ValidateMICR (MagMICR.Candidates(0), pEntered->Cash.Dollars)) return (CIRS_ACTION_BAD_CHECK_MICR); // Transaction is acceptable. return (CIRS_ACTION_ACCEPT); It will be appreciated that although various aspects of the invention have been described with respect to specific embodiments, alternatives and modifications will be apparent from the present disclosure, which are within the spirit and scope of the present invention as set forth in the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The invention relates to automated banking systems and machines including those which employ or are an improvement over automatic teller machines (ATMs). The invention also relates to providing such ATMs with sufficient security confidence levels with respect to the user, to the document, and to the bank parameters and rules that cash can be securely dispensed to the user as a result of the cashing of payroll or third party remittances or the paying of bills. The confidence levels should be such as would normally be achieved or approach those in comparable transactions with a teller. A number of security problems arise with the addition to ATMs of functions performed by full service banks and currency exchanges. Such functions include cashing checks and money orders, paying bills, or handling a cash equivalent transaction, such as making a deposit into a bank account. When the bank is to cover such checks and dispense cash to the user, the bank requires validation of the user identity, validation of the genuineness of the document, validation of the amount(s) set forth on the document, validation of a signature on the document, validation of an endorsement when needed, validation of the bank parameters or rules, etc. To date, ATMs have been unable to provide such validations with a reliability sufficient to cash many documents without the presence of a teller. To provide an acceptable confidence level to the bank with respect to user validation prior to dispensing cash, a minimum requirement is the use of an ATM card, smart card, or the like, and a password such as a PIN number. The machine could read these, as in conventional machines. In accordance with the preferred embodiments of the present invention, a biometric check also is provided to assure that the person using the machine is a qualified user. This involves extracting recognition features from the user and preferably biometric features such as voice characteristics or features, facial recognition features, retinal features; fingerprint features, palm features; and/or signature features or the like. The qualified user will have previously provided such features to the bank system where they are stored for comparison to the extracted features of the person using the machine. The results comparison must reach certain confidence levels that can be set and/or adjusted by the bank to its satisfaction. Thus, if provided with confidence threshold levels as to card, password and/or the biometric features, the bank can be reasonably assured that the AIM user is a qualified user. With respect to document validation including the amount of document such as the pay amount of the remittance, a number of validation techniques are desired. To assure that the document being cashed is the original and not merely a photocopy of a valid check having a MICR line thereon, the MICR line should be tested to ascertain that a sufficient magnetic field is present at the MICR line position. Another validation that is desired is a reading of the MICR line contents and communicating to the banking system that a bank number and an account number for the identified bank refer to a real rather than a fictitious bank or account. Additionally, for checks, it is desired to be able to read the CAR amount and the LAR amount and to compare the same to detect whether or not the CAR line has been changed, for example, a “1” has been changed to a “4” or a “7” by merely adding pen strokes to the “1”. Other validations can be used and obtained to guard against violation of bank parameters or rules. Another significant document validation procedure with respect to checks is a determination that a signature is present. That is, the check is signed at the signature line. Going even further, it would be helpful to establish some acceptable signature confidence level by comparison of the signature against a stored signature of the user in instances where the user is signing a check or endorsing the back of the check. Also, in transactions where the check needs to be endorsed, there should be a validation by the machine that a signature is present at the endorsement line. Also, there may be a step of comparing a signature against a stored signature of the endorser. When improper payments are made to the user if the transactional is fraudulent, it is an important security feature to be able to prove that the user had an intent to defraud the bank. Absent such proof of fraudulent intent, the user may escape civil or criminal liability by claiming that such improperly dispensed cash or cash equivalent was a solely due to the fault of the ATM or banking system and not attributable to the user. That is, the user may claim he did not intentionally cause the cash dispensed or dispensed in an amount to be larger than that to which he was entitled and that there was no culpability on his part for the amount of cash dispensed to him. The wide variety of checks, money orders and bills presents a still further problem with transactions involving cashing of checks or the like, depositing funds to an account, or paying bills. As to each document, the location of the data fields to be analyzed may be different. Preferably, the ATM machine should be able to process large amount payroll checks, smaller amount personal checks, and bills having a bill pay amount located at various places on the bill. Preferably, a cash or cash equivalent dispensing system used without a human teller also is able to meet various bank parameters or rules. Often there is a transaction maximum limit, which may be customized as to the drawer of the check issuer or the payee. The bank may have cash payout limits on a daily or other time basis that should be met with sufficient confidence before dispensing cash. The bank may also have check date rules with respect to processing antedated or post-dated checks that should be satisfied. Finally, the bank may want to set its own thresholds with respect to confidence levels with respect to the identity of the user and validation of document. The system should be able to meet the satisfaction levels desired by the bank, and to be able to adjust such levels for a given transaction, type of transaction, or different validations. Another consideration for transactions such as cashing checks, paying bills, or other like things from a remote banking machine is the need to make a record and to leave an audit trail for later manual review, if required, of the transaction. Among some of the mechanical problems that have been experienced with the remote ATM-type machines is that of providing change in coins or small bills. Already, over a single weekend, ATMs are being severely taxed often to the point that they are completely emptied of their cash contents. In addition, ATMs do not have change makers. When cashing checks, money orders or returning change from a cash bill payment, the ATM must be able to return to the user the exact amount. If the exact amount is in cash, the addition of a coin change maker and small denomination bill dispenser adds considerable expense and maintenance problems to the machine. This would be necessitated to provide the exact change, including coins, to the user who is cashing a check or performing some other function, such as paying a bill with cash from which change is due. The situation is aggravated when the ATM is performing transactions that include an automatic fee calculation and deduction of the fee because there will usually be change due for any cash payout after the transaction fee deduction. Another problem with providing a commercially practical automated banking machine is that of the time needed for the transactions. Preferably, the transactions should be relatively brief and simple so that a minimal number of operator actions, such as touch screen pushes or keystrokes, are required for each transaction. If a particular transaction takes more than a minute or two, the system would probably be too slow to adequately service a line of people waiting to use the machine at a busy time, for instance on a weekend. Also, if the machine is able to process a large number of different types of transactions like those of a full-service bank or a currency exchange, the machine should provide the user a wide range of funds-delivery or payment options so that the payment can be made in cash, by credit card, by smart card, or by withdrawal from a checking or savings account. Even if an ATM existed for paying bills or processing checks of various amounts, that ATM might have difficulty in automatically locating, reading or interpreting amount lines such as the CAR or LAR, an invoice account number, the amount of the invoice, the amount to be paid, etc. without assistance from the user. Often the numbers written, typed or printed in such lines are relatively small. They might need to be accurately separated from any other writing or numbers to provide a secure and accurate execution of the desired transaction for the document being read. To this end, there is a need for an efficient system or method to locate, read, and interpret such lines with a manual input from the user. There is a need for an automatic banking machine which includes an ATM-like machine that performs and allows a number of service options, such as for example the withdrawing of cash, the deposit of cash, the cashing of a check, the cashing of a money order, the purchase of a money order, the transfer of funds by wire, payment of a bill and purchase of end user items. | <SOH> SUMMARY OF THE INVENTION <EOH>In accordance with the present invention, there is provided an automated banking system including one or more machines which perform the usual ATM functions, but also have such significant security safeguards that they allow the cashing of monetary transaction documents such as checks or money orders, or handling of cash equivalent transactions such as making a deposit in the bank account of the user, without the aid of a teller. These functions are achieved by having sufficient validation of the identity of the user, validation of document, such as being a signed or endorsed check or the like, validation of the amount to be paid in cash or deposited, and validation of the banking system parameters or rules for the customer and/or transaction. With respect to validation of the personal identity of the ATM user, a first, minimal fraud protection procedure is to verify that the ATM card and/or the user, as presented at the machine, is associated with a qualified password or PIN number that, upon entry, validates the user as a qualified user. Preferably, and in accordance with the invention, an additional biometric comparison or recognition function is made between extracted features of the user such as face features, voice features, retina features, fingerprint features, palm features, handwriting features for signature verification, etc. In the present invention, the identity of the user is preferably validated with sufficient levels of confidence that cash will be dispensed if the other validation techniques are also satisfied. The bank will have its own rules with respect to how large a transaction will be permitted for the particular user, particularly with respect to the dispensing of cash to the user. In the preferred embodiment of the invention, the validation of the document preferably includes the extraction of data to compare the LAR amount and the CAR amount. In instances where the check to be negotiated includes a magnetic ink character recognition (MICR) line amount for the amount of the check, the MICR line may be read and a comparison of the LAR to the CAR is not needed. Additionally, other validation methods for checks may be provided and practiced such as validation that magnetic ink is present on the MICR line and that bank and account numbers are recognized as being valid within the banking system computer system. To prove that the user intentionally requested the amount of cash being dispensed, the user must manually enter amounts using a manual entry device at the ATM, e.g., the pay amount of the check, so that user will not be able to contend later that a machine error caused a specific payment to him. A part of the proof of the intentional request yielded by scanning the check and presenting a computer-generated image of the check to the user and prompting the user to enter the payable amount via an entry device. A still further validation technique is used in the preferred embodiment of the invention to safeguard the assets of the bank. Banks may have their own set of parameters or rules governing payouts and other transactions that must be validated. For example, validation techniques are used to assure that the amount of cash being paid out is equal or less than the transaction or daily limit for the user and the bank is satisfied with paying out those amounts based on credit history of user. In accordance with a further aspect of the invention, the bank will receive a validation that a signature is present at the signature line of the document, such as a check, before performing the requested financial transaction with respect to the check. To this end, the signature line is located and an analysis is made to an acceptable confidence level that a signature is present at the signature line. If a signature is lacking, the check will be rejected. Preferably, an analysis will be made as to verify the user's signature against stored user signatures to provide an additional security check to provide further confidence to the bank doing the transaction. Machine protection against a skilled forgery is difficult with current technology; nonetheless, unskilled forgeries or ambiguous signatures may still be detected. In instances where a third-party check or money order is to be processed and the ATM user must endorse the instrument, it is preferred to locate the endorsement line and at least validate that an endorsement is present in order to protect the receiving bank and others in the check reconciliation process against certain types of claims. Again, if the user has signatures of record, the endorsement can be compared to the signatures of record and a confidence level validation can be achieved if the transaction is to be completed. In the preferred ATM machine, the user manually selects the transaction, for instance from a list of transactions including check cashing, check deposit, bill payment, etc. The user then further operates the machine by inserting the document into the machine to cause a computer generated image to be seen by the user and to allow for analysis of features of the document image reflective of the document's contents. Because of the wide variety of document sizes and the variety of locations of the amount line or lines such as CAR, LAR or bill payment due, it is preferred to prompt the user to locate the coordinates of and/or to bound one or more fields for analysis and validation. These fields may include a date field, a CAR field, a LAR field, an amount field, an account number or MICR line field. If the document fails to meet the threshold validity for any one or more of these bounded fields, further transaction processing is aborted without any cash being dispensed to the user. In accordance with a further aspect of the invention, the ATM user is prompted by the display and the display provides a bounding box image. The bounding box can be adjusted by the user who then accepts or rejects with respect to a particular line. The accepted line in the bounding box is machine interpreted by OCR or some other image processing technique or the like. Typically, account numbers for bills and the amount of the bill to be paid are located often arbitrarily at various places. They are difficult to locate and must be precisely delineated from other adjacent typing, printing, letter or cursive to allow the transaction to be accomplished. In a preferred embodiment of the invention, the user is prompted to touch a touch screen display at the desired location, e.g., the account number on an invoice. The user then has the option of “tweaking” or adjusting the bounding box to cover only the desired information. The user is prompted to point to the general area of the document image that contains the information, such as an account number or an amount, to be bounded. The identified region would have its image zoomed on the screen. The first zoom step might be 1.8× linear magnification with the next step 1.1×. The magnification factor would decrease for each additional step to help avoid zoom overshoot. When zooming has been completed, the user would so indicate to the machine and then would be prompted to define the bounding box. This would be done in part by pointing to the beginning and the end of the area of interest. After this first bounding box is generated, a pixel analysis routine would be executed in the pixels at the bounding box borders. This would help ensure that no stray or extraneous characters were inadvertently included in the bounding box leading possibly to a spurious result from later analysis of the data contents of the bounding box. Finally, the user would indicate her acceptance or rejection of the final bounding box, which might change color for clarity, by appropriate keystrokes or touch screen entries or the like. This technique would avoid problems of lack of bounding box resolution due to a user's finger obscuring a feature of interest during box definition. An alternative bounding box technique would require the user to trace her finger around the region of interest thereby enclosing it rather than simply identifying the beginning and the end of the field. In order to assist the user the ATM provides prompts to the user and has buttons or touch screen areas that allow the user to switch back to the menu screen to begin again. In the alternative they would allow the user to undo the current screen and go back one screen to make a revision or the like where appropriate. When processing a monetary transaction document for routine bill paying, it is preferred to provide a validation of the bill, the user and the monetary transaction document being used to pay the bill or a portion thereof. With a bill-paying transaction, an operative assumption may be made that where no cash or cash equivalent is being paid out to the user, that user lacks an incentive to misrepresent the pay amount on the checks or the like. In the paying of bills, the user will select the bill payment transaction from a list of transactions. The user will be prompted to make one or more manual entries into machine, like the amount of the bill, the amount being paid by the user which should be equal to or less than the check; and the user's account number on the bill. The machine will scan and interpret the user's account number on the bill, the full amount due, and the date field. If the amount being paid is other than the full amount of the bill, a prompt to enter the tendered amount is provided to user on a screen or the like. When the amount of the check or the like from which the funds are derived is greater than the amount being paid, the user may be prompted to have the remainder of the funds paid in cash or loaded into a balance of a debit or a smart card. When paying a bill or making a deposit, the amount field of the document is analyzed on the bill or the deposit slip and compared to the amount manually entered by the machine user. This provides one validation procedure. In some instances, when cashing or depositing a document such as a check, the drawer of the check may have indicated the amount of the check at a MICR line. For example, large employers may issue authorized payroll checks for its enrolled employees. Those payroll checks are issued with a MICR line having the amount of the check thereon. In such instances, the MICR amount line may be read and used to validate the document and the amount to be paid without any comparison of CAR and LAR lines, as is the case for checks that lack a MICR amount thereon. In accordance with an important aspect of the invention, the check, money order or the like is scanned and an image therefrom is dissected with extracted image information being obtained for several recognition fields. The recognition fields are processed to provide a list of amount results ranked by confidence values. The user-entered amount and these confidence values are provided to a processor for transaction arbitration involving cross-validation according to rules. If there is validation of the arbitration using the rules, the transaction is then taken, such as cashing a check, paying a bill, or making a deposit. The usual recognition fields for a check are the LAR and CAR. When a remittance document is also provided to the ATM machine for paying a bill or the like, the remittance document is scanned and its image dissected with one recognition making a deposit field being the amount for the remittance. A list of amount results are ranked by confidence levels and they are provided to the processor for transaction arbitration under the rules. The remittance amount is cross-validated with the check amount results in the transaction arbitration; and, upon validation, the remittance transaction action then proceeds to completion. | 20040712 | 20100126 | 20050217 | 99307.0 | 10 | CAMPEN, KELLY SCAGGS | AUTOMATED DOCUMENT CASHING SYSTEM | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,889,488 | ACCEPTED | Transformable toy | A transformable toy including a first movable member, a second movable member and a coupler positioned between and coupled to the first and second movable members. The coupler is adapted to enable the first and second movable members to independently move or pivot towards each other to a closed position and away from each other to a substantially open position. The first and second movable members include at least one revealer. The revealer is movably connected to one of the first and second movable members and is movable to reveal at least one surface when the first and second movable members are in the open position. In one embodiment, the toy forms a ball in the closed position and a figurine in the open position. | 1. A toy comprising: a first movable member; a second movable member positioned adjacent to said first movable member, said second movable member being hingedly connected to said first movable member, wherein the first movable member and the second movable member are moved away from each other to an open position or towards each other to a closed position; and a display member connected to a surface of at least one of the first and second movable members, wherein the display member is revealed when the first and second movable members are in the open position. 2. The toy of claim 1, which includes a coupler positioned between said first and second movable members, said first movable member being movably connected to one end of the coupler and said second movable member being movably connected to an opposite end of the coupler. 3. The toy of claim 1, wherein said display member includes a revealer movably connected to at least one of said first movable member and said second movable member 4. The toy of claim 3, wherein the revealer forms a head and a surface of the head includes a face. 5. The toy of claim 1, wherein said display member includes a plurality of revealers rotatably connected to at least one of the first and second movable members. 6. The toy of claim 5, wherein the revealers each include at least one surface having an image formed thereon. 7. The toy of claim 1, wherein the first movable member and the second movable member each have a generally semi-circular shape. 8. The toy of claim 1, which includes a lock connected to at least one of the first and second movable members, wherein said lock is adapted to releasably secure the first and second movable members together. 9. The toy of claim 1, wherein the first movable member and the second movable member each have a generally cubic shape. 10. A toy comprising: a first movable member; a second movable member positioned adjacent to said first movable member, said second movable member being hingedly connected to said first movable member; moving means positioned between said first and second movable members for enabling the first movable member and the second movable member to move away from each other to an open position or toward each other to a closed position; and a display member connected to a surface of at least one of the first and second movable members, wherein the display member is revealed when the first and second movable members are in the open position. 11. The toy of claim 10, wherein the moving means includes a coupler positioned between said first and second movable members, said first movable member being movably connected to one end of the coupler and said second movable member being movably connected to an opposite end of the coupler. 12. The toy of claim 10, wherein said display member includes a revealer movably connected to at least one of said first movable member and said second movable member 13. The toy of claim 12, wherein the revealer forms a head and a surface of the head includes a face. 14. The toy of claim 10, wherein said display member includes a plurality of revealers rotatably connected to at least one of the first and second movable members. 15. The toy of claim 14, wherein the revealers each include at least one surface having an image formed thereon. 16. The toy of claim 10, wherein the first movable member and the second movable member each have a generally semi-circular shape. 17. The toy of claim 10, which includes a lock connected to at least one of the first and second movable members, wherein said lock is adapted to releasably secure the first and second movable members together. 18. The toy of claim 10, wherein the first movable member and the second movable member each have a generally cubic shape. 19. A toy comprising: a first movable member; a second movable member positioned adjacent to said first movable member; a coupler positioned between said first and second movable members, said first movable member being movably connected to one end of the coupler and said second movable member being movably connected to an opposite end of the coupler, wherein the first movable member and the second movable member are moved away from each other to an open position or towards each other to a closed position; and a revealer movably connected to at least one of said first movable member and said second movable member, wherein the revealer is moved to reveal at least one surface of the revealer when the first and second movable members are in the open position. 20. The toy of claim 19, wherein the first movable member and the second movable member each have a generally semi-circular shape. 21. The toy of claim 19, wherein the revealer forms a head and a surface of the head includes a face. 22. The toy of claim 19, which includes a plurality of revealers rotatably connected to at least one of the first and second movable members. 23. The toy of claim 22, wherein the revealers each include at least one surface having an image formed thereon. 24. The toy of claim 19, which includes a lock connected to at least one of the first and second movable members, wherein said lock is adapted to releasably secure the first and second movable members together. 25. The toy of claim 19, wherein the first movable member and the second movable member each have a generally cubic shape. 26. A toy comprising: a first movable member; a second movable member positioned adjacent to said first movable member; moving means positioned between said first and second movable members for enabling the first movable member and the second movable member to move away from each other to an open position or towards each other to a closed position; and revealing means for revealing at least one image, said revealing means connected to at least one of said first movable member and said second movable member, wherein the revealing means reveals at least one image when the first and second movable members are in the open position. 27. The toy of claim 26, wherein the first movable member and the second movable member each have a generally semi-circular shape. 28. The toy of claim 26, which includes a plurality of revealing means connected to at least one of the first and second movable members. 29. The toy of claim 28, wherein the plurality of revealing means each include at least one surface having an image formed thereon. 30. The toy of claim 26, which includes a lock means for releasably securing the first and second movable members together when the first and second movable members are in the closed position. 31. A toy comprising: a first movable member; a second movable member positioned adjacent to said first movable member; a coupler positioned between said first and second movable members, said first movable member being movably connected to one end of the coupler and said second movable member being movably connected to an opposite end of the coupler, wherein the first movable member and the second movable member are moved away from each other to an open position or towards each other to a closed position; a head movably connected to the first movable member; a body positioned adjacent to the head and mounted to an inside surface of the first movable member; at least one arm positioned on opposing sides of the body and movably connected to said body; a support connected to an inside surface of the second movable member; and a base positioned adjacent to the support and movably connected to said second movable member, wherein the head, arms and the base are independently movable from a retracted position to a revealed position when the first and second movable members are in the open position, and wherein the head, arms and the base are independently movable from the revealed position to the retracted position when the first and second members are in the closed position. 32. The toy of claim 31, wherein the first movable member and the second movable member each have a generally semi-circular shape. 33. The toy of claim 31, wherein at least one surface of the head includes a face. 34. The toy of claim 31, which includes a lock connected to at least one of the first and second movable members, wherein said lock is adapted to releasably secure the first and second movable members together. 35. The toy of claim 31, wherein the first movable member and the second movable member each have a generally cubic shape. 36. The toy of claim 31, wherein the base includes a receptacle which is formed to matingly engage the head when the first and second movable members are in the closed position. | BACKGROUND OF THE INVENTION Toys provide excitement and enjoyment for children. Toys come in several different sizes, shapes, configurations and perform many different functions. Some toys have a limited number of functions. Toys with a limited number of functions or uses tend to quickly lose childrens' interest. Accordingly, there is need for toys with multiple functions and different uses to enhance childrens' excitement, enjoyment and interest with the toys. SUMMARY OF THE INVENTION The present invention generally refers to a toy and specifically, to a transforming toy including opposable movable members which pivot toward or away from each other to reveal or conceal a figurine. In one embodiment, the transforming toy includes a first movable member and a second movable member. The first movable member has a semi-circular shape and includes the top portion of the figurine. Specifically, the inside surface of the first movable member includes a body, a first revealing member or first revealer positioned adjacent to and movably connected to the top of the body and a pair of second revealers movably connected to each side of the body. In one embodiment, the first revealer is configured to be a head having a face and the second revealers are each configured to be arms. In one embodiment, the second movable member has a semi-circular shape and includes the lower portion of the figurine. The size and shape of the second movable member corresponds to the size and shape of the first movable member. The second movable member includes a support and a third revealing member or third revealer movably connected to the support. In this embodiment, the support is configured to be a pair of legs and the third revealer is configured to be a pair of feet. In one embodiment, the first and second movable members are each movably connected to a coupler or hinge positioned between the first and second movable members. The first movable member is connected to one end of the coupler. The second movable member is movably connected to a different or opposite end of the coupler. The coupler is adapted to enable the first and second movable members to independently move toward each other until the first and second members are substantially adjacent to each other or in a closed position. The coupler is also adapted to enable the first and second movable members to move away from each other until the first and second movable members are in a substantially open position. The transforming toy of the present invention enables children to move the first and second movable members toward or away from each other to reveal or conceal the figurine connected to the inside surface of the first and second movable members. When the transforming toy is in the closed position, the transforming toy may be rolled, thrown or bounced like a toy ball. To convert or transform the toy into a figurine, a user opens or separates the first and second movable members and moves the first and second movable members away from each other. The user then moves or rotates the first revealer or head to reveal the head having the face. The user then moves or rotates the second revealers or arms away from the body to reveal the arms of the figurine. Next, the user moves or rotates the third movable member or feet of the figurine downwardly away from the support to a substantially perpendicular or transverse position with respect to the support. In the open position, a user such as a child can use the transforming toy as a movable figurine, decorative display or according to any other suitable function. Although in the above embodiment, the transforming toy includes a figurine which may be revealed or concealed inside the toy, it should be appreciated that the transforming toy may include any suitable figurine, character, shape, image or configuration. In another embodiment, the first and second movable members have generally square shape and move toward each other to form a cube in the substantially closed position. It should be appreciated that the first and second movable members can be any suitable size or shape. It is therefore an advantage of the present invention to provide a transformable toy which transforms into different toys. It is another advantage of the present invention to provide a transformable toy that transforms into different toys having different functions. Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged perspective view of one embodiment of the transformable toy of the present invention illustrating the transformable toy in an open position. FIG. 2 is a rear view of the embodiment of FIG. 1. FIG. 3 is an enlarged perspective view of the embodiment of FIG. 1 illustrating the movement of the different revealers. FIG. 4 is an enlarged perspective view of the embodiment of FIG. 1 illustrating the transformable toy in a closed position. FIG. 5 is an enlarged perspective view of another embodiment of the transformable toy of the present invention. DETAILED DESCRIPTION OF THE INVENTION The present invention generally refers to a toy and specifically, to a transformable toy adapted to open and close to reveal and conceal a figurine. Referring now to FIGS. 1 to 4, in one embodiment, a transformable toy 10 includes a first movable member 12, a second movable member 14 and a coupler or hinge 20 connected between the first movable member and the second movable member. In one embodiment, the first movable member and the second movable member have corresponding semi-circular shapes. The first movable member is movably connected to one end of the coupler 20 and moves, pivots or rotates about a horizontal axis extending through the end of the coupler. Similarly, the second movable member 14 is movably connected to an opposite end of the coupler 20 and moves, pivots or rotates about a horizontal axis extending through the opposite end of the coupler. The first movable member 12 and the second movable member 14 are movable towards each other until the first and second movable members are substantially adjacent to each other or in a closed position as illustrated in FIG. 4. The first movable member 12 and the second movable member 14 are also movable away from each other to the open position as illustrated in FIG. 1. In this embodiment, the first movable member 12 and the second movable member 14 have semi-circular shapes and are the same size. It should be appreciated that the first and second movable members may have the same shape, different shapes or any suitable shapes. It should also be appreciated that the first and second movable members may be the same size, different sizes or any suitable size or sizes. In another embodiment, the coupler or hinge is integrally formed with the ends of the first movable member and the second movable member and enables the first and second movable members to pivot or move towards and away from each other as described above. In a further embodiment, the first and second movable members are hingedly connected to enable the first and second movable members to move or pivot towards and away from each other. In one embodiment, a display member 13 is connected to an inside surface of at least one of the first and second movable members 12 and 14, respectively. In this embodiment, the display member 13 is a figure or figurine. It should be appreciated that the display member may be a figure, object, character, image, animal, shape or any other suitable configuration or object. In this embodiment, the display member 13 is a figure or figurine and includes a first revealer 16 formed as a head of the figure, a body 18 positioned adjacent to the first revealer 16, a pair of second revealers 24 in the form of arms movably connected to opposing sides of the body 18, a coupler 20 connected between the first and second movable members, a support 22 positioned adjacent to the coupler and a third revealer 26 positioned adjacent to the support 22 and movably connected to the second movable member. In another embodiment, the coupler 20 is attached to the outside surfaces of the first and second movable members. Therefore in this embodiment, the display member 13 does not include the coupler as part of the figure or object connected to the inside surfaces of the first and second movable members. In one embodiment, the first movable member 12 has a semi-circular shape with a hollow interior portion as illustrated in FIG. 1. A body member or body 18 is connected to an inside surface of the first movable member 12. In one embodiment, the body 18 is a separate part fixedly connected to the inside surface of the first movable member using a suitable adhesive or other suitable attachment method. In another embodiment, the body 18 is integrally formed with the inside surface of the first movable member. In one embodiment, a first revealing member or first revealer 16 is positioned adjacent to the top of the body 18 and movably connected to the first movable member 12. The first revealer includes a pivot member or pivot pin 17 which extends from each side of the first revealer 16. Each end of the pivot pin 17 is movably connected to the first movable member 12. In one embodiment, the pivot pin is a separate component that is attached to the first revealer. In another embodiment, the pivot pin 17 is integrally formed with the first revealer. The pivot pin 17 is adapted to enable the first revealer to move, pivot or rotate about a horizontal axis extending generally though one end of the first movable member 12. Specifically, the first revealer 16 is movable or rotatable from a concealed position shown in FIG. 3 to a revealed or exposed position shown in FIG. 1. It should be appreciated that the first revealer 16 may be moved from the concealed position to the revealed position or from the revealed position to the concealed position. In one embodiment, the first revealer includes at least one surface having an image such as a face as shown in FIG. 1. The image or face is concealed or hidden when the first revealer is in the concealed position as shown in FIG. 3. The face is then revealed, exposed or viewable when the first revealer is moved to the revealed position as shown in FIG. 1. It should be appreciated that the each transformable toy 10 may include the same image or face, at least one different image or face or a plurality of different images or faces. It should also be appreciated that one or more surfaces of the first revealer 16 may include an image such as a face. In one embodiment, at least one second revealing member or second revealer and preferably two second revealers 24 are movably connected to the body 18. In the illustrated embodiment, the second revealers 24 are formed as arms of the figurine. It should be appreciated that the second revealers 24 may be any suitable size or shape. The second revealers 24 are movably or rotatably connected to opposing sides of the body 18. It should be appreciated that the second revealers may be connected to any suitable side of the body. A connector such as a pivot pin (not shown) is connected to each of the second revealers 24 and the body 18 to enable the second revealers to move or rotate relative to the body. The second revealers 24 move from a retracted position as shown in FIG. 3 to a extended or un-retracted position as shown in FIG. 1. It should be appreciated that the second revealers may move from the retracted position to the extended position and from the extended position to the retracted position. The body 18, the first revealer 16 (i.e., the head of the figurine) and the second revealers 24 (i.e., the arms of the figurine) cooperate or co-act to form the upper portion of the figurine connected to the inside surface of the first movable member 12. In one embodiment, the second movable member 14 has a semi-circular shape with a hollow interior portion as illustrated in FIG. 1. A support member or support 22 is connected to an inside surface of the second movable member 14. In one embodiment, the support 22 is a separate part or component fixedly connected to the inside surface of the first movable member using a suitable adhesive or other suitable attachment method. In another embodiment, the support 22 is integrally formed with the inside surface of the second movable member. In one embodiment, a third revealing member or third revealer 26 is positioned adjacent to the bottom of the support 22 and is movably connected to the second movable member 14. The third revealer includes a pivot member or pivot pin 27 which extends from each side of the third revealer 26. Each end of the pivot pin 27 is movably connected to the second movable member 14. In one embodiment, the pivot pin 27 is a separate component that is attached to the third revealer. In another embodiment, the pivot pin 27 is integrally formed with the third revealer. The pivot pin 27 is adapted to enable the third revealer to move, pivot or rotate about a horizontal axis extending generally though one end of the second movable member 14. Specifically, the third revealer 26 is movable or rotatable from a concealed position shown in FIG. 3 to a revealed, exposed or non-concealed position shown in FIG. 1. It should be appreciated that the third revealer 26 may be moved from the concealed position to the revealed position or from the revealed position to the concealed position. In one embodiment, the third revealer 26 includes at least one surface having an image such as the feet shown in FIG. 1. The third revealer 26 (i.e., the feet of the figurine) is concealed or hidden when the third revealer is in the concealed position as shown in FIG. 3. The feet are then revealed, exposed or viewable when the third revealer is moved, pivoted or rotated away from the support 22 to the revealed position as shown in FIG. 1. Additionally, the third revealer includes a receptacle or concave surface 30 which corresponds to the size and shape of the top surface 28 of the first revealer 16. The top surface 28 of the first revealer 16 fits into the receptacle 30 when the first movable member and the second movable member are moved towards each other to the closed position shown in FIG. 4. The mating engagement of the top surface 28 and the receptacle 30 enable the first and second movable members to close together. The support 22 and the third revealer 26 (i.e., the feet of the figurine) cooperate or co-act to form the lower or bottom portion of the figurine connected to the inside surface of the second movable member 14. Accordingly, the upper portion of the figurine connected to the inside surface of the first movable member 12 and the lower portion of the figurine connected to the inside surface of the second movable member 14 co-act to form the figurine of the transformable toy 10. It should be appreciated that any suitable figure, figurine, configuration, character or any other suitable object may be formed or connected to the inside surfaces of the first and second movable members. In one embodiment, the toy 10 includes a locking member or lock (not shown). The lock is connected to at least one of the first and second movable members and is adapted to releasably secure the first and second movable members together when the first and second movable members are in the closed position. It should be appreciated that any suitable lock, latch or securing member may be attached to the first and/or the second movable member. Referring to FIG. 5, another embodiment of the present invention is illustrated where the transformable toy 100 includes a first movable member 102 and a second movable member 104 which each have a cube or generally square shape. In this embodiment, a first revealer 106 is rotatably attached to the first movable member 102 and positioned adjacent to the body 108. The toy also includes a pair of second revealers 114 formed as arms. A coupler 110 is rotatably connected to one end of each of the first second and second movable members 102 and 104, respectively. A support 112 in the formed as a pair of legs is connected to the inside surface of the second movable member 104. A third revealer 116 formed as feet is rotatably connected to the second movable member 104. It should be appreciated that the first movable member and the second movable member may be any suitable shape or configuration and have any suitable size. Operation Referring now to FIGS. 1 to 4, in one embodiment, the transformable toy 10 generally opens and closes to reveal or conceal an object such as a figurine attached to the inside surfaces of the toy. Initially, the first movable member 12 and the second movable member 14 of the toy are moved or pivoted towards each other about the coupler 20 to a closed position as shown in FIG. 4. In the closed position, the toy 10 forms a sphere or ball that can be rolled, bounced, thrown or spun. In this manner, the toy 10 can be used to play marbles or any other suitable game. To open the transformable toy 10 to reveal the figurine inside the toy, a user separates the first and second movable members 12 and 14 respectively and pulls or pushes the first and second movable members apart. The user moves or pivots the first and second movable members apart about the coupler 20 until the first and second movable members are substantially apart or in the open position shown in FIG. 1. In the open position, the first movable member 12 is positioned adjacent to and above the second movable member 14 where the inside surfaces of the first and second movable members are facing or pointing in the same general direction as illustrated in FIG. 1. When the transformable toy 10 is in the open position, the user moves or rotates the first revealer or head 16 of the figurine upwardly away from the inside surface of the first movable member 12. The head is moved or rotated upwardly until the face included on one surface of the head is facing outward from the head or substantially viewable as shown in FIG. 1. The user then moves or rotates one or more of the second revealers or arms 24 outwardly from the inside surface of the first movable member 12 to the extended position shown in FIG. 1. The arms 24 may be independently moved upwardly or downwardly relative to the body 18 to any suitable position or positions. The user then moves or rotates the third revealer or feet portion of the figurine 26 downwardly away from the support 22 until the bottom surface of the feet portion is transverse or perpendicular with the inside surface of the second movable member 14. The bottom surface of the feet portion 26 is substantially planar or flat to enable the toy 10 to stand upright on a flat surface such as a tabletop. After all of the revealing members or revealers are revealed or moved from the concealed position, the toy 10 can be used as a movable figure or figurine such as an action figure or other suitable character. To return the toy 10 back to a closed position, the user moves or pivots the feet 26 upwardly towards the support 22, moves or pivots the arms inwardly towards the inside surface of the first movable member 12 and moves or pivots the head 16 downwardly and towards the inside surface of the first movable member as generally shown by the arrows in FIG. 3. Specifically, the feet 26 pivot to reveal a rounded surface which corresponds to the rounded outside surface of the second movable member 14 as shown in FIG. 4. Additionally, the receptacle 30 is positioned to engage the top surface 28 of the head 16. The arms 24 are pivoted inward and fit into corresponding open spaces or receptacle areas 29 defined by the second movable member 14 to enable the first and second movable members to close together. The head 16 moves or pivots to conceal the face and to align the rounded outside surface of the head 16 with the rounded outside surface of the first movable member 12. The user then moves or pivots the first and second movable members towards each other about the coupler 20 until the first and second movable members are substantially adjacent to each other in the closed position as shown in FIG. 4. The transformable toy 10 of the present invention therefore provides excitement and enjoyment for users such as children because the toy 10 may be pivoted to a closed position and used as a ball. Also, the toy 10 may be opened to reveal a figure or figurine which can stand upright and used as an action figure or as a decorative display. It should be appreciated that the figurine may be any suitable figurine and have any suitable size, image, faces or shape. Additionally, the shape and size of the individual components, such as the movable members, the revealers, the body, the support or any other suitable components may be any suitable size, shape or configuration. It should be appreciated that although the toy described above includes one or more revealing members or revealers, the toy may include no revealers (i.e., the figure or other object is formed on the inside surfaces of at least one of the first and second movable members), one revealer or a plurality of revealers. It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Toys provide excitement and enjoyment for children. Toys come in several different sizes, shapes, configurations and perform many different functions. Some toys have a limited number of functions. Toys with a limited number of functions or uses tend to quickly lose childrens' interest. Accordingly, there is need for toys with multiple functions and different uses to enhance childrens' excitement, enjoyment and interest with the toys. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention generally refers to a toy and specifically, to a transforming toy including opposable movable members which pivot toward or away from each other to reveal or conceal a figurine. In one embodiment, the transforming toy includes a first movable member and a second movable member. The first movable member has a semi-circular shape and includes the top portion of the figurine. Specifically, the inside surface of the first movable member includes a body, a first revealing member or first revealer positioned adjacent to and movably connected to the top of the body and a pair of second revealers movably connected to each side of the body. In one embodiment, the first revealer is configured to be a head having a face and the second revealers are each configured to be arms. In one embodiment, the second movable member has a semi-circular shape and includes the lower portion of the figurine. The size and shape of the second movable member corresponds to the size and shape of the first movable member. The second movable member includes a support and a third revealing member or third revealer movably connected to the support. In this embodiment, the support is configured to be a pair of legs and the third revealer is configured to be a pair of feet. In one embodiment, the first and second movable members are each movably connected to a coupler or hinge positioned between the first and second movable members. The first movable member is connected to one end of the coupler. The second movable member is movably connected to a different or opposite end of the coupler. The coupler is adapted to enable the first and second movable members to independently move toward each other until the first and second members are substantially adjacent to each other or in a closed position. The coupler is also adapted to enable the first and second movable members to move away from each other until the first and second movable members are in a substantially open position. The transforming toy of the present invention enables children to move the first and second movable members toward or away from each other to reveal or conceal the figurine connected to the inside surface of the first and second movable members. When the transforming toy is in the closed position, the transforming toy may be rolled, thrown or bounced like a toy ball. To convert or transform the toy into a figurine, a user opens or separates the first and second movable members and moves the first and second movable members away from each other. The user then moves or rotates the first revealer or head to reveal the head having the face. The user then moves or rotates the second revealers or arms away from the body to reveal the arms of the figurine. Next, the user moves or rotates the third movable member or feet of the figurine downwardly away from the support to a substantially perpendicular or transverse position with respect to the support. In the open position, a user such as a child can use the transforming toy as a movable figurine, decorative display or according to any other suitable function. Although in the above embodiment, the transforming toy includes a figurine which may be revealed or concealed inside the toy, it should be appreciated that the transforming toy may include any suitable figurine, character, shape, image or configuration. In another embodiment, the first and second movable members have generally square shape and move toward each other to form a cube in the substantially closed position. It should be appreciated that the first and second movable members can be any suitable size or shape. It is therefore an advantage of the present invention to provide a transformable toy which transforms into different toys. It is another advantage of the present invention to provide a transformable toy that transforms into different toys having different functions. Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures. | 20040712 | 20071211 | 20060112 | 63514.0 | A63H300 | 1 | RICCI, JOHN A | TRANSFORMABLE TOY | UNDISCOUNTED | 0 | ACCEPTED | A63H | 2,004 |
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10,889,551 | ACCEPTED | Method and apparatus for testing loop pathway integrity in a fibre channel arbitrated loop | A method for performing a fibre channel arbitrated loop integrity test using a fibre channel switch element is provided. The method includes, sending a fibre channel frame through the arbitrated loop; receiving the fibre channel frame after it has traversed through the arbitrated loop; performing a data compare between the fibre channel frame that was sent and the fibre channel frame that is received; detecting internal errors, if any, in the traversed fibre channel loop; and isolating a module that may have generated the error. The switch element includes, a cascade port that is used to couple one fibre channel switch element to another in a loop; and a port that sends a fibre channel frame through the loop and detects internal errors based on the comparison and a isolates a module that may have generated the internal error. | 1. A method for performing a fibre channel arbitrated loop integrity test using a fibre channel switch element, comprising: sending a fibre channel frame through the arbitrated loop; receiving the fibre channel frame after it has traversed through the arbitrated loop; performing a data compare between the fibre channel frame that was sent and the fibre channel frame that is received; detecting internal errors, if any, in the traversed fibre channel loop; and isolating a module that may have generated the error. 2. The method of claim 1, detecting inter connection data path errors between fibre channel switch elements, if the frame is received without any internal errors. 3. The method of claim 1, wherein the internal errors are checked in a transmission protocol engine port of the fibre channel switch elements. 4. The method of claim 1, wherein plural fibre channel switch elements are coupled to each other using a cascade port and the fibre channel frame is allowed to traverse through the plural fibre channel switch element. 5. A fibre channel switch element coupled to an arbitrated loop, comprising: a cascade port that is used to couple one fibre channel switch element to another in a loop; and a port that sends a fibre channel frame through the loop and a compares the fibre channel frame that was sent and the fibre channel frame that is received; and detects internal errors based on the comparison and a isolates a module that may have generated the internal error. 6. The fibre channel switch element of claim 5, detects inter-connection data path errors between fibre channel switch elements, if the frame is received without any internal errors. 7. A system for performing integrity tests in a fibre channel arbitrated loop, comprising: a fibre channel switch element including a host port, a cascade port, a generic port for performing diagnostic services, wherein plural fibre channel switch elements are cascaded in a loop and the generic port sends a fibre channel frame through the loop and a compares the fibre channel frame that was sent and the fibre channel frame that is received; and detects internal errors based on the comparison and a isolates a module that may have generated the internal error. 8. The system of claim 7, wherein the fibre channel switch element detects inter-connection data path errors between fibre channel switch elements, if the frame is received without any internal errors. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 USC Section 119(e), to the following provisional patent applications: Ser. No. 60/487,876 filed on Jul. 16, 2003; Ser. No. 60/487,887 filed on Jul. 16, 2003; Ser. No. 60/487,875 filed on Jul. 16, 2003; Ser. No. 60/490,747 filed on Jul. 29, 2003; Ser. No. 60/487,667 filed on Jul. 16, 2003; Ser. No. 60/487,665 filed on Jul. 16, 2003; Ser. No. 60/492,346 filed on Aug. 04, 2003; and Ser. No. 60/487,873 filed on Jul. 16, 2003. The disclosures of the foregoing applications are incorporated herein by reference in their entirety. BACKGROUND 1. Field of the Invention The present invention relates to networks, and more particularly to performing loop pathway integrity checks in a fibre channel arbitrated loop topology. 2. Background of the Invention Fibre channel is a set of American National Standard Institute (ANSI) standards, which provide a serial transmission protocol for storage and network protocols such as HIPPI, SCSI, IP, ATM and others. Fibre channel provides an input/output interface to meet the requirements of both channel and network users. Fibre channel supports three different topologies: point-to-point, arbitrated loop and fibre channel fabric. The point-to-point topology attaches two devices directly. The arbitrated loop topology attaches devices in a loop. The fibre channel fabric topology attaches host systems directly to a fabric, which are then connected to multiple devices. The fibre channel fabric topology allows several media types to be interconnected. Fibre channel is a closed system that relies on multiple ports to exchange information on attributes and characteristics to determine if the ports can operate together. If the ports can work together, they define the criteria under which they communicate. In fibre channel, a path is established between two nodes where the path's primary task is to transport data from one point to another at high speed with low latency, performing only simple error detection in hardware. FC-AL is one fibre channel standard (incorporated herein by reference in its entirety) that establishes the protocols for an arbitrated loop topology. In a conventional FC-AL implementation there can be as many as 128 ports on the FC-AL loop. The data path consists of several transmit and receive paths. During normal loop operation when Fibre Channel devices are connected, internal data path error, external data path error or interconnection error can cause a failure. Conventional systems do not have testing methods that isolate internal failure from an external failure or interconnection failure. A device causing a failure cannot be isolated using parity checking alone, other more robust testing methods like a CRC check are needed Conventional fabric elements in a FC-AL topology are not robust and do not provide an efficient way to identify, isolate and manage loop traffic. One such problem is shown in system 210 of FIG. 2B. System 210 includes a fibre channel element (or a switch) 216 that couples host systems 213-215 to storage systems 217 and 218. Storage system 217 and 218 include redundant array of independent disks (RAID) 211 coupled via plural input/output (“I/O”) modules and RAID controllers 201A and 201B. If drive 219 is defective, it may disrupt all traffic in common-access network 220. This can result in loop failure and lower performance of the overall network. Another example is shown in FIG. 2A, where a RAID controller 201 is coupled to two different loops 209A and 208A via links 209 and 208 in a disk array system 200. Each loop has a small computer systems interface (SCSI) enclosure services (“SES”) module 202 and 202A. SES modules 202 and 202A comply with the SES industry standard that is incorporated herein by reference in its entirety. Port bypass controller (“PBC”) modules 203 (and 206) couple plural disks (for example, 204, 202B and 207) and link 205 couples the PBC modules. If drive 202B, which is dual ported, fails then both loops 209A and 208A are disrupted. Again, conventional techniques will require that storage 202A be removed and a bypass command issued to all drives, which takes the entire array off-line. Each device is attached and detached to investigate the reason for a link failure. Then all the drives, except the faulty drive are re-attached and loop activity is restored. This system of trial and error is labor intensive and inefficient. Another drawback in conventional Fibre Channel networks is that loop functional test patterns and automatic test pattern generators (“ATPG”) are used to check individual L13 PORTS. Conventional systems do not provide any tests that can check the entire FC-AL loop integrity. Also, there are no pattern generators that can generate an actual Fibre Channel frame with the correct encoding and disparity, consisting of a SOF, Header, Payload, correct Fibre Channel CRC, and EOF to check individual port integrity. Furthermore, de-bugging is performed on a trial and error basis when any failure occurs. Failures are debugged on a board one port at a time, which is tedious and time consuming and hence commercially undesirable. Therefore, there is a need for a method and system for efficiently detecting FC-AL integrity. SUMMARY OF THE INVENTION A method for performing a fibre channel arbitrated loop integrity test using a fibre channel switch element is provided. The method includes, sending a fibre channel frame through the arbitrated loop; receiving the fibre channel frame after it has traversed through the arbitrated loop; performing a data compare between the fibre channel frame that was sent and the fibre channel frame that is received; detecting internal errors, if any, in the traversed fibre channel loop; and isolating a module that may have generated the error. The method also includes detecting interconnection data path errors between fibre channel switch elements, if the frame is received without any internal errors. The internal errors are checked in a transmission protocol engine port of the fibre channel switch elements. Plural fibre channel switch elements are coupled to each other using a cascade port and the fibre channel frame is allowed to traverse through the plural fibre channel switch element. In yet another aspect of the present invention, a fibre channel switch element coupled to an arbitrated loop is provided. The switch element includes, a cascade port that is used to couple one fibre channel switch element to another in a loop; and a port that sends a fibre channel frame through the loop and compares the fibre channel frame that was sent and the fibre channel frame that is received; and detects internal errors based on the comparison and isolates a module that may have generated the internal error. The switch element detects inter-connection data path errors between fibre channel switch elements, if the frame is received without any internal errors. In yet another aspect of the present invention, a system for performing integrity tests in a fibre channel arbitrated loop is provided. The system includes, a fibre channel switch element including a host port, a cascade port, a generic port for performing diagnostic services, wherein plural fibre channel switch elements are cascaded in a loop and the generic port sends a fibre channel frame through the loop and a compares the fibre channel frame that was sent and the fibre channel frame that is received; and detects internal errors based on the comparison and a isolates a module that may have generated the internal error. This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiments thereof concerning the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing features and other features of the present invention will now be described with reference to the drawings of a preferred embodiment. In the drawings, the same components have the same reference numerals. The illustrated embodiment is intended to illustrate, but not to limit the invention. The drawings include the following Figures: FIG. 1 shows a block diagram of a storage area network; FIGS. 2A/2B and 3 show configurations that use the adaptive aspects of the present invention; FIG. 4 shows a block diagram of a switch element, according to one aspect of the present invention and FIG. 4B shows block diagram of a switch element with an internal loop, according to one aspect of the present invention; FIG. 5A and 5B (jointly referred to as FIG. 5) show a block diagram of a transmission protocol engine, according to one aspect of the present invention; FIGS. 6A and 6B show block diagrams for a diagnostic module and a SES module, according to one aspect of the present invention; FIG. 7 shows a block diagram of plural fibre channel switch elements used to couple plural devices, according to one aspect of the present invention; and FIG. 8 shows a flow diagram of executable process steps for performing a loop integrity check using fibre channel frames, according to one aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Definitions: The following definitions are provided as they are typically (but not exclusively) used in the fibre channel environment, implementing the various adaptive aspects of the present invention. “AL_PA”: Arbitrated loop physical address. “FC-AL”: Fibre channel arbitrated loop process described in FC-AL standard. “Fibre channel ANSI Standard”: The standard describes the physical interface, transmission and signaling protocol of a high performance serial link for support of other high level protocols associated with IPI, SCSI, IP, ATM and others. “FC-1”: Fibre channel transmission protocol, which includes serial encoding, decoding and error control. “FC-2”: Fibre channel signaling protocol that includes frame structure and byte sequences. “FC-3”: Defines a set of fibre channel services that are common across plural ports of a node. “FC-4”: Provides mapping between lower levels of fibre channel, IPI and SCSI command sets, HIPPI data framing, IP and other upper level protocols. “LIP”: Loop initialization protocol primitive. “L-Port”: A port that contains Arbitrated Loop functions associated with the Arbitrated Loop topology. “SES”: SCSI Enclosure Services. “TPE”: Transmission Protocol Engine, a controller that operates at the FC-1 level. To facilitate an understanding of the preferred embodiment, the general architecture and operation of a fibre channel system will be described. The specific architecture and operation of the preferred embodiment will then be described with reference to the general architecture of the fibre channel system. FIG. 1 is a block diagram of a fibre channel system 100 implementing the methods and systems in accordance with the adaptive aspects of the present invention. System 100 includes plural devices that are interconnected. Each device includes one or more ports, classified as node ports (N_Ports), fabric ports (F_Ports), and expansion ports (E_Ports). Node ports may be located in a node device, e.g. server 103, disk array 105 and storage device 104. Fabric ports are located in fabric devices such as switch 101 and 102. Arbitrated loop 106 may be operationally coupled to switch 101 using arbitrated loop ports (FL_Ports). The devices of FIG. 1 are operationally coupled via “links” or “paths”. A path may be established between two N_ports, e.g. between server 103 and storage 104. A packet-switched path may be established using multiple links, e.g. an N-Port in server 103 may establish a path with disk array 105 through switch 102. FIG. 3 shows a block diagram of the top-level architecture for system 300 according to one aspect of the present invention. System 300 includes system 307 (a Fibre Channel element) operationally coupled to an array of storage devices 307A that is coupled to a RAID controller 301. RAID system 301A is coupled to switch 303 that is coupled to various computing systems (304-306). System 308, 309, 310, 311 and 312 coupled to storage devices 308A, 309A, 310A, 311A and 312A, are similar to 307/307A configuration. System 307 (or 308-312) allows faulty disks to be easily segregated. For example, if a drive 313 in string 311A is faulty, then system 311 allows drive 313 to be separated, while normal traffic in arrays 301A and 310A continues. FIG. 4A is a block diagram of an 18-port ASIC FC element 400A (also referred to as system 307) according to one aspect of the present invention. FC element 400A provides various functionality in an FC_AL environment, including without limitation, FC element 400A operates as a loop controller and loop switch using switch matrix 408, in accordance with the FC-AL standard. FC element 307 of the present invention is presently implemented as a single CMOS ASIC, and for this reason the term “FC element” and ASIC are used interchangeably to refer to the preferred embodiments in this specification. Although FIG. 4A shows 18 ports, the present invention is not limited to any particular number of ports. System 400A provides a set of port control functions, status indications, and statistics counters for monitoring the health of the loop and attached devices, diagnosing faults, and recovering from errors. ASIC 400A has 18 ports where 16 ports are shown as numeral 405 while a host port 404 and cascade port 404A are shown separately for convenience only. These ports are generic to common Fibre Channel port types, for example, L_Ports. For illustration purposes only, all ports are drawn on the same side of ASIC 400A in FIG. 4A. However, the ports may be located on any side of ASIC 400A. This does not imply any difference in port or ASIC design. Actual physical layout of the ports will depend on the physical layout of the ASIC. Each port has transmit and receive connections to switch matrix 408 and includes transmit protocol engine 407 and a serial/deserializer 406. Frames enter/leave the link 405A and SERDES 406 converts data into 10-bit parallel data to fibre channel characters. Switch matrix 408 dynamically establishes a connection for loop traffic. Switch matrix 408 includes a global arbiter (hence switch matrix 408 is also referred to as SGA 408) that provides lower latency and improved diagnostic capabilities while maintaining full Fibre Channel Arbitrated Loop (FC-AL) compliance. Switch matrix 408 provides a quasi-direct architecture in the form of a buffer-less Switch Matrix. Switch matrix 408 includes data multiplexers that provide a path to each port. In one aspect, twenty multiplexers may be used. In one aspect, data is 16 bits wide plus the internal “K” control signal and two parity bits. At power-up, SGA 408 is setup in a flow-through configuration, which means all ports send what was received on host port 404. When a valid LIP sequence occurs, SGA 408 configures the switch to a complete loop configuration for the address selection process. During normal data transfer on the loop, SGA 408 reconfigures the switch data-path to connect the active ports in what appears as a smaller loop, which lowers the latency but still emulates FC-AL functionality to all entities on the loop. During loop configuration, SGA 408 configures the switch data-path to include a snooping port that walks through each port during the LIP physical address assignment to track each port's assigned arbitrated loop physical address (AL_PA). This snooping process is called the ‘LIP walk’. When the LIP process is done, the firmware records the “port to AL_PA” map in an internal table built in SGA 408. During normal data transfer mode, SGA 408 monitors arbitration requests, open requests, and close primitives to determine which ports have traffic that must be forwarded. The ports that have traffic for the loop provide the necessary information to create the connection points for the switch data-path. The inactive ports are provided the primitive ARB(F0). SGA 408 creates a direct loop connection between source and destination devices. This connection methodology avoids the delay associated with data having to pass from one disk drive member of the loop to the next until the data has completed traversing the loop. System 400A includes plural I2C (I2C standard compliant) interfaces 412-413 that allow system 307 to couple to plural I2C ports each having a master and slave capability. Timer module 411 is provided for controlling timer operations. System 400A also includes a general-purpose input/output interface (“GPIO”) 415. This allows information from system 307 to be analyzed by any device that can use GPIO 415. Control/Status information 419 can be sent or received through module 415. System 400A also includes a SPI module 414 that is used for parallel to serial and serial to parallel transfer between processor 400 firmware and flash memory 421 in the standard Little Endian format. System 400A also includes a Universal Asynchronous Receiver/Transmitter (“UART”) interface 418 that converts serial data to parallel data (for example, from a peripheral device modem or data set) and vice-versa (data received from processor 400) complying industry standard requirements. System 400A can also process tachometer inputs (received from a fan, not shown) using module 417. Processor 400 can read the tachometer input via a tachometer rate register and status register (not shown). System 400A provides pulse width modulator (“PWM”) outputs via module 416. Processor 400 can program plural outputs. System 400A also includes two frame manager modules 402 and 403 that are similar in structure. Processor 400 can access runtime code from memory 420 and input/output instructions from read only memory 409. Module 402 (also referred to as the “diag module 402”) is a diagnostic module used to transfer diagnostic information between a FC-AL and the firmware of system 400A. Diag module 402 is functionally coupled to storage media (via ports 405) via dedicated paths outside switch matrix 408 so that its connection does not disrupt the overall loop. Diag module 402 is used for AL_PA capture during LIP propagation, drive(s) (coupled to ports 405) diagnostics and frame capture. Module 403 (also referred to as “SES module 403”) complies with the SES standard and is functionally coupled to host port 404 and its output is routed through switch matrix 408. SES module 403 is used for in-band management services using the standard SES protocol. When not bypassed, modules 402 and 403 receive primitives, primitive sequences, and frames. Based on the received traffic and the requests from firmware, modules 402 and 403 maintain loop port state machine (LPSM) (615, FIG. 6B) in the correct state per the FC-AL standard specification, and also maintain the current fill word. Based on a current LPSM 615 state (OPEN or OPENED State), modules 402 and 403 receive frames, pass the frame onto a buffer, and alert firmware that a frame has been received. Module 402 and 403 follow FC-AL buffer to buffer credit requirements. Firmware may request modules 402 and 403 to automatically append SOF and EOF to the outgoing frame, and to automatically calculate the outgoing frame's CRC using CRC generator 612. Modules 402 and 403 can receive any class of frames and firmware may request to send either fibre channel Class 2 or Class 3 frames. Port Management Interface (PMIF) 401 allows processor 400 access to various port level registers, SerDes modules 406 and TPE Management Interfaces 509 (FIG. 5). PMIF 401 contains a set of global control and status registers, receive and transmit test buffers, and three Serial Control Interface (SCIF) controllers (not shown) for accessing SerDes 406 registers. FIG. 6A and 6B show block diagrams for module 402 and 403. It is noteworthy that the structure in FIGS. 6A and 6B can be used for both modules 402 and 403. FIG. 6B is the internal data path of a FC port 601 coupled to modules 402/403. Modules 402 and 403 interface with processor 400 via an interface 606. Incoming frames to modules 402 and 403 are received from port 601 (which could be any of the ports 404, 404A and 405) and stored in frame buffer 607. Outgoing frames are also stored in frame buffer 607. Modules 402 and 403 have a receive side memory buffer based on “first-in, first-out” principle, (“FIFO”) RX_FIFO 603 and transmit side FIFO TX_FIFO 604 interfacing with random access FIFO 605. A receive side FIFO 603 signals to firmware when incoming frame(s) are received. A transmit side FIFO 604 signals to hardware when outgoing frames(s) are ready for transmission. A frame buffer 607 is used to stage outgoing frames and to store incoming frames. Modules 602 and 602A are used to manage frame traffic from port 601 to buffers 603 and 604, respectively. Modules 402 and 403 use various general-purpose registers 608 for managing control, status and timing information. Based on the AL_PA, modules 402 and 403 monitor received frames and if a frame is received for a particular module (402 or 403), it will pass the frame onto a receive buffer and alert the firmware that a frame has been received via a receive side FIFO 603. Modules 402 and 403 follow the FC-AL buffer-to-buffer credit requirements using module 616. Modules 402 and 403 transmit primitives and frames based on FC-AL rules. On request, modules 402 and 403 may automatically generate SOF and EOF during frame transmission (using module 613). On request, modules 402 and 403 may also automatically calculate the Cyclic Redundancy Code (CRC) during frame transmission, using module 612. Overall transmission control is performed by module 611 that receives data, SOF, EOF and CRC. A word assembler module 609 is used to assemble incoming words, and a fill word module 610 receives data “words” before sending it to module 611 for transmission. Transmit buffer control is performed by module 614. FIG. 5 shows a block diagram of the transmission protocol engine (“TPE”) 407. TPE 407 maintains plural counters/registers to interact with drives coupled to ports 405. Each TPE 407 interacts with processor 400 via port manager interface 401. Each Fibre Channel port of system 400A includes a TPE module for interfacing to with SerDes 406. TPE 407 handles most of the FC-1 layer (transmission protocol) functions, including 10B receive character alignment, 8B/10B encode/decode, 32-bit receive word synchronization, and elasticity buffer management for word re-timing and TX/RX frequency compensation. SerDes modules 406 handle the FC-1 serialization and de-serialization functions. Each SerDes 406 port consists of an independent transmit and receive node. SerDes 406 and TPE 407 are capable of operating at both 1 (1.0625) and 2 (2.125) Gbaud with transmit and receive sections under independent frequency control to facilitate link speed negotiation. TPE 407 has a receive module 500 (that operates in the Rx clock domain 503) and a transmit module 501. Data 502 is received from SERDES 406 and decoded by decoding module 504. A parity generator module 505 generates parity data. SGA interface 508 allows TPE to communicate with switch 514 or switch matrix 408. Interface 508 (via multiplexer 507) receives information from a receiver module 506 that receives decoded data from decode module 504 and parity data from module 505. Management interfaces module 509 interfaces with processor 400. Transmit module 501 includes a parity checker 511, a transmitter 510 and an encoder 512 that encodes 8-bit data into 10-bit data. 10-bit transmit data is sent to SERDES 406 via multiplexer 513. Port Management Interface (PMIF) 401 allows processor 400 access to various port level registers, SerDes modules 406 and TPE Management Interfaces 509 (MIFs). PMIF 401 contains a set of global control and status registers, receive and transmit test buffers, and three Serial Control Interface (SCIF) controllers (not shown) for accessing SerDes 406 registers. In one aspect of the present invention, FC-AL integrity checks can be performed for internal and external data paths. L_PORTS are connected inside a switch from a receive path of one port to a transmit path of the next port. Each port has an internal loop back inside the SERDES (406A, as shown in FIG. 4B). FIG. 4B also show host port 404 coupled to SGA 408 and via path 408A is coupled to cascade port 404A. Internal switch connection is shown as 407B and the receive path is shown as 407A. Connecting the last cascade port to a first system 307 completes the loop. Host and Cascade ports are used to make external connections between plural systems 307, as shown in FIG. 7. In FIG. 7, system 700 includes plural system 307 (shown as 307-1 to 307-N). A host bus adapter “HBA” (“701”) is also shown that is located in the storage sub-system or a host and is coupled to TPE 407. Cascade ports 404A and host ports 404 allow plural systems 307 to be operationally coupled. In one aspect of the present invention, the loop integrity test is implemented by transmitting a known Fibre Channel frame from one TPE port to the next TPE port. The frame traverses the transmit path inside the TPE port where a Parity Detector checks for any Parity errors and a CRC checker checks for CRC errors on the Receive path. The Frame then loops back from the Transmit path to the receive path which then goes to the next TPE port transmit path through the switch. This process takes place in all the TPE ports until the frame traverses the loop. SES 403 receives the frame back from the Host port 404 TPE after the frame has passed through all the TPE ports. A data comparison of the frame Payload and Header determines the result of the test. Parity errors and/or CRC errors detected inside a particular TPE port can be used to isolate that port. If Parity errors and/or CRC errors are not detected in any of the ports, then the error may be caused due to a faulty interconnection between systems 307 (See FIG. 7). In this case, the test can be repeated by removing system 307 one at a time and performing the test until the test fails. In one aspect of the present invention, the foregoing test can also be used to detect failures caused by external faulty paths, like the path between a Fibre Channel Device and a SERDES. By including the port that is causing errors, integrity tests are also performed. A failure of the test routine will indicate an internal or external data path error. FIG. 8 shows a flow diagram of executable process steps for performing a loop integrity check using fibre channel frames, according to one aspect of the present invention. The process starts in step S800. In step S801, SES 403 sends a fibre channel frame to the FC-AL and the frame traverses the loop. In step S802, SES 403 receives the traversed frame from host port 404 and data compare is performed in step S803. If the data compare passes, then the loop integrity test is deemed successful in step S804. If the data compare fails in step S803, then in step S805 the process checks for internal errors in TPE ports. If no parity errors and/or CRC errors are detected in the TPE ports then in step S807, the process determines interconnection errors between plural systems 307. Each individual system 307 is isolated in step S808 and interconnection errors are detected. Thereafter, the process reverts back to step S801. If parity/CRC errors are detected in step S805, then in step s806, the defective TPE port is isolated from switch matrix 408 and the process returns to step S801. In one aspect of the present invention, an actual fibre channel frame is used to perform the integrity check, rather than a random test pattern. Although the present invention has been described with reference to specific embodiments, these embodiments are illustrative only and not limiting. Many other applications and embodiments of the present invention will be apparent in light of this disclosure and the following claims. | <SOH> BACKGROUND <EOH>1. Field of the Invention The present invention relates to networks, and more particularly to performing loop pathway integrity checks in a fibre channel arbitrated loop topology. 2. Background of the Invention Fibre channel is a set of American National Standard Institute (ANSI) standards, which provide a serial transmission protocol for storage and network protocols such as HIPPI, SCSI, IP, ATM and others. Fibre channel provides an input/output interface to meet the requirements of both channel and network users. Fibre channel supports three different topologies: point-to-point, arbitrated loop and fibre channel fabric. The point-to-point topology attaches two devices directly. The arbitrated loop topology attaches devices in a loop. The fibre channel fabric topology attaches host systems directly to a fabric, which are then connected to multiple devices. The fibre channel fabric topology allows several media types to be interconnected. Fibre channel is a closed system that relies on multiple ports to exchange information on attributes and characteristics to determine if the ports can operate together. If the ports can work together, they define the criteria under which they communicate. In fibre channel, a path is established between two nodes where the path's primary task is to transport data from one point to another at high speed with low latency, performing only simple error detection in hardware. FC-AL is one fibre channel standard (incorporated herein by reference in its entirety) that establishes the protocols for an arbitrated loop topology. In a conventional FC-AL implementation there can be as many as 128 ports on the FC-AL loop. The data path consists of several transmit and receive paths. During normal loop operation when Fibre Channel devices are connected, internal data path error, external data path error or interconnection error can cause a failure. Conventional systems do not have testing methods that isolate internal failure from an external failure or interconnection failure. A device causing a failure cannot be isolated using parity checking alone, other more robust testing methods like a CRC check are needed Conventional fabric elements in a FC-AL topology are not robust and do not provide an efficient way to identify, isolate and manage loop traffic. One such problem is shown in system 210 of FIG. 2B . System 210 includes a fibre channel element (or a switch) 216 that couples host systems 213 - 215 to storage systems 217 and 218 . Storage system 217 and 218 include redundant array of independent disks (RAID) 211 coupled via plural input/output (“I/O”) modules and RAID controllers 201 A and 201 B. If drive 219 is defective, it may disrupt all traffic in common-access network 220 . This can result in loop failure and lower performance of the overall network. Another example is shown in FIG. 2A , where a RAID controller 201 is coupled to two different loops 209 A and 208 A via links 209 and 208 in a disk array system 200 . Each loop has a small computer systems interface (SCSI) enclosure services (“SES”) module 202 and 202 A. SES modules 202 and 202 A comply with the SES industry standard that is incorporated herein by reference in its entirety. Port bypass controller (“PBC”) modules 203 (and 206 ) couple plural disks (for example, 204 , 202 B and 207 ) and link 205 couples the PBC modules. If drive 202 B, which is dual ported, fails then both loops 209 A and 208 A are disrupted. Again, conventional techniques will require that storage 202 A be removed and a bypass command issued to all drives, which takes the entire array off-line. Each device is attached and detached to investigate the reason for a link failure. Then all the drives, except the faulty drive are re-attached and loop activity is restored. This system of trial and error is labor intensive and inefficient. Another drawback in conventional Fibre Channel networks is that loop functional test patterns and automatic test pattern generators (“ATPG”) are used to check individual L 13 PORTS. Conventional systems do not provide any tests that can check the entire FC-AL loop integrity. Also, there are no pattern generators that can generate an actual Fibre Channel frame with the correct encoding and disparity, consisting of a SOF, Header, Payload, correct Fibre Channel CRC, and EOF to check individual port integrity. Furthermore, de-bugging is performed on a trial and error basis when any failure occurs. Failures are debugged on a board one port at a time, which is tedious and time consuming and hence commercially undesirable. Therefore, there is a need for a method and system for efficiently detecting FC-AL integrity. | <SOH> SUMMARY OF THE INVENTION <EOH>A method for performing a fibre channel arbitrated loop integrity test using a fibre channel switch element is provided. The method includes, sending a fibre channel frame through the arbitrated loop; receiving the fibre channel frame after it has traversed through the arbitrated loop; performing a data compare between the fibre channel frame that was sent and the fibre channel frame that is received; detecting internal errors, if any, in the traversed fibre channel loop; and isolating a module that may have generated the error. The method also includes detecting interconnection data path errors between fibre channel switch elements, if the frame is received without any internal errors. The internal errors are checked in a transmission protocol engine port of the fibre channel switch elements. Plural fibre channel switch elements are coupled to each other using a cascade port and the fibre channel frame is allowed to traverse through the plural fibre channel switch element. In yet another aspect of the present invention, a fibre channel switch element coupled to an arbitrated loop is provided. The switch element includes, a cascade port that is used to couple one fibre channel switch element to another in a loop; and a port that sends a fibre channel frame through the loop and compares the fibre channel frame that was sent and the fibre channel frame that is received; and detects internal errors based on the comparison and isolates a module that may have generated the internal error. The switch element detects inter-connection data path errors between fibre channel switch elements, if the frame is received without any internal errors. In yet another aspect of the present invention, a system for performing integrity tests in a fibre channel arbitrated loop is provided. The system includes, a fibre channel switch element including a host port, a cascade port, a generic port for performing diagnostic services, wherein plural fibre channel switch elements are cascaded in a loop and the generic port sends a fibre channel frame through the loop and a compares the fibre channel frame that was sent and the fibre channel frame that is received; and detects internal errors based on the comparison and a isolates a module that may have generated the internal error. This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiments thereof concerning the attached drawings. | 20040712 | 20080617 | 20050203 | 73234.0 | 0 | WONG, XAVIER S | METHOD AND APPARATUS FOR TESTING LOOP PATHWAY INTEGRITY IN A FIBRE CHANNEL ARBITRATED LOOP | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,889,577 | ACCEPTED | Computer program, method, and system for monitoring nutrition content of consumables and for facilitating menu planning | A computer program, method, and system for dynamically and interactively providing nutrition content information for consumables such that a user may monitor, tailor, plan, and review their intake thereof in light of a health-related interest or concern, such as, for example, weight-loss, food allergies, or diabetes or other nutrition affected illnesses or disabilities. Consumables are categorized and displayed in lists associated with an appropriate color to draw attention to relative nutrition content and to facilitate quicker and easier evaluation of a consumable of interest. Summaries are provided of a user's actual intake in light of a pre-established target intake for a particular day. Detailed reports may be generated showing consumption over a user-specifiable time period. | 1. A computer program comprising a combination of code segments stored in a computer-readable memory and executable by a processor to provide nutrition information, the computer program comprising: a database including consumables and related nutrition content information; a code segment operable to receive an input relating to a health-related concern; a code segment operable to sort the consumables into a plurality of scrollable lists based on the input and the nutrition content information; and a code segment operable to display the lists. 2. The computer program as set forth in claim 1, wherein each of the lists is associated with a color to aid a user in evaluating the relative effect of consumables in the list with regard to the health-related concern. 3. The computer program as set forth in claim 1, further including a code segment operable to receive login information identifying a user, and recalling, based upon the login information, a user data set of specific user information. 4. The computer program as set forth in claim 1, wherein the database is accessible through a computing network. 5. The computer program as set forth in claim 1, further including a code segment operable to customize the database based on a consumption habit. 6. The computer program as set forth in claim 1, wherein the health-related concern is selected from the group consisting of the following: caloric content, protein content, carbohydrate content, fat content, vitamin content, mineral content, sugar content. 7. The computer program as set forth in claim 1, further including a code segment operable to accept a target consumption value corresponding to a maximum future intake of one or more nutrients. 8. The computer program as set forth in claim 7, further including a code segment operable to allow a user to select at least one of the consumables from the lists. 9. The computer program as set forth in claim 8, further including a code segment operable to determine and display a remaining consumption value based on the difference between the target consumption value and the related nutrition content information of each selected consumable. 10. A computer program comprising a combination of code segments stored in a computer-readable memory and executable by a processor to provide nutrition information, the computer program comprising: a database including consumables and related nutrition content information; a code segment operable to receive an input relating to a health-related concern; a code segment operable to sort the consumables into a plurality of scrollable, color-associated lists based on the input and the nutrition content information; a code segment operable to customize the database based on a consumption habit; a code segment operable to allow the user to select at least one of the consumables from the lists; a code segment operable to accept a target consumption value corresponding to a maximum future intake of one or more nutrients; a code segment operable to determine a remaining consumption value based on the difference between the target consumption value and the related nutrition content information of each selected consumable; and a code segment operable to display the lists and the remaining consumption value. 11. The computer program as set forth in claim 10, further including a code segment operable to receive login information identifying a user, and recalling, based upon the login information, a user data set of specific user information. 12. The computer program as set forth in claim 10, wherein the database is accessible through a computing network. 13. The computer program as set forth in claim 10, wherein the health-related concern is selected from the group consisting of the following: caloric content, protein content, carbohydrate content, fat content, vitamin content, mineral content, sugar content. 14. A hand-held apparatus for providing nutrition content information, the hand-held apparatus comprising: a housing; a computer-readable memory located within the housing and storing a combination of code segments and a database including consumables and related nutrition content information; a processor located within the housing and operable to execute the combination of code segments and access the database to sort the consumables into a plurality of lists corresponding to a health-related concern; an output device incorporated into the housing and operable to display an interactive display screen generated by the combination of code segments, the interactive display screen presenting the lists and a remaining consumption value; and an input device coupled with the processor and operable to allow a user to select a particular consumable from the lists and to enter a target consumption value corresponding to a maximum future intake of one or more nutrients, whereupon the processor determines the remaining consumption value based on the difference between the target consumption value and the related nutrition content information of each selected consumable 15. The hand-held apparatus as set forth in claim 14, wherein the health-related concern is selected from the group consisting of the following: caloric content, protein content, carbohydrate content, fat content, vitamin content, mineral content, sugar content. 16. The hand-held apparatus as set forth in claim 14, wherein input device is operable to allow the user to customize the database based on a consumption habit. 17. The hand-held apparatus as set forth in claim 14, wherein the hand-held apparatus is powered exclusively by one or more cells or batteries. 18. The hand-held apparatus as set forth in claim 14, wherein the input device is a stylus. 19. The hand-held apparatus as set forth in claim 14, wherein the input device is a touch screen. 20. The hand-held apparatus as set forth in claim 14, wherein the output device is a liquid crystal display. | RELATED APPLICATION The present application is a continuation and claims priority benefit, with regard to all common subject matter, of earlier-filed U.S. patent application titled “COMPUTER PROGRAM, METHOD, AND SYSTEM FOR MONITORING NUTRITION CONTENT OF CONSUMABLES AND FOR FACILITATING MENU PLANNING”, Ser. No. 09/878,651, filed Jun. 11, 2001. The identified earlier-filed patent application is hereby incorporated into the present application by specific reference. BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates to a computer program, method, or system for providing nutrition content information for consumables. More particularly, the present invention relates to a computer program, method, or method for dynamically and interactively providing nutrition content information for consumables such that a user may monitor, tailor, plan, and review their intake thereof in light of a health-related interest or concern, such as, for example, weight loss, food allergies, or diabetes or other nutrition-affected illnesses or disabilities. 2. DESCRIPTION OF THE PRIOR ART It is often desirable to monitor nutrition content of consumables, including, for example, calories, fat, sugar, protein, or carbohydrates. This is particularly true where such nutrition content may affect a health-related interest or concern, including, for example, weight loss, food allergies, or diabetes or other nutrition-affected illnesses or disabilities. Relatedly, it is further desirable to plan future consumption based upon nutrition content, and to review past consumption summarized for a specifiable time period. Various print resources exist to facilitate monitoring nutrition content. Books, for example, provide long lists of consumables and related nutrition information. Furthermore, most packaged consumables provide nutrition information on the packaging. Unfortunately, print resources suffer from a number of limitations and disadvantages. Books, for example, are bulky and difficult to conveniently tailor for efficient use by any particular person (short of adding or removing pages), which reduces likelihood of consistent use. Package-based information is, of course, limited to packaged foods. Furthermore, print resources are generally unable to practically present nutrition information in a visually descriptive manner operable to conveniently impart to a user a sense of a particular consumable's place in an overall monitoring scheme. Additionally, print resources are generally unable to practically provide a convenient mechanism whereby future consumption can be dynamically planned and past consumption can be reviewed. It is known to use computers and computer programs to facilitate monitoring and planning intake of consumables. Existing programs, however, are typically non-interactive and non-dynamic and therefore inconvenient and awkward to use, which may decrease compliance and effectiveness. Furthermore, existing programs typically do not allow for substantial modification or customization to suit users' particular consumption habits or preferences, which may make the program inapplicable to or unuseable by some people or cultures. Due to the above identified problems and shortcomings in the existing art, an improved computer program or method is needed for monitoring nutrition information of consumables and intake thereof. SUMMARY OF THE INVENTION The present invention provides a computer program, method, and system for dynamically and interactively providing nutrition content information for consumables such that a user may monitor, tailor, plan, and review their intake thereof in light of a health-related interest or concern, such as, for example, weight-loss, food allergies, or diabetes or other nutrition affected illnesses or disabilities. Nutrition content of interest may include, for example, protein, carbohydrates, fat, vitamins, minerals, calories, sugar, etc. Consumables are categorized according to a predetermined scheme of categorization, and the categories are displayed as scrollable and searchable lists. The lists are associated with an appropriate color to draw attention to the categories' relative nutrition content and to facilitate quicker and easier evaluation of a consumable of interest. Furthermore, menus may be planned in advance wherein projected intake of particular consumables is recorded. Additionally, summaries are provided of actual intake in light of a pre-established target intake for a particular day, week, month, or other user-specifiable time period. The lists of consumables and associated nutrition content information are stored in a database customizable with regard to adding or deleting consumables and editing the nutrition content information. Thus, the user is able to adapt the program to more personally reflect their eating habits and preferences. For example, a user who does not eat meat may delete all meat items from the database in order to make finding and selecting non-meat consumables more convenient; and a user who uses low-fat or no-sugar ingredients or who reduces calories by baking rather than frying may edit the nutrition content information to reflect the change. Furthermore, users from different cultures may tailor the database to include consumables specific to that culture. As mentioned, the consumables are categorized according to a predetermined scheme of categorization based upon the user's health-concern or interest. For example, where the user desires to monitor calorie and fat content to facilitate weight loss, the consumables may be divided into three groups—low, medium, and high calorie and fat content—and the groups associated with an appropriately recognizable display color, such as green for low or safe or desirable, yellow for medium or warning, and red for high or dangerous or generally undesirable with regard to the nutrition content of interest, to facilitate the user's recognition and understanding of any particular consumable's effect, relative to other consumables, on the user's goals. Though the computer program and method may be implemented on any computing device, including, for example, a desktop or laptop personal computer, in a preferred embodiment the computer program is stored on and executed by a small, portable, battery-power, dedicated hand-held device. Because the small hand-held device is more conveniently and less conspicuously carried than a conventional desktop of laptop computer, the user is more likely to enter more consumption data at the time of consumption or shortly thereafter, thereby greatly increasing proper and consistent use of the present invention. These and other advantages of the present invention are further described in the section entitled DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT, below. BRIEF DESCRIPTION OF THE DRAWING FIGURES A preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein: FIG. 1 is a block diagram depicting a system or apparatus that may be used to implement a preferred embodiment of the present invention; FIG. 2 is a first screen capture showing a first preferred interface screen generated by a preferred embodiment of a computer program of the present invention; FIG. 3 is a second screen capture showing a second preferred interface screen generated by a preferred embodiment of a computer program of the present invention; FIG. 4 is a third screen capture showing an input window generated by a preferred embodiment of a computer program of the present invention; FIG. 5 is a fourth screen capture showing a help window generated by a preferred embodiment of a computer program of the present invention; and FIG. 6 is a fifth screen capture showing a hint window generated by a preferred embodiment of a computer program of the present invention. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 illustrates a preferred embodiment of a system 10 for dynamically and interactively providing nutrition content information for consumables such that a user may monitor, tailor, plan, and review their intake thereof in light of a health-related interest or concern, such as, for example, weight loss, diabetes or other nutrition affected illnesses, or food allergies. The preferred system 10 broadly comprises a processor 12; an input device 14; an output device 16; a memory 18; and a network connection 20. The system 10 is independent of any specific nature or details of its various components so long as the combination thereof is operable to practice the invention as herein described. Thus, the system 10 may, for example, be a conventional desktop personal computer, a conventional portable laptop or notebook computer, or a conventional networked thin-client terminal. Alternatively, the system 10 may be a portable, exclusively battery-powered, hand-held dedicated device enclosed within a housing 22 and specifically adapted to practicing the present invention. This latter embodiment is advantageous in that the resulting device is smaller and less expensive than the conventional devices previously mentioned, and allows the present invention to be more conveniently carried and practiced, thereby increasing likelihood and frequency of use. The processor 12 may be any suitable conventional processing device operable to receive input from the input device 14, consult a database of consumables and related nutrition content information, and report results via the output device 16. The input device 14 allows the user to provide input to the processor 12. Such input may include login or identification information; target consumption values; and consumables already or prospectively consumed. As mentioned, the exact nature and details of the input device 14 are generally unimportant to the present invention, and may depend greatly upon the nature of the system 10. For example, a general-purpose conventional computer system may provide a variety of suitable input devices, including a keyboard, a computer mouse or trackball, a light pen, or a touch screen. A hand-held dedicated system or apparatus may be more limited in the types of input devices able to be supported, and may be limited to a stylus-type instrument. The output device 16 visually and dynamically communicates information to the user. The output device 16 is preferably a screen of some suitable type, such as, for example, a conventional computer monitor or a liquid crystal display. The memory 18 and network connection 20 are alternative or complimentary mechanisms for storing/accessing the computer program of the present invention. In some embodiments, only the memory 18 is included, it being operable to store the program, including the database of consumables, in its entirety. Any suitable memory 18 may be used, including a hard disk, a floppy disk, a compact disk, or a read only memory chip. In other equally preferred embodiments, only the network connection 20 is included, it being operable to provide access via a communication network 24 (e.g., a local area network, a wide area network, or the Internet) to the program, wherein the program is remotely stored. In still other equally preferred embodiments, both the memory 18 and the network connection 20 are included. In these latter embodiments, a first portion of the program may be stored in the memory 18 and a second portion, possibly the database of consumables, may be accessed via the network connection 20 and communication network 24. The computer program comprises a combination of code segments accessible to and executable by the processor 12 of the above-described system 10, and operable to facilitate monitoring, tailoring, planning, and reviewing intake of consumables based upon nutrition content in light of a health-related interest or concern. The code segments may be written in any programming language, including JAVA or C++, as a matter of design choice, and stored on any suitable computer readable memory media, such as, for example, a hard disk, a floppy disk, a compact disk, or a read only memory chip. The preferred computer program broadly comprises a database (or a code segment to access such) of consumables and related nutrition content information; a code segment operable to generate an interactive display screen for display on the output device 16; a code segment providing for prospective menu planning; and a code segment for generating summaries of past consumption over a user specifiable time period. The database serves as a repository of the nutrition content information, which may be implemented as single large general data repository or a plurality of smaller linked data-specific databases, and, as mentioned above, may be stored in the memory 18 forming a part of the system 10 or may be located in and accessed from one or more remote memory storage devices. Where the database is remotely located, access thereto is preferably accomplished via the communications network 24, such as the Internet. Preferably, the user is able, as desired, to edit information stored in the database, at least with regard to how the database appears to the particular user. Such editing may include, for example, adding or delete consumables, or changing nutrition content information. Thus, the database is customizable to the particular user's consumption habits, allowing the user to adapt the program to more personally reflect their eating habits and preferences. For example, a user who does not eat meat may delete all meat items from the database in order to make finding and selecting non-meat consumables more convenient; and a user who uses low-fat or no-sugar ingredients or who reduces calories by baking rather than frying may edit the nutrition content information to reflect the change. Furthermore, users from different cultures may tailor the database to include consumables specific to that culture. The code segment operable to generate an interactive display screen is also operable to present scrollable or drop-down lists of consumables, wherein the consumables have been categorized according to a predetermined scheme of categorization based upon the particular health-related concern or interest. The lists are displayed associated with a color appropriate to facilitate the user's easy understanding and evaluation of a consumable of interest. For example, where the user desires to monitor calorie and fat content to facilitate weight loss, the consumables may be divided into three groups—low, medium, and high calorie and fat content—and the groups associated with an appropriately recognizable color, such as green for low or safe, yellow for medium or warning, and red for high or dangerous, to facilitate the user's recognition and evaluation of any particular consumable's effect, relative to other consumables, on the user's goals. This particularly advantageous feature places each consumable into a larger context rather than presenting mere sterile information devoid of context. Thus, the present invention's use of color-based presentation allows for a conveniently intuitive evaluation of a consumable of interest. The code segment providing for prospective menu planning allows the user to select a desired date, set a target value representing a maximum threshold intake of one or more nutrients, and plan and store a menu of consumption for the selected day. The code segment for generating historical summaries allows the user to review past consumption and nutrient intake over a user-specifiable time period, such as a day, week, month, or year. This advantageous feature allows the user to review their compliance and progress toward achieving their health-related goal. Referring also to FIG. 2, the Interface Screen 28 provides a visual mechanism facilitating user interaction with the computer program, and comprises a Title Bar 30; a Menu Bar 32; a Lookup Box 34; a plurality of Food Categories 36; a Date Field 38; a Target Section 40; and a Summary Section 42. The Title Bar 30 identifies the computer program and the current user, which is particularly useful where two or more persons use the same instance of the program on the same system 10. The identity information displayed in the Title Bar 30 is provided by the current user who is required to login at the beginning of each session. The login requirement allows the program to record custom parameters selected by the current user during the current session and retrieve any previously select customs parameters; such parameters may include display preferences and edits to the list of consumables and nutrition content. The Menu Bar 32 presents four menu anchors selectable to display drop-down menus of selectable functions. The four menu anchors correspond to a File menu 44; a Menu menu 46; an Options menu 48, and a Help menu 50. The File menu is a drop-down menu presenting a number of selectable functions, including Select Person; Add New Person; Delete Person; Print Report; Preview Report; Printer Setup; and Exit. The Select Person function causes a list of previously registered users to appear from which the current user may select him or herself, thereby making the login process more convenient. The Add New Person function allows the user, if not previously registered,to login for the first time. Thereafter, to login the user may simply select him or herself from the Select Person list. The Delete Person function allows a previously registered user to be deleted such that their name will no longer appear on the Select Person list. The Print Report, Preview Report, and Printer Setup are all conventional functions related to printing reports and summaries of past consumption. The Exit function is conventionally operable to exit the computer program. The Menu 46 is a drop-down menu presenting a number of selectable functions, including Add 1; Remove 1; Delete Item; Revise Item; New Food Item. The Add 1 function causes one instance of a particular consumable, which is highlighted in the scrollable lists, to be added to the intake record. The Remove 1 function causes one instance of a particular consumable, which is highlighted in the scrollable lists, to be removed from the intake record. The Delete Item function causes a highlighted consumable to be deleted from the scrollable lists, thereby making customization of the consumables database or corresponding lists more convenient. The Revise Item and Add New Food Item functions are similar in that each produces an interactive window 60 (see FIG. 4) wherein a consumable's name, nutrition content, and portion size may be edited or added in corresponding data fields, and the consumable may be reassigned to a different grouping or scrollable list. This latter reassignment may be conveniently accomplished using selectable radio buttons 62 corresponding to the various groups or lists. The Revise Item and Add New Item functions are distinguishable in that the Revise Item function applies to consumables already present in the database such that the data fields are initially filled with existing, editable data, whereas, using the Add New Item function, the data fields are blank. The Options menu 48 is a drop-down menu presenting a number of selectable functions, including Counts, Remaining, and Show Hints. The Counts and Remaining functions toggle the display between, respectively, total nutrition content value consumed and percentage of total nutrition content value remaining for consumption relative to the pre-established Target Values (where the Target Values represent 100%). The Show Hints function, when selected, causes a hint window 68 to appear that communicate consumption and nutrition tips (see FIG. 6). The tips are preferably editable so that the user may customize the tips to their own needs. The Help menu 50 is a drop-down menu presenting a number of selectable functions, including Help. The Help function causes a conventional help screen 66 to appear with which the user may learn about the present invention and investigate particular functions (see FIG. 5). The Lookup Box 34 allows a user to quickly find consumables in the lists. In use, a user begins typing the name of the consumable into the Lookup Box 34; as letters are typed, the box 34 actively matches those letters to a drop down menu of similarly named consumables, thereby displaying consumables whose spelling matches the user input. At any point the user may finish entering the consumable's name or select it from the drop down menu. Once entered in the Lookup Box 34, the consumable becomes the active item in the Food Categories 36. The plurality of Food Categories 36 are scrollable lists 52,53,56 of consumables grouped according to one or more predetermined characteristics, such as, for example, nutrition value, calorie values, or fat values. In the illustrated embodiment, for example, consumables are divided into three groups—low, medium, and high calorie and fat content—and the groups are displayed in scrollable lists 52,54,56 wherein each group is associated with an appropriately recognizable color, such as green for low or safe, yellow for medium or warning, and red for high of dangerous, to facilitate the user's recognition and evaluation of any particular consumable's effect, relative to other consumables, on the user's goals. Also in the preferred embodiment, the lists 52,54,56 are labeled Go For It, Be Careful, and Stop. . . Think. The Go For It category 52 presents a columnar scrollable list of selectable consumables which are generally desirable, being, for example, low in calories and fat. Because the color green is generally associated with the concept of safety, the list is preferably highlighted or otherwise indicated in green. The Be Careful category 54 presents a columnar scrollable list of selectable consumables for which caution should be observed, they being higher in calories and fat than those in the previous category. Because the color yellow is generally associated with the concept of caution, the list is preferably highlighted or otherwise indicated in yellow. The Stop . . . Think category 56 presents a columnar scrollable list of selectable consumables for which a great deal of consideration should be given prior to consumption, they being even higher in calories and fat than those in the previous categories and generally undesirable or unsafe with regard to the nutrition content of interest. Because the color red is generally associated with the concept of danger, the list is preferably highlighted or otherwise indicated in red. The Date Field 38 facilitates tracking consumption on a daily basis. The Date Field 38 defaults to the current date when the program is executed, and can thereafter be adjusted to reflect any date the user desires. The Date Field 38, in conjunction with the Summary Section 42 described below, facilitates menu planning over an extended period of time, including days or weeks. The Target Section 40 allows the user to set their own personal daily target values for nutrients, such as grams of fat and calories consumed. The target values provide threshold means for determining whether the user's intake goals have been met. The Summary Section 42 comprises two calenderic tables, a Month table 70 and a Day table 72. The Month Table 70 includes twelve month cells 74, with each month cell 74 corresponding to a particular month of a year. Each month cell 74 contains four items, including the first three letters of the name of the month (e.g., Jan for January); the number of days of that month for which consumption data has been entered; and a fat value and a calorie value displayed in either “Count” or “Remaining” formats. In Count format, the fat and calorie values are displayed as Total Target minus Total Consumed, wherein Total Target is calculated as the daily Target Value multiplied by the number of days for which data has been entered. In Remaining format, the fat and calorie values are similarly calculated though displayed as percentages, wherein Total Target is 100%. In either format, when Total Consumed fat or calories exceeds Total Target, the value is displayed in red to draw attention and indicate a violation of the Target Values. The Summary Section 42 of FIG. 2 illustrates the Count format; the Summary Section 42 of FIG. 3 illustrates the Remaining format. The Day Table 72 includes twenty-eight day cells 76 (four rows of seven columns), with each day cell 76 corresponding to a particular day of a month. Each day cell 76 contains three items, including the month and day, and a fat value and a calorie value displayed in either “Count” or “Remaining” formats. The display formats are substantially similar to those described above. In the Day Table 72, however, Total Target is merely the Target Value, rather than a multiple thereof. Where Total Consumed exceeds Total Target, the values are displayed in red. For example, initially, each month cell 74 in the Month Table 70 reflects no fat consumed and no calories consumed. If the user were to enter a target fat value of 35 and a target calorie value of 1800, each cell 76 in the Day Table 72 would automatically change to reflect these Target Values. Subsequently, as the user enters consumption data for a particular date, the fat and calorie values in that day cell 76 change to reflect the consumption in light of the Target Values. Furthermore, the corresponding month cell 74 will change, as described above, to reflect that data has been entered for a day of that month. The Month and Day Tables 70,72 provide convenient quick summaries of consumption patterns over time. They also facilitate menu planning in that, upon adding an item to the consumption record, the user is immediately shown the effect of the addition on their consumption goal. This is particularly helpful where the addition of a particular item would cause total consumption to exceed Target Values for that time period. With regard to the nature of the input device 14, the Interface Screen 28 can be navigated and operated using a keyboard, mouse, stylus, or other similar input device. Using a keyboard, the menu items can be accessed through the Alt-F(ile), Alt-M(enu), Alt-O(ptions) and Alt-H(elp). Conventional hot key techniques can be used to select drop down menus or particular functions from the drop down menus. The main screen 28 is organized as a collection of tab stop addresses. Initial stop is the green list 52, followed by the yellow list 54, and the red list 56, then the Date Field 38, the Target Section 40, and finally the Lookup Box 34 from which the tab stop cycle repeats. Within the lists 52,54,56, the keyboard's up and down arrows allow scrolling through the list 52,54,56, and the enter key allows the user to change the consumption count. Within the Date Field 38, the right and left arrow keys navigate among subfields, and up and down arrow keys change values. In operation, a user is first asked to identify him or herself, either by selecting their name or identifier from a list of registered users, or by creating a new registration. This feature enables the program to store and display user-specific information, including, for example, Target Values, planned menus, and summaries of past consumption. The current user's name will appear in the Title Bar 30. The program defaults to the current date; however, any desired date may be entered in the Date Field 38 or selected from the calenderic Summary Section 42. This feature is particularly useful where the user has not entered data on a daily basis and seeks to update their consumption history. Upon start-up, a diet tip or hint is presented. The user may ask for additional hints, or turn off the hint feature. Furthermore, the user may alter, add, or remove diet hints, as desired. The user may then set, in the Target Section 40, nutrition Targets Values for that date. In the illustrated example, calorie and fat content are the values of interest. The Target Values are used as threshold values in the consumption summaries. Once the Target Values are set, the user may proceed to investigate consumables from the scrollable lists 52,54,56. When the user cannot find a particular consumable in the lists 52,54,56 or finds that the lists 52,54,56 are inconveniently cluttered with consumables infrequently or never consumed, the user may add a consumable to or delete a consumable from the database. This feature is useful for adapting the database to the user's eating preferences and habits. In extreme situations, the entire existing database may be deleted and a variety of alternative consumables added. Thus, for example, the program can be easily adapted to be applicable to any person of any culture in any city or region of any country. Similarly, the user may change the nutrition content information for a particular consumable. This latter feature is particularly useful where ingredients, preparation, or serving size has been changed to result in a consumable having different nutrition characteristics. The user may select a particular consumable from the lists 52,54,56 by double-clicking it or highlighting it and selecting Add 1 from the Menu menu 46 to indicate that one or more instances of the consumable has been or will be consumed. The selected consumable and its associated nutrition information is then added to the consumption history. The user may also remove or deselect an inadvertently or mistakenly selected consumable by highlighting it and selecting Remove 1 from the Menu menu 46. As the user enters or edits consumption data for a particular date, the fat and calorie values in that day cell 76 change to reflect the consumption in light of the Target Values. Furthermore, the corresponding month cell 74 will change, as described above, to reflect that data has been entered for a day of that month. At any time, the user may preview or print a report of consumption over a specified time period, such as, for example, a day, week, month, or year. The program may be set to format the report based upon menu order, date order, or other ordering interest. The report provides greater detail, including a breakdown of consumables, than the summarized information provided in the Summary Section 42. From the preceding description, it can be appreciated that the present invention provides a computer program and method for dynamically and interactively providing nutrition content information for consumables such that a user may monitor, tailor, and plan their intake thereof in light of a health-related interest or concern, such as, for example, weight loss, diabetes or other nutrition affected illnesses, or food allergies. Although the invention has been described with reference to the preferred embodiment illustrated in the attached drawings, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. Those skilled in the art will appreciate, for example, that though described herein in terms of menu planning, wherein calorie and fat intake is of prime consideration, the present invention has application to menu planning wherein other food characteristics are emphasized. For example, an equally preferred version of the present invention may be tailored to menu planning for persons with particular allergies; illnesses, such as diabetes; or disabilities affected by the consumption of certain foods. Having thus described the preferred embodiment of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following: | <SOH> BACKGROUND OF THE INVENTION <EOH>1. FIELD OF THE INVENTION The present invention relates to a computer program, method, or system for providing nutrition content information for consumables. More particularly, the present invention relates to a computer program, method, or method for dynamically and interactively providing nutrition content information for consumables such that a user may monitor, tailor, plan, and review their intake thereof in light of a health-related interest or concern, such as, for example, weight loss, food allergies, or diabetes or other nutrition-affected illnesses or disabilities. 2. DESCRIPTION OF THE PRIOR ART It is often desirable to monitor nutrition content of consumables, including, for example, calories, fat, sugar, protein, or carbohydrates. This is particularly true where such nutrition content may affect a health-related interest or concern, including, for example, weight loss, food allergies, or diabetes or other nutrition-affected illnesses or disabilities. Relatedly, it is further desirable to plan future consumption based upon nutrition content, and to review past consumption summarized for a specifiable time period. Various print resources exist to facilitate monitoring nutrition content. Books, for example, provide long lists of consumables and related nutrition information. Furthermore, most packaged consumables provide nutrition information on the packaging. Unfortunately, print resources suffer from a number of limitations and disadvantages. Books, for example, are bulky and difficult to conveniently tailor for efficient use by any particular person (short of adding or removing pages), which reduces likelihood of consistent use. Package-based information is, of course, limited to packaged foods. Furthermore, print resources are generally unable to practically present nutrition information in a visually descriptive manner operable to conveniently impart to a user a sense of a particular consumable's place in an overall monitoring scheme. Additionally, print resources are generally unable to practically provide a convenient mechanism whereby future consumption can be dynamically planned and past consumption can be reviewed. It is known to use computers and computer programs to facilitate monitoring and planning intake of consumables. Existing programs, however, are typically non-interactive and non-dynamic and therefore inconvenient and awkward to use, which may decrease compliance and effectiveness. Furthermore, existing programs typically do not allow for substantial modification or customization to suit users' particular consumption habits or preferences, which may make the program inapplicable to or unuseable by some people or cultures. Due to the above identified problems and shortcomings in the existing art, an improved computer program or method is needed for monitoring nutrition information of consumables and intake thereof. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a computer program, method, and system for dynamically and interactively providing nutrition content information for consumables such that a user may monitor, tailor, plan, and review their intake thereof in light of a health-related interest or concern, such as, for example, weight-loss, food allergies, or diabetes or other nutrition affected illnesses or disabilities. Nutrition content of interest may include, for example, protein, carbohydrates, fat, vitamins, minerals, calories, sugar, etc. Consumables are categorized according to a predetermined scheme of categorization, and the categories are displayed as scrollable and searchable lists. The lists are associated with an appropriate color to draw attention to the categories' relative nutrition content and to facilitate quicker and easier evaluation of a consumable of interest. Furthermore, menus may be planned in advance wherein projected intake of particular consumables is recorded. Additionally, summaries are provided of actual intake in light of a pre-established target intake for a particular day, week, month, or other user-specifiable time period. The lists of consumables and associated nutrition content information are stored in a database customizable with regard to adding or deleting consumables and editing the nutrition content information. Thus, the user is able to adapt the program to more personally reflect their eating habits and preferences. For example, a user who does not eat meat may delete all meat items from the database in order to make finding and selecting non-meat consumables more convenient; and a user who uses low-fat or no-sugar ingredients or who reduces calories by baking rather than frying may edit the nutrition content information to reflect the change. Furthermore, users from different cultures may tailor the database to include consumables specific to that culture. As mentioned, the consumables are categorized according to a predetermined scheme of categorization based upon the user's health-concern or interest. For example, where the user desires to monitor calorie and fat content to facilitate weight loss, the consumables may be divided into three groups—low, medium, and high calorie and fat content—and the groups associated with an appropriately recognizable display color, such as green for low or safe or desirable, yellow for medium or warning, and red for high or dangerous or generally undesirable with regard to the nutrition content of interest, to facilitate the user's recognition and understanding of any particular consumable's effect, relative to other consumables, on the user's goals. Though the computer program and method may be implemented on any computing device, including, for example, a desktop or laptop personal computer, in a preferred embodiment the computer program is stored on and executed by a small, portable, battery-power, dedicated hand-held device. Because the small hand-held device is more conveniently and less conspicuously carried than a conventional desktop of laptop computer, the user is more likely to enter more consumption data at the time of consumption or shortly thereafter, thereby greatly increasing proper and consistent use of the present invention. These and other advantages of the present invention are further described in the section entitled DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT, below. | 20040712 | 20051011 | 20050113 | 57541.0 | 1 | WOLFE JR, WILLIS RAY | COMPUTER PROGRAM, METHOD, AND SYSTEM FOR MONITORING NUTRITION CONTENT OF CONSUMABLES AND FOR FACILITATING MENU PLANNING | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,889,631 | ACCEPTED | Process cartridge and electrophotographic image forming apparatus | A process cartridge and an electrophotographic image forming apparatus incorporating the same. The process cartridge includes an electrophotographic photosensitive member, a container supplying a developer to the electrophotographic photosensitive member, a cleaning member including a blade and a support portion supporting the blade, the blade selectively contacting the electrophotographic photosensitive member to remove the developer from the electrophotographic photosensitive member, and a cartridge frame supporting the electrophotographic photosensitive member and the support portion, the cartridge frame including a contact portion contacting the support portion under external forces on the cartridge frame to prevent deformation of the cartridge frame. | 1. A process cartridge for use in an electrophotographic image forming apparatus, the process cartridge comprising: an electrophotographic photosensitive member; a cleaning member including a blade and a support portion supporting the blade, the blade contacting the electrophotographic photosensitive member to remove a developer from the electrophotographic photosensitive member; and a cartridge frame supporting the electrophotographic photosensitive member and the support portion, the cartridge frame including a contact portion contacting the support portion under external forces on the cartridge frame to prevent deformation of the cartridge frame. 2. A process cartridge according to claim 1, wherein the support portion is a metal plate disposed along a length of the cartridge frame. 3. A process cartridge according to claim 1, wherein the contact portion contacts at about a center of the support portion, along the length of the cartridge frame. 4. A process cartridge according to claim 3, wherein the contact portion includes a rib projecting from the frame to contact the support portion. 5. A process cartridge according to claim 1, wherein a clearance is provided between the contact portion and the support portion when no external forces are applied to the cartridge frame. 6. A process cartridge according to claim 1, wherein an end of the support portion is fixed to the cartridge frame with a screw. 7. A process cartridge according to claim 1, further comprising: a storage portion storing the developer removed by the blade; a developing member developing an electrostatic latent image formed on the electrophotographic photosensitive member; and a container supplying the developer to the electrophotographic photosensitive member; wherein the cartridge frame includes first and second frames, the first frame supporting the electrophotographic photosensitive member, the cleaning member, and the storage portion, and the second frame supporting the developing member and the container. 8. A process cartridge according to claim 7, wherein the first frame is oriented higher relative to the second frame when the process cartridge is mounted to the apparatus. 9. A process cartridge according to claim 7, wherein the cartridge frame is adapted for grasping by a user's hand. 10. An electrophotographic image forming apparatus for forming an image on a recording medium, the apparatus comprising: (i) a detachable process cartridge comprising: an electrophotographic photosensitive member; a container supplying a developer to the electrophotographic photosensitive member; a developing member developing an electrostatic latent image formed on the electrophotographic photosensitive member; a cleaning member including a blade and a support portion supporting the blade, the blade selectively contacting the electrophotographic photosensitive member to remove the developer from the electrophotographic photosensitive member; a cartridge frame supporting the electrophotographic photosensitive member and the support portion, the cartridge frame including a contact portion contacting the support portion under external forces on the cartridge frame to prevent deformation of the cartridge frame; (ii) an intermediate transfer member receiving the developed electrostatic latent image from the electrophotographic photosensitive member and transferring the image onto the recording medium; and (iii) feeding means for feeding the recording medium to the intermediate transfer member. 11. An electrophotographic image forming apparatus according to claim 10, wherein the contact portion includes a rib projecting from the frame to contact the support portion. 12. An electrophotographic image forming apparatus according to claim 10, wherein the cartridge frame includes first and second frames, the first frame supporting the electrophotographic photosensitive member, the cleaning member, and the storage portion, and the second frame supporting the developing member and the container. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus and a process cartridge for use with the electrophotographic image forming apparatus. 2. Description of the Related Art An electrophotographic image forming apparatus is an apparatus for forming an image onto a recording medium by an electrophotographic image forming system. Examples of such apparatuses include electrophotographic copying machines, electrophotographic printers (e.g., laser-beam printers, LED printers), facsimile machines, and word processors. A process cartridge can include at least cleaning means and an electrophotographic photosensitive drum, and can be detachably mounted to the body of the image forming apparatus. Conventional electrophotographic image forming apparatuses using an electrophotographic image forming process adopt a process cartridge system in which an electrophotographic photosensitive member and process means for the electrophotographic photosensitive member are integrated in a cartridge, which can be detachably mounted to an image forming apparatus body. With such process cartridge system, users can themselves maintain the apparatus and do not require repair people, thus significantly improving ease of use. Such process cartridge system is widely used in image forming apparatuses. Recently, multicolor-image forming apparatuses utilize a plurality of process cartridges of different colors. Providing the plurality of process cartridges detachable to the image forming apparatus body improves ease of use for users. The multicolor-image forming apparatus can be personalized by vertically disposing a plurality of process cartridges to reduce its installation area in view of space saving. The image forming apparatus with the above structure may have a flat process cartridge to reduce the height. For this purpose, for example, a technique for cleaning means is disclosed in Japanese Patent Laid-Open No. 10-301460 in which waste toner, which is a transfer residual developer agent, is carried horizontally and a waste-toner storage chamber is formed in a flat shape. With the above-described structure, the rigidity of the part where the waste-toner storage means is disposed becomes lessened. As such, when the user strongly grasps the process cartridge, the waste-toner storage chamber may be deformed. SUMMARY OF THE INVENTION The present invention is directed to a compact process cartridge configured such that, when a user grasps the process cartridge, a frame of the process cartridge is prevented from substantially deforming. The present invention is directed to a compact process cartridge configured such that, when a user grasps the process cartridge, leakage of developer from the process cartridge is prevented. The present invention is also directed to an electrophotographic image forming apparatus to which the process cartridge is detachably mounted. In one aspect of the present invention, the process cartridge includes an electrophotographic photosensitive member, a cleaning member including a blade and a support portion supporting the blade, the blade contacting the electrophotographic photosensitive member to remove the developer from the electrophotographic photosensitive member, and a cartridge frame supporting the electrophotographic photosensitive member and the support portion, the cartridge frame including a contact portion contacting the support portion under an external force on the cartridge frame to prevent deformation of the cartridge frame. In one embodiment, the contact portion includes a rib projecting from the frame to contact the support portion. Further features and advantages of the present invention will become apparent from the following description of the embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a cleaning unit according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a color image-forming apparatus in accordance with one embodiment of the present invention. FIG. 3 is a schematic diagram of process cartridges used in the color image-forming apparatus shown in FIG. 2. FIG. 4 is a cross-sectional view of the overall structure of a process cartridge. FIG. 5 is a perspective view of the structure of the process cartridge. FIG. 6 is a perspective view of the process cartridge. FIG. 7 is a partial perspective view of a cleaning unit according to the invention. FIG. 8 is a perspective view showing the relationship between a cleaning frame and a sealing member according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT A developer unit, a process cartridge, and an image forming apparatus including the same according to an embodiment of the present invention will now be described. [Overall Structure of Color-Image Forming Apparatus] The overall structure of a color-image forming apparatus will be schematically described with reference to FIGS. 2 and 3. FIG. 2 is a schematic diagram of a color image-forming apparatus 200 in accordance with one embodiment of the present invention. The color image-forming apparatus 200 can be a color laser printer, for example. FIG. 3 is a schematic diagram of process cartridges 7 used in the color image-forming apparatus 200 shown in FIG. 2. Referring to FIG. 2, the color laser printer 200 includes an image forming section having photosensitive drums 1a, 1b, 1c, and 1d (collectively referred to as photosensitive drum 1) for each of yellow, magenta, cyan, and black colors, respectively. The printer 200 also includes an intermediate transfer member 5 that holds a color image developed by the image forming section and transferred in multiple colors. The intermediate transfer member 5 transfers the color image to a recording medium (transfer material) P fed by feeding means. The photosensitive drums 1a, 1b, 1c, and 1d are rotated counterclockwise in the drawing by driving means (not shown). Around the photosensitive drum 1 is provided in the rotating direction charging means 2 (2a, 2b, 2c, and 2d) for uniformly charging the surface of the photosensitive drum 1 with electricity, a scanner unit 3 (3a, 3b, 3c, and 3d) for emitting a laser beam according to image information to form an electrostatic latent image on the photosensitive drum 1, a developer unit 4 (4a, 4b, 4c, and 4d) for applying toner, which is a developer agent, to the electrostatic latent image to develop it as a toner image, and a photoconductor unit 6 (6a, 6b, 6c, and 6d) for transferring the toner image on the photosensitive drum 1 to a primary transfer region T1 of the intermediate transfer member 5. The photoconductor unit 6 includes a cleaning unit for removing residual toner left on the surface of the photosensitive drum 1 after transfer. The toner image transferred to the intermediate transfer member 5 is further transferred onto the recording medium P with a transfer roller 13 at a transfer region T2. The recording medium P onto which the color image has been transferred is carried to fixing means 8, in which the color image is fixed to the recording medium P. The recording medium P is then discharged to an output tray 26 by discharge rollers 25. The photosensitive drum 1, charging means 2, the developer unit 4, and the photoconductor unit 6 are integrated into a process cartridge 7. Referring to FIG. 3, an image-forming apparatus body 100 includes an opening cover 29 integrated with the intermediate transfer member 5. The process cartridge 7 can be mounted to or dismounted from the image-forming apparatus body 100 when the opening cover 29 is opened and the photosensitive drum 1 set on this side. The components of the image forming apparatus 200 will be specifically described hereinafter. [Photosensitive Drum] The photosensitive drum 1 will now be described in detail. The photosensitive drum 1 includes an organic photoconductor (OPC) layer applied onto an outer surface of an aluminum cylinder with a diameter of, for example, 30 mm. The ends of the photosensitive drum 1 are rotatably supported by a supporting member (not shown). A drive motor (not shown) transmits a drive force to one or both ends of the drum 1 to drive the photosensitive drum 1 in a counterclockwise direction, for example. [Charging Means] The charging means 2 employs a contact-roller electrifying system. The charging means 2 is a conductive roller that is brought into contact with the surface of the photosensitive drum 1 to uniformly charge the surface of the photosensitive drum 1 with electricity by applying charging bias to the charging means 2. [Exposure Means] The scanner unit 3 serving as exposure means emits an image light corresponding to an image signal to the polygon mirror 9 (9a, 9b, 9c, and 9d), which is rotated at a high speed by a scanner motor. The image light reflected by the polygon mirror 9 selectively exposes the surface of the photosensitive drum 1 rotating at a fixed speed with light through an imaging lens, thereby forming an electrostatic latent image onto the photosensitive drum 1. [Developer Unit] The developer unit 4 includes a toner container 41 that accommodates yellow, magenta, cyan, and black toners to visualize the electrostatic latent image. The toners in the toner container 41 are fed to a toner supply roller 43 with a toner mixing and feeding mechanism 42. The toner supply roller 43 rotates clockwise in the Z-direction and is in pressure contact with a developing roller 40. Electrically charged toner is applied to the outer surface of the developing roller 40, which is rotating clockwise (in the Y-direction), via a developing blade 44 and the toner supply roller 43. A developing bias is applied to the developing roller 40 facing the photosensitive drum 1 on which an electrostatic latent image is formed, thereby developing the latent image. [Intermediate Transfer Member] The intermediate transfer member 5 rotates clockwise in synchronization with the outer speed of the photosensitive drum 1, as shown in FIG. 2. A primary transfer roller 12 (12a, 12b, 12c, and 12d) is disposed to face the photosensitive drum 1 with the intermediate transfer member 5 sandwiched therebetween. The toner image formed on the photosensitive drum 1 is transferred onto the intermediate transfer member 5 by application of voltage to the primary transfer roller 12. The intermediate transfer member 5, which receives the transferred image, then transfers the toner image onto the recording medium P via the transfer roller 13 having an applied voltage. The intermediate transfer member 5 (intermediate transfer belt) according to the embodiment is stretched over a driving roller 14, a transfer opposing roller 15, and a tension roller 16. The intermediate transfer member 5 is supported to the apparatus body 100 with the driving roller 14 as the fulcrum. The driving force of the drive motor (not shown) is transmitted to the intermediate transfer member 5 at one end of the driving roller 14 to rotate the intermediate transfer member 5 clockwise (in the direction of the arrow) with the image forming operation. [Feeding Means] The feeding means feeds the recording medium P to the image forming section. The feeding means includes a cassette 17, a feed roller 18, a separation pad 19, a guide 20, and a registration roller pair 21. During an image forming operation, the feed roller 18 rotates to feed the recording medium P in the cassette 17 one by one. The recording medium P is guided by the guide 20 and passes through the feed roller 18 to reach the registration roller pair 21. During the image forming operation, the registration roller pair 21 performs a stop operation to stop the recording medium P in standby mode, performs a rotating operation of feeding the recording medium P towards the intermediate transfer member 5 in a predetermined sequence, and also adjusts the transfer position of the image for transferring on the recording medium in the following process. [Transfer Means] A transfer means includes the movable transfer roller 13. The transfer roller 13 contacts the intermediate transfer member 5 with a specified pressure during transfer of a color image onto the recording medium P. At the same time, the transfer roller 13 is provided with a bias so that the toner image on the intermediate transfer member 5 is transferred onto the recording medium P. The recording medium P is transferred to the left at a specified speed during the transfer operation, towards the fixing means 8. [Fixing Means] The fixing means 8 fixes the toner image formed on the recording medium P. Specifically, the fixing means 8 includes a film guide unit 23 having a built-in ceramic heater for heating the recording medium P and a pressure roller 24 for bringing the recording medium P into pressure contact with the film guide unit 23. [Image Forming Operation] The operation of image formation with the apparatus constructed above will be described. The feed roller 18, shown in FIG. 2, is rotated to separate one recording medium P in the cassette 17 and carry it to the registration roller pair 21. The photosensitive drum 1 and the intermediate transfer member 5 are individually rotated in the direction of the arrow at a predetermined circumferential speed V (hereinafter, referred to as a process speed). The surface of the photosensitive drum 1, which is uniformly electrified by the charging means 2, is exposed to laser light to form an image. Latent-image formation, development, and toner transfer to the intermediate transfer member 5 are each performed in the respective primary transfer positions T1 in the order of yellow, magenta, cyan, and black, forming a full-color image made of four toners (yellow, magenta, cyan, and black colors) on the surface of the intermediate transfer member 5. The full-color image on the intermediate transfer member 5 is transferred onto the recording medium P with all the four colors at the same time. The recording medium P that has passed through the transfer region T2 is separated from the intermediate transfer member 5, carried to the fixing means 8, and discharged to the output tray 26 through the discharge rollers 25 after toner fixing operation. The image forming operation is thus finished. [Structure of Process Cartridge] A process cartridge embodying the present invention will be specifically described with reference to FIGS. 4 and 5. FIG. 4 is a main cross-sectional view of the process cartridge 7 which accommodates toner. FIG. 5 is a perspective view of the process cartridge 7. FIG. 6 is a perspective view of the process cartridge. The respective process cartridges 7a, 7b, 7c, and 7d of yellow, magenta, cyan, and black colors have the same structure. As shown in FIGS. 4 and 5, the process cartridge 7 is divided into the photoconductor unit 6 and the developer unit 4. The photoconductor unit 6 includes the photosensitive drum 1, the charging means 2, and a cleaning blade 60. The developer unit 4 includes the developing roller 40 for developing the electrostatic latent image on the photosensitive drum 1. The photosensitive drum 1 of the photoconductor unit 6 is rotatably mounted to a cleaning frame 61 through a bearing member 31. Disposed around the outer surface of the photosensitive drum 1 is the charging means 2 for uniformly charging the surface of the photosensitive drum 1 with electricity and the cleaning blade 60 for removing the toner remaining on the photosensitive drum 1. The blade 60 includes an elastic cleaning portion 60a that contacts the photosensitive drum 1, and a support plate 60b fixed to the cleaning frame 61 for supporting the cleaning portion 60a. The material for the cleaning portion 60a can be an elastomer such as urethane and silicone, which is a urethane rubber with a hardness of 710 (Wallace) in this embodiment. The support plate 60b can be made of a rigid material, such as a cold rolled steel sheet of t=1.6. If the contact pressure of the blade 60 on the photosensitive drum 1 is not uniform in the longitudinal direction, there may be incomplete cleaning which has significant effects on the image quality. As such, the blade 60 is accurately fixed to the cleaning frame 61. The residual toner removed from the surface of the photosensitive drum 1 with the blade 60 is sequentially carried to a waste-toner chamber 63 provided at the rear of the cleaning frame 61 with a toner-carrying mechanism 62. The driving force of the drive motor (not shown) at one end of the rear is transmitted to the photosensitive drum 1 to rotate the photosensitive drum 1 counterclockwise during the image forming operation. The developer unit 4 includes the developing roller 40 that contacts the photosensitive drum 1 and rotates in the direction of arrow Y. The developer unit 4 also includes the toner container 41 for accommodating toner, and a developer container 45. The developing roller 40 is rotatably supported by the developer container 45 with developer bearings 47 and 48. On the outer surface of the developing roller 40 is disposed the toner supply roller 43, which rotates in the direction of arrow Z, and the developing blade 44. The toner container 41 includes the toner mixing and feeding mechanism 42 therein for mixing the accommodated toners and carrying them to the toner supply roller 43. As shown in FIG. 5, the developer unit 4 is provided with support holes 49 at the developer bearings 47 and 48. The developer unit 4 has a suspension structure rotatably supported to the photoconductor unit 6 with support pins 49a and the support holes 49. Without the process cartridge 7 mounted to a printer body, the developer unit 4 is constantly biased by a pressure spring 64 so that the developing roller 40 is brought into contact with the photosensitive drum 1 around the support pins 49a (refer to FIG. 4). During a developing operation, the accommodated toner is carried to the toner supply roller 43 via the toner mixing and feeding mechanism 42. The toner supply roller 43, which rotates in the direction of arrow Z, feeds the toner onto the developing roller 40 by sliding friction with the developing roller 40, which is rotating in the direction of arrow Y. The toner is thus supplied onto the developing roller 40. The toner on the developing roller 40 is moved to the developing blade 44 as the developing roller 40 rotates. The developing blade 44 applies an electrical charge to the toner to form them into a specified thin layer of toner. The toner is then carried to a developing section where the photosensitive drum 1 and the developing roller 40 are in contact with each other. The toner adhers to the electrostatic latent image formed on the surface of the photosensitive drum 1 by a direct-current developing bias applied from a power source (not shown) to the developing roller 40, thereby developing the latent image. Toner that does not contribute to the development and remains on the surface of the developing roller 40 is returned into the developer unit 4. As the developing roller 40 rotates, the toner is separated and collected from the developing roller 40 at the sliding frictional section with the toner supply roller 43. The collected toner is mixed with remaining toners by the toner mixing and feeding mechanism 42. In the contact developing system for developing by the contact of the photosensitive drum 1 and the developing roller 40, the photosensitive drum 1 can be a rigid member and the developing roller 40 can be an elastic member. The elastic member includes a single solid-rubber layer and a resin coating on the solid rubber layer in view of a toner electrizing characteristic. The toner supply roller 43 is an elastic roller made of a core metal and a sponge, of which the sponge is formed of continuously foamed sponge. EMBODIMENTS OF THE INVENTION The structure of an image forming apparatus according to the present invention and a process cartridge used therein will be specifically described with reference to FIGS. 1 to 4. PRINCIPAL STRUCTURE OF THE INVENTION FIG. 1 is a perspective view of a cleaning unit according to an embodiment of the present invention. FIG. 7 is a partial perspective view of the cleaning unit according to the invention. FIG. 8 is a perspective view showing the relationship between a cleaning frame and a sealing member according to the invention. The cleaning frame 61 includes an upper plate 61a, opposite side plates 61b and 61c, a front wall 61d, and cleaning-blade support portions 61e and 61f. The waste-toner chamber 63 is provided at the rear of the cleaning frame 61. Opposite ends 60b1 and 60b2 of the support plate 60b of the cleaning blade 60 are fixed to the opposite ends 61e and 61f of the cleaning frame 61 with fixing members such as screws 66. Thus, the cleaning blade 60 is in contact with the photosensitive drum 1 supported by the cleaning frame 61. The upper plate 61a has a downward rib 65 at the center, which is a contact portion. The rib 65 has an end 65a which is adjacent to the center 60b3 of the cleaning-blade support plate 60b. The distance between the end 65a and the center 60b3 of the cleaning-blade support plate 60b is within the range of 0 to 1 mm, for example, which is set at 0.5 mm in this embodiment. This structure provides a support between the rigid metal plate and the upper plate 61a of the cleaning frame 61 even if a user strongly grasps the process cartridge vertically, thus eliminating the possibility of leakage of waste toner. Also, a very small space is provided between the end of the rib 65 provided to the cleaning frame 61 and the cleaning-blade support plate 60b. This prevents application of a force that will deform the cleaning blade 60 during image forming operation, thus providing a preferable image. As described above, according to the embodiment, even a compact flat process cartridge can have sufficient rigidity without causing leakage of waste toner. In this embodiment, no undesired force is applied to the cleaning member during image formation, thus providing a preferable image. As described above, according to the embodiment, a more compact process cartridge can be provided and the deformation of the cartridge frame can be prevented when it is grasped. While the present invention has been described with reference to what are presently considered to be the embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus and a process cartridge for use with the electrophotographic image forming apparatus. 2. Description of the Related Art An electrophotographic image forming apparatus is an apparatus for forming an image onto a recording medium by an electrophotographic image forming system. Examples of such apparatuses include electrophotographic copying machines, electrophotographic printers (e.g., laser-beam printers, LED printers), facsimile machines, and word processors. A process cartridge can include at least cleaning means and an electrophotographic photosensitive drum, and can be detachably mounted to the body of the image forming apparatus. Conventional electrophotographic image forming apparatuses using an electrophotographic image forming process adopt a process cartridge system in which an electrophotographic photosensitive member and process means for the electrophotographic photosensitive member are integrated in a cartridge, which can be detachably mounted to an image forming apparatus body. With such process cartridge system, users can themselves maintain the apparatus and do not require repair people, thus significantly improving ease of use. Such process cartridge system is widely used in image forming apparatuses. Recently, multicolor-image forming apparatuses utilize a plurality of process cartridges of different colors. Providing the plurality of process cartridges detachable to the image forming apparatus body improves ease of use for users. The multicolor-image forming apparatus can be personalized by vertically disposing a plurality of process cartridges to reduce its installation area in view of space saving. The image forming apparatus with the above structure may have a flat process cartridge to reduce the height. For this purpose, for example, a technique for cleaning means is disclosed in Japanese Patent Laid-Open No. 10-301460 in which waste toner, which is a transfer residual developer agent, is carried horizontally and a waste-toner storage chamber is formed in a flat shape. With the above-described structure, the rigidity of the part where the waste-toner storage means is disposed becomes lessened. As such, when the user strongly grasps the process cartridge, the waste-toner storage chamber may be deformed. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to a compact process cartridge configured such that, when a user grasps the process cartridge, a frame of the process cartridge is prevented from substantially deforming. The present invention is directed to a compact process cartridge configured such that, when a user grasps the process cartridge, leakage of developer from the process cartridge is prevented. The present invention is also directed to an electrophotographic image forming apparatus to which the process cartridge is detachably mounted. In one aspect of the present invention, the process cartridge includes an electrophotographic photosensitive member, a cleaning member including a blade and a support portion supporting the blade, the blade contacting the electrophotographic photosensitive member to remove the developer from the electrophotographic photosensitive member, and a cartridge frame supporting the electrophotographic photosensitive member and the support portion, the cartridge frame including a contact portion contacting the support portion under an external force on the cartridge frame to prevent deformation of the cartridge frame. In one embodiment, the contact portion includes a rib projecting from the frame to contact the support portion. Further features and advantages of the present invention will become apparent from the following description of the embodiments with reference to the attached drawings. | 20040712 | 20060404 | 20050127 | 70165.0 | 0 | GRAINGER, QUANA MASHELLE | RIGID PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS INCORPORATING THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,889,637 | ACCEPTED | Form processing method, form processing program, and form processing apparatus | A form processing method edits at least one target field in a form. The form processing method determines the type of the form, determines whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type of form, and edits the target field interdependently with the related field, if it is determined that the editing instruction is given to edit the target field interdependently with the related field. | 1. A form processing method of editing at least one target field in a form, the form processing method comprising the steps of: determining a type of the form; determining whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the form type is a predetermined form type; and editing the target field interdependently with the related field if it is determined that the editing instruction is given to edit the target field interdependently with the related field. 2. The form processing method according to claim 1, wherein the target field is a cell included in a table in the form and the table has at least one row. 3. The form processing method according to claim 2, wherein the target field is a data cell to which field data is input, and the related field is a summary cell where the field data input in the data cell for each of the rows in the table is summed. 4. The form processing method according to claim 3, wherein, if it is determined that the editing instruction is given to edit the target field interdependently with the related field and the editing instruction is an instruction to change a width of the data cell, the width of the data cell is changed interdependently with the width of the summary cell. 5. The form processing method according to claim 3, wherein, if it is determined that the editing instruction is given to edit the target field interdependently with the related field and the editing instruction is an instruction to add at least one data cell, the data cell is added interdependently with a corresponding summary cell. 6. The form processing method according to claim 3, wherein, if it is determined that the editing instruction is given to edit the target field interdependently with the related field and the editing instruction an instruction to delete at least one data cell, the data cell is deleted interdependently with at least one corresponding summary cell. 7. A form processing method of editing at least one target field in a form of a first type of form having data rows each containing a number of data cells, the form processing method comprising the steps of: determining whether an instruction is given to change the form from the first type of form to a second type of form; if it is determined that the instruction is given to change the form from the first type of form to the second type of form, determining whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, the data calls and the summary cell being cells included in a table in the form; and if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, converting the table such that a position of a split line of the summary row is aligned with a position of a corresponding split line of the data row; and if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row, converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row. 8. The form processing method according to claim 7, wherein, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row, converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row, adding at least one summary cell to a predetermined position in the summary row if the number of summary cells in the summary row is less than the number of data cells in the data row, and deleting at least one summary cell from a predetermined position in the summary row if the number of summary cells in the summary row is greater than the number of data cells in the data row. 9. A form processing program including program code that causes a computer to edit at least one target field in a form, the computer code comprising the steps of: determining a type of the form; determining whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the form type is a predetermined form type; and editing the target field interdependently with the related field if it is determined that the editing instruction is given to edit the target field interdependently with the related field. 10. A form processing program including program code that causes a computer to edit at least one target field in a form, the computer code comprising the steps of: determining whether an instruction is given to change the form from the first type of form to a second type of form; if it is determined that the instruction is given to change the form from the first type of form to the second type of form, determining whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, the data calls and the summary cell being cells included in a table in the form; and if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, converting the table such that a position of a split line of the summary row is aligned with a position of a corresponding split line of the data row; and if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row, converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row. 11. A form processing apparatus for editing at least one target field in a form, the form processing apparatus comprising: a form determining unit configured to determine a type of the form; a determining unit configured to determine whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type; and an editing unit configured to edit the target field interdependently with the related field, if it is determined that the editing instruction is given to edit the target field interdependently with the related field relating to the target field. 12. A form processing apparatus for editing at least one target field in a form, the form processing apparatus comprising: a form determining unit configured to determine whether an instruction is given to change the type of the form; a number-of-cells determining unit configured to determine whether a number of data cells in each data row to which field data is input is equal to a number of summary cells in a summary row where the field data input in the data cells is summed, if the instruction is given to change the type of the form to a predetermined type of form, the data calls and the summary cell being cells included in a table in the form; and a converting unit configured to convert the table such that a position of a split line of the summary row is aligned with a position of a corresponding split line of the data row, if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, and to convert the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row. | This application claims priority from Japanese Patent Application No. 2003-274006 filed Jul. 14, 2003, which is incorporated hereby by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a form processing method, a form processing program, and a form processing apparatus for use in editing forms. 2. Description of the Related Art Heretofore, in order to output a form, data in a data file has been input into a predetermined field in a form file (standard template) indicating the layout of the form to create the output form. Such a method is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2001-283140. A graphic indicating a field to which data is input is referred to herein as a field graphic, and data in a data file is referred to herein as field data. A form including a table can be created by using such field graphics. However, there may be restrictions on the layout of fields in the form depending on the type of form (form file). Therefore, a user must be aware of the restrictions corresponding to the type of form in order to create a desired form. Such restrictions require a significant amount of time and effort of the user. SUMMARY OF THE INVENTION A form processing method, a form processing program, and a form processing apparatus, which are capable of easily editing fields (particularly, fields included in a table) in a form file in the editing of a form are disclosed. According to an aspect of the present invention, a form processing method edits at least one target field in a form. The form processing method includes the steps of determining the type of the form; determining whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type of form; and editing the target field interdependently with the related field, if it is determined that the editing instruction is given to edit the target field interdependently with the related field relating to the target field. According to another aspect of the present invention, a form processing method edits at least one target field in a form. The form processing method includes the steps of determining whether an instruction is given to change the type of the form; determining whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, if the instruction is given to change the type of the form to a predetermined type of form, the data calls and the summary cell being cells included in a table in the form; and converting the table such that the position of a split line of the summary row is aligned with the position of a corresponding split line of the data row, if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, and converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row. According to another aspect of the present invention, a form processing program includes program code that causes a computer to edit at least one target field in a form. The computer code includes the steps of determining the type of the form; determining whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type of form; and editing the target field interdependently with the related field if it is determined that the editing instruction is given to edit the target field interdependently with the related field. According to another aspect of the present invention, a form processing program includes program code that causes a computer to edit at least one target field in a form. The computer code includes the steps of determining whether an instruction is given to change the type of the form; determining whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, if the instruction is given to change the type of the form to a predetermined type of form, the data calls and the summary cell being cells included in a table in the form; and converting the table such that the position of a split line of the summary row is aligned with the position of a corresponding split line of the data row, if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, and converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row. According to another aspect of the present invention, a form processing apparatus is configured to edit at least one target field in a form. The form processing apparatus includes a form determining unit configured to determining the type of the form; a determining unit configured to determine whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type of form; and an editing unit for editing the target field interdependently with the related field, if it is determined that the editing instruction is given to edit the target field interdependently with the related field relating to the target field. According to another aspect of the present invention, a form processing apparatus is configured to edit at least one target field in a form. The form processing apparatus includes a form determining unit configured to determine whether an instruction is given to change the type of the form; a number-of-cells determining unit configured to determine whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, if the instruction is given to change the type of the form to a predetermined type of form, the data calls and the summary cell being cells included in a table in the form; and a converting unit configured to convert the table such that the position of a split line of the summary row is aligned with the position of a corresponding split line of the data row, if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, and for converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row. According to the present invention, it is possible for a user to perform editing without being aware of whether his editing instructions conform to the format (restrictions) corresponding to the type of a form, thus allowing the user to efficiently editing the form. Further features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. FIG. 1 is a block diagram showing an exemplary hardware configuration of a form processing system according to an embodiment of the present invention. FIG. 2 is a diagram showing the contents of a floppy disk (FD). FIG. 3 is a diagram showing a memory map in a state where a control program loaded in a read-only memory (ROM) is executable. FIG. 4 illustrates an example of inputting field data in a field in a form file to generate an output form, according to a first embodiment of the present invention. FIG. 5 illustrates an example of generating an output form including a table. FIG. 6 illustrates an example of editing a form file including a table. FIG. 7 is a flowchart showing a process of editing a table according to the first embodiment. FIG. 8 is a diagram showing a dialog box for selecting a type of form. FIG. 9 illustrates an example in which data rows and a summary row are edited interdependently. FIG. 10 illustrates another example in which data rows and the summary row are edited interdependently. FIG. 11 is a flowchart showing a process of converting a table according to a second embodiment. FIG. 12 illustrates an example in which a table is automatically converted into a general-purpose form. FIG. 13 illustrates a dialog box in which a user can select a method of converting a table into a general-purpose form. FIG. 14 illustrates another example in which a table is automatically converted into a general-purpose form. FIG. 15 illustrates still another example in which a table is automatically converted into a general-purpose form. DESCRIPTION OF THE EMBODIMENTS FIG. 1 is a block diagram showing an exemplary hardware configuration of a form processing system (form processing apparatus) according to an embodiment of the present invention. The form processing system is a computer system that includes a central processing unit (CPU) 10; a main memory including a ROM 11 and a random-access memory (RAM) 12; an external memory including a floppy disk (FD) drive 13 and a hard disk (HD) drive 15; an instruction input device including a pointing device (coordinate indicating device), such as a mouse 18, and a keyboard 16; a display device such as a cathode ray tube (CRT) display 17; a printing device, such as a printer 19 or a plotter; and a system bus 20 connecting the above components. The form processing system is connected to other computer systems via communication lines, for example, a network. The form processing system may be embodied by using an information processor, such as a general workstation or a personal computer. The CPU 10 executes a basic input-output program, an operating system (OS), and a form processing program to activate the form processing system. The basic input-output program is written in the ROM 11 and the OS is written in the HD drive 15. When the form processing system is turned on, the OS is read from the HD drive 15 and read into the RAM 12 by an initial program loading (IPL) function included in the basic input-output program to start the OS operation. The control program (the form processing program) for realizing the form processing system of this embodiment and related data are recorded in an FD 14. FIG. 2 is a diagram showing the contents of the FD 14. The control program executable file and the control program related data recorded in the FD 14 are loaded into the computer system through the FD drive 13, as shown in FIG. 1. When the FD 14 is inserted in the FD drive 13, the control program and related data are read out from the FD 14 and are loaded into the RAM 12 under the control of the OS and the basic input-output program. The control program is then made ready for operating. FIG. 3 is a diagram showing the memory map in a state where the control program loaded in the RAM 12 is executable. Although the control program and related data are read out from the FD 14 and are directly loaded into the RAM 12 in this embodiment, the control program and related data may be stored (installed) in the HD drive 15 in advance and may be read out from the HD drive 15 and loaded into the RAM 12 for operating the control program. The control program may be recorded in a removable storage medium, such as a compact disc read-only memory (CD-ROM) or an integrated circuit (IC) memory card, instead of the FD 14. Alternatively, the control program may be recorded in the ROM 11 as part of the memory map and may be directly executed by the CPU 10. Furthermore, the control program may be read from another device via a network to be executed. First Embodiment FIG. 4 illustrates an example of inputting field data in a field in a form file to generate an output form, according to a first embodiment of the present invention. It is assumed that the output form of the input field data can be specified for each field graphic (specification of output format). Alphabetic characters used for specifying the output form are called output pictures. For example, when “K” is an output picture for specifying that only one alphabetic character is output, not numeric values but alphabetic characters are output from among the input field data. In addition, when five “Ks” are specified, as shown in FIG. 4, field data including up to five alphabetic characters can be output in the corresponding field graphic. According to the first embodiment, a form including a table having a variable size can be created, as shown in FIG. 5. In other words, it is possible to create a form in which the number of rows in a table can be varied depending on the amount of data in the field data. If the table cannot be fit on one page, the table covers a plurality of pages. It is also possible to display the calculation result, such as the sum of the values in a column, by editing the table. FIG. 6 illustrates an example of editing a form file including a table. A mode for use in editing a table is hereinafter referred to as a table editing mode. Headers, each being displayed at the top of the corresponding column in the table, are set in a header row in FIG. 6. A user can arbitrarily change the contents of each header cell, such as “article name”. Data read from the field data is input in a data row. A plurality of data rows are created depending on the amount of data. Table cells in which the field data is input by using the field graphics are set in data cells. The calculation results of the data cells, such as the sum of the values in the data cells, are displayed in the summary row. The user sets in advance the type(s) of calculation(s) for the data cells in the summary row. Lines for splitting the cells from each other are called split lines. The number of columns or rows in a table can be arbitrarily set by the user. Alphabetic strings including “K” and “X” in FIG. 6 are output pictures. The output picture “K” denotes an alphabetic character and the output picture “X” denotes a numeral. The number of “Ks” and “Xs” determine the number of output characters and the number of digits, respectively. A form file may have a version designed for increasing the processing speed or achieving multiplatform operation, in addition to a standard version. Such a form file is hereinafter referred to as a general-purpose form, in contrast to a standard form for the standard version. However, the general-purpose form is restricted in its function compared with the standard form. With the standard form, the summary cells can be edited separately from the data cells to create a table. In contrast, with the general-purpose form, restrictions apply to the summary cells and the data cells. For example, the widths of the summary cells must be equal to those of the corresponding data cells, or the number of data columns must be equal to the number of summary columns. Such restrictions have heretofore caused a problem in that the user had to always be aware of whether the standard form or the general-purpose form was being used in editing a table. In addition, the user had to re-edit the table in order to convert the table from the standard form to the general-purpose form, thus requiring a lot of time and effort. According to the first embodiment, it is determined whether the form to be edited is the standard form or the general-purpose form. If the general-purpose form is to be edited, the data cells and the summary cells are edited interdependently. FIG. 7 is a flowchart showing a process of editing a table according to the first embodiment. In Step S1, the process determines whether a form is edited in the table editing mode. If the form is not edited in the table editing mode, processing of FIG. 7 ends. However, if the form is edited in the table editing mode, processing proceeds to Step S2 and the process determines whether a user instructs editing of the data cells. If it is determined that the user did not instruct editing of the data cells, processing returns to Step S1. However, if it is determined that the user instructs editing of the data cells, processing proceeds to Step S3 and the process determines whether the current form is the standard form or the general-purpose form. It is assumed that the standard form or the general-purpose form has been set in advance at the start of creation of the form or the like. For example, the standard form or the general-purpose form may be set by using a dialog box, as shown in FIG. 8. If the process determines in Step S3 that the current form is the general-purpose form, in Step S4, the process determines whether both the data cells and the summary cells must be edited by using the general-purpose form in response to an editing instruction from the user. If both the data cells and the summary cells must be edited by using the general-purpose form (for example, if the size of the data cells is to be changed), in Step S5, the data cells and the summary cells are edited interdependently in accordance with the editing instruction from the user. Processing then returns to Step S1. If the process determines in Step 4 that the data cells and the summary cells are not required to be edited interdependently (for example, if the number of output pictures in the data cells is to be changed), in Step S7, the corresponding data cells are edited. Processing then returns to Step S1. If the process determines in Step S3 that the current form is the standard form, in Step S6, the data cells are edited in accordance with the editing instruction. In Step S6, the data cells are edited whereas the summary cells are not edited interdependently with the editing of the data cells. Processing then returns to Step S1. Exemplary changes in the user interface corresponding to Steps S1 to S5 are shown in FIGS. 9 and 10. FIG. 9 is a diagram illustrating the operation of changing the width of data cells when the general-purpose form is specified. The process determines that the width of the data cells is to be changed based on a click-and-drag operation on a split line or a split point and that the data cells and the summary cells must be edited interdependently in order to meet the restrictions on the general-purpose form. In this case, the width of the summary cells is automatically changed interdependently with the change of the width of the data cells. FIG. 10 is a diagram illustrating the operation of adding data cells when the general-purpose form is specified. When the user instructs addition of data cells, the process determines that the data cells and the summary cells must be edited interdependently in order to meet the restrictions on the general-purpose form. In this case, summary cells are automatically added interdependently with the addition of the data cells. Furthermore, summary cells are automatically deleted interdependently with the deletion of the data cells. As described above, when the general-purpose form is specified, the process automatically determines in Step S4 whether both the data cells and the summary cells must be edited interdependently in response to the editing instruction from the user. Accordingly, it is not necessary for the user to be aware of whether the instructions conform to the format of the general-purpose form. Although cases where the summary cells are automatically edited interdependently with the editing of the data cells are illustrated in FIGS. 9 and 10, the data cells may be automatically edited interdependently with the editing of the summary cells. Second Embodiment The data cells and the summary cells are edited interdependently in the first embodiment. In contrast, according to a second embodiment of the present invention, a process of converting from the standard form to the general-purpose form, when the standard form is specified and the format of the data cells are set differently from the format of the summary cells is described next. In order to convert the table from the standard form to the general-purpose form, the table must meet the restrictions of the general-purpose form. According to the second embodiment, since the table is automatically converted to meet the restrictions of the general-purpose form when the table is converted from the standard form to the general-purpose form, the need for the user to manually re-edit the table is eliminated, thus lightening the burden on the user. FIG. 11 is a flowchart showing a process of converting a table according to the second embodiment. In Step S21, the process determines whether a user instructs setting of the general-purpose form. If it is determined that the user did not instruct setting of the general-purpose form, processing of FIG. 11 ends. However, if it is determined that the user instructed setting of the general-purpose form, processing proceeds to Step S22 and the process determines whether the general-purpose form includes a table. If it is determined that the general-purpose form does not include a table, processing of FIG. 11 ends. However, if it is determined that the general-purpose form includes a table, processing proceeds to Step S23 and the process determines whether the number of cells in the summary row is equal to the number of cells in each data row in the table. If it is determined that the number of cells in the summary row is equal to the number of cells in each data row in the table, in Step S27, the process automatically aligns the split lines of the summary row with the corresponding split lines of the data rows. FIG. 12 is a diagram illustrating the operation of aligning a split line of the summary row with a split line of the data rows in response to the instruction to convert into the general-purpose form when the position of the split line of the summary row is shifted from the position of the split line of the data rows. With this operation, the table can be smoothly converted from the standard form to the general-purpose form even if a user does not manually edit the table. Referring back to FIG. 11, after automatically converting the table (Step S27), processing of FIG. 11 ends. If the process determines in Step S23 that the number of cells in the summary row is not equal to the number of cells in each data row, in Step S24, for example, the process displays a dialog box as shown in FIG. 13 where the user can select the method of converting the table to the general-purpose form. In the dialog box in FIG. 13, the user can select a mode in which the number of cells in the table is manually edited, a mode in which the table is automatically converted into the general-purpose form, or a mode in which the conversion into the general-purpose form is not performed. Parameters for aligning the current table right, aligning the current table left, and so on may be set for the mode where the table is automatically converted into the general-purpose form. In Step S25, the process determines whether the user instructs automatic conversion of the table into the general-purpose form. If the process determines that the user instructs automatic conversion of the table into the general-purpose form, in Step S26, the process acquires one of the automatic-conversion parameters specified in Step S24. In Step S27, the table is automatically converted into the general-purpose form. FIGS. 14 and 15 illustrate examples of the automatic conversion. FIG. 14 illustrates an example in which the number of cells in the summary row is less than the number of cells in each data row. In this case, converting the table into the general-purpose form automatically adds a new cell to the summary row. The new cell is added to the leftmost side of the summary row when the parameter for aligning the current table right is specified, whereas the new cell is added to the rightmost side of the summary row when the parameter for aligning the current table left is specified. FIG. 15 illustrates an example in which the number of cells in the summary row is greater than the number of cells in each data row. In this case, converting the table into the general-purpose form automatically deletes cells from the summary row, so that the number of cells in the summary row becomes equal to the number of cells in each data row. Referring to FIG. 15, two right-hand cells are deleted and two left-hand cells remain when the parameter for aligning the current table left is specified, whereas the two left-hand cells are deleted and the two right-hand cells remain when the parameter for aligning the current table right is specified. The table of the standard form can be automatically converted into the table of the general-purpose form in this manner, thus lightening the burden on the user. Referring back to FIG. 11, if the process determines in Step S25 that the user does not instruct automatic conversion of the table into the general-purpose form, in Step S28, the process determines whether the user manually edits the table. If the process determines that the user does not automatically edit the table, processing of FIG. 11 ends. On the other hand, if the process determines that the user manually edits the table, in Step S29, the process displays the table editing mode and, then in Step S210, the user edits the table. Accordingly, the edit screen is smoothly displayed even when the user wants to edit the table not automatically but manually. Processing of FIG. 11 then ends. As described above, according to the present invention, it is possible to efficiently edit or convert the table in the creation or editing of a form. While the present invention has been described with reference to what are presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a form processing method, a form processing program, and a form processing apparatus for use in editing forms. 2. Description of the Related Art Heretofore, in order to output a form, data in a data file has been input into a predetermined field in a form file (standard template) indicating the layout of the form to create the output form. Such a method is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2001-283140. A graphic indicating a field to which data is input is referred to herein as a field graphic, and data in a data file is referred to herein as field data. A form including a table can be created by using such field graphics. However, there may be restrictions on the layout of fields in the form depending on the type of form (form file). Therefore, a user must be aware of the restrictions corresponding to the type of form in order to create a desired form. Such restrictions require a significant amount of time and effort of the user. | <SOH> SUMMARY OF THE INVENTION <EOH>A form processing method, a form processing program, and a form processing apparatus, which are capable of easily editing fields (particularly, fields included in a table) in a form file in the editing of a form are disclosed. According to an aspect of the present invention, a form processing method edits at least one target field in a form. The form processing method includes the steps of determining the type of the form; determining whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type of form; and editing the target field interdependently with the related field, if it is determined that the editing instruction is given to edit the target field interdependently with the related field relating to the target field. According to another aspect of the present invention, a form processing method edits at least one target field in a form. The form processing method includes the steps of determining whether an instruction is given to change the type of the form; determining whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, if the instruction is given to change the type of the form to a predetermined type of form, the data calls and the summary cell being cells included in a table in the form; and converting the table such that the position of a split line of the summary row is aligned with the position of a corresponding split line of the data row, if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, and converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row. According to another aspect of the present invention, a form processing program includes program code that causes a computer to edit at least one target field in a form. The computer code includes the steps of determining the type of the form; determining whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type of form; and editing the target field interdependently with the related field if it is determined that the editing instruction is given to edit the target field interdependently with the related field. According to another aspect of the present invention, a form processing program includes program code that causes a computer to edit at least one target field in a form. The computer code includes the steps of determining whether an instruction is given to change the type of the form; determining whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, if the instruction is given to change the type of the form to a predetermined type of form, the data calls and the summary cell being cells included in a table in the form; and converting the table such that the position of a split line of the summary row is aligned with the position of a corresponding split line of the data row, if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, and converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row. According to another aspect of the present invention, a form processing apparatus is configured to edit at least one target field in a form. The form processing apparatus includes a form determining unit configured to determining the type of the form; a determining unit configured to determine whether an editing instruction is given to edit the target field interdependently with a related field relating to the target field, if the type of the form is a predetermined type of form; and an editing unit for editing the target field interdependently with the related field, if it is determined that the editing instruction is given to edit the target field interdependently with the related field relating to the target field. According to another aspect of the present invention, a form processing apparatus is configured to edit at least one target field in a form. The form processing apparatus includes a form determining unit configured to determine whether an instruction is given to change the type of the form; a number-of-cells determining unit configured to determine whether the number of data cells in each data row to which field data is input is equal to the number of summary cells in a summary row where the field data input in the data cells is summed, if the instruction is given to change the type of the form to a predetermined type of form, the data calls and the summary cell being cells included in a table in the form; and a converting unit configured to convert the table such that the position of a split line of the summary row is aligned with the position of a corresponding split line of the data row, if it is determined that the number of data cells in the data row is equal to the number of summary cells in the summary row, and for converting the table such that the number of summary cells in the summary row is matched with the number of data cells in the data row and such that the position of the split line of the summary row is aligned with the position of the corresponding split line of the data row, if it is determined that the number of data cells in the data row is not equal to the number of summary cells in the summary row. According to the present invention, it is possible for a user to perform editing without being aware of whether his editing instructions conform to the format (restrictions) corresponding to the type of a form, thus allowing the user to efficiently editing the form. Further features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings. | 20040712 | 20070918 | 20050120 | 71280.0 | 0 | QUELER, ADAM M | FORM PROCESSING METHOD, FORM PROCESSING PROGRAM, AND FORM PROCESSING APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,889,686 | ACCEPTED | Thin film infrared transparent conductor | A cadmium oxide (CdO) film doped with any of the Group III elements is substantially transparent to radiation between about 0.7 μm and 12 μm. A film made according to the invention having a sheet resistance of <600 Ω/□ will also have exceptionally low optical absorption throughout the IR range. The film is suitably employed as transparent, electrically conductive electrodes, and can be used in devices such as liquid crystal cells for beam steering, spatial light modulators, optical switches for fiber optical communications, switchable and/or tunable polarization modification components, and top transparent electrodes for SWIR (1.3 and 1.5 μm) VCSELs. | 1. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 4% at wavelengths of 1-2 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 2. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 10% at wavelengths of 3-5 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 3. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 20% at wavelengths of 8-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 4. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 1% at wavelengths of 1-2 μm, a sheet resistance of 200 Ω/□ or less, and a resistivity of less than 5×10−4 Ω-cm. 5. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 3% at wavelengths of 3-5 μm, a sheet resistance of 200 Ω/□ or less, and a resistivity of less than 5×10−4 Ω-cm. 6. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 4% at wavelengths of 8-12 μm, a sheet resistance of 200 Ω/□ or less, and a resistivity of less than 5×10−4 Ω-cm. 7. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 0.2% at a wavelength of 1.3 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 8. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 0.5% at a wavelength of 1.5 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 9. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 0.7% at wavelengths of 1-2 μm, a sheet resistance of 200 Ω/□ or less, and a resistivity of less than 5×10−4 Ω-cm. 10. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 2.0% at wavelengths of 1-2 μm, a sheet resistance of 20 Ω/□ or less, and a resistivity of less than 5×10−4 Ω-cm. 11. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 25% at wavelengths of 3-51 μm, a sheet resistance of 11 Ω/□ or less, and a resistivity of less than 5×10−4 Ω-cm. 12. The film of claim 11, wherein said film provides RF or EMI shielding. 13. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than about 40% at wavelengths of 8-12 μm, a sheet resistance of 21 Ω/□ or less, and a resistivity of less than 5×10−4 i-cm. 14. The film of claim 13, wherein said film provides RF or EMI shielding. 15. An electrically conductive, infrared transparent film comprising CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), the doped film having an absorption loss of less than 20% at wavelengths of 1-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 16. The film of claim 15, wherein the concentration of said dopant is between 0.05% and 6% by weight. 17. The film of claim 15, wherein said film comprises CdO doped with indium. 18. The film of claim 15, further comprising a substrate on which said film is grown, said film including a transition layer at the interface between the grown film and substrate, said transition layer being 100-200 Å thick. 19. The film of claim 15, wherein said thin film is formed by means of a vapor deposition process wherein sufficient energy is imparted to the vaporized material to activate the dopant species. 20. The film of claim 19, wherein said thin film is formed by means of pulsed laser deposition (PLD). 21. A method of forming a thin film conductor that is substantially transparent at infrared wavelengths, comprising: preparing a mixture of materials to be vaporized, said materials comprising CdO and at least one dopant element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant); placing a substrate in a substrate holder in a vacuum chamber; placing said mixture in a target holder in said vacuum chamber; and focusing a laser on said target to vaporize said mixture such that said dopant is activated and said mixture condenses on said substrate via pulsed laser deposition to form a thin film. 22. The method of claim 21, wherein said thin film has an absorption loss of less than 20% at wavelengths of 1-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 23. The method of claim 21, wherein said laser is either a Kr:F, fluorine, ArF, or XeCl excimer laser, or a Q-switched Nd:YAG laser with frequency quadrupler that delivers high energy pulsed UV output. 24. The method of claim 21, wherein said mixture contains from about 0.5% to about 6% by weight of said dopant. 25. The method of claim 21, wherein said mixture contains from about 0.05% to about 6% by weight of said dopant. 26. The method of claim 21, further comprising the step of providing hydrogen gas or CH4 in said chamber while said mixture is vaporized and condensing. 27. The method of claim 26, wherein the substrate temperature while said mixture is vaporized and condensing is less than 200° C., and said resulting thin film has an absorption loss of less than 20% at wavelengths of 1-12 μm, and a resistivity of less than 5×10−4 Ω-cm. 28. The method of claim 26, wherein the substrate temperature while said mixture is vaporized and condensing is at room temperature, and said resulting thin film has an absorption loss of less than 20% at wavelengths of 1-12 μm, and a resistivity of less than 5×10−4 Ω-cm. 29. A device for modifying the optical phase of incident light, comprising: a first substrate layer that is substantially transparent to the light incident thereon, said first substrate having a first and second surface; a first optically transparent, electrically conductive layer on the second surface of the first substrate, said first electrically conductive layer compromising a layer of CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant); a second substrate layer having a first and second surface; a second electrically conductive layer on the second surface of the second substrate; and a layer of liquid crystal material disposed between the second surfaces of said first and second substrate layers. 30. The device of claim 29, wherein said layer of doped CdO has an absorption loss of less than 20% at wavelengths of 1-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 31. The device of claim 29, wherein said liquid crystal layer is ordered in the nematic state in the absence of having a voltage applied between first and second conductive layers. 32. The device of claim 29, wherein said liquid crystal layer is ordered in the twisted nematic state in the absence of having a voltage applied between first and second conductive layers. 33. The device of claim 29, wherein said liquid crystal layer is ordered in the cholesteric phase in the absence of having a voltage applied between first and second conductive layers. 34. The device of claim 29, wherein the second substrate is substantially transparent to light incident on the device. 35. The device of claim 29, wherein said second electrically conductive layer comprises CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), has an absorption loss of less than 20% at wavelengths of 1-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 36. A top emitting vertical cavity surface emitting laser (VCSEL), comprising: a substrate; a bottom dielectric bragg reflector (DBR) on said substrate; an electrical contact contacting a portion of said bottom DBR; a top dielectric bragg reflector which is above and separated from said bottom DBR such that said top and bottom DBRs act as front and rear mirrors to define an optical cavity; and an optically transparent, electrically conductive layer on said top DBR which provides an electrical contact to said top DBR, said electrically conductive layer compromising a layer of CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant). 37. The VCSEL of claim 36, wherein said layer of doped CdO has an absorption loss of less than 20% at wavelengths of 1-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 38. A ferroelectric device, comprising: a ceramic or single crystal slab having top and bottom sides; a first optically transparent, electrically conductive layer on the top side of said slab; and a second optically transparent, electrically conductive layer on the bottom side of said slab, said first and second optically transparent, electrically conductive layers each compromising a layer of CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), said first and second optically transparent, electrically conductive layers forming first and second electrodes for “poling” the slab material and modulating its properties. 39. The ferroelectric device of claim 38, wherein each of said layers of doped CdO have an absorption loss of less than 20% at wavelengths of 1-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 40. A Pockels' cell, comprising: a first optically transparent, electrically conductive layer; a second optically transparent, electrically conductive layer; a material whose birefringence changes, said material sandwiched between said first and second electrically conductive layers, said first and second optically transparent, electrically conductive layers each compromising a layer of CdO doped with at least one element from the group consisting of boron, aluminum, gallium, indium, thallium, bismuth, fluorine, or hydrogen (as a co-dopant), said first and second optically transparent, electrically conductive layers forming first and second electrodes. 41. The Pockels' cell of claim 40, wherein each of said layers of doped CdO have an absorption loss of less than 20% at wavelengths of 1-12 μm, a sheet resistance of <600 Ω/□, and a resistivity of less than 5×10−4 Ω-cm. 42. The Pockels' cell of claim 40, wherein said material whose birefringence changes is solid. 43. The Pockels' cell of claim 40, wherein said material whose birefringence changes is liquid, further comprising first and second window layers arranged to confine said liquid, said first and second electrically conductive layers applied to the liquid side of said first and second window layers, respectively. | This application claims the benefit of U.S. Provisional Application Ser. No. 60/282,337 filed Apr. 6, 2001, and is a continuation-in-part of Ser. No. 10/112,465 filed Mar. 29, 2002. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to transparent conductive thin films for use in electro-optical devices. 2. Description of the Related Art Many electro-optical devices operating in the infrared (generally, wavelengths of ˜0.7 μm to ˜14 μm) require conductive thin films that are extremely transparent. Such devices include liquid crystal cells for beam steering, spatial light modulators, and optical switches for fiber optic communications, switchable and/or tunable polarization modification components, and long wavelength vertical cavity surface emitting lasers (VCSELs). Conventional transparent conductive oxides such as indium tin oxide (ITO), zinc oxide (ZnO), and tin oxide (SnO2) cannot fulfill the requirements of these applications. These materials are mostly transmissive in the visible; however, transmission in the infrared drops due to free carrier absorption. The transmission values versus wavelength for an ITO film on a glass substrate are shown in FIG. 4. For ITO films with a sheet resistance of about 140 Ω/□ the transmission is about 98% at 1.3 μm and about 97% at 1.5 μm; 1.3 μm and 1.5 μm are critical values for fiber-optic communication and long wavelength VCSEL applications. Other possible optically transparent conductive materials such as doped semiconductor wafers or epitaxial layers (Si, Ge, GaAs, InP doped) have limited utility because they do not cover the entire spectral range, have a limited size, and are expensive. U.S. Pat. No. 6,458,637, issued Oct. 1, 2002 to Jeffrey T. Cheung, directed to transparent and conductive zinc oxide films, describes the introduction of hydrogen or a hydrocarbon gas (in addition to oxygen) into the vacuum chamber during growth of the film using pulsed laser deposition from a 2.0 atomic wt. % gallium-doped ZnO target. This approach incorporated hydrogen atoms into the ZnO lattice during growth and activates them to behave as electron donors so that a low electrical resistivity film (0.9-3×10−4 Ω-cm) could be grown at low temperature. The process was found to work only when gallium was also present in the lattice. The resultant films, with or without doping, had a transmissivity of no more then about 90% at wavelengths of 0.35 to 2.0 μm. Cadmium oxide (CdO) films doped with indium (CdO:In) have been prepared in the past for flat-panel displays and solar cells which require high transparency to visible light. However, these films are well known for their toxicity, and therefore the prior art has steered away from developing such films. Minami et al. reports that CdO:In films have been prepared with a resistivity of the order of 10−5 Ω-cm for flat-panel displays and solar cells, but he states that they are of no practical use because of Cd toxicity. (Minami, Tadatsugu, “New n-Type Transparent Conducting Oxides”, Transparent Conducting Oxides, Volume 25, No. 8, August 2000, p.38). Further, because these films have a yellow color, which differentiates them from prior art transparent films that are clear in appearance, one skilled in the art would be steered away from using these films for any applications requiring transparent films. Undoped CdO has been prepared by sputtering, MOCVD, and spray pyrolysis (Murthy, L. C. S. & Rao, K. S. R. K., “Thickness Dependent Electric Properties of CdO Thin Films Prepared by Spray Pyrolysis Method,” Bulletin of Material Science, Vol. 22, No. 6, pp.953-957 (October 1999); Subramarnyam, T. K et al., “Preparation and Characterization of CdO Films Deposited by DC Magnetron Reactive Sputtering”, Materials Letter, Vol. 35, pp.214-220, (May 1998); Baranov, A M et al., “Investigation of the Properties of CdO Films”, Tech. Phys. Ltr, 23, (10) pp.805-806 (October 1997)). Transmission no greater then about 85% has been reported in the wavelength range of 0.6-1.6 μm. Representative data, doping and method of fabrication for these references, along with additional references reporting on CdO films, are listed in Table 1 below. TABLE 1 LITERATURE REPORTING ON CDO FILMS Thick. Growth Resistivity T % & Approach Dopant Substrate Å Temp Ohm-cm range Pulsed Laser Intrinsic* Glass R. T. + post >10−3 60-90% @ Sputtering1 annealing 0.5-2.0 μm Activated Reactive Intrinsic* Glass 350 4 × 10−4 70-80% @ Evaporation2 0.5-.85 μm Solution Growth3 Intrinsic* Glass 2000 R. T. + post 2-5 × 10−4 75-85% @ annealing 0.5-0.9 μm Ion beam Intrinsic* Glass 5000 50-70 C. 5 × 10−3 70-80% @ sputtering4 0.5-.85 μm** Spray pyrolysis4 Intrinsic* Glass 5000 180-225 2-5 × 10−3 70-80% @ 0.5-.85 μm** DC reactive Undoped Glass R. T. + post 102-10−3 40-85%@ sputtering5 annealing 0.5-.90 μm 6sputtering Indium 10−5 Spray Pyrolysis7 Undoped DC Magnetron Undoped Glass 5-49 85% @ Reactive 0.6-1.6 μm Sputtering8,9 Magnetron Undoped >7 × 10−4 60-70% @ Sputtering10 0.5-0.9 μm Spray Pyrolysis11 Fluorine 80-90%@ 0.4-0.7 μm; <80% @ >0.7-1.2 μm Low Press. CVD12 Undoped Glass 500-800 2 × 10−3 *Intrinsic dopant means that donors in the materials are due to defects not impurities **Measured against glass slide as reference 1Shaganov, II, et al., “Obtaining transparent oxide conducting coatings by pulsed laser sputtering” Sov. J. Opt. Technol. 48(5), p 280-282 (May, 1981) 2Pahtak, Girish et al, “Deposition and properties of cadmium oxide films by activated reactive evaporation”, Thin Solid Films, 245, p17-26 (1994) 3Varkey, AJ et al, “Transparent conducting cadmium oxide thin films prepared by a solution growth technique”, Thin Solid Films, 239, p211-213 (1994) 4Chu, TL et al, “Degenerate Cadmium Oxide films for electronic devices”, J. Electronic Materials , 19, p1003- (1990) 5Tanaka, K et al “Electrical and optical properties of sputtered CdO films”, Japanese J. of Appl. Phys., 8(6), p681-691 (June 1969) 6Minami, Tadatsugu, “New n-Type Transparent Conducting Oxides”, Transparent Conducting Oxides, 25, (8), p38-44 (August 2000) 7Murthy, L. C. S. et al., “Thickness Dependent Electric Properties of CdO Thin Films Prepared by Spray Pyrolysis Method”, Bulletin of Material Science, 22, (6), pp953-7 (Oct. 1999) 8Subramarnyam, T. K et al, “Preparation and Characterization of CdO Films Deposited by DC Magnetron Reactive Sputtering”, Materials Letter, 35, pp 214-220, (May 1998) 9Subramarnyam, T. K et al, “Influence of Oxygen Pressure on the Structural and Optical Properties of DC Magnetron Reactive Sputtered Cadmium Oxide”, Physica Scripta, 57, p317 - (1998) 10Baranov, AM. et al, “Investigation of the Properties of CdO Films”, Tech. Phys. Ltr, 23, (10) pp 805-806 (October 1997) 11Ferro, R et al “F-Doped CdO Thin Films Deposited by Spray Pyrolysis”, PMS. State. Sol. (a) 177, P477-483 (2000) 12Coutts, TJ et al, “Search for improved transparent and conducting oxides: A fundamental investigation of CdO, Cd2SnO4, and Zn2SnO4”, J Vac. Sci. Tech., A18, (6), p2646-2660, (Nov/Dec 2000) There is a need for films with lower resistivity and low optical absorption at wavelengths that extend from the short-wavelength infrared (SWIR) (1-2 μm) through the mid-wavelength infrared (MWIR) (3-5 μm) and possibly into the long wavelength infrared (LWIR) (8-12 μm). As an example, devices operating in the fiber telecommunication bands at 1.3 or 1.5 μm require an optical transmission of at least 99%. SUMMARY OF THE INVENTION A doped cadmium oxide (CdO) film with high optical transmission and suitable electrical conductivity has been developed for use in applications requiring conductive, infrared transparent films. Suitable dopants for the film include any of the Group III elements (i.e. boron, aluminum, gallium, indium or thallium), bismuth, fluorine, and hydrogen (as a co-dopant) if properly processed. The new doped film is substantially transparent to infrared radiation in the range of between about 0.7 μm and 14 μm. Films made according to the invention have a sheet resistance of <600 Ω/□ (typically ≦200 Ω/□), and have exceptionally low optical absorption throughout the IR range: less than 4% (typically <1%) in the SWIR, less than 10% (typically <3%) in the MWIR, and less than 20% (typically <4%) in the LWIR. In addition, a film per the present invention having a sheet resistance of <600 Ω/□ (typically ≦200 Ω/□) has an absorption loss of about ≦0.2% at 1.3 μm and ≦0.5% at 1.5 μm. Films made according to the invention have a resistivity of less than 5×10−4 Ω-cm. Low resistivity films per the present invention can be prepared at much lower temperatures (20° C.) by co-doping with hydrogen. There are numerous applications for such films functioning as transparent, electrically conductive electrodes, including (but not limited to) liquid crystal cells for beam steering, spatial light modulators, optical switches for fiber optical communications, switchable and/or tunable polarization modification components, top transparent electrodes for SWIR (1.3 and 1.51 μm) VCSELs, Pockels' cells, MEMs devices, and ferroelectric cells. Other applications include radio frequency shielding of windows that can transmit infrared radiation. BRIEF DESCRIPTION OF THE DRAWINGS These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings, in which: FIG. 1 is a plot showing the spectral transmission data for a CdO:In film per the present invention compared to the transmission of the substrate upon which it is deposited. FIG. 2 shows the transmission of the film of FIG. 1 normalized by the transmission of an uncoated substrate for the range of 0.5 to 3.0 μm. FIG. 3a is a plot showing transmission versus wavelength for a CdO:In film per the present invention on a MgO substrate for wavelengths from 2.5 to 10 μm. FIG. 3b is a plot showing the transmission of the film of FIG. 3a, normalized by the transmission of an uncoated substrate. FIG. 4 is a plot comparing the transmission of a CdO:In film per the present invention with a prior art ITO film of comparable sheet resistance for w avelengths from 0.5 to 2.0 μm. FIG. 5 is a combination of FIGS. 3b and 4 for wavelengths of 0.5 to 10 μm. FIG. 6 shows the x-ray diffraction pattern for a CdO:In film per the present invention. FIG. 7 is a graph comparing the refractive index of the present CdO:In film with that of an ITO film. FIG. 8 is a graph showing the resistivity of a CdO:In film and a CdO:In film co-doped with hydrogen, formed at various temperatures. FIG. 9 is a graph comparing the optical transmission of In and In:H co-doped CdO films per the present invention. FIG. 10 is a graph showing real refractive indices versus wavelength for CdO:In films per the present invention which have different concentrations of indium. FIG. 11 is a graph showing imaginary refractive indices versus wavelength for CdO:In films per the present invention which have different concentrations of indium. FIG. 12 is a graph showing absorption coefficients versus wavelength for CdO:In films per the present invention which have various resistivities. FIG. 13 is a graph showing transmission and reflectance versus wavelength for one embodiment of a CdO:In film per the present invention. FIG. 14 is a graph showing transmission and reflectance versus wavelength for another embodiment of a CdO:In film per the present invention. FIG. 15 is a graph showing resistivity versus thickness for a CdO:In film per the present invention. FIG. 16 is a cross-sectional view of an embodiment of a liquid-crystal-based device incorporating a CdO:In film per the present invention. FIG. 17a is a cross-sectional view of a prior art embodiment of a VCSEL device. FIG. 17b is a cross-sectional view of an embodiment of a VCSEL device incorporating a CdO:In film per the present invention. FIG. 18a is a cross-sectional view of a prior art embodiment of a ferroelectric device. FIG. 18b is a cross-sectional view of an embodiment of a ferroelectric device incorporating a CdO:In film per the present invention. FIG. 19a is a cross-sectional view of an embodiment of a Pockels' cell device incorporating a CdO:In film per the present invention. FIG. 19b is a cross-sectional view of another embodiment of a Pockels' cell device incorporating a CdO:In film per the present invention. DETAILED DESCRIPTION OF THE INVENTION A doped Cadmium Oxide (CdO) film has been developed for use primarily in applications requiring conductive, infrared transparent films. Suitable dopants for the film include any of the Group III elements (i.e. boron, aluminum, gallium, indium or thallium), bismuth, fluorine, and hydrogen (as a co-dopant). In addition, hydrogen and a group III element such as indium can be used simultaneously as co-dopants to lower the growth temperature of transparent and electrically conductive films. These dopants are believed to increase the electron concentration of CdO, thus making it more conductive. There are numerous applications for the film, including: 1) transparent conductive electrodes for liquid crystal cells used in beam steering, spatial light modulators, and optical switches, particularly optical switches operating in the infrared spectral range up to 14 μm wavelength 2) Improved shielding from Electromagnetic (EM) or Radio Frequency (RF) interference 3) Top electrodes for SWIR VCSELs 4) Pockels' cells 5) MEMs devices 6) Transparent conductive electrodes for devices based on ferroelectric materials, such as non-volatile memory and electro-optic devices While not requiring the transparent properties of the CdO film, the present films can also be used in electrodes for piezoelectric devices. The terms “sheet resistance” and “resistivity” are used herein; they are defined as follows. Resistance (R) is electrical resistance measured between two contacts on an electrically conductive material of any shape and thickness. It is not a quantitative description of material property. The unit of resistance is the ohm (Ω). Resistivity (ρ), also known as specific resistance, is the resistance measured across the opposite faces of a 1 cm×1 cm×1 cm cubic shaped material. The unit of resistivity is the Ω-cm. This quantity depends only on the fundamental property of a thin film material; i.e., it does not depend on its thickness. However, as will be discussed below, sometimes the resistivity of a thin film is different near the initial growth interface. Sheet resistance (Rs) is a quantity that is often used to describe the conducting thin film or layers in a device (e.g., the RF shield and electrodes for liquid crystal and ferroelectric devices). It is expressed in units of Ω/□ and is dependent on thickness “d”. It is related to resistivity (ρ) by the following relationship: ρ=Rs×d, with d specified in cm. Films made according to the invention have a sheet resistance of <600 Ω/□(typically ≦200 Ω/□), and have exceptionally low optical absorption throughout the IR range: less than 4% (typically <1%) in the SWIR, less than 10% (typically <3%) in the MWIR, and less than 20% (typically <4%) in the LWIR. In addition, a film per the present invention having a sheet resistance of <600 Ω/□ (typically ≦200 Ω/□) has an absorption loss of about ≦0.2% at 1.3 μm and ≦0.5% at 1.5 μm. Films made according to the invention have a resistivity of less than 5×10−4 W-cm. The film can be grown on any suitable substrate such as MgO, glass, quartz, sapphire, silicon, AION, spinel, ZnSe, ZnS, GaAs, Ge, etc. Many methods are known for growing Group III element doped CdO films, including metal organic chemical vapor deposition (MOCVD), spray pyrolysis, sol-gel, vapor transport, hot wall epitaxy, close-space vapor transport, plasma-enhanced chemical vapor deposition (PECVD), sputtering, activated reactive evaporation, ion-assisted deposition, and pulsed electron-beam evaporation (see Handbook of Deposition Technologies For Films and Coatings, Second Edition, Noyes Publications, Bunshah, R. F. 1994). However, to obtain the combination of low electrical resistivity and high optical transmissivity described herein, the present invention requires that the film be formed using a method which “activates” the dopants. A preferred method is pulsed laser deposition (PLD) since it allows for accurate control of the film composition and thickness, and facilitates the activation of dopants. This method is described in great detail in “Pulsed Laser Deposition of Thin Films”, Chrisey, 1994. Specifically, the experimental set up comprises a target holder and a substrate holder housed in a vacuum chamber. A well-blended mixture of the material to be vaporized and condensed on the substrate is placed in the target holder. A high-power laser used as an external energy source is focused on the target to vaporize the mixture in a controlled manner. Various optical components are used to focus and raster the laser beam over the target surface. (see “Pulsed Laser Deposition of Thin Films”, Chrisey, 1994, p. 3). Absorption characteristics of the material to be evaporated determine the laser wavelength to be used. Pulse width, repetition rate, and pulse intensity are selected for specific applications. (see Bunshah, pg. 167). The thickness of the film can be controlled by varying the pulse repetition rate and distance of the target. The PLD process has been used to produce films having a thickness between 100-4000 Å. The composition of the grown film is substantially the same as that of the target composition. For preparation of the CdO film incorporating features of the invention, a preferred composition contains from about 0.5%, to about 6% by weight of the dopant. However, films with suitable properties can be obtained with indium concentrations as low as 0.05%(atomic weight). Films with 0.5-6.0% indium exhibit excellent optical properties up to a wavelength of about 2.0 μm, beyond which the free carrier absorption becomes dominant. By reducing the doping concentration to about 0.05%(atomic wt.) of indium, optical transmission is improved at longer wavelengths. The films can be grown at temperatures from about 20° C. to about 425° C. The substrate temperature affects the quality of the film with higher temperature producing a film with higher electrical conductivity and optical transparency in the infrared and visible range. An exemplary procedure for growth of a doped CdO film per the present invention is set forth in the example below. EXAMPLE 1 Growth of Indium Doped CdO (“CdO:In”) by PLD A ceramic target comprising In2O3 and CdO was placed in the target holder of the PLD chamber about 10 inches away from an MgO substrate. The target was prepared by mixing 1% by weight In2O3 powder with 99% by weight CdO powder in a jar, filling the jar with a quantity of methanol approximately equal in volume to the CdO/In2O3 mixture to form a slurry, and adding a like volume of ceramic beads (approximately 1 cm in diameter) to the mixture. The mixture was then “rolled” for 24 hours, the process being known as “ball milling”. The methanol was then evaporated from the mixture and the beads were sifted out. The remaining powder was pressed into a cylindrical shape and sintered in a high temperature furnace (about 1100° C.) to form a ceramic target. The target was then placed in a vacuum chamber having an O2 partial pressure of approximately 5-50 millitorr and the temperature of the substrate was raised to 440° C. The target was irradiated using a Kr:F excimer laser beam having a wavelength of 248 nm with a pulse energy of 390 mJ/pulse at a frequency of 5 pulses/sec. The energy delivered by the laser was 1 J/cm2 with a pulse duration of 32 ns. Other excimer laser types, such as fluorine, ArF, and XeCl, or a Q-switched Nd:YAG laser with frequency quadrupler that delivers high energy pulsed UV output, might also be used. Electrical conductivity was determined using a four-point probe measurement. The CdO:In film was found to have a sheet resistance of 112 Ω/□ and exceptionally high transmission as shown in FIG. 1-5. The transmission of the film shown in FIG. 2 was determined by measuring the transmission of the substrate and dividing the combined transmission measured for the film and substrate together by the transmission of the substrate alone (see FIG. 1). FIGS. 3a and 3b are plots showing transmission versus wavelength for the CdO:In film for a portion of the IR range. The upper curve of FIG. 3a shows the transparency of the MgO substrate without the film, and the lower curve of FIG. 3a shows the transparency of the film and substrate combination. FIG. 3b shows the film transmission obtained by dividing the transmission of the film and substrate combination by the transmission of an uncoated substrate. FIGS. 3a and 3b shows transmission for wavelengths between 2.5 to 10 μm. As can be seen, the doped CdO film is nearly 100% transparent at the lower wavelengths, and still around 80% transparent at 10 μm. At the longer wavelengths in this range, most of the transmission is lost to reflection and not to absorption. In FIG. 4, the transmission of the CdO:In film is compared to a prior art ITO film (on a glass substrate). FIG. 5 shows FIGS. 3b and 4 combined. Both films have a comparably low sheet resistance (112 Ω/□ for the CdO:In film, and 141 Ω/□ for the ITO film). However, the transmission for the ITO film is significantly less than the transmission for the CdO:In film. As can be seen from the figures, the transmission for the ITO film peaks at about 99% at approximately 1.0 μm but then drops significantly for light of longer wavelength. Note that where transmission exceeds 100%, the film is acting as an antireflective (AR) coating. In contrast, the transmission of the CdO:In films remains constant at around 100% throughout the 0.5 to 2.0 μm range. In addition, transmissivity for the CdO:In film remains significantly high for wavelengths up to 10 μm. (The oscillations in the transmission values shown in the figures such as FIG. 5 above about 2 μm are caused by optical interference between the front and back of the substrate). Of particular significance is the high transmission values for the CdO:In films obtained at 1.3 and 1.5 μm, which are bands used in fiber optic communication systems. FIG. 6 is a plot showing X-ray diffraction data for a CdO:In film prepared using the process described above. The material is crystalline and has the same x-ray peaks as an undoped CdO film with a (200) crystalline orientation. An alternative method of contrasting indium-doped CdO films with prior known conductive films is to compare the real refractive index (n) and the imaginary refractive index (k) of both. The complex refractive index ({overscore (n)}) is the sum of the real refractive index, n (the real part of the complex refractive index), and the imaginary part of the complex refractive index, which is the extinction coefficient, k, according to the formula {overscore (n)}=n+ik. The absorption coefficient, α, is obtained from the following relationship: T=I/I0=e−αd Where α4=πk/λ, λ=wavelength, d=thickness of the film, and I/Io=light incident/light transmitted. FIG. 7 shows the real and imaginary refractive indices, as measured by variable angle spectroscopic ellipsometry, for 2% indium-doped CdO and ITO films. At a preferred operating wavelength of 1.5 μm, the real refractive index of the doped CdO film is about 4 times that of the ITO film (1.3 vs. 0.33). In contrast, the imaginary refractive index (k), which allows comparison with performance normalized to eliminate variables such as thickness, shows a value 18 times less (0.05 vs. 0.9) for the doped CdO film. Hydrogen doping or co-doping, accomplished by adding H2 or CH4 in the chamber atmosphere during film production, allows growth of low resistivity and highly transparent films such as described herein, at lower temperatures (approximately 200° C. and lower). FIG. 8 shows the electrical resistivity of CdO films grown under different temperature and two different doping conditions. Films with an indium dopant were grown using pulsed laser deposition in 15 mTorr of oxygen. It appears that film properties are not sensitive to these levels as long as it is controlled within a range from 5 mTorr to 50 mTorr. A CdO target containing 2% (atomic wt.) of indium was used. The electrical resistivity of the resultant films increases with a decrease in growth temperature. However, when 20 mTorr of hydrogen gas or CH4 was introduced into the vacuum chamber during growth, a much lower resistivity film was produced at a lower growth temperature. For example, the resistivity of a film grown at 175° C. was lowered by one order of magnitude from 5.5×10−4 Ω-cm to 5×10-5 Ω-cm by adding hydrogen gas or CH4 during growth. The resistivity of a film grown at room temperature in the presence of hydrogen or CH4 is 1×10−4 Ω-cm, which is lower than any other known transparent conducting films grown at the same temperature. FIG. 9 compares the optical transmission of two CdO films. One film is doped with 2% Indium and grown at 475° C. The other film is CdO doped with hydrogen-indium grown at 20° C. The electrical resistivities of the two films are quite similar (6.5×10−Ω-cm for the indium 475° C. film, and 1.1×10−4 Ω-cm for the In:H 20° C. film). While the co-doped film grown at 20° C. shows more optical loss in the spectral range beyond 1.1 μm, between 0.5 and 1.1 μm the difference between the two films is negligible. This data demonstrates that co-doping with hydrogen provides the capability of producing low resistivity films at much lower temperatures. These films may have a slight, but acceptable, optical loss at wavelengths greater than 1.1 microns. Gallium doped CdO has similar properties to the Indium doped CdO. Other Group III elements should provide similar properties, as should bismuth and fluorine. FIG. 10 shows the real refractive indices for six different concentrations of indium, at wavelengths of from about 0.45 μm to about 5.5 μm. As the indium concentration is increased, the dispersion shifts toward longer wavelengths. For comparison, FIG. 11 shows the imaginary refractive index, k, for films with the same indium concentrations. As the indium concentration is decreased, the optical loss edge shifts toward longer wavelengths. This suggests that the useful spectral range also shifts to higher wavelengths with a decrease in indium concentration. As indicated above, a second important property of the infrared transparent doped CdO films is the resistivity of the films. While an undoped CdO film prepared by this method will have a resistivity of about 1.45×10−3 Ω-cm, a significant reduction of resistivity to about 5×10−4 Ω-cm can be obtained by adding as little as 0.05% indium, and this can be further reduced to about 0.5×10−4 Ω-cm by increasing the dopant concentration to 2.0%. Another basis for comparison of various optical materials is the absorption coefficient, α, which is defined above. The absorption coefficient is a measure of how well a material absorbs light of a certain wavelength. A graph plotting absorption coefficient vs. wavelength for films with six different resistivities is shown in FIG. 12. As can be readily seen, absorption increases with increasing doping levels. Indium-doped CdO films deposited by PLD show electrical and optical properties superior to those grown by other techniques previously reported. The following list tabulates the properties of films made in accordance with the present invention, as might be used in various types of devices. Absorption loss (best value) of other transparent conductive materials and CdO films grown by other techniques with the same sheet resistance are listed in the parenthesis for comparison. Sheet Spectral Wavelength Resistivity resistance Absorption region (μm) (Ω-cm) (Ω/□) loss SWIR 1-2 <5 × 10−4 ≦200 <0.7% (4%) SWIR 1-2 <5 × 10−4 ≦20 <2.0% (70-80%) MWIR 3-5 <5 × 10−4 ≦11 <10-25% (>40%) LWIR 8-12 <5 × 10−4 ≦21 <15-40% FIGS. 13 and 14 show the transmission of two films used as IR transparent RF shields. These films are incorporated into an AR coating to minimize the reflective loss; an AR coating has also been added to the backside of the substrates. The coating designs were optimized for operation in the 3-5 μm wavelength range (FIG. 13) and the 8-12 μm wavelength range (FIG. 14). Absorption losses in these ranges are <25% and <40% for the 3-5 μm and 8-12 μm spectral ranges, respectively, with sheet resistances of 11 and 21 Ω/□, respectively; the films in FIGS. 13 and 14 have thicknesses of about 1000 Å and 600 Å, respectively. FIG. 13 also shows the transmission of the uncoated sapphire substrate. Designs with higher sheet resistances would have proportionally less absorption loss. Other traditional transparent conductive films, such as SnO2, ITO, ZnO, and their combinations, with comparable sheet resistances, are more absorbing at these wavelengths. PLD not only produces CdO films with high activation of the dopants (i.e. indium or other elements) to increase its electrical conductivity, it also significantly improves the film's structural quality. One example is the present film's exceptionally thin transition layer (sometimes referred to as a “dead layer”) at the interface between the grown film and substrate. A dead layer has very poor quality, with low electron mobility and high electrical resistivity. A thick dead layer will therefore increase a film's optical loss without contributing to its electrical conducting characteristics. However, for the present film, the combination of PLD and doped CdO results in a dead layer that is only approximately 100-200 Å thick (see FIG. 15). Due to the dead layer's exceptional thinness, it has little effect on the film's optical absorption characteristics. For films having higher sheet resistances, a thin dead layer is critical to achieving the properties listed above. One application of the doped CdO films is for transparent conductive electrodes for liquid crystal cells used in optical beam steering, spatial light modulators, and optical switches operating in the SWIR and MWIR ranges. A first embodiment of a device incorporating features of the invention, shown in FIG. 16, comprises a multilayer structure 500 which has a first transparent substrate 502, a liquid crystal layer 504 sandwiched between the first substrate 502 and a second substrate 508 which may also be transparent. A first electrode layer 510 is positioned between second substrate and liquid crystal layer 504, and a second electrode layer 514, a transparent doped CdO film as described herein, is positioned between first substrate 502 and liquid crystal layer 504. Other thin film layers, such as index matching or alignment layers, may also be located between the substrates. The liquid crystal layer 504 is preferably ordered in the nematic state in the absence of having a voltage applied between the electrode layers 510 and 514. It may alternatively be ordered in a twisted nematic state or cholesteric phase. A device so arranged can be used as a spatial light modulator, a beam steering device, or an optical switch. Devices fabricated using prior art conductive, transparent electrodes are limited to use with wavelengths of <μm. By replacing the prior art electrode materials with doped CdO in accordance with the present invention, the device can now be used in the SWIR and MWIR ranges and have acceptable absorption losses. In certain applications, conductive transparent films of doped CdO as described herein can be used to prevent the transmission of radio frequency interference from optical systems. In this application, the film is coated onto a transparent window surface. The infrared signal is transmitted while longer wavelength radio frequency signals (>10 MHz, e.g.) are reflected as the result of the conductivity of the film. VCSELs (Vertical Cavity Surface Emitting Lasers) are a class of solid-state laser that can be fabricated on a semiconductor wafer by batch processing to produce a dense two-dimensional array of lasers whose optical outputs are perpendicular to the substrate. These devices are small with low power consumption, fast, and vital to optical communication systems. Schematic cross sectional views of a prior art “top emitting VCSEL” and a top emitting VCSEL which employs a film in accordance with the present invention are shown in FIGS. 17a and 17b, respectively. The entire device is fabricated from a multiple layered material structure grown on a substrate 518. An active area 520 where the lasing action takes place is sandwiched between top and bottom Dielectric Bragg Reflectors (DBR) 522, 524 that act as front and rear mirrors to define an optical cavity. In a top emitting VCSEL, the bottom DBR is nearly 100% reflective while the top DBR has lower reflectivity so that a lasing beam 525 can emit from the top. Ideally, it is desirable to use a thin film material with high electrical conductivity and optical transmission at the wavelengths of interest, typically 1.3 and 1.5 μm for optical communication as an electrode. However, because of the lack of such a material, the traditional approach is to use a gold (Au) ring 526 as the top electrode, as shown in FIG. 17a. Electrical current 527 is injected from the ring around the peripheral area of the device and diffuses toward the center to the active region 520 to cause lasing. This approach tends to limit device size, since the large device size may cause nonuniform current density, which can cause poor output beam quality. This problem can be solved by locating a doped CdO thin film per the present invention directly onto the top of the optical beam exit area as the top electrode. The injected current 527 will be uniform to produce better optical beam quality. The power consumption will also be lower. Ferroelectric devices, including, for example, ferroelectric memory devices, electro-optical devices, and piezoelectric devices, represent another class of devices which may benefit from the use of a doped CdO film per the present invention; a prior art electro-optical ferroelectric device and an electro-optical ferroelectric device in accordance with the present invention are shown in FIGS. 18a and 18b, respectively. Ferroelectric devices are fabricated from slabs 540 of ceramic or single crystal materials, and require low resistivity electrodes on opposite faces for “poling” the material and modulating its properties. Traditional electrodes 542, 544 are made from platinum or other metal films. Because of the chemical and structural incompatibility between the metal and the ferroelectric materials—which are mostly oxides with a peroveskite lattice structure—repeated switching can cause ferroelectric material fatigue as the polarization decreases with increasing operating cycles. Structurally, the interface can degrade to cause eventual delamination and detachment. The use of the present doped CdO thin film 546, 548 can reduce this problem because the matched chemical properties of oxides and the similarity of its lattice structure (cubic structure) to the peroveskite lattice of the ferroelectric materials. Another advantage offered by using the doped C dO electrode in an electro-optical device fabricated from a single crystal ferroelectric material is that light can now transmit through the electrodes 546, 548 in the direction along the polarization of the crystal, as well as in the direction perpendicular to the direction of polarization inside the crystal. In the case of using metal electrodes 542, 544 (FIG. 18a), the light propagation must be in the direction from the side of the crystal and perpendicular to the direction of polarization inside the crystal. Electro-optical devices using the doped CdO electrode can operate in the 1.3 and 1.5 micron wavelength ranges with little absorption loss. Another type of device which may benefit from the use of a doped CdO film per the present invention is a Pockels' cell, which is an electro-optic device in which birefringence is modified under the influence of an applied voltage. If the birefringent medium is a solid, then the applied voltage is normally applied using transparent, electrically-conductive films applied on both sides of the solid. If the birefringent medium is a liquid, then transparent, electrically-conductive films are applied on the inside of the window used to confine the liquid. FIG. 19a illustrates an arrangement for a Pockels' cell in which the birefringent medium 550 is a solid. The light must pass through the two doped CdO film electrodes 552, 554 that modify the birefringence. FIG. 19b shows an arrangement for a Pockels' cell in which the birefringent medium 556 is a liquid. Here, the two doped CdO film electrodes 558, 560 that apply the voltage to the liquid are applied on the inside of window layers 562, 564. Yet another possible application of a doped CdO film per the present invention is with optical micro-electromechanical devices (MEM devices), in which a transparent electrode is used as part of the activation mechanism for the device's electrostatic actuator. There could be many different MEM device embodiments, including, for example, a multi-faceted focusing mirror, or a variable-wavelength filter or reflector. While several illustrative embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Such variations and alternate embodiments are contemplated, and can be made without departing from the spirit and scope of the invention as defined in the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates to transparent conductive thin films for use in electro-optical devices. 2. Description of the Related Art Many electro-optical devices operating in the infrared (generally, wavelengths of ˜0.7 μm to ˜14 μm) require conductive thin films that are extremely transparent. Such devices include liquid crystal cells for beam steering, spatial light modulators, and optical switches for fiber optic communications, switchable and/or tunable polarization modification components, and long wavelength vertical cavity surface emitting lasers (VCSELs). Conventional transparent conductive oxides such as indium tin oxide (ITO), zinc oxide (ZnO), and tin oxide (SnO 2 ) cannot fulfill the requirements of these applications. These materials are mostly transmissive in the visible; however, transmission in the infrared drops due to free carrier absorption. The transmission values versus wavelength for an ITO film on a glass substrate are shown in FIG. 4 . For ITO films with a sheet resistance of about 140 Ω/□ the transmission is about 98% at 1.3 μm and about 97% at 1.5 μm; 1.3 μm and 1.5 μm are critical values for fiber-optic communication and long wavelength VCSEL applications. Other possible optically transparent conductive materials such as doped semiconductor wafers or epitaxial layers (Si, Ge, GaAs, InP doped) have limited utility because they do not cover the entire spectral range, have a limited size, and are expensive. U.S. Pat. No. 6,458,637, issued Oct. 1, 2002 to Jeffrey T. Cheung, directed to transparent and conductive zinc oxide films, describes the introduction of hydrogen or a hydrocarbon gas (in addition to oxygen) into the vacuum chamber during growth of the film using pulsed laser deposition from a 2.0 atomic wt. % gallium-doped ZnO target. This approach incorporated hydrogen atoms into the ZnO lattice during growth and activates them to behave as electron donors so that a low electrical resistivity film (0.9-3×10 −4 Ω-cm) could be grown at low temperature. The process was found to work only when gallium was also present in the lattice. The resultant films, with or without doping, had a transmissivity of no more then about 90% at wavelengths of 0.35 to 2.0 μm. Cadmium oxide (CdO) films doped with indium (CdO:In) have been prepared in the past for flat-panel displays and solar cells which require high transparency to visible light. However, these films are well known for their toxicity, and therefore the prior art has steered away from developing such films. Minami et al. reports that CdO:In films have been prepared with a resistivity of the order of 10−5 Ω-cm for flat-panel displays and solar cells, but he states that they are of no practical use because of Cd toxicity. (Minami, Tadatsugu, “New n-Type Transparent Conducting Oxides”, Transparent Conducting Oxides , Volume 25, No. 8 , August 2000, p.38). Further, because these films have a yellow color, which differentiates them from prior art transparent films that are clear in appearance, one skilled in the art would be steered away from using these films for any applications requiring transparent films. Undoped CdO has been prepared by sputtering, MOCVD, and spray pyrolysis (Murthy, L. C. S. & Rao, K. S. R. K., “Thickness Dependent Electric Properties of CdO Thin Films Prepared by Spray Pyrolysis Method,” Bulletin of Material Science , Vol. 22, No. 6, pp.953-957 (October 1999); Subramarnyam, T. K et al., “Preparation and Characterization of CdO Films Deposited by DC Magnetron Reactive Sputtering”, Materials Letter, Vol. 35, pp.214-220, (May 1998); Baranov, A M et al., “Investigation of the Properties of CdO Films”, Tech. Phys. Ltr, 23, (10) pp.805-806 (October 1997)). Transmission no greater then about 85% has been reported in the wavelength range of 0.6-1.6 μm. Representative data, doping and method of fabrication for these references, along with additional references reporting on CdO films, are listed in Table 1 below. TABLE 1 LITERATURE REPORTING ON CDO FILMS Thick. Growth Resistivity T % & Approach Dopant Substrate Å Temp Ohm-cm range Pulsed Laser Intrinsic* Glass R. T. + post >10 −3 60-90% @ Sputtering 1 annealing 0.5-2.0 μm Activated Reactive Intrinsic* Glass 350 4 × 10 −4 70-80% @ Evaporation 2 0.5-.85 μm Solution Growth 3 Intrinsic* Glass 2000 R. T. + post 2-5 × 10 −4 75-85% @ annealing 0.5-0.9 μm Ion beam Intrinsic* Glass 5000 50-70 C. 5 × 10 −3 70-80% @ sputtering 4 0.5-.85 μm** Spray pyrolysis 4 Intrinsic* Glass 5000 180-225 2-5 × 10 −3 70-80% @ 0.5-.85 μm** DC reactive Undoped Glass R. T. + post 10 2 -10 −3 40-85%@ sputtering 5 annealing 0.5-.90 μm 6 sputtering Indium 10 −5 Spray Pyrolysis 7 Undoped DC Magnetron Undoped Glass 5-49 85% @ Reactive 0.6-1.6 μm Sputtering 8,9 Magnetron Undoped >7 × 10 −4 60-70% @ Sputtering 10 0.5-0.9 μm Spray Pyrolysis 11 Fluorine 80-90%@ 0.4-0.7 μm; <80% @ >0.7-1.2 μm Low Press. CVD 12 Undoped Glass 500-800 2 × 10 −3 *Intrinsic dopant means that donors in the materials are due to defects not impurities **Measured against glass slide as reference 1 Shaganov, II, et al., “Obtaining transparent oxide conducting coatings by pulsed laser sputtering” Sov. J. Opt. Technol. 48(5), p 280-282 (May, 1981) 2 Pahtak, Girish et al, “Deposition and properties of cadmium oxide films by activated reactive evaporation”, Thin Solid Films, 245, p17-26 (1994) 3 Varkey, AJ et al, “Transparent conducting cadmium oxide thin films prepared by a solution growth technique”, Thin Solid Films, 239, p211-213 (1994) 4 Chu, TL et al, “Degenerate Cadmium Oxide films for electronic devices”, J. Electronic Materials , 19, p1003- (1990) 5 Tanaka, K et al “Electrical and optical properties of sputtered CdO films”, Japanese J. of Appl. Phys., 8(6), p681-691 (June 1969) 6 Minami, Tadatsugu, “New n-Type Transparent Conducting Oxides”, Transparent Conducting Oxides, 25, (8), p38-44 (August 2000) 7 Murthy, L. C. S. et al., “Thickness Dependent Electric Properties of CdO Thin Films Prepared by Spray Pyrolysis Method”, Bulletin of Material Science, 22, (6), pp953-7 (Oct. 1999) 8 Subramarnyam, T. K et al, “Preparation and Characterization of CdO Films Deposited by DC Magnetron Reactive Sputtering”, Materials Letter, 35, pp 214-220, (May 1998) 9 Subramarnyam, T. K et al, “Influence of Oxygen Pressure on the Structural and Optical Properties of DC Magnetron Reactive Sputtered Cadmium Oxide”, Physica Scripta, 57, p317 - (1998) 10 Baranov, AM. et al, “Investigation of the Properties of CdO Films”, Tech. Phys. Ltr, 23, (10) pp 805-806 (October 1997) 11 Ferro, R et al “F-Doped CdO Thin Films Deposited by Spray Pyrolysis”, PMS. State. Sol. (a) 177, P477-483 (2000) 12 Coutts, TJ et al, “Search for improved transparent and conducting oxides: A fundamental investigation of CdO, Cd 2 SnO 4 , and Zn 2 SnO 4 ”, J Vac. Sci. Tech., A18, (6), p2646-2660, (Nov/Dec 2000) There is a need for films with lower resistivity and low optical absorption at wavelengths that extend from the short-wavelength infrared (SWIR) (1-2 μm) through the mid-wavelength infrared (MWIR) (3-5 μm) and possibly into the long wavelength infrared (LWIR) (8-12 μm). As an example, devices operating in the fiber telecommunication bands at 1.3 or 1.5 μm require an optical transmission of at least 99%. | <SOH> SUMMARY OF THE INVENTION <EOH>A doped cadmium oxide (CdO) film with high optical transmission and suitable electrical conductivity has been developed for use in applications requiring conductive, infrared transparent films. Suitable dopants for the film include any of the Group III elements (i.e. boron, aluminum, gallium, indium or thallium), bismuth, fluorine, and hydrogen (as a co-dopant) if properly processed. The new doped film is substantially transparent to infrared radiation in the range of between about 0.7 μm and 14 μm. Films made according to the invention have a sheet resistance of <600 Ω/□ (typically ≦200 Ω/□), and have exceptionally low optical absorption throughout the IR range: less than 4% (typically <1%) in the SWIR, less than 10% (typically <3%) in the MWIR, and less than 20% (typically <4%) in the LWIR. In addition, a film per the present invention having a sheet resistance of <600 Ω/□ (typically ≦200 Ω/□) has an absorption loss of about ≦0.2% at 1.3 μm and ≦0.5% at 1.5 μm. Films made according to the invention have a resistivity of less than 5× 10 −4 Ω-cm. Low resistivity films per the present invention can be prepared at much lower temperatures (20° C.) by co-doping with hydrogen. There are numerous applications for such films functioning as transparent, electrically conductive electrodes, including (but not limited to) liquid crystal cells for beam steering, spatial light modulators, optical switches for fiber optical communications, switchable and/or tunable polarization modification components, top transparent electrodes for SWIR (1.3 and 1.51 μm) VCSELs, Pockels' cells, MEMs devices, and ferroelectric cells. Other applications include radio frequency shielding of windows that can transmit infrared radiation. | 20040712 | 20080101 | 20050120 | 61742.0 | 0 | BLACKWELL, GWENDOLYN | THIN FILM INFRARED TRANSPARENT CONDUCTOR | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,889,768 | ACCEPTED | Accessory mount for a firearm | An accessory mount having a rail for removably mounting an accessory (such as a light beam generator) to a firearm, the accessory mount being removably secured to the firearm through utilization of an improved slide stop and pin combination, and positionally stabilized by utilization of a shock absorbing trigger guard bumper. | 1. An accessory mount for mounting an accessory device to a firearm, the firearm including a longitudinal barrel, a frame having a transverse bore and a trigger guard, the accessory mount comprising the combination of: a longitudinal rail adapted for removably securing the accessory device thereto; structural members upwardly projecting from the respective sides of said rail and adapted to straddle the frame with said rail beneath the barrel and forwardly of the trigger guard, said structural members including respective bores situated for being transversely aligned with the bore in the frame when the accessory mount is applied to the firearm; a pin configured for being received by said bores in said structural members and the bore in the frame when the accessory mount, is applied to the firearm; an appendage downwardly projecting from said rail in the vicinity of the rear end of said rail; and a rearwardly biased bumper carried by said appendage for being rearwardly urged against the trigger guard when the accessory mount is applied to the firearm with said pin received by said bores in said structural members and the bore in the frame. 2. The accessory mount according to claim 1, wherein: said appendage includes a front wall depending from said rail; and said rearwardly biased bumper includes a bumper and a spring secured between said bumper and said front wall. 3. The accessory mount according to claim 2, wherein: said bumper comprises a resilient bumper. 4. The accessory mount according to claim 2, wherein: said appendage includes lateral walls rearwardly extending from said front wall, said lateral walls adapted for straddling a front portion of the trigger guard when the accessory mount is applied to the firearm. 5. The accessory mount according to claim 1, including: a spacer on said rail for engaging a lower surface of the frame of the firearm. 6. The accessory mount according to claim 5, wherein: said spacer comprises a resilient pad. 7. The accessory mount according to claim 1, the firearm including a slide and a slide stop, wherein: said pin is secured to the slide stop for pivotally securing the slide stop to the frame of the firearm. 8. The accessory mount according to claim 1, the firearm including a slide and a slide stop, wherein: said pin is secured to the slide stop with the slide stop pivotable about said pin. 9. The accessory mount according to claim 1, the firearm including a slide and a slide stop, wherein: the slide stop is rotatably secured to said pin. 10. An accessory mount for mounting an accessory device to a firearm, the firearm including a longitudinal barrel, a frame having a transverse bore, a slide movable along the frame, and a trigger guard, the accessory mount comprising the combination of: a longitudinal rail adapted for removably securing the accessory device thereto; structural members upwardly projecting from the respective sides of said rail and adapted to straddle the frame with said rail beneath the barrel and forwardly of the trigger guard, said structural members including respective bores situated for being transversely aligned with the bore in the frame when the accessory mount is applied to the firearm; a pin configured for being received by said bores in said structural members and the bore in the frame when the accessory mount is applied to the firearm; a slide stop secured to said pin; an appendage downwardly projecting from said rail in the vicinity of the rear end of said rail; and a rearwardly biased bumper carried by said appendage for being rearwardly urged against the trigger guard when the accessory mount is applied to the firearm with said pin received by said bores in said structural members and the bore in the frame. 11. The accessory mount according to claim 10, wherein: said slide stop is pivotally secured about said pin. 12. The accessory mount according to claim 10, wherein: said appendage includes a front wall depending from said rail; and said rearwardly biased bumper includes a bumper and a spring secured between said bumper and said front wall. 13. The accessory mount according to claim 12, wherein: said bumper comprises a resilient bumper. 14. The accessory mount according to claim 12, wherein: said appendage includes lateral walls rearwardly extending from said front wall and straddling a front portion of the trigger guard when the accessory mount is applied to the firearm. 15. The accessory mount according to claim 10, including: a spacer on said rail engaging a lower surface of said frame when the accessory mount is applied to the firearm. 16. The accessory mount according to claim 15, wherein: said spacer comprises a resilient pad. 17. Firearm and accessory mount apparatus, comprising in combination: a firearm including a longitudinal barrel, a frame having a transverse bore, a slide movable along said frame, and a trigger guard; a longitudinal rail adapted for removably securing an accessory device thereto; structural members upwardly projecting from the respective sides of said rail and straddling said frame with said rail beneath the barrel and forwardly of the trigger guard, said structural members including respective bores transversely aligned with said bore in said frame; a pin received by said bores in said structural members and said bore in the frame; a slide stop secured to said pin; an appendage downwardly projecting from said rail in the vicinity of the rear end of said rail; and a rearwardly biased bumper carried by said appendage and rearwardly urged against the trigger guard. 18. The apparatus according to claim 17, wherein: said slide stop is pivotally secured about said pin. 19. The apparatus according to claim 17, wherein: said appendage includes a front wall depending from said rail; and said rearwardly biased bumper includes a bumper and a spring secured between said bumper and said front wall. 20. The apparatus mount according to claim 19, wherein: said bumper comprises a resilient bumper. 21. The apparatus mount according to claim 19, wherein: said appendage includes lateral walls rearwardly extending from said front wall and straddling a front portion of said trigger guard. 22. The apparatus mount according to claim 17, including: a spacer on said rail engaging a lower surface of said frame. 23. The apparatus mount according to claim 22, wherein: said spacer comprises a resilient pad. 24. For a firearm including a longitudinal barrel, a frame having a transverse bore, and a slide longitudinally movable along the frame, apparatus comprising: a pin configured for being received by the transverse bore; and a slide stop pivotally secured to said pin. 25. The apparatus according to claim 24, wherein: said slide stop is rotatable about said pin. 26. Firearm apparatus comprising in combination: a firearm including a longitudinal barrel, a frame having a transverse bore, and a slide movable along said frame; a pin received by said bore in said frame; and a slide stop pivotally secured to said pin. 27. The apparatus according to claim 26, wherein: said slide stop is rotatable about said pin. | CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Application No. 60/520,106, filed Nov. 13, 2003, which application is incorporated herein by reference. BACKGROUND OF THE INVENTION This invention relates to accessory mounts for mounting an accessory to a firearm, and more particularly to a mount or interface adapter for securing a light beam generator apparatus to a firearm including a handgun. Light beam generator apparatus, such as flashlights and laser aiming devices, have long been adapted for being secured to firearms as target illuminators and laser sights. For example, U.S. Pat. No. 4,777,754, issued to Edward C. Reynolds, Jr. and assigned to the assignee of the present invention, teaches a light beam generator assembly mounted to a firearm below the firearm's barrel and forwardly of the firearm's trigger guard. As applied to a handgun having a longitudinally moveable slide and a slide stop which causes the slide to lock open automatically after the last round has been fired and ejected, or which may be manually actuated at other times, the Reynolds light beam generating apparatus is pivotably secured to the handgun's slide stop pin transversely secured to the handgun frame. Positional stabilization of the secured light beam generator device on the handgun is facilitated by an adjustable set screw extending from the rear of the light beam generator housing and abutting the front surface of the handgun's trigger guard. Reynolds U.S. Pat. No. 4,777,754 is incorporated herein by reference. U.S. Pat. No. 6,378,237, issued to John W. Matthews and Paul Y. Kim and assigned to the assignee of the present invention, discloses an accessory mount or interface adapter clamped to the front of the handgun's trigger guard and longitudinally extending beneath the handgun's barrel. The accessory mount includes a rail having a pair of longitudinal grooves, one along each side of the rail, and the light beam generator apparatus includes a pair of longitudinal tongues for slidably mating with the mount's longitudinal grooves for being slidably held along the rail. A latch on the light beam generator housing co-acts with a transverse slot in the rail to releasably prevent further longitudinal movement of the light beam generator apparatus when such apparatus is at a predetermined position along the rail. Matthews et al. U.S. Pat. No. 6,378,237 is incorporated herein by reference. SUMMARY OF THE INVENTION By the present invention, there is provided an accessory mount or interface adapter having a rail for mounting a rail mountable accessory (in particular a light beam generator apparatus) to a firearm, which rail mount is removably secured to the firearm through utilization of an improved slide stop and pin combination, and which rail mount is positionally stabilized by utilization of a shock absorbing trigger guard bumper. According to a preferred embodiment of the present invention, there is provided an accessory mount for mounting an accessory device to a firearm, the firearm including a longitudinal barrel, a frame having a transverse bore and a trigger guard, the accessory device comprising the combination of: a longitudinal rail adapted for removably securing the accessory device thereto; structural members upwardly projecting from the respective sides of the rail and adapted to straddle the frame with the rail beneath the barrel and forwardly of the trigger guard, the structural members including respective bores situated for being transversely aligned with the bore in the frame when the accessory mount is applied to the frame; a pin configured for being received by the bores in the longitudinal members and the bore in the frame when the accessory mount is applied to the firearm; an appendage downwardly projecting from the rail in the vicinity of the rear end of the rail; and a rearwardly biased bumper carried by the appendage for being rearwardly urged against the trigger guard when the accessory mount is applied to the firearm with the pin received by the bores in the structural members and the bore in the frame. The preferred embodiment of the present invention is of particular application with a handgun including a slide and a slide stop, wherein the pin is secured to the slide stop for pivotally securing the slide stop to the frame of the firearm. The slide stop is preferably pivotable about the pin, such as by being rotatably secured to the pin. In the accessory mount of the preferred embodiment, the appendage includes a front wall depending from the rail, and the rearwardly biased bumper includes a bumper (preferably resilient) and a spring secured between the bumper and the front wall. Lateral walls may rearwardly extend from the front wall, for straddling a front portion of the trigger guard when the accessory mount is applied to the firearm. A spacer (such as a resilient pad) may be carried by the rail for engaging a lower surface of the frame of the firearm. According to an aspect of the present invention, firearm and accessory mount apparatus comprises in combination: a firearm including a longitudinal barrel, a frame having a transverse bore, a slide movable along the frame, and a trigger guard; a longitudinal rail adapted for removably securing an accessory device thereto; structural members upwardly projecting from the respective sides of the rail and straddling the frame with the rail beneath the barrel and forwardly of the trigger guard, the structural members including respective bores transversely aligned with the bore in the frame; a pin received by the bores in the structural members and the bore in the frame; a slide stop secured to the pin; an appendage downwardly projecting from the rail in the vicinity of the rear end of the rail; and a rearwardly biased bumper carried by the appendage and rearwardly urged against the trigger guard. The slide stop is preferably pivotally secured about the pin, and the appendage preferably includes a front wall depending from the rail, with a spring securing the preferably resilient bumper to the front wall. The appendage may include lateral walls rearwardly extending from the front wall and straddling a front portion of the trigger guard, as well as a spacer on the rail engaging a lower surface of the frame. According to another aspect of the present invention, there is provided firearm apparatus comprising in combination: a firearm including a longitudinal barrel, a frame having a transverse bore, and a slide movable along the frame; a pin received by the bore in the frame; and a slide stop pivotally secured to (preferably rotatable about) the pin. In accordance with a further aspect of the present invention, there is provided apparatus for a firearm including a longitudinal barrel, a frame having a transverse bore, and a slide longitudinally movable along the frame, such apparatus comprising: a pin adapted to be received by the transverse bore; and a slide stop pivotally secured to the pin, such as the slide stop being rotatable about the pin. BRIEF DESCRIPTION OF THE DRAWINGS The novel features believed to be characteristic of the invention, together with further advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the present invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. FIG. 1 is a side elevation view of a firearm with a light beam generator apparatus mounted to a preferred embodiment of an accessory mount or interface adapter according to the present invention, the accessory mount being secured to the firearm; FIG. 2 is similar to FIG. 1, except that the light beam generator apparatus has been removed therefrom; FIG. 3 is a top plan view of the accessory mount shown in FIGS. 1 and 2, in increased scale, but with the rear spring and trigger guard bumper removed for clarity of description; FIG. 4 is a cross-sectional view of the accessory mount shown in FIG. 3, taken along the line 4-4 of FIG. 3 and viewed in the direction of the appended arrows, FIG. 4 further including a front view representation of a light beam generator apparatus supportedly engaged by to the rail structure of the accessory mount; FIG. 5 is rear elevation view of the accessory mount shown in FIG. 3; FIG. 6 is a cross-sectional view of the accessory mount of FIG. 3 but including the rear spring and trigger guard bumper, taken along the line 6-6 of FIG. 3 and viewed in the direction of the appended arrows; FIG. 7 is a cross-sectional view of a fragment of the accessory mount of FIG. 3, taken along the line 7-7 of FIG. 5 and viewed in the direction of the appended arrows; FIG. 8 is a front elevation view of the trigger guard bumper included in the accessory mount shown in FIG. 6; FIG. 9 is a cross-sectional view of the trigger guard bumper of FIG. 8, taken along the line 9-9 of FIG. 8 and viewed in the direction of the appended arrows; FIG. 10 is a fragmentary cross-sectional view of the accessory mount as in FIG. 6, shown installed on the frame of the handgun; FIG. 11 is a plan view of a prior art slide stop and pin combination for securing the accessory mount of the present invention to the handgun; FIG. 12 is a plan view of a preferred embodiment of a modified slide stop and pin combination according to the present invention, for securing the accessory mount to the handgun; and FIG. 13 is a plan view of the pin shown in FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning to the drawings, there is illustrated in FIGS. 1 and 2 an example of a firearm 12, specifically a .45 caliber Model 1911 handgun, to which a preferred embodiment of an accessory mount or interface adapter 14 according to the present invention has been secured, FIG. 1 also showing a light beam generator apparatus or light module 16 mounted to the accessory mount 14. The firearm 12 includes a barrel 18 extending along a longitudinal axis a from the handgun's frame 20, and includes a slide 22 which houses the handgun's firing pin, firing pin block and extractor, and which cocks the hammer during recoil. The handgun 12 includes a trigger guard 24 in front of the handgun's trigger 26. As used herein, the word “longitudinal” describes a direction parallel to the axis a; “transverse” describes a horizontal direction perpendicular to the axis a when the barrel 18 is horizontally positioned; “above” means vertically above when the handgun 12 is held with its barrel 18 horizontal; “below” or “beneath” means vertically below when the handgun 12 is held with the barrel 18 horizontal; “front” or “forward” describes the direction toward the muzzle of the barrel 18 (i.e., to the left as shown in FIGS. 1-3, 6, 7 and 10); and “rear” or “rearward” describes the direction opposite the front or forward direction (i.e., to the right as shown in the drawing of FIGS. 1-3, 6, 7, 9 and 10). As is well known in handguns of this type, upon firing of the handgun the slide moves rearwardly with respect to the frame, extracting the fired cartridge case for ejection by the ejector, cocks the hammer and compresses the recoil spring, after which the slide moves forwardly feeding the next cartridge into the chamber and locking the breech. After the last round has been fired and ejected, a slide stop 28 is rotatably urged by the magazine follower to pivot about the axis of a transverse pin 32 supported by the frame 20, such that a projection 32—slidably retained along a longitudinal edge of the slide 22—of the slide stop 28 (see also FIG. 12) is upwardly urged to engage a recess 34 along such edge of the slide 22, for releasably stopping and holding the slide 22 in its rearward or open position. The accessory mount 14 includes a longitudinal rail 36 (parallel to longitudinal axis a′ which is beneath and parallel to the axis a when the accessory mount 14 is installed on the handgun 12) having two longitudinal grooves 38, one along each side of the rail 36. Two structural members or uprights 40 upwardly project from the rail 36 and longitudinally extend along the respective sides of the rail 36. Two transversely aligned bores 42 extend through the uprights 40 in the vicinity of the rear ends 44 of the structural members 40. An appendage 46 projects downwardly from the rail 36, and is preferably positioned toward the rear of the rail 36 and forwardly of the transverse bores 42. The accessory mount 14 is dimensioned such that it may be placed to the handgun 12 with the structural members 40 straddling the handgun's frame 20 beneath the barrel 18, and with the appendage 46 just forward of the trigger guard 24 when the structural members' rear bores 42 are transversely aligned with a transverse bore 48 (FIG. 10) in the frame 20 through which the handgun's slide stop pin 30 extends. The accessory mount 14 is thereby pivotally secured to the handgun frame 20 about the transverse axis t of the installed slide stop pin 30. The appendage 46 houses a rearwardly biased bumper 50 that is rearwardly urged against the trigger guard 24 when the accessory mount 14 is installed on the handgun 12. In its preferred embodiment, the appendage 46 is generally U-shaped in cross-section, and includes a vertical front wall 52 depending from the rail 36 and having a rearwardly extending post 54 surrounded by an annular groove 56, to which is secured the forward end of a helical spring 58. The bumper 50 is secured to the rearward end of the spring 58, such as by fitting the rearward end of the spring 58 into a front-opening annular cavity in the bumper 50. The spring 58 urges the rearward surface 62 of the bumper 50 against the trigger guard 24 when the accessory mount 14 is installed on the handgun 12 as described herein, providing a shock absorbing function between the accessory mount 14 (and the mounted light module 16) and the trigger guard 24 when the handgun 12 is fired. The bumper 50 is preferably of a resilient material such as neoprene. The appendage 46 may include lateral walls 61 rearwardly extending from the front wall 52, for straddling a front portion of the trigger guard 24 as shown in FIGS. 2, 5 and 10. A spacer 64, for example a pad of preferably resilient material such as neoprene, may be secured to the upper surface of the rail 36 for engaging the lower surface of the handgun frame 20, for spacing such frame surface from the upper surface of the rail 36 and for providing a cushion therebetween. When securing the accessory mount 14 to the handgun 12, the slide stop pin originally supplied with the handgun 12 may be removed from the frame bore 48. The accessory mount 14 is then placed to the handgun 12 with the bores 42 of uprights 40 aligned with the frame transverse bore 48, with the rail 36 longitudinally extending beneath the barrel 18 and with the accessory mount 14 rearwardly manipulated for rearwardly urging the biased bumper 62 against the trigger guard 24, whereupon the slide stop pin is inserted through the transverse bores 42 and 48. The accessory mount 14 of the present invention is preferably utilized in combination with a slide stop and pin combination where the slide stop projection 32 is slidably retained along the edge of the slide 22. One prior art slide stop and pin combination is shown in FIG. 11, wherein the pin 130 is fixedly secured (such as by welding) to the slide stop 128. Although such welded slide stop and pin combinations may be utilized with the accessory mount 14 of the present invention, it is preferred that the slide stop and pin combination of FIGS. 12 and 13 be utilized in which the slide stop 28 is rotatably secured to the pin 30. For example, one end of the slide stop pin 30 may include a neck portion 66 inserted within a bore 68 through the slide stop 28 and held by a retaining ring 70 cooperating with a further neck portion 72 of the pin 30., It has been found that the resulting pivotal securement of the slide stop 28 about the pin 30 facilitates installation of the accessory mount 14 to the handgun 12, by permitting free rotation of the slide stop 28 and consequent ease of positioning of the projection 32 to the slide 22 notwithstanding that the pin 30 may be forced against and held immobile by the surfaces of the bores 42 and/or 48. The accessory mount body of the present invention may be made using fabrication methods well known in the art, of well-known materials typically used in the art of making firearm accessory mounts including rigid and durable materials such as polymeric materials as well as lightweight aluminum alloys. After the accessory mount 14 has been installed on the handgun 12, an accessory such as a light beam generator apparatus may be mounted to the accessory mount 14. For example, as shown in FIGS. 1 and 4, the light module 16 includes a pair of longitudinal tongues 74 for slidably mating with the longitudinal grooves 38 of the accessory mount's rail 36. A latch on the light beam generator housing may co-act with a transverse slot 76 in the rail 36 for releasably preventing further longitudinal movement of the light beam generator 16 along the rail 36 when the light beam generator 16 is at a predetermined position along the rail 36. Light beam generators of this type are shown in the aforementioned U.S. Pat. No. 6,378,237 incorporated herein by reference. Thus, there has been described a preferred embodiment of an accessory mount for removably mounting an accessory to a firearm. The accessory mount of the preferred embodiment is removably secured to the firearm through utilization of an improved slide stop and pin combination, in which the slide stop is pivotally secured to the pin. The accessory mount preferred embodiment is positionally stabilized with respect to the firearm by means of a shock-absorbing trigger guard bumper. Other embodiments of the present invention and of its various aspects, and variations of the embodiment and its aspects described herein, may be developed without departing from the essential characteristics thereof. Accordingly, the invention should be limited only by the scope of the claims listed below. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates to accessory mounts for mounting an accessory to a firearm, and more particularly to a mount or interface adapter for securing a light beam generator apparatus to a firearm including a handgun. Light beam generator apparatus, such as flashlights and laser aiming devices, have long been adapted for being secured to firearms as target illuminators and laser sights. For example, U.S. Pat. No. 4,777,754, issued to Edward C. Reynolds, Jr. and assigned to the assignee of the present invention, teaches a light beam generator assembly mounted to a firearm below the firearm's barrel and forwardly of the firearm's trigger guard. As applied to a handgun having a longitudinally moveable slide and a slide stop which causes the slide to lock open automatically after the last round has been fired and ejected, or which may be manually actuated at other times, the Reynolds light beam generating apparatus is pivotably secured to the handgun's slide stop pin transversely secured to the handgun frame. Positional stabilization of the secured light beam generator device on the handgun is facilitated by an adjustable set screw extending from the rear of the light beam generator housing and abutting the front surface of the handgun's trigger guard. Reynolds U.S. Pat. No. 4,777,754 is incorporated herein by reference. U.S. Pat. No. 6,378,237, issued to John W. Matthews and Paul Y. Kim and assigned to the assignee of the present invention, discloses an accessory mount or interface adapter clamped to the front of the handgun's trigger guard and longitudinally extending beneath the handgun's barrel. The accessory mount includes a rail having a pair of longitudinal grooves, one along each side of the rail, and the light beam generator apparatus includes a pair of longitudinal tongues for slidably mating with the mount's longitudinal grooves for being slidably held along the rail. A latch on the light beam generator housing co-acts with a transverse slot in the rail to releasably prevent further longitudinal movement of the light beam generator apparatus when such apparatus is at a predetermined position along the rail. Matthews et al. U.S. Pat. No. 6,378,237 is incorporated herein by reference. | <SOH> SUMMARY OF THE INVENTION <EOH>By the present invention, there is provided an accessory mount or interface adapter having a rail for mounting a rail mountable accessory (in particular a light beam generator apparatus) to a firearm, which rail mount is removably secured to the firearm through utilization of an improved slide stop and pin combination, and which rail mount is positionally stabilized by utilization of a shock absorbing trigger guard bumper. According to a preferred embodiment of the present invention, there is provided an accessory mount for mounting an accessory device to a firearm, the firearm including a longitudinal barrel, a frame having a transverse bore and a trigger guard, the accessory device comprising the combination of: a longitudinal rail adapted for removably securing the accessory device thereto; structural members upwardly projecting from the respective sides of the rail and adapted to straddle the frame with the rail beneath the barrel and forwardly of the trigger guard, the structural members including respective bores situated for being transversely aligned with the bore in the frame when the accessory mount is applied to the frame; a pin configured for being received by the bores in the longitudinal members and the bore in the frame when the accessory mount is applied to the firearm; an appendage downwardly projecting from the rail in the vicinity of the rear end of the rail; and a rearwardly biased bumper carried by the appendage for being rearwardly urged against the trigger guard when the accessory mount is applied to the firearm with the pin received by the bores in the structural members and the bore in the frame. The preferred embodiment of the present invention is of particular application with a handgun including a slide and a slide stop, wherein the pin is secured to the slide stop for pivotally securing the slide stop to the frame of the firearm. The slide stop is preferably pivotable about the pin, such as by being rotatably secured to the pin. In the accessory mount of the preferred embodiment, the appendage includes a front wall depending from the rail, and the rearwardly biased bumper includes a bumper (preferably resilient) and a spring secured between the bumper and the front wall. Lateral walls may rearwardly extend from the front wall, for straddling a front portion of the trigger guard when the accessory mount is applied to the firearm. A spacer (such as a resilient pad) may be carried by the rail for engaging a lower surface of the frame of the firearm. According to an aspect of the present invention, firearm and accessory mount apparatus comprises in combination: a firearm including a longitudinal barrel, a frame having a transverse bore, a slide movable along the frame, and a trigger guard; a longitudinal rail adapted for removably securing an accessory device thereto; structural members upwardly projecting from the respective sides of the rail and straddling the frame with the rail beneath the barrel and forwardly of the trigger guard, the structural members including respective bores transversely aligned with the bore in the frame; a pin received by the bores in the structural members and the bore in the frame; a slide stop secured to the pin; an appendage downwardly projecting from the rail in the vicinity of the rear end of the rail; and a rearwardly biased bumper carried by the appendage and rearwardly urged against the trigger guard. The slide stop is preferably pivotally secured about the pin, and the appendage preferably includes a front wall depending from the rail, with a spring securing the preferably resilient bumper to the front wall. The appendage may include lateral walls rearwardly extending from the front wall and straddling a front portion of the trigger guard, as well as a spacer on the rail engaging a lower surface of the frame. According to another aspect of the present invention, there is provided firearm apparatus comprising in combination: a firearm including a longitudinal barrel, a frame having a transverse bore, and a slide movable along the frame; a pin received by the bore in the frame; and a slide stop pivotally secured to (preferably rotatable about) the pin. In accordance with a further aspect of the present invention, there is provided apparatus for a firearm including a longitudinal barrel, a frame having a transverse bore, and a slide longitudinally movable along the frame, such apparatus comprising: a pin adapted to be received by the transverse bore; and a slide stop pivotally secured to the pin, such as the slide stop being rotatable about the pin. | 20040712 | 20060718 | 20050602 | 69768.0 | 0 | HAYES, BRET C | ACCESSORY MOUNT FOR A FIREARM | SMALL | 0 | ACCEPTED | 2,004 |
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10,889,966 | ACCEPTED | Pharmaceutically effective compounds | The subject invention relates to carboxamidine derivatives, to pharmaceutical compositions containing the carboxamidine derivatives of the invention, and the use thereof for the treatment of vascular diseases and in the preparation of pharmaceutical compositions for the treatment of vascular diseases. | 1. A compound selected from the group consisting of: i) a compound of formula I wherein R1 and R2 are independently hydrogen, a straight chained C1-6 alkyl group optionally substituted with a phenyl group, or a branched C1-6 alkyl group optionally substituted with a phenyl group, or R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, wherein the heterocyclic ring is optionally substituted with one or more hydroxy, oxo or benzyl groups; A is a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl, nitro group, or halogen, or is a 5-6 membered heteroaromatic ring containing at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur, wherein the nitrogen heteroatom is optionally an N-oxide structure; n is 0, 1, or 2; z is 0 or 1; X is halogen or —NR4R5, wherein R4 and R5 are independently hydrogen, a straight chained C1-6 alkyl group or a branched C1-6 alkyl group, Y is a hydrogen, hydroxy group, halogen, or C1-22 acyloxy group, wherein if R4 and R5 are both hydrogen, then Y is other than a hydroxy group, with the proviso that a) if Y is hydrogen and/or X is an —NR4R5 or if X is —NR4R5 group, R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, wherein the heterocyclic ring is substituted with one or more hydroxy, oxy, or benzyl groups, and/or A is a nitrogen containing heteroaromatic ring, wherein said ring has an N-oxide structure on the nitrogen heteroatom, or b) if X is halogen and Y is hydroxy or acyloxy, R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, wherein said heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups, or a stereoisomer or salt thereof; ii) a compound of formula II wherein R1 and R2 are independently hydrogen, a straight chained C1-6 alkyl group optionally substituted with a phenyl group, a branched C1-6 alkyl group optionally substituted with a phenyl group, or R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, wherein said heterocyclic ring is optionally substituted with one or more hydroxy, oxo or benzyl groups, A is a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl, nitro, or halogen, or is a 5-6 membered heteroaromatic ring containing at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur, wherein the nitrogen heteroatom is optionally an N-oxide structure; n is 0, 1, or 2; z is 0 or 1; X is oxygen; R3 is selected from the group consisting of hydrogen, straight chained C1-6 alkyl group, and branched chained C1-6 alkyl group; Y is selected from the group consisting of hydrogen, hydroxy, halogen, and C1-22 acyloxy group, with the proviso that if Y is other than halogen, R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, wherein said heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups and/or A is a nitrogen containing heteroaromatic ring, which has N-oxide structure on the nitrogen heteroatom; or a stereoisomer or salt thereof; and iii) a compound of formula III wherein R1 and R2 are independently hydrogen, straight chained C1-6 alkyl group optionally substituted with a phenyl group, branched C1-6 alkyl group optionally substituted with a phenyl group, or R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, wherein said heterocyclic ring is optionally substituted with one or more hydroxy, oxo or benzyl groups; A is a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl, nitro, or halogen, or is a 5-6 membered heteroaromatic ring containing at least one heteroatom is selected from the group consisting of nitrogen, oxygen and sulfur, wherein the nitrogen heteroatom is optionally an N-oxide structure; n is 0, 1, or 2; z is 0 or 1; with the proviso that if R1 and R2 independently represent a hydrogen atom, a straight chained C1-6 alkyl group optionally substituted with a phenyl group, a branched C1-6 alkyl group optionally substituted with a phenyl group, or together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, then A is a heteroaromatic ring containing oxygen or sulfur heteroatom or an N-containing heteroaromatic ring having an N-oxide structure on the nitrogen heteroatom and if A is a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl or nitro groups or halogen, or is a 5-6 membered N-containing heteroaromatic ring, then R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, wherein said heterocyclic ring is substituted with one or more hydroxy, oxo, or benzyl groups; or a stereoisomer or salt thereof. 2. The compound according to claim 1, wherein the compound is N-[3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamidine or a salt thereof. 3. The compound according to claim 1, wherein the compound is N-[3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamidine or salts. 4. The compound according to claim 1, wherein the compound is N-[2-hydroxy-3-(1-piperidinyl)propoxy]-N′-n-butyl-pyridin-1-oxide-4-carboxamidine, or a stereoisomer and/or salt thereof. 5. The compound according to claim 1, wherein the compound is N-[3-(1-oxido-1-piperidinyl)propoxy]-3-nitro-benzimidoyl-chloride, or a hydrate and/or salt thereof. 6. The compound according to claim 1, wherein the compound is 2-chloro-N-[3-(4-oxido-4-morpholinyl)propoxy]-benzimidoyl chloride or a salt thereof. 7. The compound according to claim 1, wherein the compound is 5,6-dihydro-5-[(1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine, or a stereoisomer and/or salt thereof. 8. The compound according to claim 1, wherein the compound is 5,6-dihydro-5-[(4-benzyl-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine, or a stereoisomer and/or salt thereof. 9. The compound according to claim 1, wherein the compound is 5,6-dihydro-5-[(4-benzyl-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine, or a stereoisomer and/or salt thereof. 10. The compound according to claim 1, wherein the compound is 5,6-dihydro-5-[(1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine, or a stereoisomer and/or salt thereof. 11. The compound according to claim 1, wherein the compound is 5,6-dihydro-5-[(1-oxido-1-piperidinyl)methyl]-3-(oxido-3-pyridyl)-4H-1,2,4-oxadiazine, or a stereoisomer and/or salt thereof. 12. The compound according to claim 1, wherein the compound is 5,6-dihydro-5-[(4-hydroxy-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine, or a stereoisomer and/or salt thereof. 13. The compound according to claim 1, wherein the compound is N-[2-chloro-3-(1-piperidinyl)propoxy]-3-benzimidoyl-chloride hydrochloride, or a stereoisomer and/or salt thereof. 14. The compound according to claim 1, wherein the compound is N-[2-hydroxy-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxaminde, or a stereoisomer and/or salt thereof. 15. A pharmaceutical comprising a compound of formulae I, sing a compound of formulae I, II, or III as defined in claim 1. 16. A method for the treatment or prevention of vascular disease or diseases related to vascular disorders comprising administering an effective amount of a compound to a patient, wherein the compound is a compound of formulae I, II, or III as defined in claim 1. | CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of International patent application No. PCT/HU03/00003, filed Jan. 10, 2003. DETAILED DESCRIPTION OF THE INVENTION The invention relates to pharmaceutically effective hydroxylamine derivatives, which are useful in the treatment of vascular diseases. The invention relates to the use of compounds of general formulae (I), (II) and (III)— R1 and R2 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group optionally substituted with a phenyl group, or R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, which heterocyclic ring is optionally substituted with one or more hydroxy, oxo or benzyl groups, A represents a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl or nitro groups or halogen atoms, or a 5-6 membered heteroaromatic ring containing one or more nitrogen, oxygen or sulfur heteroatoms, optionally having N-oxide structure on the nitrogen heteroatom, n is zero, 1 or 2, n is zero or 1, in compounds of general formulae (I), X represents a halogen atom or —NR4R5 group, where R4 and R5 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group, in compounds of general formulae (II), X refers to oxygen atom, R3 represents a hydrogen atom or a straight or branched C1-6 alkyl group, Y represents a hydrogen atom or hydroxy group, halogen atom or C1-22 acyloxy group, with the restriction that if R4 and R5 are simultaneously hydrogen atoms, Y is other than hydroxy group, with the proviso that in compounds of general formulae (I) and (II) where Y is other than halogen, a) R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, which heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups and/or b) A is an N-containing heteroaromatic ring, which has N-oxide structure on the nitrogen heteroatom, and/or c) z is 1, with the further proviso that if X is halo and Y is hydroxy or acyloxy in compounds of general formulae (I), R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, which heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups and with the proviso for compounds of general formulae (III) that if R1 and R2 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group optionally substituted with a phenyl group, or together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, then A is a heteroaromatic ring containing oxygen or sulfur heteroatom or an N-containing heteroaromatic ring having N-oxide structure on the nitrogen heteroatom and if A is a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl or nitro groups or halogen atoms, or a 5-6 membered N-containing heteroaromatic ring, then R1 and R together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, which heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups, and of the salts and optically active forms of the above compounds for the production of pharmaceutical products used in the treatment and/or prevention of vascular diseases or diseases related to vascular disorders. Compounds of similar structure are known from WO 97/16439. These compounds increase molecular chaperon expression, or molecular chaperon activity in cell exposed to a physiological stress. Due to this characteristic, they are useful for the treatment of diseases connected with the functioning of the chaperon system. The protective and regenerating effect that compounds of similar structures have for vascular endothelial cells is known from WO 98/06400. These compounds are primarily useful for the prevention of damage caused by ischemia and for the treatment of cardiovascular and cerebrovascular diseases. We have found that when the hydroxylamine derivatives described in the cited literature are chemically modified, preferably in such a way that, according to general formulae (I), (II) and (III) above, 1) a halogen atom is introduced into the propylene group of the aminopropyl group connected to the hydroxylamine part as substituent and/or 2) N-oxide is formed on the nitrogen atoms in the terminal groups of the molecule, namely on the nitrogen atom connected to the propylene group of the above mentioned aminopropyl group and/or on the nitrogen atom located in the heteroaromatic ring of the molecule, then the resulting products are hydroxylamine derivatives which possess much more favorable pharmacological properties against vascular illnesses than known compounds which have been found to be useful for this purpose. Namely, the effect of these compounds is more intensive than that of the known prior art compounds used for similar purposes. Therefore they are especially useful as active ingredients in the treatment or prevention of vascular diseases or diseases associated with vascular disorders. Based on this observation, this invention relates to the use of compounds of general formulae (I), (II) and (III)—where R1, R2, R3, A, X, Y, n and z are as above—, and to the use of the salts and optically active forms of the above compounds for the production of pharmaceutical products for the treatment and/or prevention of vascular diseases or diseases associated with vascular disorders. A considerable part of compounds of general formulae (I), (II) and (III) are novel compounds. Novel compounds are compounds of general formulae (I) wherein R1 and R2 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group optionally substituted with a phenyl group, or R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, which heterocyclic ring is optionally substituted with one or more hydroxy, oxo or benzyl groups, A represents a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl or nitro groups or halogen atoms, or a 5-6 membered heteroaromatic ring containing one or more nitrogen, oxygen or sulfur heteroatoms, optionally having N-oxide structure on the nitrogen heteroatom, n is zero, 1 or 2, z is zero or 1, X represents a halogen atom or —NR4R5 group, where R4 and R5 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group, Y represents a hydrogen atom or hydroxy group, halogen atom or C1-22 acyloxy group, with the restriction that if R4 and R5 are simultaneously hydrogen atoms, then Y is other than hydroxy group, with the proviso that a) if Y is hydrogen and/or X is a —NR4R5 group, where R4 and R5 have the above meanings, R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, which heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups and/or A is an N-containing heteroaromatic ring, which has N-oxide structure on the nitrogen heteroatom, or b) if X is halo and Y is hydroxy or acyloxy, R1 and R2 together with the nitrogen atom attached thereto form a 5-7 5 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, which heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups, and the stereoisomers of the above compounds and their salts. Novel compounds are compounds of general formulae (II) wherein R1 and R2 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group optionally substituted with a phenyl group, or R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, which heterocyclic ring is optionally substituted with one or more hydroxy, oxo or benzyl groups, A represents a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl or nitro groups or halogen atoms, or a 5-6 membered heteroaromatic ring containing one or more nitrogen, oxygen or sulfur heteroatoms, optionally having N-oxide structure on the nitrogen heteroatom, n is zero, 1 or 2, z is zero or 1, X represents an oxygen atom, R3 represents a hydrogen atom or a straight or branched C1-6 alkyl group, Y represents a hydrogen atom or hydroxy group, halogen atom or C1-22 acyloxy group, with the proviso that if Y is other than halo, R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, which heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups and/or A is an N-containing heteroaromatic ring, which has N-oxide structure on the nitrogen heteroatom, and the stereoisomers of the above compounds and their salts. Novel compounds are compounds of general formulae (III) wherein R1 and R2 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group optionally substituted with a phenyl group, or R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, which heterocyclic ring is optionally substituted with one or more hydroxy, oxo or benzyl groups, A represents a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl or nitro groups or halogen atoms, or a 5-6 membered heteroaromatic ring containing one or more nitrogen, oxygen or sulfur heteroatoms, optionally having N-oxide structure on the nitrogen heteroatom, n is zero, 1 or 2, z is zero or 1, with the proviso that if R1 and R2 independently represent a hydrogen atom or a straight or branched C1-6 alkyl group optionally substituted with a phenyl group, or together with the nitrogen atom attached thereto form a 5-7 membered saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatoms, then A is a heteroaromatic ring containing oxygen or sulfur heteroatom or an N-containing heteroaromatic ring having N-oxide structure on the nitrogen heteroatom and if A is a phenyl group optionally substituted with one or more C1-4 alkyl, C1-4 haloalkyl or nitro groups or halogen atoms, or a 5-6 membered N-containing heteroaromatic ring, then R1 and R2 together with the nitrogen atom attached thereto form a 5-7 membered, saturated heterocyclic ring optionally containing further nitrogen and/or oxygen heteroatom, which heterocyclic ring is substituted with one or more hydroxy, oxo or benzyl groups, and the stereoisomers of the above compounds and their salts. The invention relates to the above compounds. The invention further relates to pharmaceutical products that contain as active ingredient compounds of general formulae (I), (II) and (III), or their stereoisomers, or their salts, where R1, R2, R3, A, X, Y, n and z are as defined above. The following compounds of the invention are especially preferable: 1. N-[3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamidine 2. N-[3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboximidoyl chloride 3. N-[2-hydroxy-3-(1-piperidinyl)propoxy]-N′-n-butyl-pyridin-1-oxide-4-carboxamidine 4. N-[3-(1-oxido-1-piperidinyl)propoxy]-3-nitro-benzimidoyl-chloride dihydrate 5. 2-chloro-N-[3-(4-oxido-4-morpholinyl)propoxy]-benzimidoyl chloride 6. (R,S)-5,6-dihydro-5-[(1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine 7. 5,6-dihydro-5-[(4-benzyl-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine 8. (R) or (S)-5,6-dihydro-5-[(2-oxo-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine 9. (+)-5,6-dihydro-5-[(1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine 10. (R) or (S)-5,6-dihydro-5-[(1-oxido-1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine 11. 5,6-dihydro-5-[(4-hydroxy-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine 12. N-[2-chloro-3-(1-piperidinyl)propoxy]-3-benzimidoyl-chloride hydrochloride 13. N-[2-hydroxy-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamide The biological effects of the compounds of the invention were tested by the following experiments: Wounding Migration Assay in Endothelial Cell Culture The effect of the compounds of the invention on the wounded monolayers of human umbilical vein endothelial cells (HUVEC) were studied in a cell culture system (in vitro). After reaching confluence, the HUVEC cells were wounded according to the method of Yamamura et al. (J. Surgical Res. 63, 349-354, 1996). The number of migrated cells were registered using computerized image analysis 24 hours after wounding in the absence and presence of the active agents under testing in a concentration of 10−6 M. The active ingredient described in publication no. WO 98/06400, namely 5,6-dihydro-5-(1-piperidinyl)-methyl-3-(3-pyridyl)-4H-1,2,4-oxadiazine was used as reference compound. The obtained results are given in Table 1. TABLE 1 No. of the compound cell/mm2 24 hours Reference 30 4 45 8 48 9 52 II 51 12 60 13 54 In the following, we give the results of the test of blood vessel relaxing effect, performed in vitro on rat vessels, and also the morphological results of the thoracic aorta. Three-month-old, genetically hypertonic (SH) Wistar Okamoto rats were treated for one month with various test compounds. Thereafter the functional and morphological tests were performed. The Vaso-Relaxing Effect of the Compounds of the Invention on the Thoracic Aorta of SH Rats (In Vitro Testing) The test was performed by the method known from the literature [Japan J. Pharmacol., 59, 339-347 (1992)]. The SH rats were anesthetized with Nembutal (40 mg/kg, i.p.), then the thoracic aorta was removed and placed in oxygenized (95% O2+5% CO2) Krebs-Henseleit solution. The composition of the solution (mM): NaCl 118, KCl 4.7, CaCl2 2.52, MgSO4 1.64, NaHCO3 24.88, KH2PO4 1.18, glucose 5.5. The 3-mm-long aorta rings were suspended in a 20 ml organ bath of 37° C. The resting tension was 1 g, which was maintained throughout the equilibration. During the 1 hour equilibration, the medium was changed in every 20 minutes. The vessels were contracted with 10−6 M methoxamine (approximately 80% of maximal contraction). After reaching the maximal contraction, we tested the vasodilation resulting as the effect of the acetylcholine (Ach) (10−6-10−4 M), which informed us about the condition of the 5 endothelium of the vessel wall. The contraction force was measured by an isometric strain gauge (SG-01D, Experimentia Ltd), and was registered on an OH-850 polygraph (Radelkis). At this time again, 5,6-dihydro-5-(1-piperidinyl)-methyl-3-(3-pyridyl)-4H-1,2,4-oxadiazine as described in WO 98/06400 was used as a reference compound. The results of these tests are summarized in Table 2. TABLE 2 The vessel relaxing effect of the compounds of the invention on the thoracic aorta of SH rats (in vitro testing). Materials Ach doses (M) Doses 10−6 10−5 10−4 SH control 55.1 57.2 72.0 N = 10 Reference 77.4 80.2 81.7 n = 12; 20 mg/kg Compound no. 4 82.5 84.9 88.1 n = 11; 5 mg/kg Compound no. 8 80.3 88.0 89.2 n = 11; 20 mg/kg Compound no. 9 87.0 87.9 93.2 n = 10; 5 mg/kg Compound no. 11 79.7 85.1 86.0 n = 12; 10 mg/kg Compound no. 12 82.3 83.5 80.4 n = 12; 20 mg/kg Compound no. 13 88.4 90.3 95.2 n = 10 As the table shows, we registered a 30% relaxation decrease in the case of untreated hypertonic animals, which is the result of hypertonia-induced endothelial damage. The test compounds improved the relaxation properties of the vessels significantly, which is the result of the improved functioning of the endothelium, due to the relative increase of the endothelium-related relaxation factors. Morphological Testing of the Thoracic Aortas with Electron Microscopy The test was performed according to the procedure known from the literature (Br. J. of Pharmacol., 1995; 115, 415-420). 1 mm pieces of the aorta wall was cut out of the thoracic aorta of the rats, and were then fixed with 2.5% glutaraldehyde at room temperature for 2 hours. This was followed by a post-fixation with 1% osmium tetroxide for 1 hour. Afterwards, the tissue pieces were dehydrated with ethanol, and embedded in Durcupan ACM. The samples were evaluated qualitatively based on the images recorded on a Hitachi 7100 electron microscope. The results of the test are given in Table 3. TABLE 3 Electron microscopic examination of the compounds of the invention on the thoracic aorta of SH rats (morphological testing) Materials Degree of Doses regeneration SH control, physiological saline solution 1 Compound no. 4., 20 mg/kg p. o. 5 Compound no. 8., 5 mg/kg p. o. 5 Compound no. 9., 5 mg/kg p. o. 5 Compound no. 11., 10 mg/kg p. o. 4 Compound no. 12., 20 mg/kg p. o. 3 Compound no. 13., 20 mg/kg p. o. 4 The results of the morphological test are expressed on a scale of 1 to 5, depending upon the degree to which the treatment with various test compounds restored the hypertonia-induced endothelium damage, that is, upon the degree of regeneration activity observed. On the scale, 1 was used to refer to cases where no regeneration was observable, 2 refers to weak, 3 to average, 4 to good, and 5 to strong regeneration. When comparing it to the untreated control, significant protective and regenerative effect was observed after treatment with the compounds of the invention. Due to the treatment, a thin, freshly formed layer covered the wounded sub-endothelium, which contained cells with active nuclei and rich cytoplasm. Regeneration was shown to be very effective in the case of the majority of the tested molecules. Compounds of general formulae (I) where Y is a halogen atom are prepared by halogenating the suitable compound containing a hydroxyl group as Y substituent. The other compounds of the invention are prepared by the known method, according to the procedures given in WO 97/16439 and WO 98/06400. Methods for the preparation of certain compounds are demonstrated in the examples. The subject invention also concerns methods for treating or preventing vascular diseases or diseases related to vascular disorders comprising administering an effective amount of a compound or pharmaceutical composition of the invention to a patient in need thereof. The compositions of the invention can be made in solid or liquid forms generally used in human and veterinary therapy. For oral administration tablets, coated tablets, dragees, granules, capsules, solutions or syrups, for rectal administration suppositories, and for parenteral administration lyophylised or not lyophylised injections or infusion solutions can be prepared by known preparation methods. The oral compositions may contain fillers such as microcrystalline cellulose, starch, lactose, lubricants, such as stearic acid and magnesium stearate, coating materials such as sugar, film materials such as hydroxymethyl cellulose, flavors or sweeteners such as methyl paraben or saccharine, and colorants. Auxiliaries in the suppositories may be for example cocoa butter and polyethylene glycol. The compositions for parenteral use may contain saline or optional dispersing and wetting agents such as propylene glycol along with the active ingredient. The dose of the compounds of the invention depends on the illness of the patient and the disease and varies from 0.1 to 200 mg/kg/day, preferably from 0.1 to 50 mg/kg/day. For human therapy, the preferable oral dose is 10-200 mg, in case of rectal administration 1-15 mg, and in case of parenteral treatment 2-20 mg daily for adults. These doses are applied in unit dosage forms optionally distributed to 2-3 administrations, particularly in case of oral treatment. All patents, patent applications, provisional applications, and publications referred to or cited herein, including Hungarian application Serial Nos. PO200109 and PO204362, are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification. The invention is demonstrated by the examples below. These examples should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted. EXAMPLE 1 N-[3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamidine 1.86 g (0.033 mol) of KOH is dissolved in a mixture of 10 ml ethanol and 75 ml methanol. To the solution 4.59 g (0.03 mol) of nicotinamidoxime-1-oxide is added. After stirring for 15 minutes, a solution of 4.85 g (0.03 mol) of 1-chloro-3-(1-piperidinyl)-propane in 6 ml ethanol is added. The mixture is boiled for 12 hours, then the precipitate is filtered off, and the solution is evaporated. To the residue 30 ml of 2 N potassium carbonate solution is added, then extracted 3 times with 50 ml of chloroform. The organic phase is washed with 15 ml of 2 N potassium carbonate solution, dried over anhydrous magnesium sulfate, filtered and evaporated. The crude product is triturated with 40 ml tert.butyl-methyl-ether. This procedure is repeated, and the product obtained in the two steps is recrystallized in a 1:2 mixture of methanol and diethylether. Yield: 1.72 g (21%). 1H-NMR (methanol d4): 8.62; 8.36; 7.82; 7.58; 4.22; 2.3-2.6; 1.92; 1.3-1.6. 13C-NMR (methanol d4: 149.4; 140.9; 138.0; 134.5; 127.9; 73.3; 57.4; 55.6; 27.4; 26.7; 25.4. EXAMPLE 2 N-(3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboximidoyl chloride 1.668 g (6.0 mmol) of N-[3-(1-piperidinyl)-propoxy]-pyridin-1-oxide-3-carboxamidine is dissolved in a 1:1 mixture of cc. HCl and water, then at 0° C. added dropwise to a solution of 0.57 g (8.2 mmol) of NaNO2 in 4 ml of water. The mixture is stirred for 2 hours at 0° C., then basified with 15 ml of 20% NaOH solution. It is then extracted three times with 15 ml of chloroform, the extract is dried over anhydrous sodium sulfate, filtered and evaporated. The residue is triturated with 15 ml of ether, filtered and dried. The precipitate is recrystallized from 6 ml of acetone. Yield: 1.1 g (63%). 1H-NMR (DMSO d6): 8.56; 8.20; 7.98; 7.48; 2.4-2.6; 1.92; 1.45; 1.3. 13C-NMR (DMSO d6): 139.6; 136.7; 132.9; 132.3; 129.5 and 126.5; 73.6; 53.9; 52.9; 24.1; 23.5; 22.0. EXAMPLE 3 N-[2-hydroxy-3-(1-piperidinyl)propoxy]-N′-n-butyl-pyridin-1-oxide-4-carboxamidine 1.18 g of N-[2-hydroxy-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-4-carboximidoyl chloride is dissolved in a mixture of 18 ml of n-butylamine and 10 ml of 2-methoxyethyl-ether. The reaction mixture is heated under reflux for 24 hours. The n-butylamine is evaporated from the mixture, and to the residue 100 ml of 2 M potassium carbonate solution is added, then it is extracted 3 times with 10 ml of chloroform. The extract is dried over anhydrous sodium sulfate, filtered and evaporated. The obtained material is recrystallized form ethylacetate. Yield: 0.85 g (64%). 1H-NMR (CDCl3): 8.18; 7.36; 5.22; 4.06; 4.04; 2.97; 2.62 and 2.42; 1.2-1.7; 0.86. 13C-NMR (CDCl3): 153.1; 139.2; 129.2; 125.5; 76.4; 65.5; 60.8; 54.6; 43.9; 33.3; 25.6; 23.9; 19.6; 13.6. EXAMPLE 4 N-[3-(1-oxido-1-piperidinyl)propoxy]-3-nitro-benzimidoyl-chloride dihydrate To a solution of 1.0 g (3.0 mmol) of N-[3-(1-piperidinyl)propoxy]-3-nitro-benzimidoyl-chloride in 5 ml of chloroform a solution of 0.725 g (4.2 mmol) of m-chloroperbenzoic acid in 6 ml of chloroform is added. The reaction mixture is stirred for 6 hours at 25° C., then evaporated. To the residue 12 ml of 2 M potassium carbonate solution is added, and extracted 5 times with 20 ml of chloroform. The combined extracts are dried over magnesium sulfate, filtered and evaporated. The product is dissolved in ethanol; the solution is treated with charcoal then evaporated. The obtained material is triturated with ethylacetate, filtered and dried. Yield: 0.74 g (63%). 1H-NMR (CDCl3): 8.62; 8.28; 8.18; 7.58; 4.52; 3.1-3.6; 2.2-2.6; 1.3-1.8. 13C-NMR (CDCl3): 148.2; 135.9; 134.0; 132.7; 129.6; 125.0; 122.0; 73.7; 67.0; 65.4; 22.4; 22.1; 20.9. EXAMPLE 5 2-chloro-N-(3-(4-oxido-4-morfolinyl)propoxyl-benzimidoyl chloride Proceed according to Example 4. with the difference that as starting material 2-chloro-N-[3-(4-morfolinyl)-propoxy]-benzimidoyl-chloride is used. Yield: 82%. EXAMPLE 6 (R,S)-5,6-dihydro-5-[(1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine a) 18.5 g (0.05 mol) of N-[2-hydroxy-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamidine-hydrochloride is dissolved in 50 ml of thionylchloride, and the reaction mixture is heated under reflux for 1 hour. Next the reaction mixture is evaporated, the residue is dissolved in methanol, and the solution is treated with charcoal, filtered and evaporated. The residue is crystallized from a minimum quantity of ethanol. The yield of the obtained N-[2-chloro-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamidine hydrochloride intermediate is 68%. b) To a solution of 16.5 g (143.5 mmol) of potassium-tert.butylate in 150 ml of tert.butanol 11.8 g (34.1 mmol) N-[2-chloro-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamidine hydrochloride intermediate is added. The reaction mixture is boiled for 5 hours, then evaporated. To the evaporation residue 100 ml of 5% NaOH solution is added, and the mixture is extracted 3 times with 300 ml of ethylacetate. The combined extracts are dried over sodium-sulfate, filtered and evaporated. The evaporation residue is triturated with ether, filtered, washed with ether and dried. Yield: 34%. Mp.: 154-158° C. EXAMPLE 7 5,6-dihydro-5-[(4-benzyl-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine Proceed according to Example 6., starting form the corresponding chlorinated amidine-compound. Yield: 20% Mp.: 178-180° C. EXAMPLE 8 (R) or (S)-5,6-dihydro-5-[(2-oxo-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine 2.5 g (9.6 mmol) of (−)-5,6-dihydro-5-(1-piperidinyl)-methyl-3-(3-pyridyl)-4H-1,2,4-oxadiazine is dissolved in 150 ml of 1% acetic acid, and to the solution 17.86 g (47.99 mmol) of ethylenediamine-tetraacetic acid disodium salt dihydrate, and 15.3 g (48 mmol) mercury(II)-acetate is added, and the reaction mixture is boiled for 2 hours while stirring. Then the reaction mixture is filtered, the filtrate is evaporated, to the residue 500 ml of methanol, and then in small portions 17.5 g (0.46 mol) sodium-[tetrahydrido-borate(III)] is added while stirring. After addition of the borohydride its excess is decomposed with 1:1 aqueous hydrochloric acid (pH=3), then the pH of the reaction mixture is set to 10 with 10% NaOH solution. The methanol is evaporated from the reaction mixture, and then the aqueous phase is extracted 3 times with 150 ml of chloroform. The combined chloroform phases are washed first with 100 ml of water, then with 50 ml of brine, the organic phase is dried over magnesium-sulfate, filtered and evaporated. The obtained oil (2 g) is purified by column chromatography (Kieselgel 60, eluent: 1:1 mixture of chloroform and methanol), and crystallized with a mixture of ethylacetate and ether (by the addition of very little amount of ethanol). 0.94 g (35.7%) pure material is obtained. 1H-NMR: (CDCl3): 8.9; 8.6; 7.92; 7.26; 6.68; 3.98; 3.96; 3.72-3.6; 3.42-3.22; 2.30; 1.76. 13C-NMR (CDCl3): 172.2; 150.8; 150.4; 146.9; 133.2; 128.6; 123.3; 65.1; 50.7; 50.5; 50.0; 32.1; 20.9. EXAMPLE 9 (+)-5,6-dihydro-5-[(1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine 6.25 g (24 mmol) of (−)-5,6-dihydro-5-(1-piperidinyl)-methyl-3-(3-pyridyl)-4H-1,2,4-oxadiazine is dissolved in a mixture of 40 ml of water, 6.85 ml (120 mmol) of glacial acetic acid and 1.43 ml (24 mmol) of cc. H2SO4. The solution is heated to 60° C., and at this temperature 12 ml (75 mmol) of 21.5% hydrogen peroxide is added dropwise, and the reaction mixture is kept on stirring at this temperature. After 10 hours to the reaction mixture further 6 ml of 21.5% hydrogen peroxide is added dropwise. After another 20 hours the reaction mixture is cooled to 0° C., and it is introduced dropwise into 60 ml of 0° C. 20% NaOH, then extracted 5 times with 50 ml of dichloromethane. The combined organic phases are washed with water, dried over magnesium-sulfate and evaporated. The evaporation residue is purified by column chromatography. The suitable fractions are triturated with 20 ml of acetone and kept in refrigerator overnight. Next day the product is filtered, washed with cold acetone and dried, then recrystallized from ethanol-ethylacetate. Yield: 13.7%. Mp.: 165-168° C. EXAMPLE 10 (R) or (S)-5,6-dihydro-5-[(1-oxido-1-piperidinyl)methyl]-3-(1-oxido-3-pyridyl)-4H-1,2,4-oxadiazine Proceed according to Example 9. with the difference that the suitable column chromatographic fraction is isolated. Yield: 3.4%. 1H-NMR (D2O): 8.38; 8.26; 7.76; 7.53; 4.6; 4.4; 3.9; 3.55-3.1; 1.95-1.25. 13C-NMR (D2O): 149.7; 139.9; 136.7; 131.6; 129.1; 126.9; 69.2; 65.6; 65.5; 44.3; 20.46; 20.30 and 20.17. EXAMPLE 11 5,6-dihydro-5-[(4-hydroxy-1-piperidinyl)methyl]-3-(3-pyridyl)-4H-1,2,4-oxadiazine 20.55 g (150 mmol) of 3-pyridin-amidoxime and 20.1 g (360 mmol) of potassium hydroxide are dissolved in 95 ml of water and 28.5 ml of DMSO, then cooled to 0° C. At this temperature 20.85 g (17.7 ml, 225 mmol) of epichlorohydrine is added dropwise and the mixture is stirred for 3 hours. It is then extracted with 6×50 ml of ether, the combined organic phases are washed with 50 ml brine, dried over Na2SO4, treated with charcoal, filtered and evaporated. m=6.08 g (21%) The obtained evaporation residue is taken up in 90 ml of ether, the clear solution is decanted from the tar (1.18 g)—the ethereal solution contains 24.8 mmol epoxy compound—and to this solution 5.1 g (24.8 mmol) of 4-benzoyloxy-piperidine dissolved in 20 ml of iso-propanol is added. It is stirred at room temperature for 6 days, then the small amount of precipitate is filtered off, and the mother liquor is evaporated. The obtained 11.7 g of evaporation residue is taken up in 100 ml of water, extracted with 100 ml of ether, then 2×50 ml of ethylacetate, the organic phases are dried over Na2SO4 and evaporated. m=8.77 g (88%) Formation of monohydrochloride: 8.77 g of evaporation residue is dissolved in 44 ml iso-propanol (with slight heating), then 3.72 ml of 6M HCl/iPA is added. Upon heating the solution to boiling point, the separated gum dissolves. When it is then cooled back to room temperature, the monohydrochloride nicely precipitates. It is crystallized in a refrigerator for a few hours, then filtered off, and washed with cold iPA. m=7.19 g (75.4%) Mp.: 115-120° C. Recrystallization: 7.19 g crude product form 150 ml of hot iso-propanol. Crystallizes upon cooling. m=5.87 mg (81.5%) Mp.: 117-120° C. 5.87 g (13.5 mmol) of this monohydrochloride is suspended in 60 ml of dichloroethane, 30 ml of thionylchloride is added and is boiled for 1 hour. It is then cooled back to room temperature, 220 ml of methanol is added dropwise, treated with charcoal, filtered and evaporated. The obtained 7.5 g evaporation residue is triturated with 75 ml of ethylacetate, and crystallized by cooling. Filtered, washed with cold ethylacetate, then the wet precipitate is stirred with 50 ml of acetone. The precipitate is filtered off, and washed with acetone. m=5.76 g (87%) 5.76 g (11.75 mmol) of this “chloro-compound” is suspended in 120 ml of tert.butanol, 8.12 g (72.37 mmol) of potassium-tert.butylate is added and boiled for 1 hour. The precipitate is filtered and washed with a small amount of methanol, and the mother liquor is evaporated. The obtained 8.56 g of evaporation residue is taken up in 40 ml of water, extracted with 2×30 ml of chloroform, dried and evaporated. The residue (m=1.89 g) is triturated with 20 ml of ethylacetate, crystallized by cooling, filtered off, and washed with EtOAc. m=1.19 g Recrystallization: 1.19 mg of crude product from 13 ml of hot iso-propanol. Crystallizes upon cooling. m=605 mg Mp.: 170-173° C. 1H-NMR (the examined sample: PM-720-cs5; solvent: CDCI3+DMSO; reference: CDCI3 MHz:300) [ppm]: 8.8 8.5 7.9 7.3 (m,4H,aromatic protons); 6.1 (m,1H,NH); 4.02 (m,1H,OCH2); 3.74 (m,1H,CH); 3.62 (m,1H,CH—OH); 3.5 (m,1H,OCH2); 2.9-2.3 (m,6H,3×CH2N); 1.9-1.52 (m,4H,2×CH2); 13C-NMR (the examined sample: PM-720-cs5; solvent: CDCI3+DMSO; reference: CDCI3 MHz:75.4) [ppm]: 150.4 (C═N); 150.9 146.9 133.5 128.6 123.3 (5C, Pyr-carbon atoms); 66.6 (OCH2); 66.4 (CH—OH); 59.4 (CH2N); 51.8 (CH2N); 50.7 (CH2N); 46.3 (CHN); 33.8 (2C, 2×CH2). EXAMPLE 12 N-[2-chloro-3-(1-piperidinyl)propoxy]-3-benzimidoyl-chloride hydrochloride 2.0 g of N-[2-hydroxy-3-(1-piperidinyl)propoxy]-benzimidoyl-chloride hydrochloride is dissolved in 10 ml of thionylchloride, then the solution is boiled for 2 hours. The thionylchloride is distilled off; the evaporation residue is taken up in 50 ml of methanol, then evaporated. The light yellow evaporation residue (m=2.48 g) is dissolved in 12.5 ml of ethanol and crystallized with 50 ml of ether. The separated precipitate is filtered off, and washed with a mixture of ethanol/ether. m=1.68 g Mp.: 154.5-1 58° C. Recrystallization: by dissolving 320 mg in 1 ml warm MeOH, then precipitating with 3 ml of ether. The separated precipitate is filtered off and washed. m=210 mg Mp.: 155.5-160° C. (corr.) EXAMPLE 13 N-[2-hydroxy-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboxamide 4.0 g of N-[2-hydroxy-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3-carboximidoyl-chloride is stirred in 120 ml of 0.2 n NaOH at 60° C. for 5 days. The solution is neutralized with aqueous hydrochloric acid, evaporated, the residue is triturated with ethanol, and the obtained solution is evaporated again. The residue is crystallized with isopropanol, filtered off, and the obtained 1.0 g crude product is recrystallized from boiling isopropanol. Yield: 0.8 g Mp.: 143-147° C. EXAMPLE 14 Tablets (+)-5,6-dihydro-5-[(1-piperidinyl)-methyl-3- 20.0 mg (3-pyridyl)--4H-1,2,4-oxadiazine corn starch 100.0 mg lactose 95.0 mg talc 4.5 mg magnesium stearate 0.5 mg The active compound is finely ground, mixed with the excipients, the mixture is homogenized and granulated. The granulate is pressed into tablets. EXAMPLE 15 Capsules 5,6-dihydro-5-[(1-piperidinyl)-methyl-3- 20.0 mg (3-pyridyl)--4H-1,2,4-oxadiazine microcrystalline cellulose 99.0 mg amorphous silica 1.0 mg The active ingredient is mixed with the additives, the mixture is homogenized and filled into gelatine capsules. EXAMPLE 16 Dragées N-[3-(1-oxido-1-piperidinyl)propoxy]-3- 25.0 mg nitro-benzimidoyl-chloride dihydrate lactose 82.5 mg potato starch 33.0 mg polyvinyl pyrrolidone 4.0 mg magnesium stearate 0.5 mg The active ingredient and the polyvinyl pyrrolidone are dissolved in ethanol. The lactose and the potato starch are mixed, and the mixture is evenly wetted with the granulating solution of the active ingredient. After sieving, the wet granulate it is dried at 50° C. and sieved. Magnesium stearate is added and the granulate is pressed into dragee cores, which are then coated with sugar and polished with bee wax. EXAMPLE 17 Suppositories 5,6-dihydro-5-[(4-benzyl-1-piperidinyl)-methyl]-3- 4.0 mg (3-pyridyl)--4H-1,2,4-oxadiazine cocoa butter 3.5 g solid fat 50 suppository mass 15.0 g The cocoa butter and the suppository mass are heated to 40° C., the active ingredient is dispersed in the melt, then the mass is cast into suppository forms. EXAMPLE 18 Solution 5,6-dihydro-5-[(4-hydroxy-1-piperidinyl)methyl]- 500 mg 3-(3-pyridyl)-4H-1,2,4-oxadiazine hydrochloride sorbite 10 g saccharin sodium 0.05 g twice distilled water q.s. ad 100 ml EXAMPLE 19 Injection N-[2-chloro-3-(1-piperidinyl)propoxy]-3- 2 mg benzimidoyl-chloride hydrochloride physiological saline solution, 2.0 ml pyrogen-free, sterile q.s. ad The solution is filled into 2 ml vials and the vials are sealed. EXAMPLE 20 Infusion solution Infusion solution of 500 ml volume is prepared with the following composition: N-[2-hydroxy-3-(1-piperidinyl)propoxy]-pyridin-1-oxide-3- 20 mg carboxamide methanesulfonate physiological saline solution, pyrogen-free, sterile q.s. ad 500 ml It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application. | 20040712 | 20080422 | 20050224 | 98087.0 | 1 | HABTE, KAHSAY | PHARMACEUTICALLY EFFECTIVE COMPOUNDS | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,889,974 | ACCEPTED | Magic-themed adventure game | A method of interactive game play is provided wherein a seemingly magical wand toy is provided for enabling a trained user to electronically send and receive information to and from other wand toys, a master system and/or to actuate various play effects within a play environment. The toy wand or other seemingly magical object is configured to use a send/received radio frequency communications protocol which provides a basic foundation for a complex, interactive entertainment system to create a seemingly magical interactive play experience. | 1. A magic-themed game for amusing and entertaining one or more game participants, comprising: one or more wand devices for facilitating storage and retrieval of selected information pertaining to individual game participants and/or groups of game participants playing the game, said wand devices being sized and adapted to be transported by each game participant and/or group of game participants while playing said game; one or more reader devices adapted to retrieve said stored information from each said wand device; at least one interactive gaming effect adapted to communicate with one or more of said reader devices and to produce a first result if a predetermined set of conditions represented by said stored information is satisfied and to produce a second result if the predetermined set of conditions is not satisfied; whereby game participants and/or groups of game participants are encouraged to play said game to produce either said first or second result as desired. 2. The interactive game of claim 1 wherein at least one of said wand devices comprises a radio-frequency transmitter. 3. The interactive game of claim 1 wherein said at least one wand device comprises an RFID tag. 4. An interactive game for amusing and entertaining one or more game participants, comprising: one or more transponder devices for facilitating storage and retrieval of selected information pertaining to individual game participants and/or groups of game participants playing the game, said transponder devices being sized and adapted to be worn and/or otherwise transported by each game participant and/or group of game participants while playing said game; one or more reader devices adapted to retrieve said stored information from each said transponder device; one or more writer devices adapted to selectively update and/or modify said stored information on each said transponder device in accordance with the completion by game participants and/or groups of game participants of one or more defined gaming sequences or protocols; at least one interactive gaming effect adapted to communicate with one or more of said reader devices and to produce a first result if a first set of conditions represented by said stored information is satisfied and to produce a second result if a second set of conditions represented by said stored information is satisfied; whereby game participants and/or groups of game participants are encouraged to complete said defined gaming sequences or protocols in order to produce the necessary stored information to satisfy either said first or second set of conditions and thereby produce either said first or second result as desired. 5. The interactive game of claim 4 wherein at least one of said transponder devices comprises a radio-frequency transmitter. 6. The interactive game of claim 5 wherein said at least one transponder device comprises an RFID tag. 7. The interactive game of claim 6 wherein said RFID tag is configured to operate at one or more of the following frequencies: 134.2 kHz, 123.2 kHz or 13.56 mHz. 8. The interactive game of claim 6 wherein said RFID tag comprises a 13.56 mHz read/write label tag. 9. The interactive game of claim 6 wherein said RFID tag comprises a 134.2 kHz and/or 123.2 kHz, 23 mm glass transponder. 10. The interactive game of claim 5 wherein said at least one transponder device is configured and adapted to use a send/receive radio frequency communication protocol. 11. The interactive game of claim 4 wherein at least one of said transponder devices comprises an infrared LED transmitter. 12. The interactive game of claim 4 wherein said one or more transponder devices are adapted to utilize one or more wireless communication protocols selected from the group consisting of infrared-, digital-, analog, magnetic, AM/FM-, laser-, visual-, audio-, and/or ultrasonic. 13. The interactive game of claim 4 wherein said one or more transponder devices are embodied in a portable structure comprising one or more of the following: identification badge, trading card, collectible sports card, role-play character card, book mark, necklace, pendant, key-chain, trinket, token and/or wand. 14. The interactive game of claim 4 wherein each said transponder device is adapted to store certain information uniquely identifying one or more game participants and/or group of game participants. 15. The interactive game of claim 14 wherein said stored information includes one or more unique identification numbers. 16. The interactive game of claim 14 wherein said stored information includes one or more of the following: name, age, address, phone number, fax number, internet address, e-mail address. 17. The interactive game of claim 4 wherein each said transponder device is adapted to store information representing points scored and/or levels achieved by each game participant and/or group of game participants. 18. The interactive game of claim 4 wherein said one or more reader devices and/or said writer devices are configured to operate at one or more of the following frequencies: 134.2 kHz, 123.2 kHz or 13.56 mHz. 19. The interactive game of claim 4 wherein at least one of said one or more reader devices and said one or more writer devices comprise a single integral reader/writer device. 20. The interactive game of claim 4 wherein said defined gaming sequence comprises one or more of the following elements: role playing, reading, memory stimulation, tactile coordination. 21. The interactive game of claim 4 wherein said defined gaming sequence requires a group of game participants to work together. 22. The interactive game of claim 4 wherein said interactive gaming effect comprises awarding a game participant with additional gaming points, game levels and/or rank. 23. The interactive game of claim 4 wherein said game comprises a role play game using an imaginary game character and wherein said interactive gaming effect comprises awarding certain enhanced attributes to said game character. 24. The interactive game of claim 23 wherein said enhanced attributes comprise one or more of the following: magic skill level, magic strength, flight ability, spell-casting abilities. 25. The interactive game of claim 4 wherein said game comprises a role-play fantasy character game and wherein said one or more transponder devices comprise electronically readable role-play cards comprising a paper, cardboard or plastic substrate having a front side and a back side, the front side being imprinted with graphics, photos, or other information representative of a desired role-play character, the back side having affixed thereon an RF tag programmable to contain certain character attributes and whereby the stored character attributes may be easily and conveniently transported to RF-equipped play facilities, computer games, video games, home game consoles, and/or hand-held game units. 26. The interactive game of claim 4 wherein said game comprises a collectible trading card game and wherein said one or more transponder devices comprise electronically readable trading cards depicting various real or imaginary persons, characters and/or objects and wherein each card has recorded or stored thereon in an electronically readable format certain selected information pertaining to the particular person, character or object, such as performance statistics, traits/powers, or special abilities, the information being stored on an RFID tracking tag associated with each card and which can be read electronically and wirelessly over a predetermined range greater than about 1 cm when placed in the proximity of one or more of said reader devices. 27. The interactive game of claim 4 wherein said interactive gaming effect comprises an access control device and wherein said first result comprises allowing access by one or more game participants to a particular defined play station area or zone and wherein said second result comprises denying access by one or more game participants to said defined play station area or zone. 28. The interactive game of claim 27 wherein said defined play station area or zone comprises one or more of the following: play area within a play structure, game level within a computer gaming platform, home game console, arcade game console, video game, hand-held game device, or internet gaming device. 29. The interactive game of claim 4 wherein said interactive gaming effect comprises selectively actuating one or more of the following: projectile accelerators, cannons, interactive targets, fountains, geysers, cranes, filter relays, lighting, sound, mechanical actuators, or pneumatic actuators. 30. The interactive game of claim 4 wherein said reader devices and said writer devices are distributed throughout a gaming facility and wherein said game is carried out within said facility. 31. The interactive game of claim 30 wherein said gaming facility comprises an amusement park, family entertainment center, restaurant, arcade or amusement center 32. The interactive game of claim 31 wherein said transponder device comprises a wireless actuator device configured and adapted to enable a game participant to electronically and wirelessly actuate one or more of said interactive gaming effects to create a seemingly magical play experience. 33. The interactive game of claim 4 wherein said reader devices and said writer devices are operatively associated with one or more of the following: entertainment center, television, video, radio, computer software program, game console, or web site. 34. The interactive game of claim 33 further comprising a wireless actuator device or wand configured and adapted to enable a game participant to electronically and wirelessly actuate one or more of said interactive gaming effects to create a seemingly magical play experience. 35. The interactive game of claim 34 wherein said wireless actuator device or wand comprises one or more combination wheels having various symbols and/or images thereon which may be rotated to produce a desired pattern of symbols for actuating a particular interactive gaming effect. 36. A game for amusing and entertaining one or more game participants within a play facility, comprising: one or more wand devices for facilitating storage and retrieval of selected information pertaining to individual game participants and/or groups of game participants playing the game, said wand devices being sized and adapted to be transported by each game participant and/or group of game participants while playing said game; one or more reader devices distributed throughout said play facility and adapted to retrieve said stored information from each said wand device when in proximity thereof; one or more writer devices adapted to selectively update and/or modify said stored information on each said wand device in accordance with the completion by game participants and/or groups of game participants of one or more defined gaming sequences or protocols; at least one interactive gaming effect associated with one or more of said reader devices and to produce a first result if a first set of conditions represented by said stored information is satisfied and to produce a second result if a second set of conditions represented by said stored information is satisfied. 37. The game of claim 36 wherein said one or more wand devices comprises a radio-frequency transmitter. 38. The game of claim 36 wherein said one or more wand devices comprises an RFID tag. 39. The game of claim 38 wherein said RFID tag comprises a radio-frequency transceiver configured to operate at one or more of the following frequencies: 134.2 kHz, 123.2 kHz or 13.56 mHz. 40. The game of claim 36 wherein said wand comprises an elongated rod having an RFID tag transponder at the tip thereof which game participants may selectively bring into proximity with one or more of said reader devices to actuate an associated gaming effect. 41. The game of claim 40 wherein said RFID tag comprises 134.2 kHz and/or 123.2 kHz, 23 mm glass transponder. 42. The game of claim 36 wherein said wand device further comprises one or more infrared LED transmitters. 43. The game of claim 36 further comprising one or more transponder devices embodied in a portable structure comprising one or more of the following: identification badge, trading card, collectible sports card, role-play character card, book mark, necklace, pendant, key-chain, trinket, and/or token. 44. The game of claim 36 wherein each wand device is adapted to store certain information uniquely identifying one or more game participants and/or group of game participants. 45. The game of claim 44 wherein said stored information includes one or more unique identification numbers. 46. The game of claim 44 wherein said stored information includes one or more of the following: name, age, address, phone number, fax number, internet address, e-mail address. 47. The game of claim 36 wherein each said wand device is adapted to store information representing points scored and/or levels achieved by each game participant and/or group of game participants. 48. The game of claim 36 wherein said defined gaming sequence comprises one or more of the following elements: role playing, reading, memory stimulation, tactile coordination. 49. The game of claim 36 wherein said defined gaming sequence requires a group of game participants to work together to achieve a common goal. 50. The game of claim 36 wherein said interactive gaming effect comprises rewarding a game participant with additional gaming points, game levels and/or ranks. 51. The game of claim 36 wherein said game comprises a role play game using an imaginary game character and wherein said interactive gaming effect comprises awarding certain enhanced attributes to said game character. 52. The game of claim 51 wherein said enhanced attributes comprise one or more of the following: magic skill level, magic strength, flight ability, spell-casting abilities. 53. The game of claim 36 wherein said game comprises a role-play fantasy character game and wherein said game further comprises one or more electronically readable role-play cards comprising a paper, cardboard or plastic substrate having a front side and a back side, the front side being imprinted with graphics, photos, or other information representative of a desired role-play character, the back side having affixed thereon an RF tag programmable to contain certain character attributes and whereby the stored character attributes may be transported to RF-equipped play facilities, computer games, video games, home game consoles, and/or hand-held game units. 54. The game of claim 36 wherein said game comprises a collectible trading card game and wherein said game further comprises one or more electronically readable trading cards depicting various real or imaginary persons, characters and/or objects and wherein each card has recorded or stored thereon in an electronically readable format certain selected information pertaining to the particular person, character or object, such as performance statistics, traits/powers, or special abilities, the information being stored on an RFID tracking tag associated with each card and which can be read electronically and wirelessly over a predetermined range greater than about 1 cm when placed in the proximity of said one or more of said reader devices. 55. The game of claim 36 wherein said interactive gaming effect comprises an access control device wherein said first result comprises allowing access by one or more game participants to a play station area or zone and wherein said second result comprises denying access by one or more game participants to said defined play station area or zone. 56. The game of claim 36 wherein said interactive gaming effect comprises selectively actuating one or more of the following: projectile accelerators, cannons, interactive targets, fountains, geysers, cranes, filter relays, lighting, sound, mechanical actuators, or pneumatic actuators. 57. The game of claim 36 wherein said gaming facility comprises an amusement park, family entertainment center, restaurant, arcade or amusement center 58. The game of claim 36 wherein said reader devices and said writer devices are operatively associated with one or more of the following: entertainment center, television, video, radio, computer software program, game console, or web site. 59. The game of claim 36 wherein each said wand device further comprises one or more combination wheels having various symbols and/or images thereon which may be rotated by game participants to produce a desired pattern of symbols. 60. A fantasy role-play game for amusing and entertaining one or more game participants, comprising: one or more role-play fantasy character cards comprising a substrate having a front side and a back side, the front side being imprinted with graphics, photos, and/or other information representative of a desired role-play character, the back side or front side having affixed thereon or embedded therein an electronically-readable information storage device programmable to contain certain stored information pertaining to selected character attributes, game character developments, and/or game participant information; a reader device associated with one or more gaming platforms and adapted and configured to retrieve said stored information from each said character card and to communicate said information to said gaming platform; whereby said gaming platform is thereby able to uniquely modify a selected gaming experience based on the information stored on each said role-play card. 61. The fantasy role-play game of claim 60 further comprising a writer device adapted to selectively update and/or modify said stored information on each said character card in accordance with the completion by game participants and/or groups of game participants of one or more defined gaming sequences or protocols. 62. The fantasy role-play game of claim 61 wherein said defined gaming sequence requires a group of game participants to work together. 63. The fantasy of role-play game of claim 60 wherein said gaming platform comprises one or more of the following: play facility, computer game, video game, home game console, hand-held game unit, play structure. 64. The fantasy role-play game of claim 60 wherein said information storage device comprises one or more of the following: radio-frequency transmitter, RFID tag, and/or magnetic strip. 65. The fantasy role-play game of claim 60 wherein said information storage device comprises and RFID tag configured to operate at one or more of the following frequencies: 134.2 kHz, 123.2 kHz or 13.56 mHz. 66. The fantasy role-play game of claim 65 wherein said RFID tag comprises a 13.56 mHz read/write label tag. 67. The fantasy role-play game of claim 60 wherein said information storage device has stored thereon information representing points scored and/or levels achieved by each game participant and/or group of game participants. 68. The fantasy role-play game of claim 60 wherein said information storage device has stored thereon information representing certain role-play character attributes comprising one or more of the following: magic skill level, magic strength, flight ability, spell-casting abilities. | RELATED APPLICATIONS This application claims priority to U.S. Utility application Ser. No. 09/792,282 filed Feb. 22, 2001, now U.S. Pat. No. 6,761,637, which application claims priority to provisional application Ser. No. 60/184,128, filed Feb. 22, 2000. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to children's' play toys and games and, in particular, to interactive toys, games and play systems utilizing radio frequency transponders and transceivers to provide a unique interactive game play experience. 2. Description of the Related Art Family entertainment centers, play structures and other similar facilities are well known for providing play and interaction among play participants playing in, or around an entertainment facility and/or play structure. See, for example, U.S. Pat. No. 5,853,332 to Briggs, incorporated herein by reference. A wide variety of commercially available play toys and games are also known for providing valuable learning and entertainment opportunities for children, such as role playing, reading, memory stimulation, tactile coordination and the like. However, there is always a demand for more exciting and entertaining games and toys that increase the learning and entertainment opportunities for children and stimulate creativity and imagination. SUMMARY OF THE INVENTION The present invention provides a unique method of game play carried out within either an existing or specially configured entertainment facility or play structure. The game utilizes an interactive “wand” and/or other tracking/actuation device to allow play participants to electronically and “magically” interact with their surrounding play environment(s). The play environment may either be real or imaginary (i.e. computer/TV generated), and either local or remote, as desired. Optionally, multiple play participants, each provided with a suitable “wand” and/or tracking device, may play and interact together, either within or outside the play environment, to achieve desired goals or produce desired effects within the play environment. In accordance with one embodiment the present invention provides an interactive play system and seemingly magical wand toy for enabling a trained user to electronically send and receive information to and from other wand toys and/or to and from various transceivers distributed throughout a play facility and/or connected to a master control system. The toy wand or other seemingly magical object is configured to use a send/receive radio frequency communication protocol which provides a basic foundation for a complex, interactive entertainment system to create a seemingly magic interactive play experience for play participants who possess and learn to use the magical wand toy. In accordance with another embodiment the present invention provides an interactive play structure in the theme of a “magic” training center for would-be wizards in accordance with the popular characters and storylines of the children's' book series “Harry Potter” by J. K Rowling. Within the play structure, play participants learn to use a “magic wand” and/or other tracking/actuation device. The wand allows play participants to electronically and “magically” interact with their surrounding play environment simply by pointing or using their wands in a particular manner to achieve desired goals or produce desired effects within the play environment. Various receivers or transceivers are distributed throughout the play structure to facilitate such interaction via wireless communications. In accordance with another embodiment the present invention provides a wand actuator device for actuating various interactive play effects within an RFID-compatible play environment. The wand comprises an elongated hollow pipe or tube having a proximal end or handle portion and a distal end or transmitting portion. An internal cavity may be provided to receive one or more batteries to power optional lighting, laser or sound effects and/or to power long-range transmissions such as via an infrared LED transmitter device or RF transmitter device. The distal end of the wand is fitted with an RFID (radio frequency identification device) transponder that is operable to provide relatively short-range RF communications (<60 cm) with one or more receivers or transceivers distributed throughout a play environment. The handle portion of the wand is fitted with optional combination wheels having various symbols and/or images thereon which may be rotated to produce a desired pattern of symbols required to operate the wand or achieve one or more special effects. In accordance with another embodiment the present invention provides an RFID card or badge intended to be affixed or adhered to the front of a shirt or blouse worn by a play participant while visiting an RF equipped play facility. The badge comprises a paper, cardboard or plastic substrate having a front side and a back side. The front side may be imprinted with graphics, photos, or any other information desired. The front side may include any number of other designs or information pertinent to its application. The obverse side of the badge contains certain electronics comprising a radio frequency tag pre-programmed with a unique person identifier number (“UPIN”). The UPIN may be used to identify and track individual play participants within the play facility. Optionally, each tag may also include a unique group identifier number (“UGIN”) which may be used to match a defined group of individuals having a predetermined relationship. In accordance with another embodiment the present invention provides an electronic role-play game utilizing specially configured electronically readable character cards. Each card is configured with an RFID or a magnetic “swipe” strip or the like, that may be used to store certain information describing the powers or abilities of an imaginary role-play character that the card represents. As each play participant uses his or her favorite character card in various play facilities the character represented by the card gains (or loses) certain attributes, such as magic skill level, magic strength, flight ability, various spell-casting abilities, etc. All of this information is preferably stored on the card so that the character attributes may be easily and conveniently transported to other similarly-equipped play facilities, computer games, video games, home game consoles, hand-held game units, and the like. In this manner, an imaginary role-play character is created and stored on a card that is able to seamlessly transcend from one play medium to the next. In accordance with another embodiment the present invention provides a trading card game wherein a plurality of cards depicting various real or imaginary persons, characters and/or objects are provided and wherein each card has recorded or stored thereon in an electronically readable format certain selected information pertaining to the particular person, character or object, such as performance statistics, traits/powers, or special abilities. The information is preferably stored on an RFID tracking tag associated with each card and which can be read electronically and wirelessly over a predetermined range preferably greater than about 1 cm when placed in the proximity of a suitably configured RF reader. Optionally, the RFID tag may be read/write capable such that it the information stored thereon may be changed or updated in any manner desired. Alternatively, a magnetic strip, bar code or similar information storage means may be used to store relevant information on the card. For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed. BRIEF DESCRIPTION OF THE DRAWINGS Having thus summarized the general nature of the invention and its essential features and advantages, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which: FIG. 1 is a perspective view of an interactive play structure modified to incorporate certain features and advantages in accordance with the present invention; FIG. 2A is a perspective view of a magic wand toy for use within the interactive play structure of FIG. 1 having features and advantages in accordance with the present invention; FIG. 2B is a partially exploded detail view of the proximal end or handle portion of the magic wand toy of FIG. 2A, illustrating the optional provision of combination wheels having features and advantages in accordance with the present invention; FIG. 2C is a partial cross-section detail view of the distal end or transmitting portion of the magic wand toy of FIG. 2A, illustrating the provision of an RF transponder device therein; FIG. 3 is a simplified schematic diagram of an RF reader and master control system for use with the magic wand toy actuator of FIG. 2A having features and advantages in accordance with the present invention; FIGS. 4A and 4B are front and rear views, respectively, of an optional RFID tracking badge or card for use within the interactive play structure of FIG. 1 having features and advantages in accordance with the present invention; FIGS. 5A and 5B are schematic diagrams illustrating typical operation of the RFID tracking badge of FIG. 4; FIG. 6 is simplified schematic diagram of an RFID read/write system for use with the RFID tracking badge of FIG. 4 having features and advantages in accordance with the present invention; FIG. 7 is a simplified block diagram illustrating the basic organization and function of the electronic circuitry comprising the RFID tag device of FIG. 4B; FIGS. 8A-8D are front views of various role-play character cards for use within an interactive play structure such as illustrated in FIG. 1; FIGS. 9A and 9B are front and rear views, respectively, of an alternative embodiment of a role-play character card for use with a specially configured interactive game and/or game play facility having features and advantages in accordance with the present invention; FIGS. 10A-G are various illustrations of a role-play adventure game configured to be utilized with the role-play character card of FIG. 9 and having features and advantages in accordance with the present invention; FIGS. 11A and 11B are front and rear views, respectively, of a trading or playing card having features and advantages in accordance with the present invention; and FIGS. 11C and 11D are front views of several alternative embodiments of trading or playing cards having features and advantages in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Basic System and Framework FIG. 1 illustrates one preferred embodiment of an interactive play structure 100 having features and advantages in accordance with the present invention. The particular play structure illustrated takes on the theme of a “magic” training center for would-be wizards in accordance with the popular characters and storylines of the children's' book series “Harry Potter” by J. K Rowling. Within this play structure 100, play participants 105 learn to use a “magic wand” 200 and/or other tracking/actuation device. The wand 200 allows play participants to electronically and “magically” interact with their surrounding play environment simply by pointing or using their wands in a particular manner to achieve desired goals or produce desired effects within the play environment. Various receivers or transceivers 300 are distributed throughout the play structure 100 to facilitate such interaction via wireless communications. Depending upon the degree of game complexity desired and the amount of information sharing required, the transceivers 300 may or may not be connected to a master system or central server (not shown). Preferably, most, if not all, of the receivers or transceivers 300 are stand-alone devices that do not require communications with an external server or network. In one particularly preferred embodiment this may be achieved by storing any information required to be shared on the wand 200 and/or on an associated radio frequency tracking card or badge worn or carried by the play participant (described later). The play structure itself comprises a multi-level structure constructed using any one of an number of materials and construction techniques well known to those skilled in the art. The structure 100 may be suitable for either outdoor or indoor use, as desired. Preferably, the structure 100 comprises a supporting framework 102 formed from a plurality of interconnected support members 126, comprising columns, pylons, beams, connectors and the like. The support members 126 may be formed from any combination of convenient materials having sufficient strength and durability for safely supporting multiple play participants 105. For example, plastic or PVC pipes, steel pipes, I-beams or channel beams, reinforced concrete beams/columns, and the like may all be used to form the supporting framework 102. For visual appeal and added safety, optional decorative panels, railings 132 and/or roofing elements 130 may be provided, as desired, to shade play participants 105 from the sun (for outdoor play structures), to prevent play participants from falling off the structure 100, or to complement a particular desired theme of the play structure 100. For instance, in the preferred embodiment shown in FIG. 1, various roof elements 130 and railings 132 are provided for added safety and to complement the theme of Harry Potter's “Hogwart School for Wizards.” Decorative panels may be formed of wood, fiberglass or other reinforced fiber, PVC, aluminum, steel or a variety of other suitable materials, as desired. Corrosion-resistant materials are preferred, particularly if the play structure 100 is to be used outdoors. Of course, those skilled in the art will readily appreciate that a wide variety of other decorative or thematic elements may be incorporated into the overall design of the play structure 100 in order to provide added safety and/or to help convey a particular desired play theme. Preferably, a suitable play media, such as foam or rubber balls or similar objects, is provided for use throughout the structure to provide a tactile interactive play experience. A number of conduits 128 or other transport means are preferably provided throughout the framework 102 for transporting play media to and from the various play areas in the play structure 100. The conduits 128 may be formed from plastic hosing or PVC pipes joined together using commercially available fittings, as is well known in the art. Conduits 128 may also be formed from a wide variety of other suitable materials such as steel pipe, ceramic/clay pipe, or they may be formed as open channels and/or runners, as desired. Clear or colored/transparent plastic pipes having an inner diameter of about 2⅛″-6½″, and more preferably about 3-4″, are particularly preferred for aesthetic appeal and added excitement. Alternatively, larger or smaller diameter conduits 128 or conduits 128 having different colors or shapes may be used, as desired, to accommodate various sizes and shapes of balls or other play media 114. Play media 114 may be conveniently transported by use of pressurized air or other suitable means, as desired. Various participant-operated or “magically” actuated conveyors may also be employed to circulate balls or other play media 114 from one area of the structure 100 to another, as desired. The particular play structure shown in FIG. 1 utilizes thousands of soft foam balls as an interactive play medium 114. These may be manipulated by play participants using various interactive play elements to create desired effects. Balls may range in size from approximately 1″ to 12″ in diameter or larger, as desired, and are preferable about 2-½″ in diameter. Preferably, the balls are not so small as to present a choking hazard for young children. The majority of the balls may be the same size, or a mixture of ball sizes may be utilized, as desired. A few play elements, as described below, may utilize balls of a relatively large diameter (about 12″ or more). Certain play elements may use only certain sized balls, with filtering relays (not shown) in the conduits 128 permitting only certain sized balls to roll to certain play areas. A range of colors for the balls may also be used for visual appeal. Optionally, ball sizes and/or types may be color-coded as desired to indicate their use with particular play elements or in certain play zones and/or for facilitating their return to the proper areas when they are removed. Other suitable play media 114 may include, without limitation, foam, plastic or rubber balls and similarly formed articles such as cubes, plates, discs, tubes, cones, rubber or foam bullets/arrows, the present invention not being limited to any particular preferred play media. These may be used alone or in combination with one another. For instance, flying discs, such as Frisbees™, may be flung from one location on the play structure 100 while other play participants shoot at the discs using foam balls or suction-cup arrows. Wet or semi-wet play mediums, such as slime-like materials, snow, mud, squirt guns and/or water balloons may also used, as desired, to cool and entertain play participants. Durable plastic or rubber play media are preferable in an outdoor play structure where environmental exposure may prematurely destroy or degrade the quality of certain play mediums such as foam balls. The particular play media used is not particularly important for purposes of carrying out the invention and, optionally, may be omitted altogether, if desired. Various electronic interactive play elements are disposed in, on and/or around the play structure 100 to allow play participants 105 to create desired “magical” effects, as illustrated in FIG. 1. These may include interactive elements such as projectile accelerators, cannons, interactive targets, fountains, geysers, cranes, filter relays, and the like for amusing and entertaining play participants and/or for producing various desired visual, aural or tactile effects. These may be actuated manually by play participants or, more desirably, “magically” electronically by appropriately using the wand 200 in conjunction with one or more transceivers 300. Some interactive play elements may have simple immediate effects, while others may have complex and/or delayed effects. Some play elements may produce local effects while others may produce remote effects. Each play participant 105, or sometimes a group of play participants working together, preferably must experiment with the various play elements and using their magic wands in order to discover how to create the desired effect(s). Once one play participant figures it out, he or she can use the resulting play effect to surprise and entertain other play participants. Yet other play participants will observe the activity and will attempt to also figure it out in order to turn the tables on the next group. Repeated play on a particular play element can increase the participants' skills in accurately using the wand 200 to produce desired effects or increasing the size or range of such effects. Optionally, play participants can compete with one another using the various play elements to see which participant or group of participants can create bigger, longer, more accurate or more spectacular effects. A spherical, preferably clear, plastic relay 172 acts as a trap and/or filter selectively feeding play media 114 into a holding tank. This tank, in turn, provides play media 114 to the flexible hose 128. Dramatic visual effects are created as multi-colored balls and/or other play media 114 bounce around the interior of the relay 172 and are carried up through the spiraling conduit 128. The relay 172 may also be used to collect and/or filter play media 114 for further transmission along the various conduits 128 or to other play elements or conveyors as desired. Other interactive play elements may include, for example and without limitation, a wand activated overhead reservoir for dumping balls or other play media 114 onto other play participants, a tray or channel for allowing balls or other play media 114 to roll down onto a target or other play participants, a bucket conveyor for lifting balls or other play media 114 from a lower collection basin to an elevated container for supplying other play elements, and various interactive targets. The play structure 100 also preferably incorporates a number of other conventional (passive) play elements, such as climbing nets, crawl tunnels, swinging bridges, slides 110, and the like as shown in FIG. 1. These provide entertaining physical challenges and allow play participants to safely negotiate their way through the various areas of the play structure 100. Slides 110 may be provided at the front, rear, and/or sides of the play structure 100 and may be straight, curved, or spiral-shaped, as desired. They may also be enclosed and tube-like or open and exposed to flying play media, as desired. Alternatively, those skilled in the art will readily appreciate that the size, number, and location of the various slides 110 can be varied, as desired, while still enjoying the benefits and advantages of the present invention. Multiple ball pits and the like may also be provided at various locations throughout the play structure. Those skilled in the art will readily appreciate that a wide variety of other passive play elements, such as funny mirrors, rotating tunnels, trampolines, climbing bars, swings, etc. may all be used to create a desired play environment for carrying out the features and advantages as of the present invention as taught herein. While a particular preferred play environment and play structure 100 has been described, it will be readily apparent to those skilled in the art that a wide variety of other possible play environments, play structures, entertainment centers and the like may be used to create an interactive play environment within which the invention may be carried out. For instance, a suitable play structure may be constructed substantially entirely of molded or contoured concrete, fiberglass or plastic, as desired. Alternatively, a suitable play structure may be constructed entirely or partially from conduits or pipes which also transport play media to and from various locations throughout the play structure. Alternatively, the play environment need not comprise a play structure at all, but may be simply a themed play area, or even a multi-purpose area such as a restaurant dining facility, family room, bedroom or the like. Magic Wand As indicated above, play participants 105 within the play structure 100 learn to use a “Magic wand” 200 and/or other tracking/actuation device. The wand 200 allows play participants to electronically and “magically” interact with their surrounding play environment simply by pointing or using their wands in a particular manner to achieve desired goals or produce desired effects within the play environment. Use of the wand 200 may be as simple as touching it to a particular surface or “magical” item within the play structure 100 or it may be as complex as shaking or twisting the wand a predetermined number of times in a particular manner and/or pointing it accurately at a certain target desired to be “magically” transformed or otherwise affected. As play participants play and interact within the play structure 100 they learn more about the “magical” powers possessed by the wand 200 and become more adept at using the wand to achieve desired goals or desired play effects. Optionally, play participants may collect points or earn additional magic levels or ranks for each play effect or task they successfully achieve. In this manner, play participants 105 may compete with one another to see who can score more points and/or achieve the highest magic level. FIG. 2 illustrates the basic construction of one preferred embodiment of a “magic” wand 200 having features and advantages in accordance with one preferred embodiment of the invention. As illustrated in FIG. 2A the wand 200 basically comprises an elongated hollow pipe or tube 310 having a proximal end or handle portion 315 and a distal end or transmitting portion 320. If desired, an internal cavity may be provided to receive one or more batteries to power optional lighting, laser or sound effects and/or to power longer-range transmissions such as via an infrared LED transmitter device or RF transmitter device. An optional button 325 may also be provided, if desired, to enable particular desired functions, such as sound or lighting effects or longer-range transmissions. FIG. 2B is a partially exploded detail view of the proximal end 315 of the magic wand toy 200 of FIG. 2A. As illustrated, the handle portion 315 is fitted with optional combination wheels having various symbols and/or images thereon. Preferably, certain wand functions may require that these wheels be rotated to produce a predetermined pattern of symbols such as three owls, or an owl, a broom and a moon symbol. Those skilled in the art will readily appreciate that the combination wheels may be configured to actuate electrical contacts and/or other circuitry within the wand 200 in order to provide the desired functionality. Alternatively, the combinations wheels may provide a simple security measure to prevent unauthorized users from actuating the wand. FIG. 2C is a partial cross-section detail view of the distal end of magic wand toy 200 of FIG. 2A. As illustrated, the distal end 320 is fitted with an RFID (radio frequency identification device) transponder 335 that is operable to provide relatively short-range RF communications (<60 cm) with one or more of the receivers or transceivers 300 distributed throughout play structure 100 (FIG. 1). At its most basic level, RFID provides a wireless link to uniquely identify objects or people. It is sometimes called dedicated short range communication (DSRC). RFID systems include electronic devices called transponders or tags, and reader electronics to communicate with the tags. These systems communicate via radio signals that carry data either uni-directionally (read only) or, more preferably, bi-directionally (read/write). One suitable RFID transponder is the 134.2 kHz/123.2 kHz, 23 mm Glass Transponder available from Texas Instruments, Inc. (http://www.tiris.com, Product No. RI-TRP-WRHP). This transponder basically comprises a passive (non-battery-operated) RF transmitter/receiver chip 340 and an antenna 345 provided within an hermetically sealed vial 350. A protective silicon sheathing 355 is preferably inserted around the sealed vial 350 between the vial and the inner wall of the tube 310 to insulate the transponder from shock and vibration. FIG. 3 is a simplified schematic diagram of one embodiment of an RF transceiver 300 (FIG. 1) and optional master control system 375 for use with the magic wand toy actuator of FIG. 2A. As illustrated, the transceiver 300 basically comprises an RF Module 380, a Control Module 385 and an antenna 390. When the distal end of wand 200 comes within a predetermined range of antenna 390 (˜20-60 cm) the transponder antenna 345 (FIG. 2C) becomes excited and impresses a voltage upon the RF transmitter/receiver chip 340 disposed within transponder 335 at the distal end of the wand 200. In response, the RF transmitter/receiver chip 340 causes transponder antenna 345 to broadcast certain information stored within the transponder 335 comprising 80 bits of read/write memory. This information typically includes the users unique ID number, magic level or rank and/or certain other information pertinent to the user or the user's play experiences. This information is initially received by RF Module 380, which can then transfer the information through standard interfaces to an optional Host Computer 375, Control Module 385, printer, or programmable logic controller for storage or action. If appropriate, Control Module 385 provides certain outputs to activate or control one or more associated play effects, such as lighting, sound, various mechanical or pneumatic actuators or the like. Optional Host Computer 375 processes the information and/or communicates it to other transceivers 300, as may be required by the game. If suitably configured, RF Module 380 may also broadcast or “write” certain information back to the transponder 335 to change or update one of more of the 80 read/write bits in its memory. This exchange of communications occurs very rapidly (˜70 ms) and so from the user's perspective it appears to be instantaneous. Thus, the wand 200 may be used in this “short range” or “passive” mode to actuate various “magical” effects throughout the play structure 100 by simply touching or bringing the tip of the wand 200 into relatively close proximity with a particular transceiver 300. To provide added mystery and fun, certain transceivers 300 may be hidden within the play structure 100 so that they must be discovered by continually probing around the structure using the wand 200. The locations of the hidden transceivers may be changed from time to time to keep the game fresh and exciting. If desired, the wand 200 may also be configured for long range communications with one or more of the transceivers 300 (or other receivers) disposed within the play structure 100. For example, one or more transceivers 300 may be located on a roof or ceiling surface, on an inaccessible theming element, or other area out of reach of play participants. Such long-rage wand operation may be readily achieved using an auxiliary battery powered RF transponder, such as available from Axcess, Inc., Dallas, Tex. If line of sight or directional actuation is desired, a battery-operated infrared LED transmitter and receiver of the type employed in television remote control may be used, as those skilled in the art will readily appreciate. Of course, a wide variety of other wireless communications devices, as well as various sound and lighting effects may also be provided, as desired. Any one or more of these may be actuated via button 325, as desirable or convenient. Additional optional circuitry and/or position sensors may be added, if desired, to allow the “magic wand” 200 to be operated by waiving, shaking, stroking and/or tapping it in a particular manner. If provided, these operational aspects would need to be learned by play participants as they train in the various play environments. The ultimate goal, of course, is to become a “grand wizard” or master of the wand. This means that the play participant has learned and mastered every aspect of operating the wand to produce desired effects within each play environment. Of course, additional effects and operational nuances can (and preferably are) always added in order to keep the interactive experience fresh continually changing. Optionally, the wand 200 may be configured such that it is able to display 50 or more characters on a LTD or LCD screen. The wand may also be configured to respond to other signals, such as light, sound, or voice commands as will be readily apparent to those skilled in the art. RFID Tracking Card/Badge FIGS. 4A and 4B are front and rear views, respectively, of an optional or alternative RFID tracking badge or card 400 for use within the interactive play structure of FIG. 1. This may be used instead of or in addition to the wand 200, described above. The particular badge 400 illustrated is intended to be affixed or adhered to the front of a shirt or blouse worn by a play participant during their visit to suitably equipped play or entertainment facilities. The badge preferably comprises a paper, cardboard or plastic substrate having a front side 404 and a back side 410. The front 405 of each card/badge 400 may be imprinted with graphics, photos, or any other information desired. In the particular embodiment illustrated, the front 405 contains an image of Harry Potter in keeping with the overall theme of the play structure 100. In addition, the front 405 of the badge 400 may include any number of other designs or information pertinent to its application. For example, the guest's name 430, and group 435 may be indicated for convenient reference. A unique tag ID Number 440 may also be displayed for convenient reference and is particularly preferred where the badge 400 is to be reused by other play participants. The obverse side 410 of the badge 400 contains the badge electronics comprising a radio frequency tag 420 pre-programmed with a unique person identifier number (“UPIN”). The tag 420 generally comprises a spiral wound antenna 450, a radio frequency transmitter chip 460 and various electrical leads and terminals 470 connecting the chip 460 to the antenna. Advantageously, the UPIN may be used to identify and track individual play participants within the play facility. Optionally, each tag 420 may also include a unique group identifier number (“UGIN”) which may be used to match a defined group of individuals having a predetermined relationship—either pre-existing or contrived for purposes of game play. If desired, the tag 420 may be covered with an adhesive paper label (not shown) or, alternatively, may be molded directly into a plastic sheet substrate comprising the card 400. Various readers distributed throughout a park or entertainment facility are able to read the RFID tags 420. Thus, the UPIN and UGIN information can be conveniently read and provided to an associated master control system, display system or other tracking, recording or display device for purposes of creating a record of each play participant's experience within the play facility. This information may be used for purposes of calculating individual or team scores, tracking and/or locating lost children, verifying whether or not a child is inside a facility, photo capture & retrieval, and many other useful purposes as will be readily obvious and apparent to those skilled in the art. Preferably, the tag 420 is passive (requires no batteries) so that it is inexpensive to purchase and maintain. Such tags and various associated readers and other accessories are commercially available in a wide variety of configurations, sizes and read ranges. RFID tags having a read range of between about 10 cm to about 100 cm are particularly preferred, although shorter or longer read ranges may also be acceptable. The particular tag illustrated is the 13.56 mHz tag sold under the brand name Taggit™ available from Texas Instruments, Inc. (http://www.tiris.com, Product No. RI-103-110A). The tag 420 has a useful read/write range of about 25 cm and contains 256-bits of on-board memory arranged in 8×32-bit blocks which may be programmed (written) and read by a suitably configured read/write device. Such tag device is useful for storing and retrieving desired user-specific information such as UPIN, UGIN, first and/or last name, age, rank or level, total points accumulated, tasks completed, facilities visited, etc. If a longer read/write range and/or more memory is desired, optional battery-powered tags may be used instead, such as available from ACXESS, Inc. and/or various other vendors known to those skilled in the art. FIGS. 5 and 6 are simplified schematic illustrations of tag and reader operation. The tag 420 is initially activated by a radio frequency signal broadcast by an antenna 510 of an adjacent reader or activation device 500. The signal impresses a voltage upon the antenna 450 by inductive coupling which is then used to power the chip 460 (see, e.g., FIG. 5A). When activated, the chip 460 transmits via radio frequency a unique identification number preferably corresponding to the UPIN and/or UGIN described above (see, e.g., FIG. 5B). The signal may be transmitted either by inductive coupling or, more preferably, by propagation coupling over a distance “d” determined by the range of the tag/reader combination. This signal is then received and processed by the associated reader 500 as described above. If desired, the RFID card or badge 400 may also be configured for read/write communications with an associated reader/writer. Thus, the unique tag identifier number (UPIN or UGIN) can be changed or other information may be added. As indicated above, communication of data between a tag and a reader is by wireless communication. As a result, transmitting such data is always subject to the vagaries and influences of the media or channels through which the data has to pass, including the air interface. Noise, interference and distortion are the primary sources of data corruption that may arise. Thus, those skilled in the art will recognize that a certain degree of care should be taken in the placement and orientation of readers 500 so as to minimize the probability of such data transmission errors. Preferably, the readers are placed at least 30-60 cm away from any metal objects, power lines or other potential interference sources. Those skilled in the art will also recognize that the write range of the tag/reader combination is typically somewhat less (˜10-15% less) than the read range “d” and, thus, this should also be taken into account in determining optimal placement and positioning of each reader device 500. Typical RFID data communication is asynchronous or unsynchronized in nature and, thus, particular attention should be given in considering the form in which the data is to be communicated. Structuring the bit stream to accommodate these needs, such as via a channel encoding scheme, is preferred in order to provide reliable system performance. Various suitable channel encoding schemes, such as amplitude shift keying (ASK), frequency shift keying (FSK), phase shift keying (PSK) and spread spectrum modulation (SSM), are well know to those skilled in the art and will not be further discussed herein. The choice of carrier wave frequency is also important in determining data transfer rates. Generally speaking the higher the frequency the higher the data transfer or throughput rates that can be achieved. This is intimately linked to bandwidth or range available within the frequency spectrum for the communication process. Preferably, the channel bandwidth is selected to be at least twice the bit rate required for the particular game application. FIG. 7 is a simplified block diagram illustrating the basic organization and function of the electronic circuitry comprising the radio frequency transmitter chip 460 of the RFID tag device 420 of FIG. 4B. The chip 460 basically comprises a central processor 530, Analogue Circuitry 535, Digital Circuitry 540 and on-board memory 545. On-board memory 545 is divided into read-only memory (ROM) 550, random access memory (RAM) 555 and non-volatile programmable memory 560, which is available for data storage. The ROM-based memory 550 is used to accommodate security data and the tag operating system instructions which, in conjunction with the processor 530 and processing logic deals with the internal “house-keeping” functions such as response delay timing, data flow control and power supply switching. The RAM-based memory 555 is used to facilitate temporary data storage during transponder interrogation and response. The non-volatile programmable memory 560 may take various forms, electrically erasable programmable read only memory (EEPROM) being typical. It is used to store the transponder data and is preferably non-volatile to ensure that the data is retained when the device is in its quiescent or power-saving “sleep” state. Various data buffers or further memory components (not shown), may be provided to temporarily hold incoming data following demodulation and outgoing data for modulation and interface with the transponder antenna 450. Analog Circuitry 535 provides the facility to direct and accommodate the interrogation field energy for powering purposes in passive transponders and triggering of the transponder response. Analog Circuitry also provides the facility to accept the programming or “write” data modulated signal and to perform the necessary demodulation and data transfer processes. Digital Circuitry 540 provides certain control logic, security logic and internal microprocessor logic required to operate central processor 530. Role Play Character Cards The RFID card 400 illustrated and described above is used, in accordance with the afore-mentioned preferred embodiment, to identify and track individual play participants and/or groups of play participants within a play facility. However, in another preferred embodiment, the same card 400 and/or a similarly configured RFID or a magnetic “swipe” card or the like may be used to store certain powers or abilities of an imaginary role-play character that the card 400 represents. For example, card 400 may represent the Harry Potter character. As each play participant uses his or her favorite character card in various Harry Potter play facilities the Harry Potter character represented by the card 400 gains (or loses) certain attributes, such as magic skill level, magic strength, flight ability, various spell-casting abilities, etc. All of this information is preferably stored on the card 400 so that the character attributes may be easily and conveniently transported to other similarly-equipped play facilities, computer games, video games, home game consoles, hand-held game units, and the like. In this manner, an imaginary role-play character is created and stored on a card that is able to seamlessly transcend from one play medium to the next. For example, character attributes developed during a play a participant's visit to a local Harry Potter/Hogwart magic facility are stored on the card 400. When the play participant then revisits the same or another Harry Potter play facility, all of the attributes of his character are “remembered” on the card so that the play participant is able to continue playing with and developing the same role-play character. Similarly, various video games, home game consoles, and/or hand-held game units can be and preferably are configured to communicate with the card 400 in a similar manner as described above and/or using other well-known information storage and communication techniques. In this manner, a play participant can use the character card 400 and the role play character he or she has developed with specific associated attributes in a favorite video action game, role-play computer game or the like. FIGS. 8A-8D are front views of various alternative embodiments of possible role-play character cards for use within a Harry Potter/Hogwart interactive play structure such as illustrated in FIG. 1. Role play cards 600 are preferably constructed substantially the same as the card 400 illustrated and described above in connection with FIGS. 4B, 4B, except with different character illustrations and/or graphics. For example, each card 600 may include a different character from a Harry Potter storyline representing a role-play character desired to be imagined by a play participant. The obverse side (not shown) includes an RFID tag, such as illustrated and described above in connection with FIG. 4B. Alternatively, a magnetic “swipe” strip and/or other well-known information storage means may be used with efficacy, so long as it is relatively compact, durable and inexpensive. The particular size, shape and theme of the cards 600 is relatively unimportant. In the particular embodiment illustrated, the cards 600 are shaped and themed so as to be used as bookmarks for Harry Potter series books. These may be packaged and sold together with each Harry Potter book, or they may be sold separately as novelty items or the like. If desired, a hole or eyelet 610 may be provided at the top of each card 600 so as to facilitate wearing the card 600 as a pendant on a necklace 620 or as key-chain trinket. Smaller, pocket-sized cards and/or other similar RFID or magnetic transponder devices may also be used where convenience and market demand dictates. Such transponder devices are commercially available, such as from Texas Instruments, Inc. (http://www.tiris.com, e.g., Prod. Nos. RI-TRP-W9WK, RI-TRP-R9QL, RI-TRP-WFOB). Master Control System Depending upon the degree of game complexity desired and the amount of information sharing required, the transceivers 300 may or may not be connected to a master control system or central server 375 (FIG. 3). If a master system is utilized, preferably each wand 200 and/or RFID card 400, 600 is configured to electronically send and receive information to and from various receivers or transceivers 300 distributed throughout the play facility 100 using a send receive radio frequency (“SRRF”) communication protocol. This communications protocol provides the basic foundation for a complex, interactive entertainment system which creates a seemingly magic interactive play experience for play participants who possess and learn to use the magical wand. In its most refined embodiments, a user may electronically send and receive information to and from other wands and/or to and from a master control system located within and/or associated with any of a number of play environments, such as a family entertainment facility, restaurant play structure, television/video/radio programs, computer software program, game console, web site, etc. This newly created network of SRRF-compatible play and entertainment environments provides a complex, interactive play and entertainment system that creates a seamless magical interactive play experience that transcends conventional physical and temporal boundaries. SRRF may generally be described as an RF-based communications technology and protocol that allows pertinent information and messages to be sent and received to and from two or more SRRF compatible devices or systems. While the specific embodiments descried herein are specific to RF-based communication systems, those skilled in the art will readily appreciate that the broader interactive play concepts taught herein may be realized using any number of commercially available 2-way and/or 1-way medium range wireless communication devices and communication protocols such as, without limitation, infrared-, digital-, analog, AM/FM-, laser-, visual-, audio-, and/or ultrasonic-based systems, as desired or expedient. The SRRF system can preferably send and receive signals (up to 40 feet) between tokens and fixed transceivers. The system is preferably able to associate a token with a particular zone as defined by a token activation area approximately 10-15 feet in diameter. Different transceiver and antenna configurations can be utilized depending on the SRRF requirements for each play station. The SRRF facility tokens and transceivers are networked throughout the facility. These devices can be hidden in or integrated into the facility's infrastructure, such as walls, floors, ceilings and play station equipment. Therefore, the size and packaging of these transceivers is not particularly critical. In a preferred embodiment, an entire entertainment facility may be configured with SRRF technology to provide a master control system for an interactive entertainment play environment using SRRF-compatible magic wands and/or tracking devices. A typical entertainment facility provided with SRRF technology may allow 300-400 or more users to more-or-less simultaneously send and receive electronic transmissions to and from the master control system using a magic wand or other SRRF-compatible tracking device. In particular, the SRRF system uses a software program and data-base that can track the locations and activities of up to a hundred more users. This information is then used to adjust the play experience for the user based on “knowing” where the user/player has been, what objectives that player has accomplished and how many points or levels have been reached. The system can then send messages to the user throughout the play experience. For example, the system can allow or deny access to a user into a new play area based on how many points or levels reached by that user and/or based on what objectives that user has accomplished or helped accomplish. It can also indicate, via sending a message to the user the amount of points or specific play objectives necessary to complete a “mission” or enter the next level of play. The master control system can also send messages to the user from other users. The system is preferably sophisticated enough that it can allow multiple users to interact with each other adjusting the game instantly. The master system can also preferably interface with digital imaging and/or video capture so that the users activities can be visually tracked. Any user can locate another user either through the video capturing system or by sending a message to another device. At the end of a visit, users are informed of their activities and the system interfaces with printout capabilities. The SRRF system is preferably capable of sending and receiving signals up to 100 feet. Transmitter devices can also be hidden in walls or other structures in order to provide additional interactivity and excitement for play participants. Suitable embodiments of the SRRF technology described above may be obtained from a number of suitable sources, such as AXCESS, Inc. and, in particular, the AXCESS active RFID network system for asset and people tacking applications. In another preferred embodiment the system comprises a network of transceivers 300 installed at specific points throughout a facility. Players are outfitted or provided with a reusable “token”—a standard AXCESS personnel tag clipped to their clothing in the upper chest area. As each player enters a specific interactive play area or “game zone” within the facility, the player's token receives a low frequency activation signal containing a zone identification number (ZID). The token then responds to this signal by transmitting both its unique token identification number (TID) along with the ZID, thus identifying and associating the player with a particular zone. The token's transmitted signal is received by a transceiver 300 attached to a data network built into the facility. Using the data network, the transceiver forwards the TID/ZID data to a host computer system. The host system uses the SRRF information to log/track the guest's progress through the facility while interfacing with other interactive systems within the venue. For example, upon receipt of a TID/ZID message received from Zone 1, the host system may trigger a digital camera focused on that area, thus capturing a digital image of the player which can now be associated with both their TID and the ZID at a specific time. In this manner the SRRF technology allows the master control system to uniquely identify and track people as they interact with various games and activities in a semi-controlled play environment. Optionally, the system may be configured for two-way messaging to enable more complex interactive gaming concepts. In another embodiment, the SRRF technology can be used in the home. For enabling Magic at the home, a small SRRF module is preferably incorporated into one or more portable toys or objects that may be as small as a beeper. The SRRF module supports two-way communications with a small home transceiver, as well as with other SRRF objects. For example, a Magic wand 200 can communicate with another Magic wand 200. The toy or object may also include the ability to produce light, vibration or other sound effects based on signals received through the SRRF module. In a more advanced implementation, the magical object may be configured such that it is able to display preprogrammed messages of up to 50 characters on a LCD screen when triggered by user action (e.g. button) or via signals received through the SRRF module. This device is also preferably capable of displaying short text messages transmitted over the SRRF wireless link from another SRRF-compatible device. Preferably, the SRRF transceiver 300 is capable of supporting medium-to-long range (10-40 feet) two-way communications between SRRF objects and a host system, such as a PC running SRRF-compatible software. This transceiver 300 has an integral antenna and interfaces to the host computer through a dedicated communication port using industry standard RS232 serial communications. It is also desirable that the SRRF transmission method be flexible such that it can be embedded in television or radio signals, videotapes, DVDs, video games and other programs media, stripped out and re-transmitted using low cost components. The exact method for transposing these signals, as well as the explicit interface between the home transceiver and common consumer electronics (i.e. TVs, radios, VCRs, DVD players, A/V receivers, etc.) is not particularly important, so long as the basic functionality as described above is achieved. The various components needed to assemble such an SRRF system suitable for use with the present invention are commercially available and their assembly to achieve the desired functionality described above can be readily determined by persons of ordinary skill in the art. If desired, each SRRF transceiver may also incorporate a global positioning (“GPS”) device to track the exact location of each play participant within one or more play environments. Most desirably, a SRRF module can be provided in “chip” form to be incorporated with other electronics, or designed as a packaged module suitable for the consumer market. If desired, the antenna can be embedded in the module, or integrated into the toy and attached to the module. Different modules and antennas may be required depending on the function, intelligence and interfaces required for different devices. A consumer grade rechargeable or user replaceable battery may also be used to power both the SRRF module and associated toy electronics. Interactive Game Play The present invention may be carried out using a wide variety of suitable game play environments, storylines and characters, as will be readily apparent to those skilled in the art. The following specific game play examples are provided for purposes of illustration and for better understanding of the invention and should not be taken as limiting the invention in any way: EXAMPLE 1 An overall interactive gaming experience and entertainment system is provided (called the “Magic” experience), which tells a fantastic story that engages children and families in a never-ending adventure based on a mysterious treasure box filled with magical objects. Through a number of entertainment venues such as entertainment facilities, computer games, television, publications, web sites, and the like, children learn about and/or are trained to use these magical objects to become powerful “wizards” within one or more defined “Magic” play environments. The play environments may be physically represented, such as via an actual existing play structure or family entertainment center, and/or it may be visually/aurally represented via computer animation, television radio and/or other entertainment venue or source. The magical objects use the SRRF communications system allowing for messages and information to be received and sent to and from any other object or system. Optionally, these may be programmed and linked to the master SRRF system. Most preferably, the “magic wand” 200 is configured to receive messages from any computer software, game console, web site, and entertainment facility, television program that carries the SRRF system. In addition, the magic wand can also preferably send messages to any SRRF compatible system thus allowing for the “wand” to be tracked and used within each play environment where the wand is presented. The toy or wand 200 also preferably enables the user to interact with either a Master system located within a Magic entertainment facility and/or a home-based system using common consumer electronic devices such as a personal computer, VCR or video game system. The master control system for a Magic entertainment facility generally comprises: (1) a “Icken” (gag, toy, wand 200 or other device) carried by the user 105, (2) a plurality of receivers or transceivers 300 installed throughout the facility, (3) a standard LAN communications system (optional), and (4) a master computer system interfaced to the transceiver network (optional). If a Master computer system is used, preferably the software program running on the Master computer is capable of tracking the total experience for hundreds of users substantially in real time. The information is used to adjust the play for each user based on knowing the age of the user, where the user has played or is playing, points accumulated, levels reached and specific objectives accomplished. Based on real-time information obtained from the network, the system can also send messages to the user as they interact throughout the Magic experience. The Master system can quickly authorize user access to a new play station area or “zone” based on points or levels reached. It can also preferably indicate, via sending a message to the user, the points needed or play activities necessary to complete a “mission.” The Master system can also send messages to the user from other users. The system is preferably sophisticated enough to allow multiple users to interact with each other while enjoying the game in real-time. Optionally, the Master system can interface with digital imaging and video capture so that the users' activities can be visually tracked. Any user can then locate another user either through the video capturing system or by sending a message to another device. At the end of a visit, users are informed of their activities and other attributes related to the Magic experience via display or printout. For relatively simple interactive games, the Master system may be omitted in order to save costs. In that case, any game-related information required to be shared with other receivers or transceivers may be communicated via an RS-232 hub network, Ethernet, or wireless network, or such information may be stored on the want itself and/or an associated RFID card or badge carried by the play participant (discussed later). For retrofit applications, it is strongly preferred to provide substantially all stand-alone receivers or transceivers that do not communicate to a master system or network. This is to avoid the expense of re-wiring existing infrastructure. For these applications, any information required to be shared by the game system is preferably stored on the wand or other RFID device(s) carried by the play participants. Alternatively, if a more complex game experience is demanded, any number of commercially available wireless networks may be provided without requiring rewiring or existing infrastructure. EXAMPLE 2 A computer adventure game is provided in which one or more play participants assume the role of an imaginary character “Pajama Sam” from the popular series of computer games published by Humongous Entertainment, Inc. of Woodinville, W A. A Pajama Sam adventure character card 700, such as illustrated in FIGS. 9A, 9B, is provided to each play participant. The card may be packaged and sold together with the game software, and/or it may be sold separately, as convenience and market demands dictate. The card 700 may be constructed substantially the same as the cards 400, 600 illustrated and described above in connection with FIGS. 4 and 8, except with different character illustrations and/or graphics. For example, each card 700 may include a different character from the Pajama Sam computer game series representing a role-play character desired to be imagined by a play participant. The obverse side (FIG. 9B) includes an RFID tag 720, such as illustrated and described above in connection with FIG. 4B. Preferably, the tag 720 is covered with an adhesive paper label 725. Alternatively, the tag 720 may be molded directly into a plastic sheet substrate from which the card 700 is then formed. Alternatively, a magnetic “swipe” strip and/or other well-known information storage means may be used with efficacy, so long as it is relatively compact, durable and inexpensive. The particular size, shape and theme of the card 700 is relatively unimportant. In the particular embodiment illustrated, the card 700 is shaped and themed similar to a baseball trading card so that they may be collected and stored conveniently in any baseball card album or the like. If desired, a hole or eyelet (not shown) may be provided at the top of the card 700 so as to facilitate wearing the card 700 as a pendant on a necklace or as key-chain trinket. Of course, smaller, pocket-sized cards and/or other similar RFID or magnetic transponder devices may also be used where convenience and market demand dictates. Such alternative suitable transponder devices are commercially available, such as from Texas Instruments, Inc. (http://www.tiris.com, e.g., Prod. Nos. RI-TRP-W9WK, RI-TRP-R9QL, RI-TRP-WFOB). A specially configured computer, video game, home game console, hand-held gaming device or similar gaming device is provided with a reader, and more preferably a reader/writer such as described above, that is able to communicate with the tag 720 or other information storage means associated with the card 700. As each play participant plays his or her favorite Pajama Sam game the Pajama Sam character represented by the card 700 gains (or loses) certain attributes, such as speed, dexterity, and/or the possession of certain tools or objects associated with the game play. All of this information is preferably stored on the card 700 so that the character attributes may be easily and conveniently transported to other similarly-equipped computer games, video games, home game consoles, hand-held game units, play facilities, and the like. In this manner, an imaginary role-play character is created and stored on a card that is able to seamlessly transcend from one play medium to the next. For example, in the course of playing a typical Pajama Sam game, players must “find” certain objects or tools that they will use to solve certain puzzles or tasks presented by the game. Players “pick up” these objects or tools by clicking their mouse on the desired object. The computer game software then keeps a record of which objects have been collected and displays those objects on the computer screen when requested by the player. This is illustrated by FIG. 10A, which is a screen shot from the computer game, “Pajama Sam, in No Need to Hide When It's Dark Outside,” published by Humongous Entertainment., Inc. (D 1996. The game begins in Pajama Sam's bedroom, and the player is asked to find and click on certain objects 810 that Pajama Sam needs to begin his adventure—namely his flashlight, PajamaMan lunch box and PajamaMan mask. As these objects are located and collected, they are displayed on the bottom of the computer screen, as illustrated in FIG. 10A. FIG. 10B is a screen shot from the same game where the player faces his first challenge or puzzle to solve. He or she must somehow make Pajama Sam operate the elevator 815 to take Pajama Sam up into the tree house 820 where his archenemy “Darkness” resides. To solve the puzzle the player explores the scene with his mouse and clicks on objects that might be useful to solve the puzzle. Eventually, the player will discover a pile of rocks 825 which Pajama Sam picks up and tosses into the basket 830 to operate the elevator. In the next scene (FIG. 10C) Pajama Sam is inside the tree house and the player must decide which of three possible paths to take representing doors 840, 845 and 850. Doorway 850 leads to the scene illustrated in FIG. 10D in which Pajama Sam (and the player) is challenged to a trivia game by a pair of talking doors. The player chooses from different categories of questions and attempts to choose correct answers from a multiple choice list provided by the game (see FIG. 1E). Ultimately, the player is challenged with a question specific to the game (see FIG. 10F) and which requires the player to have visited a particular location within the game where the information is contained. If the player has not completed that portion of the computer game, he or she cannot answer the question posed and Pajama Sam cannot advance in the adventure game (see FIG. 10G). If the player were to quit the game at this point, he or she could save the game on the host computer and return to the same computer later to complete the adventure. But the Pajama Sam character itself, its attributes, experiences and accomplishments are not portable and cannot presently be transferred from one game or gaming environment to another. However, the Pajama Sam adventure card 700 in accordance with the present invention enables a play participant to continue the adventure somewhere else (e.g. at a friends house, or a video arcade facility) without having to restart the game and repeat the steps that the player has already accomplished. With the Pajama Sam adventure card 700, relevant details of the game experience and the Pajama Sam character are stored on the card 700 so that the player can take the card to another computer, game console, hand-held game device or a designated Pajama Sam play facility, to continue the adventure in a new and exciting play environment. For example, the Pajama Sam play facility could be configured as a physical play space similar to that described above in connection with FIG. 1, except having theming and game play that parallels that of one or more of the Pajama Same computer adventure games. Now our computer game player who has a Pajama Same adventure card 700 can visit this play facility and the facility would be able to read the information on the card and determine that this particular player has already completed the first puzzle in the first Pajama Sam computer adventure game. If the player desires, he or she will be allowed to advance automatically in the game play within the Pajama Sam play facility so that the player can work on a new puzzle. If the player successfully solves a new puzzle at the play facility, this information will be recorded on the Pajama Sam adventure card 700. The next time he or she plays the computer game the card can be automatically read and the computer experience can be modified or updated in accordance with the new information recorded on the card. In this manner, the character role-play experience becomes portable, personal and long-term. This, in turn, facilitates the development of even more sophisticated and complex role-play characters and longer, more enjoyable role play experiences as players are able to continue playing with and developing the same role-play character(s) over long periods of time and in different and varied play environments. Similarly, various other video games, home game consoles, and/or hand-held game units can be and preferably are configured to communicate with the Pajama Sam adventure card 700 in a similar manner as described above and/or using other well-known information storage and communication techniques. In this manner, a play participant can use the Pajama Sam adventure card 700 and the role play character he or she has developed with specific associated attributes in a favorite video action game, role-play computer game, internet adventure game or the like. EXAMPLE 3 A trading card game is provided wherein a plurality of cards depicting various real or imaginary persons, characters and/or objects are provided and wherein each card has recorded or stored thereon in an electronically readable format certain selected information pertaining to the particular person, character or object, such as performance statistics, traits/powers, or special abilities. The information is preferably stored on an RFID tracking tag associated with each card and which can be read electronically and wirelessly over a predetermined range preferably greater than about 1 cm when placed in the proximity of a suitably configured RF reader. Optionally, the RFID tag may be read/write capable such that it the information stored thereon may be changed or updated in any manner desired. Alternatively, a magnetic strip, bar code or similar information storage means may be used to store relevant information on the card. FIGS. 11A and 11B depict one preferred embodiment of a trading card 900 having features and advantages in accordance with the present invention. The particular trading card illustrated in FIG. 11A is provided in the theme of the popular Pokeman characters and, in particular, the character Pikachu. FIGS. 11C and 11D illustrate several other possible Pokeman themed trading cards which may be provided in accordance with the present invention. Each card preferably comprises a paper, cardboard or plastic substrate having a front side 905 and a back side 910. The front 905 of the card 900 may be imprinted with graphics, photos, or any other information as desired. In the particular embodiment illustrated, the front 905 contains an image of the Pikachu character 925 in keeping with the Pokeman theme. In addition, the front 905 of the card 900 may include any number of other designs or information 930 pertinent to its application. For example, the character's type, size and evolution may be indicated, along with any special powers or traits the character may possess. The obverse side 910 of the card 900 preferably contains the card electronics comprising a radio frequency tag 920 pre-programmed with the pertinent information for the particular person, character or object portrayed on the front of the card. The tag 920 generally comprises a spiral wound antenna 950, a radio frequency transmitter chip 960 and various electrical leads and terminals 970 connecting the chip 960 to the antenna. If desired, the tag 920 may be covered with an adhesive paper label (not shown) or, alternatively, the tag may be molded directly into a plastic sheet substrate from which the card 900 is formed. Preferably, the tag 920 is passive (requires no batteries) so that it is inexpensive to purchase and maintain. Such tags and various associated readers and other accessories are commercially available in a wide variety of configurations, sizes and read ranges. RFID tags having a read range of between about 10 cm to about 100 cm are particularly preferred, although shorter or longer read ranges may also be acceptable. The particular tag illustrated is the 13.56 mHz tag sold under the brand name Taggit™ available from Texas Instruments, Inc. (http://www.tiris.com, Product No. RI-103-110A). The tag 920 has a useful read/write range of about 25 cm and contains 256-bits of on-board memory arranged in 8×32-bit blocks which may be programmed (written) and read by a suitably configured read/write device. If a longer read/write range and/or more memory is desired, optional battery-powered tags may be used instead, such as available from ACXESS, Inc. and/or various other vendors known to those skilled in the art. Cards 900 may be collected or traded and/or they may be used to play various games, such as a Pokeman arena competition using an electronic interface capable of reading the card information. Such games may be carried out using a specially configured gaming device or, alternatively, using a conventional computer gaming platform, home game console, arcade game console, hand-held game device, internet gaming device or other gaming device that has been modified to include an RF reader or magnetic “swipe” reader device as illustrated and described above. Advantageously, play participants can use the trading cards 900 to transport a information pertinent to a particular depicted person, character or object to a favorite computer action game, adventure game, interactive play structure or the like. For example, a suitably configured video game console and video game may be provided which reads the card information and recreates the appearance and/or traits of particular depicted person, character of object within the game. If desired, the game console may further be configured to write information to the card in order to change or update certain characteristics or traits of the character, person or object depicted by the card 900 in accordance with a predetermined game play progression. Of course, those skilled in the art will readily appreciate that the underlying concept of an RIFD trading card 900 and card game is not limited to cards depicting fantasy characters or objects, but may be implemented in a wide variety of alternative embodiments, including sporting cards, baseball, football and hockey cards, movie character cards, dinosaur cards, educational cards and the like. If desired, any number of other suitable collectible/tradable tokens or trinkets may also be provided with a similar RFID tag device in accordance with the teachings of the present invention as dictated by consumer tastes and market demand. Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to children's' play toys and games and, in particular, to interactive toys, games and play systems utilizing radio frequency transponders and transceivers to provide a unique interactive game play experience. 2. Description of the Related Art Family entertainment centers, play structures and other similar facilities are well known for providing play and interaction among play participants playing in, or around an entertainment facility and/or play structure. See, for example, U.S. Pat. No. 5,853,332 to Briggs, incorporated herein by reference. A wide variety of commercially available play toys and games are also known for providing valuable learning and entertainment opportunities for children, such as role playing, reading, memory stimulation, tactile coordination and the like. However, there is always a demand for more exciting and entertaining games and toys that increase the learning and entertainment opportunities for children and stimulate creativity and imagination. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a unique method of game play carried out within either an existing or specially configured entertainment facility or play structure. The game utilizes an interactive “wand” and/or other tracking/actuation device to allow play participants to electronically and “magically” interact with their surrounding play environment(s). The play environment may either be real or imaginary (i.e. computer/TV generated), and either local or remote, as desired. Optionally, multiple play participants, each provided with a suitable “wand” and/or tracking device, may play and interact together, either within or outside the play environment, to achieve desired goals or produce desired effects within the play environment. In accordance with one embodiment the present invention provides an interactive play system and seemingly magical wand toy for enabling a trained user to electronically send and receive information to and from other wand toys and/or to and from various transceivers distributed throughout a play facility and/or connected to a master control system. The toy wand or other seemingly magical object is configured to use a send/receive radio frequency communication protocol which provides a basic foundation for a complex, interactive entertainment system to create a seemingly magic interactive play experience for play participants who possess and learn to use the magical wand toy. In accordance with another embodiment the present invention provides an interactive play structure in the theme of a “magic” training center for would-be wizards in accordance with the popular characters and storylines of the children's' book series “Harry Potter” by J. K Rowling. Within the play structure, play participants learn to use a “magic wand” and/or other tracking/actuation device. The wand allows play participants to electronically and “magically” interact with their surrounding play environment simply by pointing or using their wands in a particular manner to achieve desired goals or produce desired effects within the play environment. Various receivers or transceivers are distributed throughout the play structure to facilitate such interaction via wireless communications. In accordance with another embodiment the present invention provides a wand actuator device for actuating various interactive play effects within an RFID-compatible play environment. The wand comprises an elongated hollow pipe or tube having a proximal end or handle portion and a distal end or transmitting portion. An internal cavity may be provided to receive one or more batteries to power optional lighting, laser or sound effects and/or to power long-range transmissions such as via an infrared LED transmitter device or RF transmitter device. The distal end of the wand is fitted with an RFID (radio frequency identification device) transponder that is operable to provide relatively short-range RF communications (<60 cm) with one or more receivers or transceivers distributed throughout a play environment. The handle portion of the wand is fitted with optional combination wheels having various symbols and/or images thereon which may be rotated to produce a desired pattern of symbols required to operate the wand or achieve one or more special effects. In accordance with another embodiment the present invention provides an RFID card or badge intended to be affixed or adhered to the front of a shirt or blouse worn by a play participant while visiting an RF equipped play facility. The badge comprises a paper, cardboard or plastic substrate having a front side and a back side. The front side may be imprinted with graphics, photos, or any other information desired. The front side may include any number of other designs or information pertinent to its application. The obverse side of the badge contains certain electronics comprising a radio frequency tag pre-programmed with a unique person identifier number (“UPIN”). The UPIN may be used to identify and track individual play participants within the play facility. Optionally, each tag may also include a unique group identifier number (“UGIN”) which may be used to match a defined group of individuals having a predetermined relationship. In accordance with another embodiment the present invention provides an electronic role-play game utilizing specially configured electronically readable character cards. Each card is configured with an RFID or a magnetic “swipe” strip or the like, that may be used to store certain information describing the powers or abilities of an imaginary role-play character that the card represents. As each play participant uses his or her favorite character card in various play facilities the character represented by the card gains (or loses) certain attributes, such as magic skill level, magic strength, flight ability, various spell-casting abilities, etc. All of this information is preferably stored on the card so that the character attributes may be easily and conveniently transported to other similarly-equipped play facilities, computer games, video games, home game consoles, hand-held game units, and the like. In this manner, an imaginary role-play character is created and stored on a card that is able to seamlessly transcend from one play medium to the next. In accordance with another embodiment the present invention provides a trading card game wherein a plurality of cards depicting various real or imaginary persons, characters and/or objects are provided and wherein each card has recorded or stored thereon in an electronically readable format certain selected information pertaining to the particular person, character or object, such as performance statistics, traits/powers, or special abilities. The information is preferably stored on an RFID tracking tag associated with each card and which can be read electronically and wirelessly over a predetermined range preferably greater than about 1 cm when placed in the proximity of a suitably configured RF reader. Optionally, the RFID tag may be read/write capable such that it the information stored thereon may be changed or updated in any manner desired. Alternatively, a magnetic strip, bar code or similar information storage means may be used to store relevant information on the card. For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed. | 20040713 | 20101214 | 20060209 | 77180.0 | A63F924 | 1 | DEODHAR, OMKAR A | MAGIC-THEMED ADVENTURE GAME | UNDISCOUNTED | 1 | CONT-ACCEPTED | A63F | 2,004 |
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10,889,975 | ACCEPTED | Broadband cable network utilizing common bit-loading | A broadband cable network (“BCN”) for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in the BCN is disclosed. The BCN may include a transmitting node within the plurality of nodes where the transmitting node is capable of sending a probe signal to the plurality of nodes, and at least one receiving node within the plurality of nodes in signal communication with the transmitting node. The at least one receiving node is capable of transmitting a first response signal in response to receiving the probe signal. The first response signal includes a first bit-loading modulation scheme determined by the at least one receiving node. The transmitting node is further capable of determining the common bit-loading modulation scheme from the first response signal. | 1. A method for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in a broadband cable network (“BCN”), the method comprising: transmitting a probe signal from a transmitting node within the plurality of nodes to a sub-plurality of receiving nodes within the plurality of nodes; receiving a plurality of response signals from the sub-plurality of receiving nodes wherein each response signal includes a bit-loading modulation scheme determined by a corresponding receiving node; and determining the common bit-loading modulation scheme from the received plurality of response signals. 2. The method of claim 1, further including transmitting a broadcast signal from the transmitting node to the plurality of receiving nodes, wherein the broadcast signal utilizes the common bit-loaded modulation scheme. 3. The method of claim 1, wherein the probe signal utilizes a bit-loaded modulation scheme that is capable of being received by all the receiving nodes within the sub-plurality of receiving nodes. 4. The method of claim 1, further including: receiving the probe signal at one receiving node of the plurality of receiving nodes through a channel path of transmission; determining the transmission characteristics of the channel path at the one receiving node; and transmitting a response signal from the one receiving node to the transmitting node. 5. The method of claim 4, wherein the transmission characteristics of the channel path are determined by measuring the signal-to-noise (“SNR”) characteristics of the received probe signal at the one receiving node. 6. The method of claim 5, further including generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 7. The method of claim 6, wherein determining a common bit-loading modulation scheme includes: comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 8. The method of claim 4, wherein the transmission characteristics of the channel path are determined by measuring the bit-error rate (“BER”) characteristics of the received probe signal at the one receiving node. 9. The method of claim 8, further including generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 10. The method of claim 9, wherein determining a common bit-loading modulation scheme includes: comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 11. The method of claim 4, wherein the transmission characteristics of the channel path are determined by measuring the product-error rate (“PER”) characteristics of the received probe signal at the one receiving node. 12. The method of claim 11, further including generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 13. The method of claim 12, wherein determining a common bit-loading modulation scheme includes; comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 14. The method of claim 1, wherein each bit-loading modulation scheme utilizes a quadrature phase shift keying (“QPSK”) modulation scheme. 15. The method of claim 1, wherein the each bit-loading modulation scheme utilizes quadrature amplitude modulation (“QAM”). 16. The method of claim 15, wherein each bit-loading modulation scheme is chosen from the group essentially consisting of 64 QAM modulation, 128 QAM modulation, 256 QAM modulation, 512 QAM modulation and 1024 QAM modulation. 17. A computer-readable medium having software for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in a broadband cable network (“BCN”), the computer-readable medium comprising: logic configured for transmitting a probe signal from a transmitting node within the plurality of nodes to a sub-plurality of receiving nodes within the plurality of nodes; logic configured for receiving a plurality of response signals from the sub-plurality of receiving nodes wherein each response signal includes a bit-loading modulation scheme determined by a corresponding receiving node; and logic configured for determining the common bit-loading modulation scheme from the received plurality of response signals. 18. The computer-readable medium of claim 17, further including logic configured for transmitting a broadcast signal from the transmitting node to the plurality of receiving nodes, wherein the broadcast signal utilizes the common bit-loaded modulation scheme. 19. The computer-readable medium of claim 17, wherein the probe signal utilizes a bit-loaded modulation scheme that is capable of being received by all the receiving nodes within the sub-plurality of receiving nodes. 20. The computer-readable medium of claim 17, further including: logic configured for receiving the probe signal at one receiving node of the plurality of receiving nodes through a channel path of transmission; logic configured for determining the transmission characteristics of the channel path at the one receiving node; and logic configured for transmitting a response signal from the one receiving node to the transmitting node. 21. The computer-readable medium of claim 20, wherein the transmission characteristics of the channel path are determined by logic configured for measuring the signal-to-noise (“SNR”) characteristics of the received probe signal at the one receiving node. 22. The computer-readable medium of claim 21, further including logic configured for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 23. The computer-readable medium of claim 22, wherein the logic configured for determining a common bit-loading modulation scheme includes: logic configured for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and logic configured for determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 24. The computer-readable medium of claim 17, wherein the transmission characteristics of the channel path are determined by logic configured for measuring the bit-error rate (“BER”) characteristics of the received probe signal at the one receiving node. 25. The computer-readable medium of claim 24, further including logic configured for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 26. The computer-readable medium of claim 25, wherein the logic configured determining a common bit-loading modulation scheme includes: logic configured for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and logic configured for determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 27. The computer-readable medium of claim 17, wherein the transmission characteristics of the channel path are determined by logic configured for measuring the product-error rate (“PER”) characteristics of the received probe signal at the one receiving node. 28. The computer-readable medium of claim 27, further including logic configured for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 29. The computer-readable medium of claim 28, wherein determining a common bit-loading modulation scheme includes: logic configured for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and logic configured for determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 30. A broadband cable network (“BCN”) for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in the BCN, the BCN comprising: a transmitting node within the plurality of nodes, the transmitting node capable of sending a probe signal; a sub-plurality of receiving nodes within the plurality of nodes wherein the sub-plurality of receiving nodes are capable of transmitting a sub-plurality of response signals in response to receiving the probe signal, wherein the sub-plurality of response signals includes a plurality of bit-loading modulation schemes, wherein each bit-loading modulation scheme of the plurality of bit-loading modulation schemes is determined by a receiving node within the sub-plurality of receiving nodes; and wherein the transmitting node is capable of determining the common bit-loading modulation scheme from the sub-plurality of response signals. 31. The BCN of claim 30, wherein the transmitting node is further capable of determining the common bit-loading modulation scheme in response to comparing all bit-loading modulation schemes within the plurality of bit-loading modulation schemes. 32. The BCN of claim 31, wherein each bit-loading modulation scheme utilizes a quadrature phase shift keying (“QPSK”) modulation. 33. The BCN of claim 31, wherein the each bit-loading modulation scheme utilizes quadrature amplitude modulation (“QAM”). 34. The BCN of claim 33, wherein each bit-loading modulation scheme is chosen from the group essentially consisting of 64 QAM modulation, 128 QAM modulation, 256 QAM modulation, 512 QAM modulation and 1024 QAM modulation. 35. The BCN of claim 30, wherein a receiving node within the sub-plurality of receiving nodes is capable of: receiving the probe signal at the receiving node through a channel path of transmission; determining the transmission characteristics of the channel path at the receiving node; and transmitting a response signal, of the sub-plurality of response signals, from the receiving node to the transmitting node. 36. The BCN of claim 35, wherein the receiving node is capable of determining the transmission characteristics of the channel path by measuring the signal-to-noise (“SNR”) characteristics of the received probe signal at the receiving node. 37. The BCN of claim 36, wherein the receiving node is capable of generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the receiving node in response to determining the transmission characteristics of the channel path. 38. The BCN of claim 37, wherein the transmitting node is capable of determining a common bit-loading modulation scheme by: comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 39. The BCN of claim 35, wherein the receiving node is capable of determining the transmission characteristics of the channel path by measuring the bit-error rate (“BER”) characteristics of the received probe signal at the one receiving node. 40. The BCN of claim 39, wherein the receiving node is capable of generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the receiving node in response to determining the transmission characteristics of the channel path. 41. The BCN of claim 40, wherein the transmitting node is capable of determining a common bit-loading modulation scheme by: comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 42. The BCN of claim 35, wherein the receiving node is capable of determining the transmission characteristics of the channel path by measuring the product-error rate (“PER”) characteristics of the received probe signal at the one receiving node. 43. The BCN of claim 42, wherein the receiving node is capable of generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the receiving node in response to determining the transmission characteristics of the channel path. 44. The BCN of claim 43, wherein the transmitting node is capable of determining a common bit-loading modulation scheme by; comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 45. The BCN of claim 30, wherein the transmitting node and the receiving nodes are the same type of devices. 46. A broadband cable network (“BCN”) for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in the BCN, the BCN comprising: a transmitting node within the plurality of nodes, the transmitting node having means for sending a probe signal; and a sub-plurality of receiving nodes within the plurality of nodes, wherein the sub-plurality of receiving nodes have means for transmitting a sub-plurality of response signals in response to receiving the probe signal, wherein the sub-plurality of response signals includes a plurality of bit-loading modulation schemes, wherein each bit-loading modulation scheme of the plurality of bit-loading modulation schemes is determined by a receiving node within the sub-plurality of receiving nodes; and wherein the transmitting node includes means for determining the common bit-loading modulation scheme from the sub-plurality of response signals. 47. The BCN of claim 46, wherein the transmitting node further includes means for determining the common bit-loading modulation scheme in response to comparing all bit-loading modulation schemes within the plurality of bit-loading modulation schemes. 48. The BCN of claim 46, wherein the transmitting node further includes means for determining the common bit-loading modulation scheme in response to comparing all bit-loading modulation schemes within the plurality of bit-loading modulation schemes. 49. The BCN of claim 48, wherein each bit-loading modulation scheme utilizes a quadrature phase shift keying (“QPSK”) modulation. 50. The BCN of claim 48, wherein the each bit-loading modulation scheme utilizes quadrature amplitude modulation (“QAM”). 51. The BCN of claim 50, wherein each bit-loading modulation scheme is chosen from the group essentially consisting of 64 QAM modulation, 128 QAM modulation, 256 QAM modulation, 512 QAM modulation and 1024 QAM modulation. 52. The BCN of claim 46, wherein a receiving node within the sub-plurality of receiving nodes includes: means for receiving the probe signal at the receiving node through a channel path of transmission; means for determining the transmission characteristics of the channel path at the receiving node; and means for transmitting a response signal, of the sub-plurality of response signals, from the receiving node to the transmitting node. 53. The BCN of claim 52, wherein the receiving node includes means for determining the transmission characteristics of the channel path by measuring the signal-to-noise (“SNR”) characteristics of the received probe signal at the receiving node. 54. The BCN of claim 53, wherein the receiving node includes means for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the receiving node in response to determining the transmission characteristics of the channel path. 55. The BCN of claim 54, wherein the transmitting node includes means for determining a common bit-loading modulation scheme. 56. The BCN of claim 55, wherein the means for determining a common bit-loading modulation scheme includes: means for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and means for determining the common bit-loading modulation scheme in response to the means for comparing the plurality of bit-loaded modulation schemes. 57. The BCN of claim 51, wherein the receiving node includes means for determining the transmission characteristics of the channel path by measuring the bit-error rate (“BER”) characteristics of the received probe signal at the one receiving node. 58. The BCN of claim 57, wherein the receiving node includes means for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the receiving node in response to determining the transmission characteristics of the channel path. 59. The BCN of claim 58, wherein the transmitting node includes means for determining a common bit-loading modulation scheme. 60. The BCN of claim 59, wherein the means for determining a common bit-loading modulation scheme includes: means for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and means for determining the common bit-loading modulation scheme in response to the means for comparing the plurality of bit-loaded modulation schemes. 61. The BCN of claim 51, wherein the receiving node includes means for determining the transmission characteristics of the channel path by measuring the product-error rate (“PER”) characteristics of the received probe signal at the one receiving node. 62. The BCN of claim 61, wherein the receiving node includes means for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the receiving node in response to determining the transmission characteristics of the channel path. 63. The BCN of claim 62, wherein the transmitting node includes means for determining a common bit-loading modulation scheme. 64. The BCN of claim 63, wherein the means for determining a common bit-loading modulation scheme includes: means for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and means for determining the common bit-loading modulation scheme in response to the means for comparing the plurality of bit-loaded modulation schemes. 65. The BCN of claim 46, wherein the transmitting node and the receiving nodes are the same type of devices. 66. A broadband cable network (“BCN”) for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in the BCN, the BCN comprising: means for transmitting a probe signal from a transmitting node within the plurality of nodes to a sub-plurality of receiving nodes within the plurality of nodes; means for receiving a plurality of response signals from the sub-plurality of receiving nodes wherein each response signal includes a bit-loading modulation scheme determined by a corresponding receiving node; and means for determining the common bit-loading modulation scheme from the received plurality of response signals. 67. The BCN of claim 66, further including means for transmitting a broadcast signal from the transmitting node to the plurality of receiving nodes, wherein the broadcast signal utilizes the common bit-loaded modulation scheme. 68. The BCN of claim 66, wherein the probe signal utilizes a bit-loaded modulation scheme that is capable of being received by all the receiving nodes within the sub-plurality of receiving nodes. 69. The BCN of claim 66, further including: means for receiving the probe signal at one receiving node of the plurality of receiving nodes through a channel path of transmission; means for determining the transmission characteristics of the channel path at the one receiving node; and means for transmitting a response signal from the one receiving node to the transmitting node. 70. The BCN of claim 69, wherein the one receiving node includes means for determining the transmission characteristics of the channel path by measuring the signal-to-noise (“SNR”) characteristics of the received probe signal at the one receiving node. 71. The BCN of claim 70, further including means for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 72. The BCN of claim 71, wherein the means for determining a common bit-loading modulation scheme includes: means for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and means for determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 73. The BCN of claim 69, wherein the one receiving node includes means for determining the transmission characteristics of the channel path by measuring the bit-error rate (“BER”) characteristics of the received probe signal at the one receiving node. 74. The BCN of claim 73, further including means for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 75. The BCN of claim 74, wherein the means for determining a common bit-loading modulation scheme includes: means for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and means for determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 76. The BCN of claim 69, wherein the one receiving node includes means for determining the transmission characteristics of the channel path by measuring the product-error rate (“PER”) characteristics of the received probe signal at the one receiving node. 77. The BCN of claim 75, further including means for generating the response signal, wherein the response signal utilizes a bit-loading modulation scheme that is generated by the one receiving node in response to determining the transmission characteristics of the channel path. 78. The BCN of claim 77, wherein the means for determining a common bit-loading modulation scheme includes: means for comparing a plurality of bit-loading modulation schemes from the corresponding received plurality of response signals; and means for determining the common bit-loading modulation scheme in response to comparing the plurality of bit-loaded modulation schemes. 79. The BCN of claim 66, wherein each bit-loading modulation scheme utilizes a quadrature phase shift keying (“QPSK”) modulation scheme. 80. The BCN of claim 66, wherein the each bit-loading modulation scheme utilizes quadrature amplitude modulation (“QAM”) scheme. 81. The BCN of claim 80, wherein each bit-loading modulation scheme is chosen from the group essentially consisting of 64 QAM modulation, 128 QAM modulation, 256 QAM modulation, 512 QAM modulation and 1024 QAM modulation. | REFERENCE TO EARLIER-FILED APPLICATIONS This application is a continuation-in-part of U.S. Utility application Ser. No. 10/788,505 titled “Network Interface Device and Broadband Local Area Network Using Coaxial Cable,” filed Feb. 13, 2004, which is a continuation of U.S. Utility application Ser. No. 09/910,412 titled “Network Interface Device and Broadband Local Area Network Using Coaxial Cable,” filed Jul. 21, 2001, which claims the benefit of U.S. Provisional Application Ser. No. 60/288,967 titled “Network Interface and Broadband Local Area Network Using Coaxial Cable,” filed May 4, 2001, all of which applications are incorporated herein, in their entirety, by this reference. This application is also a continuation-in-part of U.S. Utility application Ser. No. 10/322,834 titled “Broadband Network for Coaxial Cable Using Multi-carrier Modulation,” filed Dec. 18, 2002, which is a continuation of U.S. Utility application Ser. No. 10/230,687 titled “Broadband Network for Coaxial Cable Using Multi-carrier Modulation,” filed Aug. 29, 2002, now abandoned, which claims the benefit of the following U.S. Provisional Applications: (a) Ser. No. 60/316,820 titled “Broadband Local Area Network Using Coaxial Cable,” filed Aug. 30, 2001; (b) Ser. No. 60/363,420 titled “Method of Bit and Energy Loading to Reduce Interference Effects in Devices Sharing a Communication Medium,” filed Mar. 12, 2002; and (c) Ser. No. 60/385,361 titled “Power Loading to Reduce Interference Effects in Devices Sharing a Communication Medium,” filed Jun. 3, 2002, all of which applications are incorporated herein, in their entirety, by this reference. BACKGROUND OF THE INVENTION 1. Field of Invention The invention relates to broadband communication networks, and in particular to broadband communication networks utilizing coaxial cable. 2. Related Art The worldwide utilization of external television (“TV”) antennas for receiving broadcast TV, and of cable television and satellite TV is growing at a rapid pace. These TV signals from an external TV antenna, cable TV and satellite TV (such as from direct broadcast satellite “DBS” system) are usually received externally to a building (such as a home or an office) at a point-of-entry (“POE”). There may be multiple TV receivers and/or video monitors within the building and these multiple TV receivers may be in signal communication with the POE via a broadband cable network that may include a plurality of broadband cables and broadband cable splitters. Generally, these broadband cable splitters distribute downstream signals from the POE to various terminals (also known as “nodes”) in the building. The nodes may be connected to various types of customer premise equipment (“CPE”) such as cable converter boxes, televisions, video monitors, cable modems, cable phones and video game consoles. Typically, these broadband cables and broadband cable splitters are implemented utilizing coaxial cables and coaxial cable splitters, respectively. Additionally, in the case of cable TV or satellite TV, the multiple TV receivers may be in signal communication with the broadband cable network via a plurality of cable converter boxes, also known as set-top boxes (“STBs”), that are connected between the multiple TV receivers and the broadband cable network via a plurality of network nodes. Typically, a STB connects to a coaxial cable from a network node (such as the wall outlet terminal) to receive cable TV and/or satellite TV signals. Usually, the STB receives the cable TV and/or satellite TV signals from the network node and converts them into tuned TV signals that may be received by the TV receiver and/or video signals that may be received by a video monitor. In FIG. 1, an example known broadband cable network 100 (also known as a “cable system” and/or “cable wiring”) is shown within a building 102 (also known as customer premises or “CP”) such as a typical home or office. The broadband cable system 100 may be in signal communication with an optional cable service provider 104, optional broadcast TV station 106, and/or optional DBS satellite 108, via signal path 110, signal path 112 and external antenna 114, and signal path 116 and DBS antenna 118, respectively. The broadband cable system 100 also may be in signal communication with optional CPEs 120, 122 and 124, via signal paths 126, 128 and 130, respectively. In FIG. 2, another example known broadband cable system is shown within a building (not shown) such as a typically home. The cable system 200 may be in signal communication with a cable provider (not shown), satellite TV dish (not shown), and/or external antenna (not shown) via a signal path 202 such as a main coaxial cable from the building to a cable connection switch (not shown) outside of the building. The cable system 200 may include a POE 204 and main splitter 206, a sub-splitter 208, and STBs A 210, B 212 and C 214. Within the cable system 200, the POE 204 may be in signal communication with main splitter 206 via signal path 216. The POE 204 may be the connection point from the cable provider which is located external to the building of the cable system 200. The POE 202 may be implemented as a coaxial cable connector, transformer and/or filter. The main splitter 206 may be in signal communication with sub-splitter 208 and STB A 210 via signal paths 218 and 220, respectively. The sub-splitter 208 may be in signal communication with STB B 212 and STB C 214 via signal paths 222 and 224, respectively. The main splitter 206 and sub-splitter 208 may be implemented as coaxial cable splitters. The STB A 210, B 212 and C 214 may be implemented by numerous well known STB coaxial units such as cable television set-top boxes and/or satellite television set-top boxes. Typically, the signal paths 202, 216, 218, 220, 222 and 224 may be implemented utilizing coaxial cables. In an example operation, the cable system 200 would receive CATV, cable and/or satellite radio frequency (“RF”) TV signals 226 via signal path 202 at the POE 204. The POE 204 may pass, transform and/or filter the received RF signals to a second RF signal 228 that may be passed to the main splitter 206 via signal path 216. The main splitter 206 may then split the second RF signal 228 into split RF signals 230 and 232. The split RF signal 230 is then passed to the sub-splitter 208 and the split RF signal 232 is passed to the STB A 210 via signal paths 218 and 220, respectively. Once the split RF signal 232 is received by the STB A 210, the STB A 210 may convert the received split RF signal 232 into a baseband signal 238 that may be passed to a video monitor (not shown) in signal communication with the STB A 210. Once the split RF signal 230 is received by the sub-splitter 208, the sub-splitter 208 splits the received split RF signal 230 into sub-split RF signals 234 and 236 that are passed to STB B 212 and STB C 214 via signal paths 222 and 224, respectively. Once the sub-split RF signals 234 and 236 are received by the STB B 212 and STB C 214, respectively, the STB B 212 and STB C 214 may convert the received sub-split RF signals 234 and 236 into baseband signals 240 and 242, respectively, that may be passed to video monitors (not shown) in signal communication with STB B 212 and STB C 214. As the utilization of the numbers and types of CPEs in buildings increase (such as the number of televisions, video monitors, cable modems, cable phones, video game consoles, etc., increase in a typical home or office environment), there is a growing need for different CPEs to communicate between themselves in a network type of environment within the building. As an example, users in a home may desire to play network video games between different rooms in home environment utilizing the coaxial cable network installed throughout the home. Additionally, in another example, users in a home may want to share other types of digital data (such video and/or computer information) between different rooms in a home. Unfortunately, most broadband cable networks (such as the examples shown in both FIG. 1 and FIG. 2) presently utilized within most existing buildings are not configured to allow for easy networking between CPEs because most broadband cable networks utilize broadband cable splitters that are designed to split an incoming signal from the POE into numerous split signals that are passed to the different nodes in different rooms. As an example, in a typical home the signal splitters are commonly coaxial cable splitters that have an input port and multiple output ports. Generally, the input port is known as a common port and the output ports are known as tap ports. These types of splitters are generally passive devices and may be constructed using lumped element circuits with discrete transformers, inductors, capacitors, and resistors and/or using strip-line or microstrip circuits. These types of splitters are generally bi-directional because they may also function as signal combiners, which sum the power from the multiple tap ports into a single output at the common port. However, presently many CPEs utilized in modern cable and DBS systems have the ability to transmit as well as receive. If a CPE is capable of transmitting an upstream signal, the transmitted upstream signal from that CPE typically flows through the signal splitters back to the POE and to the cable and/or DBS provider. In this reverse flow direction, the signal splitters function as signal combiners for upstream signals from the CPEs to the POE. Usually, most of the energy from the upstream signals is passed from the CPEs to the POE because the splitters typically have a high level of isolation between the different connected terminals resulting in significant isolation between the various CPEs. The isolation creates a difficult environment to network between the different CPEs because the isolation results in difficulty for transmitting two-way communication data between the different CPEs. Unfortunately, CPEs are becoming increasingly complex and a growing number of users desire to connect these multiple CPEs into different types of networks. Therefore, there is a need for a system and method to connect a variety of CPEs into a local network, such as local-area network (“LAN”), within a building such as a home or office. Additionally, there is a need for a system and method to connect a variety of CPEs into a local network, such as a LAN, within a building such as a home or office while allowing the utilization of an existing coaxial cable network within the building. SUMMARY A broadband cable network (“BCN”) for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in the BCN is disclosed. The BCN may include a transmitting node within the plurality of nodes where the transmitting node is capable of sending a probe signal to the plurality of nodes, and at least one receiving node within the plurality of nodes in signal communication with the transmitting node. The at least one receiving node is capable of transmitting a first response signal in response to receiving the probe signal. The first response signal includes a first bit-loading modulation scheme determined by the at least one receiving node. The transmitting node is further capable of determining the common bit-loading modulation scheme from the first response signal. The BCN may further include a sub-plurality of receiving nodes within the plurality of nodes wherein the sub-plurality of receiving nodes are capable of transmitting a sub-plurality of response signals in response to receiving the probe signal. The sub-plurality of response signals may include other bit-loading modulation schemes and each bit-loading modulation scheme may be determined by a receiving node within the sub-plurality of receiving nodes. The transmitting node may be capable of determining the common bit-loading modulation scheme from the first response signal and the sub-plurality of response signals. As an example of operation, the BCN is capable of transmitting a probe signal from the transmitting node to the plurality of receiving nodes and receiving a plurality of response signals from the corresponding receiving nodes of the plurality of receiving nodes, wherein each of the response signals includes a bit-loading modulation scheme determined by the corresponding receiving node. The BCN is further capable of determining the common bit-loading modulation scheme from the received plurality of response signals. Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS The invention can be better understood with reference to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views. FIG. 1 shows a block diagram of an example implementation of a known broadband cable system within a building. FIG. 2 shows a block diagram of another example implementation of a known broadband cable system within the building shown in FIG. 1. FIG. 3 shows a block diagram of an example implementation of a broadband cable network (“BCN”) within a building. FIG. 4 shows a functional diagram showing the communication between the different nodes shown in the BCN of FIG. 3 in a unicast mode. FIG. 5 shows another functional diagram showing the communication between the different nodes shown in the BCN of FIG. 3 in a broadcast mode. FIG. 6 shows a block diagram of an example implementation of the BCN shown in FIG. 3 when node A is communicating to node B. FIG. 7 shows a block diagram of another example implementation of the BCN shown in FIG. 3 when node A is communicating to node C. FIG. 8 shows a block diagram of an example implementation of the BCN shown in FIG. 3 when node C is communicating to node B. FIG. 9 shows a plot of the transfer function versus frequency for the channel path between node A and node B and the channel path between node A and node C shown in both FIGS. 6 and 7. FIG. 10A shows a plot of the bit-loading constellation versus carrier number for the channel path between node A and node B shown in FIG. 9. FIG. 10B shows a plot of the bit-loading constellation versus carrier number for the channel path between node A and node C shown in FIG. 9. FIG. 10C shows a plot of the bit-loading constellation versus carrier number for the resulting broadcast channel path between node A and node B and node A and node C based on the constellations shown in FIGS. 10A and 10B. FIG. 11 shows a flowchart illustrating the method performed by the BCN shown in FIG. 3. DETAILED DESCRIPTION In the following description of the preferred embodiment, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. In FIG. 3, a block diagram of an example implementation of a broadband cable network (“BCN”) 300 utilizing common bit-loading within a customer premises (“CP”) 302 is shown. The CP 302 may be a building such as a home or office having a plurality of customer premises equipment (“CPE”) 304, 306 and 308 in signal communication with the BCN 300 via a plurality of corresponding CPE signal paths 310, 312 and 314. The BCN 300 may be in signal communication optionally with an external antenna (not shown), cable provider (not shown) and/or direct broadcast satellite (“DBS”) provider (not shown) via external BCN path 316. The BCN 300 may include a point-of-entry (“POE”) 320, a splitter network 322 and a plurality of nodes such as node A 324, node B 326 and node C 328. The splitter network 322 may be in signal communication with the POE 320, via signal path 330, and the plurality of nodes 324, 326 and 328 via signal paths 332, 334 and 336, respectively. The nodes 324, 326 and 328 may be in signal communication with the CPEs 304, 306 and 308 via signal paths 310, 312 and 314, respectively. In an example operation, the BCN 300 receives input radio frequency (“RF”) signals from optionally the external antenna (not shown), cable provider (not shown) and/or direct broadcast satellite (“DBS”) provider (not shown) at the POE 320 via external BCN path 316. The BCN 300 then passes the input RF signals from POE 320 to the splitter network 322, via signal path 330, and the splitter network 322 splits the input RF signal into split RF signals that are passed to the nodes 324, 326 and 328 via signal paths 332, 334 and 336, respectively. It is appreciated by those skilled in the art that the BCN 300 may be implemented as a coaxial cable network utilizing coaxial cables and components. In FIG. 4, a functional diagram 400 showing the communication between various nodes 402, 404 and 406 corresponding to the nodes in the BCN 300, FIG. 3, is shown. The nodes 402, 404 and 406 may be interconnected between node pairs utilizing corresponding inter-node channels between the node pairs. It is appreciated by those skilled in the art that even if the nodes are individually connected with one another via a signal inter-node channel between the node pairs, each inter-node channel between node pairs may be asymmetric. Therefore, inter-node channels between node A 402, node B 404 and node C 406 may be asymmetric and therefore utilize different bit-loading modulation schemes depending on the direction of the signals between the nodes. As a result, the typically asymmetric inter-node channels between node A 402, node B 404 and node C 406 may be described by the corresponding direction-dependent node channels AB, BA, AC, CA, BC and CB. As an example, node A 402 is in signal communication with node B 404 via signal paths 408 and 410. Signal path 408 corresponds to the AB channel and signal path 410 corresponds to the BA channel. Additionally, node A 402 is also in signal communication with node C 406 via signal paths 412 and 414. Signal path 412 corresponds to the AC channel and signal path 414 corresponds to the CA channel. Similarly, node B 404 is also in signal communication with node C 406 via signal paths 416 and 418. Signal path 416 corresponds to the BC channel and signal path 418 corresponds to the CB channel. In this example, the AB channel corresponds to the channel utilized by node A 402 transmitting to node B 404 along signal path 408. The BA channel corresponds to the reverse channel utilized by node B 404 transmitting to node A 402 along signal path 410. Similarly, the AC channel corresponds to the channel utilized by node A 402 transmitting to node C 406 along signal path 412. The CA channel corresponds to the reverse channel utilized by node C 406 transmitting to node A 402 along signal path 414. Moreover, the BC channel corresponds to the channel utilized by node B 404 transmitting to node C 406 along signal path 416. The CB channel corresponds to the reverse channel utilized by node C 406 transmitting to node B 404 along signal path 418. In example of operation, in order for node A 402 to transmit the same message to both node B 404 and node C 406 using the AB channel along signal path 408 and AC channel along signal path 412, node A 402 will need to transmit (i.e., “unicast”) the same message twice, once to node B 404 and a second time to node C 406 because channel AB and channel AC may utilize different bit-loading modulation schemes. In FIG. 5, another functional diagram 500 showing the communication between various nodes 502, 504 and 506 corresponding to the nodes in the BCN 300, FIG. 3, is shown. In FIG. 5, node A 502 may transmit a message in a broadcast mode (also known as a “multicast” mode) simultaneously to node B 504 and node C 506 using an A-BC channel via signal path 508. The message transmission utilizing the A-BC channel, along signal path 508, is the equivalent of simultaneously transmitting a broadcast message from node A 502 to node B 504 via an AB channel along signal path 510 and to node C 506 via an AC channel along signal path 512 in a fashion that is similar to transmission described in FIG. 4. However, in order to insure that both node B 504 and node C 506 receive the transmissions broadcast signal from node A 502, node A 502 utilizes a bit-loading modulation scheme that is known as a common bit-loaded modulation scheme. The common bit-loaded modulation scheme transmitted via the A-BC channel, along signal path 508, is a combination of the bit-loading modulation scheme transmitted via the AB channel, along signal path 510, and the AC channel, along signal path 512. It is appreciated by those skilled in the art that the different channels typically utilize different bit-loading modulation schemes because the channels are physically and electrically different in the cable network. Physically the channels typically vary in length between nodes and electrically vary because of the paths through and reflections from the various cables, switches, terminals, connections and other electrical components in the cable network. Bit-loading is the process of optimizing the bit distribution to each of the channels to increase throughput. A bit-loading scheme is described in U.S. Utility application Ser. No. 10/322,834 titled “Broadband Network for Coaxial Cable Using Multi-carrier Modulation,” filed Dec. 18, 2002, which is incorporated herein, in its entirety, by reference. The BCN may operate with waveforms that utilize bit-loaded orthogonal frequency division multiplexing (OFDM). Therefore, the BCN may transmit multiple carrier signals (i.e, signals with different carrier frequencies) with different QAM constellations on each carrier. As an example, over a bandwidth of about 50 MHz, the BCN may have 256 different carriers which in the best circumstances would utilize up to 256 QAM modulation carriers. If instead the channel is poor, the BCN may utilize BPSK on all the carriers instead of QAM. If the channel is good in some places and poor in others, the BCN may utilize high QAM in some parts and lower types modulation in others. As an example, in FIG. 6, a block diagram of an example implementation of the BCN 600 is shown. The BCN 600 may be in signal communication with a cable provider (not shown), satellite TV dish (not shown), and/or external antenna (not shown) via a signal path 602 such as a main coaxial cable from the customer premises to a cable connection switch (not shown) outside of the customer premises. The BCN 600 may include a POE 604 and main splitter 606, a sub-splitter 608, nodes A 610, B 612 and C 614, and STBs A 616, B 618 and C 620. Within the BCN 600, the POE 604 may be in signal communication with main splitter 606 via signal path 622. The POE 604 may be the connection point from the cable provider which is located external to the customer premises of the BCN 600. The POE 604 may be implemented as a coaxial cable connector, transformer and/or filter. The main splitter 606 may be in signal communication with sub-splitter 608 and node C 614 via signal paths 624 and 626, respectively. The sub-splitter 608 may be in signal communication with node A 610 and node B 612 via signal paths 628 and 630, respectively. The main splitter 606 and sub-splitter 608 may be implemented as coaxial cable splitters. Node A 610 may be in signal communication with STB A 616 via signal path 632. Similarly, node B 612 may be in signal communication with STB B 618 via signal path 634. Moreover, node C 614 may be in signal communication with STB C 620 via signal path 636. STBs A 616, B 618 and C 620 may be implemented by numerous well known STB coaxial units such as cable television set-top boxes and/or satellite television set-top boxes. Typically, the signal paths 602, 622, 624, 626, 628, 630, 632, 634 and 636 may be implemented utilizing coaxial cables. As an example of operation, if node A 610 transmits a message to node B 612, the message will propagate through two transmission paths from node A 610 to node B 612. The first transmission path 640 travels from node A 610 through signal path 628, sub-splitter 608 and signal path 630 to node B 612. The second transmission path includes transmission sub-paths 642 and 644. The first sub-path 642 travels from node A 610 through signal path 628, sub-splitter 608, signal path 624, main splitter 606 and signal path 622 to POE 604. The second sub-path 644 travels from POE 604, through signal path 622, main splitter 606, signal path 624, sub-splitter 608 and signal path 630. The first transmission path 640 is typically very lossy and experiences a high amount of attenuation because of the isolation between the outputs of sub-splitter 608. The second transmission path, however, does not experience the attenuation of the first transmission path 640. The second transmission path results from the transmission of message signal 646 from node A 610 to the POE 604 along the first sub-path 642 which results in a reflected message signal 648 from the POE 604. The reflected message signal 648 results from impedance mismatches between the POE 604 and the rest of the BCN 600. As another example, in FIG. 7, another block diagram of an example implementation of the BCN 700 is shown. Similar to FIG. 6, in FIG. 7, the BCN 700 may be in signal communication with a cable provider (not shown), satellite TV dish (not shown), and/or external antenna (not shown) via a signal path 702 such as a main coaxial cable from the customer premises to a cable connection switch (not shown) outside of the customer premises. The BCN 700 may include a POE 704 and main splitter 706, a sub-splitter 708, nodes A 710, B 712 and C 714, and STBs A 716, B 718 and C 720. Within the BCN 700, the POE 704 may be in signal communication with main splitter 706 via signal path 722. The POE 704 may be the connection point from the cable provider which is located external to the customer premises of the BCN 700. The POE 704 may be implemented as a coaxial cable connector, transformer and/or filter. The main splitter 706 may be in signal communication with sub-splitter 708 and node C 714 via signal paths 724 and 726, respectively. The sub-splitter 708 may be in signal communication with node A 710 and node B 712 via signal paths 728 and 730, respectively. The main splitter 706 and sub-splitter 708 may be implemented as coaxial cable splitters. Node A 710 may be in signal communication with STB A 716 via signal path 732. Similarly, node B 712 may be in signal communication with STB B 718 via signal path 734. Moreover, node C 714 may be in signal communication with STB C 720 via signal path 736. STBs A 716, B 718 and C 720 may be implemented by numerous well known STB coaxial units such as cable television set-top boxes and/or satellite television set-top boxes. Typically, the signal paths 702, 722, 724, 726, 728, 730, 732, 734 and 736 may be implemented utilizing coaxial cables. As an example of operation, if node A 710 transmits a message to node C 714, the message will propagate through two transmission paths from node A 710 to node C 714. The first transmission path 740 travels from node A 710 through signal path 728, sub-splitter 708, signal path 724, main splitter 706 and signal path 726 to node C 714. The second transmission path includes transmission sub-paths 742 and 744. The first sub-path 742 travels from node A 710 through signal path 728, sub-splitter 708, signal path 724, main splitter 706 and signal path 722 to POE 704. The second sub-path 744 travels from POE 704, through signal path 722, main splitter 706, and signal path 726 to node C 714. The first transmission path 740 is typically very lossy and experiences a high amount of attenuation because of the isolation between the outputs of sub-splitter 708 and main splitter 706. The second transmission path, however, does not experience the attenuation of the first transmission path 740. The second transmission path results from the transmission of message signal 746 from node A 710 to the POE 704 along the first sub-path 742 which results in a reflected message signal 748 from the POE 704. The reflected message signal 748 results from mismatches between the POE 704 and therest of the BCN 700. As still another example, in FIG. 8, another block diagram of an example implementation of the BCN 800 is shown. Similar to FIGS. 6 and 7, in FIG. 8, the BCN 800 may be in signal communication with a cable provider (not shown), satellite TV dish (not shown), and/or external antenna (not shown) via a signal path 802 such as a main coaxial cable from the customer premises to a cable connection switch (not shown) outside of the customer premises. The BCN 800 may include a POE 804 and main splitter 806, a sub-splitter 808, nodes A 810, B 812 and C 814, and STBs A 816, B 818 and C 820. Within the BCN 800, the POE 804 may be in signal communication with main splitter 806 via signal path 822. The POE 804 may be the connection point from the cable provider which is located external to the customer premises of the BCN 800. The POE 804 may be implemented as a coaxial cable connector, transformer and/or filter. The main splitter 806 may be in signal communication with sub-splitter 808 and node C 814 via signal paths 824 and 826, respectively. The sub-splitter 808 may be in signal communication with node A 810 and node B 812 via signal paths 828 and 830, respectively. The main splitter 806 and sub-splitter 808 may be implemented as coaxial cable splitters. Node A 810 may be in signal communication with STB A 816 via signal path 832. Similarly, node B 812 may be in signal communication with STB B 818 via signal path 834. Moreover, node C 814 may be in signal communication with STB C 820 via signal path 836. STBs A 816, B 818 and C 820 may be implemented by numerous well known STB coaxial units such as cable television set-top boxes and/or satellite television set-top boxes. Typically, the signal paths 802, 822, 824, 826, 828, 830, 832, 834 and 836 may be implemented utilizing coaxial cables. As an example of operation, if node C 814 transmits a message to node B 812, the message will propagate through two transmission paths from node C 814 to node B 812. The first transmission path 840 travels from node C 814 through signal path 826, main splitter 806, signal path 824, sub-splitter 808 and signal path 830 to node B 812. The second transmission path includes two transmission sub-paths 842 and 844. The first sub-path 842 travels from node C 814 through signal path 826, main splitter 806, and signal path 822 to POE 804. The second sub-path 844 travels from POE 804, through signal path 822, main splitter 806, signal path 824, sub-splitter 808 and signal path 830 to node B 812. The first transmission path 840 is typically very lossy and experiences a high amount of attenuation because of the isolation between the outputs of sub-splitter 808 and main splitter 806. The second transmission path, however, does not experience the attenuation of the first transmission path 840. The second transmission path results from the transmission of message signal 846 from node C 814 to the POE 804 along the first sub-path 842 which results in a reflected message signal 848 from the POE 804. The reflected message signal 848 results from mismatches between the POE 804 and rest of the BCN 800. In FIG. 9, a plot 900 of the maximum bit-loading constellation 902 versus frequency 904 is shown for the channel path utilized by node A to transmit to node B and the channel path utilized by node A to transmit to node C. Line 906 represents the AB channel and line 908 represents the AC channel. The AB channel has a null 910 that represents the reflection distance from the POE to node B. The AC channel has nulls 912 and 914. Null 912 represents the reflection distance from the POE to node C and null 914 represents a harmonic that is a multiple value of the value of null 912. In general, the nulls are caused by the properties, e.g., amplitudes and time delays, that are unique to each transmission path in the network. Returning to FIG. 5, the BCN, in order to insure that both node B 504 and node C 506 are able to receive a broadcast signal transmitted from node A 502, utilizes a bit-loading modulation scheme that is known as the common bit-loaded modulation scheme. The common bit-loaded modulation scheme transmitted via the A-BC channel, along signal path 508, is a combination of the bit-loading modulation scheme transmitted via the AB channel, along signal path 510, and the AC channel, along signal path 512. Therefore, in FIG. 10A, a plot 1000 of carrier frequency signals of various bit-loading constellations 1002 versus carrier number 1004 for the AB channel path between node A and node B is shown. Line 1006 represents the AB channel and follows an envelope of the constellation sizes of the 8 different carrier number signals within the AB channel. As an example, within the AB channel carrier number signals 1 and 8 may transmit at a constellation size of 256 QAM, carrier number signals 2, 3 and 7 may transmit at a constellation size of 128 QAM, carrier number signals 4 and 6 may transmit at a constellation size of 64 QAM, and carrier number signal 5 may be OFF (i.e., no carrier signal of any constellation size may be transmitted because of the null in the channel characteristics). Similarly in FIG. 10B, a plot 1008 of carrier frequency signals of various bit-loading constellations 1010 versus carrier number 1012 for the AC channel path between node A and node C is shown. Line 1014 represents the AC channel and follows an envelope of the constellation sizes of the 8 different carrier number signals within the AC channel. As an example, within the AC channel carrier number signals 1, 2, 4, 6 and 8 may transmit at a constellation size of 128 QAM, carrier number signal 5 may transmit at a constellation size of 256 QAM, and carrier number signals 3 and 7 may be OFF (again, no carrier signals may be transmitted because of nulls in the channel characteristics). In FIG. 10C, a plot 1016 of the common carrier frequency signals of various bit-loading constellations 1018 versus carrier number 1020 for the A-BC channel path between node A and nodes B and C is shown. In this example, plot 1016 shows that within the A-BC channel, carrier number signals 1, 2 and 8 may transmit at a constellation size of 128 QAM, carrier number signals 4 and 6 may transmit at a constellation size of 64 QAM, and carrier number signals 3, 5 and 7 are OFF. These carrier number signal values are the result of comparing the carrier number signals from the AB channel in FIG. 10A and the corresponding carrier number signals from the AC channel in FIG. 10B and choosing the lowest corresponding modulation value for each carrier number. The resulting common carrier frequency signals in FIG. 10C graphically represent signals utilizing the common bit-loaded modulation scheme. These signals would be able to transmit information from node A to node B and node C simultaneously. FIG. 11 shows a flowchart 1100 illustrating the method performed by the BCN shown in FIG. 3. In FIG. 11, the process starts in step 1102. In step 1104, a transmitting node transmits a probe signal from the transmitting node to a plurality of receiving nodes. In response, the receiving nodes receive the probe signal from the transmitting node. In step 1106, a receiving node of the plurality of receiving nodes receives the probe signal through the appropriate channel path of transmission. The receiving node then determines the transmission characteristics of the channel path from the transmitting node to the receiving node in step 1108 and in response to the determined transmission characteristics of the channel path, the receiving node determines a bit-loaded modulation scheme for the transmission characteristics of the channel path in step 1110. It is appreciate by those skilled in the art that the transmission characteristics of the channel path may be determined by measuring the metric values of the channel path. Examples of the metric values may include the signal-to-noise ratio (also known as the “SNR” and “S/N”) and/or the bit-error rate (“BER”) or product error rate (PER), or power level or similar measurement of the received signal at the corresponding remote device. Additionally, other signal performance metric values are also possible without departing from the scope of the invention. The receiving node then, in step 1112, transmits a response signal to the transmitting node, informing the transmitting node of the recently-determined bit-loaded modulation scheme. The transmitting node then receives a plurality of response signals, in step 1114, from the corresponding receiving nodes wherein each of the response signals informs the transmitting node of the corresponding bit-loaded modulation scheme determined by each of the plurality of receiving nodes. In response to receiving the plurality of response signals, the transmitting node, in step 1116, compares the plurality of bit-loaded modulation schemes from the corresponding received plurality of response signals and, in step 1118, determines the common bit-loaded modulation scheme. Once the transmitting node determines the common bit-loaded modulation scheme, the transmitting node, in step 1120, transmits a broadcast signal relaying the common bit-loaded modulation scheme to the plurality of receiving nodes. This broadcast signal may either contain handshake information from the transmitting node to the plurality of receiving nodes or it may actually be a communication message containing information such as video, music, voice and/or other data. In decision step 1122, if all the nodes in BCN have performed the handshake process that determines the common bit-loaded modulation scheme in steps 1102 through 1120, the handshake process is complete and process ends in step 1124, at which time the BCN may begin to freely transmit information between the various nodes. If instead, there are still nodes in the BCN that have not performed the handshake process that determines the common bit-loaded modulation scheme in steps 1102 through 1120, the process then returns to step 1126. In step 1126, the BCN selects the next node in the BCN and the process steps 1102 to 1122 repeat again. Once all the nodes in the BCN have preformed the handshake process, the handshake process is complete and process ends in step 1124 at which time the BCN may begin to freely transmit information between the various nodes. The process in FIG. 11 may be performed by hardware or software. If the process is performed by software, the software may reside in software memory (not shown) in the BCN. The software in software memory may include an ordered listing of executable instructions for implementing logical functions (i.e., “logic” that may be implemented either in digital form such as digital circuitry or source code or in analog form such as analog circuitry or an analog source such as an analog electrical, sound or video signal), may selectively be embodied in any computer-readable (or signal-bearing) medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that may selectively fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “computer-readable medium” and/or “signal-bearing medium” is any means that may contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium may selectively be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples, that is “a non-exhaustive list” of the computer-readable media, would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a RAM (electronic), a read-only memory “ROM” (electronic), an erasable programmable read-only memory (EPROM or Flash memory) (electronic), an optical fiber (optical), and a portable compact disc read-only memory “CDROM” (optical). Note that the computer-readable medium may even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory. While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention The invention relates to broadband communication networks, and in particular to broadband communication networks utilizing coaxial cable. 2. Related Art The worldwide utilization of external television (“TV”) antennas for receiving broadcast TV, and of cable television and satellite TV is growing at a rapid pace. These TV signals from an external TV antenna, cable TV and satellite TV (such as from direct broadcast satellite “DBS” system) are usually received externally to a building (such as a home or an office) at a point-of-entry (“POE”). There may be multiple TV receivers and/or video monitors within the building and these multiple TV receivers may be in signal communication with the POE via a broadband cable network that may include a plurality of broadband cables and broadband cable splitters. Generally, these broadband cable splitters distribute downstream signals from the POE to various terminals (also known as “nodes”) in the building. The nodes may be connected to various types of customer premise equipment (“CPE”) such as cable converter boxes, televisions, video monitors, cable modems, cable phones and video game consoles. Typically, these broadband cables and broadband cable splitters are implemented utilizing coaxial cables and coaxial cable splitters, respectively. Additionally, in the case of cable TV or satellite TV, the multiple TV receivers may be in signal communication with the broadband cable network via a plurality of cable converter boxes, also known as set-top boxes (“STBs”), that are connected between the multiple TV receivers and the broadband cable network via a plurality of network nodes. Typically, a STB connects to a coaxial cable from a network node (such as the wall outlet terminal) to receive cable TV and/or satellite TV signals. Usually, the STB receives the cable TV and/or satellite TV signals from the network node and converts them into tuned TV signals that may be received by the TV receiver and/or video signals that may be received by a video monitor. In FIG. 1 , an example known broadband cable network 100 (also known as a “cable system” and/or “cable wiring”) is shown within a building 102 (also known as customer premises or “CP”) such as a typical home or office. The broadband cable system 100 may be in signal communication with an optional cable service provider 104 , optional broadcast TV station 106 , and/or optional DBS satellite 108 , via signal path 110 , signal path 112 and external antenna 114 , and signal path 116 and DBS antenna 118 , respectively. The broadband cable system 100 also may be in signal communication with optional CPEs 120 , 122 and 124 , via signal paths 126 , 128 and 130 , respectively. In FIG. 2 , another example known broadband cable system is shown within a building (not shown) such as a typically home. The cable system 200 may be in signal communication with a cable provider (not shown), satellite TV dish (not shown), and/or external antenna (not shown) via a signal path 202 such as a main coaxial cable from the building to a cable connection switch (not shown) outside of the building. The cable system 200 may include a POE 204 and main splitter 206 , a sub-splitter 208 , and STBs A 210 , B 212 and C 214 . Within the cable system 200 , the POE 204 may be in signal communication with main splitter 206 via signal path 216 . The POE 204 may be the connection point from the cable provider which is located external to the building of the cable system 200 . The POE 202 may be implemented as a coaxial cable connector, transformer and/or filter. The main splitter 206 may be in signal communication with sub-splitter 208 and STB A 210 via signal paths 218 and 220 , respectively. The sub-splitter 208 may be in signal communication with STB B 212 and STB C 214 via signal paths 222 and 224 , respectively. The main splitter 206 and sub-splitter 208 may be implemented as coaxial cable splitters. The STB A 210 , B 212 and C 214 may be implemented by numerous well known STB coaxial units such as cable television set-top boxes and/or satellite television set-top boxes. Typically, the signal paths 202 , 216 , 218 , 220 , 222 and 224 may be implemented utilizing coaxial cables. In an example operation, the cable system 200 would receive CATV, cable and/or satellite radio frequency (“RF”) TV signals 226 via signal path 202 at the POE 204 . The POE 204 may pass, transform and/or filter the received RF signals to a second RF signal 228 that may be passed to the main splitter 206 via signal path 216 . The main splitter 206 may then split the second RF signal 228 into split RF signals 230 and 232 . The split RF signal 230 is then passed to the sub-splitter 208 and the split RF signal 232 is passed to the STB A 210 via signal paths 218 and 220 , respectively. Once the split RF signal 232 is received by the STB A 210 , the STB A 210 may convert the received split RF signal 232 into a baseband signal 238 that may be passed to a video monitor (not shown) in signal communication with the STB A 210 . Once the split RF signal 230 is received by the sub-splitter 208 , the sub-splitter 208 splits the received split RF signal 230 into sub-split RF signals 234 and 236 that are passed to STB B 212 and STB C 214 via signal paths 222 and 224 , respectively. Once the sub-split RF signals 234 and 236 are received by the STB B 212 and STB C 214 , respectively, the STB B 212 and STB C 214 may convert the received sub-split RF signals 234 and 236 into baseband signals 240 and 242 , respectively, that may be passed to video monitors (not shown) in signal communication with STB B 212 and STB C 214 . As the utilization of the numbers and types of CPEs in buildings increase (such as the number of televisions, video monitors, cable modems, cable phones, video game consoles, etc., increase in a typical home or office environment), there is a growing need for different CPEs to communicate between themselves in a network type of environment within the building. As an example, users in a home may desire to play network video games between different rooms in home environment utilizing the coaxial cable network installed throughout the home. Additionally, in another example, users in a home may want to share other types of digital data (such video and/or computer information) between different rooms in a home. Unfortunately, most broadband cable networks (such as the examples shown in both FIG. 1 and FIG. 2 ) presently utilized within most existing buildings are not configured to allow for easy networking between CPEs because most broadband cable networks utilize broadband cable splitters that are designed to split an incoming signal from the POE into numerous split signals that are passed to the different nodes in different rooms. As an example, in a typical home the signal splitters are commonly coaxial cable splitters that have an input port and multiple output ports. Generally, the input port is known as a common port and the output ports are known as tap ports. These types of splitters are generally passive devices and may be constructed using lumped element circuits with discrete transformers, inductors, capacitors, and resistors and/or using strip-line or microstrip circuits. These types of splitters are generally bi-directional because they may also function as signal combiners, which sum the power from the multiple tap ports into a single output at the common port. However, presently many CPEs utilized in modern cable and DBS systems have the ability to transmit as well as receive. If a CPE is capable of transmitting an upstream signal, the transmitted upstream signal from that CPE typically flows through the signal splitters back to the POE and to the cable and/or DBS provider. In this reverse flow direction, the signal splitters function as signal combiners for upstream signals from the CPEs to the POE. Usually, most of the energy from the upstream signals is passed from the CPEs to the POE because the splitters typically have a high level of isolation between the different connected terminals resulting in significant isolation between the various CPEs. The isolation creates a difficult environment to network between the different CPEs because the isolation results in difficulty for transmitting two-way communication data between the different CPEs. Unfortunately, CPEs are becoming increasingly complex and a growing number of users desire to connect these multiple CPEs into different types of networks. Therefore, there is a need for a system and method to connect a variety of CPEs into a local network, such as local-area network (“LAN”), within a building such as a home or office. Additionally, there is a need for a system and method to connect a variety of CPEs into a local network, such as a LAN, within a building such as a home or office while allowing the utilization of an existing coaxial cable network within the building. | <SOH> SUMMARY <EOH>A broadband cable network (“BCN”) for determining a common bit-loading modulation scheme for communicating between a plurality of nodes in the BCN is disclosed. The BCN may include a transmitting node within the plurality of nodes where the transmitting node is capable of sending a probe signal to the plurality of nodes, and at least one receiving node within the plurality of nodes in signal communication with the transmitting node. The at least one receiving node is capable of transmitting a first response signal in response to receiving the probe signal. The first response signal includes a first bit-loading modulation scheme determined by the at least one receiving node. The transmitting node is further capable of determining the common bit-loading modulation scheme from the first response signal. The BCN may further include a sub-plurality of receiving nodes within the plurality of nodes wherein the sub-plurality of receiving nodes are capable of transmitting a sub-plurality of response signals in response to receiving the probe signal. The sub-plurality of response signals may include other bit-loading modulation schemes and each bit-loading modulation scheme may be determined by a receiving node within the sub-plurality of receiving nodes. The transmitting node may be capable of determining the common bit-loading modulation scheme from the first response signal and the sub-plurality of response signals. As an example of operation, the BCN is capable of transmitting a probe signal from the transmitting node to the plurality of receiving nodes and receiving a plurality of response signals from the corresponding receiving nodes of the plurality of receiving nodes, wherein each of the response signals includes a bit-loading modulation scheme determined by the corresponding receiving node. The BCN is further capable of determining the common bit-loading modulation scheme from the received plurality of response signals. Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. | 20040712 | 20110215 | 20050526 | 67384.0 | 1 | SINKANTARAKORN, PAWARIS | BROADBAND CABLE NETWORK UTILIZING COMMON BIT-LOADING | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,889,996 | ACCEPTED | Sputtering cathode for coating processes | A sputtering cathode (1) for coating processes in a vacuum chamber (18) comprises one at least single-piece target plate (2) mounted on a metallic diaphragm (3). On the side of the diaphragm (3) facing away from the target plate (2) is disposed a cooling agent channel with an inflow line (9) and an outflow line (10) for a cooling agent and a hollow space (7) for at least one magnet system (5). The magnet system (5) is disposed in a supporting tub (6) sealed against the diaphragm (3) and not exposed to the cooling agent. The entire configuration is disposed on a supporting structure (12). In order to improve the heat transfer from the target plate (2) to the cooling agent in simple, efficient and cost-effective manner and to avoid the hazard of the cooling agent penetrating into the vacuum chamber, the invention provides that a) the supporting structure (12) for the sputtering cathode (1) comprises a hollow body (13), which is closed gas-tight against the interior space of the vacuum chamber (18) and which connects the hollow space (7) encompassing the magnet system (5) with the atmosphere outside of the vacuum chamber (18), b) the cooling agent channel is implemented as a conduit (4) closed on its cross sectional periphery with at least one flat side (4a) in thermally conducting connection with the diaphragm (3), and that c) the diaphragm (3) and the surfaces of the conduit (4) facing away from the diaphragm (3) are exposed via said supporting structure (12) to the atmospheric pressure outside of the vacuum chamber (18). | 1-8. (canceled) 9. A sputtering cathode for coating processes in a vacuum chamber comprising an at least single-piece target plate mounted on a metallic diaphragm on whose side facing away from a target plate are disposed a cooling agent channel with an inflow line and an outflow line for a cooling agent and a hollow space for at least one magnet system, the magnet system being disposed in a supporting tub sealed against the diaphragm and not contacted by the cooling agent and the entire configuration being disposed on a supporting structure, wherein the supporting structure for the sputtering cathode comprises a hollow body, which is closed gas-tight against the interior space of the vacuum chamber and which connects the hollow space encompassing the magnet system with the atmosphere outside of the vacuum chamber), the cooling agent channel is a conduit closed on its cross sectional periphery with at least one flat side in thermally conducting connection with the diaphragm, and the diaphragm and the surfaces of the conduit facing away from the diaphragm are exposed via said supporting structure to the atmospheric pressure outside of the vacuum chamber. 10. The sputtering cathode as claimed in claim 9, wherein the conduit for the cooling agent has a rectangular cross section, whose one long side is in thermally conducting connection with the diaphragm. 11. The sputtering cathode as claimed in claim 9, wherein the conduit for the cooling agent is connected with the diaphragm through a joining process. 12. The sputtering cathode as claimed in claim 9, wherein the hollow body of the supporting structure is fastened on a mounting plate, which is fastened on a wall of the vacuum chamber, which, within the connection site of the mounting plate, has an opening with respect to the ambient atmosphere. 13. The sputtering cathode as claimed in claim 12, wherein at both ends of the conduit orthogonal tubular fittings are connected terminating in elbows and from which connecting lines are carried through the hollow body of the supporting structure to the ambient atmosphere. 14. The sputtering cathode as claimed in claim 9, wherein the supporting tub of the sputtering cathode is connected vacuum-tight with the hollow body of the supporting structure via a support body closed on the circumference. 15. The sputtering cathode as claimed in claim 14, wherein the supporting tub of the sputtering cathode and a mounting for target plate is encompassed by a housing which by means of a first frame, extends over the mounting of the target plate and, by a second frame, extends under the supporting tub up into the proximity of the support body. 16. The sputtering cathode as claimed in claim 9, wherein the conduit extends within the sputtering cathode approximately centrally between the different poles of the magnet system. | The invention relates to a sputtering cathode for coating processes in a vacuum chamber, with an at least single-piece target plate mounted on a metallic diaphragm, on the side of which, facing away from the target, are disposed a cooling agent channel with an inflow line and an outflow line for a cooling agent and a hollow space for at least one magnet system, the magnet system being disposed in a supporting tub, sealed against the diaphragm, and not exposed to the cooling fluid, and the entire configuration being disposed on a supporting structure. Such sputtering cathodes are high-power sputtering cathodes and are also referred to as magnetron cathodes. Behind the target plate is disposed a magnet system, which generates on the opposing sputtering surface a closed magnetic tunnel in which the plasma of an ionized gas required for the sputtering process is enclosed. Thereby, on the one hand, the sputter rate is increased by the twenty to thirty-fold value compared to a magnet-free cathode, but, on the other hand, the energy density is focused onto a region beneath the magnetic tunnel and, consequently, also the erosion rate of the material of the target plate and the heat delivery into it. This forces a short-term change-out cycle of the target plate and an extremely efficient cooling system. The problems increase with the size of the sputtering cathode. EP 0 476 652 B1 discloses closing off circular, relatively small cathode housings, in which are disposed magnet systems, with respect to the vacuum coating chamber through a relatively thick cathode plate (6 to 7 mm). Through this cathode plate and an encircling toroidal sealing ring the cathode housing, in which is disposed a cooling fluid flushing around the magnets, is closed off against the coating chamber. The patent expressly states that the penetration of the cooling fluid into the coating chamber leads to product rejects, since thereby the coating atmosphere—either inert gas or reactive gas—is spoiled. As the cooling fluid are specified for example water and ethylene glycol. The cathode plate can be implemented either homogeneously or laminated and be comprised of a base plate of aluminum, the target proper and a reinforcement layer of copper, optionally supplemented by a heating layer for outgassing the cathode before the coating. The stated cathode diameters reach up to 290 mm. However, a significant disadvantage is comprised in that in order to change the cathode plate, it is necessary to remove the cooling fluid, detach and clean the seal, before, after considerable loss of time, the system can again be taken into operation in the reverse direction. The same document also discloses a base plate, in which, close behind the target material to be sputtered, closed cooling agent channels are disposed. However, here the hazard exists that if monitoring is neglected, the target material is etched through and the base plate is etched up to the cooling agent channels. This, in turn, entails the hazard of the cooling agent penetrating into the coating chamber. Means for establishing a connection of the cooling agent channels with the environment are not disclosed. From DE 43 01 516 A1 is known a sputtering cathode of the above described species, in which a cooling agent channel is formed between an elastic diaphragm and a solid tub with an encircling hollow space and two encircling seals. Over the entire face of the diaphragm are disposed targets or target parts. The cooling agent channel and the target(s) are secured in place with alternatingly disposed screw connections from below and above, which, on the one hand, act via claws or nuts on the diaphragm with the tub and, on the other hand, onto the target margins. The magnets are here disposed outside of the cooling agent. However, since the entire sputtering cathode is disposed within a vacuum chamber (not shown), possibly leaking cooling agent could enter the vacuum chamber and negatively affect the coating process. From DE 196 22 605 A1 and DE 196 22 606 C2 is known to dispose between the magnet system and the target plate at least one sheet metal blank of a magnetically conductive material in order to force onto the field lines, forming a magnetic tunnel for the plasma effecting the sputtering, a flatter course in order to widen the erosion trough in the target plate and to increase the [rate] efficiency of the material. In addition, DE 196 22 606 C2 also discloses a target base plate supporting the target. The invention therefore addresses the problem of improving in a sputtering cathode of the species described in the introduction the heat transfer from target to cooling agent in simple, efficient, and cost-effective manner and to avoid the hazard of the cooling agent or its vapors penetrating into the vacuum chamber and of the impairment of the coating process. The formulated problem is solved in a sputtering cathode of the species described in the introduction according to the invention thereby that a) the supporting structure for the sputtering cathode comprises a hollow body, which is closed gas-tight against the interior space of the vacuum chamber and which connects the hollow space encompassing the magnet system with the atmosphere outside of the vacuum chamber, b) the cooling agent channel is implemented as a conduit closed on its cross section periphery with at least one flat side, which [flat side] is in a thermally conducting connection with the diaphragm, and that c) the diaphragm and the surfaces of the conduit facing away from the diaphragm, via said supporting structure are exposed to the atmospheric pressure obtaining outside the vacuum chamber. Through the invention, in a sputtering cathode of the species described in the introduction, the heat transfer from target to cooling agent in simple, efficient and cost-effective manner is improved and the hazard of the cooling agent or its vapors penetrating into the vacuum chamber and the impairment of the coating process are avoided. In the course of further embodiments of the invention it is especially advantageous if, either individually or in combination the conduit for the cooling fluid has a rectangular cross section, whose one long side forms with the diaphragm a heat conducting connection, the conduit for the cooling fluid is connected with the diaphragm through joining process, the hollow body of the supporting structure is fastened on a mounting plate which is fastened on a wall of the vacuum chamber, which, within the connection site of the mounting plate, has an opening with respect to the ambient atmosphere, at both ends of the conduit orthogonal tubular fittings are connected terminating in elbows, and from which connection lines are guided through the hollow body of the supporting structure up to the ambient atmosphere, the supporting tub of the sputtering cathode via a support body closed on the periphery vacuum-tight is connected with the hollow body of the supporting structure, the supporting tub of the sputtering cathode and the mountings for the target plate(s) are encompassed by a housing, which extends by means of a first frame over the mountings of the target plate(s) and by means of a second frame extends under the supporting tub up into the proximity of the support body and/or if the conduit extends within the sputtering cathode approximately entrally between the different poles of the magnet system. In the following an embodiment example of the subject matter of the invention and its operational function and advantages will be explained in further detail in conjunction with a rectangular cathode according to FIGS. 1 to 6. In the drawing depict: FIG. 1 a vertical section through a complete cathode system with supporting structure within a cut-out of a vacuum chamber with a cutting plane perpendicular to the longitudinal axis of the cathode, FIG. 2 a partial vertical longitudinal section through that end of the cathode system at which the conduit for the cooling agent supply is connected, however without supporting structure and at an enlarged scale, FIG. 3 the other end of the cathode system relative to FIG. 2, at which the conduit is turned around by 180 degrees, FIG. 4 a top view onto the magnet system after removal of the target plate, at a reduced scale, FIG. 5 a top view onto one end of the cathode system, and FIG. 6 an orthogonal cross section through the cathode system according to FIGS. 2, 3 and 5. It should be emphasized at the outset that the sputtering cathode is shown as a rectangular cathode whose length for large-area coating by means of a relative longitudinal movement of glass can be several meters, however, that the structural principle can readily be employed for round cathodes of any size. It is understood that the application is also possible in the converse, i.e. in “over-head position” or also in any oblique positions, for example in the case of foil coating on cylinders. FIG. 1 depicts a sputtering cathode 1, whose functionally essential part is a target plate 2, which during operation supplies the coating material or a component thereof, depending on whether the method is carried out in an inert (for example argon) or a reactive atmosphere (for example oxygen or nitrogen). The target plate 2 can be structured monolithically or be comprised of layers, which is known per se. Behind the target plate 2 is first disposed an elastic diaphragm 3 of metal, which also can be structured of a single layer or of multiple layers. One of the layers 3a can be comprised, for example, of iron, steel and/or high-grade steel and the other layer 3b of copper. The layer 3a serves for the purpose of flattening the arcuate course of the field lines, which enclose a magnetic tunnel, in order to widen the erosion troughs in the target plate and to increase the material [rate] efficiency. In heat-conducting connection with layer 3b is an approximately U-shaped cooling agent channel of a conduit 4, whose cross section is rectangular and whose upper flat side 4a is connected with the target plate 2, such that the connection conducts heat well. This connection is preferably established through a joining method from the group soldering, welding or adhering with a thermally conducting adhesive agent. Spaced behind it is disposed a magnet system 5 (FIG. 4), of which here only the outer magnet row 5a is shown. Layers 3a and 3b have a total thickness of 2 to 4 mm, but are preferably not fixedly connected with one another in order to keep the elasticity through relative displaceability as large as possible. Diaphragm 3 and magnet system 5 are held by a supporting tub 6, which comprises a correspondingly shaped step-form hollow space 7 and a through-opening 8 for an inflow line 9 and an outflow line 10 for a cooling fluid. The entire configuration is mounted via a peripherally closed support body 11 on a supporting structure 12, which comprises a hollow body 13 and encompasses a cuboidal hollow space 14 with an upper opening 14a. This hollow space 14 is connected with the external atmosphere in a manner to be described further in the following. The short thick arrows directed against the diaphragm 3 and the conduit 4 symbolize the contact forces through the outer atmospheric pressure, which penetrates up to the hollow space 7 of the supporting tub 6. Lines 9 and 10 are implemented as tubular fittings 9a and 10a and terminate in elbows 15, to which additional lines are connected, not shown here, which are guided in the longitudinal direction through the hollow space 14 to the outside atmosphere. To maintain the distance between the tubular fittings 9a and 10a serve clamping devices 16 and 17. The seals for the vacuum-tight closure between the coating and the external atmosphere are indicated by black rectangles and are not labeled with a reference number. The configuration described up to this point is disposed in a vacuum chamber 18, of which here only a cut-out and the bottom 18a are depicted. For this purpose the hollow body 13 of the supporting structure 12 is fastened on a mounting plate 19, which is fastened vacuum-tight on a wall of the vacuum chamber 18. Said wall includes within the mounting plate 19 or the connection site an opening, not shown here, with respect to the ambient or external atmosphere. Shown is further that the sputtering cathode 1 with its supporting tub 6 is encompassed by a housing 20, which extends by means of a first upper frame 20a over the mountings and margins of the target plate 2 and, by means of a second lower frame 20b, extends beneath the supporting tub 6 up into the proximity of the support body 11. FIG. 2 to 6 show under maintenance of the previuos enumeratin the following: FIG. 2 shows a partial vertical longitudinal section through that end of the cathode system, at which the tubular fittings 9a and 10a for the cooling agent supply to the conduit 4 are connected, however, without supporting structure 12. The longitudinal section extends through the central magnet row 5b, previously not shown, a tension bolt 21 through the clamping device 16 and a partial circumference of one of the seals 22, a partition wall 23 between the connection-side ends of the conduit 4 and—in dashed lines—one of the horizontal connection lines 24 carried to the external atmosphere. FIG. 3 shows the other end of the cathode system with respect to FIG. 2, at which the conduit 4 is turned around by 180 degrees. A step-form recess 25 serves for receiving a, not shown, supporting device with respect to the supporting structure 12. FIG. 4 is a top view onto the magnet system 5, respectively 5a and 5b, after the target plate 2 has been removed. This magnet system generates a magnetic field penetrating through the target plate 2 with arcuate field lines and with a race track-like configuration, which encloses a congruous plasma formed through a potential difference between the sputtering cathode 1 and a, not shown, anode, which [plasma] is excited through an anode body and/or through a, also not shown, substrate holder at ground potential. Said plasma under high energy charging sputters the material of the target plate 2 and ensures a condensation of the sputtered-off material or a compound thereof on the substrates. However, such causal relationships which necessitate efficient cooling are known and therefore not further discussed. FIG. 5 is a top view onto one end of the cathode system. The target plate 2 is secured due to a Z-shaped implementation of the partition lines through a frame of claw cleats bolted to the supporting tub 6, which also clamp in the diaphragm 3 against the supporting tub 6. FIG. 6 depicts at an enlarged scale, compared to FIG. 1, an orthogonal cross section through the cathode system according to FIGS. 2, 3 and 5. Shown again through thick black arrows are the force effects of the external atmospheric pressure on the diaphragm 3 and the conduit 4. The outer magnet rows 5a are disposed mirror symmetrical to the inner magnet row 5b. In the interspace 7 the two shanks of the conduit 4 are disposed spaced apart from the outer magnet rows 5a and to the central magnet row 5b. This permits an extremely efficient cooling of diaphragm 3 and target plate 2 and to maintain them at constant temperature after heating. It is additionally emphasized that between the upper delimiting surfaces of the magnet rows 5a and 5b, spacings or air gaps are also formed. LIST OF REFERENCE SYMBOLS 1 Sputtering cathode 2 Target plate 3 Diaphragm 3a Layer 3b Layer 4 Conduit 4a Flat side 5 Magnet system 5a Outer magnet row 5b Inner magnet row 6 Supporting tub 7 Hollow space 8 Through-opening 9 Inflow line 9b Tubular fitting 10 Outflow line 10 a Tubular fitting 11 Support body 12 Supporting structure 13 Hollow body 14 Hollow space 14a Opening 15 Elbow 16 Clamping device 17 Clamping device 18 Vacuum chamber 18a Bottom 19 Mounting plate 20 Housing 20a Frame 20b Frame 21 Tension bolt 22 Seals 23 Partition wall 24 Connection line 25 Recess 26 Claw cleats | 20040713 | 20100810 | 20051222 | 68083.0 | 0 | BAND, MICHAEL A | SPUTTERING CATHODE FOR COATING PROCESSES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,115 | ACCEPTED | LENS MODULE AND ASSEMBLING METHOD THEREOF | A lens module has a module body and a mating receptacle. The module body has a lens unit and an image sensing and processing unit, the image sensing and processing unit receiving light beams from the lens unit and producing an image signal. The mating receptacle is made of insulating material, which is detachably engaged with the module body and has conductive terminals formed therein for transmitting the image signal. An assembling method of the lens module includes the following steps. First, the mating receptacle is installed on a printed circuit board of an electronic device by a surface mounting technology. Second, the module body is installed in the mating receptacle to implement electrical interconnection between the module body and the printed circuit board. | 1. A method for assembling a lens module, comprising the steps of: providing a module body and a mating receptacle, wherein the module body includes a lens unit and an image sensing and a processing unit, and wherein the mating receptacle includes a plurality of conductive terminals for receiving an image signal generated from the image sensing and processing unit; mounting and electrically connecting the mating receptacle with a printed circuit board; and connecting the module body with the mating receptacle for transmitting the image signal through the conductive terminals to the printed circuit board. 2. The method as claimed in claim 1, wherein the mating receptacle is mounted on the printed circuit board by a Surface Mounting Technology (SMT). 3. The method as claimed in claim 1, wherein the mating receptacle has a positioning groove for quick positioning the module body. 4. The method as claimed in claim 1, wherein the mating receptacle and the module body are firmly fastened together via a fastening element. 5. The method as claimed in claim 1, wherein the mating receptacle and the module body are clamped together firmly via a clamping element. 6. A lens module for achieving an electrical interconnection with a printed circuit board of an electronic device, comprising: a module body having a lens unit and an image sensing and processing unit, and the image sensing and processing unit for receiving a light through the lens unit to generate an image signal; and a mating receptacle made of an insulating material, the mating receptacle being detachably engaged with the module body and having a plurality of conductive terminals for transmitting the image signal. 7. The lens module as claimed in claim 6, wherein the mating receptacle has a positioning groove for quick positioning the module body. 8. The lens module as claimed in claim 6, wherein the mating receptacle has a dowel pin for quick positioning the module body. 9. The lens module as claimed in claim 6, wherein the mating receptacle has a fastening element for fastening the module body. 10. The lens module as claimed in claim 6, wherein the mating receptacle been electrically connected with the printed circuit board of the electronic device by a Surface Mounting Technology (SMT). 11. The lens module as claimed in claim 6, wherein the conductive terminals of the mating receptacle have outer ends for soldering on corresponding welds of the printed circuit board of the electronic device. 12. The lens module as claimed in claim 6, further comprising a metal shield for covering the module body to prevent and/or reduce potential influence caused by an Electromagnetic Interference (EMI). 13. The lens modules as claimed in claim 12, wherein the metal shield has an opening for providing exterior light beams into the lens unit. 14. The lens modules as claimed in claim 12, wherein the metal shield has a fastening portion for engaging with the module body or the mating receptacle. 15. The lens modules as claimed in claim 12, wherein the metal shield has a grounding terminal to connect with the printed circuit board of the electronic device to provide a grounding function. 16. The lens modules as claimed in claim 12, wherein the metal shield has a metal grid or a plurality of holes to dissipate heat and prevent the Electromagnetic Interference (EMI). | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens module and an assembling method thereof, and more particularly, to a lens module and an assembling method thereof capable of achieving an electrical interconnection with a printed circuit board of an electronic device through a mating receptacle. 2. Description of Prior Art Nowadays, the mass-production of a lens module that is widely applied in an electronic device with a photograph function (such as a mobile phone with a photograph function or a personal digital assistant (PDA) with a photograph function), generally suffers from the disadvantage of a relatively high defect rate. Referring to FIG. 1 and FIG. 2, a conventional lens module 1 comprises a lens unit 11, a base 12, an image sensor 131, a fixing substrate 14 and a flexible printed circuit board (FPCB) 13. The base 12 holds the lens unit 11 and has a top opening for introducing exterior light beams into the image sensor 131 formed on the fixing substrate 14 via the lens unit 11. The image sensor 131 generates an image signal that is transmitted to a printed circuit board of an electronic device (such as a printed circuit board 101 of a camera 100 shown in FIG. 3) by the flexible printed circuit board 13. However, in order to output the image signal, a flexible printed circuit board must be used in the conventional lens module 1, thereby preventing the lens module 1 from being directly mounted on the printed circuit board of an electronic device in an automatic, mass-production manner, and keeping the cost thereof high. Therefore, the present invention provides an improved lens module and an assembling method thereof that can overcome or at least reduce the disadvantages set forth above. SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, a lens module is provided, which is capable of achieving an electrical interconnection with a printed circuit board of an electronic device, comprising a module body and a mating receptacle. The module body has a lens unit and an image sensing and processing unit; the image sensing and processing unit receives light beams from the lens unit and produces an image signal. The mating receptacle is made of insulating material, which is detachably engaged with the module body and has conductive terminals formed therein for transmitting the image signal. In accordance with another aspect of the present invention, an assembling method of a lens module is provided, and comprises the following steps. First, the lens module is divided into a module body and a mating receptacle electrically interconnected with the module body. The module body has a lens unit and an image sensing and processing unit. The mating receptacle has conductive terminals for transmitting an image signal produced from the image sensing and processing unit. Second, the mating receptacle is installed onto a printed circuit board of an electronic device. Finally, the module body is installed in the mating receptacle so as to implement electrical interconnection between the module body and the printed circuit board. The present invention shortens an assembly procedure that involves the module body, reduces the possibility of contamination of and shock to the lens module, and improves the yield rate of the production. BRIEF DESCRIPTION OF THE DRAWINGS Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 is an exploded perspective view of a conventional lens module; FIG. 2 is an assembled perspective view of the conventional lens module; FIG. 3 shows an applying embodiment of the convention lens module, which is applied in a camera; FIG. 4 is an exploded perspective view of a lens module according to the present invention; FIG. 5 is a partial, cross-sectional view of the lens modules of the present invention; FIG. 6 is a bottom view of a module body of the lens module of the present invention; FIG. 7 is an assembled perspective view of the lens module of the present invention; FIG. 8 shows an embodiment of the lens module of the present invention, applied in a camera; FIG. 9 is an exploded perspective view of an embodiment of a lens module according to the present invention; FIG. 10 is an exploded perspective view of another embodiment of a lens module according to the present invention; and FIG. 11 is an exploded perspective view of another embodiment of a lens module according to the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 4 to FIG. 7, a lens module 200 of the present invention includes a module body 2 and a mating receptacle 3. The module body 2 uses a base 22 to receive a lens unit 21, an image sensing and processing unit 23 and a plurality of conductive terminals 231 (as shown in FIG. 6). The mating receptacle 3 is made of a conventional insulating material, which has a positioning groove 31 and a plurality of conductive terminals 33. In assembly, the positioning groove 31 guides the module body 2 to be positioned quickly, thereby finishing an electrical interconnection between inner ends 331 of the terminals 33 and the terminals 231 accurately, and causing outer ends 332 of the terminals 33 to connect electrically to corresponding welds 501 of a printed circuit board 500. More preferably, fastening members 32 are defined on the mating receptacle 3 for fastening the module body 2. In other words, the mating receptacle 3 and the module body 2 are detachably engaged with each other so that the electrical interconnection between the inner ends 331 of the conductive terminals 33 and the conductive terminals 231 becomes more stable and reliable. The installation of the lens module 200 includes the following steps. First, the outer ends 332 of the conductive terminals 33 of the mating receptacle 3 are electrically connected to the printed circuit board 500 via a surface mounting technology. Second, the module body 2 are fastened on or connected to the mating receptacle 3. Consequently, exterior light beams can be introduced into via the lens unit 21, resulting in an image signal being produced from the image sensing and processing unit 23. The image signal is transmitted to the printed circuit board 500 by the terminals 231 and the terminals 33 of the mating receptacle 3. Referring to FIG. 8, in this embodiment according to the present invention, the printed circuit board 500 is an inner printed circuit board of a digital camera 600 or other type of electrical product with a photograph function. The image signal as described above can be stored in a memory unit of the digital camera 600 through the printed circuit board 500. Conversely, the image signal is displayed by, for example a display of the digital camera 600. Referring to FIG. 9, the present invention further comprises a metal shield 4 for covering the lens module 200 so as to decrease electromagnetic interference. The metal shield 4 includes an opening 41 exposing the lens unit 21. More preferably, the metal shield 4 further has a grounding terminal 42 adapted to connect to the printed circuit board 500 for providing a grounding function, thereby decreasing electromagnetic interference. FIG. 10 and FIG. 11 illustrate a lens module 700 according to another embodiment of the present invention, which also has a metal shield 9 for decreasing electromagnetic interference. The lens module 700 also includes a module body 7 and a mating receptacle 8. The module body 7 has a lens unit 71, a base 72 and an image sensing and processing unit 73. The mating receptacle 8 has a positioning groove 81 and fastening elements 82. By guiding of the positioning groove 81, the module body 7 is positioned in a proper place and further fastened by the fastening elements 82. The metal shield 9 has an opening 91 and fastening portions 92. Exterior light beams pass through the opening 91 and enter into the lens unit 71. The metal shield 9 is fastened on the mating receptacle 8 by the fastening portions 92. Thus, the lens module 700 can be protected from electromagnetic interference with the metal shield 9. Of course, the present invention has other embodiments. For example, a dowel pin (not shown) or a position post (not shown) that is generally used in a common mechanism design can be used instead of the positioning groove 31, 81 of the present invention. The fastening elements 32, 82 also can be replaced with adhesive, conventional clamping elements or other elements that can provide a fastening function. The metal shields 4, 9 can further comprise metal grids or holes (not shown) so as to achieve double functions of dispersing heat and blocking an electromagnetic interference. As mentioned above, the assembling method and the structure of the lens module in accordance with the present invention have the following advantages. 1. The present invention leaves out the FPCB 13 that is necessary in the prior art, thereby saving material cost. 2. Before the lens unit 2 (7) is inserted into the mating receptacle 3 (8) of the lens module 200 (700), the mating receptacles 3, 8 are easily and automatically mounted on the printed circuit board 500 of an electronic device by conventional surface mounting technology. Thus, the chance that the lens module 200 (700) is stained with dirt or loses its precision because of shaking is decreased. Compares with the conventional structure, this design is much more suitable for mass production and much more easily improves yield rate of products. 3. The present invention can decrease electromagnetic interference to the lens module 200 (700) with the metal shield 4 (9). The invention has been explained in relation to some of its preferred embodiments. It is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a lens module and an assembling method thereof, and more particularly, to a lens module and an assembling method thereof capable of achieving an electrical interconnection with a printed circuit board of an electronic device through a mating receptacle. 2. Description of Prior Art Nowadays, the mass-production of a lens module that is widely applied in an electronic device with a photograph function (such as a mobile phone with a photograph function or a personal digital assistant (PDA) with a photograph function), generally suffers from the disadvantage of a relatively high defect rate. Referring to FIG. 1 and FIG. 2 , a conventional lens module 1 comprises a lens unit 11 , a base 12 , an image sensor 131 , a fixing substrate 14 and a flexible printed circuit board (FPCB) 13 . The base 12 holds the lens unit 11 and has a top opening for introducing exterior light beams into the image sensor 131 formed on the fixing substrate 14 via the lens unit 11 . The image sensor 131 generates an image signal that is transmitted to a printed circuit board of an electronic device (such as a printed circuit board 101 of a camera 100 shown in FIG. 3 ) by the flexible printed circuit board 13 . However, in order to output the image signal, a flexible printed circuit board must be used in the conventional lens module 1 , thereby preventing the lens module 1 from being directly mounted on the printed circuit board of an electronic device in an automatic, mass-production manner, and keeping the cost thereof high. Therefore, the present invention provides an improved lens module and an assembling method thereof that can overcome or at least reduce the disadvantages set forth above. | <SOH> SUMMARY OF THE INVENTION <EOH>In accordance with one aspect of the present invention, a lens module is provided, which is capable of achieving an electrical interconnection with a printed circuit board of an electronic device, comprising a module body and a mating receptacle. The module body has a lens unit and an image sensing and processing unit; the image sensing and processing unit receives light beams from the lens unit and produces an image signal. The mating receptacle is made of insulating material, which is detachably engaged with the module body and has conductive terminals formed therein for transmitting the image signal. In accordance with another aspect of the present invention, an assembling method of a lens module is provided, and comprises the following steps. First, the lens module is divided into a module body and a mating receptacle electrically interconnected with the module body. The module body has a lens unit and an image sensing and processing unit. The mating receptacle has conductive terminals for transmitting an image signal produced from the image sensing and processing unit. Second, the mating receptacle is installed onto a printed circuit board of an electronic device. Finally, the module body is installed in the mating receptacle so as to implement electrical interconnection between the module body and the printed circuit board. The present invention shortens an assembly procedure that involves the module body, reduces the possibility of contamination of and shock to the lens module, and improves the yield rate of the production. | 20040714 | 20051220 | 20051027 | 57770.0 | 0 | BEN, LOHA | LENS MODULE AND ASSEMBLING METHOD THEREOF | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,234 | ACCEPTED | Semiconductor device and method for manufacturing the same | The present invention provides a method for manufacturing a semiconductor device, by which a transistor including an active layer, a gate insulating film in contact with the active layer, and a gate electrode overlapping the active layer with the gate insulating film therebetween is provided; an impurity is added to a part of a first region overlapped with the gate electrode with the gate insulating film therebetween in the active layer and a second region but the first region in the active layer by adding the impurity to the active layer from one oblique direction; and the second region is situated in the one direction relative to the first region. | 1. A semiconductor device comprising: a plurality of thin film transistors formed over a substrate, each of plurality of thin film transistors comprising a semiconductor film and a gate electrode with a gate insulating film interposed therebetween, wherein the semiconductor film comprises a channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the gate electrode, and wherein directions from the second impurity region to the channel formation region in the plurality of thin film transistors are consistent with each other. 2. A semiconductor device according to claim 1, wherein the plurality of thin film transistors have a same conductivity type with each other. 3. A semiconductor device according to claim 1, wherein the first impurity region is at least one of source region and drain region. 4. A semiconductor device according to claim 1, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 5. A semiconductor device comprising: a plurality of first thin film transistors and a plurality of second thin film transistor, each formed over a same substrate, wherein each of the plurality of first thin film transistors comprises a first semiconductor film and a first gate electrode with a first gate insulating film interposed therebetween, wherein the first semiconductor film comprises a first channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the first gate electrode, and wherein directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors are consistent with each other; and wherein each of the plurality of second thin film transistors comprises a second semiconductor film and a second gate electrode with a second gate insulating film interposed therebetween, wherein the second semiconductor film comprises a second channel formation region and a third impurity region in contact with the second channel formation region along the directions. 6. A semiconductor device according to claim 5, wherein the plurality of first thin film transistors have a same conductivity type with each other. 7. A semiconductor device according to claim 5, wherein the plurality of second thin film transistors have a same conductivity type with each other. 8. A semiconductor device according to claim 5, wherein the first impurity region and the third impurity region are at least one of source region and drain region. 9. A semiconductor device according to claim 5, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 10. A semiconductor device comprising: a plurality of first thin film transistors and a plurality of second thin film transistor, each formed over a same substrate, wherein each of the plurality of first thin film transistors comprises a first semiconductor film and a first gate electrode with a first gate insulating film interposed therebetween, wherein the first semiconductor film comprises a first channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the first gate electrode, and wherein directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors are consistent with each other; and wherein each of the plurality of second thin film transistors comprises a second semiconductor film and a second gate electrode with a second gate insulating film interposed therebetween, wherein the second semiconductor film comprises a second channel formation region and a third impurity region with a fourth impurity region interposed therebetween, wherein the fourth impurity region has a lower impurity concentration than that of the third impurity region, and is not overlapped with the second gate electrode, and wherein the fourth impurity region is in contact with the second channel formation region along the directions. 11. A semiconductor device according to claim 10, wherein the plurality of first thin film transistors have a same conductivity type with each other. 12. A semiconductor device according to claim 10, wherein the plurality of second thin film transistors have a same conductivity type with each other. 13. A semiconductor device according to claim 10, wherein the first impurity region and the third impurity region are at least one of source region and drain region. 14. A semiconductor device according to claim 10, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 15. A semiconductor device comprising: a plurality of first thin film transistors and a plurality of second thin film transistor, each formed over a same substrate, wherein each of the plurality of first thin film transistors comprises a first semiconductor film and a first gate electrode with a first gate insulating film interposed therebetween, wherein the first semiconductor film comprises a first channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the first gate electrode, and wherein directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors are consistent with each other; and wherein each of the plurality of second thin film transistors comprises a second semiconductor film and a second gate electrode with a second gate insulating film interposed therebetween, wherein the second semiconductor film comprises a second channel formation region and a third impurity region with an offset region interposed therebetween, wherein directions from the offset region to the second channel formation region in the plurality of second thin film transistors are consistent with each other, and are opposite to the directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors. 16. A semiconductor device according to claim 15, wherein the plurality of first thin film transistors have a same conductivity type with each other. 17. A semiconductor device according to claim 15, wherein the plurality of second thin film transistors have a same conductivity type with each other. 18. A semiconductor device according to claim 15, wherein the first impurity region and the third impurity region are at least one of source region and drain region. 19. A semiconductor device according to claim 15, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 20. A semiconductor device comprising: a thin film transistor formed over a substrate, the thin film transistor comprising a semiconductor film and a gate electrode with a gate insulating film interposed therebetween, wherein the semiconductor film comprises a channel formation region, a pair of first impurity regions and a pair of second impurity regions wherein the pair of second impurity regions have a lower impurity concentration than those of the pair of first impurity regions, and are overlapped with the gate electrode, nad wherein a direction from one of the pair of second impurity regions to the channel formation region is in consistent with a direction from the other one of the pair of second impurity regions to the channel formation region. 21. A semiconductor device according to claim 20, wherein the first impurity region is at least one of source region and drain region. 22. A semiconductor device according to claim 20, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 23. A semiconductor device comprising: a display element formed between a first substrate and a second substrate; an integrated circuit formed over a third substrate, the integrated circuit controlling an operation of the display element, and comprising a plurality of thin film transistors, wherein each of plurality of thin film transistors comprises a semiconductor film and a gate electrode with a gate insulating film interposed therebetween, wherein the semiconductor film comprises a channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the gate electrode, and wherein directions from the second impurity region to the channel formation region in the plurality of thin film transistors are consistent with each other. 24. A semiconductor device according to claim 23, wherein the plurality of thin film transistors have a same conductivity type with each other. 25. A semiconductor device according to claim 23, wherein the first impurity region is at least one of source region and drain region. 26. A semiconductor device according to claim 23, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 27. A semiconductor device comprising: a display element formed between a first substrate and a second substrate; an integrated circuit formed over a third substrate, the integrated circuit controlling an operation of the display element, and comprising a plurality of first thin film transistors and a plurality of second thin film transistors, wherein each of the plurality of first thin film transistors comprises a first semiconductor film and a first gate electrode with a first gate insulating film interposed therebetween, wherein the first semiconductor film comprises a first channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the first gate electrode, and wherein directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors are consistent with each other; and wherein each of the plurality of second thin film transistors comprises a second semiconductor film and a second gate electrode with a second gate insulating film interposed therebetween, wherein the second semiconductor film comprises a second channel formation region and a third impurity region in contact with the second channel formation region along the directions. 28. A semiconductor device according to claim 27, wherein the plurality of first thin film transistors have a same conductivity type with each other. 29. A semiconductor device according to claim 27, wherein the plurality of second thin film transistors have a same conductivity type with each other. 30. A semiconductor device according to claim 27, wherein the first impurity region and the third impurity region are at least one of source region and drain region. 31. A semiconductor device according to claim 27, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 32. A semiconductor device comprising: a display element formed between a first substrate and a second substrate; an integrated circuit formed over a third substrate, the integrated circuit controlling an operation of the display element, and comprising a plurality of first thin film transistors and a plurality of second thin film transistors, wherein each of the plurality of first thin film transistors comprises a first semiconductor film and a first gate electrode with a first gate insulating film interposed therebetween, wherein the first semiconductor film comprises a first channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the first gate electrode, and wherein directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors are consistent with each other; and wherein each of the plurality of second thin film transistors comprises a second semiconductor film and a second gate electrode with a second gate insulating film interposed therebetween, wherein the second semiconductor film comprises a second channel formation region and a third impurity region with a fourth impurity region interposed therebetween, wherein the fourth impurity region has a lower impurity concentration than that of the third impurity region, and is not overlapped with the second gate electrode, and wherein the fourth impurity region is in contact with the second channel formation region along the directions. 33. A semiconductor device according to claim 32, wherein the plurality of first thin film transistors have a same conductivity type with each other. 34. A semiconductor device according to claim 32, wherein the plurality of second thin film transistors have a same conductivity type with each other. 35. A semiconductor device according to claim 32, wherein the first impurity region and the third impurity region are at least one of source region and drain region. 36. A semiconductor device according to claim 32, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 37. A semiconductor device comprising: a display element formed between a first substrate and a second substrate; an integrated circuit formed over a third substrate, the integrated circuit controlling an operation of the display element, and comprising a plurality of first thin film transistors and a plurality of second thin film transistors, wherein each of the plurality of first thin film transistors comprises a first semiconductor film and a first gate electrode with a first gate insulating film interposed therebetween, wherein the first semiconductor film comprises a first channel formation region and a first impurity region with a second impurity region interposed therebetween, wherein the second impurity region has a lower impurity concentration than that of the first impurity region, and is overlapped with the first gate electrode, and wherein directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors are consistent with each other; and wherein each of the plurality of second thin film transistors comprises a second semiconductor film and a second gate electrode with a second gate insulating film interposed therebetween, wherein the second semiconductor film comprises a second channel formation region and a third impurity region with an offset region interposed therebetween, wherein directions from the offset region to the second channel formation region in the plurality of second thin film transistors are consistent with each other, and are opposite to the directions from the second impurity region to the first channel formation region in the plurality of first thin film transistors. 38. A semiconductor device according to claim 37, wherein the plurality of first thin film transistors have a same conductivity type with each other. 39. A semiconductor device according to claim 37, wherein the plurality of second thin film transistors have a same conductivity type with each other. 40. A semiconductor device according to claim 37, wherein the first impurity region and the third impurity region are at least one of source region and drain region. 41. A semiconductor device according to claim 37, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 42. A semiconductor device comprising: a display element formed between a first substrate and a second substrate; an integrated circuit formed over a third substrate, the integrated circuit controlling an operation of the display element, and comprising a thin film transistor, wherein the thin film transistor comprises a semiconductor film and a gate electrode with a gate insulating film interposed therebetween, wherein the semiconductor film comprises a channel formation region, a pair of first impurity regions and a pair of second impurity regions, wherein the pair of second impurity regions have a lower impurity concentration than those of the pair of first impurity regions, and are overlapped with the gate electrode, nad wherein a direction from one of the pair of second impurity regions to the channel formation region is in consistent with a direction from the other one of the pair of second impurity regions to the channel formation region. 43. A semiconductor device according to claim 42, wherein the first impurity region is at least one of source region and drain region. 44. A semiconductor device according to claim 42, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 45. A method for manufacturing a semiconductor device comprising: forming a semiconductor film over a substrate; forming a gate insulating film on the semiconductor film; forming a gate electrode on the gate insulating film; doping an impurity element into a portion of the semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction. 46. A method for manufacturing a semiconductor device according to claim 45, wherein the first region comprises a channel formation region and an LDD region. 47. A method for manufacturing a semiconductor device according to claim 45, wherein the second region comprises at least one of source region and drain region. 48. A method for manufacturing a semiconductor device according to claim 45, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 49. A method for manufacturing a semiconductor device comprising: forming a first semiconductor film and a second semiconductor film over a substrate; forming a first gate electrode over the first semiconductor film and a second gate electrode over the second semiconductor film; doping an impurity element into a portion of the first semiconductor film and a portion of the second semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the first semiconductor film, and whereby a third region and a fourth region are formed in the second semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction, and wherein the third region is in contact with the fourth region along the one direction. 50. A method for manufacturing a semiconductor device according to claim 49, wherein the first region comprises a channel formation region and an LDD region. 51. A method for manufacturing a semiconductor device according to claim 49, wherein the second region comprises at least one of source region and drain region. 52. A method for manufacturing a semiconductor device according to claim 49, wherein the third region comprises a channel formation region. 53. A method for manufacturing a semiconductor device according to claim 49, wherein the fourth region comprises at least one of source region and drain region. 54. A method for manufacturing a semiconductor device according to claim 49, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 55. A method for manufacturing a semiconductor device comprising: forming a first semiconductor film and a second semiconductor film over a substrate; forming a first gate electrode over the first semiconductor film and a second gate electrode over the second semiconductor film; forming a resist mask so as to cover the second gate electrode; doping an impurity element into a portion of the first semiconductor film and a portion of the second semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the first semiconductor film, and whereby a third region, a fourth region and a fifth region are formed in the second semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction, wherein the third region is in contact with the fourth region along the one direction, and wherein the fourth region is in contact with the fifth region along the one direction. 56. A method for manufacturing a semiconductor device according to claim 55, wherein the first region comprises a channel formation region and an LDD region. 57. A method for manufacturing a semiconductor device according to claim 55, wherein the second region comprises at least one of source region and drain region. 58. A method for manufacturing a semiconductor device according to claim 55, wherein the third region comprises a channel formation region. 59. A method for manufacturing a semiconductor device according to claim 55, wherein the fourth region comprises an LDD region which is not overlapped with the second gate electrode. 60. A method for manufacturing a semiconductor device according to claim 55, wherein the fifth region is at least one of source region and drain region. 61. A method for manufacturing a semiconductor device according to claim 55, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 62. A method for manufacturing a semiconductor device comprising: forming a first semiconductor film and a second semiconductor film over a substrate; forming a first gate electrode over the first semiconductor film and a second gate electrode over the second semiconductor film; doping an impurity element into a portion of the first semiconductor film and a portion of the second semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the first semiconductor film, and whereby a third region and a fourth region are formed in the second semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction, and wherein a direction from the fourth region to the third region is opposite to the one direction. 63. A method for manufacturing a semiconductor device according to claim 62, wherein the first region comprises a channel formation region and an LDD region. 64. A method for manufacturing a semiconductor device according to claim 62, wherein the second region comprises at least one of source region and drain region. 65. A method for manufacturing a semiconductor device according to claim 62, wherein the third region comprises a channel formation region and an offset region. 66. A method for manufacturing a semiconductor device according to claim 62, wherein the fourth region comprises at least one of source region and drain region. 67. A method for manufacturing a semiconductor device according to claim 62, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 68. A method for manufacturing a semiconductor device comprising: forming a semiconductor film over a first substrate; forming a gate insulating film on the semiconductor film; forming a gate electrode on the gate insulating film; doping an impurity element into a portion of the semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction; forming a plurality of integrated circuits by using at least the semiconductor film; dividing the first substrate into a plurality of second substrates, wherein at least one of the plurality of second substrates has at least one of the plurality of integrated circuits; mounting the at least one of the plurality of second substrates over a third substrate, wherein a semiconductor element or a display element is formed over the third substrate; and electrically connecting the at least one of the plurality of integrated circuits with the semiconductor element or the display element. 69. A method for manufacturing a semiconductor device according to claim 68, wherein the first region comprises a channel formation region and an LDD region. 70. A method for manufacturing a semiconductor device according to claim 68, wherein the second region comprises at least one of source region and drain region. 71. A method for manufacturing a semiconductor device according to claim 68, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 72. A method for manufacturing a semiconductor device comprising: forming a first semiconductor film and a second semiconductor film over a substrate; forming a first gate electrode over the first semiconductor film and a second gate electrode over the second semiconductor film; doping an impurity element into a portion of the first semiconductor film and a portion of the second semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the first semiconductor film, and whereby a third region and a fourth region are formed in the second semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction, and wherein the third region is in contact with the fourth region along the one direction; forming a plurality of integrated circuits by using at least the semiconductor film; dividing the first substrate into a plurality of second substrates, wherein at least one of the plurality of second substrates has at least one of the plurality of integrated circuits; mounting the at least one of the plurality of second substrates over a third substrate, wherein a semiconductor element or a display element is formed over the third substrate; and electrically connecting the at least one of the plurality of integrated circuits with the semiconductor element or the display element. 73. A method for manufacturing a semiconductor device according to claim 72, wherein the first region comprises a channel formation region and an LDD region. 74. A method for manufacturing a semiconductor device according to claim 72, wherein the second region comprises at least one of source region and drain region. 75. A method for manufacturing a semiconductor device according to claim 72, wherein the third region comprises a channel formation region. 76. A method for manufacturing a semiconductor device according to claim 72, wherein the fourth region comprises at least one of source region and drain region. 77. A method for manufacturing a semiconductor device according to claim 72, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 78. A method for manufacturing a semiconductor device comprising: forming a first semiconductor film and a second semiconductor film over a substrate; forming a first gate electrode over the first semiconductor film and a second gate electrode over the second semiconductor film; forming a resist mask so as to cover the second gate electrode; doping an impurity element into a portion of the first semiconductor film and a portion of the second semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the first semiconductor film, and whereby a third region, a fourth region and a fifth region are formed in the second semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction, wherein the third region is in contact with the fourth region along the one direction, and wherein the fourth region is in contact with the fifth region along the one direction; forming a plurality of integrated circuits by using at least the semiconductor film; dividing the first substrate into a plurality of second substrates, wherein at least one of the plurality of second substrates has at least one of the plurality of integrated circuits; mounting the at least one of the plurality of second substrates over a third substrate, wherein a semiconductor element or a display element is formed over the third substrate; and electrically connecting the at least one of the plurality of integrated circuits with the semiconductor element or the display element. 79. A method for manufacturing a semiconductor device according to claim 78, wherein the first region comprises a channel formation region and an LDD region. 80. A method for manufacturing a semiconductor device according to claim 78, wherein the second region comprises at least one of source region and drain region. 81. A method for manufacturing a semiconductor device according to claim 78, wherein the third region comprises a channel formation region. 82. A method for manufacturing a semiconductor device according to claim 78, wherein the fourth region comprises an LDD region which is not overlapped with the second gate electrode. 83. A method for manufacturing a semiconductor device according to claim 78, wherein the fifth region is at least one of source region and drain region. 84. A method for manufacturing a semiconductor device according to claim 78, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. 85. A method for manufacturing a semiconductor device comprising: forming a first semiconductor film and a second semiconductor film over a substrate; forming a first gate electrode over the first semiconductor film and a second gate electrode over the second semiconductor film; doping an impurity element into a portion of the first semiconductor film and a portion of the second semiconductor film from oblique one direction with respect to a surface of the substrate, whereby a first region and a second region are formed in the first semiconductor film, and whereby a third region and a fourth region are formed in the second semiconductor film, wherein a direction from the second region to the first region is in consistent with the one direction, and wherein a direction from the fourth region to the third region is opposite to the one direction; forming a plurality of integrated circuits by using at least the semiconductor film; dividing the first substrate into a plurality of second substrates, wherein at least one of the plurality of second substrates has at least one of the plurality of integrated circuits; mounting the at least one of the plurality of second substrates over a third substrate, wherein a semiconductor element or a display element is formed over the third substrate; and electrically connecting the at least one of the plurality of integrated circuits with the semiconductor element or the display element. 86. A method for manufacturing a semiconductor device according to claim 85, wherein the first region comprises a channel formation region and an LDD region. 87. A method for manufacturing a semiconductor device according to claim 85, wherein the second region comprises at least one of source region and drain region. 88. A method for manufacturing a semiconductor device according to claim 85, wherein the third region comprises a channel formation region and an offset region. 89. A method for manufacturing a semiconductor device according to claim 85, wherein the fourth region comprises at least one of source region and drain region. 90. A method for manufacturing a semiconductor device according to claim 85, wherein the semiconductor device is at least one selected from the group consisting of a portable digital assistant, a cellular phone, an electronic card, an electronic book, a personal computer, and a display device. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a transistor, specifically a thin film transistor, having an LDD region, and further relates to a semiconductor device using the manufacturing method. 2. Related Art A semiconductor display device formed by using an inexpensive glass substrate cannot easily be miniaturized since a peripheral area (frame area) of a pixel portion required for mounting occupies more area in a substrate as resolution becomes higher. Thus, it is considered that there is a limitation on a method for mounting an integrated circuit formed by using a single crystalline silicon wafer on a glass substrate. Therefore, a technique for integrally forming an integrated circuit including a driver circuit over a glass substrate provided with a pixel portion, that is referred to as System On Panel, is now focused on. However, an integrated circuit formed over a glass substrate has lower degree of integration than that of an integrated circuit formed over a single crystalline silicon wafer. Therefore, it is an important object to miniaturize a semiconductor element on practical application. According to miniaturization of a semiconductor element, an integrated circuit formed over a glass substrate can highly be integrated, thereby promoting miniaturization, weight reduction, further, low power consumption, and speedup of a semiconductor display device. In addition, according to miniaturization of a semiconductor element as well as an integrated circuit, high definition can be realized also in a pixel portion. A semiconductor display device provided with a thin film transistor (TFT) using an amorphous semiconductor film in a pixel portion has the advantage of having high productivity and low cost. However, the TFT using an amorphous semiconductor film has the disadvantage of having low mobility. Therefore, it is considered that a thin film transistor using an amorphous semiconductor film is unsuitable for a driver circuit that required high-speed operation such as a scanning line driver circuit for selecting a pixel or a signal line driver circuit for supplying a video signal to the selected pixel. Thus, a mode of manufacturing an IC chip in which a driver circuit is included by using a single crystalline silicon wafer and of mounting the IC chip on the periphery of a pixel portion by TAB (Tape Automated bonding) or COG (Chip on Glass) is generally adopted. However, a unit cost of a silicon wafer is higher than that of a glass substrate, and a silicon wafer is not suitable for providing an inexpensive IC chip. The advantage of a low cost that is a characteristic of a semiconductor display device using an amorphous semiconductor film cannot fully be utilized. The sizes of silicon wafers that are comparatively a lot on the market are approximately not more than 12 inches in diameter. Although more than 12 inches sized silicon wafers are also on the market, a cost per unit area further increases as its size increases. Consequently, costs have to be sacrificed in order to increase throughput by increasing the number of IC chips obtained from one substrate. Thus, a technique of forming a driver circuit over a glass substrate, dividing into strips, and mounting on a substrate over which a pixel portion is formed is disclosed in the following references (Reference 1: Japanese Patent Application Laid-Open No. 7-014880, and Reference 2: Japanese Patent Application Laid-Open No. 11-160734). As disclosed in References 1 and 2, an incidence rate of a defect in a contact portion of a terminal, caused by a difference of a thermal expansion coefficient can be decreased by using a substrate made of the same material as a substrate over which a pixel portion is formed (hereinafter, referred to as an element substrate), forming a driver circuit, and mounting on the element substrate. Accordingly, a yield can be increased. In addition, a cost of a semiconductor display device as a whole can be reduced by forming a driver circuit over a glass substrate. Meanwhile, a semiconductor display device cannot easily be miniaturized since a peripheral area (frame area) of a pixel portion required for mounting occupies more area in a substrate as resolution of a pixel portion becomes higher. Therefore, an IC chip mounted on a substrate over which a pixel portion is formed is preferably smaller. However, an integrated circuit formed over a glass substrate has lower degree of integration than that of an integrated circuit formed over a single crystalline silicon wafer. Therefore, on promoting miniaturization of a semiconductor display device and high integration of an integrated circuit, it is an important object to miniaturize a semiconductor element formed over a glass substrate. When an integrated circuit formed over a glass substrate can highly be integrated according to miniaturization of a semiconductor element, miniaturization, weight reduction, further, low power consumption, and speedup of a semiconductor display device can be advanced. However, miniaturization of a TFT that is one of semiconductor elements involves a problem of decline in reliability due to a hot carrier effect. Therefore, an LDD (Lightly Doped Drain) structure is adopted as a means of controlling a hot carrier effect. The LDD structure is a structure in which an LDD region having a lower impurity concentration than that of a source/drain region is provided between the source/drain region and a channel formation region. Particularly, it is known that in the case of having a structure in which an LDD region is overlapped with a gate electrode with a gate insulating film therebetween (GOLD structure, Gate Overlapped Lightly Doped Drain structure), a hot carrier effect can efficiently be prevented by relaxation of a high electric field in the vicinity of a drain and reliability can be improved. In this specification, a region in which an LDD region is overlapped with a gate electrode with a gate insulating film therebetween is referred to as an Lov region and a region in which an LDD region is not overlapped with a gate electrode is referred to as an Loff region. It is disclosed in the following reference that deterioration of a transistor can be prevented by employing a GOLD structure (Reference 3: Japanese Patent Application Laid-Open No. 8-153875). A TFT having an Loff region tends to be able to reduce more off current than a TFT having an Lov region. Therefore, a TFT having an Loff region is suitably used for a switching element of a pixel in which reduction of an off current is regarded as more important than high-speed drive. Meanwhile, a TFT having an Lov region can be driven at higher speed than a TFT having an Loff region. Specifically, switching can be performed at higher speed. A TFT having an Lov region is suitably used for a driver circuit since operating frequency is higher than that of a pixel portion and high-speed drive is regarded as more important than reduction of an off current. It is preferable that a TFT having an Loff region and a TFT having an Lov region are appropriately used according to characteristics required for a circuit element. Several methods have been proposed for manufacturing a TFT having an Lov region, and one of them is to obliquely implant ions using a gate electrode as a mask. According to the above method, a dopant (impurity) can be added by an ion implantation method to a region overlapped with a gate electrode with a gate insulating film therebetween, without using a resist mask and with the number of steps reduced. However, in order to form an Lov region on both a source region side and a drain region side, it is necessary to perform ion implantation twice from a different implantation direction. This can be a factor of preventing a throughput in a step of ion implantation from improving. In addition, there is a method (tilt rotation) for obliquely and uniformly implanting ions by rotating a substrate; however, according to this method, rotation of a substrate need to precisely be controlled and a large-scale apparatus for performing ion implantation is required. Particularly, the method is not suitable for a large substrate, and becomes a factor in preventing throughput from improving. In addition, according to the above method, there is a problem that a TFT having an Lov region and a TFT having an Loff region cannot separately be formed over one substrate. According to the above method, a TFT having an Lov region and a TFT having an Loff region cannot separately be formed over one substrate in the case of integrating a pixel portion and a driver circuit by System On Panel. In addition, such a TFT without an LDD region that a source region and a drain region are in contact with a channel formation region and a TFT having an Lov region cannot separately be formed over one substrate. A TFT having an Lov region and a TFT having an Loff region can separately be formed over one substrate by separately implanting a dopant using a resist mask. However, the number of resist masks and steps cannot be reduced, which becomes a factor of increasing a manufacturing cost. When a transistor having an offset gate structure, a transistor in which a source region and a drain region are in contact with a channel formation region, and the like as well as a TFT having an Loff region are intended to separately be formed over one substrate, the number of resist masks and steps cannot be reduced, which becomes a factor of increasing a manufacturing cost. SUMMARY OF THE INVENTION In view of the above problems, the present invention relates to a method for manufacturing a semiconductor device in which a transistor having an Lov region can separately be formed over a substrate provided with a transistor having an Loff region, a transistor having an offset gate structure, and a transistor in which a source region and a drain region are in contact with a channel formation region without providing a resist mask for forming an Lov region and throughput in a step of ion implantation can be improved. Further, the present invention relates to a semiconductor device that can reduce a cost per panel. Furthermore, the present invention relates to a semiconductor device which can reduce a cost per panel, using a chip in which an integrated circuit is formed of a thin semiconductor film (hereinafter, referred to as a thin film chip). The inventors of the present invention think that it is better to change a position of an Lov region provided in an active layer of a transistor according to a dopant implantation direction than according to change the dopant implantation direction to a position of an Lov region. In other words, ion implantation is regarded as a fixed implantation in which an implantation direction is set to one direction, and a positional relationship among an Lov region, a channel formation region, and a gate electrode functioning as a mask in ion implantation is determined according to the implantation direction. Note that an implantation direction in this specification means a direction that a dopant is implanted from an ion source. Specifically, an implantation direction is set to such one direction that a dopant obliquely intersects with a surface of an active layer, and an edge portion of a gate electrode overlapping an active layer is directed to the implantation direction side. Namely, a gate electrode and an active layer are disposed so that an exposed region of the active layer but a region overlapped with the gate electrode is situated closer to an implantation direction side than the region overlapped with the gate electrode. According to the above structure, an Lov region can be formed on both a source region side and a drain region side by ion implantation from one implantation direction. Therefore, in all transistors having the same conductivity and having an Lov region, the Lov region is disposed closer to a dopant implantation direction side than a channel formation region. In the case of performing ion implantation to form an Lov region, in a transistor having an Loff region, a positional relationship among an active layer, a gate electrode, and an Loff region is determined according to an implantation direction so that an impurity is added only to a region serving as a source region and a drain region. Specifically, a region serving as an Loff region and a channel formation region is covered with a resist mask, and a region overlapped with the resist mask and an exposed region of the active layer but the region are disposed to be in contact with each other along the implantation direction. In other words, an edge portion of the resist mask overlapping the active layer is disposed to be in contact with each other along the implantation direction. According to the above structure, a transistor having an Lov region and a transistor having an Loff region can separately be formed over one substrate. In the case of performing ion implantation to form an Lov region, in a transistor without an LDD region, in which a source region and a drain region are in contact with a channel formation region, a positional relationship among an active layer, a gate electrode, and an LDD region is determined according to an implantation direction so that an impurity is added only to a region serving as a source region and a drain region. Specifically, a region overlapped with the gate electrode and an exposed region of the active layer but the region are disposed to be in contact with each other along the implantation direction. In other words, an edge portion of the gate electrode overlapping the active layer is disposed to be along the implantation direction. According to the above structure, a transistor having an Lov region and a transistor in which a source region and a drain region are in contact with a channel formation region can separately be formed over one substrate. In the case of performing ion implantation to form an Lov region, in a transistor having an offset region, a positional relationship among an active layer, a gate electrode, and an offset region is determined according to an implantation direction so that an impurity is added only to a region serving as a source region and a drain region and the offset region is formed. Specifically, the gate electrode and the active layer are disposed so that an exposed region of the active layer is disposed on an opposite side from an implantation direction with respect to the gate electrode. In other words, an edge portion of the gate electrode overlapping the active layer is disposed on an opposite side of the implantation direction. According to the above structure, a transistor having an Lov region and a transistor having an offset region can separately be formed over one substrate. In addition to the above structure, a continuous wave laser may be used for crystallization of a semiconductor film. A semiconductor film crystallized by using only a pulsed laser beam is formed of a cluster of a plurality of crystal grains, in which the position and the size thereof are at random. Compared to the inside of crystal grains, thousands of recombination centers or trapping centers due to an amorphous structure or a crystal defect exist at the interfaces of crystal grains (crystal grain boundary). There is a problem that the potential of a crystal grain boundary is increased when carriers are trapped in the trapping centers, and is resulted in a barrier against carriers, so that the current transporting characteristics of carriers decrease. On the other hand, in the case of a continuous wave laser beam, a cluster of crystal grains made of single crystals elongating along a scanning direction can be formed by irradiating a semiconductor film while scanning the semiconductor film with an irradiation region (beam spot) of a laser beam in one direction to continuously grow crystals in the scanning direction. Therefore, mobility of a TFT used for a thin film chip can be improved by crystallizing a semiconductor film using a continuous wave laser. A semiconductor device included in the category of the present invention includes all kinds of semiconductor devices using a transistor, such as a microprocessor, an image processing circuit, and a semiconductor display device. In addition, a thin film chip itself is included in the category of the semiconductor device of the present invention. The semiconductor display device includes a liquid crystal display device, a light emitting device having a light emitting element in each pixel, typified by an organic light-emitting element (OLED), a DMD (Digital Micromirror Device), a PDP (Plasma Display Panel), an FED (Field Emission Display), and other display devices having a circuit element using a semiconductor film in a driver circuit in its category. A transistor in which an Lov region can be formed by using a manufacturing method of the present invention is not limited to a TFT using polycrystalline silicon, microcrystalline silicon (semi-amorphous silicon (SAS)), or amorphous silicon. The transistor may be a transistor formed by using single crystalline silicon, and it may be a transistor using SOI. Alternatively, it may be a transistor using an organic semiconductor, and it may be a transistor using a carbon nanotube. In addition, a transistor used for a semiconductor device of the present invention may have a single gate structure, a double gate structure, or a multi gate structure having three or more gate electrodes. According to the above structures of the present invention, a transistor having an Lov region can separately be formed over a substrate provided with a transistor having an Loff region, a transistor in which a source region and a drain region are in contact with a channel formation region, a transistor having an offset region, and the like without providing a resist mask for forming an Lov region. Consequently, the number of resist masks and steps can be reduced, and a manufacturing cost can be reduced. In addition, throughput in a step of ion implantation can be improved. In the present invention, a semiconductor device may be formed by mounting an integrated circuit using the above manufacturing method as a thin film chip on a substrate provided with a pixel portion or other integrated circuits. In addition to the above manufacturing method, the present invention includes the above thin film chip using the above manufacturing method and a semiconductor device on which the thin film chip is mounted in its category. Since a cost per chip of a thin film chip of the present invention can be reduced, a cost of a semiconductor device itself having the thin film chip can also be reduced. These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description along with the accompanied drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: FIGS. 1A and 1B show a method for manufacturing a TFT having an Lov region; FIGS. 2A to 2D show a method for manufacturing a TFT in which a source region and a drain region are in contact with a channel formation region; FIGS. 3A to 3C show crystallization of a semiconductor film by a laser beam, doping, and dicing; FIGS. 4A to 4E show layouts of each transistor in a thin film chip in which a TFT having an Loff region and a TFT having an Lov region are formed; FIGS. 5A and 5B show a method for manufacturing a TFT having an offset region; FIGS. 6A to 6E show layouts of each transistor in a panel in which a TFT having an Loff region and a TFT having an Lov region are formed; FIGS. 7A and 7B are external views of a semiconductor display device on which a thin film chip is mounted; FIGS. 8A to 8D are top views of a TFT having an Lov region; FIGS. 9A to 9C show a method for mounting a thin film chip; FIGS. 10A to 10D show a method for manufacturing a semiconductor device of the present invention; FIGS. 11A to 11C show a method for manufacturing a semiconductor device of the present invention; FIGS. 12A to 12C show a method for manufacturing a semiconductor device of the present invention; FIGS. 13A and 13B show a relationship between an incidence angle of a dopant, and a width of an Lov region and an impurity concentration; FIGS. 14A and 14B are block diagrams showing a structure of a semiconductor display device; FIGS. 15A and 15B are a top view and a cross-sectional view of a light emitting device corresponding to one mode of a semiconductor device of the present invention; FIGS. 16A and 16B are a top view and a cross-sectional view of a light emitting device corresponding to one mode of a semiconductor device of the present invention; FIGS. 17A to 17D show distribution of energy density of a beam spot; FIGS. 18A to 18D show an optical system used for irradiation of a continuous wave laser beam; FIG. 19 is a block diagram of a cellular phone which is one of electronic devices; and FIGS. 20A to 20F show electronic devices using a semiconductor device of the present invention. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, preferred embodiment modes of the present invention will be described with reference to the attached drawings. However, the present invention is implemented in many other modes. As is easily known to a person skilled in the art, the mode and the detail of the invention can be variously changed without departing from the purpose and the range of the present invention. Thus, the present invention is not interpreted while limiting to the following description of the embodiment mode. A method for manufacturing a semiconductor device of the present invention is described. FIG. 1A shows a top view of an active layer 101 and a gate electrode 102 functioning as a mask, at the time of performing ion implantation to form an Lov region. In addition, a cross-sectional view taken along a line A-A′ in FIG. 1A is shown in FIG. 1B. Arrow show an implantation direction at the time of ion implantation and obliquely intersect with a surface of the active layer 101. The active layer 101 and the gate electrode 102 overlap each other with a gate insulating film 103 therebetween. An exposed region 104 without being overlapped with the gate electrode 102 is disposed closer to a dopant implantation direction side than a region 105 of the active layer 101 that is overlapped with the gate electrode 102. Namely, an edge portion 106 of the gate electrode 102 overlapping the active layer 101, which is surrounded by a broken line, is directed to the implantation direction side. According to the above structure, a dopant is implanted in a part of the region 105 of the active layer 101 that is overlapped with the gate electrode 102 to form an Lov region 107 at the time of ion implantation. In addition, source/drain regions 108, and a channel formation region 109 can separately be formed by the ion implantation. In FIGS. 1A and 1B, the two Lov regions 107 are formed to sandwich the channel formation region 109, and the source/drain regions 108 are formed to sandwich the channel formation region 109 and the two Lov regions 107. In the case of forming an Lov region only on either the source region side or the drain region side, only one edge portion of the gate electrode overlapping the active layer may be directed to the implantation direction. Alternatively, the edge portion of the gate electrode overlapping the active layer is directed to the implantation direction on only one side. On the other side, the region overlapped with the gate electrode and the exposed region of the active layer are made to be in contact with each other along the implantation direction. Subsequently, the case of manufacturing a TFT without an Lov region by obliquely performing ion implantation is described. FIG. 2A shows a top view of an active layer 201 and a gate electrode 202 functioning as a mask, at the time of obliquely performing ion implantation. A cross-sectional view taken along a line A-A′ in FIG. 2A is shown in FIG. 2B. A cross-sectional view taken along a line B-B′ in FIG. 2A is shown in FIG. 2C. A cross-sectional view taken along a line C-C′ in FIG. 2A is shown in FIG. 2D. Arrows show an implantation direction at the time of ion implantation and obliquely intersect with a surface of the active layer 201. The active layer 201 and the gate electrode 202 overlap each other with a gate insulating film 203 therebetween. In FIGS. 2A to 2D, an exposed region 204 without being overlapped with the gate electrode 202 and a region 205 of the active layer 201 that is overlapped with the gate electrode 202 are disposed to be in contact with each other along a dopant implantation direction. According to the above structure, a dopant can be implanted only in the exposed region 204 without being overlapped with the gate electrode 202, and a source/drain region can be formed in the region 204 at the time of ion implantation. In addition, a channel formation region can be formed in the region 205 of the active layer 201 that is overlapped with the gate electrode 202 by the ion implantation. Subsequently, a layout of each transistor in the case of forming a TFT having an Loff region and a TFT having an Lov region over one substrate is described. FIG. 6A shows a top view of a pixel portion 1301, and a signal line driver circuit 1302 and a scanning line driver circuit included in a driver circuit, which are formed over one substrate 1300. In FIG. 6A, arrows show the dopant implantation direction. A part of the signal line driver circuit 1302 shown in FIG. 6A is enlarged and is shown in FIG. 6B. Further, a part of the pixel portion 1301 shown in FIG. 6A is enlarged and is shown in FIG. 6C. In a TFT having an Lov region that is used for the signal line driver circuit 1302, an edge portion 1313 of a gate electrode 1312 overlapping an active layer 1311 is directed to the implantation direction side as shown in FIG. 6B. In the case of forming an Lov region only on either a source region side or a drain region side, only one edge portion 1323 of a gate electrode 1322 overlapping an active layer 1321 may be directed to the implantation direction. Alternatively, only on one side of the source region side or the drain region side, the edge portion of the gate electrode overlapping the active layer is directed to the implantation direction. On the other side, a region that is overlapped with the gate electrode and an exposed region of the active layer are made to be in contact with other along the implantation direction. FIG. 6D shows a cross-sectional view taken along a line A-A′ in FIG. 6B after ion implantation. As shown in FIG. 6D, an Lov region 1314 and an Lov region 1324 can be formed in the active layer 1311 and the active layer 1321 respectively by ion implantation from an oblique implantation direction. As shown in FIG. 6C, a TFT 1340 without an Lov region which is used for the pixel portion 1301 is disposed so that a region of an active layer 1331 that is overlapped with a gate electrode 1333 and an exposed region of the active layer 1331 are in contact with each other along the implantation direction. In other words, an edge portion 1336 of the gate electrode 1333 overlapping the active layer 1331 is along the implantation direction. Similarly, a TFT 1341 without an Lov region is disposed so that a region of an active layer 1332 that is overlapped with a gate electrode 1334 and the exposed region of the active layer 1332 are in contact with each other along an implantation direction. In other words, an edge portion 1337 of the gate electrode 1334 overlapping the active layer 1332 is along the implantation direction. FIG. 6E shows a cross-sectional view taken along a line B-B′ in FIG. 6C after ion implantation. As shown in FIG. 6E, only a channel formation region 1343, source/drain regions 1342 can be formed in the active layer 1331 by performing ion implantation from an oblique implantation direction. In addition, only a channel formation region, source/drain regions can be formed also in the active layer 1332, though not shown. Thus, as for a semiconductor device manufactured by using a manufacturing method of the present invention, all positions of Lov regions with respect to channel formation regions are uniform on the implantation direction side, as long as the TFTs have the same conductivity. In other words, each direction from the Lov region to the channel formation region in the plurality of TFTs is consistent with each other. In TFTs in which a source region and a drain region are in contact with a channel formation region, a channel formation region and a source/drain region are in contact with each other along the implantation direction, as long as the TFTs have the same conductivity. In TFTs having Loff regions, channel formation regions and the Loff regions are in contact with each other along the implantation direction, as long as the TFTs have the same conductivity. In TFTs having offset regions, positions of the offset regions with respect to channel formation regions is uniform on an opposite side of the implantation direction side, as long as the TFTs have the same conductivity. With reference to FIGS. 6A to 6E, an example of forming a TFT in which a source region and a drain region are in contact with a channel formation region over a substrate provided with a TFT having an Lov region is described. However, the present invention is not limited to this structure. In the case of forming a TFT having an Loff region and a TFT having an Lov region over one substrate, an edge portion of a resist mask overlapping an active layer may be directed to be along an implantation direction in a TFT in which an Loff region is formed. According to the above structure of the present invention, a TFT having an Lov region can separately be formed over a substrate provided with a TFT having an Loff region, a TFT in which source/drain regions are in contact with a channel formation region, and the like without providing a resist mask for forming an Lov region. Consequently, the number of resist masks and steps can be reduced, and a manufacturing cost can also be reduced. In addition, throughput in a step of ion implantation can be improved. Subsequently, a layout of a TFT having an Lov region in a semiconductor device of the present invention is described. FIG. 8A shows a top view of a TFT having an Lov region. Reference numeral 401 denotes an active layer; 402, a gate electrode; and 403, an Lov region. Arrows correspond to a dopant implantation direction at the time of forming the Lov region 403. In addition, the Lov region 403 is provided only on either side of a source region or a drain region and is directed to a dopant implantation direction side. FIG. 8B shows a top view of another TFT having an Lov region. Reference numeral 411 denotes an active layer; 412, a gate electrode; and 413a and 413b, Lov regions. Arrows correspond to a dopant implantation direction at the time of forming the Lov regions 413a and 413b. In FIG. 8B, the Lov regions 413a and 413b are directed to a dopant implantation direction side. FIG. 8C shows a top view of another TFT having an Lov region. Reference numeral 421 denotes an active layer; 422, a gate electrode; and 423a, 423b, 424a, and 424b, Lov regions. Arrows correspond to a dopant implantation direction at the time of forming the Lov regions 423a, 423b, 424a, and 424b. In FIG. 8C, the Lov regions 423a, 423b, 424a, and 424b are directed to a dopant implantation direction side. FIG. 8D shows a top view of another TFT having an Lov region. Reference numeral 431 denotes an active layer; 432a and 432b, gate electrodes; and 433a and 433b, Lov regions. Arrows correspond to a dopant implantation direction at the time of forming the Lov regions 433a and 433b. In FIG. 8D, the Lov regions 433a and 433b are directed to a dopant implantation direction side. The Lov region 433a is overlapped with the gate electrode 432a, and the Lov region 433b is overlapped with the gate electrode 432b. An edge portion 435a of the gate electrode 432a overlapping the active layer 431 is along the implantation direction. Further, an edge portion 435b of the gate electrode 432b overlapping the active layer 431 is along the implantation direction. As shown in FIGS. 8A to 8D, TFTs having various structures can be manufactured according to the present invention. The layouts of TFTs shown in the figures are merely examples, and the present invention is not limited to the structures shown in FIGS. 8A to 8D. Subsequently, a method for manufacturing a transistor having an offset gate structure is described. According to a method for manufacturing a semiconductor device of the present invention, a transistor having an offset gate structure in which a gate electrode does not overlap a source region or a drain region can also be formed over a substrate provided with a transistor having an Lov region, a transistor having an Loff region, or a transistor in which a source region or a drain region is in contact with a channel formation region. In a transistor having an offset gate structure, a region between a source region or a drain region and a region of an active layer that is overlapped with a gate electrode is referred to as an offset region. An electric field in the vicinity of a drain region is relieved and a transistor can be made pressure tightness high by providing an offset region on a drain region side. FIG. 5A shows a top view of an active layer 801 and a gate electrode 802 functioning as a mask, at the time of obliquely performing ion implantation. A cross-sectional view taken along a line A-A′ in FIG. 5A is shown in FIG. 5B. Arrow show an implantation direction at the time of ion implantation and obliquely intersect with a surface of the active layer 801. The active layer 801 and the gate electrode 802 overlap each other with a gate insulating film 803 therebetween. In the present invention, a region 805 of the active layer 801 that is overlapped with the gate electrode 802 is disposed closer to a dopant implantation direction side than an exposed region 804 without being overlapped with the gate electrode 802. Namely, an edge portion 806 of the gate electrode 802 overlapping the active layer 801, which is surrounded by a broken line, is directed in an opposite side of the implantation direction. According to the above structure, an offset region 807 in which a dopant is blocked by the gate electrode 802 and is not implanted or is hard to be implanted compared to other exposed regions can be formed in a part of the exposed region 804 of the active layer 801 without being overlapped with the gate electrode 802 at the time of ion implantation. According to the above ion implantation, source/drain regions 808 and a channel formation region 809 can separately be formed in the exposed region 804 and the region 805 overlapped with the gate electrode 802, respectively. In FIGS. 5A and 5B, the two offset regions 807 are formed to sandwich the channel formation region 809, and the source/drain regions 808 are formed to sandwich the channel formation region 809 and the two offset regions 807. Length of the offset region in an implantation direction (offset length) can be adjusted by an incidence angle of a dopant to an active layer at the time of ion implantation. In the case of forming an offset region only on either a source region side or a drain region side, only one edge portion of a gate electrode overlapping an active layer may be directed in an opposite side of an implantation direction. In the other edge portion, a region overlapped with the gate electrode and an exposed region of the active layer are disposed to be in contact with each other along the implantation direction. According to the above structure of the present invention, a TFT having an Lov region can separately be formed over a substrate provided with a TFT having an offset gate structure without providing a resist mask for forming an Lov region. Consequently, the number of resist masks and steps can be reduced, and a manufacturing cost can also be reduced. In addition, throughput in a step of ion implantation can be improved. A cluster of crystal grains made of single crystal elongating along a scanning direction can be formed by using a continuous wave laser for crystallization of a semiconductor film used as an active layer. Thus, mobility of a TFT used for a thin film chip can be improved by crystallizing a semiconductor film using a continuous wave laser. FIG. 3A shows a state of crystallizing a thin semiconductor film 1601 formed over a substrate 1600 by using a continuous wave laser beam. After crystallizing the semiconductor film 1601 as shown in FIG. 3A, the semiconductor film 1601 is patterned, and a gate electrode, a mask, or the like are formed. Thereafter, doping is performed as shown in FIG. 3B. The semiconductor film 1601 may be patterned before crystallization by a laser beam, or may be patterned after crystallization. An implantation direction at the time of doping is set oblique to a semiconductor film (a semiconductor film 1604 after patterning in FIG. 3B), as indicated by arrows of continuous lines. A plurality of integrated circuits is formed over the substrate 1600 by activating a dopant and forming various insulating films, wirings, or the like. After the integrated circuits are formed, the substrate 1600 is divided, thereby forming a thin film chip 1603 in which the integrated circuits are separated from each other, as shown in FIG. 3C. Subsequently, a layout of each transistor in a thin film chip is described, in which a TFT in which a source region and a drain region are in contact with a channel formation region and a TFT having an Lov region are formed. FIG. 4A shows an external view of a thin film chip. As for a thin film chip shown in FIG. 4A, an integrated circuit 301 formed by using a thin semiconductor film, and a connection terminal 302 are formed over a substrate 300. In FIG. 4A, arrows show a dopant implantation direction. For example, a TFT in which a source region and a drain region are in contact with a channel formation region and a TFT having an Lov region are formed in the integrated circuit 301. FIG. 4B shows a top view of the TFT having an Lov region, which is included in the integrated circuit 301, and FIG. 4C shows a top view of the TFT, in which a source region and a drain region are in contact with a channel formation region, which is included in the integrated circuit 301. In the TFT having an Lov region, an edge portion 313 of a gate electrode 312 overlapping an active layer 311 is directed to the implantation direction side as shown in FIG. 4B. In the case of forming an Lov region only on either a source region side or a drain region side, only one edge portion 323 of a gate electrode 322 overlapping an active layer 321 may be directed to the implantation direction. Alternatively, an edge portion of the gate electrode overlapping the active layer may be directed to the implantation direction only on one side of the source region side or the drain region side. On the other side, a region overlapped with the gate electrode and an exposed region of the active layer may be disposed to be in contact with each other along the implantation direction. FIG. 4D shows a cross-sectional view taken along a line A-A′ in FIG. 4B after ion implantation. As shown in FIG. 4D, an Lov region 314 and an Lov region 324 can be formed in the active layer 311 and the active layer 321 respectively by the ion implantation from an oblique implantation direction. As shown in FIG. 4C, a TFT 340 in which a source region and a drain region are in contact with a channel formation region is disposed so that a region of an active layer 331 that is overlapped with a gate electrode 333 and an exposed region of the active layer 331 are in contact with each other along the implantation direction. In other words, an edge portion 336 of the gate electrode 333 overlapping the active layer 331 is along the implantation direction. FIG. 4E shows a cross-sectional view taken along a line B-B′ in FIG. 4C after ion implantation. As shown in FIG. 4E, only a channel formation region 343 and source/drain regions 342 can be formed in the active layer 331 even by performing ion implantation from an oblique implantation direction. With reference to FIGS. 4A to 4E, an example of forming a TFT in which a source region and a drain region are in contact with a channel formation region over a substrate provided with a TFT having an Lov region is described. However, the present invention is not limited to this structure. In the case of forming a TFT having an Loff region and a TFT having an Lov region over one substrate, an edge portion of a resist mask overlapping an active layer may be along an implantation direction in a TFT in which an Loff region is formed. In the case of forming a TFT having an offset region over a substrate provided with a TFT having an Lov region, an edge portion of a gate electrode overlapping an active layer in a TFT having an offset region may be directed in an opposite side of the implantation direction. Thus, as for a semiconductor device manufactured by using a manufacturing method of the present invention, all positions of Lov regions with respect to channel formation regions are uniform on the implantation direction side, as long as the TFTs have the same conductivity. In TFTs in which a source region and a drain region are in contact with a channel formation region, a channel formation region and a source/drain region are in contact with each other along the implantation direction, as long as the TFTs have the same conductivity. In TFTs having Loff regions, channel formation regions and the Loff regions are in contact with each other along the implantation direction, as long as the TFTs have the same conductivity. In TFTs having offset regions, positions of the offset regions with respect to channel formation regions is uniform on an opposite side of the implantation direction side, as long as the TFTs have the same conductivity. According to the above structure of the present invention, a TFT having an Lov region can separately be formed over a substrate provided with a TFT having an Loff region, a TFT in which a source region and a drain region are in contact with a channel formation region, or the like without providing a resist mask for forming an Lov region. Consequently, the number of resist masks and steps can be reduced, and a manufacturing cost can also be reduced. In addition, throughput in a step of ion implantation can be improved. Subsequently, states of mounting a thin film chip formed by using the above manufacturing method on a substrate over which a pixel portion is formed is described with reference to FIGS. 7A and 7B. In FIG. 7A, a pixel portion 6002 and a scanning line driver circuit 6003 are formed over a substrate 6001. Then, a signal line driver circuit formed in a thin film chip 6004 is mounted on the substrate 6001. Specifically, the signal line driver circuit formed in the thin film chip 6004 is attached to the substrate 6001 and is electrically connected to the pixel portion 6002. In addition, reference numeral 6005 denotes an FPC. Electric potential of power supply, various signals, and the like are supplied to each of the pixel portion 6002, the scanning line driver circuit 6003, and the signal line driver circuit formed on the thin film chip 6004 through the FPC 6005. In FIG. 7B, a pixel portion 6102 and a scanning line driver circuit 6103 are formed over a substrate 6101. Then, a signal line driver circuit formed in a thin film chip 6104 is further mounted on an FPC 6105 that is mounted on the substrate 6101. Electric potential of power supply, various signals, and the like are supplied to each of the pixel portion 6102, the scanning line driver circuit 6103, and the signal line driver circuit formed on the thin film chip 6104 through the FPC 6105. A method for mounting a thin film chip is not particularly limited, and a known COG, wire bonding, TAB, or the like can be used. A position where a thin film chip is mounted is not limited to the position shown in FIGS. 7A and 7B, as long as electrical connection is possible. An example of forming only a signal line driver circuit in a thin film chip is shown in FIGS. 7A and 7B; however, a scanning line driver circuit may be formed in a thin film chip, or a controller, a CPU, a memory, or the like may be formed in a thin film chip and be mounted. Not a whole signal line driver circuit or scanning line driver circuit but only a part of a circuit constituting each driver circuit may be formed in a thin film chip. In a semiconductor display device in which a driver circuit is mounted as a thin film chip, a transistor used for a pixel portion is not limited to a TFT formed of an amorphous semiconductor film such as amorphous silicon. The TFT may be a TFT using a microcrystalline semiconductor film or a polycrystalline semiconductor film. It may be a transistor formed by using single crystal silicon or a transistor using SOI. Further, it may be a transistor using an organic semiconductor or a transistor using a carbon nanotube. A yield can be improved and a process can easily be optimized to characteristics of each circuit by separately forming an integrated circuit such as a driver circuit in a thin film chip and mounting it, compared with the case of forming all circuits over a substrate provided with a pixel portion. Subsequently, a specific method for manufacturing a semiconductor display device of the present invention is described. Here, an n-channel TFT having an Lov region which is used for a driver circuit, a p-channel TFT in which a source region and a drain region are in contact with a channel formation region and which is used for a driver circuit, and an n-channel TFT having an Loff region which is used for a pixel portion are exemplified for explanation. First, a base film 501 is formed on an insulating surface of a substrate 500 as shown in FIG. 10A. A glass substrate such as barium borosilicate glass or aluminoborosilicate glass, a quartz substrate, a ceramic substrate, or the like can be used as the substrate 500. Further, a metal substrate including an SUS substrate or a silicon substrate on a surface of which an insulating film is formed may be used. Although a substrate made from a synthetic resin having flexibility, such as plastics, generally tends to have a lower heat resistance temperature compared to the above described substrate, it can be used as the substrate 500 as long as it can withstand the process temperature in the manufacturing step. The base film 501 is formed in order to prevent an alkaline metal such as Na or an alkaline earth metal, contained within the substrate 500 from diffusing into a semiconductor film and exerting an adverse influence on semiconductor device characteristics. The base film 501 is therefore formed by using an insulating film capable of suppressing the diffusion of an alkaline metal or an alkaline earth metal into the semiconductor film, such as a silicon oxide film, a silicon nitride film, or a silicon nitride oxide film. In this embodiment mode, a silicon nitride oxide film is formed by plasma CVD to have a film thickness of from 10 nm to 400 nm (preferably from 50 nm to 300 nm). Note that the base film 501 may be a single layer, or may be a laminate of a plurality of insulating films. It is effective to form a base film in order to prevent impurity diffusion in the case of using a substrate that contains a certain amount of an alkaline metal or an alkaline earth metal, such as a glass substrate, an SUS substrate, or a plastic substrate. However, a base film is not necessarily required to be formed when using a quartz substrate or the like, with which impurity diffusion does not become a problem. Subsequently, a semiconductor film 502 is formed without exposing to atmospheric air, after forming the base film 501 by PCVD. A film thickness of the semiconductor film 502 is set from 25 nm to 100 nm (preferably from 30 nm to 60 nm). Note that the semiconductor film 502 may be an amorphous semiconductor or a polycrystalline semiconductor. Further, the semiconductor can use not only silicon but also silicon germanium. It is preferable that germanium concentration be on the order of from 0.01 atomic % to 4.5 atomic % when silicon germanium is used. Next, the semiconductor film 502 is crystallized by a laser crystallization method as shown in FIG. 10A. When a polycrystalline semiconductor is used for the semiconductor film 502, an amorphous semiconductor is formed first. Then, the amorphous semiconductor is crystallized by using a known crystallization method. A method for performing crystallization by RTA or heating using an annealing furnace, a method for performing crystallization by laser beam irradiation, a method for performing crystallization by using a catalyst metal, a method for performing crystallization by using infrared light, or the like can be given as a known method of crystallization. In addition, these crystallization methods may be combined to perform crystallization. In the case of using a laser, a pulsed laser typified by an excimer laser, a YAG laser, a YVO4 laser, or the like can be used to perform crystallization. For example, in the case of using a YAG laser, a wavelength of a second harmonic, which tends to easily be absorbed in the semiconductor film, is employed. An oscillating frequency is set from 30 kHz to 300 kHz, energy density is set from 300 mJ/cm2 to 600 mJ/cm2 (typically from 350 mJ/cm2 to 500 mJ/cm2), and scanning speed may be set so that several irradiation shots can be emitted at an arbitrary point. In addition, a crystal having a large grain size can be obtained by laser beam irradiation of from a second harmonic to a fourth harmonic of a fundamental wave with the use of a solid laser capable of continuously oscillating in crystallization of an amorphous semiconductor film. Typically, a second harmonic (532 nm) or a third harmonic (355 nm) of an Nd:YVO4 laser (fundamental wave of 1064 nm) is preferably employed. A laser beam emitted from a continuous wave YVO4 laser is converted to a harmonic by a nonlinear optical device to have an output power of 10 W. There is also a method for emitting a harmonic by putting YVO4 crystals and non-linear optical elements in a resonator. Preferably, the laser beam is shaped by using an optical system so that it becomes a rectangular shape or an elliptical shape on an irradiation face, and is radiated to an object to be treated. Energy density at the time needs to be on the order of from 0.01 MW/cm2 to 100 MW/cm2 (preferably from 0.1 MW/cm2 to 10 MW/cm2). Then, the semiconductor film 502 is moved relative to a laser beam at the rate of approximately from 10 cm/sec to 2000 cm/sec to be irradiated therewith. A known gas laser or solid laser of continuous wave can be used as a continuous wave laser. As the gas laser, an Ar laser, a Kr laser, and the like are cited. As the solid laser, a YAG laser, a YVO4 laser, a YLF laser, a YAlO3 laser, a Y2O3 laser, a glass laser, a ruby laser, an alexandrite laser, a Ti:sapphire laser, and the like are cited. A harmonic to a fundamental wave can be obtained by using a non-linear optical element. Note that mobility of a TFT can be increased by arranging a scanning direction of a laser beam and a moving direction of a carrier in a channel formation region in the same direction as much as possible. Island semiconductor films 503 to 505 used as an active layer are formed as shown in FIG. 10B by patterning the semiconductor film 502 after the crystallization. A film thickness of the island semiconductor films 503 to 505 is set from 25 nm to 100 nm (more preferably, from 30 nm to 60 nm). A top view corresponding to FIG. 10B is shown in a region surrounded by a broken line 600. A cross-sectional view taken along a line A-A′ and a cross-sectional view taken along a line B-B′ within the broken line 600 correspond to FIG. 10B. Subsequently, a gate insulating film 506 is formed to cover the island semiconductor films 503 to 505 as shown in FIG. 10C. A film thickness of the gate insulating film is decreased on the order of from 10 nm to 20 nm during later dry etching for forming a gate electrode; therefore, it is preferable that the film thickness of the gate insulating film be set with the decrease in mind. Specifically, the gate insulating film is formed to have a thickness on the order of from 40 nm to 150 nm (more preferably, from 60 nm to 120 nm). Silicon oxide, silicon nitride, silicon nitride oxide, and the like can be used for the gate insulating film, for example. Further, plasma CVD, sputtering, and the like can be used as a film formation method. For example, in the case of forming the gate insulating film using silicon oxide by plasma CVD, film formation may be performed by using a mixed gas of tetraethyl orthosilicate (TEOS) and O2, at a reaction pressure of 40 Pa, a substrate temperature of from 300° C. to 400° C., and a high-frequency (13.56 MHz) power density of from 0.5 W/cm2 to 0.8 W/cm2. Further, aluminum nitride can also be used for the gate insulating film. The thermal conductivity of aluminum nitride is relatively high, and heat generated from a TFT can efficiently be dissipated. In addition, a gate insulating film in which aluminum nitride is laminated after forming silicon oxide, silicon oxynitride, or the like, which contains no aluminum, may also be used as the gate insulating film. Subsequently, a conductive film 507 is formed on the gate insulating film 506 as shown in FIG. 10D. The conductive film 507 may be a single layer, or may have a laminated structure including a plurality of layers such as two or three layers, if necessary. In this embodiment mode, the conductive film 507 is formed using W to have a film thickness of 300 nm. Specifically, an element selected from Ta, W, Ti, Mo, Al, and Cu, or an alloy or a compound having one of these elements as its main component may be used in forming each conductive film. For example, a combination of a conductive film in which Ta is used in a first layer and W is used in a second layer, a conductive film in which TaN is used in the first layer and Al is used in the second layer, and a conductive film in which TaN is used in the first layer and Cu is used in the second layer can all be considered. Further, an AgPdCu alloy may be used in either of the first layer or the second layer. A three layer structure in which W, an alloy of Al and Si (Al—Si), and TiN are sequentially laminated may be used. Tungsten nitride may also be used in place of W, an alloy of Al and Ti (Al—Ti) may also be used in place of the alloy of Al and Si (Al—Si), and Ti may be used in place of TiN. However, in the case of forming a plurality of conductive films, such a material that can secure an etching selectivity ratio is used in order to have a difference in the width of the conductive film in each layer in the channel length direction after etching. For example, the conductive film 507 may be formed by laminating a conductive film made of TaN having a thickness of from 20 nm to 100 nm and a conductive film made of W having a thickness of from 100 nm to 400 nm. In this case, a film of TaN is formed at film formation speed of approximately 40 nm/min. This is achieved by using a Ta target having a purity of 99.99%, with an internal chamber temperature set to room temperature, a gas flow rate of Ar set to 50 ml/min, a gas flow rate for N2 set to 10 ml/min, an internal chamber pressure set to 0.6 Pa, and a film formation electric power set to 1 kW. In addition, a film of W is formed at film formation speed of approximately 390 nm/min. This is achieved by using a W target having a purity of 99.99%, with an internal chamber temperature set to 230° C., a gas flow rate of Ar set to 100 ml/min, an internal chamber pressure set to 1.5 Pa, and a film formation electric power set to 6 kW. Note that it is important to select an optimal etching gas according to a material of a conductive film. Further, a material of each conductive layer is not limited to the one described in this embodiment mode. Subsequently, the conductive film 507 is patterned to form gate electrodes 508 to 510 as shown in FIG. 11A. In this embodiment mode, etching is performed by using inductively coupled plasma (ICP) etching. Etching is performed by using a mixed gas of Cl2 and CF4 as an etching gas and applying RF (13.56 MHz) electric power of 3.2 W/cm2 under the pressure of 1 Pa to generate plasma. RF (13.56 MHz) power of 224 mW/cm2 is applied to a substrate side (sample stage), thereby applying a substantially negative self-bias voltage. An etching rate of a W film is approximately 100 nm/min on this condition. According to the etching, side faces of the gate electrodes 508 to 510 become slightly tapered shapes. When etching is performed so that no conductive film residue remains, a surface of the gate insulating film 506 that is not covered with the gate electrodes 508 to 510 may undergo etching on the order of from 5 nm to 10 nm or more. A top view corresponding to FIG. 11A is shown in a region surrounded by a broken line 601. A cross-sectional view taken along a line A-A′ and a cross-sectional view taken along a line B-B′ in the broken line 601 correspond to FIG. 11A. Subsequently, as shown in FIG. 11B, an impurity (dopant) imparting n-type conductivity is added to the island semiconductor films 503 to 505, using the gate electrodes 508 to 510 as a mask (first doping treatment). Doping is performed by ion implantation. Doping is performed with a dose amount of from 1×1013 atoms/cm2 to 1×1015 atoms/cm2, and an acceleration voltage of from 30 kV to 90 kV. A Group 5 element such as P, As, or Sb, or a Group 6 element such as S, Te, or Se, which functions as a donor, may be used as the impurity element imparting n-type conductivity. P is used in this embodiment mode. First impurity regions 511 to 515 are formed in a self-aligned manner according to the first doping treatment. An impurity element imparting n-type conductivity is added to the first impurity regions 511 to 515 at a concentration range of from 1×1018 atoms/cm3 to 1×1020 atoms/cm3. A top view corresponding to FIG. 11B is shown in a region surrounded by a broken line 602. A cross-sectional view taken along a line A-A′ and a cross-sectional view taken along a line B-B′ in the broken line 602 correspond to FIG. 11B. In addition, reference numeral 516 shows an implantation direction at the time of doping. In ion implantation shown in FIG. 11B, an implantation direction is directed nearly perpendicular to the substrate 500 from a top face of the substrate 500. Next, as shown in FIG. 11C, a resist mask 520 is formed to cover the whole island semiconductor film 504 and a part of the island semiconductor film 505, and then, a second doping treatment is performed. In the second doping treatment, an acceleration voltage is set from 50 kV to 150 kV, and a dose amount is set from 1×1015 atoms/cm2 to 1×1017 atoms/cm2. A top view corresponding to FIG. 11C is shown in a region surrounded by a broken line 603. A cross-sectional view taken along a line A-A′ and a cross-sectional view taken along a line B-B′ in the broken line 603 correspond to FIG. 11C. In addition, arrows show an implantation direction at the time of doping. In the second doping treatment, an implantation direction is kept oblique to the surface of the island semiconductor film 503 so that an impurity is added to a part of an overlapping region of the gate electrode 508 and the island semiconductor film 503. Note that an edge portion 521 of the gate electrode 508 overlapping the island semiconductor film 503 is directed to the implantation direction. In addition, a region of the island semiconductor film 505 that is overlapped with the resist mask 520 and an exposed region without being overlapped are disposed to be in contact with each other along the implantation direction. According to the second doping treatment, in the island semiconductor film 505, a second impurity region 526 is formed in a region overlapped with the resist mask 520 and a third impurity region 527 which is formed by further adding an impurity to the first impurity regions 514 and 515 is formed. In addition, in the island semiconductor film 503, a fourth impurity region 524 is formed in a region overlapped with the gate electrode 508 and a third impurity region 525 which is formed by further adding an impurity to the first impurity region 511 is formed. An impurity element imparting n-type conductivity is added to the second impurity region 526 at a concentration range of from 5×1017 atoms/cm3 to 5×1019 atoms/cm3, and an impurity element imparting n-type conductivity is added to the third impurity region 525 at a concentration range of from 1×1019 atoms/cm3 to 5×1021 atoms/cm3. A concentration of the impurity element in the fourth impurity region 524 depends also on an incidence angle of a dopant, and has a concentration gradient to some extent in a channel-length direction. The concentration of the impurity element in the fourth impurity region 524 is lower than that in the third impurity region 525. The second impurity region 526 corresponds to an Loff region; the third impurity region 527, a source/drain region; the third impurity region 525, a source/drain region; and the fourth impurity region 524, an Lov region. Note that the island semiconductor 504 in which a p-channel TFT is formed does not need to be doped with an impurity imparting n-type conductivity by the first doping treatment shown in FIG. 11B. Therefore, it may be covered with a resist mask at the time of the first doping treatment. The resist mask may not be provided intentionally for reducing the number of resist masks and concentration of an impurity imparting p-type conductivity may be increased, so that conductivity of the island semiconductor film may be inverted to p-type. In this embodiment mode, the case of inverting conductivity of the island semiconductor film is described. As shown in FIG. 12A, the island n-channel semiconductor films 503 and 505 are covered with a resist mask 530 made of a resist, and an impurity imparting p-type conductivity is doped into the island semiconductor film 504 (third doping treatment). In the third doping treatment, the gate electrode 509 functions as a mask, and a fifth impurity region 531 in which an impurity element imparting p-type conductivity is added to the island semiconductor film 504 used for a p-channel TFT is formed. The fifth impurity region 531 is formed by ion implantation using diborane (B2H6) in this embodiment mode. In the fifth impurity region 531, a doping treatment is performed so that concentration of an impurity element imparting p-type conductivity is from 2×1020 atoms/cm3 to 2×1021 atoms/cm3. Accordingly, p-type becomes dominant. Therefore, the fifth impurity region 531 functions as a source/drain region of a p-channel TFT. A top view corresponding to FIG. 12A is shown in a region surrounded by a broken line 604. A cross-sectional view taken along a line A-A′ and a cross-sectional view taken along a line B-B′ in the broken line 604 correspond to FIG. 12A. In addition, reference numeral 536 shows an implantation direction at the time of doping. In ion implantation shown in FIG. 12A, an implantation direction is directed nearly perpendicular to the substrate 500 from a top face of the substrate 500. In the case of forming an Lov region also in the p-channel TFT, an ion implantation direction is set oblique so that an impurity is added to a region of the island semiconductor film 503 that is overlapped with the gate electrode 509. According to the above described steps, impurity regions are formed in the island semiconductor films 503 to 505. Subsequently, a first interlayer insulating film 532 is formed to cover the island semiconductor films 503 to 505, the gate insulating film 506, and the gate electrodes 508 to 510 as shown in FIG. 12B. The first interlayer insulating film 532 can be formed by using an insulating film including silicon, such as silicon oxide, silicon nitride, or silicon oxynitride and has a thickness on the order of from 100 nm to 200 nm. Next, a heat treatment is performed in order to activate the impurity element added to the island semiconductor films 503 to 505. This step can be performed by thermal annealing using an annealing furnace, by laser annealing, or by rapid thermal annealing (RTA). For example, in the case of performing activation by thermal annealing, it is performed at a temperature of from 400° C. to 700° C. (preferably from 500° C. to 600° C.) under a nitrogen atmosphere containing oxygen at a concentration of equal to or less than 1 ppm, preferably equal to or less than 0.1 ppm. Further, a heat treatment is performed at a temperature of from 300° C. to 450° C. for from 1 hour to 12 hours under an atmosphere containing hydrogen of from 3% to 100%, thus performing hydrogenation of the island semiconductor film. This step is performed to terminate a dangling bond by thermally excited hydrogen. Plasma hydrogenation (using hydrogen excited by plasma) may also be performed as another means of hydrogenation. The activation treatment may be performed before forming the first interlayer insulating film 532. According to the series of above described steps, an n-channel TFT 533 having an Lov region, a p-channel TFT 534 in which a source region and a drain region are in contact with a channel formation region, and an n-channel TFT 535 having an Loff region can be formed over one substrate. A top view corresponding to FIG. 12B is shown in a region surrounded by a broken line 605. A cross-sectional view taken along a line A-A′ and a cross-sectional view taken along a line B-B′ in the broken line 605 correspond to FIG. 12B. Subsequently, a second interlayer insulating film 537 and a third interlayer insulating film 538 are formed to cover the first interlayer insulating film 532 as shown in FIG. 12C. An organic resin film, an inorganic insulating film, organic polysiloxane, or the like can be used for the second interlayer insulating film 537. In this embodiment mode, the second interlayer insulating film 537 is formed by using non-photosensitive acrylic that is one of organic resin films. Thereafter, the gate insulating film 506, the first interlayer insulating film 532, the second interlayer insulating film 537, and the third interlayer insulating film 538 are etched to form contact holes. Then, wirings 539 for forming a contact with the island semiconductor films 503 to 505 is formed. After the step shown in FIG. 12C, a step of manufacturing an element (display element) that can display gradation in accordance with an electrical signal, such as a liquid crystal cell or a light emitting element used for a semiconductor display device is performed. Note that the present invention is not necessarily limited to the manufacturing method described in this embodiment mode. The above described manufacturing method is specifically described as merely one embodiment mode of the present invention, and the present invention is not limited to the above embodiment mode. Various changes and modifications based on a technical idea of the invention are possible. Subsequently, a method for electrically connecting a wiring or a terminal provided over a substrate and a thin film chip is described. FIG. 9A shows a cross-sectional structure of a thin film chip connected to a wiring or a terminal for extending by a wire-bonding method. Reference numeral 901 denotes a substrate, and 902 denotes a thin film chip. The thin film chip 902 is attached to the substrate 901 with an adhesive 903. A semiconductor element 906 is provided in the thin film chip 902 and is electrically connected to a pad 907 functioning as a terminal, formed on the surface of the thin film chip 902 so as to be exposed. A wiring or a terminal 904 is formed on the substrate 901 shown in FIG. 9A, and the pad 907 and the wiring or the terminal 904 are connected through a wire 905. Subsequently, FIG. 9B shows a state that a thin film chip is connected to a substrate by a flip chip method. In FIG. 9B, a solder ball 913 is connected to a pad 912 that is formed on the surface of a thin film chip 911 to be exposed. Accordingly, a semiconductor element 914 formed in the thin film chip 911 is electrically connected to the solder ball 913 through the pad 912. The solder ball 913 is connected to a wiring or a terminal 916 formed on a substrate 915. As a method for connecting the solder ball 913 and the wiring or the terminal 916, various methods such as thermo-compression or thermo-compression added with ultrasonic vibration can be used. An underfilling may be provided between the thin film chip 911 and the substrate 915 to fill a gap between solder balls after the thermo-compression for enhancing mechanical strength of a connecting portion and efficiency of thermal diffusion of heat generated in the thin film chip. The underfilling, although it is not always necessary to be used, can prevent poor electrical connection due to stress caused by mismatch of thermal expansion coefficient of the substrate and the thin film chip. In the case of bonding by thermo-compression added with ultrasonic vibration, poor electrical connection can be prevented compared with the case of bonding solely by thermo-compression. Particularly, it is effective for the case where the number of bumps to be connected is approximately more than 300. The flip chip method is suitable for connection of a thin film chip having many terminals, since a pitch between pads is relatively kept wider than that of the case of a wire bonding method, even if the number of pads to be connected increases. Note that the solder ball may be formed by a droplet discharging method which discharges nano-particle dispersed liquid. Subsequently, FIG. 9C show a state that a thin film chip is connected to a substrate by using an anisotropic conductive resin. In FIG. 9C, a pad 922 that is formed on the surface of a thin film chip 921 to be exposed is electrically connected to a semiconductor element 924 formed in the thin film chip 921. The pad 922 is connected to a wiring or a terminal 926 formed on a substrate 925 through an anisotropic conductive resin 927. Note that a mounting method is not limited to the methods shown in FIGS. 9A to 9C. A wire bonding method and a flip chip method may be combined to mount a thin film chip. [Embodiment 1] In this embodiment, a relationship between an incidence angle of a dopant (impurity) in ion implantation and concentration of an Lov region is described. FIG. 13A shows a result of a relationship between an incident angle (Tilt angle) of a dopant to an island semiconductor film and width of an Lov region in a dopant implantation direction, which is found by simulation. FIG. 13A shows a result of simulation in the case of using P as a dopant. Specifically, it is assumed that a dose amount of P is 3×1015 atoms/cm2 and an acceleration voltage is 80 kV. It is also assumed that impurity concentration of an Lov region is equal to or more than ¼ of that of an exposed region without being covered with a gate electrode. In addition, FIG. 13A shows a relationship between an incident angle of a dopant and impurity concentration equivalent to ¼ of that of an exposed region without being covered with a gate electrode (equivalent to impurity concentration of a portion closest to a channel formation region in an Lov region). As shown in FIG. 13A, width of an Lov region increases, and on the contrary, impurity concentration of a portion closest to a channel formation region in an Lov region decreases, as an incidence angle increases. Even in the case where an incidence angle is 0° in FIG. 13A, that is, the case where a dopant is added in a direction perpendicular to a semiconductor film, an Lov region having a width of approximately 24 nm is formed. However, this is caused by thermal diffusion of a dopant. FIG. 13A shows that an incidence angle is preferably set approximately at least 15° to at most 80°, considering that a hot carrier effect is hard to be suppressed if width of an Lov region is too narrow and impurity concentration of an Lov region is too low. FIG. 13B shows a result of a relationship between an incidence angle of a dopant and width of an Lov region in a dopant implantation direction, which is found by simulation, in the case of using B as a dopant. Specifically, it is assumed that a dose amount of B is 2×1016 atoms/cm2 and an acceleration voltage is 80 kV. It is also assumed that impurity concentration of an Lov region is equal to or more than ¼ of that of an exposed region without being covered with a gate electrode. In addition, FIG. 13B shows a relationship between an incidence angle of a dopant and impurity concentration equivalent to ¼ of that of an exposed region without being covered with a gate electrode (equivalent to impurity concentration of a portion closest to a channel formation region in an Lov region). As shown in FIG. 13B, width of an Lov region increases, and on the contrary, impurity concentration of a portion closest to a channel formation region in an Lov region decreases, as an incidence angle increases. Even in the case where an incidence angle is 0° in FIG. 13B, that is, the case where a dopant is added in a direction perpendicular to a semiconductor film, an Lov region having a width of approximately 76 nm. However, this is caused by thermal diffusion of a dopant. FIG. 13B shows that an incidence angle is preferably set approximately at least 15° to at most 80°, considering that a hot carrier effect is hard to be suppressed if width of an Lov region is too narrow and impurity concentration of an Lov region is too low. When FIG. 13A and FIG. 13B are compared with each other, it is found that a relationship between an incidence angle, and width of an Lov region and impurity concentration of an Lov region changes depending also on the kind of a dopant. Therefore, it is preferable that a relationship between an incidence angle and width of an Lov region and impurity concentration of an Lov region is grasped, and then an incidence angle of a dopant in ion implantation is determined to a desired width of an Lov region and a desired impurity concentration of an Lov region. [Embodiment 2] In this embodiment, one mode of a semiconductor display device of the present invention is described. FIG. 14A is a block diagram of a semiconductor display device of this embodiment. A semiconductor display device shown in FIG. 14A has a pixel portion 701 having a plurality of pixels provided with a display element, a scanning line driver circuit 702 selecting each pixel portion, and a signal line driver circuit 703 controlling input of a video signal into a selected pixel. In FIG. 14A, the signal line driver circuit 703 includes a shift register 704 and an analog switch 705. A clock signal (CLK) and a start pulse signal (SP) are inputted to the shift register 704. When the clock signal (CLK) and the start pulse signal (SP) are inputted, a timing signal is generated in the shift register 704 and is inputted to the analog switch 705. In addition, a video signal is inputted to the analog switch 705. The video signal is sampled in the analog switch 705 according to the inputted timing signal and is supplied to a following row of a signal line. Next, a structure of the scanning line driver circuit 702 is described. The scanning line driver circuit 702 includes a shift register 706 and a buffer 707. In some cases, the scanning line driver circuit 702 may include a level shifter. By input of a clock signal (CLK) and a start pulse signal (SP) into the shift register 706, a selection signal is generated in the scanning line driver circuit 702. The generated selection signal is buffered and amplified by the buffer 707 and is then supplied to a corresponding scanning line. A gate of a transistor for one line of pixels is connected to the scanning line. The transistor for the one line of pixels must simultaneously be put into an ON state. Therefore, the one that is capable of handling a large electric current is used as the buffer 707. In the semiconductor display device shown in FIG. 14A, the signal line driver circuit 703 and the scanning line driver circuit 702 surrounded by a broken line can be formed in a thin film chip. Note that the present invention is not limited thereto, and one of a scanning line driver circuit and a signal line driver circuit may be formed over a substrate provided with the pixel portion 701 and the other may be formed in a thin film chip. Alternatively, only a part of the signal line driver circuit 703 and a part of the scanning line driver circuit 702 may be formed in a thin film chip. FIG. 14B shows an example that the scanning line driver circuit 702 and the analog switch 705 of the signal line driver circuit 703 are formed over a substrate provided with the pixel portion 701 and the shift register 704 of the signal line driver circuit 703 is formed in a thin film chip. A mode that not only a driver circuit for controlling operation of a display element, typified by a signal line driver circuit or a scanning line driver circuit but also a controller, a CPU, a memory, or the like is formed in a thin film chip and the thin film chip is mounted on a substrate over which a pixel portion is formed may be employed. Note that the structure shown in FIG. 14A or 14B is merely one mode of a semiconductor display device of the present invention, and a structure of a signal line driver circuit and a scanning line driver circuit is not limited thereto. For example, another circuit capable of selecting a signal line, such as a decoder circuit, may be used in place of the shift registers 704 and 706. [Embodiment 3] A structure of a light emitting device, which corresponds to one mode of a semiconductor device of the present invention, is described in this embodiment. A light emitting device includes a panel in which a light emitting element is sealed and a module in which an IC including a controller, or the like is mounted on the panel. FIG. 15A is a top view of a panel in which a transistor and a light emitting element formed over a first substrate are sealed with a sealant so as to be sandwiched between the first substrate and a second substrate. FIG. 15B corresponds to a cross-sectional view taken along a line A-A′ in FIG. 15A. A sealant 4005 is provided to surround a pixel portion 4002, a signal line driver circuit 4003, and a scanning line driver circuit 4004 which are provided over a first substrate 4001. A second substrate 4006 is provided over the pixel portion 4002, the signal line driver circuit 4003, and the scanning line driver circuit 4004. Thus, the pixel portion 4002, the signal line driver circuit 4003, and the scanning line driver circuit 4004 are sealed with the first substrate 4006, the sealant 4005, and the second substrate 4001, together with a filler 4007. The pixel portion 4002, the signal line driver circuit 4003, and the scanning line driver circuit 4004 that are provided over the first substrate 4001 have a plurality of transistors. In FIG. 15B, transistors 4008 and 4009 included in the signal line driver circuit 4003 and a transistor 4010 included in the pixel portion 4002 are exemplified. FIG. 15B corresponds to a cross-sectional view of a panel taken along a dopant implantation direction indicated by arrows. Therefore, it is difficult to illustrate a total image of each transistor along a channel-length direction; accordingly, only partial cross-sectional views of each transistor are shown here. However, the transistors 4008 and 4009 included in the signal line driver circuit 4003 have Lov regions, and the transistor 4010 included in the pixel portion 4002 has an Loff region. Reference numeral 4011 denotes a light emitting element, and a pixel electrode included in a light emitting element 4011 is electrically connected to a drain of the transistor 4010 through a wiring 4017. In addition, an opposite electrode of the light emitting element 4011 and a transparent conductive film 4012 are electrically connected to each other in this embodiment. Note that a structure of the light emitting element 4011 is not limited to the structure described in this embodiment. A structure of the light emitting element 4011 can appropriately be changed in response to a direction of light extracted from the light emitting element 4011 and conductivity of the transistor 4010. Various signals and electric potential supplied to the signal line driver circuit 4003, the scanning line driver circuit 4004, or the pixel portion 4002 are not illustrated in the cross-sectional view shown in FIG. 15B, but are supplied from a connection terminal 4016 through lead wirings 4014 and 4015. In this embodiment, the connection terminal 4016 is formed of the same conductive film as the pixel electrode included in the light emitting element 4011. The lead wiring 4014 is formed of the same conductive film as the wiring 4017. In addition, the lead wiring 4015 is formed of the same conductive film as gate electrodes included in each of the transistors 4008 to 4010. The connection terminal 4016 is electrically connected to a terminal included in an FPC 4018 through an anisotropic conductive film 4019. Glass, metal (typically, stainless steel), ceramics, or plastics can be used for the first substrate 4001 and the second substrate 4006. As plastics, an FRP (fiberglass-reinforced plastics) plate, a PVF (polyvinyl fluoride) film, a Mylar film, a polyester film, or an acrylic resin film may be used. Further, a sheet having a structure in which an aluminum foil is sandwiched between PVF films or Mylar films can also be used. However, the second substrate needs to be transparent in the case where the second substrate is situated in an extraction direction of light emitted from the light emitting element 4011. In such a case, a light transmitting material such as a glass plate, a plastic plate, a polyester film, or an acrylic film is used. Further, in addition to an inert gas such as nitrogen or argon, an ultraviolet curable resin or a thermosetting resin may be used as the filler 4007, and PVC (polyvinyl chloride), acrylic, polyimide, an epoxy resin, a silicone resin, PVB (polyvinyl butyral), or EVA (ethylene vinyl acetate) can be used. In this embodiment, nitrogen is used as the filler. The present invention can be applied not only to the light emitting device described in this embodiment but also to another semiconductor device. [Embodiment 4] A structure of a light emitting device, which corresponds to one mode of a semiconductor display device of the present invention, is described in this embodiment. A light emitting device includes a panel in which a light emitting element is sealed and a module in which an IC or the like formed of a single crystalline silicon wafer is mounted on the panel. FIG. 16A is a top view of a panel in which a transistor and a light emitting element formed over a first substrate are sealed with a sealant so as to be sandwiched between the first substrate and a second substrate. FIG. 16B corresponds to a cross-sectional view taken along a line A-A′ in FIG. 16A. A sealant 4105 is provided to surround a pixel portion 4102 and a scanning line driver circuit 4104 which are provided over a first substrate 4101. A second substrate 4106 is provided over the pixel portion 4102 and the scanning line driver circuit 4104. Thus, the pixel portion 4102 and the scanning line driver circuit 4104 are sealed with the first substrate 4101, the sealant 4105, and the second substrate 4106, together with a filler 4107. In addition, a signal line driver circuit 4103 formed in a thin film chip is mounted on a region different from a region surrounded by the sealant 4105 over the first substrate 4101. The pixel portion 4102 and the scanning line driver circuit 4104 that are provided over the first substrate 4101 have a plurality of transistors. In FIG. 16B, only a transistor 4110 included in the pixel portion 4102 is exemplified. Reference numeral 4111 denotes a light emitting element, and a pixel electrode included in a light emitting element 4111 is electrically connected to a drain of the transistor 4110 through a wiring 4117. In addition, an opposite electrode of the light emitting element 4111 and a transparent conductive film 4112 are electrically connected to each other in this embodiment. Note that a structure of the light emitting element 4111 is not limited to the structure described in this embodiment. A structure of the light emitting element 4111 can appropriately be changed in response to a direction of light extracted from the light emitting element 4111 and conductivity of the transistor 4110. Various signals and electric potential supplied to the signal line driver circuit 4103 formed in a thin film chip, the scanning line driver circuit 4104, and the pixel portion 4102 are not illustrated in the cross-sectional view shown in FIG. 16B, but are supplied from a connection terminal 4116 through lead wirings 4114 and 4115. In this embodiment, the connection terminal 4116 is formed of the same conductive film as the pixel electrode included in the light emitting element 4111. In addition, the lead wiring 4114 is formed of the same conductive film as the wiring 4117. Further, the lead wiring 4115 is formed of the same conductive film as a gate electrode included in the transistor 4110. The connection terminal 4116 is electrically connected to a terminal included in an FPC 4118 through an anisotropic conductive film 4119. Glass, metal (typically, stainless steel), ceramics, or plastics can be used for the first substrate 4101 and the second substrate 4106. As plastics, an FRP (fiberglass-reinforced plastics) plate, a PVF (polyvinyl fluoride) film, a Mylar film, a polyester film, or an acrylic resin film may be used. Further, a sheet having a structure in which an aluminum foil is sandwiched between PVF films or Mylar films can also be used. However, the second substrate needs to be transparent in the case where the second substrate is situated in an extraction direction of light emitted from the light emitting element 4111. In such a case, a light transmitting material such as a glass plate, a plastic plate, a polyester film, or an acrylic film is used. Further, in addition to an inert gas such as nitrogen or argon, an ultraviolet curable resin or a thermosetting resin may be used as the filler 4107, and PVC (polyvinyl chloride), acrylic, polyimide, an epoxy resin, a silicone resin, PVB (polyvinyl butyral), or EVA (ethylene vinyl acetate) can be used. In this embodiment, nitrogen is used as the filler. FIGS. 16A and 16B show an example that the signal line driver circuit 4103 is formed in a thin film chip and is mounted on the first substrate 4101; however, a circuit which can be formed in a thin film chip is not limited to the signal line driver circuit 4103. A scanning line driver circuit may be formed in a thin film chip, and only a part of a signal line driver circuit or a part of a scanning line driver circuit may be formed in a thin film chip. The present invention can be applied not only to a light emitting device described in this embodiment but also to another semiconductor device. [Embodiment 5] In this embodiment, an optical system used for irradiation of a continuous wave laser beam is described. FIGS. 18A to 18D show an optical system of this embodiment mode. An optical system shown in FIG. 18A has two cylindrical lenses 7001 and 7002. A beam spot of a laser beam entering from a direction indicated by an arrow is shaped through the two cylindrical lenses 7001 and 7002, and then the laser beam is radiated to an object to be treated 7003. Note that the cylindrical lens 7002 positioned closer to the object to be treated 7003 has a shorter focal length than that of the cylindrical lens 7001. In order to avoid return light and to perform uniform irradiation, the incidence angle of the laser beam to the object to be treated is set more than 0°, preferably in the range of from 5° to 30°. An optical system shown in FIG. 18B has a mirror 7005 and a planoconvex spherical lens 7006. A laser beam entering from a direction indicated by an arrow is reflected from the mirror 7005, and its beam spot is shaped through the planoconvex spherical lens 7006, and then is radiated to an object to be treated 7007. Note that a designer can appropriately determine a radius of curvature of the planoconvex spherical lens. Note that in order to avoid the return light and to perform uniform irradiation, an incidence angle of the laser beam to a substrate is set more than 0°, preferably in the range of from 5° to 30°. An optical system shown in FIG. 18C has mirrors 7010 and 7011, and lenses 7012, 7013, and 7014. A laser beam entering from a direction indicated by an arrow is reflected from the mirrors 7010 and 7011, and its beam spot is shaped through the lenses 7012, 7013, and 7014, and then is radiated to an object to be treated 7015. In order to avoid the return light and to perform uniform irradiation, an incidence angle of the laser beam to a substrate is set to be more than 0°, preferably in the range of from 5° to 30°. FIG. 18D shows an optical system in the case of combining four beam spots to form one beam spot. The optical system shown in FIG. 18D has six cylindrical lenses 7017 to 7022. Four laser beams from directions indicated by arrows enter the four cylindrical lenses 7019 to 7022, respectively. Beam spots of two laser beams shaped through the cylindrical lenses 7019 and 7021 are again shaped through the cylindrical lens 7017, and then the laser beams are radiated to an object to be treated 7023. On the other hand, beam spots of the other two laser beams shaped through the cylindrical lenses 7020 and 7022 are again shaped through the cylindrical lens 7018, and then the laser beams are radiated to the object to be treated 7023. Beam spots of each laser beam on the object to be treated 7023 are combined to form one beam spot by partially overlapping each other. Although it is possible for a designer to appropriately determine the focal length and the incidence angle of each lens, the focal length of the cylindrical lenses 7017 and 7018, which are positioned closest to the object to be treated 7023, are made shorter than that of the cylindrical lenses 7019 to 7022. For example, the focal length of the cylindrical lenses 7017 and 7018, which are positioned closest to the object to be treated 7023, is set 20 mm. The focal length of the cylindrical lenses 7019 to 7022 is set 150 mm. Each lens is disposed so that the incidence angle of the laser beam from the cylindrical lenses 7017 and 7018 to the object to be treated 7023 is 25° and the incidence angle of the laser beam from the cylindrical lenses 7019 to 7022 to the cylindrical lenses 7017 and 7018 is 10° in this embodiment. In order to avoid return light and to perform uniform irradiation, the incidence angle of the laser beam to a substrate is set more than 0°, preferably in the range of from 5° to 30°. FIG. 18D shows an example of combining four beam spots. In this case, an optical system has four cylindrical lenses corresponding to four laser oscillators and two cylindrical lenses corresponding to the four cylindrical lenses. The number of beam spots to be combined is not limited to this, and the number thereof may be at least 2 to at most 8. When n (n=2, 4, 6, 8) beam spots are combined, an optical system has n cylindrical lenses corresponding to n laser oscillators respectively and n/2 cylindrical lenses corresponding to the n cylindrical lenses. When n (n=3, 5, 7) number of the beam spots are combined, an optical system has the n cylindrical lenses corresponding to the n laser oscillators respectively and (n+1)/2 cylindrical lenses corresponding to the n cylindrical lenses. When five or more beam spots are overlapped, it is desirable that the fifth and subsequent laser beams are emitted from the side of the rear surface of a substrate in consideration of a position of an optical system, interference, and the like. Moreover, the substrate needs to be translucent. If either a plane including a shorter side or the one including a longer side when the plane is considered perpendicular to a plane to be irradiated and a shape of each beam spot is considered a rectangle is defined as an incidence plane, it is desirable that an incidence angle θ of the laser beam satisfies the inequality of θ≧arctan (W/2d). As for the inequality, “W” is a length of the longer side or the shorter side included in the incidence plane and “d” is a thickness of a light-transmitting substrate to the laser beam, which is placed on the plane to be irradiated. When a track of the laser beam is not on the incidence plane, an incidence angle of the track of the laser beam projected to the incidence plane is defined as θ. In the case where the laser beam enters at the incidence angle θ, it is possible to perform uniform irradiation of the laser beam without interference of reflected light from a surface of the substrate with reflected light from a rear surface of the substrate. In the above discussion, a refractive index of the substrate is considered 1. Practically, the substrate often has a refractive index of approximately 1.5. Considering the value, a larger value than an angle calculated in accordance with the above discussion is obtained. However, since energy at both ends in a longitudinal direction of a beam spot is attenuated, the interference has a small influence on both ends and the effect of attenuating the interference can sufficiently be obtained with the above-calculated value. In addition, an optical system in a laser irradiation apparatus of the present invention is not limited to the structure described in this embodiment. [Embodiment 6] In this embodiment, a shape of a beam spot obtained by combining a plurality of laser beams is described. FIG. 17A shows an example of a shape of a beam spot of a laser beam oscillated from each of plural laser oscillators on an object to be treated. A beam spot shown in FIG. 17A has an elliptical shape. Note that a shape of a beam spot of a laser beam oscillated from a laser oscillator is not limited to an ellipse in this embodiment. A shape of a beam spot depends on the kind of a laser, and a shape thereof can be changed through an optical system. For example, a shape of a laser beam emitted from a laser oscillator when using a XeCl excimer laser (wavelength 308 nm, pulse width 30 ns) L3308 manufactured by Lambda Physik Co., Ltd. is a rectangle having a size of 10 mm×30 mm (both are half width in a beam profile). In addition, a shape of an emitted laser beam when using a YAG laser having a cylindrical rod is circular and that of an emitted laser beam when using a YAG laser having a slab rod is rectangular. The laser beam can also be shaped into a laser beam having a desired size by further shaping it through an optical system. FIG. 17B shows energy density distribution of a laser beam in a Y direction of a major axis of the beam spot shown in FIG. 17A. The beam spot shown in FIG. 17A corresponds to a region satisfying energy density that is 1/e2 of a peak value of the energy density in FIG. 17B. Energy density distribution of a laser beam whose beam spot is elliptical becomes higher toward a center O of the ellipse. Next, FIG. 17C shows a shape of a beam spot when laser beams having the beam spot shown in FIG. 17A are combined. FIG. 17C shows the case where four beam spots of laser beams are overlapped to form one linear beam spot; however, the number of beam spots to be overlapped is not limited thereto. As shown in FIG. 17C, beam spots of each laser beam are combined to form one beam spot in such a way that major axes of each ellipse beam matches each other and beam spots are partially overlapped one another. Note that a straight line obtained by connecting centers O of each elliptical beam spot is defined as a central axis of a beam spot. FIG. 17D shows energy density distribution of laser beams in a Y direction of a central axis of the combined beam spots shown in FIG. 17C. The beam spot shown in FIG. 17C corresponds to a region satisfying energy density that is 1/e2 of a peak value of the energy density in FIG. 17B. The energy density is added in a portion in which each beam spot before being combined overlaps. For example, when energy density E1 and energy density E2 of an overlapped beam as shown are added, the added value is almost equal to a peak value E3 of the energy density of the beam. Thus, the energy density is made flat among centers O of each ellipse. It is ideal that the value added with E1 and E2 becomes equal to E3. However, it is not practically always equal. A designer can appropriately determine a margin of a gap between the value added with E1 and E2 and the value E3. When a beam spot is singularly employed as shown in FIG. 17A, the beam spot has Gaussian energy distribution. Therefore, it is difficult to irradiate an entire region in which an active layer is formed within a semiconductor film with a laser beam having uniform energy density. However, as FIG. 17D indicates, a region having uniform energy density can be enlarged by employing a plurality of laser beams to be overlapped and to compensate a portion having low energy density each other, compared to singularly employing a plurality of laser beams without overlapping. Accordingly, constraints on a layout of an active layer can be reduced, and crystallinity of a semiconductor film can efficiently be improved. [Embodiment 7] A specific structure of a semiconductor device of the present invention is described with reference to FIG. 19, giving a cellular phone that is one of electronic devices using a semiconductor device as an example. A cellular phone shown in FIG. 19, a signal line driver circuit 1807, a scanning line driver circuit 1806, a controller 1801, a CPU 1802, and a memory 1811 are mounted on a substrate 1800 over which a pixel portion 1805 is formed as a single thin film chip or a plurality of thin film chips. In addition, a power supply circuit 1803, an audio processing circuit 1829, and a transmitter-receiver circuit 1831 which are provided over a printed wiring board, furthermore, elements such as a resistor element, a buffer element, and a capacitor element are mounted through a connector such as an FPC. In this embodiment, a VRAM 1832, a DRAM 1825, a flash memory 1826, and the like are included in a memory 1811. Data of an image to be displayed in a panel are stored in the VRAM 1832; image data or audio data are stored in the DRAM 1825; and various kinds of programs are stored in the flash memory. In the power supply circuit 1803, supply voltage for the signal line driver circuit 1807, the scanning line driver circuit 1806, the controller 1801, the CPU 1802, the audio processing circuit 1829, the memory 1811, and the transmitter-receiver circuit 1804 is generated. In some cases, a power source is provided for the power supply circuit 1803 depending on the panel specification. The CPU 1802 includes a control signal generating circuit 1820, a decoder 1821, a register 1822, an operation circuit 1823, a RAM 1824, an interface 1835 for the CPU, and the like. Various kinds of signals inputted to the CPU 1802 through the interface 1835 are once stored in the register 1822, and then, are inputted to the operation circuit 1823, the decoder 1821, and the like. In the operation circuit 1823, an operation is performed in accordance with the inputted signal, and a place to which various instructions are sent is designated. On the other hand, the signal inputted to the decoder 1821 is decoded, and is inputted to the control signal generating circuit 1820. A signal including various instructions is generated in the control signal generating circuit 1820 based on the inputted signal, and is sent to the place designated by the operation circuit 1823, specifically, to the memory 1811, the transmitter-receiver circuit 1831, the audio processing circuit 1829, the controller 1801, or the like. The memory 1811, the transmitter-receiver circuit 1831, the audio processing circuit 1829, and the controller 1801 each operate according to each of received instructions. Each operation is briefly described hereinafter. A signal inputted from a keyboard 1840 is transmitted to the CPU 1802 through the interface 1809. In the control signal generating circuit 1820, the image data stored in the VRAM 1832 is converted to a predetermined format in accordance with the signal transmitted from a keyboard 1840 and is sent to the controller 1801. A signal including the image data sent from the CPU 1802 is data-processed in accordance with the panel specification in the controller 1801, and is supplied to the signal line driver circuit 1807 and the scanning line driver circuit 1806. In addition, a Hsync signal, a Vsync signal, a clock signal CLK, and a volts alternating current (AC Cont) are generated in the controller 1801 in accordance with a supply voltage inputted from the power supply circuit 1803 or various signals inputted from the CPU, and are supplied to the signal line driver circuit 1807 and the scanning line driver circuit 1806. In the transmitter-receiver circuit 1831, a signal that is transmitted and received as an electric wave is processed in an antenna 1833, and specifically, a high frequency circuit such as an isolator, a band pass filter, a VCO (Voltage Controlled Oscillator), an LPF (Low Pass Filter), a coupler, and a balun is included. A signal including audio information among signals transmitted and received in the transmitter-receiver circuit 1831 is transmitted to the audio processing circuit 1829 by an instruction of the CPU 1802. A signal including audio information sent by the instruction of the CPU 1802 is demodulated into an audio signal in the audio processing circuit 1829, and is sent to a speaker 1828. An audio signal send from a microphone 1827 is modulated in the audio processing circuit 1829, and is sent to the transmitter-receiver circuit 1831 by the instruction of the CPU 1802. In this embodiment, the controller 1801, the CPU 1802, and the memory 1811 are formed of thin film chips; however, the present invention is not limited thereto. The power supply circuit 1803 and the audio processing circuit 1829 may be formed of a thin film chip. According to the present invention, anything but a high frequency circuit such as an isolator, a band pass filter, a VCO (Voltage Controlled Oscillator), an LPF (Low Pass Filter), a coupler, or a balun can be formed in a thin film chip and be mounted on a substrate over which a pixel portion is formed. [Embodiment 8] A semiconductor device of the present invention can be used for a display portion of various electronic devices or other circuits for signal processing. Examples of electronic devices using the present invention are as follows: a video camera; a digital camera; a goggle type display (head mounted display); a navigation system; an audio reproducing device (a car audio, an audio component, or the like); a laptop personal computer; a game machine; a personal digital assistant (a mobile computer, a cellular phone, a portable game machine, an electronic book, or the like); an image reproducing device including a recording medium (specifically, a device capable of processing data in a recording medium such as a Digital Versatile Disk (DVD) and having a display that can display the image of the data), and the like. Practical examples of these electronic devices are shown in FIGS. 20A to 20F. FIG. 20A shows a portable digital assistant, which includes a main body 2001, a display portion 2002, operation keys 2003, a modem 2004, and the like. FIG. 20A shows a personal digital assistant in which the modem 2004 is removable; however, a modem may be incorporated in the main body 2001. A semiconductor device of the present invention can be used for the display portion 2002 or other circuits for signal processing. FIG. 20B shows a cellular phone, which includes a main body 2101, a display portion 2102, an audio input portion 2103, an audio output portion 2104, operation keys 2105, an external connection port 2106, an antenna 2107, and the like. If the display portion 2102 displays white letters on black background, a cellular phone consumes less power. A semiconductor device of the present invention can be used for the display portion 2102 or other circuits for signal processing. FIG. 20C shows an electronic card, which includes a main body 2201, a display portion 2202, a connection terminal 2203, and the like. A semiconductor device of the present invention can be used for the display portion 2202 or other circuits for signal processing. FIG. 20C shows a contact-type electronic card; however, a semiconductor device of the present invention can be used for an electric card having both functions of a contact-type and a non-contact-type. FIG. 20D shows an electronic book, which includes a main body 2301, a display portion 2302, operation keys 2303, and the like. In addition, a modem may be incorporated in the main body 2301. A semiconductor device of the present invention can be used for the display portion 2302 or other circuits for signal processing. FIG. 20E shows a sheet-shaped personal computer, which includes a main body 2401, a display portion 2402, a keyboard 2403, a touch pad 2404, an external connection port 2405, a plug for power supply 2406, and the like. A semiconductor device of the present invention can be used for the display portion 2402 or other circuits for signal processing. FIG. 20F shows a display device, which includes a chassis 2501, a supporting section 2502, a display portion 2503, a speaker portion 2504, a video input terminal 2505, and the like. A semiconductor device of the present invention can be used for the display portion 2503 or other circuits for signal processing. The display device includes all display devices for displaying information, including ones for personal computers, for TV broadcasting reception, and for advertisement. As described above, the applicable range of the present invention is so wide that the invention can be applied to electronic devices or other circuits for signal processing of various fields. This application is based on Japanese Patent Application serial no. 2003-277966 and 2003-277997 both filed in Japan Patent Office on Jul. 23 in 2003, the contents of which are hereby incorporated by reference. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a method for manufacturing a transistor, specifically a thin film transistor, having an LDD region, and further relates to a semiconductor device using the manufacturing method. 2. Related Art A semiconductor display device formed by using an inexpensive glass substrate cannot easily be miniaturized since a peripheral area (frame area) of a pixel portion required for mounting occupies more area in a substrate as resolution becomes higher. Thus, it is considered that there is a limitation on a method for mounting an integrated circuit formed by using a single crystalline silicon wafer on a glass substrate. Therefore, a technique for integrally forming an integrated circuit including a driver circuit over a glass substrate provided with a pixel portion, that is referred to as System On Panel, is now focused on. However, an integrated circuit formed over a glass substrate has lower degree of integration than that of an integrated circuit formed over a single crystalline silicon wafer. Therefore, it is an important object to miniaturize a semiconductor element on practical application. According to miniaturization of a semiconductor element, an integrated circuit formed over a glass substrate can highly be integrated, thereby promoting miniaturization, weight reduction, further, low power consumption, and speedup of a semiconductor display device. In addition, according to miniaturization of a semiconductor element as well as an integrated circuit, high definition can be realized also in a pixel portion. A semiconductor display device provided with a thin film transistor (TFT) using an amorphous semiconductor film in a pixel portion has the advantage of having high productivity and low cost. However, the TFT using an amorphous semiconductor film has the disadvantage of having low mobility. Therefore, it is considered that a thin film transistor using an amorphous semiconductor film is unsuitable for a driver circuit that required high-speed operation such as a scanning line driver circuit for selecting a pixel or a signal line driver circuit for supplying a video signal to the selected pixel. Thus, a mode of manufacturing an IC chip in which a driver circuit is included by using a single crystalline silicon wafer and of mounting the IC chip on the periphery of a pixel portion by TAB (Tape Automated bonding) or COG (Chip on Glass) is generally adopted. However, a unit cost of a silicon wafer is higher than that of a glass substrate, and a silicon wafer is not suitable for providing an inexpensive IC chip. The advantage of a low cost that is a characteristic of a semiconductor display device using an amorphous semiconductor film cannot fully be utilized. The sizes of silicon wafers that are comparatively a lot on the market are approximately not more than 12 inches in diameter. Although more than 12 inches sized silicon wafers are also on the market, a cost per unit area further increases as its size increases. Consequently, costs have to be sacrificed in order to increase throughput by increasing the number of IC chips obtained from one substrate. Thus, a technique of forming a driver circuit over a glass substrate, dividing into strips, and mounting on a substrate over which a pixel portion is formed is disclosed in the following references (Reference 1: Japanese Patent Application Laid-Open No. 7-014880, and Reference 2: Japanese Patent Application Laid-Open No. 11-160734). As disclosed in References 1 and 2, an incidence rate of a defect in a contact portion of a terminal, caused by a difference of a thermal expansion coefficient can be decreased by using a substrate made of the same material as a substrate over which a pixel portion is formed (hereinafter, referred to as an element substrate), forming a driver circuit, and mounting on the element substrate. Accordingly, a yield can be increased. In addition, a cost of a semiconductor display device as a whole can be reduced by forming a driver circuit over a glass substrate. Meanwhile, a semiconductor display device cannot easily be miniaturized since a peripheral area (frame area) of a pixel portion required for mounting occupies more area in a substrate as resolution of a pixel portion becomes higher. Therefore, an IC chip mounted on a substrate over which a pixel portion is formed is preferably smaller. However, an integrated circuit formed over a glass substrate has lower degree of integration than that of an integrated circuit formed over a single crystalline silicon wafer. Therefore, on promoting miniaturization of a semiconductor display device and high integration of an integrated circuit, it is an important object to miniaturize a semiconductor element formed over a glass substrate. When an integrated circuit formed over a glass substrate can highly be integrated according to miniaturization of a semiconductor element, miniaturization, weight reduction, further, low power consumption, and speedup of a semiconductor display device can be advanced. However, miniaturization of a TFT that is one of semiconductor elements involves a problem of decline in reliability due to a hot carrier effect. Therefore, an LDD (Lightly Doped Drain) structure is adopted as a means of controlling a hot carrier effect. The LDD structure is a structure in which an LDD region having a lower impurity concentration than that of a source/drain region is provided between the source/drain region and a channel formation region. Particularly, it is known that in the case of having a structure in which an LDD region is overlapped with a gate electrode with a gate insulating film therebetween (GOLD structure, Gate Overlapped Lightly Doped Drain structure), a hot carrier effect can efficiently be prevented by relaxation of a high electric field in the vicinity of a drain and reliability can be improved. In this specification, a region in which an LDD region is overlapped with a gate electrode with a gate insulating film therebetween is referred to as an Lov region and a region in which an LDD region is not overlapped with a gate electrode is referred to as an Loff region. It is disclosed in the following reference that deterioration of a transistor can be prevented by employing a GOLD structure (Reference 3: Japanese Patent Application Laid-Open No. 8-153875). A TFT having an Loff region tends to be able to reduce more off current than a TFT having an Lov region. Therefore, a TFT having an Loff region is suitably used for a switching element of a pixel in which reduction of an off current is regarded as more important than high-speed drive. Meanwhile, a TFT having an Lov region can be driven at higher speed than a TFT having an Loff region. Specifically, switching can be performed at higher speed. A TFT having an Lov region is suitably used for a driver circuit since operating frequency is higher than that of a pixel portion and high-speed drive is regarded as more important than reduction of an off current. It is preferable that a TFT having an Loff region and a TFT having an Lov region are appropriately used according to characteristics required for a circuit element. Several methods have been proposed for manufacturing a TFT having an Lov region, and one of them is to obliquely implant ions using a gate electrode as a mask. According to the above method, a dopant (impurity) can be added by an ion implantation method to a region overlapped with a gate electrode with a gate insulating film therebetween, without using a resist mask and with the number of steps reduced. However, in order to form an Lov region on both a source region side and a drain region side, it is necessary to perform ion implantation twice from a different implantation direction. This can be a factor of preventing a throughput in a step of ion implantation from improving. In addition, there is a method (tilt rotation) for obliquely and uniformly implanting ions by rotating a substrate; however, according to this method, rotation of a substrate need to precisely be controlled and a large-scale apparatus for performing ion implantation is required. Particularly, the method is not suitable for a large substrate, and becomes a factor in preventing throughput from improving. In addition, according to the above method, there is a problem that a TFT having an Lov region and a TFT having an Loff region cannot separately be formed over one substrate. According to the above method, a TFT having an Lov region and a TFT having an Loff region cannot separately be formed over one substrate in the case of integrating a pixel portion and a driver circuit by System On Panel. In addition, such a TFT without an LDD region that a source region and a drain region are in contact with a channel formation region and a TFT having an Lov region cannot separately be formed over one substrate. A TFT having an Lov region and a TFT having an Loff region can separately be formed over one substrate by separately implanting a dopant using a resist mask. However, the number of resist masks and steps cannot be reduced, which becomes a factor of increasing a manufacturing cost. When a transistor having an offset gate structure, a transistor in which a source region and a drain region are in contact with a channel formation region, and the like as well as a TFT having an Loff region are intended to separately be formed over one substrate, the number of resist masks and steps cannot be reduced, which becomes a factor of increasing a manufacturing cost. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the above problems, the present invention relates to a method for manufacturing a semiconductor device in which a transistor having an Lov region can separately be formed over a substrate provided with a transistor having an Loff region, a transistor having an offset gate structure, and a transistor in which a source region and a drain region are in contact with a channel formation region without providing a resist mask for forming an Lov region and throughput in a step of ion implantation can be improved. Further, the present invention relates to a semiconductor device that can reduce a cost per panel. Furthermore, the present invention relates to a semiconductor device which can reduce a cost per panel, using a chip in which an integrated circuit is formed of a thin semiconductor film (hereinafter, referred to as a thin film chip). The inventors of the present invention think that it is better to change a position of an Lov region provided in an active layer of a transistor according to a dopant implantation direction than according to change the dopant implantation direction to a position of an Lov region. In other words, ion implantation is regarded as a fixed implantation in which an implantation direction is set to one direction, and a positional relationship among an Lov region, a channel formation region, and a gate electrode functioning as a mask in ion implantation is determined according to the implantation direction. Note that an implantation direction in this specification means a direction that a dopant is implanted from an ion source. Specifically, an implantation direction is set to such one direction that a dopant obliquely intersects with a surface of an active layer, and an edge portion of a gate electrode overlapping an active layer is directed to the implantation direction side. Namely, a gate electrode and an active layer are disposed so that an exposed region of the active layer but a region overlapped with the gate electrode is situated closer to an implantation direction side than the region overlapped with the gate electrode. According to the above structure, an Lov region can be formed on both a source region side and a drain region side by ion implantation from one implantation direction. Therefore, in all transistors having the same conductivity and having an Lov region, the Lov region is disposed closer to a dopant implantation direction side than a channel formation region. In the case of performing ion implantation to form an Lov region, in a transistor having an Loff region, a positional relationship among an active layer, a gate electrode, and an Loff region is determined according to an implantation direction so that an impurity is added only to a region serving as a source region and a drain region. Specifically, a region serving as an Loff region and a channel formation region is covered with a resist mask, and a region overlapped with the resist mask and an exposed region of the active layer but the region are disposed to be in contact with each other along the implantation direction. In other words, an edge portion of the resist mask overlapping the active layer is disposed to be in contact with each other along the implantation direction. According to the above structure, a transistor having an Lov region and a transistor having an Loff region can separately be formed over one substrate. In the case of performing ion implantation to form an Lov region, in a transistor without an LDD region, in which a source region and a drain region are in contact with a channel formation region, a positional relationship among an active layer, a gate electrode, and an LDD region is determined according to an implantation direction so that an impurity is added only to a region serving as a source region and a drain region. Specifically, a region overlapped with the gate electrode and an exposed region of the active layer but the region are disposed to be in contact with each other along the implantation direction. In other words, an edge portion of the gate electrode overlapping the active layer is disposed to be along the implantation direction. According to the above structure, a transistor having an Lov region and a transistor in which a source region and a drain region are in contact with a channel formation region can separately be formed over one substrate. In the case of performing ion implantation to form an Lov region, in a transistor having an offset region, a positional relationship among an active layer, a gate electrode, and an offset region is determined according to an implantation direction so that an impurity is added only to a region serving as a source region and a drain region and the offset region is formed. Specifically, the gate electrode and the active layer are disposed so that an exposed region of the active layer is disposed on an opposite side from an implantation direction with respect to the gate electrode. In other words, an edge portion of the gate electrode overlapping the active layer is disposed on an opposite side of the implantation direction. According to the above structure, a transistor having an Lov region and a transistor having an offset region can separately be formed over one substrate. In addition to the above structure, a continuous wave laser may be used for crystallization of a semiconductor film. A semiconductor film crystallized by using only a pulsed laser beam is formed of a cluster of a plurality of crystal grains, in which the position and the size thereof are at random. Compared to the inside of crystal grains, thousands of recombination centers or trapping centers due to an amorphous structure or a crystal defect exist at the interfaces of crystal grains (crystal grain boundary). There is a problem that the potential of a crystal grain boundary is increased when carriers are trapped in the trapping centers, and is resulted in a barrier against carriers, so that the current transporting characteristics of carriers decrease. On the other hand, in the case of a continuous wave laser beam, a cluster of crystal grains made of single crystals elongating along a scanning direction can be formed by irradiating a semiconductor film while scanning the semiconductor film with an irradiation region (beam spot) of a laser beam in one direction to continuously grow crystals in the scanning direction. Therefore, mobility of a TFT used for a thin film chip can be improved by crystallizing a semiconductor film using a continuous wave laser. A semiconductor device included in the category of the present invention includes all kinds of semiconductor devices using a transistor, such as a microprocessor, an image processing circuit, and a semiconductor display device. In addition, a thin film chip itself is included in the category of the semiconductor device of the present invention. The semiconductor display device includes a liquid crystal display device, a light emitting device having a light emitting element in each pixel, typified by an organic light-emitting element (OLED), a DMD (Digital Micromirror Device), a PDP (Plasma Display Panel), an FED (Field Emission Display), and other display devices having a circuit element using a semiconductor film in a driver circuit in its category. A transistor in which an Lov region can be formed by using a manufacturing method of the present invention is not limited to a TFT using polycrystalline silicon, microcrystalline silicon (semi-amorphous silicon (SAS)), or amorphous silicon. The transistor may be a transistor formed by using single crystalline silicon, and it may be a transistor using SOI. Alternatively, it may be a transistor using an organic semiconductor, and it may be a transistor using a carbon nanotube. In addition, a transistor used for a semiconductor device of the present invention may have a single gate structure, a double gate structure, or a multi gate structure having three or more gate electrodes. According to the above structures of the present invention, a transistor having an Lov region can separately be formed over a substrate provided with a transistor having an Loff region, a transistor in which a source region and a drain region are in contact with a channel formation region, a transistor having an offset region, and the like without providing a resist mask for forming an Lov region. Consequently, the number of resist masks and steps can be reduced, and a manufacturing cost can be reduced. In addition, throughput in a step of ion implantation can be improved. In the present invention, a semiconductor device may be formed by mounting an integrated circuit using the above manufacturing method as a thin film chip on a substrate provided with a pixel portion or other integrated circuits. In addition to the above manufacturing method, the present invention includes the above thin film chip using the above manufacturing method and a semiconductor device on which the thin film chip is mounted in its category. Since a cost per chip of a thin film chip of the present invention can be reduced, a cost of a semiconductor device itself having the thin film chip can also be reduced. These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description along with the accompanied drawings. | 20040714 | 20080429 | 20050127 | 72911.0 | 0 | TRAN, MINH LOAN | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,327 | ACCEPTED | Apparatus for conveying sheets in a printing press | An apparatus for conveying sheets in a printing press makes reliable sheet guiding possible with a low outlay on material and at low cost and includes an apparatus for conveying sheets in a printing press having at least one conveyor element for a sheet along a conveying path and at least one guide element for the sheet in the conveying direction, at least one elongate spring element being provided as a guide element. | 1. An apparatus for conveying sheets in a printing press, comprising: at least one conveyor element for conveying a sheet along a conveying path in a conveying direction; and at least one guide element for guiding the sheet in said conveying direction, said at least one guide element being at least one elongate spring element. 2. The apparatus according to claim 1, wherein said at least one spring element is at least one helical spring. 3. The apparatus according to claim 2, wherein said at least one helical spring has windings wound from round wire. 4. The apparatus according to claim 2, wherein said at least one spring element is a plurality of helical tension springs disposed parallel to one another. 5. The apparatus according to claim 4, further comprising a common holder, said helical tension springs each having ends respectively fastened to said common holder. 6. The apparatus according to claim 2, further comprising: a frame connected to at least one of said at least one conveyor element and said least one helical spring, said frame having mandrels fixed thereto; and said least one helical spring having ends guided in said mandrels. 7. The apparatus according to claim 2, wherein: said at least one guide element has braking modules disposed transversely with respect to said conveying direction; and said at least one helical spring is a plurality of helical springs disposed between said braking modules. 8. The apparatus according to claim 7, wherein: said helical springs have ends; said braking modules have positioning regions; said ends move, with said braking modules, transversely with respect to said conveying direction; and said helical springs are tensioned to substantially maintain a stretched position in a positioning region of said braking modules. 9. The apparatus according to claim 7, wherein: said helical springs have ends; said braking modules have positioning regions; said ends move with said braking modules; and said helical springs are tensioned to substantially maintain a stretched position in a positioning region of said braking modules. 10. The apparatus according to claim 2, wherein: said at least one conveyor element is two conveyor elements movably disposed toward one another; and said at least one helical spring is a plurality of helical springs disposed between said two conveyor elements for bridging a format in said conveying direction. 11. An apparatus for conveying sheets in a printing press, comprising: at least one conveyor element for conveying a sheet along a conveying path in a conveying direction; a holder; and a guide element having: braking modules disposed transversely with respect to said conveying direction; tension springs for guiding the sheet in said conveying direction, said springs: being disposed parallel to one another; and each having ends respectively fastened to said holder; a frame connected to at least one of said at least one conveyor element and said springs, said frame having mandrels; and said springs being disposed between said braking modules and having ends guided in said mandrels. 12. In a printing press, an apparatus for conveying sheets comprising: at least one conveyor element for conveying a sheet along a conveying path in a conveying direction; and at least one guide element for guiding the sheet in said conveying direction, said at least one guide element being at least one elongate spring element. 13. In a printing press, an apparatus for conveying sheets comprising: at least one conveyor element for conveying a sheet along a conveying path in a conveying direction; a holder; and a guide element having: braking modules disposed transversely with respect to said conveying direction; tension springs for guiding the sheet in said conveying direction, said springs: being disposed parallel to one another; and each having ends respectively fastened to said holder; a frame connected to at least one of said at least one conveyor element and said springs, said frame having mandrels; and said springs being disposed between said braking modules and having ends guided in said mandrels. | BACKGROUND OF THE INVENTION Field of the Invention The invention relates to an apparatus for conveying sheets in a printing press having at least one conveyor element for a sheet along a conveying path and at least one guide element for the sheet in the conveying direction. In printing presses, it is known to convey sheets from the last printing unit onto a stack, the leading edge of the sheets being held on grippers that are fastened on a circulating chain mechanism. Before a sheet is deposited onto the stack, its conveying speed is reduced using braking modules that have suction belts that are narrow with regard to the sheet width. Thin sheets tend to sag between the braking modules. The sagging impairs the formation of stacks and can cause the corners to be folded over. The braking modules can be adjusted laterally to adapt the position transversely with respect to the conveying direction to the sheet width. The spacing between the braking modules can be of varying size. Therefore, the width of support elements that are provided to reduce the sagging between the braking modules must be adjustable. German Published, Non-Prosecuted Patent Application DE 101 34 836 A1, corresponding to U.S. Pat. No. 6,557,468 to Kelm et al., describes a delivery for a sheet-fed printing press in which a plurality of braking devices are provided that can be adjusted transversely with respect to the sheet conveying direction. A sheet-guiding device including a belt of flexible material is disposed in the intermediate space between adjacent braking devices, it being possible to adapt the length of the belt transversely with respect to the conveying direction to the spacing of adjacent braking devices. Support of this type of a sheet using a roller blind is complicated in constructional terms because of the requirement for a roller blind tensioning mechanism and requires a large amount of installation space. In addition, the deflection and tensioning rollers used are sensitive to contamination, in particular, in deliveries in which the sheets are powdered to prevent smudging. Furthermore, guide plates or guide loops are known as support elements, in which no measures to adjust the support width is provided. Depending on requirements, guide plates of varying width or a varying number of guide loops are used. Furthermore, it is known to provide guide plates or guide loops whose support width can be adjusted and that lie in an overlapped manner or are configured to be telescopic. Such constructions are complicated and susceptible to contamination. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide an apparatus for conveying sheets in a printing press that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that that makes reliable sheet guiding possible with a low outlay on material and at low cost. With the foregoing and other objects in view, there is provided, in accordance with the invention, a apparatus for conveying sheets in a printing press, including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction and at least one guide element for guiding the sheet in the conveying direction, the at least one guide element being at least one elongate spring element. According to the invention, an elongate spring element is tensioned transversely or longitudinally with respect to the conveying direction as guide elements for a sheet. Helical springs whose ends are fastened to a holder are particularly suitable. To prevent back swing in the event of contact with a sheet, the ends of the helical springs can be guided in mandrels. The use of a plurality of helical springs in parallel next to one another results in virtually a support surface with punctiform contact of a sheet. Helical springs having a winding made from round wire are not sensitive to powder, are inexpensive and do not have any sharp edges that could scratch a sheet. The surfaces of the helical springs can have a special coating, over which a sheet can slide in a particularly gentle manner. The helical springs are compliant so that damping occurs if a sheet touches the helical springs abruptly. The invention can be used in machines that process, coat, inspect, or merely transport the sheet. Within the context of the invention, sheet is to be understood as meaning individual sheets, a plurality of collated sheets, or folded products. In accordance with another feature of the invention, at least one spring element is at least one helical spring. In accordance with a further feature of the invention, the at least one-helical spring has windings wound from round wire. In accordance with an added feature of the invention, the at least one spring element is a plurality of helical tension springs disposed parallel to one another. In accordance with an additional feature of the invention, there is provided a common holder, the helical tension springs each having ends respectively fastened to the common holder. In accordance with yet another feature of the invention, there is provided a frame connected to at least one of the at least one conveyor element and the least one helical spring, the frame having mandrels fixed thereto and the least one helical spring having ends guided in the mandrels. In accordance with yet a further feature of the invention, the at least one guide element has braking modules disposed transversely with respect to the conveying direction and the at least one helical spring is a plurality of helical springs disposed between the braking modules. In accordance with yet an added feature of the invention, the helical springs have ends, the braking modules have positioning regions, the ends move, with the braking modules, transversely with respect to the conveying direction, and the helical springs are tensioned to substantially maintain a stretched position in a positioning region of the braking modules. In accordance with yet an additional feature of the invention, the helical springs have ends, the braking modules have positioning regions, the ends move with the braking modules, and the helical springs are tensioned to substantially maintain a stretched position in a positioning region of the braking modules. In accordance with again another feature of the invention, at least one conveyor element is two conveyor elements movably disposed toward one another and the at least one helical spring is a plurality of helical springs disposed between the two conveyor elements for bridging a format in the conveying direction. With the objects of the invention in view, there is also provided an apparatus for conveying sheets in a printing press, including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction, a holder, and a guide element having braking modules disposed transversely with respect to the conveying direction, tension springs for guiding the sheet in the conveying direction, the springs being disposed parallel to one another, each having ends respectively fastened to the holder, a frame connected to at least one of the at least one conveyor element and the springs, the frame having mandrels, the springs being disposed between the braking modules and having ends guided in the mandrels. With the objects of the invention in view, in a printing press, there is also provided an apparatus for conveying sheets including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction and at least one guide element for guiding the sheet in the conveying direction, the at least one guide element being at least one elongate spring element. With the objects of the invention in view, there is also provided a In a printing press, an apparatus for conveying sheets including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction, a holder, and a guide element having braking modules disposed transversely with respect to the conveying direction, tension springs for guiding the sheet in the conveying direction, the springs being disposed parallel to one another and each having ends respectively fastened to the holder, a frame connected to at least one of the at least one conveyor element and the springs, the frame having mandrels, and the springs being disposed between the braking modules and having ends guided in the mandrels. Other features that are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in an apparatus for conveying sheets in a printing press, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, cross-sectional diagrammatic view of a delivery of a printing press according to the invention having a braking station for sheets; FIG. 2 is a fragmentary, perspective view of a braking station according to the invention having helical springs as support elements for sheets; FIG. 3A is a plan and partially hidden view of a braking station according to the invention with a suspension of helical springs on holders having mandrels; FIG. 3B is a cross-sectional view from a side of the suspension of the helical springs of FIG. 3A; FIG. 3C is a cross-sectional view from an end of the suspension of helical springs of FIG. 3A; and FIG. 4 is a fragmentary, perspective view of a braking station according to the invention as measures to bridge the format. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a delivery 1 connected behind (downstream of) a printing unit 2. The printing unit 2 includes an impression cylinder 2.1, a blanket cylinder 2.2, a single revolution transfer drum 2.3, and a half-revolution transfer drum 2.4. Sheets 3 are transported individually one after another from the printing unit 2 to a stacking device 5 by a chain conveyor 4. The stacking device 5 has a platform 5.1 and lifting chains 5.2; furthermore, it has a leading edge stop 5.3 and a trailing edge stop 5.4. Inter alia, the chain conveyor 4 includes conveyor chains 4.1, gripper bars 4.2, drive sprockets 4.3, and deflection sprockets 4.4. A hollow sheet guiding apparatus 6 is provided in the rising region of the chain delivery 1. It has two inlet stubs 6.1, 6.2 and an outlet stub 6.3 for supplying and discharging blown air. On its side that faces the sheet 3, it is provided with blowing nozzles that are not shown in FIG. 1. Furthermore, the delivery 1 includes a braking device 7, which will be described in yet more detail in the following text. The braking station 7 shown in FIG. 2 includes five suction belt modules 7.1 to 7.5 in a parallel configuration with respect to the conveying direction 8 of the sheets 3. The suction belt modules 7.1 to 7.5 can be positioned transversely with respect to the conveying direction 8 individually onto print-free regions of the sheet 3. For such a purpose, the suction belt modules 7.1 to 7.5 are mounted on a guide rod 9 that is fastened in a frame 10.1, 10.2. Stepping motors 11.1 to 11.5 that are coupled to the suction belt modules 7.1 to 7.5 are provided as positioning drives. Pinions 12 are disposed on the drive shafts of the stepping motors 11 in each case so as to rotate with the stepping motors 11, the pinions 12 engaging in a chain 13 whose ends are fastened in the frame 10.1, 10.2 and that is oriented parallel to the guide rod 9. The suction belt modules 7.1 to 7.5 include suction belts 14 that are guided over deflection rollers. The suction belts 14 are driven synchronously, in that in each case one deflection roller is coupled to a shaft 15 that is rotatably mounted in the frame 10.1, 10.2. The shaft 15 is coupled to a gear mechanism 16 and a motor 17. Below the suction belts 14 there are suction ducts that are connected to a vacuum source through lines 18. The lines 18 are movably routed in a tube duct 19. The trailing edge stops 5.4 are fastened to the suction belt modules 7. The entire braking station 7 described in FIG. 2, including the suction belt modules 7.1 to 7.5, can be positioned in the conveying direction 8 in the deliver 11 for adaptation to various length formats of the sheets 3. The suction belts 14 have vacuum openings 20. When a sheet 3 is guided over the suction belts 14 using a gripper bar 4.2, it is held on the suction belts 14 by the effect of vacuum. Thin sheets 3, in particular, sag between the suction belt modules 7.1 to 7.5. Three helical tension springs 21 are disposed in each case between adjacent suction belt modules 7.1 to 7.5 to support sagging sheets 3. The helical tension springs 21 lie in each case parallel to one another in a plane 22 below a supporting plane 23 for the sheets 3 on the suction belts 14. The three views in FIGS. 3A to 3C show, in greater detail, how the helical tension springs 21 are suspended on both sides of the suction belt module 7.2. A suction belt module 7.1 to 7.5 includes a basic body 24 in which two deflection rollers 25, 26 for a suction belt 14 are mounted. The deflection roller 25 is driven through the shaft 15. The ends of three helical tension springs 21 are guided through mandrels 27 and suspended on the mandrels 27 with hook-shaped eyes 28. The mandrels 27 sit on holders 29. A threaded bolt 30 that projects out of the basic body 24 on both sides is provided to fasten the holders 29. The holders 29 are screwed to the threaded bolt 30 using knurled nuts 31, 32. Locating pins 33, 34 secure the rotary position of the holders 29 on the threaded bolt 30 and the spacing d of the support surface of the helical tension springs 21 from the suction belt plane 23. The spacing d simultaneously defines the maximum sagging of a sheet 3. FIG. 4 shows an exemplary embodiment in which tension springs 35 are provided for bridging the format. A multiplicity of parallel tension springs 35 is disposed across the width of the sheets 3 in the conveying direction 8. One end of the tension springs 35 is fastened to the sheet-guiding device 6 and the other end is fastened to a planar guide element 36. The guide element 36 is coupled to the braking device 7. When, for adjustment to a new web length format, the braking device 7 and the trailing edge stop 5.4 are positioned horizontally in the conveying direction 8, as specified by the double arrow 37, the guide element 36 and the tension springs 35 fastened to it are carried along with them. The tension springs 35 are extended in the conveying direction 8 to a greater or lesser degree and form a supporting surface for the sheets 3 in the region between the sheet guiding apparatus 6 and the guide element 36. It is possible to fasten the ends of the tension springs 35 directly to the braking device 7, leaving out the guide element 36. This application claims the priority, under 35 U.S.C. § 119, of German patent application No. 103 33 753.9, filed Jul. 24, 2003; the entire disclosure of the prior application is herewith incorporated by reference. | <SOH> BACKGROUND OF THE INVENTION <EOH>Field of the Invention The invention relates to an apparatus for conveying sheets in a printing press having at least one conveyor element for a sheet along a conveying path and at least one guide element for the sheet in the conveying direction. In printing presses, it is known to convey sheets from the last printing unit onto a stack, the leading edge of the sheets being held on grippers that are fastened on a circulating chain mechanism. Before a sheet is deposited onto the stack, its conveying speed is reduced using braking modules that have suction belts that are narrow with regard to the sheet width. Thin sheets tend to sag between the braking modules. The sagging impairs the formation of stacks and can cause the corners to be folded over. The braking modules can be adjusted laterally to adapt the position transversely with respect to the conveying direction to the sheet width. The spacing between the braking modules can be of varying size. Therefore, the width of support elements that are provided to reduce the sagging between the braking modules must be adjustable. German Published, Non-Prosecuted Patent Application DE 101 34 836 A1, corresponding to U.S. Pat. No. 6,557,468 to Kelm et al., describes a delivery for a sheet-fed printing press in which a plurality of braking devices are provided that can be adjusted transversely with respect to the sheet conveying direction. A sheet-guiding device including a belt of flexible material is disposed in the intermediate space between adjacent braking devices, it being possible to adapt the length of the belt transversely with respect to the conveying direction to the spacing of adjacent braking devices. Support of this type of a sheet using a roller blind is complicated in constructional terms because of the requirement for a roller blind tensioning mechanism and requires a large amount of installation space. In addition, the deflection and tensioning rollers used are sensitive to contamination, in particular, in deliveries in which the sheets are powdered to prevent smudging. Furthermore, guide plates or guide loops are known as support elements, in which no measures to adjust the support width is provided. Depending on requirements, guide plates of varying width or a varying number of guide loops are used. Furthermore, it is known to provide guide plates or guide loops whose support width can be adjusted and that lie in an overlapped manner or are configured to be telescopic. Such constructions are complicated and susceptible to contamination. | <SOH> SUMMARY OF THE INVENTION <EOH>It is accordingly an object of the invention to provide an apparatus for conveying sheets in a printing press that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that that makes reliable sheet guiding possible with a low outlay on material and at low cost. With the foregoing and other objects in view, there is provided, in accordance with the invention, a apparatus for conveying sheets in a printing press, including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction and at least one guide element for guiding the sheet in the conveying direction, the at least one guide element being at least one elongate spring element. According to the invention, an elongate spring element is tensioned transversely or longitudinally with respect to the conveying direction as guide elements for a sheet. Helical springs whose ends are fastened to a holder are particularly suitable. To prevent back swing in the event of contact with a sheet, the ends of the helical springs can be guided in mandrels. The use of a plurality of helical springs in parallel next to one another results in virtually a support surface with punctiform contact of a sheet. Helical springs having a winding made from round wire are not sensitive to powder, are inexpensive and do not have any sharp edges that could scratch a sheet. The surfaces of the helical springs can have a special coating, over which a sheet can slide in a particularly gentle manner. The helical springs are compliant so that damping occurs if a sheet touches the helical springs abruptly. The invention can be used in machines that process, coat, inspect, or merely transport the sheet. Within the context of the invention, sheet is to be understood as meaning individual sheets, a plurality of collated sheets, or folded products. In accordance with another feature of the invention, at least one spring element is at least one helical spring. In accordance with a further feature of the invention, the at least one-helical spring has windings wound from round wire. In accordance with an added feature of the invention, the at least one spring element is a plurality of helical tension springs disposed parallel to one another. In accordance with an additional feature of the invention, there is provided a common holder, the helical tension springs each having ends respectively fastened to the common holder. In accordance with yet another feature of the invention, there is provided a frame connected to at least one of the at least one conveyor element and the least one helical spring, the frame having mandrels fixed thereto and the least one helical spring having ends guided in the mandrels. In accordance with yet a further feature of the invention, the at least one guide element has braking modules disposed transversely with respect to the conveying direction and the at least one helical spring is a plurality of helical springs disposed between the braking modules. In accordance with yet an added feature of the invention, the helical springs have ends, the braking modules have positioning regions, the ends move, with the braking modules, transversely with respect to the conveying direction, and the helical springs are tensioned to substantially maintain a stretched position in a positioning region of the braking modules. In accordance with yet an additional feature of the invention, the helical springs have ends, the braking modules have positioning regions, the ends move with the braking modules, and the helical springs are tensioned to substantially maintain a stretched position in a positioning region of the braking modules. In accordance with again another feature of the invention, at least one conveyor element is two conveyor elements movably disposed toward one another and the at least one helical spring is a plurality of helical springs disposed between the two conveyor elements for bridging a format in the conveying direction. With the objects of the invention in view, there is also provided an apparatus for conveying sheets in a printing press, including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction, a holder, and a guide element having braking modules disposed transversely with respect to the conveying direction, tension springs for guiding the sheet in the conveying direction, the springs being disposed parallel to one another, each having ends respectively fastened to the holder, a frame connected to at least one of the at least one conveyor element and the springs, the frame having mandrels, the springs being disposed between the braking modules and having ends guided in the mandrels. With the objects of the invention in view, in a printing press, there is also provided an apparatus for conveying sheets including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction and at least one guide element for guiding the sheet in the conveying direction, the at least one guide element being at least one elongate spring element. With the objects of the invention in view, there is also provided a In a printing press, an apparatus for conveying sheets including at least one conveyor element for conveying a sheet along a conveying path in a conveying direction, a holder, and a guide element having braking modules disposed transversely with respect to the conveying direction, tension springs for guiding the sheet in the conveying direction, the springs being disposed parallel to one another and each having ends respectively fastened to the holder, a frame connected to at least one of the at least one conveyor element and the springs, the frame having mandrels, and the springs being disposed between the braking modules and having ends guided in the mandrels. Other features that are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in an apparatus for conveying sheets in a printing press, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. | 20040713 | 20071002 | 20050217 | 67383.0 | 0 | MCCLAIN, GERALD | APPARATUS WITH SPRINGS FOR CONVEYING SHEETS IN A PRINTING PRESS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,468 | ACCEPTED | Vacuum regulating valve | A vacuum regulating valve which is simplified in structure and where the flow rate characteristic in evacuating a vacuum vessel is improved, comprises (i) a main valve 1A of a large size which has: a principal body 4 having two main ports 11, 12 connected to a vacuum vessel 7 and a vacuum pump 8, respectively, a valve seat 14 disposed in a fluid passage connecting the ports 11, 12, a valve element 15 seated on and separated from the valve seat 14, and a shaft 20 extending from the valve element 15; and a valve element operating unit 5 for operating the valve element 15 via the shaft 20, and (ii) a sub valve 2A of a small size similar in structure to the main valve 1A. The sub valve 2A is attached to an outer side surface of a casing 10 of the main valve 1A. | 1. A vacuum regulating valve comprising: a main valve which has a relatively large size and comprises: a casing which defines therein a valve chamber extending along an axis of the main valve, and which has: a first main port which is capable of communicating with the valve chamber through a communication opening and is connected to a vacuum vessel; and a second main port connected to a vacuum pump; a main valve seat formed at an outer periphery of the communication opening; a main valve element which is disposed in the valve chamber, and seated on and separated from the main valve element; a main valve stem extending in the valve chamber from the main valve element; and a main valve element operating unit which drives the main valve stem to move the main valve element onto and away from the main valve seat; and a sub valve which has a relatively small size, is attached to an external side surface of the casing of the main valve, and comprises: a bypass passage which extends from and outside the casing to bypass the main valve seat; a sub valve seat which is disposed in the bypass passage and has an opening area which is smaller than an opening area of the main valve seat; a sub valve element which is seated on and separated from the sub valve element; a sub valve stem extending from the sub valve element; and a sub valve element operating unit which drives the sub valve stem to move the sub valve element onto and away from the sub valve seat. 2. The vacuum regulating valve according to claim 1, wherein the casing has a first connecting hole and a second connecting hole which are formed through the thickness of the casing, and the bypass passage has two opposite ends, one of which serves as a first bypass port connected to the first main port through the first connecting hole, while the other of which serves as a second bypass port connected to the second main port through the second connecting hole. 3. The vacuum regulating valve according to claim 1 wherein the main valve element operating unit and the sub valve element operating unit are substantially identically constructed. 4. The vacuum regulating valve according to claim 1, wherein the main valve element operating unit comprises: a main piston attached to an end of the main valve stem; a main pressure chamber accommodating a fluid whose pressure acts on the main piston and is controlled to move the main valve element in a direction away from the main valve seat; and a main pilot port for therethrough supplying the main pressure chamber with a pilot fluid, while the sub valve element operating unit comprises: a sub piston attached to an end of the sub valve stem; a sub pressure chamber accommodating a fluid, whose pressure acts on the sub piston and is controlled to move the sub valve element in a direction away from the sub valve seat; and a sub pilot port for therethrough supplying the sub pressure chamber with a pilot fluid, and wherein the main valve further comprises a return spring which biases the main valve element toward the main valve seat, while the sub valve further comprises a return spring which biases the sub valve element toward the sub valve seat. 5. The vacuum regulating valve according to claim 4, wherein the main valve comprises a partition wall whose opposite sides respectively partially defines the valve chamber and the main pressure chamber and the return spring of the main valve is disposed between the partition wall and the main valve element, while the sub valve comprises a cylinder cover which covers a rear side of the sub piston toward which the sub piston is retracted when the sub valve element is separated from the sub valve seat and the return spring of the sub valve is disposed between the sub piston and the cylinder cover. 6. The vacuum regulating valve according to claim 4, wherein at least one of the main valve operating unit and the sub valve operating unit of the vacuum regulating valve further comprises a valve opening regulating mechanism which comprises: a valve opening setting shaft a base end of which is in contact with a rear face of the corresponding main or sub piston which face is on the side of the piston toward which the piston is retracted when the corresponding valve element is separated from the corresponding valve seat; and a valve opening setting shaft driving mechanism capable of continuously driving the valve opening setting shaft in an advance or retract direction to a desired axial position, so that a distance of the corresponding main or sub valve element from the corresponding main or sub valve seat, which defines an opening degree of the corresponding main or sub valve, is controllable by controlling an operating position of the corresponding main or sub piston which is determined in accordance with the displacement of the valve opening setting shaft by the valve opening setting shaft driving mechanism. 7. The vacuum regulating valve according to claim 6, wherein the valve opening setting shaft driving mechanism comprises: an electric motor for valve opening control which has an output shaft; and a motion converting mechanism which comprises a rotating screw rod connected to the output shaft of the electric motor for valve opening control, and a internally threaded nut which is mounted on the screw rod such that the internally threaded nut is restrained from turning and capable of moving axially along the screw rod, the motion converting mechanism converting a rotary motion, in the forward and backward directions, of the output shaft of the electric motor for valve opening control into a linear reciprocating motion of the screw rod, and an end of the valve opening setting shaft being joined to the internally threaded nut while the other end of the valve opening setting shaft being a free end which is separably in contact with the corresponding main or sub piston. 8. The vacuum regulating valve according to claim 6, wherein the valve opening regulating mechanism has a sensor for measuring an amount of axial displacement of the valve opening setting shaft, and the valve opening setting shaft driving mechanism operates to control the axial position of the valve opening setting shaft on the basis of an output of the sensor. 9. The vacuum regulating valve according to claim 1, wherein at least one of the main valve element operating unit and the sub valve element operating unit further comprises: an electric motor for valve element operation which has an output shaft; and a motion converting mechanism which comprises a rotating screw rod connected to the output shaft of the electric motor for valve element operation, and a internally threaded nut which is mounted on the screw rod such that the internally threaded nut is restrained from turning and capable of moving axially along the screw rod, the motion converting mechanism converting a rotary motion, in the forward and backward directions, of the output shaft of the electric motor for valve element operation into a linear reciprocating motion of the screw rod, and an end of the corresponding main or sub valve stem being joined to the internally threaded nut. 10. The vacuum regulating valve according to claim 9, wherein each of the main valve element operating unit and the sub valve element operating unit further comprises the electric motor for valve element operation and the motion converting mechanism which converts the rotary motion of the output shaft of the electric motor for valve element operation into the linear reciprocating motion of the screw rod, and the sub valve element operating unit is constructed such that the sub valve stem and the internally threaded nut are joined via a disc-shaped intermediate member which is guided by a plurality of guide pins. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum regulating valve for regulating the pressure in an evacuated vacuum vessel for chemical reaction included in a physical or chemical machine or the like. 2. Description of Related Art A chemical process, such as an etching process, is carried out in a vacuum vessel included in a semiconductor device fabricating system. The vacuum vessel is evacuated at a negative pressure by a vacuum pump. Such a pressure regulating valve is placed in an external line connecting the vacuum vessel to the vacuum pump and has two ports connected, respectively, to a vacuum vessel and a vacuum pump, internal passage connecting the two ports, a valve seat formed in the internal passage, a valve element to be seated on the valve seat to close the pressure regulating valve, and a valve element operating unit, such as one comprising a cylinder actuator, for moving the valve element onto and away from the valve seat to close and open the pressure regulating valve. The vacuum in the vacuum vessel is regulated by opening/closing the valve through the operation of the valve element operating unit. For instance, in reducing the pressure in the vacuum vessel, for instance, fully opening the vacuum regulating valve to rapidly evacuate the vacuum vessel is likely to cause a large volume of the gas in the vessel to flow all at once which leads to an undesirable turbulence in the vacuum vessel and the external and internal passages, with stirring up particles in the vessel and passages. Therefore, there has been proposed an arrangement for improving the gas flow characteristics, as disclosed in JP-A-2001-263532 for instance, where a main fluid passage having a relatively large section area and a sub fluid passage having a relatively small section area are disposed in parallel in a vacuum regulating valve. In operation, the sub fluid passage is first opened to perform in an initial period of a vacuuming operation, and the main fluid passage is subsequently opened to perform the vacuuming operation in full. However, the above conventional valve is somewhat complex in structure, since a sub valve mechanism for opening/closing the sub fluid passage having the relatively small cross section is dually disposed inside a valve element, a valve stem, a piston, etc. of a main valve mechanism for opening/closing the main fluid passage. Thus, there has been a request for a vacuum regulating valve which is simplified in structure. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vacuum regulating valve, which is simple in structure and exhibits improved air flow characteristics in reducing the pressure in a vacuum vessel. To attain the above object, the invention provides a vacuum regulating valve comprising: a main valve which has a relatively large size and comprises: a casing which defines therein a valve chamber extending along an axis of the main valve, and which has: a first main port which is capable of communicating with the valve chamber through a communication opening and is connected to a vacuum vessel; and a second main port connected to a vacuum pump; a main valve seat formed at an outer periphery of the communication opening; a main valve element which is disposed in the valve chamber and seated on and separated from the main valve element; a main valve stem extending in the valve chamber from the main valve element; and a main valve element operating unit which drives the main valve stem to move the main valve element onto and away from the main valve seat; and a sub valve which has a relatively small size, is attached to an external side surface of the casing of the main valve, and comprises: a bypass passage which extends from and outside the casing to bypass the main valve seat; a sub valve seat which is disposed in the bypass passage and has an opening area which is smaller than an opening area of the main valve seat; a sub valve element which is seated on and separated from the sub valve element; a sub valve stem extending from the sub valve element; and a sub valve element operating unit which drives the sub valve stem to move the sub valve element onto and away from the sub valve seat. The vacuum regulating valve is constructed such that the casing has a first connecting hole and a second connecting hole which are formed through the thickness of the casing, and the bypass passage has two opposite ends, one of which serves as a first bypass port connected to the first main port through the first connecting hole, while the other of which serves as a second bypass port connected to the second main port through the second connecting hole. In the vacuum regulating valve, the main valve element operating unit and the sub valve element operating unit may be substantially identically constructed. According to a mode of this invention, the main valve element operating unit comprises: a main piston attached to an end of the main valve stem; a main pressure chamber accommodating a fluid whose pressure acts on the main piston and is controlled to move the main valve element in a direction away from the main valve seat; and a main pilot port for therethrough supplying the main pressure chamber with a pilot fluid, while the sub valve element operating unit comprises: a sub piston attached to an end of the sub valve stem; a sub pressure chamber accommodating a fluid, whose pressure acts on the sub piston and is controlled to move the sub valve element in a direction away from the sub valve seat; and a sub pilot port for therethrough supplying the sub pressure chamber with a pilot fluid, and wherein the main valve further comprises a return spring which biases the main valve element toward the main valve seat, while the sub valve further comprises a return spring which biases the sub valve element toward the sub valve seat. In the vacuum regulating valve of the above mode, the main valve comprises a partition wall whose opposite sides respectively partially defines the valve chamber and the main pressure chamber and the return spring of the main valve is disposed between the partition wall and the main valve element, while the sub valve comprises a cylinder cover which covers a rear side of the sub piston toward which the sub piston is retracted when the sub valve element is separated from the sub valve seat and the return spring of the sub valve is disposed between the sub piston and the cylinder cover. According to a specific mode of the invention, at least one of the main valve operating unit and the sub valve operating unit of the vacuum regulating valve further comprises a valve opening regulating mechanism which comprises: a valve opening setting shaft a base end of which is in contact with a rear face of the corresponding main or sub piston which face is on the side of the piston toward which the piston is retracted when the corresponding valve element is separated from the corresponding valve seat; and a valve opening setting shaft driving mechanism capable of continuously driving the valve opening setting shaft in an advance or retract direction to a desired axial position, so that a distance of the corresponding main or sub valve element from the corresponding main or sub valve seat, which defines an opening degree of the corresponding main or sub valve, is controllable by controlling an operating position of the corresponding main or sub piston which is determined in accordance with the displacement of the valve opening setting shaft by the valve opening setting shaft driving mechanism. In the vacuum regulating valve according to the above specific mode, the valve opening setting shaft driving mechanism comprises: an electric motor for valve opening control which has an output shaft; and a motion converting mechanism which comprises a rotating screw rod connected to the output shaft of the electric motor for valve opening control, and a internally threaded nut which is mounted on the screw rod such that the nut is restrained from turning and capable of moving axially along the screw rod, the motion converting mechanism converting a rotary motion, in the forward and backward directions, of the output shaft of the electric motor for valve opening control into a linear reciprocating motion of the screw rod, and a base end of the valve opening setting shaft being joined to the nut while the other end of the valve opening setting shaft being a free end which is separably in contact with the corresponding main or sub piston. The valve opening regulating mechanism has a sensor for measuring an amount of axial displacement of the valve opening setting shaft, and the valve opening setting shaft driving mechanism operates to control the axial position of the valve opening setting shaft on the basis of an output of the sensor. According to another specific mode of the invention, at least one of the main valve element operating unit and the sub valve element operating unit further comprises: an electric motor for valve element operation which has an output shaft; and a motion converting mechanism which comprises a rotating screw rod connected to the output shaft of the electric motor for valve element operation, and a internally threaded nut which is mounted on the screw rod such that the nut is restrained from turning and capable of moving axially along the screw rod, the motion converting mechanism converting a rotary motion, in the forward and backward directions, of the output shaft of the electric motor for valve element operation into a linear reciprocating motion of the screw rod, and an end of the corresponding main or sub valve stem being joined to the nut. According to a further specific mode of the invention, each of the main valve element operating unit and the sub valve element operating unit further comprises the electric motor for valve element operation and the motion converting mechanism which converts the rotary motion of the output shaft of the electric motor for valve element operation into the linear reciprocating motion of the screw rod, and the sub valve element operating unit is constructed such that the sub valve stem and the nut are joined via a disc-shaped intermediate member which is guided by a plurality of guide pins. The vacuum regulating valve constructed according to the invention is capable of finely and accurately regulating the vacuum in the vacuum vessel, by controlling the opening and closing of the main valve and the sub valve in a coordinated manner or independently. Further, the vacuum regulating valve of this invention, where the sub valve of a relatively small size as prepared separately from the main valve is directly attached to the external side surface of the casing of the main valve, is significantly simplified in structure in comparison with the conventional valve where the structure having the same function as the sub valve of this invention is incorporated in the valve element, shaft and piston of the main valve. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross sectional view showing a vacuum regulating valve according to a first embodiment of the invention in its closed state. FIG. 2 is a cross sectional view of the vacuum regulating valve of FIG. 1 in its open state. FIG. 3 is a graph indicating a flow rate characteristic of the vacuum regulating valve. FIG. 4 is a cross sectional view showing a vacuum regulating valve according to a second embodiment of the invention in its closed state. FIG. 5 is a cross sectional view of the vacuum regulating valve of FIG. 4 in its open state. FIG. 6 is a cross sectional view showing a vacuum regulating valve according to a third embodiment of the invention in its closed state. FIG. 7 is a cross sectional view of the vacuum regulating valve of FIG. 6 in its open state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 shows a vacuum regulating valve V1 according to a first embodiment of the invention. The vacuum regulating valve V1 comprises a main valve 1A of a relatively large size for controlling evacuation in a high flow phase in an evacuation operation, and a sub valve 2A of a relatively small size for controlling evacuation in a low flow phase of the evacuation operation, which serves as a “bypass” valve, as will be described later. The main valve 1A has a main valve principal body 4 having a main valve element 15 for opening and closing a main fluid passage 13, and a main valve element operating unit 5 for bringing the main valve element 15 into its open and closed state. The principal body 4 and the main valve element operating unit 5 are joined in series along an axis L of the main valve 1A of the vacuum regulating valve V1. The principal body 4 has a main valve casing 10 which is a substantially cylindrical hollow column in shape and defines therein a main valve chamber 16 extending along the axis L. However, the shape of the main valve casing 10 may be a substantially square or rectangular column. The main valve casing 10 has a first main port 11 connected to a vacuum vessel 7 and a second main port 12 connected to a vacuum pump 8. The first main port 11 is open at a first end 10a of the main valve casing 10 in the direction of the axis L, while the second main port 12 is open in a side surface of the main valve casing 10 in the direction perpendicular to the direction of the axis L. In the main valve chamber 16, there is defined the main fluid passage 13 connecting the first and second main ports 11, 12, and a main valve seat 14 encircling the first main port 11. More specifically, the main valve seat 14 is formed at the outer periphery of a communication opening 11a of the first main port 11 where the first main port 11 communicates with the main valve chamber 16. The main valve 1A is a poppet valve where the valve element 15 is seated on and separated from the main valve seat 14 to bring the main valve 1A into its closed and open state, and is disposed coaxially with the main valve seat 14, inside the main valve casing 10. The main valve element 15 is a disc-shaped member, and an annular valve seal 17 of a rubber is attached to a peripheral portion on of one of opposite faces of the main valve element 15 which is on the advancing side (the lower side as seen in FIG. 1) and is brought into contact with and away from the main valve seat 14. Further, a generally disc-shaped nose 18 for flow rate control is disposed on the inner side of the valve seal 17 on the face of the main valve element 15 on the advancing side. More specifically, the nose 18 has a tapered shape whose diameter decreases toward the advancing side, and functions to control or restrict a gas flow rate in an initial period (corresponding to the low flow phase) of an evacuation operation by being gradually displaced in the retracting direction so as to progressively increase the degree of valve opening of the main valve 1A. However, providing the nose 18 is not essential. A main valve stem 20 extends inside the main valve casing 10 along the axis L from the central port portion of the face of the main valve element 15 on the retracting side (the upper side as seen in FIG. 1), through a partition wall 31 (on opposite sides of which are disposed the principal body 4 and the main valve element operating unit 5) into the main valve element operating unit 5, so that the other end of the main valve stem 20 (opposite to the end fixed to the main valve element 15) is joined to a main piston 32. Around an axial port portion of the main valve stem 20 on the side of the main valve element 15, there is attached a cylindrical sleeve 21 for defining the open or retracted position of the main valve element 15. The sleeve 21 extends in a length along the main valve stem 20 from the surface of the main valve element 15 on the retracting side, and an end of the sleeve 21 on the retracting side is brought into contact with a contact port portion of the partition wall 31 when the main valve element 15 is retracted to the maximum. On the face of the main valve element 15 on the retracting side (which face will be referred to as “retracting-side face”), there is also disposed a spring seat 22, between which and the partition wall 31 is disposed a return spring 23 in the form of a coiled spring which holds the main valve element 15 against the main valve seat 14. The return spring 23 comprises a first spring 23a of a relatively large diameter and a second spring 23b of a relatively small diameter, which are coaxially disposed. Further, a bellows 24 that is expansible and contractible is disposed such that the bellows 24 encloses the main valve stem 20, sleeve 21 and the return spring 23. The bellows 24 is made of an airtight material such as a metal, and an end of the bellows 24 is attached to the retracting-side face of the main valve element 15, while the opposite end of the bellows 24 is attached to a support plate 25 disposed between an end portion (on the retracting side) of the main valve casing 10 and the partition wall 31. The bellows 24 expands and contracts in accordance with the advancing and retracting movement of the main valve element 15 toward and away from the main valve seat 14. The interior space enclosed by the bellows 24 is open to the exterior space through an aperture not shown. The main valve element operating unit 5 takes the form of a fluid pressure cylinder having a main cylinder casing 30 coaxially joined to a second end 10b of the main valve casing 10. The main cylinder casing 30 has a cylindrical (or square or rectangular columnar) shape similar to that of the main valve casing 10, and one end of the main cylinder casing 30 in the direction of the axis L is closed by the partition wall 31 which separates the main valve casing 10 from the main cylinder casing 30. The main cylinder casing 30 defines therein a main cylinder chamber 33 and slidably receives the main piston 32 via a sealing member 34 and a wear ring 35. As described above, the main valve stem 20 extends through the partition wall 31 into the main cylinder chamber 33, such that the main valve stem 20 is movable in sliding contact with a relevant bore formed through the partition wall 31, so that the end (on the retracting side) of the main valve stem 20 is joined to the main piston 32. Between the partition wall 31 and one of opposite faces of the main piston 32 on the side of the partition wall 32 is formed a main pressure chamber 37, which is connected to a main pilot port 38 open in a side surface of the main cylinder casing 30. A chamber defined between the other of the opposite faces of the main piston 32 and a cylinder cover 40 serves as a breath chamber 39 in communication with the atmosphere. While the main valve 1A is in its closed state as shown in FIG. 1, when the main pressure chamber 37 is provided with a pilot fluid (e.g. a compressed gas) of a pressure as suitably adjusted through the main pilot port 38, the main piston 32 is displaced in the retracting direction or upward when seen in FIG. 1 with the main valve stem 20 also being retracted, compressing the return spring 23, and the main valve element 15 is thereby separated from the main valve seat 14, that is, the main valve 1A is opened, as shown in FIG. 2. On the other hand, when the pilot fluid in the main pressure chamber 37 is released while the main valve 1A is in its open state as shown in FIG. 2, the resilience of the return spring 23 advances the main piston 32 and main valve stem 20 to drive the main valve element 15 onto the main valve seat 14, that is, the main valve 1A is closed. There will now be described the sub valve 2A. The sub valve 2A is attached to the outer side surface of the main valve casing 10 of the main valve 1A at a position near the first main port 11 to be adjacent to the main valve seat 14. The sub valve 2A has a sub valve principal body 41 and a sub valve element operating unit 42, which are joined in the axial direction thereof and constructed substantially identically with the main valve principal body 4 and the main valve element operating unit 5, respectively. In the description below, the elements similar to the corresponding elements of the main valve A1 are only briefly described for avoiding redundancy. It is noted, however, that the axial length of the sub valve 2A is about one third of that of the main valve 1A with each element of the sub valve 2A accordingly scaled down, making the form of some elements of the sub valve 2A slightly different from that of the corresponding elements of the main valve 1A, due to the limit on the dimensions of the elements. Thus, the functional aspect of the sub valve 2A including the fundamental structure and the principle of operation is substantially identical with that of the main valve 1A. As shown in FIG. 1, the principal body 41 of the sub valve 2A has a sub valve casing 45 in which is defined a sub valve chamber 46. The sub valve casing 45 has: a first bypass port 47 and a second bypass port 48 that are formed through a side surface of the sub valve casing 45; a bypass passage 49 having a relatively small cross section and extending through the sub valve chamber 46 to connect the first and second bypass ports 47, 48; a sub valve seat 50 disposed in the bypass passage 49 and having an opening area smaller than that of the main valve seat 14; a sub valve element 51 to be seated on and separated from the sub valve seat 50 so as to bring the sub valve 2A into its closed and open state; a sub valve stem 52 extending from the sub valve element 51 toward the sub valve element operating unit 42; and a bellows 53 which is expansible and contractible and disposed in the sub valve chamber 46 such that the bellows encloses the sub valve stem 52. Similarly to the valve element 15 of the main valve 1A, a nose may be provided to the sub valve element 51. The first bypass port 47 communicates with the first main port 11 through a first connecting hole 56 formed through the casing 10 of the main valve 1A, while the second bypass port 48 communicates, through a second connecting hole 57, with the main valve chamber 16 which is in communication with the second main port 12. Thus, the second bypass port 48 is in communication with the main port 12. By this arrangement, the bypass passage 49 extends outside the main valve casing 10 and bypasses the main valve seat 14. As shown in FIGS. 1 and 2, the sub valve element operating unit 42 has a sub cylinder casing 60 defining therein a sub cylinder chamber 63. An end of the sub cylinder chamber 63 is closed by a partition wall 61 integral with a sub cylinder casing 60, and the other end of the sub cylinder chamber 63 is closed by a cylinder cover 70. In the sub cylinder chamber 63 is slidably accommodated a sub piston 62 via a sealing member 64. The sub piston 62 is joined to an end (on the retracting side) of the sub valve stem 52, which extends through the partition wall 61 into the sub cylinder chamber 63 such that the sub valve stem 52 is axially movable in sliding contact with a relevant bore formed through the partition wall 61. Between the sub piston 62 and the partition wall 61 is defined a sub pressure chamber 67 connected to a sub pilot port 68 open in a side surface of the sub cylinder casing 60. There is formed a chamber on the retracting side of the sub piston 62, to serve as a breath chamber 69 in communication with the atmosphere. In the breath chamber 69, a return spring 71 is disposed between the sub piston 62 and the cylinder cover 70. The return spring 71 of the sub valve 2A and the return spring 23 of the main valve 1A are different from each other with respect to their positions in the respective valves, but have an identical function, that is, the return spring 71 holds the sub valve element 51 against the valve seat 50. The operation of the sub valve 2A is substantially identical with that of the main valve 1A and is not described for avoiding redundancy. FIG. 3 shows a graph indicating the flow rate characteristic of each of the main and sub valves 1A, 2A; namely, reference sign M denotes the flow rate characteristic of the main valve 1A, while reference sign S denotes the flow rate characteristic of the sub valve 2A. The vacuum regulating valve V1 constructed as described above regulates the vacuum in the vacuum vessel 7, by supplying the pilot fluids to the main and sub pressure chambers 37, 67 through the pilot ports 38, 68 of the main and sub valves 1A, 2A, respectively, from a controller (not shown), based on the output of a pressure sensor provided to the vacuum vessel 7, to thereby drive the main and sub pistons 32, 62 to advance and retract the main and sub valve elements 15, 51 to move the valve elements 15, 51 onto and away from the main and sub valve seats 14, 50, respectively. In this regard, the sub valve 2A of the relatively small size is selectively operated in the low flow phase of a flow rate control operation, such as the initial period of a valve opening operation for opening the vacuum regulating valve V1 and the terminal period of a valve closing operation for closing the valve V1, while the main valve 1A of the relatively large size is operated in the other phase, i.e., high flow phase, of the flow rate control operation, or when a rapid evacuation is performed. For instance, when the pressure in the vacuum vessel 7 is decreased, the sub piston 62 is initially driven to separate the sub valve element 51 from the sub valve seat 50 so that a small volume of gas is discharged through the bypass passage 49, and then, with a slight time lag, the main piston 32 is driven to allow the main valve 1A to be opened so as to perform the rest of the evacuation or discharge. In the above arrangement, the pilot fluids supplied through the main and sub pilot ports 38, 68 may or may not be of the same pressure. In the case where the pilot fluids are of the same pressure, it may be arranged such that the pilot port 68 of the sub valve 2A is omitted and the pressure chamber 37 of the main valve 1A and the pressure chamber 67 of the sub valve 2A are directly connected to each other so as to supply both pressure chambers 37, 67 with a common pilot fluid. For instance, it may be arranged such that a communication hole for communication with the main pressure chamber 37 is formed through a side surface of the main cylinder casing 30 while another communication hole for communication with the sub pressure chamber 67 is formed through a side surface of the sub cylinder casing 60, and these communication holes are connected to each other by some means. In either case, i.e., whether the pilot fluids supplied to the main and sub pressure chambers are the same or not the same, the pressure receiving areas of the main and sub valve elements 15, 51, the spring forces of the return springs 23, 71, and the pressures of the pilot fluids supplied to the pressure chambers 37, 67 need be determined in relationship with one another, so that the sub valve 2A is opened slightly prior to an opening of the main valve 1A. The way of operation of the vacuum regulating valve V1 is not limited to the one described above, but may be various; the valve V1 can be used in various ways by opening and closing the main and sub valves 1A, 2A in a coordinated manner or independently of each other, as needed. For instance, once the pressure in the vacuum vessel 7 has been reduced to a level, the main valve 1A is closed; when the vacuum in the vacuum vessel 7 is changed due to a reactant gas or others supplied thereto, an evacuation operation is performed by opening and closing the sub valve 2A so as to hold the vacuum level constant. The present vacuum regulating valve where the sub valve 2A of a relatively small size which is separately prepared from the main valve 1A is directly attached to the outer side surface of the main valve casing 10, is significantly simplified in structure, compared to the conventional valve where a closing/opening mechanism having the same function as the sub valve 2A is dually incorporated in the inside of the valve element 15, shaft 20 and piston 32 of the main valve 1A. FIGS. 4 and 5 shows a vacuum regulating valve V2 according to a second embodiment of the invention, which is different from the vacuum regulating valve V1 according to the first embodiment in that the main valve element operating unit 5 of a main valve 1B and the sub valve element operating unit 42 of a sub valve 2B respectively further comprises a main valve opening regulating mechanism 80 and a sub valve opening regulating mechanism 90, which operate to set or adjust the opening of the main and sub valve elements 15, 51, respectively. The fundamental structure and operation of the main and sub valves 1B, 2B are substantially identical with those of the main and sub valves 1A, 2A of the vacuum regulating valve V1 according to the first embodiment. Therefore, the following description of the second embodiment focuses on the main and sub valve opening regulating mechanisms 80, 90; as to the rest, other major elements are denoted by the same reference numerals used in the first embodiment and not illustrated here. The main valve opening regulating mechanism 80 provided to the main valve 1B is incorporated in an end block 81 which is coaxially joined to an end (on the retracting side) of the main cylinder casing 30 and serves as a cylinder cover as well. The end block 81 is a cylindrical (or square or rectangular columnar) member having a shape similar to that of the main cylinder casing 30, and incorporates a valve opening setting shaft 82 an end of which on the advancing side is in contact with a face of a main piston 32 on the retracting side, and a valve opening setting shaft driving mechanism 83 which is capable of continuously advancing and retracting the valve opening setting shaft 82 to a desired axial position. The main valve opening regulating mechanism 80 is constituted by the valve opening setting shaft 82 and the valve opening setting shaft driving mechanism 83. In operation, the valve opening setting shaft driving mechanism 83 operates to displace the valve opening setting shaft 82 to a desired axial position to control the operating position of the main piston 32, so as to set the distance of the main valve element 15 from the main valve seat 14, i.e., the degree of valve opening of the main valve 1B. The valve opening setting shaft driving mechanism 83 comprises an electric motor 84 for valve opening control which is rotatable in the forward and backward directions and has an output shaft, and a motion converting mechanism 85 which converts the rotary motion of the output shaft of the motor 84 in the forward and backward directions into a linear reciprocating motion. The motor 84 is disposed inside a motor chamber 81a formed in an axial end portion of the end block 81, while the motion converting mechanism 85 is accommodated in a cavity 81b connecting the motor chamber 81a and a breath chamber 39. In FIG. 4, reference numeral 86 denotes an end cover which closes an end of the end block 81. The motion converting mechanism 85 comprises a rotating screw rod 85a and a internally threaded nut 85b. The screw rod 85a is connected to the output shaft 84a of the motor 84 to be driven by the motor 84. The internally threaded nut 85b is mounted on the screw rod 85a such that the nut 85b is restrained from turning and capable of moving along the screw rod 85a. The base end of the valve opening setting shaft 82 (which has a cylindrical shape) is fastened to the nut 85b with a screw 87. The other end 82a of the valve opening setting shaft 82 is a free end extending out of the cavity 81b and is separably in contact with the central port portion of the face of the main piston 32 on the retracting side. Accordingly, the screw rod 85a and nut 85b that together constitute the motion converting mechanism 85, the valve opening setting shaft 82, main piston 32, main valve stem 20, main valve element 15 and main valve seat 14 are all disposed on the axis L. Although the first main port 11 is also disposed on the axis L in this specific case, it is not essential to dispose the first main port 11 on the axis L. In the main valve opening regulating mechanism 80, when the electric motor 84 for valve opening control is rotated in the forward and backward directions, the rotary motion is converted by the motion converting mechanism 85 into the linear reciprocating motion which is transmitted to the valve opening setting shaft 82. Thus, the valve opening setting shaft 82 reciprocates a distance corresponding to the amount of rotation of the motor 84. Accordingly, when the main piston 32 is operated to separate the valve element 15 from the valve seat 14 while the main valve 1B is in the closed state as shown in FIG. 4, the motor 84 is rotated in a required amount to retract the valve opening setting shaft 82 to a position as set, so that the main piston 32 in contact with the valve opening setting shaft 82 also retracts to the corresponding operating position and stops there, as shown in FIG. 5. The valve opening is thus set, namely, the valve opening is continuously controllable to a desired degree, by controlling the position of the valve opening setting shaft 82 by the motor 84. On the other hand, when the valve opening is changed while the main valve 1B is in the open state as shown in FIG. 5, the valve opening setting shaft 82 is displaced by the driving mechanism 83 to change the operating position of the main piston 32. More specifically, when the valve opening degree of the main valve 1B is to be increased from an intermediate opening degree (corresponding to a state of the main valve 1B between the fully open state and the closed state), the valve opening setting shaft 82 is retracted to move the main piston 32 in the direction to further open the main valve 1B by the pilot fluid introduced into the main pressure chamber 37. When the valve opening degree of the main valve 1B is to be decreased from an intermediate opening degree, on the other hand, the valve opening setting shaft 82 is advanced to push and advance the main piston 32 in the direction to close the main valve 1B to a certain extent. In this regard, the pressure of the pilot fluid in the main pressure chamber 37 is adjusted so as to reduce the necessary force to push the piston 32 as required of the valve opening setting shaft 82. Where the vacuum vessel 7 is to be hermetically closed while the vacuum therein being held at a constant value, or where the main valve 1B is to be closed, for instance in an emergency, the pilot fluid in the main pressure chamber 37 is discharged so that the main valve element 15 is advanced together with the main piston 32 and the main valve stem 20 by the resilience of the return spring 23 to eventually bring the valve element 15 into contact with the valve seat 14. In this regard, to enable the valve opening setting shaft 82 to reciprocate only a required distance, the main valve opening regulating mechanism 80 has a sensor 88 capable of detecting an amount of displacement of the valve opening setting shaft 82. The sensor 88 consists of a rotary encoder attached to the motor 84, detects the amount of rotation of the motor 84 so as to indirectly detect the amount of displacement of the valve opening setting shaft 82, and outputs a detection signal based on which a controller (not shown) controls the motor 84 to continuously displace the valve opening setting shaft 82 to a desired axial position. However, the sensor 88 may be of a type capable of directly detecting the position of the valve opening setting shaft 82; for instance, where magnetic or optical calibrations are provided on the valve opening setting shaft 82, a magnetic sensor or an optical sensor which reads the calibrations is employed. The sub valve opening regulating mechanism 90 will be described. The sub valve opening regulating mechanism 90 provided to the sub valve 2B is substantially identical with the valve opening regulating mechanism 80 for the main valve 1B in structure and operation, except that the sub valve opening regulating mechanism 90 is scaled down with respect to the valve opening regulating mechanism 80 for the main valve 1B, with some elements (e.g., end block 91 and valve opening setting shaft 92) of the sub valve 2B accordingly slightly modified in form from the corresponding elements of the main valve 1B. Hence, major elements similar to the corresponding elements of the main valve opening regulating mechanism 80 are denoted by respective reference numerals each being a sum of ten and the number of the corresponding reference numeral in the mechanism 80, and not described here. The vacuum regulating valve V2 according to the second embodiment regulates the vacuum in the vacuum vessel 7 by operating the main and sub valves 1B, 2B in a coordinated manner or independently of each other, just like the vacuum regulating valve V1 according to the first embodiment. However, since the valve V2 of the second embodiment is capable of continuously setting or adjusting the valve openings of the main and sub valves 1B, 2B by the main and sub valve opening regulating mechanisms 80, 90, respectively, it is enabled to further finely and accurately control the flow rate in comparison to the valve V1 of the first embodiment. FIGS. 6 and 7 shows a vacuum regulating valve V3 according to a third embodiment, where a main valve element operating unit 5 of a main valve 1C and a sub valve element operating unit 42 of a sub valve 2C are constructed such that electric motors 100, 110 are employed for operating or driving a main valve element 15 and a sub valve element 51, respectively. This differentiate the valve V3 from the valves V1, V2 of the first and second embodiments where the fluid pressure cylinder is employed as the driving source of the main and sub valve element operating units 5, 42. More specifically described, the main valve 1C of the vacuum regulating valve V3 of the third embodiment has a main valve principal body 4 having a main valve element 15 for opening and closing a main fluid passage 13, and a main valve element operating unit 5 for operating the main valve element 15. The main valve principal body 4 and main valve element operating unit 5 are joined in series along an axis L of the main valve 1C. The main valve principal body 4 has a main valve casing 10 in which is defined a main valve chamber 16, a first main port 11 and a second main port 12, a main fluid passage 13, a main valve seat 14 formed in the main fluid passage 13, a main valve element 15 to be seated and separated from the main valve seat 14, a main valve stem 20 extending from the main valve element 15, and a bellows 24. An end portion 20a of the shaft 20 has a cylindrical shape and is joined to a internally threaded nut 101b of a motion converting mechanism 101. The thus constructed main valve principal body 4 of the third embodiment is substantially identical with the principal body 4 of the first and second embodiments in structure, except that the main valve stem 20 is slightly differently formed and the return spring is omitted. Therefore, the major, identical elements are referred to by the same reference numerals as used in the first and second embodiments, and further illustration thereof is dispensed with. The main valve element operating unit 5 has an end block 103 attached to an end of the main valve casing 10. The end block 103 has a cylindrical or square (or rectangular) columnar shape the same as that of the main valve casing 10, and has a partition wall 31 closing an end of the main valve chamber 16, a cylindrical port portion 31a extending from the partition wall 31 along the axis L of the main valve 1C into the main valve chamber 16, a motor chamber 104 formed in an end portion of the end block, a cavity 105 formed through the partition wall 31 and the cylindrical port portion 31a so as to connect the motor chamber 104 and the main valve chamber 16. The motor 100 for operating a main valve element 15 is disposed in the motor chamber 104, while the motion converting mechanism 101 is disposed in the cavity 105. In FIG. 6, reference numeral 106 denotes an end cover covering an end of the motor chamber 104. The motion converting mechanism 101 comprises a rotating screw rod 101a connected to and rotated by an output shaft 101a of the motor 100, and the internally threaded nut 101b which is mounted on the screw rod 101a such that the internally threaded nut 101b is not rotatable about the screw rod 101a but axially displaceable relatively to the screw rod 101a. An end of the main valve stem 20 is fastened to the internally threaded nut 101b with a screw 107. Thus, the screw rod 101a, internally threaded nut 101b, main valve stem 20, main valve element 15 and the main valve seat 14 are disposed on the same axis L. Although the first main port 11 is also disposed on the axis L in this specific case, it is not essential to dispose the first main port 11 on the axis L. In the main valve 1C as shown in FIG. 6, when the motor 100 is rotated in the forward direction while the main valve element 15 is seated on the main valve seat 14, the rotary motion is converted by the motion converting mechanism 101 into a linear motion and the internally threaded nut 101b is retracted along the screw rod 101a with the main valve stem 20 also retracting, separating the main valve element 15 from the main valve seat 14 and thus opening the valve 1C, as shown in FIG. 7. On the other hand, when the motor 100 is rotated in the backward direction while the main valve element 15 is separated from the main valve seat 14, as shown in FIG. 7, the internally threaded nut 101b is advanced together with the main valve stem 20 and main valve element 15, to have the main valve element 15 seated on the main valve seat 14, as shown FIG. 6. The main valve element 15 can be stopped at a desired position, so that the distance of the main valve element 15 from the main valve seat 14, that is, the degree of opening of the main valve 1C, is continuously settable or adjustable. To this end, the main valve element operating unit 5 has a sensor 108 capable of detecting the amount of displacement of the main valve stem 20 or the internally threaded nut 101b. The sensor 108 consists of a rotary encoder attached to the motor 100 for operating the main valve element 15, which detects the amount of rotation of the motor 100 to indirectly detect the amount of displacement of the main valve stem 20 or the internally threaded nut 101b, and outputs a detection signal based on which a controller (not shown) controls the rotation of the motor 100, thereby continuously operating or driving the main valve element 15 to a proper position. However, the sensor may be of a type directly detecting the main valve stem 20 or internally threaded nut 101b; for instance, where magnetic or optical calibrations are provided on the main valve stem 20 or internally threaded nut 101b, a magnetic sensor or an optical sensor which reads the calibrations is employed. The sub valve 2C has a sub valve principal body 41 and a sub valve element operating unit 42, that are substantially identical with the main valve principal body 4 and main valve element operating unit 5 of the main valve 1C, respectively, in structure and operation. The sub valve principal body 41 has, as shown in FIG. 6: the sub valve casing 45 in which is defined a sub valve chamber 46; a first bypass port 47 and a second bypass port 48; a bypass passage 49; a sub valve seat 50 disposed in the bypass passage 49; a sub valve element 51 to be seated on and separated from the sub valve seat 50 so as to bring the sub valve 2C into its closed and open state; a sub valve stem 52 extending from the sub valve element 51; and a bellows 53 disposed such that the bellows encloses the sub valve stem 52. The details of the structure of these members constituting the sub valve 2C, preferred modifications of the sub valve 2C, etc. are substantially identical with those of the sub valves 2A, 2B of the first and second embodiments. Thus, the major, identical elements of the sub valve 2C are denoted by the same reference numerals as used in the first and second embodiments and further illustration thereof is dispensed with. The sub valve element operating unit 42 is identical with the main valve element operating unit 5 in fundamental structure and operation, but slightly different in details, namely: an end block 113 is sectioned into two parts, i.e., a first block 113a on the side of the sub valve principal body 41 and a second block 113b on the opposite side; a motor 110 is disposed in a motor chamber 114 defined between the second block 113b and an end cover 116; a motion converting mechanism 111 comprising a rotating screw rod 111a and a internally threaded nut 111b is disposed in a cavity 115 defined between the two blocks 113a, 113b; and a disc-shaped intermediate member 119 is disposed to connect the internally threaded nut 111b and the sub valve stem 52. Thus, the intermediate member 119 corresponds to the cylindrical end portion 20a of the main valve stem 20 of the main valve element operating unit 4. The intermediate member 119 is constituted by two members, namely, a first member 119a of a relatively large diameter and a second member 119b of a relatively small diameter. In assembling the sub valve 2C, the first member 119a is first joined to the sub valve stem 52 with a screw 117, and the second member 119b is then integrally joined to the first member 119a such that the second member 119b covers the screw 117. The second member 119b is joined to the internally threaded nut 111b. In the cavity 115 are provided a plurality of guide pins 120 each extending through the first member 119a and between the first and second blocks 113a, 113b. The displacement of the intermediate member 119 is guided by the guide pins 120. In FIG. 7, reference numeral 118 denotes a sensor. The vacuum regulating valve V3 according to the third embodiment regulates the vacuum in the vacuum vessel 7 by controlling the main and sub valves 1C, 2C by a controller (not shown) in a coordinated manner or independently of each other, just like the vacuum regulating valves V1, V2 according to the first and second embodiments; more specifically, the controller determines an amount of a driving current to be supplied to the motors 100, 110 of the main and sub valves 1C, 2C based on an output of a pressure sensor provided to the vacuum vessel 7, and operates the motors 100, 110 with the determined amount of the current, so as to operate the valves 1C, 2C as described above. In this regard, since the main and sub valve element operating units 5, 42 can continuously set or adjust the valve opening of the main and sub valves 1C, 2C, the control of the flow rate can be finely and accurately performed. Although in each of the above embodiments structures of the main and sub valves 1A & 2A; 1B & 2B; 1C & 2C are substantially identical with each other, they may be different. For instance, the sub valve 2B or 2C of the second or third embodiment may be attached to the main valve 1A of the first embodiment; the sub valve 2A or 2C of the first or third embodiment may be attached to the main valve 1B of the second embodiment; or, the sub valve 2A or 2B of the first or second embodiment may be attached to the main valve 1C of the third embodiment. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a vacuum regulating valve for regulating the pressure in an evacuated vacuum vessel for chemical reaction included in a physical or chemical machine or the like. 2. Description of Related Art A chemical process, such as an etching process, is carried out in a vacuum vessel included in a semiconductor device fabricating system. The vacuum vessel is evacuated at a negative pressure by a vacuum pump. Such a pressure regulating valve is placed in an external line connecting the vacuum vessel to the vacuum pump and has two ports connected, respectively, to a vacuum vessel and a vacuum pump, internal passage connecting the two ports, a valve seat formed in the internal passage, a valve element to be seated on the valve seat to close the pressure regulating valve, and a valve element operating unit, such as one comprising a cylinder actuator, for moving the valve element onto and away from the valve seat to close and open the pressure regulating valve. The vacuum in the vacuum vessel is regulated by opening/closing the valve through the operation of the valve element operating unit. For instance, in reducing the pressure in the vacuum vessel, for instance, fully opening the vacuum regulating valve to rapidly evacuate the vacuum vessel is likely to cause a large volume of the gas in the vessel to flow all at once which leads to an undesirable turbulence in the vacuum vessel and the external and internal passages, with stirring up particles in the vessel and passages. Therefore, there has been proposed an arrangement for improving the gas flow characteristics, as disclosed in JP-A-2001-263532 for instance, where a main fluid passage having a relatively large section area and a sub fluid passage having a relatively small section area are disposed in parallel in a vacuum regulating valve. In operation, the sub fluid passage is first opened to perform in an initial period of a vacuuming operation, and the main fluid passage is subsequently opened to perform the vacuuming operation in full. However, the above conventional valve is somewhat complex in structure, since a sub valve mechanism for opening/closing the sub fluid passage having the relatively small cross section is dually disposed inside a valve element, a valve stem, a piston, etc. of a main valve mechanism for opening/closing the main fluid passage. Thus, there has been a request for a vacuum regulating valve which is simplified in structure. | <SOH> SUMMARY OF THE INVENTION <EOH>Therefore, an object of the present invention is to provide a vacuum regulating valve, which is simple in structure and exhibits improved air flow characteristics in reducing the pressure in a vacuum vessel. To attain the above object, the invention provides a vacuum regulating valve comprising: a main valve which has a relatively large size and comprises: a casing which defines therein a valve chamber extending along an axis of the main valve, and which has: a first main port which is capable of communicating with the valve chamber through a communication opening and is connected to a vacuum vessel; and a second main port connected to a vacuum pump; a main valve seat formed at an outer periphery of the communication opening; a main valve element which is disposed in the valve chamber and seated on and separated from the main valve element; a main valve stem extending in the valve chamber from the main valve element; and a main valve element operating unit which drives the main valve stem to move the main valve element onto and away from the main valve seat; and a sub valve which has a relatively small size, is attached to an external side surface of the casing of the main valve, and comprises: a bypass passage which extends from and outside the casing to bypass the main valve seat; a sub valve seat which is disposed in the bypass passage and has an opening area which is smaller than an opening area of the main valve seat; a sub valve element which is seated on and separated from the sub valve element; a sub valve stem extending from the sub valve element; and a sub valve element operating unit which drives the sub valve stem to move the sub valve element onto and away from the sub valve seat. The vacuum regulating valve is constructed such that the casing has a first connecting hole and a second connecting hole which are formed through the thickness of the casing, and the bypass passage has two opposite ends, one of which serves as a first bypass port connected to the first main port through the first connecting hole, while the other of which serves as a second bypass port connected to the second main port through the second connecting hole. In the vacuum regulating valve, the main valve element operating unit and the sub valve element operating unit may be substantially identically constructed. According to a mode of this invention, the main valve element operating unit comprises: a main piston attached to an end of the main valve stem; a main pressure chamber accommodating a fluid whose pressure acts on the main piston and is controlled to move the main valve element in a direction away from the main valve seat; and a main pilot port for therethrough supplying the main pressure chamber with a pilot fluid, while the sub valve element operating unit comprises: a sub piston attached to an end of the sub valve stem; a sub pressure chamber accommodating a fluid, whose pressure acts on the sub piston and is controlled to move the sub valve element in a direction away from the sub valve seat; and a sub pilot port for therethrough supplying the sub pressure chamber with a pilot fluid, and wherein the main valve further comprises a return spring which biases the main valve element toward the main valve seat, while the sub valve further comprises a return spring which biases the sub valve element toward the sub valve seat. In the vacuum regulating valve of the above mode, the main valve comprises a partition wall whose opposite sides respectively partially defines the valve chamber and the main pressure chamber and the return spring of the main valve is disposed between the partition wall and the main valve element, while the sub valve comprises a cylinder cover which covers a rear side of the sub piston toward which the sub piston is retracted when the sub valve element is separated from the sub valve seat and the return spring of the sub valve is disposed between the sub piston and the cylinder cover. According to a specific mode of the invention, at least one of the main valve operating unit and the sub valve operating unit of the vacuum regulating valve further comprises a valve opening regulating mechanism which comprises: a valve opening setting shaft a base end of which is in contact with a rear face of the corresponding main or sub piston which face is on the side of the piston toward which the piston is retracted when the corresponding valve element is separated from the corresponding valve seat; and a valve opening setting shaft driving mechanism capable of continuously driving the valve opening setting shaft in an advance or retract direction to a desired axial position, so that a distance of the corresponding main or sub valve element from the corresponding main or sub valve seat, which defines an opening degree of the corresponding main or sub valve, is controllable by controlling an operating position of the corresponding main or sub piston which is determined in accordance with the displacement of the valve opening setting shaft by the valve opening setting shaft driving mechanism. In the vacuum regulating valve according to the above specific mode, the valve opening setting shaft driving mechanism comprises: an electric motor for valve opening control which has an output shaft; and a motion converting mechanism which comprises a rotating screw rod connected to the output shaft of the electric motor for valve opening control, and a internally threaded nut which is mounted on the screw rod such that the nut is restrained from turning and capable of moving axially along the screw rod, the motion converting mechanism converting a rotary motion, in the forward and backward directions, of the output shaft of the electric motor for valve opening control into a linear reciprocating motion of the screw rod, and a base end of the valve opening setting shaft being joined to the nut while the other end of the valve opening setting shaft being a free end which is separably in contact with the corresponding main or sub piston. The valve opening regulating mechanism has a sensor for measuring an amount of axial displacement of the valve opening setting shaft, and the valve opening setting shaft driving mechanism operates to control the axial position of the valve opening setting shaft on the basis of an output of the sensor. According to another specific mode of the invention, at least one of the main valve element operating unit and the sub valve element operating unit further comprises: an electric motor for valve element operation which has an output shaft; and a motion converting mechanism which comprises a rotating screw rod connected to the output shaft of the electric motor for valve element operation, and a internally threaded nut which is mounted on the screw rod such that the nut is restrained from turning and capable of moving axially along the screw rod, the motion converting mechanism converting a rotary motion, in the forward and backward directions, of the output shaft of the electric motor for valve element operation into a linear reciprocating motion of the screw rod, and an end of the corresponding main or sub valve stem being joined to the nut. According to a further specific mode of the invention, each of the main valve element operating unit and the sub valve element operating unit further comprises the electric motor for valve element operation and the motion converting mechanism which converts the rotary motion of the output shaft of the electric motor for valve element operation into the linear reciprocating motion of the screw rod, and the sub valve element operating unit is constructed such that the sub valve stem and the nut are joined via a disc-shaped intermediate member which is guided by a plurality of guide pins. The vacuum regulating valve constructed according to the invention is capable of finely and accurately regulating the vacuum in the vacuum vessel, by controlling the opening and closing of the main valve and the sub valve in a coordinated manner or independently. Further, the vacuum regulating valve of this invention, where the sub valve of a relatively small size as prepared separately from the main valve is directly attached to the external side surface of the casing of the main valve, is significantly simplified in structure in comparison with the conventional valve where the structure having the same function as the sub valve of this invention is incorporated in the valve element, shaft and piston of the main valve. | 20040712 | 20070116 | 20050303 | 96424.0 | 0 | HEPPERLE, STEPHEN M | VACUUM REGULATING VALVE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,483 | ACCEPTED | Compositions and methods for analysis of nucleic acids | Disclosed are a number of methods that can be used in a variety of embodiments, including, creation of a nucleic acid terminated at one or more selected bases, sequence analysis of nucleic acids, mapping of sequence motifs within a nucleic acid, positional mapping of nucleic acid clones, and analysis of telomeric regions. The methods utilize double-stranded templates, and in most aspects involve a strand replacement reaction initiated at one or more random or specific locations created in a nucleic acid molecule, and in certain aspects utilizing an oligonucleotide primer. | 1-104. (cancelled) 105. A method for preparing a DNA molecule comprising the steps of: a) obtaining a sample of DNA wherein the sample includes DNA molecules that have been fragmented enzymatically and that do not include a 3′ hydroxyl group; and b) conditioning DNA fragments of the sample that lack a 3′ hydroxyl by incorporating a 3′ hydroxyl group thereon. 106. The method of claim 105, wherein the DNA molecules have been fragmented using an endonuclease. 107. The method of claim 106, wherein the DNA molecules have been fragmented through the use of a restriction endonuclease. 108. The method of claim 107, wherein the DNA molecules have been fragmented through the use of a restriction endonuclease having a two base recognition sequence. 109. The method of claim 107, wherein the DNA molecules have been fragmented through the use of a restriction endonuclease having a four base recognition sequence. 110. The method of claim 107, wherein the restriction endonuclease has introduced random double strand breaks into DNA molecules. 111. The method of claim 106, wherein the endonuclease introduced a blunt end. 112. The method of claim 105, wherein DNA fragments that lack a 3′ hydroxyl are conditioned through the use of a 3′ exonuclease. 113. The method of claim 112, wherein the 3′ exonuclease is exonuclease III. 114. The method of claim 105, wherein the DNA fragments that lack a 3′ hydroxyl are conditioned through the use of a DNA polymerase that possesses 3′ to 5′ exonuclease activity. 115. The method of claim 105, further comprising attaching an oligonucleotide adaptor to the conditioned DNA fragments. 116. The method of claim 115, wherein the oligonucleotide adaptor is a double-stranded oligonucleotide adaptor. 117. The method of claim 116, wherein the double-stranded oligonucleotide adaptor is attached to the conditioned DNA by only one of its two strands. 118. The method of claim 117, wherein the double stranded adaptor is attached to the conditioned DNA by means of a 5′ terminus of the adaptor. 119. The method of claim 118, wherein the double-stranded oligonucleotide adaptor is blocked at at least one of its 3′ termini. 120. The method of claim 119, wherein the double-stranded oligonucleotide adaptor is blocked at both of its 3′ termini. 121. The method of claim 105, wherein the conditioned DNA fragments are amplified. 122. The method of claim 121, wherein DNA fragments are amplified through a PCR reaction. 123. The method of claim 122, wherein the DNA fragments are amplified through a PCR reaction through the use of double-stranded adaptors that have been attached to the conditioned DNA fragments. 124. The method of claim 105, further defined as comprising the steps of: a) obtaining a sample of DNA wherein the sample includes DNA fragments that do not include a 3′ hydroxyl group, wherein the sample has been subjected to fragmentation; b) conditioning DNA fragments of the sample that lack a 3′ hydroxyl by incorporating a 3′ hydroxyl group thereon; c) attaching adaptors to DNA fragments of the sample; and d) amplifying DNA fragments of the sample through the use of the adaptors. | BACKGROUND OF THE INVENTION The present application is a continuation-in-part of co-pending U.S. patent application Ser. No. 09/035,677, filed Mar. 5, 1998, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 08/811,804 filed Mar. 5, 1997, the entire texts of which are specifically incorporated herein by reference without disclaimer. The government owns rights in the present invention pursuant to grant number MCB 9514196 from the National Science Foundation. 1. FIELD OF THE INVENTION The present invention relates generally to the field of nucleic acid analysis. More particularly, it concerns the sequencing and mapping of double-stranded nucleic acid templates. 2. DESCRIPTION OF RELATED ART An aggressive research effort to sequence the entire human genome is proceeding in the laboratories of genetic researchers throughout the country. The project is called the Human Genome Project (HGP). It is a daunting task given that it involves the complete characterization of the archetypal human genome sequence which comprises 3×109 DNA nucleotide base pairs. Early estimates for completing the task within fifteen years hinged on the expectation that new technology would be developed in response to the pressing need for faster methods of DNA sequencing and improved DNA mapping techniques. Currently physical mapping is used to identify overlapping clones of DNA so that all of the DNA in a particular region can be sequenced or otherwise studied. There are two basic techniques of physical mapping. First, all candidate overlapping clones can be restricted with a series of restriction enzymes and the restriction fragments separated by gel electrophoresis. Overlapping clones will share some DNA sequences and thus some common restriction fragments. By comparing the restriction fragment lengths from a number of clones, the extent of overlap between any two clones can be determined. This process is very tedious and can only evaluate a limited number of candidate clones. Second, if a large number of sequence tagged sites are known in the region studied, the DNA from those sequence tagged sites can be labeled and hybridized to the candidate clones. Clones that hybridize to the same sequence tagged sites are identified as overlapping. If many sequence tagged sites are shared between two clones, it is assumed that the overlap is extensive. Sequence tagged sites give a lot of information from a limited number of hybridization reaction, however, most regions of most genomes do not have extensive sequence tagged site resources. Both methods suffer from lack of direct correspondence between the sequence and the restriction sites or sequence tagged site locations. Current DNA sequencing approaches generally incorporate the fundamentals of either the Sanger sequencing method or the Maxam and Gilbert sequencing method, two techniques that were first introduced in the 1970's (Sanger et al, 1977; Maxam and Gilbert, 1977). In the Sanger method, a short oligonucleotide or primer is annealed to a single-stranded template containing the DNA to be sequenced. The primer provides a 3′ hydroxyl group which allows the polymerization of a chain of DNA when a polymerase enzyme and dNTPs are provided. The Sanger method is an enzymatic reaction that utilizes chain-terminating dideoxynucleotides (ddNTPs). ddNTPs are chain-terminating because they lack a 3′-hydroxyl residue which prevents formation of a phosphodiester bond with a succeeding deoxyribonucleotide (dNTP). A small amount of one ddNTP is included with the four conventional dNTPs in a polymerization reaction. Polymerization or DNA synthesis is catalyzed by a DNA polymerase. There is competition between extension of the chain by incorporation of the conventional dNTPs and termination of the chain by incorporation of a ddNTP. The original version of the Sanger method utilized the E. coli DNA polymerase I (“pol I”), which has a polymerization activity, a 3′-5′ exonuclease proofreading activity, and a 5′-3′ exonuclease activity. Later, an improvement to the method was made by using Klenow fragment instead of pol I; Klenow lacks the 5′-3′ exonuclease activity that is detrimental to the sequencing reaction because it leads to partial degradation of template and product DNA. The Klenow fragment has several limitations when used for enzymatic sequencing. One limitation is the low processivity of the enzyme, which generates a high background of fragments that terminate by the random dissociation of the enzyme from the template rather than by the desired termination due to incorporation of a ddNTP. The low processivity also means that the enzyme cannot be used to sequence nucleotides that appear more than ˜250 nucleotides from the 5′ end of the primer. A second limitation is that Klenow cannot efficiently utilize templates which have homopolymer tracts or regions of high secondary structure. The problems caused by secondary structure in the template can be reduced by running the polymerization reaction at 55° C. (Gomer and Firtel, 1985). Improvements to the original Sanger method include the use of polymerases other than the Klenow fragment. Reverse transcriptase has been used to sequence templates that have homopolymeric tracts (Karanthanasis, 1982; Graham et al., 1986). Reverse transciptase is somewhat better than the Klenow enzyme at utilizing templates containing homopolymer tracts. The use of a modified T7 DNA polymerase (Sequenase™) was a significant improvement to the Sanger method (Sambrook et al., 1989; Hunkapiller, 1991). T7 DNA polymerase does not have any inherent 5′-3′ exonuclease activity and has a reduced selectivity against incorporation of ddNTP. However, the 3′-5′ exonuclease activity leads to degradation of some of the oligonucleotide primers. Sequenase™ is a chemically-modified T7 DNA polymerase that has reduced 3′ to 5′ exonuclease activity (Tabor et al., 1987). Sequenase™ version 2.0 is a genetically engineered form of the T7 polymerase which completely lacks 3′ to 5′ exonuclease activity. Sequenase has a very high processivity and high rate of polymerization. It can efficiently incorporate nucleotide analogs such as dITP and 7-deaza-dGTP which are used to resolve regions of compression in sequencing gels. In regions of DNA containing a high G+C content, Hoogsteen bond formation can occur which leads to compressions in the DNA. These compressions result in aberrant migration patterns of oligonucleotide strands on sequencing gels. Because these base analogs pair weakly with conventional nucleotides, intrastrand secondary structures during electrophoresis are alleviated. In contrast, Klenow does not incorporate these analogs as efficiently. The use of Taq DNA polymerase and mutants thereof is a more recent addition to the improvements of the Sanger method (U.S. Pat. No. 5,075,216). Taq polymerase is a thermostable enzyme which works efficiently at 70-75° C. The ability to catalyze DNA synthesis at elevated temperature makes Taq polymerase useful for sequencing templates which have extensive secondary structures at 37° C. (the standard temperature used for Klenow and Sequenase™ reactions). Taq polymerase, like Sequenase™, has a high degree of processivity and like Sequenase 2.0, it lacks 3′ to 5′ nuclease activity. The thermal stability of Taq and related enzymes (such as Tth and Thermosequenase™) provides an advantage over T7 polymerase (and all mutants thereof) in that these thermally stable enzymes can be used for cycle sequencing which amplifies the DNA during the sequencing reaction, thus allowing sequencing to be performed on smaller amounts of DNA. Optimization of the use of Taq in the standard Sanger method has focused on modifying Taq to eliminate the intrinsic 5′-3′ exonuclease activity and to increase its ability to incorporate ddNTPs (EP 0 655 506 B1). Both the Sanger and the Maxim-Gilbert methods produce populations of radiolabelled or fluorescently labeled polynucleotides of differing lengths which are separated according to size by polyacrylamide gel electrophoresis (PAGE). The nucleotide sequence is determined by analyzing the pattern of size-separated radiolabelled polynucleotides in the gel. The Maxim-Gilbert method involves degrading DNA at a specific base using chemical reagents. The DNA strands terminating at a particular base are denatured and electrophoresed to determine the positions of the particular base. By combining the information from fragments terminating at different bases or combinations of bases the entire DNA sequence can be reconstructed. However, the Maxim-Gilbert method involves dangerous chemicals, and is time- and labor-intensive. Thus, it is no longer used for most applications. The current limitations to conventional applications of the Sanger method include 1) the limited resolving power of polyacrylamide gel electrophoresis, 2) the formation of intermolecular and intramolecular secondary structure of the denatured template in the reaction mixture, which can cause any of the polymerases to prematurely terminate synthesis at specific sites or misincorporate ddNTPs at inappropriate sites, 3) secondary structure of the DNA on the sequencing gels can give rise to compressions of the electrophoretic ladder at specific locations in the sequence, 4) cleavage of the template, primers and products with the 5′-3′ or 3′-5′ exonuclease activities in the polymerases, and 5) mispriming of synthesis due to hybridization of the oligonucleotide primers to multiple sites on the denatured template DNA. The formation of intermolecular and intramolecular secondary structure produces artificial terminations that are incorrectly “read” as the wrong base, gives rise to bands across four lanes (BAFLs) that produce ambiguities in base reading, and decrease the intensity and thus signal-to-noise ratio of the bands. Secondary structure of the DNA on the gels can largely be solved by incorporation of dITP or 7-deaza-dGTP into the synthesized DNA; DNA containing such modified NTPs is less likely to form urea-resistant secondary structure during electrophoresis. Cleavage of the template, primers or products leads to reduction in intensity of bands terminating at the correct positions and increase the background. Mispriming gives rise to background in the gel lanes. The net result is that, although the inherent resolution of polyacrylamide gel electrophoresis alone is as much as 1000 nucleotides, it is common to only be able to correctly read 400-600 nucleotides of a sequence (and sometimes much less) using the conventional Sanger Method, even when using optimized polymerase design and reaction conditions. Some sequences such as repetitive DNA, strings of identical bases (especially guanines, GC-rich sequences and many unique sequences) cannot be sequenced without a high degree of error or uncertainty. In the absence of any methods to consistently sequence DNA longer than about 1000 bases, investigators must subclone the DNA into small fragments and sequence these small fragments. The procedures for doing this in a logical way are very labor intensive, cannot be automated, and are therefore impractical. The most popular technique for large-scale sequencing, the “shotgun” method, involves cloning and sequencing of hundreds or thousands of overlapping DNA fragments. Many of these methods are automated, but require sequencing 5-10 times as many bases as minimally necessary, leave gaps in the sequence information that must be filled in manually, and have difficulty determining sequences with repetitive DNA. Thus, the goal of placing rapid sequencing techniques and improved mapping techniques in the hands of many researchers is yet to be achieved. New approaches are needed that eliminate the above-described limitations. SUMMARY OF THE INVENTION The present invention overcomes these and other drawbacks inherent in the prior art by providing methods and compositions for the analysis of nucleic acids, in particular for sequencing and mapping nucleic acids using double-stranded strand replacement reactions. These methods result in accurate sequencing reactions, in certain aspects due to very short extension reactions, and thus produce more useful sequence data from large templates, which overcome the problems inherent in single-stranded sequencing techniques. The present invention also provides new and powerful techniques for analyzing telomere length, telomere and subtelomeric sequence information, and quantitating the length and number of single-stranded overhangs present in telomeres. First provided are methods of creating or selecting one or more nucleic acid products that terminate with at least a first selected base. These terminated nucleic acid products and populations thereof may be used in a wide variety of embodiments, including, but not limited to, nucleic acid sequencing, nucleic acid mapping, and telomere analysis. The methods of creating one or more nucleic acid products that terminate with at least a first selected base generally comprise contacting at least a first substantially double stranded nucleic acid template comprising at least a first break on at least one strand with at least a first effective polymerase and a terminating composition comprising at least a first terminating nucleotide, the base of which corresponds to the selected base, under conditions effective to produce a nucleic acid product terminated at the selected base. The methods may first involve the synthesis, construction, creation or generation of the substantially double stranded nucleic acid template that comprises at least a first break on at least one strand. In which case, “contacting” the template with the effective polymerase and terminating composition forms the second part of the method. The term “template,” as used herein, refers to a nucleic acid that is to be acted upon, generally nucleic acid that is to be contacted or admixed with at least a first effective polymerase and at least a first nucleotide substrate composition under conditions effective to allow the incorporation of at least one more nucleotide or base into the nucleic acid to form a nucleic acid product. In many embodiments of the present invention, the nucleic acid product generated is a nucleic acid product that terminates with at least a first selected base. In some cases “template” means the target nucleic acids intended to be separated or sorted out from other nucleic acid sequences within a mixed population. “Substantially or essentially double stranded” nucleic acids or nucleic acid templates, as used herein, are generally nucleic acids that are double-stranded except for a proportionately small area or length of their overall sequence or length. The “proportionately small area” is an area lacking double stranded sequence integrity. The “proportionately small area lacking double stranded sequence integrity” may be as small as a single broken bond in only one strand of the nucleic acid, i.e., a break or “nick” within the double stranded nucleic acid molecule. The “proportionately small area lacking double stranded sequence integrity” may also be a gap produced within the double stranded nucleic acid molecule by excision or removal of at least one base or nucleotide. In these cases, the “substantially double stranded nucleic acids” may be described as being double-stranded except for a proportionately small area of single-stranded nucleic acid. “Proportionately small areas of single-stranded nucleic acids” are those corresponding to single-stranded areas, stretches or lengths of one, two, three, four, five, six, seven, eight, nine or about ten bases or nucleotides, as may be produced by creating a gap within the double stranded nucleic acid molecule by excision or removal of one, two, three, four, five, six, seven, eight, nine or about ten bases or nucleotides. In certain aspects of the invention, larger “proportionately small areas of single-stranded nucleic acids” are preferred, for example those corresponding to single-stranded areas, stretches or lengths of 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or about 100 bases or nucleotides, as may be produced by creating a gap within the double stranded nucleic acid molecule by excision or removal of 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or about 100 bases or nucleotides. In particular embodiments, even larger gaps may be created. The “proportionately small area of single-stranded nucleic acid” within a substantially double stranded nucleic acid may occur at any point within the substantially double stranded nucleic acid molecule or template, i.e., it may be terminal or integral. “Terminal portions of single-stranded nucleic acid” within a substantially double stranded nucleic acid are generally “overhangs”. Such “overhangs” may be naturally occurring overhangs, such as the area defined at the ends of telomeric DNA. “Overhangs” may also be engineered, i.e., created by the hand of man, using one or more of the techniques described herein and known to those of skill in the art. “Integral portions of single-stranded nucleic acid” within substantially double stranded nucleic acids, as used herein, will generally be engineered by the hand of man, again using one or more of the techniques described herein and known to those of skill in the art. The term “double stranded”, as applied to nucleic acids and nucleic acid templates, is generally reserved for nucleic acids that are completely double-stranded and that have no break, gap or single-stranded region. This allows “substantially double stranded” to be generally reserved for broken, nicked and/or gapped substantially double stranded nucleic acids and templates and substantially double stranded nucleic acids and templates that comprise at least a first single-stranded nucleic acid overhang. The templates for use in the invention may be in virtually any form, including covalently closed circular templates and linear templates. Both “native or natural” and “recombinant” nucleic acids and nucleic acid templates may be employed. “Recombinant nucleic acids”, as used herein, are generally nucleic acids that are comprised of segments of nucleic acids joined together by means of molecular biological techniques, i.e., by the hand of man. Although the nucleic acids for use in the methods will generally have been subjected to at least some isolation, and are thus not free from mans' intervention, “native and natural” nucleic acids and nucleic acid templates are intended to mean nucleic acids that have undergone less molecular biological manipulation and more correspond to the genomic DNA or fractions or fragments thereof. The templates may also be derived from any initial nucleic acid molecule, sample or source including, but not limited to, cloning vectors, viruses, plasmids cosmids, yeast artificial chromosomes (YACs), bacterial artificial chromosomes (BACs) and chromosomal and extrachromosomal nucleic acids isolated from eukaryotic organisms, including, but not limited to, yeast, Drosophila and mammals, including, but not limited to, mice, rabbits, sheep, rats, goats, cattle, pigs, and primates such as humans, chimpanzees and apes. In certain embodiments, the template may be created by cleavage from a precursor nucleic acid molecule. This generally involves treatment of the precursor molecule with enzymes that specifically cleave the nucleic acid at specific locations. Examples of such enzymes include, but are not limited to, restriction endonucleases, intron-encoded endonucleases, and DNA-based cleavage methods, such as triplex and hybrid formation methods, that rely on the specific hybridization of a nucleic acid segment to localize a cleavage agent to a specific location in the nucleic acid molecule. In other embodiments, the template may be created by amplifying the template from a precursor nucleic acid molecule or sample. The amplified templates generally include a region to be analyzed, i. e. sequenced, and can be relatively small, or quite large in various embodiments. In general, “amplification” may be considered as a particular example of nucleic acid replication involving template specificity. Amplification may be contrasted with non-specific template replication, i.e., replication that is template-dependent but not dependent on a specific template. “Template specificity” is here distinguished from fidelity of replication, i.e., synthesis of the proper polynucleotide sequence, and nucleotide (ribo- or deoxyribo-) specificity. “Template specificity” is frequently described in terms of “target” specificity. Target sequences are “targets” in the sense that they are desired to be separated or sorted out from other nucleic acids. Amplification techniques have been designed primarily for this “sorting out”. Amplification reactions generally require an initial nucleic acid sample or template, appropriate primers, an amplification enzyme and amplification reagents, such as deoxyribonucleotide triphosphates, buffers, and the like. In the sense of this application, a template for amplification (or “an amplification template”) refers to an initial nucleic acid sample or template, and does not refer to the “substantially double stranded nucleic acid template comprising at least a first break on at least one strand”. Therefore, as used herein, “an amplification template” is a “pre-template”. As used herein, the terms “amplifiable and amplified nucleic acids” are used in reference to any nucleic acid that may be amplified, or that has been amplified, by any amplification method including, but not limited to, PCR™, LCR, and isothermal amplification methods. Thus, the “substantially double stranded nucleic acid templates that comprise at least a first break on at least one strand” may be amplified nucleic acids or amplified nucleic acid products as well as templates for the methods of the invention. Widely used methods for amplifying nucleic acids are those that involve temperature cycling amplification, such as PCR™. Isothermal amplification methods such as strand displacement amplification are also routinely employed to amplify nucleic acids. All such amplification methods are appropriate to amplify “templates” for use in the invention from precursor nucleic acids or “pre-templates”. As used herein, the term “PCR™” (“polymerase chain reaction”) generally refers to methods for increasing the concentration of a segment of a template sequence in a mixture of genomic DNA without cloning or purification, as described in U.S. Pat. No. 4,683,195 and U.S. Pat. No. 4,683,202, each incorporated herein by reference. The process generally comprises introducing at least two oligonucleotide primers to a DNA mixture containing the desired template sequence, followed by a sequence of “thermal cycling” in the presence of a suitable DNA polymerase. The two primers are complementary to their respective strands of the double stranded template sequence. To effect amplification, the mixture is denatured and the primers then annealed to their complementary sequences within the template molecule. Following annealing, the primers are extended with a polymerase so as to form a new pair of complementary strands. In PCR, the steps of denaturation, primer annealing and polymerase extension are generally repeated many times, such that “denaturation, annealing and extension” constitute one “cycle”. Thus, “thermal cycling” means the execution of numerous “cycles” to obtain a high concentration of an amplified segment of the desired template sequence. As the desired amplified segments of the template sequence become the predominant sequences in the mixture, in terms of concentration, they are said to be “PCR™ amplified”. As used herein, the terms “PCR™ product”, “PCR™ fragment” and “amplification product” refer to the resultant mixture of compounds after two or more cycles of the PCR™ steps of denaturation, annealing and extension are complete. These terms encompass the case where there has been amplification of one or more segments of one or more target sequences. “PCR™ products and fragments” can naturally act as the broken, nicked or gapped substantially double stranded nucleic acid templates for use in the invention. Once a suitable or desired nucleic acid precursor, pre-template or sample composition has been obtained, a wide variety of substantially double stranded nucleic acid templates may be created for use in the claimed methods. In certain embodiments, even double stranded nucleic acid templates may be generated that comprise at least a first break substantially at the same position on both strands of the template. The most evident utility of this aspect of the invention is in producing nucleic acid fragments of a manageable size for further analysis, wherein such fragmentation is required. In certain of the preferred sequencing and mapping embodiments, the substantially double stranded nucleic acid template will comprise at least a first break on only one of the two strands. This is advantageous in that the product or products are generated from the same strand, leading to more direct and rapid analysis. In certain of the sequencing and mapping aspects of the invention, having the strand replacement start at a defined point on one strand is advantageous, particularly where analysis of the size of the products of the reaction, particularly the differential size of a population of products, is necessary. However, in a most general sense, creating a break on only one strand operably means that only one break is present in the region or target region of the individual nucleic acid molecule being analyzed or utilized. The target region is defined as a region of sufficient length to yield useful information and yet to allow the required volume of data to be generated in relation to the original nucleic acid subjected to the analysis. Thus, breaks at a distant region of the same nucleic acid molecule, outside of the target region, or breaks in the same general target region of a population of nucleic acid molecules, can exist and yet the target will still be considered to contain a “functional break” on only one strand. In any event, in most aspects of the invention, the presence of additional breaks or nicks is not a drawback, so long as a 3′ hydroxyl group can be generated in the presence of a template strand that can support the incorporation of at least one complementary base. The presence of multiple breaks on both strands is either useful, as one can initiate synthesis at a plurality of points as only the “first-encountered” break forms the functional break for extension and/or termination, or non-functional, and thus irrelevant, in most aspects of the invention. For example, although synthesis products may be produced from breaks on both strands, utilizing the labeling techniques in conjunction with the isolation or immobilization techniques as disclosed herein products from only one strand and closest to the detectable label are detected in the final analysis step, thus eliminating the requirement for a break on only one strand in the most rigid sense. In general, the complexity of the nicking or breaking reaction is directly correlated with the complexity of the labeling and/or isolation or immobilization procedures. In aspects wherein a nick or break is generated at a single position in a population of identical templates, only a single detectable label is required to analyze the products of the extending and/or terminating reaction. The presence of additional breaks or nicks is made most useful when employed with additional labels and/or the isolation of a subset of the nucleic acid products prior to analysis. Although by no means limiting, in substantially double stranded nucleic acid templates that comprise at least a first integral break or gap on only one strand, it is convenient to identify the intact or “unbroken” strand as the “template strand”, and the strand that comprises at least a first integral break or gap as the “non-template strand”. In those methods of the invention that encompass sequencing, the template strand will generally act as the guideline for the incorporation of one or more complementary bases or nucleotides into the “non-template strand”, which is herein defined as the “extension of the non-template strand”. The “extension” of the non-template strand may be an extension by a single base or nucleotide only, in which case the “extension” is inherently an “extension and termination”. The single base or nucleotide incorporated into the non-template strand is thus a “terminating base or nucleotide”. This allows the broken, nicked or gapped strand to also be referred to as “the terminated strand”. Alternatively, the “extension” of the non-template strand may be an extension by two, three or more, or a plurality of, bases or nucleotides, and/or an extension to create a population of extended non-template strands each including a different number of incorporated bases or nucleotides. In these cases, “termination” is not co-extensive with “extension”, and termination may even be delayed until after the incorporation of a significant number of “extending” bases or nucleotides. Thus, the broken, nicked or gapped strand that formed the starting point for the two, three or multiple base extension may also be termed “the synthesized strand”. In contrast, in substantially double stranded nucleic acid templates that comprise a terminal single-stranded portion or “overhang”, it may be more convenient to identify the single-stranded overhang portion as the template strand. This is essentially because the art uses an existing “hybridizable” nucleic acid portion as a “template”, e.g., in the sense that a sufficiently complementary probe or primer can hybridize to the template. As used herein, the term “probe” refers to an oligonucleotide, i.e., a contiguous sequence of nucleotides, whether occurring naturally as in a purified restriction digest or produced synthetically, recombinantly or by PCR™ amplification, that is capable of hybridizing to a nucleic acid of interest or portion thereof. Although probes may be single-stranded or double-stranded, the hybridizing probe described above in reference to binding to a nucleic acid overhang will generally be single-stranded. Probes are often labeled with a detectable label or “reporter molecule” that is detectable in a detection system, including, but not limited to fluorescent, enzyme (e.g., ELISA), radioactive, and luminescent systems. The term “primer”, as used herein refers to an oligonucleotide, whether occurring naturally as in a purified restriction digest or produced synthetically, that is capable of acting as a point of initiation of nucleic acid synthesis when placed under conditions in which the synthesis of a primer extension product that is complementary to a nucleic acid strand of interest is induced, e.g., in the presence of nucleotides and an inducing agent such as DNA polymerase and at a suitable temperature and pH. A primer must be sufficiently long to prime the synthesis of extension products in the presence of the inducing agent The exact length of an effective primer depends on factors such as temperature of extension, source of primer and the particular extension method. Primers are preferably single stranded for maximum efficiency in amplification (but may be double stranded if first treated to separate the strands before use in preparing extension products). Primers are often preferably oligodeoxyribonucleotides. The invention further provides various methods for generating the substantially double stranded, broken nucleic acid templates. Certain of the template-generation methods are generic to the creation of various types of template sought. For example, methods are disclosed that are capable of creating substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken. Equally, distinct methods are provided for creating substantially double stranded nucleic acid templates in which both template strands are broken versus those for creating substantially double stranded nucleic acid templates in which only one of the template strands is broken. Enzymatic methods are provided that are universally applicable to creating substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken. Such methods generally comprise creating the template by contacting a double-stranded or substantially double-stranded nucleic acid with a combined effective amount of at least a first and second breaking enzyme combination. A “combined effective amount of at least a first and second breaking enzyme combination” is a combined amount of at least a first and second enzyme effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first break. Examples of broadly effective “enzymatic breaking combinations” are uracil DNA glycosylase in combination with an effectively matched endonuclease, such as endonuclease IV or endonuclease V. In light of the present disclosure, those of ordinary skill in the art will understand that the use of a uracil DNA glycosylase-endonuclease combination is predicated on the prior incorporation of at least a first uracil base or residue into the nucleic acid molecule that is to form the template. Accordingly, in certain embodiments, the invention provides for the creation of a template by generating a double-stranded or substantially double-stranded nucleic acid molecule comprising at least a first uracil base or residue and contacting the uracil-containing nucleic acid molecule with a combined effective amount of a first, uracil DNA glycosylase enzyme and a second, endonuclease IV enzyme or endonuclease V enzyme. The use of endonuclease V in the combination is generally preferred. A “combined effective amount of a first, uracil DNA glycosylase enzyme and a second, endonuclease IV or V enzyme” is a combined amount of the enzymes effective to create a substantially double stranded nucleic acid template comprising at least a first gap corresponding in position to the position of the at least a first uracil base or residue incorporated into the uracil-containing nucleic acid molecule. The incorporation of at least a first uracil base or residue into a double-stranded or substantially double-stranded nucleic acid molecule is generally achieved by incorporation of a dUTP residue in the nucleic acid synthesis reaction. In certain aspects of the invention it is desired to incorporate a single uracil base or residue into a specific location near the 5′ end of the nucleic acid template. In a general sense, this may be accomplished by methods comprising contacting a precursor molecule with at least a first and a second primer that amplify the template when used in conjunction with a polymerase chain reaction, wherein at least one of the first or second primers comprises at least a first uracil base, and conducting a polymerase chain reaction to create an amplified template containing a single uracil residue corresponding to the location of the uracil base in the uracil-containing primer. In certain aspects, both primers contain uracil, to produce an amplified template that contains a uracil residue near the 5′ end of both strands. In other embodiments, dUTP will be used in the synthesis of the template strand, thus incorporating multiple uracil residues into the template. Incorporation of at least a first uracil base or residue only into one of the strands of the nucleic acid molecule allows for the subsequent generation of a substantially double stranded nucleic acid template in which only one of the template strands is broken, whereas incorporation of at least a first uracil base or residue into each of the strands of the nucleic acid molecule allows for the subsequent generation of a substantially double stranded nucleic acid template in which both of the template strands are broken. Certain chemical cleavage compositions are also appropriate for creating substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken. Such methods generally comprise creating the template by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of an appropriate chemically-based nucleic acid cleavage composition. An “effective amount of an appropriate chemically-based nucleic acid cleavage composition” is an amount of the composition effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first break. In yet further embodiments, substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken may be created by contacting a substantially double-stranded nucleic acid with an effective amount of at least a first appropriate nuclease enzyme. An “effective amount of at least a first appropriate nuclease enzyme” is an amount of the nuclease enzyme effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first break. In different embodiments, the invention provides methods for making and using substantially double stranded nucleic acid templates in which the one or more breaks or gaps are either located at a specific point or points along the nucleic acid template, or in which the one or more breaks or gaps are located at a random location or locations along the nucleic acid template. These may be referred to as “specifically broken, nicked or gapped templates” and “randomly broken, nicked or gapped templates”, respectively. The methods for generating the specifically and randomly manipulated templates are generally different in principle and execution, although both nucleases and non-nuclease-based chemical or biological components may be used in various of the methods. In certain embodiments, a substantially double stranded nucleic acid template comprising at least a first break or gap at a specific point on at least one strand of the template is created by contacting a double stranded or substantially double-stranded nucleic acid with an effective amount of at least a first specific nuclease enzyme. Exemplary specific nuclease enzymes are f1 endonuclease, fd endonuclease or a restriction endonuclease. A preferred specific nuclease enzyme is f1 endonuclease. An “effective amount of at least a first specific nuclease enzyme” is an amount of the nuclease enzyme effective to create a substantially double stranded nucleic acid template that comprises at least a first break or gap at a specific point on at least one strand of the template. In other embodiments, the specific-type template is created by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of an appropriate specific chemical cleavage composition. An exemplary embodiment is wherein the specific chemical cleavage composition comprises a nucleic acid segment, such as a hybrid or triple helix forming composition, that is linked to a metal ion chelating agent The chelating agent binds a metal ion, and in the presence of a peroxide and a reducing agent, produces a hydroxyl radical that can nick or break a nucleic acid. The specificity of the cleavage is provided from the nucleic acid segment, which only hybridizes to or forms a triple helix at a specific location in the nucleic acid molecule to be broken or nicked. In certain cases, the hydroxyl radicals produced can diffuse, and thus a small region is broken or nicked, producing a gap. An “effective amount of at least a first specific chemical cleavage or triple helix-forming composition” is an amount of the composition effective to create a substantially double stranded nucleic acid template that comprises at least a first break or gap at a specific point on at least one strand of the template. For use in certain embodiments, particularly the random break incorporation and random break degradation sequencing embodiments, the creation of a substantially double stranded nucleic acid template comprising at least a first random break or gap on at least one strand will be preferred. Templates with one or more breaks or nicks located at one or more random points or locations along the nucleic acid template are termed “randomly nicked templates”. Suitable processes for creating such randomly nicked templates, or populations thereof, are collectively termed “random nicking”. “Random nicking” generally refers to a process or processes effective to generate a substantially double stranded nucleic acid template that comprises at least a first broken bond located at at least a first random position within the sugar-phosphate backbone of at least one of the two strands of the nucleic acid template. As used herein, a “randomly nicked template” is intended to mean “at least a randomly nicked template”. This signifies that at least one randomly-located broken bond is present, which broken bond may form the starting point or “substrate” for further manipulations, e.g., to convert the nick into a gap. A process of random nicking that creates at least a first randomly positioned broken bond in a strand of the template may then be extended to create a gap at that random point or position by excising at least the first base or nucleotide proximal to the broken bond. This then becomes a process of “random gapping” effective to prepare a “random gap template”, or a population thereof, comprising one or more gaps of at least a nucleotide in length positioned randomly within the nucleic acid template. In certain embodiments, particularly certain mapping and sequencing aspects, the creation of a substantially double stranded nucleic acid template comprising at least a first random break or gap on only one strand will be preferred. This is generally for ease of analysis of the information generated from a strand replacement reaction, but also has advantages as detailed above. Suitable methods that may be adapted to create a substantially double stranded nucleic acid template comprising at least a first random break or gap on at least one, or only one, strand are provided herein. The optimization of the random nicking methods to mono-stranded or dual-stranded nicking is generally based upon the correlation between the breaking or nicking agent, enzyme, chemical or composition and the time and conditions used to produce the break or nick. Agents that produce a given break or nick under one set of conditions, can produce a completely different break under different conditions. For example, a breaking or nicking agent that produces a single break or nick under one reaction condition, can in certain embodiments produce a plurality of breaks or nicks under a second, distinct reaction condition. Thus, the double stranded nucleic acid template comprising at least a first random break or gap on at least one, or only one, strand that is produced depends not only on the breaking or nicking agent used, but the conditions used to conduct the breaking or nicking reaction. In one embodiment, the at least randomly nicked template is created by generating a double-stranded or substantially double-stranded nucleic acid comprising at least a first randomly positioned exonuclease-resistant nucleotide, and contacting the nucleic acid with an effective amount of an exonuclease. Exemplary exonuclease-resistant nucleotides include, but are not limited to deoxyribonucleotide phosphorothioates and deoxyribonucleotide boranophosphates. The preferred effectively matched exonuclease is exonuclease III. In these embodiments, an “effective amount of an exonuclease” is an amount of the exonuclease effective to degrade the strand containing the exonuclease-resistant base to the position of the resistant base. The incorporation of at least a first randomly positioned exonuclease-resistant nucleotide into a double-stranded or substantially double-stranded nucleic acid molecule is generally achieved by utilizing extendable deoxynucleotides comprising the exonuclease-resistant feature during the synthesis of the nucleic acid precursor or template. The amount of exonuclease-resistant incorporated into the nucleic acid template can be controlled by adjusting the ratio of the extendable deoxynucleotides with and without the exonuclease-resistant feature used in the synthesis reaction. In alternate aspects of the present invention, the at least randomly nicked template is created by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of at least a first randomly-nicking or -breaking nuclease enzyme. Exemplary randomly-breaking nuclease enzymes are deoxyribonuclease I and CviJI restriction endonuclease. An “effective amount of at least a first randomly-nicking or -breaking nuclease enzyme” is an amount of the nuclease enzyme effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first randomly located broken bond within the template backbone. In yet a further aspect of the invention, the at least randomly nicked template is created by contacting a double-stranded or substantially double-stranded nucleic acid with a combined effective amount of at least a first and second randomly-breaking nuclease enzyme combination. Exemplary randomly-breaking enzymes for use as the first or second nuclease enzymes are the frequent-cutting restriction endonucleases Tsp509I, MaeII, TaiI, AluI, CviJI, NlaIII, MspI, HpaII, BstUI, BfaI, DpnII, MboI, Sau3AI, DpnI, ChaI, HinPI, HhaI, HaeIII, Csp6I, RsaI, TaqI and MseI, which may be used in any combination. A “combined effective amount of at least a first and second randomly-breaking nuclease enzyme combination or frequent-cutting restriction endonuclease combination” is a combined amount of the nuclease enzymes effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first randomly located broken bond within the template backbone. As used herein, the terms “nucleases”, “restriction endonucleases” and “restriction enzymes” refer to enzymes, generally bacterial enzymes, that cut nucleic acids. Mostly, the enzymes cut nucleic acids at or near specific nucleotide sequences, but certain enzymes, such as DNAase I, produce essentially random cuts or breaks. Further embodiments of randomly-nicked template creation rely on contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of a randomly-nicking or -breaking chemical cleavage composition. Throughout the variety of randomly-nicking or -breaking chemical cleavage compositions that may be employed, an “effective amount” is an amount of the chemical cleavage composition effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first randomly located broken bond within the template backbone. In preferred embodiments, the random chemical cleavage compositions will comprise or react to produce a hydroxyl radical. Certain suitable randomly-breaking chemical cleavage compositions comprise a chelating agent, a metal ion, a reducing agent and a peroxide, as exemplified by compositions that comprise EDTA, an Fe2+ ion, sodium ascorbate and hydrogen peroxide. In other embodiments, the randomly-breaking chemical cleavage composition comprises a compound, generally a dye, that produces a hydroxyl radical upon contact with a defined or specified wavelength(s) of light. Randomly-nicked templates may also be created by effectively irradiating with gamma irradiation, i.e., by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of gamma irradiation. Effective application of one or more mechanical breaking processes may also be employed to create the randomly broken or nicked templates. Exemplary mechanical breaking processes include subjecting double-stranded or substantially double-stranded nucleic acids to effective amounts of: hydrodynamic forces, sonication, nebulization and/or freezing and thawing. In the methods of creating nucleic acid products that terminate with at least a first selected base, the at least nicked nucleic acid template is contacted with at least a first effective polymerase and at least a first effective terminating composition comprising at least a first terminating nucleotide, wherein the base of the terminating nucleotide corresponds to the selected base desired for nucleic acid incorporation and termination, “under conditions effective to produce a nucleic acid product terminated at the selected base”. “Under conditions effective to produce a nucleic acid product terminated at the selected base” means that the conditions are effective to permit at least one round of nucleotide extension and termination, thus incorporating at least one additional base or nucleotide (the selected base or corresponding nucleotide) into the nucleic acid product The “effective conditions” are thus “product-generating conditions”, “nucleotide extension and termination-permissive conditions” or “at least nucleotide extending and terminating conditions”. Fundamental aspects of the “effective, product-generating conditions” include conditions permissive or favorable to the necessary biological reactions, i.e., appropriate conditions of temperature, pH, ionic strength, and the like. The term “under conditions effective to produce a nucleic acid product terminated at the selected base” also means, in and of itself, “under conditions suitable and for a period of time effective to produce a nucleic acid product terminated at the selected base”. According to the intended use(s) of the selected base-terminated nucleic acid products, or populations thereof, the “effective, product-generating conditions and times” may also be termed “effective nucleic acid sequencing conditions” and/or “effective nucleic acid mapping conditions”. The “effective, product-generating conditions and times” will vary depending on the type of nucleic acid product or products that one wishes to generate: e.g., products in which the at least nicked nucleic acid template strand is extended with only a single base or nucleotide; or with only two selected bases or nucleotides; or with only three selected bases or nucleotides; or in which the at least nicked nucleic acid template strand is extended with a plurality of bases or nucleotides; and/or in which the at least nicked nucleic acid template is used to prime the synthesis of a population of extended nucleic acid strands, each terminated at a different point Inherent in the term “effective, product-generating conditions” is the concept that the “at least a first effective polymerase” will be a polymerase that is effective to generate the type of nucleic acid product or products desired under the extending or polymerizing conditions applied Equally, the “at least a first effective terminating composition” will be a terminating composition effective to generate the type of terminated nucleic acid product or products desired under the termination conditions applied. Also inherent in the term “effective, product-generating conditions” is the concept that the “effective polymerase” is a polymerase that is effective to act on the precise type of nick, break or gap in the template under the extending or polymerizing conditions applied. This means that the polymerase has synthetic activity under the chosen conditions, i.e., the polymerase is capable of catalyzing the addition of the desired type and number of bases or nucleotides using the nick, break or gap in the template as the “priming substrate”. The type of nick, break or gap in the template thus forms an “effective matched pair” with the selected polymerase. DNA molecules have “5′ and 3′ ends”, meaning that mononucleotides have been reacted to make oligonucleotides or polynucleotides in a manner such that the 5′ phosphate of one mononucleotide pentose ring is attached to the 3′ oxygen (from the original hydroxyl) of its neighbor in one direction via a phosphodiester linkage. Therefore, an end of an oligonucleotide or polynucleotide is referred to as the “5′ end” if its 5′ phosphate is not linked to the 3′ oxygen of a mononucleotide pentose ring and as the “3′ end” if its 3′ oxygen is not linked to a 5′ phosphate of a subsequent mononucleotide pentose ring. As used herein, a nucleic acid sequence, even if internal to a larger oligonucleotide or polynucleotide, may also be said to have 5′ and 3′ ends. In either a linear or circular DNA molecule, discrete elements are referred to as being “upstream” or 5′ of the “downstream” or 3′ elements. This terminology reflects the fact that transcription proceeds in a 5′ to 3′ fashion along the DNA strand. In embodiments where the break in the substantially double stranded nucleic acid template is a nick that comprises, or is reacted to comprise, a 3′ hydroxyl group, the effective polymerase will generally either have 5′ to 3′ exonuclease activity or strand displacement activity, or both. Effective polymerases in these categories include, for example, E. coli DNA polymerase I, Taq DNA polymerase, S. pneumoniae DNA polymerase I, Tfl DNA polymerase, D. radiodurans DNA polymerase I, Tth DNA polymerase, Tth XL DNA polymerase, M. tuberculosis DNA polymerase I, M. thermoautotrophicum DNA polymerase I, Herpes simplex-1 DNA polymerase, E. coli DNA polymerase I Klenow fragment, vent DNA polymerase, thermosequenase and wild-type or modified T7 DNA polymerases. In preferred embodiments, the effective polymerase will be E. coli DNA polymerase I, M. tuberculosis DNA polymerase I or Taq DNA polymerase. Where the break in the substantially double stranded nucleic acid template is a gap of at least a base or nucleotide in length that comprises, or is reacted to comprise, a 3′ hydroxyl group, the range of effective polymerases that may be used is even broader. In such aspects, the effective polymerase may be, for example, E. coli DNA polymerase I, Taq DNA polymerase, S. pneumoniae DNA polymerase I, Tfl DNA polymerase, D. radiodurans DNA polymerase I, Tth DNA polymerase, Tth XL DNA polymerase, M. tuberculosis DNA polymerase I, M. thermoautotrophicum DNA polymerase I, Herpes simplex-1 DNA polymerase, E. coli DNA polymerase I Klenow fragment, T4 DNA polymerase, vent DNA polymerase, thermosequenase or a wild-type or modified T7 DNA polymerase. In preferred aspects, the effective polymerase will be E. coli DNA polymerase I, M. tuberculosis DNA polymerase I, Taq DNA polymerase or T4 DNA polymerase. In those embodiments in which either the nicked or broken template does not initially comprise a 3′ hydroxyl group, such as when the template is generated by hydroxyl radicals (in certain instances) or certain physical or mechanical processes, the nicked template may still be manipulated or reacted to comprise the desired 3′ hydroxyl group. Methods for achieving this generally involve “conditioning” the non-3′ hydroxyl group containing position. In a preferred aspect of the invention, the “conditioning” involves exonuclease III treatment to remove the base or position lacking a 3′ hydroxyl group, leaving a 3′ hydroxyl group as a product of the removal reaction. Various methods are also available for terminating the nucleic acid extension to produce the one or more terminated nucleic acid products. For example, the terminating composition may simply comprise a terminating dideoxynucleotide triphosphate, the base of which corresponds to the selected base. Extension with a single base and termination thus occur simultaneously as the dideoxynucleotide triphosphate in incorporated into the template at the break or nick, preventing further addition or extension due to the absence of an available —OH group. In other embodiments, the terminating composition comprises a terminating deoxynucleotide triphosphate, the base of which corresponds to the selected base. Extension of the nicked strand with a single type of base and termination with that base still occur essentially simultaneously as only one type of deoxynucleotide triphosphate is available for incorporation into the template at the break or nick (with the number of bases incorporated into the nicked strand depending on the number of complementary bases in the corresponding or template strand), thus preventing further addition or extension due to the absence of other nucleotides. Where detection of the nucleic acid product or products is desired, the product or products will preferably comprise a detectable label or isolation tag. Inherent in the term “under conditions effective to produce a nucleic acid product terminated at the selected base” is the concept that the “effective terminating composition” is effective to incorporate a detectable label into the nucleic acid product or products under the terminating conditions applied, should such labeling be necessary or preferable for subsequent detection or execution of related sequencing or mapping techniques. The type of terminating composition and the type of label or tag in the nucleic acid product or products thus also form an “effective matched pair”. Accordingly, in any of the methods of the invention, the at least a first terminating nucleotide or nucleotides may comprise a detectable label or an isolation tag that is incorporated into the nucleic acid product or products. In certain aspects, the substantially double stranded nucleic acid template may comprise a detectable label or isolation tag incorporated into the template, and hence into the subsequent nucleic acid product or products, at a point other than the termination point. In other aspects, both the template and the terminating nucleotide or nucleotides may each comprise a detectable label or an isolation tag. Preferred aspects of the invention require the detection of the terminated nucleic acid product or products generated by the foregoing methods. In certain embodiments, the nucleic acid product or products will be separated, e.g., by electrophoresis, mass spectroscopy, FPLC or HPLC, prior to detection. The nucleic acid product or products will generally comprise a detectable label, and the nucleic acid product or products are detected by detecting the label. In certain aspects, the nucleic acid product or products will comprises an isolation tag, and the nucleic acid product or products are purified using the isolation tag, optionally prior to more precise detection or differentiation techniques. Suitable detectable labels and isolation tags are exemplified by radioactive, enzymatic and fluorescent labels; and biotin, avidin and streptavidin isolation tags. Detection is generally integral to the use of the invention in methods for sequencing nucleic acids, wherein the methods comprise detecting the nucleic acid product or products under conditions effective to determine the nucleic acid sequence of at least a portion of the nucleic acid. In certain embodiments, the introduction or incorporation of the at least a first selected base at the break or nick in the template allows for direct nucleic acid sequencing. These methods generally rely on the generation of a population of nucleic acid products randomly terminated at four selected bases, as exemplified by: a) creating a population of substantially double-stranded nucleic acid templates from a nucleic acid molecule to be sequenced, each of the templates comprising at least a first random break, preferably only on one strand; b) contacting the population of templates with an effective polymerase and a terminating composition comprising four distinct labeled or tagged terminating nucleotides, under conditions effective to produce a population of terminated nucleic acid products randomly terminated at four selected bases; c) detecting the population of randomly terminated nucleic acid products under conditions effective to determine the nucleic acid sequence of at least a portion of the original nucleic acid molecule. In certain embodiments, the population of templates is contacted with the terminating composition in four distinct reactions, or wells, each of the reactions comprising only one of the four distinct labeled or tagged terminating nucleotides. In other embodiments, the population of templates is contacted with the terminating composition in a single reaction, or well, wherein each of the four terminating nucleotides comprises a distinct, fluorescent label. In further sequencing embodiments, the introduction or incorporation of the at least a first selected base at the break or nick in the template acts as a primer for other, non-direct nucleic acid sequencing methods. An exemplary method is “Sanger”-based sequencing, originating at the nick or gap in the double-stranded template. Such a method may comprise: a) creating at least a first substantially double-stranded nucleic acid template from the nucleic acid molecule to be sequenced, the template comprising at least a first random break, preferably only on one strand; b) contacting the at least a first template with an effective polymerase and at least a first extending and terminating composition comprising four extending deoxynucleotide triphosphates and a labeled or tagged terminating dideoxynucleotide triphosphate, under conditions effective to produce a population of terminated nucleic acid products, each originating from the random break; c) detecting the terminated nucleic acid products under conditions effective to determine the nucleic acid sequence of at least a portion of the original nucleic acid molecule. Again, the four terminating bases may comprise distinct fluorescent labels. In addition to “Sanger-like” methods, still further analytical and sequencing methods also require the introduction or incorporation of at least one further base at the break or gap in the template in addition to the selected base. Thus, a first and a second selected base may be incorporated; or this may be described as incorporating a “specified base” in addition to the selected base. Production of a nucleic acid product comprising at least one specified base prior to termination at the selected base requires contacting the template with an effective polymerase and extending and terminating composition, wherein the extending composition comprises the extending specified base. These methods may be further defined as methods for identifying a selected dinucleotide sequence in the template strand of the nucleic acid template, the dinucleotide sequence being the complement of the specified and selected base incorporated into the non-template, or synthesized strand that originally contained the nick or gap. Such methods comprise: a) blocking the at least nicked template by contacting the at least nicked template with a first blocking composition comprising the three dideoxynucleotide triphosphates that do not contain the specified base, to create a blocked template; b) removing the first blocking composition from contact with the blocked template; c) contacting the blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the specified base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the selected base, under conditions effective to produce a nucleic acid product terminating with a dinucleotide sequence of the specified and selected base; and d) detecting the nucleic acid product under conditions effective to identify the selected dinucleotide sequence in the template strand of the nucleic acid template. Defining the selected dinucleotide sequence as a first and second base in a template strand of a nucleic acid template, such methods are defined as comprising: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base, to create a blocked template; b) removing the first blocking composition from contact with the blocked template; c) contacting the blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the second base, under conditions effective to produce a nucleic acid product terminating with a dinucleotide sequence complementary to the first and second base; and d) detecting the nucleic acid product under conditions effective to identify the selected dinucleotide sequence in the nucleic acid template. In such methods, step (c) may be conducted as a single extending and terminating step, comprising contacting with a composition that comprises both the extending deoxynucleotide triphosphate and the terminating dideoxynucleotide triphosphate. Step (c) may also be conducted as at least two distinct extending and terminating steps, comprising first contacting the template with an extending composition that comprises the extending deoxynucleotide triphosphate, and then contacting the template with a distinct terminating composition that comprises the terminating dideoxynucleotide triphosphate. Step (c) may comprise, in sequence, contacting the template with an extending composition that comprises the extending deoxynucleotide triphosphate, removing the extending composition from contact with the template, and contacting the template with a distinct terminating composition that comprises the terminating dideoxynucleotide triphosphate. The non-Sanger analytical and sequencing methods may also require the introduction or incorporation of at least two further bases at the break or gap in the template in addition to the selected base. Thus, the nicked template is subjecting to a series of blocking and washing, and extending and washing reactions prior to contact with the terminating composition, thereby producing an extended nucleic acid product comprising two, three or a series of additional bases preceding the selected, terminating base. Such methods allow for the identification of a selected trinucleotide sequence in a nucleic acid template, the trinucleotide sequence being the complement of the first and second specified bases and the selected base, the method comprising: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the first specified base, to create a first-blocked template; b) removing the first blocking composition from contact with the first-blocked template; c) extending the first-blocked template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the first specified base, to create a first-extended template; d) removing the first extending composition from contact with the first-extended template; e) blocking the first-extended template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the second specified base to create a second-blocked template; f) removing the second blocking composition from contact with the second-blocked template; g) contacting the second-blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the second specified base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the selected base, under conditions effective to produce a nucleic acid product terminating with a trinucleotide sequence of the first and second specified bases and the selected base; and h) detecting the nucleic acid product under conditions effective to identify a selected trinucleotide sequence in the nucleic acid sample. Defining the selected trinucleotide sequence as a first, second and third base in a template strand of a nucleic acid template, the foregoing methods are defined as comprising: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base to create a first-blocked template; b) removing the first blocking composition from contact with the first-blocked template; c) extending the first-blocked template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base to create a first-extended template; d) removing the first extending composition from contact with the first-extended template; e) blocking the first-extended template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base to create a second-blocked template; f) removing the second blocking composition from contact with the second-blocked template; g) contacting the second-blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the complement of the second base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the third base, under conditions effective to produce a nucleic acid product terminating with a trinucleotide sequence complementary to the first, second and third bases; and h) detecting the nucleic acid product under conditions effective to identify the selected trinucleotide sequence in the nucleic acid sample. These methods may comprise: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base to create a first-blocked template; b) removing the first blocking composition from contact with the first-blocked template; c) extending the first-blocked template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base to create a first-extended template; d) removing the first extending composition from contact with the first-extended template; e) blocking the first-extended template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base to create a second-blocked template; f) removing the second blocking composition from contact with the second-blocked template; g) further extending the second-blocked template by contacting with a second extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the second base to create a second-extended template; h) terminating the reaction by contacting the second-extended template with a terminating composition comprising a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the third base, under conditions effective to produce a nucleic acid product terminating with a trinucleotide sequence complementary to the first, second and third bases; and i) detecting the nucleic acid product under conditions effective to identify a selected trinucleotide sequence in the nucleic acid sample. The methods of di- and tri-nucleotide identification may further be used as methods for sequencing a nucleic acid molecule by identifying selected di- or tri-nucleotide sequences, wherein the identification of the selected di- or tri-nucleotide sequences is followed by the compilation of the identified di- or tri-nucleotide sequences to determine the contiguous nucleic acid sequence of at least a portion of the nucleic acid molecule. The methods of selecting at least a first nucleic acid product terminated with at least a first selected base generally comprise creating a substantially double stranded nucleic acid template comprising at least a first break on at least one strand, and contacting the template with an effective polymerase and a terminating composition comprising at least a first terminating nucleotide, wherein the base of the terminating nucleotide corresponding to the selected base, under conditions effective to produce a nucleic acid product terminated at a selected base, or an effective polymerase and an extending composition under conditions effective to produce a fully extended product only from a template that terminates at the selected base. The methods may first involve creating a substantially double stranded nucleic acid template comprising at least a first random double stranded break. The methods may be further defined as methods for determining the position of at least a first selected dinucleotide sequence of at least a first and at least a second base in at least a first nucleic acid template. The methods may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a 3′ end comprising a hydroxyl group; b) blocking the template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base; c) removing the first blocking composition from contact with the template; d) extending the template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base; e) removing the first extending composition from contact with the template; f) blocking the template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base; g) removing the second blocking composition from contact with the template; h) contacting the template with at least a second extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a dinucleotide sequence complementary to the first and second bases; and i) detecting the nucleic acid product under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid sample. The methods of determining the position of at least a first selected dinucleotide sequence comprising at least a first base and a second base in one or more nucleic acid templates may alternatively comprise: a) attaching a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the template at a temperature effective to disassociate the lower strand of the adaptor; c) annealing a single-stranded oligonucleotide comprising a 3′ hydroxyl group to the template, the first oligonucleotide comprising the same nucleotide sequence as the lower strand plus a first additional 3′ base complementary to the first base and a second additional 3′ base complementary to the second base; d) contacting the template with an extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a dinucleotide sequence complementary to the first and second bases; and e) detecting the nucleic acid product under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid sample. Optionally, the methods of determining the position of at least a first selected dinucleotide sequence comprising at least a first base and a second base in at least a fist nucleic acid template may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the ligated double-stranded nucleic acid segment at a temperature effective to disassociate the lower strand of the adaptor, c) annealing a first single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the first oligonucleotide comprising the same nucleotide sequence as the lower strand; d) blocking the templates by contacting with a first blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the first base; e) removing the first blocking composition from contact with the templates; f) contacting the templates with at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; g) heating the templates at a temperature effective to disassociate the first single stranded oligonucleotide; h) annealing a second single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the first single-stranded oligonucleotide plus a first additional 3′ base complementary to the first base; i) blocking the templates by contacting with a second blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the second base; j) removing the second blocking composition from contact with the templates; k) contacting the templates with the at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; l) heating the templates at a temperature effective to disassociate the second single stranded oligonucleotide; m) annealing a third single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the second single-stranded oligonucleotide plus a second additional 3′ base complementary to the second base; n) contacting the templates with at least a second extending and labeling composition comprising four deoxynucleotide triphosphates, at least one of which comprises a detectable label, under conditions effective to completely extend the non-template strand; o) contacting the templates with at least a first degrading composition under conditions effective to degrade the non-template strands containing a uracil base; and p) detecting the nucleic acid products under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid templates. The methods may also be further defined as methods for determining the position of at least a first selected trinucleotide sequence of at least a first, second and third base in one or more nucleic acid templates. The methods may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a 3′ end comprising a hydroxyl group; b) blocking the template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base; c) removing the first blocking composition from contact with the template; d) extending the template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base; e) removing the first extending composition from contact with the template; f) blocking the template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base; g) removing the second blocking composition from contact with the template; h) extending the template by contacting with a second extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the second base; i) removing the second extending composition from contact with the template; j) blocking the template by contacting with a third blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the third base; k) removing the third blocking composition from contact with the template; l) contacting the template with at least a third extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a trinucleotide sequence complementary to the first, second and third bases; and m) detecting the nucleic acid product under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid sample. The methods of determining the position of at least a first selected trinucleotide sequence comprising at least a first base, a second base and a third base in at least a first nucleic acid template may optionally comprise: a) attaching a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the template at a temperature effective to disassociate the lower strand of the adaptor, c) annealing a single-stranded oligonucleotide comprising a 3′ hydroxyl group to the template, the first oligonucleotide comprising the same nucleotide sequence as the lower strand plus a first additional 3′ base complementary to the first base, a second additional 3′ base complementary to the second base and a third additional 3′ base complementary to the third base; d) contacting the template with an extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a trinucleotide sequence complementary to the first, second and third bases; and e) detecting the nucleic acid product under conditions effective to determine the position of the selected trinucleotide sequence in the nucleic acid sample. Alternatively, the methods of determining the position of at least a first selected trinucleotide sequence comprising at least a first base, a second base and a third base in one or more nucleic acid templates may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the ligated double-stranded nucleic acid segment at a temperature effective to disassociate the lower strand of the adaptor, c) annealing a first single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the first oligonucleotide comprising the same nucleotide sequence as the lower strand; d) blocking the templates by contacting with a first blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the first base; e) removing the first blocking composition from contact with the templates; f) contacting the templates with at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; g) heating the templates at a temperature effective to disassociate the first single stranded oligonucleotide; h) annealing a second single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the first single-stranded oligonucleotide plus a first additional 3′ base complementary to the first base; i) blocking the templates by contacting with a second blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the second base; j) removing the second blocking composition from contact with the templates; k) contacting the templates with the at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; l) heating the templates at a temperature effective to disassociate the second single stranded oligonucleotide; m) annealing a third single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the second single-stranded oligonucleotide plus a second additional 3′ base complementary to the second base; n) contacting the templates with the at least a second extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; o) heating the templates at a temperature effective to disassociate the third single stranded oligonucleotide; p) annealing a fourth single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the third single-stranded oligonucleotide plus a third additional 3′ base complementary to the third base; q) contacting the templates with at least a third extending and labeling composition comprising four deoxynucleotide triphosphates, at least one of which comprises a detectable label, under conditions effective to completely extend the non-template strand; r) contacting the templates with at least a first degrading composition under conditions effective to degrade the non-template strands containing a uracil base; and s) detecting the nucleic acid products under conditions effective to determine the position of the selected trinucleotide sequence in the nucleic acid templates. Further methods of the present invention are methods of sequencing a nucleic acid molecule by identifying a selected dinucleotide sequence comprising a first base and a second base, the methods comprising: a) creating a substantially double-stranded nucleic acid template comprising a selected dinucleotide sequence on a template strand and comprising an exonuclease-resistant nucleotide in the non-template strand, wherein the base of the exonuclease-resistant nucleotide is complementary to the first base; b) contacting the template with an amount of an exonuclease effective to degrade the non-template strand until the position of the exonuclease-resistant nucleotide; c) removing the exonuclease from contact with the template; d) contacting the template with at least a first terminating composition comprising a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the second base, under conditions effective to produce a nucleic acid product terminating with a dinucleotide sequence complementary to the first and second base; and e) detecting the nucleic acid product under conditions effective to identify the selected dinucleotide sequence in the template strand of the nucleic acid template. Detection of a selectively-terminated nucleic acid product or products is also generally integral to the use of the invention in methods for mapping a nucleic acid, wherein the methods generally comprise detecting the nucleic acid product or products under conditions effective to determine the position of the nucleic acid relative to the nucleic acid product or products. The mapping methods may comprise: a) creating a population of substantially double-stranded nucleic acid templates from the nucleic acid, the templates comprising at least a first random break on at least one strand or at least a first random break on only one stand; b) contacting the population of templates with an effective polymerase and at least a first degradable extension-producing composition comprising three non-degradable extending nucleotides (deoxynucleotides) and one degradable nucleotide, under conditions and for a time effective to produce a population of degradable nucleic acid products comprising the degradable nucleotide; c) removing the degradable extension-producing composition from contact with the templates; d) contacting the population of degradable nucleic acid products with an effective polymerase and at least a first nondegradable extending and terminating composition comprising four non-degradable extending deoxynucleotides, at least one of the non-degradable extending deoxynucleotides comprising a detectable label or an isolation tag, under conditions and for a time effective to produce a population of terminated nucleic acid products comprising a degradable region and a nondegradable region; e) contacting the population of terminated nucleic acid products with an effective amount of a degrading composition to degrade the degradable region, thereby producing nested nucleic acid products; and f) detecting the nested nucleic acid products under conditions effective to determine the position of the nucleic acid relative to the nucleic acid product. As used herein, the term “nested nucleic acid products” means a series of nucleic acid products that are a different distance from the point that the nucleic acid synthesis originates. In certain aspects, the products will be overlapping nucleic acid products, but this is not a requirements for most of the embodiments of the present invention. In preferred embodiments, the degradable nucleotide will be a uracil base-containing nucleotide and the degrading composition will comprise a combined effective amount of a uracil DNA glycosylase enzyme and an endonuclease IV or an endonuclease V enzyme. The present invention still further provides methods of sequencing through a telomeric repeat region into a subtelomeric region, comprising: a) providing a substantially double-stranded nucleic acid that comprises, in contiguous sequence order, a terminal single-stranded telomeric overhang, a double-stranded telomeric repeat region and a double-stranded subtelomeric region; b) contacting the nucleic acid with a composition comprising an oligonucleotide or primer that is substantially complementary to and hybridizes to the single-stranded telomeric overhang, an effective polymerase, four extending nucleotides and at least a first tagged or labeled terminating nucleotide under conditions effective to produce a nucleic acid product extended from the primer into the subtelomeric region; and c) detecting the nucleic acid product under conditions effective to determine the nucleic acid sequence of the telomeric overhang, the telomeric repeat region and at least a portion of the subtelomeric region. The present invention also provides a method for determining the percentage of telomeres in a population that contain 3′ overhangs, comprising: a) contacting a telomere-containing nucleic acid sample suspected of having telomeres containing a first, 3′ overhang-containing strand and a second, non-overhang strand, with a composition comprising an oligonucleotide or primer that is substantially complementary to and hybridizes to the single-stranded telomeric overhang, an effective polymerase and four extending nucleotides under conditions effective to produce a nucleic acid product extended from the primer and a trimmed second, non-overhang strand, wherein a telomere that does not have a 3′ overhang will comprise a non-trimmed second, non-overhang strand; and b) detecting the nucleic acid product under conditions effective to determine the amounts of the nucleic acid product, the trimmed second, non-overhang strand, the first, 3′ overhang-containing strand and the non-trimmed second, non-overhang strand. In particular aspects, the amounts of the nucleic acid product, the trimmed second, non-overhang strand, the first, 3′ overhang-containing strand and the non-trimmed second, non-overhang strand are determined by hybridization with labeled G-rich and C-rich telomeric sequences or segments. The term “oligonucleotide”, as used herein, defines a molecule comprised of two or more deoxyribonucleotides or ribonucleotides, usually more than three (3), and typically more than ten (10) and up to one hundred (100) or more. Preferably, “oligos” comprise between about fifteen or twenty and about thirty deoxyribonucleotides or ribonucleotides. Oligonucleotides may be generated in any effective manner, including chemical synthesis, DNA replication, reverse transcription, or a combination thereof. A primer is said to be “substantially” complementary to a strand of specific sequence of a template where it is sufficiently complementary to hybridize to the template sufficient for primer elongation to occur. A primer sequence need not reflect the exact sequence of a template. For example, a non-complementary nucleotide fragment may be attached to the 5′ end of a primer, with the remainder of the primer sequence being substantially complementary to a template. Non-complementary bases or longer sequences can be interspersed into a primer, provided that the primer sequence has sufficient complementarity with the sequence of the template to hybridize and thereby form a template primer complex for synthesis of the extension product of the primer. “Hybridization” methods involve the annealing of a complementary or sufficiently complementary sequence to a target nucleic acid sequence. The ability of two polymers of nucleic acid containing complementary sequences to anneal through base pairing interaction is a well-recognized phenomenon (Marmur and Lane, 1960; Doty et al., 1960). The “complement” of a nucleic acid sequence as used herein refers to an oligonucleotide which, when aligned with the nucleic acid sequence such that the 5′ end of one sequence is paired with the 3′ end of the other, is in “antiparallel association.” Certain bases not commonly found in natural nucleic acids may be included in the nucleic acids of the present invention and include, for example, inosine and 7-deazaguanine. Complementarity need not be perfect; stable duplexes may contain mismatched base pairs or unmatched bases. Those skilled in the art of nucleic acid technology can determine duplex stability empirically considering a number of variables including, for example, the length of the oligonucleotide, base composition and sequence of the oligonucleotide, ionic strength and incidence of mismatched base pairs. Stability of a nucleic acid duplex is measured by the melting temperature, or “Tm.” The Tm of a particular nucleic acid duplex under specified conditions is the temperature at which on average half of the base pairs have disassociated. The equation for calculating the Tm of nucleic acids is well known in the art. As indicated by standard references, an estimate of the Tm value may be calculated by the equation: Tm=81.5° C.+16.6 log M+0.41(% GC)−0.61(% form)−500/L where M is the molarity of monovalent cations, % GC is the percentage of guanosine and cytosine nucleotides in the DNA, % form is the percentage of formamide in the hybridization solution, and L=length of the hybrid in base pairs (Berger and Kimmel, 1987). More sophisticated computations are also known in the art that take structural as well as sequence characteristics into account for the calculation of Tm. The invention yet further provides methods of determining the length of a single-stranded overhang of a telomere, comprising contacting a telomere comprising a single-stranded overhang with an excess of a primer that hybridizes to the single-stranded overhang under conditions effective to allow hybridization of substantially complementary nucleic acids, and quantitating the primers thus hybridized to the single-stranded overhang. These methods may further comprise contacting the primers hybridized to the single-stranded overhang with a ligation composition in an amount and for a time effective to ligate the primers, wherein the length of the ligated primers is quantitated. BRIEF DESCRIPTION OF THE DRAWINGS The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein. FIG. 1. A unique plasmid vector utilized in one embodiment of the method of double-stranded sequencing of the present invention. Shown is an insert to be sequenced, represented by the double-headed arrow, flanked by two endonuclease recognition and cleavage sites, in this case two I-SceI sites. An fd gene II nick site is used to create a nick by treatment with fd endonuclease. The nick is used to initiate the strand replacement sequencing reaction. FIG. 2. Schematically shows a strand-specific nick at the fd gene II site of a double-stranded template flanked by I-SceI sites to initiate the strand replacement reaction of the present invention. The newly synthesized strand is shown as a bold line. FIG. 3. Schematically shows the products of the stand replacement method when carried out in the presence of termination nucleotides (closed circles). Also shown is the optional step of restriction digestion at restriction endonuclease sites X and Y. FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 4E, FIG. 4F, FIG. 4G, FIG. 4H, and FIG. 4I. Schematically shows one embodiment of the strand replacement method of the present invention used to map the positions of bases along DNA of multiple restriction fragments. FIG. 4A shows the DNA segment to be sequenced (double headed arrow) and the f1 origin of replication site used to produce the single-stranded nick. FIG. 4B shows the DNA after the nick has been introduced by f1 endonuclease. FIG. 4C shows the initiation of the strand replacement reaction (bold line). FIG. 4D shows the extension of the strand replacement reaction (bold line). FIG. 4E shows the termination of the strand replacement reaction (closed circle) on one DNA molecule. FIG. 4F shows a population of DNA molecules with strand replacement reactions (bold line), terminated at different locations (closed circles). FIG. 4G shows the population of DNA molecules with strand replacement reactions (bold line), terminated at different locations (closed circles) from FIG. 4F, with the location of restriction endonuclease sites X and Y indicated. Cleavage with restriction enzyme X produces the fragments 1, 2 and 3, while cleavage with the restriction enzyme Y produces the fragments 4 and 5. FIG. 4H shows the products of the restriction endonuclease digests X and Y on the DNA. FIG. 4I shows the strand replacement reactions (bold lines) terminated at different positions (closed circles) on fragment 4 produced from a restriction digest of the population of molecules shown in FIG. 4G. The labeled strand replacement strands are denatured, and run on a sequencing gel to determine the sequence. FIG. 5. Schematically shows one embodiment of the strand replacement method of the present invention whereby sequencing can be performed directly on restriction fragments, without size fractionation. The top panel shows a plasmid having a single BamHI restriction endonuclease site. Strand replacement reaction is initiated at the f1 origin of replication (f1 ori), and proceeds through the DNA to be sequenced (bold line). The products of the strand replacement reaction are cut with BamHI, which produces a population of fragments with the strand replacement reactions terminated at different positions (closed circles; bottom panel). FIG. 6. Schematically shows two embodiments of the ligation-mediated method of the present invention for initiation of strand replacement DNA sequencing. A DNA segment containing a EcoRI restriction endonuclease site is cut with EcoRI (1), which produces a fragment with a 5′ extension. Shown are two ways this fragment can be used to produce an initiation site for a strand replacement reaction. The fragment can be treated with phosphatase to remove the terminal 5′ phosphate (2), and then annealed to an adaptor (3) having an EcoRI 5′ overhang. The annealed product has a single-stranded nick, corresponding to the missing phosphate group removed by the phosphatase reaction. Alternatively, the original fragment can be annealed with an adaptor having an extra base in the 5′ overhang (4), producing a product having a one-base nick. Both nicked products can then be used in a strand replacement reaction. FIG. 7A, FIG. 7B, FIG. 7C, FIG. 7D and FIG. 7E. Schematically shows different embodiment of the strand replacement method of the present invention for sequencing PCR™ products. FIG. 7A. In this method, one of the PCR™ primers has an f1 endonuclease recognition site incorporated into the sequence, while the second PCR™ primer does not Treatment of the PCR™ product with f1 endonuclease produces a nick at the f1 recognition site. The nick can be used to initiate a double-stranded sequencing reaction. FIG. 7B. In this embodiment, one of the strands of the PCR™ product has a phosphorothioate linkage incorporated into an EcoRV restriction endonuclease site. Treatment with EcoRV produces a nick in the strand opposite the phosphorothioate linkage, that can be utilized to prime a double-stranded sequencing reaction. FIG. 7C. In yet another embodiment, the PCR™ products can be subjected to treatments to degrade a few nucleotides from the 5′ termini, for example by use of T7 gene 6 exonuclease. Subsequent hybridization of an oligonucleotide primer under non-denaturing conditions to the 3′ tail of the PCR™ product will produce the priming site necessary for initiation of the double-stranded sequencing reaction. FIG. 7D. In this aspect of the invention, dUTP present in one of the PCR™ primers is degraded, and as shown in FIG. 7C hybridization of an oligonucleotide primer under non-denaturing conditions to the 3′ tail of the PCR™ product produces a priming site that can be used to initiate a strand replacement reaction. FIG. 7E. In this embodiment, only one uracil base is incorporated into the PCR™ product through one of the PCR™ primers. The uracil base can be removed by uracil DNA glycosylase, and a nick created by subsequent treatment with heat, base, or an enzyme such as endonuclease IV or endonuclease V. The nick can be used to initiate a double-stranded sequencing reaction. FIG. 8. Schematically shows one embodiment of the strand replacement method of the present invention for mapping the distance of genetic sites from the strand replacement initiation site. A template DNA molecule having detectable features to be mapped and a strand replacement initiation site is shown in the top panel. The bottom panel shows the products of strand replacement reactions with dUTP incorporation times of 0, 10, 20, 30 and 40 minutes, followed by a 1 minute strand replacement reaction incorporating dTTP. The thymidine-containing DNA synthesized by the strand replacement reaction is shown as a cross-hatched box, and the uridine-containing DNA synthesized by the strand replacement reaction is shown as a hatched line. FIG. 9. Schematically shows one embodiment of the strand replacement method of the present invention for producing groups of short DNA molecules at different distances from an initiation site. The top panel shows a DNA molecule having a single fd nick site. The bottom panel shows the products of a strand replacement reaction incorporating dUTP for different amounts of time, followed by incorporation of labeled dTTP for a short, fixed time. The DNA containing dUTP, which can be degraded, is shown as a cross-hatched box, and the DNA containing labeled dTTP, that is stable to degradation and can be used, for example, in array hybridization, is shown as a solid box. FIG. 10A, FIG. 10B, FIG. 10C, FIG. 10D and FIG. 10E. Schematically shows the introduction of single-stranded regions in a model telomere double-stranded construct, and PENT reactions using the TelC primers. FIG. 10A shows the starting Sty11 plasmid construct, having an 800 bp telomere tract (vertical lines) flanked by EcoRI restriction sites, after restriction digest with ClaI. FIG. 10B shows the product of the reaction of the starting construct with Bal 31 nuclease and T7 gene 6 exonuclease, having a G-overhang in the telomere tract. FIG. 10C shows the hybridization of the TelC primers to the G-overhang region of the telomere tract FIG. 10D shows the product of the extension reaction with Taq DNA polymerase and dATP, dCTP and dTTP. CS is the newly-synthesized extension products, Ct is the trimmed original C-rich strands, and Co is the original G-rich strands and untrimmed C-rich strands. FIG. 10E shows the product of the extension reaction with Taq DNA polymerase and all four deoxynucleotides dATP, dCTP, dTTP and dGTP. CS is the newly-synthesized extension products, Ct is the trimmed original C-rich strands, and Co is the original G-rich strands and untrimmed C-rich strands. FIG. 11. A plot used to calculate the estimated telomere overhang length. The vertical axis shows the magnitude of the nondenaturing hybridization signal for constructs with 100 bp, 170 bp and 220 bp G tails (hybridization signal, a.u.), and the horizontal axis shows the length of the overhang (bp). FIG. 12. Schematically shows the functional parts of telomeres, and determination of telomere length by using the PENT reaction. The top panel shows a terminal restriction fragment of a chromosome containing a telomere, with A representing the region of the chromosome that does not contain restriction sites and does not contain repetitive DNA; B representing the region that contains some repetitive DNA and that might include variants of the telomeric sequence (this region is not thought to be a functional part of the telomere); C representing the functional telomeric sequence, with the repetitive sequence (TTAGGG)n; and D representing the single-stranded G-tail (TTAGGG)n. The subtelomeric region is classified as regions A and B. The site of the first guanine in the C-rich strand is indicated. The bottom panel shows the DNA synthesized by the PENT reaction using only dATP, dTTP and dCTP, carried out for 10, 20, 30 and 40 minutes. FIG. 13. Schematically sets forth one embodiment of the strand replacement method for measuring different distances from the termini of chromosomes. The top panel is reproduced from FIG. 12, showing the different regions of the terminal restriction fragment of a chromosome containing a telomere. The bottom panel shows the products of the PENT reactions with dUTP incorporation times of 0, 10, 20, 30 and 40 minutes, followed by a 1 minute PENT reaction incorporating dTTP. The thymidine-containing DNA synthesized by the PENT reaction is shown as a cross-hatched box, and the uridine-containing DNA synthesized by the PENT reaction is shown as a hatched line. FIG. 14A and FIG. 14B. Shows the sequencing gel results following strand replacement performed according to the present invention. FIG. 14A. Sequencing reactions run in buffer A. FIG. 14B. Sequencing reactions run in buffer B. FIG. 15. Schematically sets forth RBI sequencing with detectable primer and biotinylated ddTTP. The top panel shows a PCR™-amplified DNA with a detection tag at the 5′ end of primer X (open circle). The numbers show the 12 unknown bases. The next panel shows the population of products of random degradation (nicks shown on upper strand only), with each of the twelve unknown bases being nicked. The next panel represents the products of the random degradation after exposing the 3′ hydroxyl group at the damage site. The next panel shows the incorporation of biotinylated ddTTP at positions opposite adenine in the template stand. The next panel shows the immobilization of the biotinylated strands, and removal of the non-biotinylated strands. The bottom panel is a schematic representation of the released biotinylated strands separated by electrophoresis, and detection of the tagged primer. The dark bars represent the position of thymine. FIG. 16. Schematic depiction of size separation of separate RBI reactions terminated with tagged ddNTPs. The top panel schematically shows the results from the reactions performed as described in FIG. 15 using biotinylated ddTTP, biotinylated ddATP, biotinylated ddCTP and biotinylated ddGTP. The bottom panel shows a schematic representation of the summation of the results from the top panel, showing the complete base sequence. FIG. 17. Schematically sets forth RBI with detectable primer and biotinylated dTTP. The top panel shows a PCR™-amplified DNA with a detection tag at the 5′ end of primer X (open circle). The numbers show the 12 unknown bases. The next panel shows the population of products of random degradation (nicks shown on upper strand only), with each of the twelve unknown bases being nicked. The next panel represents the products of the random degradation after exposing the 3′ hydroxyl group at the damage site. The next panel shows the incorporation of biotinylated dTTP at positions opposite adenine in the template strand. The next panel shows the immobilization of the biotinylated strands, and removal of the non-biotinylated strands. The bottom panel is a schematic representation of the released biotinylated strands separated by electrophoresis, and detection of the tagged primer. The dark bars represent the position of terminal thymine. FIG. 18. Schematic depiction of size separation of separate RBI reactions terminated with tagged dNTP. The top panel schematically shows the results from the reactions performed as described in FIG. 17 using biotinylated dTTP, biotinylated dATP, biotinylated dCTP and biotinylated dGTP. The bottom panel shows a schematic representation of the summation of the results from the top panel showing the complete base sequence. The positions of the bases in parentheses are inferred. FIG. 19. Schematically sets forth RBI with detectable ddNTP and biotinylated primer. The top panel shows a PCR™-amplified DNA immobilized at the 5′ end of primer X (open circle). The numbers show the 12 unknown bases. The next panel shows the population of products of random degradation (nicks shown on upper strand only), with each of the twelve unknown bases being nicked. The next panel represents the products of the random degradation after exposing the 3′ hydroxyl group at the damage site. The next panel shows the incorporation of tagged (labeled) ddTTP at positions opposite adenine in the template strand. The next panel shows the denaturation and removal of the non-immobilized strands. The bottom panel is a schematic representation of the mobilized, originally retained strands separated by electrophoresis, and detection of the tagged bases. The dark bars represent the position of thymine. FIG. 20. Schematic depiction of size separation of separate RBI reactions terminated with detectable tagged ddNTP. The top panel schematically shows the results from the reactions performed as described in FIG. 19 using tagged ddTTP, tagged ddATP, tagged ddCTP and tagged ddGTP. The bottom panel shows a schematic representation of the summation of the results from the top panel, showing the complete base sequence. FIG. 21. Schematically sets forth double-base sequencing by RBI (example shown is a “T-walk” followed by “A-walk”). The PCR-amplification, immobilization, 3′ hydroxyl group exposure at random sites is conducted as detailed in FIG. 19. The top panel shows the population of products of random degradation (nicks shown on upper strand only), with each of the twelve unknown bases being nicked. The next panel shows blocking of the positions opposite T, G and C with ddATP, ddCTP and ddGTP (shown in bold letters), followed by removal of the ddATP, ddCTP and ddGTP, and addition of dTTP, which has a 3′ hydroxyl group that serves as an initiation site for further nucleotide addition. The next panel shows blocking of positions opposite A, G and C with ddTTP, ddCTP and ddGTP (shown in bold letters), followed by the removal of the ddTTP, ddCTP and ddGTP, and addition of tagged (labeled) ddATP. The next panel shows denaturation and removal of the non-immobilized strands. The bottom panel is a schematic representation of the mobilized, originally retained strands separated by electrophoresis, and detection of the tagged bases. The dark bars represent the position of thymine followed by adenine. FIG. 22. Schematic depiction of size separation results from twelve 2-base walks put together in complete sequence. The top panel schematically shows the results from the reactions performed as described in FIG. 21 using a T/A walk, a T/C walk, a T/G walk, a A/T walk, a A/C walk, a A/G walk, a C/T walk, a C/A walk, a C/G walk, a G/T walk, a G/A walk, and a G/C walk. The bottom panel shows a schematic representation of the summation of the results from the top panel, showing the complete base sequence. The inferred bases are shown in parentheses. FIG. 23. Schematically sets forth an example of a three-base walk finding the position of the succession TaAbT. The PCR-amplification, immobilization, 3′ hydroxyl group exposure at random sites is conducted as detailed in FIG. 19. The top panel shows the population of products of random degradation (nicks shown on upper strand only), with each of the twelve unknown bases being nicked. The next panel shows blocking of the positions opposite T, G and C with ddATP, ddCTP and ddGTP (shown in bold letters), followed by removal of the ddATP, ddCTP and ddGTP, and addition of dTTP, which has a 3′ hydroxyl group that serves as an initiation site for further nucleotide addition. The next panel shows blocking of positions opposite A, G and C with ddTTP, ddCTP and ddGTP (shown in bold letters), followed by the removal of the ddTTP, ddCTP and ddGTP, and addition of dATP, which has a 3′ hydroxyl group that serves as an initiation site for further nucleotide addition. The next panel shows blocking of the positions opposite T, G and C with ddATP, ddCTP and ddGTP (shown in bold letters), followed by removal of the ddATP, ddCTP and ddGTP, and addition of tagged (labeled) ddTTP. The bottom panel is a schematic representation of the denaturation and removal of the non-immobilized strands, the mobilization of the originally retained strands and separation by electrophoresis, and detection of the tagged terminal thymidine. The dark bar represents the position of thymine followed by adenine, followed by thymine. FIG. 24. The results of single-base extension experiment analyzed by polyacrylamide gel electrophoresis. Lane 1 represents primer A (21 bases), primer G (23 bases), primer T (25 bases), and primer C (28 bases) before extension. Lanes 2-5 represent products of single-base extension reactions in the presence of 1 μM α-S-dCTP, 10 μM α-S-dGTP, 10 μM α-S-dTTP, and 10 μM α-S-dATP, respectively. Arrows indicate the positions of elongated products. FIG. 25. The results of the dd(-N)-blocking reactions using different concentrations of “dd(-A) mix” (lanes 1-4), “dd(-T) mix” (lanes 5-8), “dd(-G) mix” (lanes 9-12), and “dd(-C) mix” (lanes 13-16) analyzed by polyacrylamide gel electrophoresis. Lanes 1, 5, 9, and 13 correspond to 1/10,000 of stock concentration; lanes 2, 6, 10, and 14 correspond to 1/1000 of stock concentration; lanes 3, 7, 11, and 15 correspond to 1/100 of stock concentration; and lanes 4, 8, 12, and 16 correspond to 1/10 of stock concentration of “dd(-N) mixes.” FIG. 26. Extension of those primers that should still have 3′ OH groups after the blocking reactions. Lanes 1, 3, 5, and 7 contain the oligonucleotide mixture after the blocking reactions with “dd(-A)”, “dd(-T)”, “dd(-G)”, and “dd(-C)” mixes, respectively. Lanes 2, 4, 6, and 8 contain the products of polymerase extension of the DNA in lanes 1, 3, 5, and 7, respectively. Lane 9 contains unextended primers. FIG. 27. Patterns of DNA degradation caused by Fe/EDTA and DNase I treatment are nearly random. Lanes 1, 2, 3, 4, and 5 correspond to 0, 15 sec, 30 sec, 1 min, 2 min of incubation of immobilized DNA with Fe/EDTA. Lanes 6, 7, 8, 9, and 10 correspond to 0, 1 min, 2 min, 5 min, 10 min of incubation of immobilized DNA with DNase I. FIG. 28A and FIG. 28B. pUC19 DNA samples after Fe/EDTA treatment, conditioning and DNA polymerase labeling run on 1% agarose gel. FIG. 28A. Ethidium bromide staining of the gel. FIG. 28B. Autoradiogram of the DNA. Lanes 1 and 7: non-conditioned Fe/EDTA treated DNA; lanes 2 and 8: DNA conditioned with T4 DNA polymerase only; lanes 3 and 9: DNA conditioned with combined action of T4 DNA polymerase and 0.1 U exo III; lanes 4 and 10: DNA conditioned with combined action of T4 DNA polymerase and 0.3 U exo III; lanes 5 and 11: DNA conditioned with combined action of T4 DNA polymerase and 1 U exo III; lanes 6 and 12: DNA conditioned with combined action of T4 DNA polymerase and 3 U exo III. FIG. 29. Results of specific incorporation of 32P α-dATP into Fe/EDTA randomly nicked DNA. Lanes 1-3 correspond to labeling reactions performed at 30 nM , 100 nM, and 300 nM of α-dATP, respectively. Lane 4 corresponds to non-degraded control DNA incubated with 100 nM α-dATP. FIG. 30A and FIG. 30B. FIG. 30A. Structure of an exemplary 5′ phosphorylated, 3′-blocked oligonucleotide adaptor as described in Example 10, used to create a randomly positioned nick or template sequence (top strand, W). Filled circle indicates 5′ phosphate group, filled squares indicate blocked 3′-ends (dideoxynucleotide or NH2 group). FIG. 30B. General structure of primers C-X, C-XY and C-XYZ as described in Example 10 for use in three different selection protocols. FIG. 31. Schematic representation of multi-base sequence analysis of randomly broken DNA as described in Example 10. FIG. 32. Schematic representation of the sequential blocking-extension procedures as described in Example 10 for selection of DNA fragments that have 5′-ATG-3′ base combination at their 5′ adapted termini from a pool of randomly terminated DNA fragments. Filled squares indicate blocked 3′-ends; arrows indicate non-blocked 3′-OH ends. FIG. 33A and FIG. 33B. One-step selection procedures as described in Example 10. FIG. 33A. Selection procedure utilizing the primer-selectors C-X, C-XY and C-XYZ, as shown in FIG. 30B, and polymerization reaction on the single-stranded template. FIG. 33B. Selection procedure utilizing strand-displacement hybridization reaction of the primer-selectors C-X, C-XY and C-XYZ facilitated by the removal of the displaced 5′-overhang DNA by exonuclease digestion, followed by polymerization reaction on the double-stranded template. DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS The limited length of DNA sequence that can be determined in one sequencing reaction is a fundamental problem in sequencing. Two types of solutions have been proposed and experimentally tested. The first type of solutions are all attempts to find better techniques to size-separate DNA molecules, including modifications to the composition of the electrophoretic gel matrix, modifications to the electrophoretic devices and electric field characteristics, using liquid chromatography, and using mass spectrometry to determine fragment lengths. After years of refinement of electrophoretic methods, it is still not possible to separate molecules longer than about 1000-1400 bases with single-base resolution. This is because as the molecular weight of the DNA increases the gel bands become closer and closer together, until the bands from molecules of length n overlap those of length n+1, making it impossible to determine which base is at position n and which base is at position n+1. Additionally, due to technical limitations of the resolution and sensitivity of mass spectrometry, it has not been possible to separate molecules longer than about 50 to 100 bases with sufficient signal to noise ratio to distinguish molecules that differ in length by a single base (WO 96/32504). The second type of solutions are attempts to avoid electrophoresis altogether. This class includes sequencing by microscopy, hybridization, step-by-step degradation of labeled bases from one end, and step-by-step addition of bases to one end. The microscopic methods depend upon determination (by direct imaging) of the position of a specific base along the DNA. In that respect they directly determine the distance between one end of the DNA molecule and the position of a specific base, and therefore share a common principle with all the size-separation techniques including gel electrophoresis. Electron microscopy, scanning tunneling microscopy, atomic force microscopy, and other microscopies have inherent resolution better than 0.2 nm, which is less than the spacing between DNA bases in double or single stranded DNA. Therefore, in principle, if individual base types could by identified by microscopy the entire sequence of a very long piece of DNA could be determined. Dispite many attempts to sequence by microscopy, technical problems including physical damage during imaging and difficulties in labeling and detecting specific bases have prevented this technique from being used to determine the position of specific bases, even in very short pieces of DNA. Sequencing by hybridization is based on determining the presence of a specific short sequence (4-10 bases) without direct localization of the sequence on a longer piece of DNA (Drmanac et al., 1989). Computer analysis of the short sequences present can be used to reconstruct the sequence of a larger fragment of DNA. To date, this method is limited to DNA molecules of less than about 50 bases in length. Methods of sequentially degrading bases from one end of a long DNA molecule using a exonuclease while simultaneously identifying the released bases have also been proposed (Jones et al., 1997). In principle this could be done using a single molecule or with a collection of identical molecules. The single-molecule methods have not proven practical due to difficulty in degrading the DNA rapidly enough and labeling and detecting the released labeled bases. The multi-molecule methods are not practical because all molecules in the set cannot be degraded synchronously. Step-by-step incorporation of detectable bases from one end of a collection of identical molecules has also been proposed (WO 90/13666; WO 93/21340; U.S. Pat. No. 5,302,509; U.S. Pat. No. 5,750,341). In one version of this technique the specific base is identified by reduction in the amount of labeled nucleotide triphosphate precursors in the solution. In another version, the pyrphosphate molecules released during each polymerization step are detected in solution (Hyman, 1988; Ronghi et al., 1996, 1998). In a third version, the base is identified by incorporation and detection of a labeled nucleotide. All of these methods for step-by-step addition of nucleotides to one end of a collection of molecules suffer from the same shortcomings as encountered by the step-by-step degradation methods, specifically the difficulty to maintain registration of the positions of incorporation of nucleotides into different molecules. The present invention overcomes these and other limitations present in the art Certain aspects of the present invention increase the length of DNA sequence that can be determined from one biochemical reaction by increasing ability of any size-separation technique (e.g., mass spectroscopy, gel electrophoresis, gel chromatography) to determine the positions of bases. This principle, multibase sequencing, and all the instant methods described herein that implement the principle, reduces the number of fragments that need to be resolved in each gel lane or capillary and thereby increases the chance that the bands from molecules of similar size can be distinguished. Multibase sequencing creates or selects a nested set of DNA double-stranded or single-stranded DNA molecules that have their proximal termini located at a specific position in the DNA sequence and their distal termini located at the positions of a specific dinucleotide (e.g., AT, TT, GT, etc.), trinucleotide (e.g., ATA, GGT, CTG, etc.), or n-base string (e.g., ATGCTGG). The DNA molecules created or selected with a specific base string at the distal ends are size-separated by electrophoresis, mass spectrometry, or other techniques to form a multi-base ladder similar to the single-base ladders formed in the Sanger or Maxim-Gilbert techniques. For example, all those molecules terminated with the dinucleotide AT can be separated by electrophoresis to form a ladder of bands that specify the positions of the dinucleotide relative to the unique site at the proximal ends of the molecules. The average spacing between the bands will be about 16 bases (e.g., the average spacing between occurances of the dinucleotide AT). Because the average spacing between gel bands in the dinucleotide ladder is four times larger than the average spacing between bands in a conventional single-base ladder, adjacent sequencing bands will overlap less frequently and therefore be resolved more frequently. In addition, even when bands in different dinucleotide ladders are of such similar size that they migrate the same distance, the information in the dinucleotide types can be used to resolve the sequence. For example, if a band of the “AT” ladder overlaps a band on the TG ladder, the sequence at that position can be determined to be ATG. An additional advantage of this approach is that the position of the central thymine base is determined from the information in two independent sequencing ladders. This “oversampling” of the information decreases the frequency of misidentification of the base at a specific position. The information in all 16 possible dinucleotide ladders can be combined to determine the sequence even when three or more bands migrate identically. For example, if the dinucleotide ladders with molecules terminating at AT, GA, TG, NA, and AN overlap (where N is some other base), the sequence at a specific positions can be deetermined to be ATGA. The intensity of the dinucleotide bands can be used to determine the number of occurances of a specific dinucleotide within a region, even if the individual dinucleotide bands are not resolved. For example, if the dinucleotides TA, AT, and AA have indistinguishable electrophoretic mobility, and the AA band is twice as strong as the other bands, it can be determined that the sequence at that position is TAAAT. When the resolution of the size-separation technique is insufficient to unambigously assign a specific sequence at a position, the information available will determine a small number of sequences allowed that will be a subset of all the sequences possible. The determination of the unique sequence or limited set of sequences that are consistent with a specific pattern of multibase ladders can be determined as described above; however, the inventors also contemplate that computer software, such as that used for sequence analysis, comparing sequences in different genes and different organisms, determining the overlapping sequences of different fragments in shotgun sequencing, and in determining DNA sequences using the sequencing by hybridization approach, can be used or modified to assist in sequence determination using multibase sequencing. The consequence of being able to determine the base sequence from multibase sequencing ladders with closely-spaced or completely overlapping bands is the ability to determine the base sequence in molecules longer than possible using single-base sequencing methods. As shown above, even if the size-separation technique is limited to distinguishing DNA length n from n+2, a dinucleotide ladder will be sufficient to determine the bases at position n, n+1, and n+2. By relaxing the resolution requirements by a factor of two (or more) the length of sequences that can be “read” from one size separation will be increased by approximately a factor of two. The ability to read longer sequences of DNA will improve sequencing using all technical methods of size-separation, including gel electrophoresis, liquid chromatography, and mass spectrometry. In a most general sense, the present invention provides a number of methods that can be used in a variety of embodiments, including, but not limited to, creation of a nucleic acid terminated at one or more selected bases, sequence analysis of nucleic acids, mapping of sequence motifs within a nucleic acid as well as positional mapping of nucleic acid clones, and analysis of telomeric regions. I. Creation of Nucleic Acid Product Terminated at a Selected Base A. Methods for Creating an Initiation Site In certain embodiments of the present invention, an initiation site for nucleic acid synthesis must first be created in the substantially double stranded nucleic acid. The initiation site (as distinct from an oligonucleotide primer) can be introduced by any method that results in a free 3′ hydroxyl group on one side of a nick or gap in otherwise substantially double-stranded nucleic acid. Presented herein are a variety of methods for creation of an initiation site, including creation of a specific break or nick in one or both strands of the double-stranded nucleic acid, creation of a random break or nick in one or both strands of the double-stranded nucleic acid, creation of a single-stranded gap on one or both strands of the substantially double-stranded nucleic acid, and creation of a double-stranded break. In certain of the methods of creating an initiation site described herein below, a nick or break is created that does not result in the formation of a 3′ hydroxyl group. As the polymerase synthesis reactions described herein require a 3′ hydroxyl group to initiate synthesis, also provided are methods of conditioning the break or nick, in order to create an initiation site that possesses a 3′ hydroxyl group. 1. Creation of a Specific Break or Nick In certain aspects of the present invention, it is desired to create an initiation site at one or more specific location(s) within the nucleic acid. Methods for creation of one or more specific breaks or nicks include, but are not limited to: enzymatic methods utilizing one or a combination of different enzymes; chemical cleavage methods; and methods involving the ligation of a specific nucleic acid adaptor. a. Enzymatic Methods There are a number of enzymes that have the ability to introduce a single- or double-stranded nicks or breaks into a nucleic acid at one or more specific positions. Examples of enzymatic methods for creating an initiation site include, but are not limited to, digestion of a nucleic acid by a restriction enzyme under conditions that only one strand of the double-stranded DNA template is hydrolyzed, and nicking by f1 gene product II or homologous enzymes from other filamentous bacteriophage. A number of restriction enzymes have been described that produce a single-stranded nick in one strand of a double-stranded nucleic acid when the digest is carried out in the presence of ethidium bromide (Kovacs et al., 1984). After the restriction endonuclease reaction produces a nick in one strand, no further reaction occurs. Therefore, most of the double-stranded nucleic acid molecules will have a single nick on one strand, with some molecules having a nick on the top strand, and some molecules having a nick on the bottom strand. It is also known that certain restriction endonucleases produce a single-stranded nick in the normal strand of a hemiphosphorothiolated (having phosphorothioate linkages on only one strand) double-stranded nucleic acid molecule (Olsen et al., 1990). Depending on which strand contains the phosphorothioate linkages, the nick will be produced on the top strand or the bottom strand. A preferred method of producing a specific nick in a double-stranded nucleic acid is by using the f1 bacteriophage gene product II (f1 endonuclease) or homologous enzymes from other filamentous bacteriophage such as the fd bacteriophage (Meyer and Geider, 1979). Certain single-stranded bacteriophages form a double-stranded “replicative form” (RF) molecule inside the host cell in order to replicate the bacteriophage genome. The RF is nicked at a specific site (the “origin of replication”) on the strand corresponding to the bacteriophage genome, leading to replication of the bacteriophage genome by a strand displacement reaction, also known as rolling circle replication. Thus, a double stranded nucleic acid containing an origin of replication from a filamentous bacteriophage such as f1 or fd, when contacted with the appropriate f1 or fd endonuclease, would be specifically nicked at the origin of replication. Additionally, uracil DNA glycosylase (dU glycosylase) removes uracil residues from nucleic acids, leaving an abasic site. This abasic site can be converted to a nick by heating the nucleic acid, treatment with base, or in combination with an enzyme such as, but not limited to, endonuclease IV or endonuclease V. Thus, by incorporating uracil into one or more specific locations in a double-stranded nucleic acid, for example by synthesizing an oligonucleotide primer with a uracil residue incorporated near the 3′ end of the primer, and using the uracil-containing primer to amplify a double-stranded nucleic acid product, a specific nick can be created in the double-stranded nucleic acid product using these techniques. b. Chemical Methods Certain chemical methods can also be used to produce a specific nick or a break in a double-stranded nucleic acid molecule. For example, chemical nicking of a double-stranded molecule directed by triple-helix formation (Grant and Dervan, 1996). C. Adaptor-Based Methods Ligation can also be used to create an initiation site. This very powerful and general method to introduce an initiation site for strand replacement synthesis employs a panel of special double-stranded oligonucleotide adapters designed specifically to be ligated to the termini produced by restriction enzymes. Each of these adapters is designed such that the 3′ end of the restriction fragment to be sequenced can be covalently joined (ligated) to the adaptor, but the 5′ end cannot. Thus the 3′ end of the adaptor remains as a free 3′ OH at a 1 nucleotide gap in the DNA, which can serve as an initiation site for the strand-replacement sequencing of the restriction fragment. Because the number of different 3′ and 5′ overhanging sequences that can be produced by all restriction enzymes is finite, and the design of each adaptor will follow the same strategy, above, the design of every one of the possible adapters can be foreseen, even for restriction enzymes that have not yet been identified. To facilitate sequencing, a set of such adapters for strand replacement initiation can be synthesized with labels (radioactive, fluorescent, or chemical) and incorporated into the dideoxyribonucleotide-terminated strands to facilitate the detection of the bands on sequencing gels. More specifically, adapters with 5′ and 3′ extensions can be used in combination with restriction enzymes generating 2-base, 3-base and 4-base (or more) overhangs. The sense strand (the upper strand shown in Table 1 below) of the adaptor has a 5′ phosphate group that can be efficiently ligated to the restriction fragment to be sequenced. The anti-sense strand (bottom, underlined) is not phosphorylated at the 5′ end and is missing one base at the 3′ end, effectively preventing ligation between adapters. This gap does not interfere with the covalent joining of the sense strand to the restriction fragment, and leaves a free 3′ OH site in the anti-sense strand for initiation of strand replacement synthesis. TABLE 1 Adapters for Initiation of Strand Replacement DNA Synthesis (a) 2-base 5′ restrict- 5′------ ion extensions: 3′------ab Adapters with 3- abcd---------3′ base 5′ extensions: d---------5′ Litigation product 5′------abcd------------3′ formed: 3′------ab d------------5′ (b) 3-base 5′ restrict- 5′------ ion extensions: 3′------abc Adapters with 4- abcde-------3′ base 5′ extensions: e-------5′ (c) 4-base 5′ restrict- 5′------ ion extensions: 3′------abcd Adapters with 5- abcdef-----3′ base 5′ extensions: f------5′ (d) 2-base 3′ restrict- 5′------ab ion extensions: 3′------ Adapters with 1- c---------3′ base 3′ extensions: bc---------5′ (e) 3-base 3′ restrict- 5′------abc ion extensions: 3′------ Adapters with 2- d--------3′ base 3′ extensions: bcd--------5′ (f) 4-base 3′ restrict- 5′------abcd ion extensions: 3′------ Adapters with 3- e-------3′ base 3′ extensions: bcde-------5′ TABLE 2 Base Extensions And Restriction Enzymes Restriction endonucleases 2-base extensions 5′-CG MaeII, HinPI, NarI, AcyI, HpaII, MspI, TaqI, ClaI, SfuI, AsuII 5′-GC ------ 5′-TA NdeI, MaeI, MseI, AsnI 5′-AT AccI CG-3′ CfoI, HhaI GC-3′ KspI, SacII TA-3′ ------ AT-3′ PvuI 3-base extensions 5′-GNC Sau96, DraII 5′-CNG ------ 5′-ANT HinfI 5′-TNA DdeI, CelII, SauI, Bsu36I GNC-3′ PssI CNG-3′ ------ ANT-3′ ------ TNA-3′ ------ 4-base extensions 5′-AATT EcoRI 5′-GATC MboI, NdeII , Sau3A, BglII, BamHI, BclI, XhoII 5′-CATG NcoI, BspHI 5′-TATA ------ 5′-ATAT ------ 5′-GTAC Asp718, SplI 5′-CTAG SpeI, NheI, AvrII, XbaI 5′-TTAA AflII 5′-AGCT HindIII 5′-GGCC EclXI, XmaIII, NotI, EaeI 5′-CGCG MluI, BssHII 5′-TGCA SnoI 5′-ACGT ------ 5′-GCGC BanI 5′-CCGG XmaI, MroI, Cfr101, SgrAI, AccIII 5′-TCGA SalI, XhoI AATT-3′ ------ GATC-3′ ------ CATG-3′ NlaIII, SphI, NspI TATA-3′ ------ ATAT-3′ ------ GTAC-3′ KpnI CTAG-3′ ------ TTAA-3′ ------ AGCT-3′ SacI GGCC-3′ ApaI CGCG-3′ ------ TGCA-3′ NsiI, PstI ACGT-3′ AatII GCGC-3′ BbeI, HaeII CCGG-3′ ------ TCGA-3′ ------ The adapters can also be designed to have a nick rather than a gap, which will still facilitate initiation of the strand replacement reaction. To do this, the restriction fragments need to be dephosphorylated to prevent ligation of the 5′ end. In this case, blunt end adapters that are compatible with blunt end producing restriction enzymes can be used. 2. Creation of a Random Break or Nick In other aspects of the present invention, it is desired to create an initiation site at one or more random or essentially random location(s) within the nucleic acid. Methods for creation of one or more random breaks or nicks include, but are not limited to: enzymatic methods utilizing one or a combination of different enzymes; chemical cleavage methods; and physical or mechanical methods. a. Enzymatic Methods A preferred method of generating random or essentially random breaks or nicks in a double-stranded nucleic acid is using a nuclease that has no particular sequence requirements for cleavage, for example an endonuclease such as DNAase I. DNAase I is commercially available from a variety of sources, and produces random or essentially random nicks or breaks in double-stranded DNA. Another enzymatic method for generating random or essentially random breaks or nicks is through the use of a restriction enzyme, such as CviJI, that normally has a four base recognition sequence, but under certain buffer and salt conditions has essentially a two base recognition sequence. Other restriction endonucleases, including, but not limited to, ApoI,. AseI, BamHI, BssHII, EcoRI, EcoRV, HindIII, HinfI, KpnI, PstI, PvuII, SalI, ScaI, TaqI and XmnI, are known to possess “star activity,” meaning that under certain conditions, such as high glycerol concentrations, high amounts of restriction enzyme, low ionic strength, high pH, the presence of certain organic solvents, such as DMSO, ethanol, ethylene glycol, dimethylacetamide, dimethylformamide or sulphalane, or substitution of the preferred divalent metal ion (usually Mg2+) with a less preferred divalent metal ion, such as Mn2+, Cu2+, Co2+ or Zn2+, or combinations thereof, recognize and cleave sequences not normally cleaved. Additionally, combinations of restriction enzymes, including those with four base recognition sequences, including, but not limited to, Tsp509I, MaeII, TaiI, AluI, CviJI, NlaIII, MspI, HpaII, BstUI, BfaI, DpnII, MboI, Sau3AI, DpnI, ChaI, HinPI, HhaI, HaeIII, Csp6I, RsaI, TaqI and MseI, and those having “star activity,” can be used in a restriction enzyme “cocktail” to produce essentially random nicks or breaks in a double-stranded nucleic acid. b. Chemical Methods Single-strand breaks can also be produced using hydroxyl radicals generated by a number of methods including treatment with Fenton reaction reagents (a metal ion chelating agent, including, but not limited to EDTA and EGTA, a divalent metal ion, including, but not limited to, Fe2+, Ca2+, Cu2+ and Zn2+, a peroxide and a reducing agent, for example Fe2+/EDTA/H2O2 with sodium ascorbate), or gamma irradiation. The primary products of radical cleavage are randomly-positioned nicks or gaps, usually with 3′ phosphate groups. Therefore the DNA must be processed before the sites can be used to prime DNA synthesis (see Section 3 below). In addition, a number of chemical compounds, particularly dyes, are known to produce hydroxyl radicals upon exposure to certain wavelengths of light. C. Physical/Mechanical Methods There are a number of physical and mechanical methods which are known to produce random single- and double-stranded breaks in nucleic acids. For example, it has long been known that subjecting DNA to hydrodynamic shear can produce random breaks in the DNA molecule. Additionally, sonication can be used, at various power levels, to produce random breaks or nicks in a nucleic acid molecule. Another method that is contemplated for use in the present invention to produce random nicks or breaks is nebulization, which is contacting the nucleic acid molecule with gas or air bubbles. Furthermore, repeated freezing and thawing of nucleic acids can produce random nicks or breaks. 3. Conditioning Nick to Generate 3′ Hydroxyl Group All polymerases studied require 3′ ends with hydroxyl groups in order to incorporate new nucleotides. Therefore breaks in the DNA that do not originally contain 3′ OH groups have to be conditioned to possess 3′ OH groups before strand elongation can be performed. One method to condition the 3′ end is to incubate the DNA in the presence of a 3′ exonuclease such as E. coli exonuclease III, or a DNA polymerase that possesses 3′ to 5′ exonuclease activity. This invention anticipates discovery or engineering of DNA polymerases able to remove nucleotides that do not have 3′ OH groups from the 3′ ends of DNA strands. 4. Extension of Break or Nick to Form Single-Stranded Gap In certain aspects of the invention, a nick or break in the nucleic acid must be extended to form a gap, for example for insertion of bases by a DNA polymerase that lacks strand displacement or 5′ to 3′ exonuclease activity, such as T4 DNA polymerase, or to create a site for primer binding. A preferred enzyme for use in this aspect of the invention is exonuclease III, which can extend a nick or break to form small or large gaps, as desired for the particular application. The exonuclease III reaction is allowed to proceed for a short time to produce small gaps, and longer for larger gaps. 5. Creation of Blunt End In particular aspects of the invention, a double-stranded break is required that is blunt. A number of restriction endonucleases are known that produce blunt ends, including, but not limited to, AluI, CviJI, BstUI, DpnI, HaeIII, RsaI, SspI, Eco47III, StuI, ScaI, PmlI, BsaAI, PvuII, MspAII, Ecl136II, EcoRV, SmaI, NaeI, EheI, Bst1107I, HincII, HpaI, SnaBI, NruI, FspI, MscI and DraI. These enzymes can be used in conjunction with phosphatases, such as bacterial alkaline phosphatase, calf-intestinal alkaline phosphatase or shrimp alkaline phosphatase, to remove the phosphate groups present at the blunt sites. B. Double-Stranded Templates Template DNA can be any double-stranded DNA molecule including, but not limited to native chromosomal or extrachromosomal DNA from any organism, DNA cloned into a bacterial plasmid or virus, plasmids or RF forms of viral DNA, double stranded amplification products, including PCR™ products, and artificially synthesized DNA. Linear and circular DNA of all double-stranded conformations isolated by any technique and of any purity can be used. Although in certain aspects of the invention it is preferred that the template DNA be essentially free from nicks or gaps, DNA samples that do not originally meet this requirement can be treated to remove such defects. Nicks in DNA occur after long-term storage or repeated cycles of freezing and thawing; these defects can be repaired by incubating the DNA with a DNA ligase such as that from bacteriophage T4, or by incubation with a combination of enzymes that repair such defects, as described herein. Gaps can be repaired by incubation with T4 DNA polymerase and ligase. The fact that the template DNA molecules are double-stranded obviates the problems with unusual secondary structures. Moreover, the fact that the product molecules are double-stranded allows long stretches of the product DNA to be subsequently cleaved using restriction enzymes into fragments sufficiently small that they can be subjected to automated sequencing in commercially available sequenators (e.g. those made by ABI, Pharmacia, and other companies). In certain aspects of the invention, the double-stranded nucleic acid template is a restriction fragment from a larger nucleic acid precursor. Restriction enzymes can be used to cut the DNA at sequence specific sites. At least one hundred of these cleavage reagents are commercially available and are able to make double-strand scissions in the DNA in short times. Additionally, other enzymes that cleave DNA in a specific location can be used, for example intron encoded endonucleases such as I-CeuI, I-PpoI, I-TliI and I-SceI, are contemplated for use. In addition to these natural sequence specific endonucleases there are a number of chemical reagents developed to make specific breaks in DNA (Strobel and Dervan, 1992; Grant and Dervan, 1996). 2. Amplification Techniques Nucleic acids used as a template for amplification can be isolated from cells according to standard methodologies (Sambrook et al., 1989). The nucleic acid may be genomic DNA or fractionated or whole cell RNA. Where RNA is used, it may be desired to convert the RNA to a complementary DNA. In one embodiment, the RNA is whole cell RNA and is used directly as the template for amplification. Pairs of primers that selectively hybridize to a specific nucleic acid template are contacted with the isolated nucleic acid under conditions that permit selective hybridization. The term “primer”, as defined herein, is meant to encompass any nucleic acid that is capable of priming the synthesis of a nascent nucleic acid in a template-dependent process. Typically, primers are oligonucleotides from ten to twenty base pairs in length, but longer sequences can be employed. Primers may be provided in double-stranded or single-stranded form, although the single-stranded form is preferred. Once hybridized, the nucleic acid:primer complex is contacted with one or more enzymes that facilitate template-dependent nucleic acid synthesis. Multiple rounds of amplification, also referred to as “cycles,” are conducted until a sufficient amount of amplification product is produced. In certain aspects of the invention, the amplification product is detected. In certain applications, the detection may be performed by visual means. Alternatively, the detection may involve indirect identification of the product via chemiluminescence, radioactive scintigraphy of incorporated radiolabel or fluorescent label or even via a system using electrical or thermal impulse signals (Affymax technology). A number of template dependent processes are available to amplify the marker sequences present in a given template sample. One of the best known amplification methods is the polymerase chain reaction (referred to as PCR™) which is described in detail in U.S. Pat. Nos. 4,683,195, 4,683,202 and 4,800,159, and each incorporated herein by reference in entirety. Briefly, in PCR™, two primer sequences are prepared that are complementary to regions on opposite complementary strands of the marker sequence. An excess of deoxynucleoside triphosphates are added to a reaction mixture along with a DNA polymerase, e.g., Taq polymerase. If the marker sequence is present in a sample, the primers will bind to the marker and the polymerase will cause the primers to be extended along the marker sequence by adding on nucleotides. By raising and lowering the temperature of the reaction mixture, the extended primers will dissociate from the marker to form reaction products, excess primers will bind to the marker and to the reaction products and the process is repeated. A reverse transcriptase PCR amplification procedure may be performed in order to quantify the amount of mRNA amplified. Methods of reverse transcribing RNA into cDNA are well known and described in Sambrook et al., 1989. Alternative methods for reverse trascription utilize thermostable, RNA-dependent DNA polymerases. These methods are described in WO 90/07641, filed Dec. 21, 1990, incorporated herein by reference. Polymerase chain reaction methodologies are well known in the art. Another method for amplification is the ligase chain reaction (“LCR”), disclosed in EPA No. 320 308, incorporated herein by reference in its entirety. In LCR, two complementary probe pairs are prepared, and in the presence of the target sequence, each pair will bind to opposite complementary strands of the target such that they abut. In the presence of a ligase, the two probe pairs will link to form a single unit. By temperature cycling, as in PCR, bound ligated units dissociate from the target and then serve as “target sequences” for ligation of excess probe pairs. U.S. Pat. No. 4,883,750 describes a method similar to LCR for binding probe pairs to a target sequence. Qbeta Replicase, described in PCT Application No. PCT/US87/00880, incorporated herein by reference, may also be used as still another amplification method in the present invention. In this method, a replicative sequence of RNA that has a region complementary to that of a target is added to a sample in the presence of an RNA polymerase. The polymerase will copy the replicative sequence that can then be detected. An isothermal amplification method, in which restriction endonucleases and ligases are used to achieve the amplification of target molecules that contain nucleotide 5′-[alpha-thio]-triphosphates in one strand of a restriction site may also be useful in the amplification of nucleic acids in the present invention. Strand Displacement Amplification (SDA) is another method of carrying out isothermal amplification of nucleic acids which involves multiple rounds of strand displacement and synthesis, i.e., nick translation. A similar method, called Repair Chain Reaction (RCR), involves annealing several probes throughout a region targeted for amplification, followed by a repair reaction in which only two of the four bases are present The other two bases can be added as biotinylated derivatives for easy detection. A similar approach is used in SDA. Target specific sequences can also be detected using a cyclic probe reaction (CPR). In CPR, a probe having 3′ and 5′ sequences of non-specific DNA and a middle sequence of specific RNA is hybridized to DNA that is present in a sample. Upon hybridization, the reaction is treated with RNase H, and the products of the probe identified as distinctive products that are released after digestion. The original template is annealed to another cycling probe and the reaction is repeated. Still another amplification methods described in GB Application No. 2 202 328, and in PCT Application No. PCT/US89/01025, each of which is incorporated herein by reference in its entirety, may be used in accordance with the present invention. In the former application, “modified” primers are used in a PCR-like, template- and enzyme-dependent synthesis. The primers may be modified by labeling with a capture moiety (e.g., biotin) and/or a detector moiety (e.g., enzyme). In the latter application, an excess of labeled probes are added to a sample. In the presence of the target sequence, the probe binds and is cleaved catalytically. After cleavage, the target sequence is released intact to be bound by excess probe. Cleavage of the labeled probe signals the presence of the target sequence. Other nucleic acid amplification procedures include transcription-based amplification systems (TAS), including nucleic acid sequence based amplification (NASBA) and 3SR Gingeras et al., PCT Application WO 88/10315, incorporated herein by reference. In NASBA, the nucleic acids can be prepared for amplification by standard phenol/chloroform extraction, heat denaturation of a clinical sample, treatment with lysis buffer and minispin columns for isolation of DNA and RNA or guanidinium chloride extraction of RNA. These amplification techniques involve annealing a primer which has target specific sequences. Following polymerization, DNA/RNA hybrids are digested with RNase H while double stranded DNA molecules are heat denatured again. In either case the single stranded DNA is made fully double stranded by addition of second target specific primer, followed by polymerization. The double-stranded DNA molecules are then multiply transcribed by an RNA polymerase such as 17 or SP6. In an isothermal cyclic reaction, the RNA's are reverse transcribed into single stranded DNA, which is then converted to double stranded DNA, and then transcribed once again with an RNA polymerase such as T7 or SP6. The resulting products, whether truncated or complete, indicate target specific sequences. Davey et al., EPA No. 329 822 (incorporated herein by reference in its entirety) disclose a nucleic acid amplification process involving cyclically synthesizing single-stranded RNA (“ssRNA”), ssDNA, and double-stranded DNA (dsDNA), which may be used in accordance with the present invention. The ssRNA is a template for a first primer oligonucleotide, which is elongated by reverse transcriptase (RNA-dependent DNA polymerase). The RNA is then removed from the resulting DNA:RNA duplex by the action of ribonuclease H (RNase H, an RNase specific for RNA in duplex with either DNA or RNA). The resultant ssDNA is a template for a second primer, which also includes the sequences of an RNA polymerase promoter (exemplified by T7 RNA polymerase) 5′ to its homology to the template. This primer is then extended by DNA polymerase (exemplified by the large “Klenow” fragment of E. coli DNA polymerase I), resulting in a double-stranded DNA (“dsDNA”) molecule, having a sequence identical to that of the original RNA between the primers and having additionally, at one end, a promoter sequence. This promoter sequence can be used by the appropriate RNA polymerase to make many RNA copies of the DNA. These copies can then re-enter the cycle leading to very swift amplification. With proper choice of enzymes, this amplification can be done isothermally without addition of enzymes at each cycle. Because of the cyclical nature of this process, the starting sequence can be chosen to be in the form of either DNA or RNA. Miller et al., PCT Application WO 89/06700 (incorporated herein by reference in its entirety) disclose a nucleic acid sequence amplification scheme based on the hybridization of a promoter/primer sequence to a target single-stranded DNA (“ssDNA”) followed by transcription of many RNA copies of the sequence. This scheme is not cyclic, i.e., new templates are not produced from the resultant RNA transcripts. Other amplification methods include “RACE” and “one-sided PCR” (Frohman, M. A., In: PCR PROTOCOLS: A GUIDE TO METHODS AND APPLICATIONS, Academic Press, N.Y., 1990 incorporated by reference). Methods based on ligation of two (or more) oligonucleotides in the presence of nucleic acid having the sequence of the resulting “di-oligonucleotide”, thereby amplifying the di-oligonucleotide, may also be used in the amplification step of the present invention. Following any amplification, it may be desirable to separate the amplification product from the template and the excess primer for the purpose of determining whether specific amplification has occurred. In one embodiment, amplification products are separated by agarose, agarose-acrylamide or polyacrylamide gel electrophoresis using standard methods (Sambrook et al., 1989). Alternatively, chromatographic techniques may be employed to effect separation. There are many kinds of chromatography which may be used in the present invention: adsorption, partition, ion-exchange and molecular sieve, and many specialized techniques for using them including column, paper, thin-layer and gas chromatography. C. Effective Polymerases Suitable polymerases are those DNA polymerases that demonstrate a relatively rapid rate of synthesis and can prime synthesis from a 3′ hydroxyl group. In certain aspects of the invention, polymerases having a 5′-3′ exonuclease activity to degrade one of the template strands are preferred. In other aspects of the invention, polymerases which possess strand displacement activity, whether or not they have 5′ to 3′ exonuclease activity, are preferred. And in particular embodiments, polymerases that have neither 5′ to 3′ exonuclease activity nor strand displacement activity are preferred. In principle, the enzymes for use in the present invention could have an associated 3′ to 5′ exonuclease (“proofreading”) activity, which might improve the ability to sequence very large molecules of DNA. All of the enzymes listed herein below (except Taq DNA polymerase, Tth DNA polymerase, Tfl DNA polymerase, Bst DNA polymerase, Ventr (exo), Deep VentR (exo), E. coli DNA polymerase I Klenow fragment and DNA polymerase I (pol I) from M. tuberculosis) seem to have this proof reading activity. Optimization of any of the polymerases listed herein below is contemplated in the present invention. Optimization of the polymerases involves testing different polymerases and mutants thereof under the conditions of the sequencing reactions. Indeed, rate of synthesis, fidelity of incorporation of natural nucleotides and nucleotide analogs, and length of the synthesized strands can be adjusted using standard methods (e.g. changing salt conditions, nucleotide triphosphate compositions and concentrations, temperature, time, etc.) known to those familiar with the art of sequencing. Directed mutagenesis of the polymerase is also well-known in the art. Such genetically engineered enzymes can be endowed with both the ability to tolerate a wider range of reaction conditions and improved sequencing product yield. With regard to genetically engineered enzymes, the present invention specifically contemplates polymerases modified according to the teachings of Tabor and Richardson, EP 0 655 506 B1, hereby incorporated by reference. Such modifications comprise mutations to the binding site which results in better incorporation of dideoxynucleotides (as compared to unmodified polymerases), while retaining other favorable activities. 1. Polymerases having 5′ to 3′ Exonuclease Activity In certain aspects of the present invention, polymerases having 5′ to 3′ exonuclease activity are preferred for use. Examples of polymerases known to have 5′ to 3′ exonuclease activity include, but are not limited to E. coli DNA polymerase I (Kornberg and Baker, 1992), DNA polymerase from Thermus aquaticus (hereinafter “Taq DNA polymerase”), which is a thermostable enzyme having 5′-3′ exonuclease activity but no detectable 3′-5′ activity (Longley et al., 1990; Holland et al., 1991), ΔTaq DNA polymerase (Barnes, 1992; commercially available from United States Biochemical), DNA polymerase I (pol A) from S. pneumoniae (Lopez et al., 1989), Tfl DNA polymerase from Thermus flavus (Akhmetzjanov and Vakhitov, 1992), DNA polymerase I (pol I) from D. radiodurans (Gutman et al., 1993), Tth from Thermus thermophilus (Myers and Gelfand, 1991), recombinant Tth XL from Thermus thermophilus (commercially available from Perkin-Elmer), DNA polymerase I (pol I) from M. tuberculosis (Hiriyanna and Ramakrishnan, 1981), DNA polymerase I (pol I) from M. thermoautotrophicum (Klimczak et al, 1986), wild-type (unmodified) T7 DNA polymerase (Hori et al., 1979; Engler et al., 1983, Nordstrom et al., 1981), and DNA polymerase I (UL30) from herpes simplex virus (Crute and Lehman, 1989). 2. Polymerases having Strand Displacement Activity In certain aspects of the invention, in addition to those polymerases listed above, polymerases that have strand displacement activity but lacking 5′ to 3′ exonuclease activity are preferred for use. Polymerases that lack 5′ to 3′ exonuclease activity include, but are not limited to, E. coli DNA polymerase I Klenow fragment (Jacobsen et al., 1974), modified T7 DNA polymerase (Sequenase®, commercially available from United States Biochemical; Tabor and Richardson, 1989, 1990), DNA polymerase large fragment from Bacillus stearothermophilus (commercially available from New England BioLabs), Thermococcus litoralis DNA polymerase (VentR® DNA polymerase, commercially available from New England BioLabs; Mattila et al., 1991; Eckert and Kunkel, 1991), Thermococcus litoralis DNA polymerase modified to eliminate the 3′ to 5′ exonuclease activity (VentR® (exo) DNA polymerase, commercially available from New England BioLabs; Kong et al., 1993), Pyrococcus species GB-D DNA polymerase (Deep VentR™ DNA polymerase, commercially available from New England BioLabs), Pyrococcus species GB-D DNA polymerase modified to eliminate the 3′ to 5′ exonuclease activity (Deep VentR™ (exo) DNA polymerase, commercially available from New England BioLabs), and ThermoSequenase® DNA polymerase (commercially available from Amersham). 3. Polymerases Effective with Gapped Templates In addition to those polymerases discussed above, polymerases such as T4 DNA polymerase, which do not have either 5′ to 3′ exonuclease activity or strand displacement activity, are effective polymerases in aspects of the invention where gapped templates are used. All polymerases capable of synthesis using a 3′ hydroxyl group as a primer are suitable for use in these aspects of the invention. 4. Engineered Polymerases Additionally, the present invention contemplates optimization of any of the polymerases listed herein above. Techniques for directed mutagenesis of DNA polymerases is well-known in the art. Such genetically engineered enzymes can be endowed with both the ability to tolerate a wider range of reaction conditions and improved sequencing product yield. With regard to genetically engineered enzymes, the present invention specifically contemplates polymerases modified according to the teachings of Tabor and Richardson, EP 0 655 506 B1, hereby incorporated by reference. Site-specific mutagenesis is a technique useful in the preparation of modified proteins or peptides, through specific mutagenesis of the underlying DNA. The technique, well-known to those of skill in the art, further provides a ready ability to prepare and test sequence variants, for example, incorporating one or more of the foregoing considerations, by introducing one or more nucleotide sequence changes into the DNA. Site-specific mutagenesis allows the production of mutants through the use of specific oligonucleotide sequences which encode the DNA sequence of the desired mutation, as well as a sufficient number of adjacent nucleotides, to provide a primer sequence of sufficient size and sequence complexity to form a stable duplex on both sides of the deletion junction being traversed. Typically, a primer of about 14 to about 25 nucleotides in length is preferred, with about 5 to about 10 residues on both sides of the junction of the sequence being altered. In general, the technique of site-specific mutagenesis is well known in the art, as exemplified by various publications. As will be appreciated, the technique typically employs a phage vector which exists in both a single stranded and double stranded form. Typical vectors useful in site-directed mutagenesis include vectors such as the M13 phage. These phage are readily commercially-available and their use is generally well-known to those skilled in the art Double-stranded plasmids are also routinely employed in site directed mutagenesis which eliminates the step of transferring the gene of interest from a plasmid to a phage. In general, site-directed mutagenesis in accordance herewith is performed by first obtaining a single-stranded vector or melting apart of two strands of a double-stranded vector which includes within its sequence a DNA sequence which encodes the desired polymerase to be modified. An oligonucleotide primer bearing the desired mutated sequence is prepared, generally synthetically. This primer is then annealed with the single-stranded vector, and subjected to DNA polymerizing enzymes such as E. coli polymerase I Klenow fragment, in order to complete the synthesis of the mutation-bearing strand. Thus, a heteroduplex is formed wherein one strand encodes the original non-mutated sequence and the second strand bears the desired mutation. This heteroduplex vector is then used to transform appropriate cells, such as E. coli cells, and clones are selected which include recombinant vectors bearing the mutated sequence arrangement. The preparation of sequence variants of the polymerase-encoding DNA segments using site-directed mutagenesis is provided as a means of producing potentially useful species and is not meant to be limiting as there are other ways in which sequence variants of polymerases and the DNA sequences encoding them may be obtained. For example, recombinant vectors encoding the desired polymerase sequence may be treated with mutagenic agents, such as hydroxylamine, to obtain sequence variants. Specific details regarding these methods and protocols are found in the teachings of Maloy et al., 1994; Segal, 1976; Prokop and Bajpai, 1991; Kuby, 1994; and Maniatis et al., 1982, each incorporated herein by reference, for that purpose. As one illustrative example of the protocols which are known to those of skill in the art for making mutants, the PCR™-based strand overlap extension (SOE) (Ho et al., 1989) for site-directed mutagenesis is particularly preferred for site-directed mutagenesis of the polymeraes to be modified. The techniques of PCR™ are well-known to those of skill in the art, as described herein. The SOE procedure involves a two-step PCR™ protocol, in which a complementary pair of internal primers (B and C) are used to introduce the appropriate nucleotide changes into the wild-type sequence. In two separate reactions, flanking PCR™ primer A (restriction site incorporated into the oligo) and primer D (restriction site incorporated into the oligo) are used in conjunction with primers B and C, respectively to generate PCR™ products AB and CD. The PCR™ products are purified by agarose gel electrophoresis and the two overlapping PCR™ fragments AB and CD are combined with flanking primers A and D and used in a second PCR™ reaction. The amplified PCR™ product is agarose gel purified, digested with the appropriate enzymes, ligated into an expression vector, and transformed into E. coli JM101, XL1-Blue™ (Stratagene, LaJolla, Calif.), JM105, or TG1 (Carter et al., 1985) cells. Clones are isolated and the mutations are confirmed by sequencing of the isolated plasmids. D. Extension In most aspects of the invention, an extension reaction is performed before termination. The extension reaction results in incorporation of deoxynucleotides and certain deoxynucleotide analogs. In a most general sense, a standard extension reaction includes each of the four “standard” deoxynucleotide triphosphates: dATP, dCTP, dGTP and dTTP, however, in certain embodiments of the invention, one, two or three deoxynucleotides are used in the extension reaction. Additionally, in certain preferred aspects described in detail herein, dUTP is included in the extension reaction (or in the primer for use in an amplification reaction) to provide a substrate for enzymes, such as uracil DNA glycosylase, to produce an abasic site at one or more positions in the nucleic acid. These abasic sites can be converted to nicks or breaks through heat, base treatment, or treatment with additional enzymes, such as endonuclease IV and/or endonuclease V. In other aspects of the invention described in detail herein below, one or more deoxynucleotide phosphorothioates or boranophosphates are included in the extension reaction. Another preferred aspect of the present invention concerns the use of one or more deoxynucleotide precursors that have a detectable label, or an isolation or immobilization tag. Preferred labels and tags are described in detail herein below. E. Termination In certain embodiments of the present invention, the Strand Replacement reactions are terminated by incorporation of a dideoxyribonucleotide instead of the homologous naturally-occurring nucleotide. This terminates growth of the new DNA strand at one of the positions that was formerly occupied by dA, dT, dG, or dC by incorporating ddA, ddT, ddG, or ddC. In principle the reaction can be terminated using any suitable nucleotide analogs that prevent continuation of DNA synthesis at that site. For certain applications, such as the determination of the length of telomeres, the polymerization reaction can be terminated when the polymerase cannot insert a particular nucleotide, because it is missing from the reaction mixture. Polymerization can also be terminated specific distances from the priming site by inhibiting the polymerase a specific time after initiation. For example, under specific conditions Taq DNA polymerase is capable of strand replacement at the rate of 250 bases/min, so that arrest of the polymerase after 10 min occurs about 2500 bases from the initiation site. This strategy allows for pieces of DNA to be isolated from different locations in the genome. F. Cleavage Because all of the template and synthetic DNA remains double-stranded, except at the site of termination, where there is a nick or small gap, restriction enzymes can be used to cut the DNA at sequence specific sites. At least one hundred of these cleavage reagents are commercially available and are able to make double-strand scissions in the DNA in short times. In addition to these natural sequence specific endonucleases there are a number of chemical reagents developed to make specific breaks in DNA (Strobel and Dervan, 1992; Grant and Dervan, 1996). G. Tags/Labels In preferred aspects of the invention, the nucleic acid template and/or the synthesized strand includes one or more detectable label and/or isolation or immobilization tag. Use of these labels and tags in a variety of different embodiments of the invention are detailed herein. 1. Isolation Tags In certain aspects of the invention, the nucleic acids comprise a tag that can be used to isolate and/or immobilize the nucleic acids having the tag. Affinity labels (e.g., biotin/streptavidin; hapten/antibody complexes, with common haptens being digoxigenin, fluorescein, BrdU; triplex-forming sequences, thiol groups, and sequence-specific DNA binding proteins (e.g., lac repressor)) are preferred in certain embodiments. Substrates used to immobilize the nucleic acids include, but are not limited to, surfaces of microwell plates, centrifuge tubes, streptavidin-conjugated paramagnetic particles, streptavidin-conjugated, filters, and chromatographic media containing thiol groups, metal ions, streptavidin, antibodies. 2. Detectable Labels Another embodiment of the invention comprises nucleic acids labeled with a detectable label. Label may be incorporated at a 5′ terminal site, a 3′ terminal site, or at an internal site within the length of the nucleic acid. Preferred detectable labels include a radioisotope, a stable isotope, an enzyme, a fluorescent chemical, a luminescent chemical, a chromatic chemical, a metal, an electric charge, or a spatial structure. There are many procedures whereby one of ordinary skill can incorporate detectable label into a nucleic acid. For example, enzymes used in molecular biology will incorporate radioisotope labeled substrate into nucleic acid. These include polymerases, kinases, and transferases. Preferably, the nucleic acids are labeled with one or more fluorescent dyes, e.g. as disclosed in U.S. Pat. No. 5,188,934 and PCT application PCT/US90/05565. In other aspects of the invention, affinity labels (groups that can be bound to detectable groups, e.g., biotin/streptavidin; hapten/antibody with common haptens being digoxigenin, fluorescein, BrdU, thiol groups) are used. Additionally, chemiluminescent and chemifluorescent labels, and enzymatic labels, such as alkaline phosphatase, glucose oxidase, luciferase, green fluorescent protein, β-glucuronidase and β-galactosidase are preferred in certain aspects of the invention. In other aspects of the invention, the labeling isotope is preferably, 32P, 35S, 14C, or 125I. The nucleic acids of the invention can be labeled in a variety of ways, including the direct or indirect attachment of radioactive moieties, fluorescent moieties, colorimetric moieties, and the like. Many comprehensive reviews of methodologies for labeling DNA and constructing DNA probes provide guidance applicable to constructing probes of the present invention. Such reviews include Matthews et al. (1988); Haugland (1992); Keller and Manak (1993); and Eckstein (1991); and Wetmur (1991). Additional methodologies applicable to the invention are disclosed in Connolly (1987); Gibson et al. (1987); Spoat et al. (1987); U.S. Pat. No. 4,757,141; U.S. Pat. No. 5,151,507; U.S. Pat. No. 5,091,519; Jablonski et al. (1986); and U.S. Pat. No. 5,124,246. Attachment sites of labeling moieties are not critical in embodiments relying on probe labels to identify nucleotides in the target polynucleotide, provide that such labels do not interfere with the strand replacement or nick formation steps. In particular, dyes may be conveniently attached to the end of the probe distal to the target polynucleotide on either the 3′ or 5′ termini of strands making up the probe, e.g. Eckstein (cited above), Fung (cited above), and the like. In some embodiments, attaching labeling moieties to interior bases or inter-nucleoside linkages may be preferred. The label may be directly or indirectly detected using scintillation fluid or a PhosphorImager, chromatic or fluorescent labeling, or mass spectrometry. Other, more advanced methods of detection include evanescent wave detection of surface plasmon resonance of thin metal film labels such as gold, by, for example, the BIAcore sensor sold by Pharmacia, or other suitable biosensors. II. Sequencing Methods In certain aspects, the present invention can be considered to be an improvement over the standard Sanger method of DNA sequencing. As noted above, the Sanger enzymatic method (i.e., dideoxy chain termination method) requires a DNA polymerase enzyme to elongate a short primer DNA that is hybridized to a single-stranded template. In other words, current Sanger DNA sequencing protocols require that double-stranded DNA for sequencing first be denatured to enable the primer to bind to the priming site (Murphy, 1993). By contrast, the present invention does not contemplate denaturation of the double-stranded template; rather, sequencing can be carried out directly on the double-stranded template. The Sanger technique involves 1) denaturation to generate single-stranded DNA, 2) hybridization of an oligonucleotide primer to a unique site of known sequence on the single-stranded DNA, 3) extension of the primer using Taq, T7, or other DNA polymerase to generate a double-stranded product, 4) termination of the synthesis at specific bases by using terminating agents [e.g., incorporating specific dideoxyribonucleotides (ddNTPs)], 5) denaturation of the double-stranded product, and 6) electrophoresis of the denatured DNA to separate the molecules by size. If synthesis is performed with all four dNTPs (nucleic acid precursors) and terminated with labeled ddATP then the strands synthesized will all begin with 5′ end of the primer and end at different positions where dideoxyriboadenosine has been incorporated in place of adenosine. In this case the distribution of fragment lengths reflect the spatial distribution of thymidine along the template strand. To determine the positions of each of the other three bases, separate reactions can be done to incorporate ddTTP, ddCTP, and ddGTP. For detection the synthetic DNA can be detected by hybridization, incorporation of labeled primers, incorporation of labeled nucleotides, or incorporation of labeled dideoxyribonucleotides. When fluorescently tagged dideoxyribonucleotides with different fluorescent spectra are used to terminate synthesis a laser can be used to distinguish between DNA molecules terminated with each of the four ddNTPs, such that only a single primer extension reaction and single electrophoresis lane needs to be run to determine the position of all four bases. An important disadvantage of the current Sanger method is that certain sequences (such as strings of guanine) are difficult to sequence due to the propensity of some sequences to form intramolecular and intermolecular secondary structure, which causes the polymerase to terminate prematurely or to add an incorrect dideoxyribonucleotide. In addition each sequencing reaction is only able to determine the sequence of only 400-800 nucleotides immediately adjacent to the primer. The present invention provides a method for overcoming both problems. The method of the present invention represents an enhancement of the Sanger Method. Using a suitable polymerase (described in more detail below), the present invention allows for the sequencing of undenatured, double-stranded DNA. In one embodiment, the process involves a controlled “nicking” of one strand of the double-stranded template followed by a strand replacement (SR). A. Specific Nicking 1. Nick Translation The strand replacement method of the present invention can be used to sequence a variety of templates. Such templates, include, but are not limited to, circular double-stranded templates and linear double-stranded templates produced by restriction or PCR™ amplification. a. Parallel Sequencing of Multiple Restriction Fragments from Circular DNA One embodiment of the invention is schematically shown in FIG. 1, FIG. 2, and FIG. 3. In this embodiment, the DNA to be sequenced is cloned into a special vector having the following features: 1) a relatively rare endonuclease recognition site (I-Sce I sites) on each side of the insert, 2) a single nick site (f1 gene II site) on one side of the insert such that the 3′ end of the nick is oriented toward the insert, and 3) the insert (i.e. the DNA to be sequenced). In this embodiment, no oligonucleotide primer is used. The f1 gene product II (hereinafter “gpII” or “f1 endonuclease”) produces a sequence specific, strand-specific nick that can prime DNA synthesis by E. coli pol I (Meyer and Geider, 1979). This process requires a core sequence of about 50 bp on the template DNA (Dotto and Zinder, 1984). In the presence of 5 mM Mg, gpII nicks about 50% of supercoiled plasmid and relaxes the other half. The entire f1 intergenic region is the origin of replication of f1 phage, and has been cloned into a number of commercially available vectors (e.g. pSPORT available from Life Technologies). A mutant gpII (G73A) has been cloned, overexpressed, and studied (Higashitani et al., 1992). This mutant protein has a relaxed requirement for plasmid supercoiling, produces mainly nicks rather than relaxed circles, and binds more cooperatively to the core site. The plasmid (FIG. 1) is first digested with an enzyme (e.g. the f 1 gene II product) which makes a strand-specific nick (i.e., a nick at one site on one of the stands of the double-stranded plasmid) at a specific recognition sequence, and then digested with the restriction enzyme corresponding to the endonuclease recognition sites (e.g., I-Sce I which is a commercially available 18-base specific endonuclease). Taq polymerase, dATP, dTTP, dGTP, and dCTP along with optimized concentrations of the four labeled (e.g. fluorescently-labeled) dideoxyribonucleotides ddATP*, ddTTP*, ddGTP*, and ddCTP* are added and a strand replacement reaction is begun to synthesize a new DNA strand (shown bold in FIG. 2) complementary to one strand of the template DNA. Whenever a ddNTP is incorporated into the DNA, the chain is terminated and labeled with the ddNTP complementary to the one strand of template (shown as large dots in FIG. 3). This produces a distribution of double-stranded fragments, shown in FIG. 3. These molecules are then denatured and a sequencing ladder generated using standard automated sequencing gels and ddNTP detection systems. In the case where the insert is too long to be sequenced on a single gel, the I-Sce I fragment can be cleaved (after reaction with Taq DNA polymerase) using other restriction enzymes. In the case shown in FIG. 3, two restriction enzymes (X and Y) produce eight restriction fragments to be sequenced. The overlapping sequences from the resolved restriction fragments will determine the entire sequence of the insert. Note that the restriction fragments can be resolved on double-stranded gels as bands of discrete length. The ability to fractionate DNA according to length is not affected by the presence of nicks in the double-stranded DNA. As noted above, it is well-known that double-stranded DNA with nicks or other flexible joints forms sharp bands during electrophoresis (Higashitani et al, 1992). Only at the step that a denaturing sequencing gel of each restriction fragment is performed will a ladder of bands at single-base intervals be produced. Alternative procedures could be used for many of the steps. The strand replacement reaction could be performed by a different polymerase, such as E. coli polymerase I. The restriction fragments produced by enzymes X and Y could be separated by capillary or slab electrophoresis. The ddNTP-terminated nucleic acids could be labeled with different colored dyes or with radioactivity. An example of the steps necessary to do the sequencing of a large insert would be: 1) make the nick with f 1 gene II product and cleave with I-Sce I; 2) add polymerase (e.g., Taq DNA polymerase) and nucleotide triphosphates (dNTPs and ddNTPs) for a fixed time; 3) restrict half of the sample with enzyme X and the other half with enzyme Y; 4) in parallel, separate the X and Y restriction fragments by capillary electrophoresis; 5) denature each of the isolated restriction fragments and sequence in a conventional sequencing apparatus. Steps 1-3 can be performed successively in the same tube. In principle, steps 4 and 5 could be done automatically within the sequencing device. b. Parallel Sequencing of Multiple Restriction Fragments from Linear DNA In one embodiment, the strand replacement method of the present invention is used to map the positions of bases along DNA of multiple restriction fragments. A double stranded DNA template is used (FIG. 4A). A nick is made in one of the strands (FIG. 4B). A strand replacement reaction is initiated (FIG. 4C). The products are generated in the presence of termination nucleotides (4 ddNTPs) (FIG. 4D) and elongation is thereby terminated (FIG. 4E). The products represent nucleic acid terminated at different sites (e.g. different adenine sites) (FIG. 4F). Two restriction endonuclease cleavage reactions of the products are performed with different enzymes (X and Y) (FIG. 4G). The restriction fragments are fractionated according to size (FIG. 4H). Thereafter, each fragment can be denatured and sequenced (FIG. 4I, illustrative results are shown for strand #4 from FIG. 4H) using conventional denaturing sequencing gels. c. Sequencing DNA Adjacent to a Series of Restriction Sites In certain cases, expected to occur often in DNA molecules less than about 5 kb in length, a number of restriction enzymes can be found that will cleave the DNA only once within the unknown sequence. In these cases only one restriction fragment will be formed, and sequencing can be performed directly, without size fractionation. This is illustrated in FIG. 5 for a circular plasmid having an insert containing a single Bam H1 site. Strand replacement begins at the nick site (f1 origin site) and proceeds clockwise. By making nicks in different strands, the sequences adjacent to the restriction sites in both directions can be determined. A double stranded strand replacement product can be subjected to digestions with different restriction enzymes. The products from each restriction digestion can be subjected to sequencing reactions to get sequence information from many sites. For example, after linearization with the restriction enzyme Bam H1, the products can be sequenced starting from the Bam H1 site. This method will also work with linear DNA as long as the end of the DNA behind the strand replacement polymerization is long enough (e.g. >1000 bp), such that the synthesized strand containing the sequences of the f 1 origin is too long to interfere with the bands produced adjacent to the restriction site. d. Bidirectional Sequencing Adjacent to a Series of Restriction Sites In another embodiment, both sides of a single internal restriction site (clockwise and counterclockwise) are sequenced in a covalently-closed circular DNA molecule. In the presence of ethidium bromide (Kovacs et al, 1984) many restriction endonucleases are able to nick DNA at the recognition site. After the initial nick, no further digestion takes place, so that most molecules have a single nick. Half of the molecules will have a nick in the top strand, and the other half a nick in the bottom strand. After removal of ethidium bromide using standard techniques, the mixed population of DNA molecules is subjected to the strand replacement sequencing reaction of the present invention. Those molecules nicked in the top strand will synthesize products in a clockwise direction; those nicked in the bottom strand will synthesize products in the counterclockwise direction. Those rare molecules that are not nicked or have undergone double-strand scission will not initiate the SR reaction. By controlling the reaction time the strand replacement sequencing reaction will be allowed to proceed long enough to progress about twice the critical length for sequencing by gel electrophoresis (˜2,000 bp). Some of the strands will terminate at ddNTP sites and others will terminate at ˜2,000 bp (for example). Alternatively after removing the ethidium bromide, the template DNA can be restricted at a rare restriction site located far from the insert that is being sequenced (the external restriction site). After the SR reaction, the products are cleaved again with the first restriction site, which cuts at the internal site, and also at the external site (if not cut previously). Now the sample consists of a mixture of two double-stranded restriction fragments, one carrying the strand replacement products synthesized clockwise from the internal restriction site and the second carrying the strand replacement products synthesized counterclockwise from the same internal restriction site. In principle, these fragments can be separated by molecular weight; however, because it is a binary mixture, any of a number of simpler, affinity techniques could be used. For example, the vector sequence to the left of the DNA insert can contain a sequence that will bind to a special triplex forming oligonucleotide or other sequence-specific DNA binding molecule (Hacia et al., 1994; Pilch et al., 1996; Trauger et al., 1996) that contains a chemical tag that can be affinity immobilized. The chemical tag allows for immobilization of the DNA binding molecule and attached DNA (in this case, the double-stranded restriction fragment to the left of the restriction site). In the case of a specific tag, such as a triplex-forming biotinylated oligonucleotide, one of the two double-stranded DNA molecules can be immobilized on a streptavidin-coated surface (e.g. beads). The free DNA can be loaded on the one lane of a sequencing gel and analyzed to sequence the bases located clockwise from the internal restriction site; the immobilizing surface (e.g. beads) can be washed to remove unbound DNA, denatured, and loaded on a different lane of the sequencing gel. Such separation has been used previously to separate strands of denatured PCR™-amplified DNA before conventional ddNTP sequencing reactions (Hultman et al., 1990; Lagerqvist et al., 1994). e. Sequencing of PCR™ Products PCR™ products can be subjected to the strand replacement method of the present invention. In one embodiment, PCR™ products are sequenced by incorporating special oligonucleotide primers for the PCR™ reaction that can be later processed to form a nick. For example, one of the two PCR™ primers can contain an f1 origin core sequence which can be cleaved with gpII (FIG. 7A). Alternatively, the PCR™ products can be subjected to treatments to degrade a few nucleotides from the 5′ termini [e.g., by use of T7 gene 6 exonuclease (FIG. 7C), or by cleavage of dUTP present in one of the primers (FIG. 7D)]. Subsequent hybridization of an oligonucleotide primer under non-denaturing conditions to the 3′ tail of the PCR™ products will produce the priming site necessary for initiation of strand replacement. Alternatively, an asymmetric PCR™ reaction can incorporate a phosphorothiolated nucleotide analog into one of the two DNA strands. Certain restriction enzymes are known to nick the normal strand of hemiphosphorothiolated DNA (Olsen et al., 1990), schematically represented in FIG. 7B. f. Microchip Oligonucleotide Array Sequencing Array sequencing involves hybridizing labeled unknown DNA to an array of oligonucleotides with different sequences. If a particular sequence (e.g., TTAGGG) occurs within the DNA, the array position having the CCCTAA oligonucleotide hybridizes to the unknown DNA, thereby immobilizing the label at a specific array position. By examining which array positions become labeled, a computer is able to reconstruct the sequence of the unknown DNA. The strand replacement method of the present invention provides a method for overcoming this limitation by producing groups of short DNA molecules at different distances from the gp II nick site, as shown in FIG. 9. In this figure, one embodiment of the method is shown for creating DNA different distances from the nick site. In this example, dUTP, dATP, dGTP, and dCTP are incorporated during an initial, variable period of the strand replacement reaction, followed by a fixed-time pulse of incorporation of dTTP, dATP, dGTP, and dCTP. The dTTP preferably is labeled (e.g., a radioactive label, a fluorescent label, or other suitable label). The incorporation of dUTP is done for variable times, whereas incorporation of dTTP is for a constant time, designed to allow synthesis of a stable oligonucleotide short enough to be used for oligonucleotide array sequencing located specific distances from the f1 nick site. After the strand replacement reaction, the dU bases are destroyed with deoxyribouracil glycosylase and heat, leaving the different samples of short, labeled nucleic acid bases to be sequenced on the microchip oligonucleotide arrays. This specific embodiment can be generalized to sequence DNA different distances from any strand replacement initiation site. 2. Primer Extension from Gap or Terminal Single-Stranded Region In certain embodiments of the invention, an oligonucleotide primer can be used to provide the free 3′ hydroxyl group to initiate the strand replacement reactions. The primers can be annealed to gaps formed in the nucleic acid, as described in detail herein, or to single-stranded regions at the end of the nucleic acid molecule. These single-stranded regions can be either naturally occurring, for example as found in telomeres, or created, preferably enzymatically, for example through the use of Bal 31 and T7 gene 6 exonuclease. 3. Ligation-Mediated Initiation Linear restriction fragments can be produced by restriction of cloned or PCR™ amplified DNA (FIG. 6, step 1). For illustrative purposes, the DNA in FIG. 6 has been cleaved with Bam HI at one end. To create an initiation point for strand replacement at one end of such a molecule, a special double-stranded adaptor DNA molecule is ligated to one end of the restriction fragment using a ligase (including, but not limited to E. coli ligase or T4 ligase) in such a fashion that a nick or one base gap is formed. This is achieved, for example, by dephosphorylating the 5′ ends of the restriction fragment (for example with calf intestinal phosphatase or shrimp alkaline phosphatase) before the ligation reaction (FIG. 6, steps 2 and 3), or by using a double-stranded oligonucleotide (FIG. 6, step 4) designed with a 3′ end one base shorter than required for ligation. The 3′ OH within the resulting nick or gap serves as the initiation point for the strand replacement reaction. Sequence information can be gained by analysis of the strand replacement products starting from one terminus or the other, using different nicking strategies for the two ends. In addition, cleavage with different restriction enzymes will allow sequencing to be “read” adjacent to different restriction sites. B. Random Break Incorporation Sequencing Random Break Incorporation (RBI) sequencing is distinguished from the Sanger method and all variations thereof by the fact that DNA synthesis is initiated at random sites and terminated after addition of only a few bases (in many cases the first base). The initiation of sequencing reactions at random breaks enables an entirely new concept of DNA sequence determination and analysis to be achieved. This new method involves determining and analyzing the sequence of dinucleotides, trinucleotides, and longer combinations of bases along DNA. Two distinct methods of determining multiple-base sequences are disclosed, the first method involving one or more steps of direct polymerization of nucleotides from the site of random breaks, and the second method involving an initial degradation step followed by one of more polymerization steps. These two methods use different reagents and reaction steps, yet achieve the same goal of determining the positions of multiple-base sequences along the DNA. Although the advantages of the multiple-base sequencing techniques are discussed in terms of dinucleotide sequencing, similar advantages are also found with trinucleotide, tetranucleotide, and longer nucleotide sequencing. Dinucleotide sequencing is the determination of the positions of each occurrence of a specific nucleotide pair (e.g., GC) in a DNA molecule. This is achieved by terminating the DNA strands with labeled specific nucleotide pairs. The dinucleotides are “read” after electrophoresis, mass spectrometry, or other size separation step, in the same way that the occurrence of single bases is “read” in the conventional Sanger or Maxim-Gilbert methods of sequencing. Dinucleotide sequencing is very powerful because it increases the length of DNA that can be sequenced in a single gel lane, and increases the accuracy of determination of the sequence. The length of DNA that can be sequenced in a single gel lane is determined by the maximum size of DNA for which successive bands of the sequencing ladder can be resolved. Successive bands on a single base sequencing gel can be separated by as little as one base. The current practical limits of gel electrophoresis restrict single-base resolution to DNA less than 500-1500 nucleotides, depending upon the type of electrophoresis apparatus used. In contrast, the positions of bands in a dinucleotide ladder can be no closer than two nucleotides. Therefore dinucleotides can be resolved in molecules up to 1000-3000 nucleotides. In practice, the average distance between each band in the dinucleotide sequencing ladder is 16 bases, which is 4 times greater than the average distance between bands in the single base sequencing ladder. This ability to read longer sequences using dinucleotide terminations greatly advances the progress and reduces the cost of DNA sequencing. Dinucleotide sequencing also increases the accuracy of sequencing by reading every base twice. For example, when the sequence AGC is present on the DNA, the central guanine will be read twice, once as the dinucleotide AG and once as the dinucleotide GC. In certain aspects of this method, dideoxyribonucleotides are not necessary for termination. The basic steps of RBI sequencing of DNA can be summarized as follows: Preparation of pools of double-stranded DNA molecules with identical sequence. This is achieved by direct isolation of the DNA, by cloning of DNA fragments in a suitable vector such as a virus, prokaryotic cell, or eukaryotic cell, or by amplification using primer extension, strand displacement, or polymerase chain reaction (PCR). An important feature of the DNA is that at least one 5′ terminus (or site near the 5′ end) is “tagged” with a chemical group for detection or immobilizing the DNA. Single- or double-stranded breakage of the DNA to create infrequent double- or single-stranded ends at random or substantially random locations. Degradation can be enzymatic (e.g., DNase I), chemical (e.g., hydroxyl radicals), or physical (e.g., hydrodynamic shear, freezing, or radiation). The defects must terminate or be made to terminate with a free 3′ hydroxyl end on the product strand, opposed to a complementary template strand. The use of randomly-located priming sites is a key, unique feature of the inventors' method to sequence DNA. All polymerases studied require 3′ ends with hydroxyl groups in order to incorporate new nucleotides. Therefore breaks in the DNA that do not originally contain 3′ OH groups have to be conditioned to possess 3′ OH groups before strand elongation can be done. One method to condition the 3′ end is to incubate the DNA in the presence of a 3′ exonuclease such as E. coli exonuclease III. This invention also contemplates the discovery or engineering of DNA polymerases able to remove nucleotides that do not have 3′ OH groups from the 3′ ends of DNA strands. Addition of one or more nucleotide bases to the 3′OH end the product strand, whereby the base(s) added is (are) complementary to the opposed base(s) on the template strand The base addition is catalyzed using a DNA polymerase capable of adding complementary bases using nucleotide triphosphates added to the reaction mixture. If a single dideoxyribonucleotide base is added, it will be added to 3′OH termini 0 or one times, depending on whether the dideoxyribonucleotide base is complementary to the opposed base on the template strand. If a single deoxyribonucleotide base is added to the reaction, it will be added to the 3′OH termini 0, 1, or more times for as long as the base is complementary to the template strand. As detailed herein, a succession of different complementary deoxyribonucleotide bases can be added by changing the deoxyribonucleotide triphosphates in the reaction buffer. The dideoxyribonucleotide or deoxyribonucleotide terminal bases are “tagged” such that if the 5′ end of the primer is tagged for detection, the base added to the 3′ termini of the product strands is tagged for immobilization; but if the 5′ end of the primer is tagged for immobilization the base added to the 3′ termini of the product strands is labeled for detection. When the primer is used for immobilization, several DNA molecules can be simultaneously prepared for sequencing by use of distinguishable immobilization tags. Separation of the DNA molecules by molecular weight and detection of those fragments that have both tagged 5′ ends and tagged 3′ ends. After the polymerization reaction some strands will have tagged 5′ ends, tagged 3′ ends, or both. Those strands with the immobilization tags will be retained on a surface or within a matrix, whereas those strands without the immobilization tags will be removed. The retained strands will be specifically mobilized and separated according to molecular weight by electrophoresis, chromatography, mass spectrometry, or other suitable technique, and identified by virtue of the detection tag. Therefore the only strands identified after size separation are those tagged for both immobilization and detection. If a single dideoxyribonucleotide or deoxyribonucleotide base has been added to the 3′ terminus of the product strands then the lengths of the identified DNA fragments (in nucleotides) will give the distance (in nucleotides) of that specific base from one end of the DNA molecule. Combining information about the lengths of the molecules that terminate with adenine, thymine, guanine, and cytosine will give the base sequence of the DNA molecule. These results are similar to the results of the Sanger Sequencing method, and can be called “single-base sequencing.” When a succession of different nucleotide bases are added to the 3′OH ends the molecular weights of the detected fragments will represent the positions of specific strings of bases along the DNA (e.g., AnTmCo, where n is the number of successive A residues, m is the number of successive T residues, and o is the number of successive C residues). The results of this approach can be called “multiple-base sequencing.” Random breaks can also be used for sequencing by degradation rather than synthesis at random sites. In this variation, the DNA to be sequenced contains a degradation resistant base, such as an αS dNTP. After random degradation of the DNA, an exonuclease is used to degrade the strand up to the resistant base. This example (called random break degradation sequencing) is discussed further in this disclosure herein below. The principle of Random Break Incorporation sequencing can be implemented in a number of ways, using different methods for preparing the DNA fragments, degrading the DNA, tagging the DNA, incorporating nucleotides, and separating the products. The inventors will not detail all alternatives to each of the fundamental steps, but will give three main examples designed to achieve single-, double-, and n-base sequencing. In every case the protocols share the common step of priming DNA synthesis at random breaks in the DNA, in contrast to the Sanger method which primes DNA synthesis at unique sites. 1. One Base Sequencing a. Single-Base Sequencing Using Single-Strand Breaks The strands to be used for sequencing must terminate at a unique site at their 5′ ends, and a plurality of base-specific sites at their 3′ ends. This can be achieved using multiple strategies. For example, a tag can be incorporated at the 5′ end for purposes of detection of the molecule and a different tag incorporated at the 3′ end to physically separate the molecules from those that have not been tagged at the 3′ ends. Alternatively the separation tag can be placed at the 5′ end and detection tag at the 3′ end. For purposes of this disclosure the inventors have described physical separation as immobilization on a surface or in a matrix by well-established techniques. In principle other techniques of separation, including but not limited to electrophoresis, chromatography, centrifugation, or enzymatic processing can also be employed. Single-Base Sequencing Employing 5′ Tags that can be Detected and 3′ dideoxy nucleotides with Tags that can be Immobilized In this first example, the inventors describe the case of detecting the strands with a 5′ tag and separation by immobilization of the strands with a 3′ tag. The steps of processing the DNA are illustrated in FIG. 15, with the results on sequencing gels shown in FIG. 16. Preparation of Tagged DNA Molecules for Sequencing A DNA sequence can be amplified by PCR using two primers, complementary to bases at both ends of the DNA to be sequenced. One of those primers is tagged for detection using one or more fluorescent, radioactive, or chromogenic chemical groups. Detectable primers are available from commercial sources or can be synthesized in individual laboratories. To facilitate later cleavage of the DNA special nucleotide analogs (e.g., dU) can be incorporated into one or both strands during amplification. Tagged DNA molecules can also be produced from cloned DNA. For example, restriction at a site adjacent to the insert DNA can be followed by radioactive labeling of the 5′ terminus using kinase or ligation of a detectable oligonucleotide. Alternatively a site in the vector sequence can be nicked using f1 endonuclease, tagged by incorporation of detectable nucleotides using nick-translation, followed by ligation and recleavage with f1. Random Breakage of DNA to Create Priming Sites for DNA polymerase Random breaks are introduced into one or both DNA strands using reagents familiar to molecular biologists. For example, DNase I used under different conditions can produce nearly random double-strand or single-strand breaks. These enzymes produce 3′OH groups that can serve as priming sites. Single-strand breaks can also be produced using hydroxyl radicals generated by a number of methods including Fe2+/EDTA/H2O2 or gamma irradiation. The primary products of radical cleavage are randomly-positioned nicks or gaps, usually with 3′ phosphate groups. Therefore the DNA must be processed before the sites can be used to prime DNA synthesis. After creation of a low frequency of defects, a suitable phosphatase (e.g., alkaline phosphatase or T4 kinase in the absence of ATP) or a 3′ exonuclease (e.g., exo III) is used to create 3′ OH groups at the site of the defects. Each of these 3′OH ends constitutes a potential priming site for DNA synthesis. Single-strand breaks can also be made by freezing and thawing DNA, and perhaps by hydrodynamic shear. Addition of Complementary Base at the Site of the Defects A DNA polymerase without 3′ exonuclease activity (e.g., Taq) and a mixture of one or more normal or terminating deoxyribonucleotide triphosphates will be added. FIG. 15 shows the outcome when biotinylated ddTTP is used as the nucleotide triphosphate. All strands having 3′ ends opposite adenine in the template strand will be biotinylated, whereas those terminating in adenine, guanine, or cytosine will not contain a 3′ biotin. The specificity to the reaction can be optimized, if necessary, by adding non-biotinylated ddATP, ddCTP, and ddGTP to the reaction mix to reduce the probability that the biotinylated ddTTP will be misincorporated at the 3′ ends. Separation of the DNA Molecules Tagged at the 3′ Ends FIG. 15 shows that the reaction contains fragments terminated with biotinylated thymine at the 3′ ends, as well as strands without biotinylated bases at the 3′ ends. The strands having biotin will be immobilized using streptavidin-coated magnetic particles, beads, or other surface. The low frequency of defects will ensure that most strands will have only a few biotin moieties. The surface will then be washed under conditions that denature the DNA strands but do not release the strands tagged with biotin (e.g., 30 mM NaOH). After all non-immobilized strands of DNA are removed, the immobilized strands can be released by reversing the streptavidin-biotin linkage (e.g., heating in the presence of SDS). Biotin can be used as a separation tag because of its high affinity for streptavidin. However alternative moieties can be used for separation. For example, digoxigenin can be used because it can be immobilized using specific antibodies, or a sulfhydryl group can be used because it can be immobilized by oxidation with other sulfhydryl groups. Size-Separation and Detection of the DNA Molecules Tagged on Both Ends To determine the position of the tagged dideoxythymidine nucleotides along the DNA, the released molecules must be separated according to size (e.g., by electrophoresis on a standard sequencing gel) and the strands having tagged primer DNA at the 5′ ends detected on the basis of fluorescence, absorbance, or emission of light, an enzymatic reaction, or detection of radiation. The sequencing ladder produced after incorporation of the ddTTP (FIG. 15) will have bands representing the positions of every thymine in the product strand, analogous to the sequencing ladders found by the Sanger Method. In order to determine the positions of all four bases, four reactions are performed using primers tagged with the same detectable moiety followed by electrophoresis of the products of the four reaction in separate electrophoretic lanes, as shown in FIG. 16. Alternatively the four reactions incorporating the four dideoxynucleotide bases can employ four distinguishable primers (e.g., four different fluorescent dyes) and the products combined into a single gel lane followed by differential detection of the products of the four reactions. Combining the information in all four lanes or from the differentially detected bands in one lane, the exact base sequence will be determined, as shown in FIG. 16. Single-Base Sequencing Employing 5′ Tags that can be Detected and 3′ deoxyribonucleotides with Tags that can be Immobilized The necessary 3′ tags can also consist of normal deoxyribonucleotides, as shown in FIG. 17 and FIG. 18. All steps are the same as explained herein above, with the exception that the each polymerization reaction is done in the presence of a single normal deoxyribonucleotide. FIG. 17 shows the case where tagged dTTP is used for the reaction. The sequencing ladder (shown in FIG. 18) will have bands representing the positions of the ends of every succession of one or more thymines in the product strand, similar to the sequencing ladders found by the Sanger Method, except having gaps wherever there is a string of more than one thymine. By combining information from reactions terminated with dTTP, dCTP, dGTP, and dATP, the identity of bases in the gaps of the electropherograms will be the same as that of the base at the 3′ end of the gap. For example if guanine is present at base positions 7-8, there will be a guanine band at position 8 adjacent to a gap at position 7. A guanine at position 7 is inferred from the lack of a thymine, cytosine, or adenine band at that position and the presence of a guanine at position 8. Thus the complete base sequence can be determined. Single-Base Sequencing Employing 5′ Tags for Separation and 3′ Tags for Detection The role of the tags at the 3′ and 5′ ends can be reversed, which results in less flexibility in design of the tag for detection, but greater flexibility in the tag used for separation. In certain aspects of the present invention, 5′ immobilization tags and 3′ detection labels are preferred. FIG. 19 shows the situation when the 3′ end of the product DNA has been labeled for detection by incorporation of a detectable base analog and the primer has been tagged with biotin for immobilization. In this case the DNA molecules are first immobilized via the biotin or other immobilization moiety at the 5′ end of the product strand. Other moieties can be used for immobilization, such as digoxigenin, SH groups, or triplex-forming sequences incorporated into a PCR primer or incorporated into the 5′ end of the product strand. The procedures for degrading the DNA, priming synthesis, and size separation have been described herein. Subsequently the DNA is denatured and all the non-biotinylated strands removed by washing. The strands containing the tagged primer can be specifically released using conditions necessary to reverse the biotin-streptavidin bond or by cleaving the primer at an internal site by enzymatic or chemical means. For example, if dUTP has been incorporated into the 5′ end of the molecules it can be degraded using uracil glycosylase in combination with enzymes such as endonuclease IV or endonuclease V, base treatment or heat, preferably endonuclease V. Alternatively, if a ribonucleotide is incorporated into a specific location in the primer, cleavage can be effected by raising the pH. Also, a restriction endonuclease recognition site can be engineered into the primer, serving as a substrate to form a break. The released strands will be separated on the basis of molecular weight. If labeled ddTTP has been incorporated by DNA polymerase, then the ladder of fragment lengths will correspond to the positions of every thymine along the product DNA strand. Four such ladders can be produced from four separate reactions with each the four different ddNTPs, as shown in FIG. 20. Combining the information in all four ladders will completely determine the base sequence of the DNA. Alternatively if the polymerization reaction has been performed with four ddNTPs with distinguishable labels (as a combined reaction or as four separate reactions) then the sequence of all four bases can be determined by distinguishing the different labels within a single ladder. Of course sequencing can also be done by incorporation of deoxyribonucleotides at the 3′ ends, as shown in FIG. 17 and FIG. 18. 5 b. Single-Base Sequencing at Random Double-Strand Breaks All these approaches can be performed on DNA having double-strand breaks by using a DNA polymerase with “proofreading” 3′ exonuclease activity, such as T4 DNA polymerase or E. coli Klenow fragment. After breakage the DNA might have a very short 3′ overhang, 5′ overhang, blunt, or a mixture of terminal structures. Any of these ends will serve as substrate for the proofreading DNA polymerase. If a specific tagged ddNTP and the three remaining, untagged dNTPs are added the polymerase will add the dideoxyribonucleotide base at the first complementary position adjacent to the break. The base-specific tag can then be used for sequencing as proposed herein. If, instead, four ddNTPs with distinguishable tags are simultaneously added to the reaction, the polymerase will incorporate all four at complementary terminal positions. C. Sequencing Starting from Base-Specific Single-Strand Breaks It is not necessary to break the DNA at totally random sites. For instance, if a cleavage-sensitive base analog is incorporated into one or both DNA strands during synthesis these base positions can later be cleaved. For example, if a small fraction of the thymines are replaced by deoxyribouridines during PCR amplification, those sites can be converted to one base gaps by the concerted action of dU glycosylase and endonuclease V. Separation of the DNA according to molecular weight will give the sizes of all DNA molecules terminated before thymine. Addition of a polymerase and ddTTP or dTTP will tag the thymine-containing sites. To label the DNA at sites containing any of the other three bases a combination of three normal dNTPs and one ddNTP can be used. For instance, to label the DNA at guanine, polymerase plus dTTP, dATP, dCTP, and ddGTP can be added. 2. Two Base Sequencing This technique allows the display of all positions of a specific doublet of bases. Determination of the positions of the 12 possible doublets with non-identical bases will give sufficient information to determine the sequence of every base. As above, the 5′ ends can be tagged for immobilization or detection, and the 3′ terminal bases can be tagged for detection or immobilization, respectively. The only step different from those presented for single-base sequencing is the polymerization step, which must achieve the sequential addition of two bases. The method for doing this is shown in FIG. 21 for the determination of the positions of the doublet TA. In this example the DNA is assumed to be immobilized via a tag on the 5′ end of the PCR primer strand and detected via a tag incorporated onto the 3′ end of the product strand. In principle, the positions of the tags for immobilization and detection can be interchanged. The DNA is first isolated, immobilized, and randomly degraded as outlined above. Next, the immobilized DNA is incubated in the presence of DNA polymerase and the dideoxyribonucleotides ddATP, ddGTP, and ddCTP. This will block every 3′OH end that incorporates any of those bases (i.e. those opposite T, C, or G in the template strand). However, all ends opposite A in the template strand will remain unblocked, that is still available to prime DNA synthesis. After removal of the ddNTPs by washing, dTTP and polymerase are added to the immobilized DNA in order to add one or more thymidines to the unblocked 3′OH ends opposite one or more adenines on the template strand. One such cycle of blocking the ends opposite three of the bases and incorporating one or more nucleotides opposite the fourth base is called a “walk,” in this case a “T-walk,” because thymine is added to the free 3′OH ends. The unincorporated dTTP is then removed by washing, and polymerization continued with DNA polymerase and ddATP tagged for detection. The tagged adenine dideoxyribonucleotide will only be incorporated at the unblocked 3′OH ends opposite thymidine on the template strand. This second step is therefore called an “A-termination.” The samples are then subjected to conditions that denature the DNA and washed to remove all fragments that are not immobilized via the 5′ tags. Subsequently the 5′ tagged strands are released by reversing the link used to immobilize the 5′ tagged DNA and separated according to size by electrophoresis or other suitable method. Detection of all fragments with the 3′ tags will produce a ladder of fragment lengths representing all positions of the TA doublet, as shown in FIG. 21. This technique can be used to map the positions of known important doublets such as CG in order to localize CG islands that precede many genes, to locate and measure the length of repetitive DNA tracts (e.g., doublet and triplet repeats involved with genetic diseases), or to sequence DNA. In order to determine the complete DNA sequence the information from all 12 possible hetero-nucleotide doublets can be combined to determine the position of each (as shown in FIG. 22). The sequence of the DNA in regions where homo-nucleotide strings (e.g., AAA) are present can be inferred from the nature of the doublets adjacent to the gaps. Double-base sequencing has advantages over single-base sequencing in that: 1) the sequence is determined with two-fold redundancy, increasing the accuracy of base assignments, and 2) the base sequence can be determined for longer pieces of DNA, because the bands present in the electropherograms are separated by 2 or more nucleotides and thus can be distinguished over a wider range in molecular size than if single-base resolution is required. Thus the “read-length” of the DNA sequencing gels should be significantly longer than possible with single-base sequencing. Doublet sequencing requires the use of only eight polymerization solutions, each containing DNA polymerase, but differing in the nucleotide triphosphates. 3. Three Base Sequencing and N-Base Sequencing The base walking method described in section 1,c can be extended to determine the location of any succession of bases. For example, a succession of three bases can be symbolized by the string XaYbZc, where X, Y, and Z are types of bases with the properties that X is a different base than Y, Y is a different base than Z, and a, b, and c, are the number of sequential bases of the type X, Y, and Z, respectively. FIG. 23 shows the example determining the positions of the nucleotide succession TaAbT using a two-base walk and a one-base termination. In this example the DNA is assumed to be immobilized via a tag on the 5′ end of the PCR primer strand and detected via a tag incorporated onto the 3′ end of the product strand. In practice, the positions of the tags for immobilization and detection can be interchanged. The DNA is first isolated, immobilized, and randomly degraded as outlined above. The DNA can be immobilized before, during, or after any of these steps. Next, the immobilized DNA is incubated in the presence of DNA polymerase and ddATP, ddGTP, and ddCTP to block every 3′OH end opposite T, C, or G in the template strand. After removal of the ddNTPs by washing, dTTP and polymerase are added to the immobilized DNA in order to add one or more thymidines to those unblocked 3′ ends opposite one or more adenines on the template strand. This completes the first “T-walk.” The unincorporated dTTP is then removed by washing. The immobilized DNA is then reacted with DNA polymerase and ddCTP, ddGTP, and ddTTP to block all 3′ ends except those opposite thymidine on the template strand. (ddTTP normally cannot be incorporated, but is included to minimize the number of different reaction mixtures necessary to complete all steps). After completion of the reaction the ddNTPs are removed by washing. Next, the immobilized DNA is reacted with DNA polymerase and dATP to added one or more adenosines to every 3′OH end that is opposite a thymine in the template strand. This completes the “A-walk.” Finally, tagged ddTTP is added and the reaction with DNA polymerase continued to add a single thymine dideoxyribonucleotide to those unblocked 3′OH ends that are opposite thymidine in the template strand. This completes the “T-termination.” The samples are then subjected to conditions that denature the DNA and washed to remove all fragments that are not immobilized via the 5′ tags. Subsequently the 5′ tagged strands are released by breaking the link used to immobilize the 5′ tagged DNA and separated according to size by electrophoresis or other suitable method. Detection of the 3′ tags will produce a ladder of fragment lengths representing all positions with the 3-base succession TaAbT, where a and b are integers greater than zero. This method can be modified slightly to detect all occurrences of TaAbTc by substituting tagged dTTP for tagged ddTTP at the terminal “T-termination” step. By “walking” a number of steps before addition of the tagged nucleotides the positions of any succession of an arbitrary number of bases can be determined, e.g., TaAbTcGdCeG. The complete sequence of the DNA can be determined with almost n-fold redundancy by analyzing the results of all possible combinations of walks (e.g., 36 reactions for 3-base sequencing). N-base sequencing requires the use of only eight polymerization solutions, each containing DNA polymerase, but differing in the nucleotide triphosphates. 5. Sequencing of Multiple Restriction Fragments After a Single Random Break Incorporation Reaction The examples of Random Break Incorporation described above employ immobilization to separate one strand to be sequenced from other strands in order to sequence one piece of DNA immediately adjacent to the primer. However because the DNA remains double-stranded after the polymerase reaction, the DNA can be cleaved with restriction enzymes and separated into many fragments that can be sequenced according the procedures shown herein above, or using other techniques. As the result very long pieces of DNA can be sequenced without the need to subclone DNA. 6. Application of RBI Sequencing to Double-Stranded RNA or RNA-DNA Hybrids In principle any double-stranded nucleic acid can be sequenced using the above techniques, using appropriate RNA-dependent DNA or RNA polymerases and appropriate nucleotide triphosphates. Such sequencing might be useful for determination of the sequences of RNA virus genomes, and products of RNA polymerase or reverse transcriptase. C. Primer-Based Sequencing Methods Initiation can also be accomplished with an oligonucleotide primer. Such methods include, but are not limited to 1) introduction of one or more oligonucleotide primers at the end or within the template DNA by local disruption of the DNA helix, and 2) introduction of one or more oligonucleotide primers at the end or within the template DNA by removal of a few bases from one strand (e.g. by digestion of the end of DNA by T7 gene 6 exonuclease). D. Random Break Degradation Sequencing The present invention provides another powerful method to create DNA molecules that terminate at a specified base. This method employs strand degradation rather than polymerization. The general principle involves incorporation of a degradation-resistant base analog at selected positions in a DNA strand, followed by exonuclease or chemical degradation to produce molecules terminated at the selected base. Separation of the DNA strands according to molecular weight produces a Sanger-like ladder of fragments that terminate at positions that have incorporated the base analog. This method has been employed by substituting deoxyribonucleoside phosphorothioates (Labeit et al., 1986, 1987; Nakamaye et al., 1988; Olsen and Eckstein, 1989) or deoxyribonucleoside boranophosphates (Porter et al., 1997) at a fraction of the sites for a specific base. This incorporation can be done, for example, during PCR amplification by adding one boronated or thioloated deoxyribonucleotide triphosphate along with the 4 normal deoxyribonucleotide triphosphates. Subsequent degradation of the strand with snake venom phosphodiesterase and/or exonuclease III (exo IlI) causes the 3′ end of the strand to be degraded until the boronated or thiolated linkage is reached. Alternatively chemical degradation of the thiolated linkages are able to terminate the strands at base-specific breaks. These methods for degrading DNA to produce sequencing ladders are related in principle to the Maxim-Gilbert methods of sequencing by chemical degradation using base-specific chemicals. However, despite the apparent simplicity of the degradative methods for sequencing, they are not commonly used to sequence DNA. Chemical degradation is not ideal because of the sequence specificity of the reactions and background cleavage at non-specific sites. Exonuclease degradation is not ideal because the 3′ termini can have mixed chemical. composition, and exonucleases can have difficulty degrading long strands of DNA without sequence-specific accumulation or “read-through” of certain termination sites. As a result the sequencing ladders can have extra bands or missing bands, and the band intensities are not uniform (Porter et al., 1997). Initiating the exonuclease digestions from random breaks overcomes these difficulties by overcoming the need to do long-distance exonuclease degradation. In addition, degradation from random sites followed by DNA polymerization can be used to achieve dinucleotide, trinucleotide, and n-nucleotide sequencing. The application of random break degradation to sequencing of single nucleotides is described first. PCR amplification is used to incorporate a resistant base analog into a fraction of the normal base positions in the DNA. Different fractions of incorporation of the resistant base have utility in various aspects of the invention, from incorporation of a single resistant base analog to 100% incorporation. In principle any base analog partially resistant to exonuclease degradation (such as phosphorothiolates or boranophosphates) can be used. As in previous applications one of the strands can be tagged by the use of a labeling or immobilization moiety attached to one of the primers. Alternatively both strands can be differentially labeled or immobilized using distinguishable chemical moieties on the two primers. Random single- or double-strand breakage by any of the methods previously described for Random Break Incorporation sequencing will produce a distribution of molecules cleaved at every or nearly every base site. Alternatively, deoxyribouracil can be incorporated at a fraction of the thymine base sites during PCR amplification, in the presence of dATP, dCTP, dGTP, dTTP mixed with a small amount of dUTP. These molecules can be cleaved by incubation with dU glycosylase and endonuclease IV (endo IV) or endonuclease V (endo V). Treatment of the DNA with exo III, snake venom phosphodiesterase, or other exonuclease that pauses or stops when reaching the resistant base will produce a spectrum of fragments terminated at resistant bases at the 3′ ends. Those fragments with tagged 5′ ends and specifically terminated 3′ ends can be separated by immobilization of the 5′ immobilization tags, or specifically identified by detection of the 5′ labeled tags. When immobilization tags have been used the molecules with specific 5′ ends can be immobilized on a surface, washed free of other molecules, released into solution by reversal of the attachment to the surface, and separated according to size by electrophoresis, mass spectrometry, or other method. When the primers have been labeled with fluorescent, radioactive, or other detectable groups, the mixture of all fragments can be separated according to size and the molecules with tagged 5′ ends that are terminated at the resistant bases can be detected in order to determine the positions of the resistant base analogs relative to the end of the original amplified DNA. By repeating this process with each of the four resistant base analogs, the entire sequence of the amplified DNA can be determined. Random break degradation can also be used as the first step in dinucleotide, trinucleotide, and n-base sequencing. For example, to determine the positions of all dinucleotides of the sequence AT, PCR products are created having one tagged primer (able to be immobilized) and a fraction (e.g., 10-100%) of the adenines replaced by phosphorothiolated adenine. Random single- or double-strand breakage of the DNA followed by exonuclease treatment produces the spectrum of tagged DNA strands terminating with adenine. Addition of labeled ddTTP and DNA polymerase selectively labels those fragments that terminate with AT. When ddATP is added with polymerase, fragments terminated with AA are labeled. When resistant ddNTPs are used, the exonuclease does not need to be inactivated or removed before adding the polymerase. In the absence of resistant ddNTP analogs, the exonuclease can be removed by washing, inactivated by heating, or inhibited by changing ionic conditions or by adding a chemical inhibitor. The tagged fragments are immobilized at any time during this process, washed free of the fragments with untagged 5′ ends, size-separated by electrophoresis or other means, and the labeled terminal bases detected by fluorescence, radioactivity, or other means to determine the distances of the selected dinucleotides from one end of the amplified DNA molecules. When all four ddNTPs with distinguishable fluorescent labels are used, four dinucleotide sequences (e.g., AA, AT, AC, and AG) can be determined from the same nuclease/polymerase reaction and size-separation. Analysis of all 16 dinucleotide sequence combinations allows reconstruction of the complete nucleotide sequence of the DNA molecule. The advantages of this method of determining dinucleotide sequences (relative to the dinucleotide sequencing produced by polymerization without degradation) include: the dinucleotide sequence can be determined with only a single polymerization reaction; and the positions of homodinucleotides (e.g., AA) can be determined. Determination of trinucleotide and n-nucleotide sequences can be determined by adding one or more cycles of nucleotide “walks” between the exonuclease degradation step and the termination step. Multiple base sequencing by random break degradation has an additional advantage over existing methods of sequencing by degradation in that only those molecules that have been degraded to leave a 3′ OH terminus will become labeled and therefore will be detected. Those molecules that have been degraded to other chemical sites will not be extended by DNA polymerase and therefore will not be labeled and detected, thus reducing background. Further aspects of this method involve the direct sequencing of the degraded products, without base addition, and incorporation of four nondiscriminating ddNTPs to make the products of the degradation reaction suitable for direct sequence analysis. E. Polymerases In principle any DNA polymerase can be used under a wide variety of conditions so long as the polymerase can 1) initiate synthesis at the 3′ end adjacent to the DNA break, 2) incorporate nucleotide bases complementary to the opposed, template strand, and 3) terminate synthesis at a selected base. Different polymerases are required to carry out the reaction under different circumstances, including the nature of the break and nature of the terminating base. For example, if the break consists of a single-strand nick, the polymerase must have a 5′ to 3′ exonuclease activity, a strand displacement activity, and/or a 3′ to 5′ exonuclease activity in order to incorporate new nucleotides onto the 3′ end. For incorporation of nucleotides during a net synthesis of DNA to move the 3′ end forward to elongate the synthesized strand, enzymes exemplified by, but not limited to, T. aquaticus (Taq) DNA polymerase, M. tuberculosis DNA polymerase I, and other polymerases with 5′ exonuclease activity can elongate the strand by adding new nucleotides to the 3′ end while degrading existing nucleotides from the 5′ end. These enzymes can incorporate bases at single-strand nicks and gaps. Enzymes such as E. coli DNA polymerase I Klenow fragment, Sequenase (modified T7 DNA polymerase), Thermosequenase, Vent DNA polymerase, and other many other enzymes without 5′ exonuclease activities can incorporate new nucleotides by displacing the DNA on the 5′ side of a nick or gap in the DNA. Enzymes such as T4 polymerase that lack 5′ exonuclease activity and strand displacement activity require a gap in the DNA in order to elongate the 3′ end. In contrast to all the reactions that produce net synthesis of DNA at the 3′ end (described in detail herein), polymerases with proofreading activities are also able to terminate synthesis after removing one or more nucleotides from the 3′ ends. For example, Vent DNA polymerase, E. coli DNA polymerase I, E. coli DNA polymerase I Klenow fragment, and T4 polymerase have proofreading activities that can remove bases from the 3′ ends and replace them with new nucleotide bases. The removal reactions are favored at low concentrations of deoxyribonucleotide triphosphates, and the polymerization reactions are favored by high concentrations of the nucleotide triphosphates. During these nucleotide replacement reactions the strands can be made to terminate at selected bases by 1) incorporation of selected dideoxyribonucleotides or 2) termination due to addition of only three of the four natural nucleotides such that all strands terminate one base before the selected base. These replacement synthesis reactions are especially valuable for terminating DNA synthesis at selected bases near the site of double-strand breaks, because a template strand is not available for strand elongation from the site of the break. F. Detection Methods Separation of sequence-specific double-stranded DNA fragments can be achieved by fractionation according to size using electrophoresis through media, including agarose, polyacrylamide, and polymer solutions. The physical form of the media can include flat layers, tubes and capillaries. Size fractionation can also be achieved by flow of solution through chromatographic media by the techniques of HPLC and FPLC. Mass spectroscopy is also contemplated for use in certain embodiments. The ability to fractionate DNA according to length is not affected by the presence of nicks in the double-stranded DNA. For example, it is well-known that nicked double-stranded DNA forms sharp bands during electrophoresis (Higashitani et al., 1992). Preparative collection of the DNA after separation can be performed manually by cutting pieces from gels, allowing the samples to flow into collection vessels, or by automatically sorting liquid samples. Typically, the fractions containing DNA fragments are detected by absorption spectrophotometry, fluorescence, radioactivity, or some other physical property. In specific cases size fractionation before sequencing gels is not required for sequencing a specific restriction fragment. These cases include those where (a) only one restriction site is present in the DNA to be sequenced, (b) only one restriction fragment is long enough or short enough to give a good sequencing gel, and (c) two restriction fragments are produced, but one is removed from the reaction using an affinity immobilization or separation, e.g., based on the presence of biotin, digoxigenin, or a triplex-forming nucleotide on one of the fragments that leads to immobilization on magnetic beads, surfaces, or matrices, and d) only one restriction fragment is labeled. Chip-Based Methods The present invention contemplates carrying out the novel sequencing method described above using microscale devices. Thus, sequencing reactions using double-stranded template are contemplated to take place in microfabricated reaction chambers. The present invention contemplates that suitable microscale devices comprise microdroplet transport channels, reaction regions (e.g., chambers), electrophoresis modules, and radiation detectors. In a preferred embodiment, these elements are microfabricated from silicon substrates according to those methods known in the art As a mechanical building material, silicon has well-known fabrication characteristics. The economic attraction of silicon devices is that their associated micromachining technologies are, essentially, photographic reproduction techniques. In these processes, transparent templates or masks containing opaque designs are used to photodefine objects on the surface of the silicon substrate. The patterns on the templates are generated with computer-aided design programs and can delineate structures with line-widths of less than one micron. Once a template is generated, it can be used almost indefinitely to produce identical replicate structures. Consequently, even extremely complex micromachines can be reproduced in mass quantities and at low incremental unit cost—provided that all of the components are compatible with the silicon micromachining process. While other substrates, such as glass or quartz, can use photolithographic methods to construct microfabricated analysis devices, only silicon gives the added advantage of allowing a large variety of electronic components to be fabricated within the same structure. The principal modern method for fabricating semiconductor integrated circuits is the so-called planar process. The planar process relies on the unique characteristics of silicon and comprises a complex sequence of manufacturing steps involving deposition, oxidation, photolithography, diffusion and/or ion implantation, and metallization, to fabricate a “layered” integrated circuit device in a silicon substrate (U.S. Pat. No. 5,091,328). For example, oxidation of a crystalline silicon substrate results in the formation of a layer of silicon dioxide on the substrate surface. Photolithography can then be used to selectively pattern and etch the silicon dioxide layer to expose a portion of the underlying substrate. These openings in the silicon dioxide layer allow for the introduction (“doping”) of ions (“dopant”) into defined areas of the underlying silicon. The silicon dioxide acts as a mask; that is, doping only occurs where there are openings. Careful control of the doping process and of the type of dopant allows for the creation of localized areas of different electrical resistivity in the silicon. The particular placement of acceptor ion-doped (positive free hole, “p”) regions and donor ion-doped (negative free electron, “n”) regions in large part defines the interrelated design of the transistors, resistors, capacitors and other circuit elements on the silicon wafer. Electrical interconnection and contact to the various p or n regions that make up the integrated circuit is made by a deposition: of a thin film of conductive material, usually aluminum or polysilicon, thereby finalizing the design of the integrated circuit Of course, the particular fabrication process and sequence used will depend on the desired characteristics of the device. Today, one can choose from among a wide variety of devices and circuits to implement a desired digital or analog logic feature. It is not intended that the present invention be limited by the nature of the reactions carried out in the microscale device. Reactions include, but are not limited to, sequencing according to the present invention, restriction enzyme digests, nucleic acid amplification, and gel electrophoresis. Continuous flow liquid transport has been described using a microfluidic device developed with silicon (Pfahler et al., 1990). Pumps have also been described, using external forces to create flow, based on micromachining of silicon (Van Lintel et al., 1988). Discrete droplet transport in silicon is also contemplated. III. Mapping Techniques Often it is desirable to map sequence information in very long pieces of DNA (e.g., cosmids, YACs, and within or at the ends of intact chromosomes). The landmarks that can be mapped using long-range SR reactions include (a) specific known sequences, such as those associated with a particular genes, (b) restriction sites, (c) anonymous sequences present in a library of cloned or PCR™ amplified genomic or cDNA sequences, (d) repetitive sequences such as Alu repeats, CpG islands, dinucleotide and trinucleotide repeats, SINES, LINES, and telomere repeats, (e) unusual secondary structures such as triplex DNA, quadruplex DNA, cruciform DNA, and (f) specific types of lesions, such as thymidine dimers. Present techniques are unable to map these types of features because (1) many of the features are characteristic of double-stranded DNA, and (2) mapping usually requires a nearly synchronous progression of the synthesis of new DNA. Neither of these conditions seem to be met by enzymes utilizing a single-stranded template. The present invention contemplates using the strand replacement method with a highly processive SR polymerase, such as Taq DNA polymerase, for this task. In one embodiment, SR synthesis initiates at a unique site using an excess of processive polymerase, which incorporates dATP, dGTP, dCTP, dUTP (or any other labile base) into the DNA (FIG. 8). After a controlled period of incorporation of the labile base, conditions are changed to incorporate only the stable bases dATP, dGTP, dCTP, and dTTP, with one of the stable bases being labeled, in this example labeled dTTP. The labeled base can be, for example, radioactively labeled, fluorescently labeled, or chemically labeled with biotin, among others. The uracil bases can be removed using dU glycosylase (Boehrenger Mannheim), and the sites efficiently converted to nicks by heating the DNA, treatment with base, or enzymatic cleavage with endo IV or endo V. After destruction of the dUTP-substituted DNA, the labeled DNA from the different SR reaction times (representing DNA sequences located at different distances from the initiation site) can be hybridized to a sequence of interest (e.g., telomeric sequences, dinucleotide repeats, Alu sequences, cloned or PCR™-amplified sequences, expressed sequences from a cDNA library, etc.). In the example shown schematically in FIG. 8, positive hybridization would be detected for the samples from SR reactions carried out for about 15 min, 20 min, and 30 min. If the measured rate of SR elongation was 250 nucleotides per min, those features would be mapped as being 3.75 kb, 5.0 kb, and 7.5 kb from the initiation site. To map the positions of restriction fragments the fragments would be separated by electrophoresis in agarose, transferred to a filter, and hybridized to the labeled SR products formed at different distances from the initiation sites. By hybridizing to restriction fragments transferred from an agarose gel, the order of the restriction fragments can be easily mapped. This information is very useful in large-scale sequencing projects to order the restriction fragments in cosmids and YACs. As the time of polymerization increases the polymerases can lose synchrony, which causes the width of the band of stable DNA to increase, reducing resolution. To overcome this problem agents can be introduced to reversibly halt the polymerase molecules at specific sequences. When the arrest is reversed all of the polymerases will regain their initial synchrony. For example, triplex-forming oligonucleotides can bind to recognition sequences along DNA and can arrest the progress of Klenow fragment (Hacia et al., 1994). The arrest by oligonucleotides should be reversed by mild heating or changes in pH. The technique described can also be used to map features in the DNA that terminate SR, such as unusual secondary structure, triplex formation, and specific protein binding. In this case the SR reaction would be performed using dATP, dGTP, dCTP, and dTTP and the products separated by molecular weight using electrophoresis. Sites of pausing of the polymerase would be detected by increase in product concentration or the onset of hybridization to a specific DNA probe. Dinucleotide/Trinucleotide Strings The information gained by multiple nucleotide sequencing as discussed above in Section III is also very useful for mapping the sequence information in a long DNA molecule. The map of positions of specific dinucleotides or trinucleotides serve as a fingerprint to identify overlapping parts of different DNA molecules, much the same as restriction fragment analysis and STS hybridization has been used to map overlapping DNA clones. The multiple base ladders contain more information and are more easily interpreted than the patterns of restriction fragment lengths or STS hybridization, because the ladders can be directly related to positions along the DNA molecule and can be directly related to even partial base sequence information. The multiple base ladders can also give information about the underlying structure or function of the DNA over long distances. For example, high frequencies of the dinucleotide CG can signal the presence of so-called “CpG islands” that are associated with genes. IV. Telomere Analysis The present invention overcomes many of the problems inherent in the art with regards to telomere analysis, including the lack of the ability to determine the sequence of the subtelomeric region, quantitation of the amounts of single-stranded overhangs present on chromosomes. Details of the present methods are presented below. A. Sequencing The present invention contemplates that the above-described sequencing method can be applied to a variety of double-stranded templates, including but not limited to telomeric DNA. Telomeres are special DNA structures at the ends of eukaryotic chromosomes, which are necessary for genome stability. In humans telomeres progressively shorten during somatic cell proliferation, perhaps eventually leading to chromosome instability. The rate and extent of shortening depends upon the type of tissue, and individual factors such as genetic background, age, and medical condition. In human germ line and tumor cells, telomere metabolisis is different from that of somatic cells, leading to stabilization of the length of telomeres, which is believed to be due to de novo extension of 3′ overhangs by the enzyme telomerase recombination, and perhaps other factors such as nucleases. Currently, the only parameter of telomere structure that can be measured is the length of the terminal restriction fragments. Measurements of the rate of telomere shortening cannot be performed in human tissues in less that ten years, or in selected human cultured cells in less than one month. Telomere shortening in most plants and animals cannot be measured due to excessive telomere length. The only existing test of the state of an individual's telomeres is a PCR™ assay of the in vitro telomerase activity, which is correlated with cell proliferation but not a measure whether telomeres are eroding or growing. The present invention contemplates that the sequencing method of the present invention can provide a quantitative mapping of the DNA structure at the ends of telomeres. Indeed, preliminary results from the use of the novel sequencing method reveals long 3′ overhangs at the ends of human chromosomes, suggesting a third important factor for regulating telomere length and function. The present invention contemplates that such mapping allows for the diagnosis of chromosome instabilities caused by telomerase, nucleases, recombination, and other effects important to aging and cancer. B. Two-Dimensional Techniques and Analysis of Single-Stranded Overhangs The present invention provides a variety of methods to analyze telomeres, including two-dimensional gel techniques, and hybridization and quantification of labeled oligonucleotides to the single-stranded regions of telomeres. Examples 1-5 below present details regarding these techniques. The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention. In some of the examples below fibroblasts were used. For these studies, three derivative cultures of female human fetal lung fibroblasts were purchased and grown strictly according to instructions from the NIA Aging Cell Repository (Coriell Institute for Medical Research, Camden, N.J.). Normal IMR-90 primary cells (catalog #190 P04 and #190 P10, after 4 and 10 laboratory passages) and post-crisis immortal SV40 virus-transformed IMR-90 (# AG02804C) were harvested at about 80% confluence. The IMR-90/P04 and IMR-90/P10 cells were harvested after −33 and −63 post-fetal population doubling, respectively. In some studies human umbilical vein endothelial (HUVE) cells and human leukocytes were used. HUVE cells were grown as described (Dixit et al. 1989) and harvested after 11 passages. Human leukocytes were separated from fresh blood by isotonic lysis (Birren et al., 1993). 1-2×108 cells were harvested by centrifuging 3× for 10 min at 800×g in 15 ml cold PBS followed by resuspension in PBS (−12×108/ml). A number of the examples below involve the use of nucleic acid isolated from nuclei. Nuclei were prepared using centrifugations at 4° C. as above: 1-2×108 washed cells were centrifuged once in 15 ml of nuclear buffer (60 mM KCl, 15 mM NaCl, 15 mM HEPES pH 7.4, 3 mM MgCl2, 6 μM leupeptin, 1 mM iodoacetate, 1 mM phenylmethyl sulfonyl fluoride), once in 1.5 ml nuclear buffer, twice in 15 ml nuclear buffer with 0.1% digitonin, and once in nuclear buffer with digitonin without iodoacetate; nuclei were resuspended in 1 ml of nuclear buffer without iodoacetate, diluted to 107 cells/ml with nuclear buffer without iodoacetate prepared with 50% glycerol, and frozen in liquid N2. A variety of commercially available reagents were employed. Tissue culture supplies were from Sigma (St. Louis); restriction enzymes, S1 nuclease, DNA polymerase I, T4 DNA ligase, and random labeling kit from GibcoBRL; Hinf I from BioLabs; Bal 31 nuclease, T4 DNA polymerase, dU-glycosylase, proteinase K and Agarase from Boehrenger Mannheim; Klenow fragment (exo) from Ambion; T7 gene 6 exonuclease from Amersham/USB; agarose from GibcoBRL and FMC; ZetaProbe GT membrane and PCR™ rules from BioRad; radioisotopes from Amersham. Oligonucleotides were synthesized at the University of Michigan Biomedical Research Core Facility. Oligonucleotide (CCCUAA)4 (SEQ ID NO: 1; TelC) was used as a primer for strand replacement reactions. Oligonucleotides (CCCTAA)3CCC (SEQ ID NO: 2), (UUAGGG)4 (SEQ ID NO: 3; TelG), CCCTCCAGCGGCCGG(TTAGGG)3 (SEQ ID NO: 4) and (CCCUAA)4 (SEQ ID NO: 1) were used for probe preparation. For DNA purification, a protocol for isolation of high molecular weight DNA in solution was used (Birren et al., 1993). Tissue culture and fresh blood cells were washed 3 times at 800×g in PBS, and 108 washed cells were resuspended in 0.5 ml PBS. Then 0.125 ml 20 mg/ml proteinase K solution, 1.625 ml 0.25 M EDTA, pH 8.0, and 0.25 ml 10% SDS were added in the indicated order, gently mixed and incubated at 50° C. Frozen nuclei were washed three times with nuclear wash buffer (15 mM NaCl, 15 mM Tris-HCl pH 7.5, 60 mM KCl, 3 mM MgCl2), resuspended at 300-400 μg/ml, and gently mixed with an equal volume of digestion buffer (30 mM Tris HCl pH 7.5, 100 mM EDTA pH 8, 2% SDS, 2 mg/ml proteinase K), and placed at 50° C. Equal amounts of fresh proteinase K solution were added every 12 h, and incubation continued to 36 h. DNA was extracted with buffered phenol, followed by phenol/chloroform and chloroform extractions. The clear, viscous DNA solutions were dialyzed against TE. DNA concentrations were determined by spectrophotometry (usually 100-200 μg/ml) and DNA solutions were stored at 4° C. for several months without detectable loss of integrity. For certain critical studies (e.g. for G-overhang length analysis) the DNA was digested with RNase. Telomere molarity was calculated assuming 75×106 bp per telomere (or 3.4×109 bp per haploid genome). EXAMPLE 1 Oligonucleotide Primer Dependent Strand Replacement on Double-Stranded Template Having Single-Stranded Regions Created by Nuclease Digestion Telomere DNA is difficult to sequence due to the repetitive sequences involving DNA strands that are either rich in guanine or cytosine. Single-stranded GC rich DNA forms intramolecular and intermolecular secondary structure that causes premature termination of DNA polymerization. In addition, G-rich DNA is able to form non-Watson-Crick hydrogen bonding involving G:G base pairs that are often more stable than Watson-Crick double-stranded DNA. In vitro, single-stranded G-rich telomere DNA can form a variety of non-canonical structures including G-quartets, triple helices and G:G base pairing. In this example, the primer-dependent strand replacement method of present invention was used to measure human telomere DNA. FIG. 10 shows the strand replacement approach as applied to the detection and quantitation of G-tails in human chromosomes. The oligonucleotide (CCCTAA)4 (SEQ ID NO: 5; TelCT) is hybridized under non-denaturing conditions to available G-rich tails and extended using Taq polymerase. The polymerase fills the gap between the primer and 5′-end of the C-strand and then propagates the nick in the 3′ direction. If several molecules of TelC bind to the overhang, all but the last one will be degraded during the reaction. When electrophoresed on a denaturing alkaline agarose gel and probed with both the G-rich and C-rich telomeric sequences, the reaction products should appear as three bands: Cs corresponds to the newly-synthesized extension products; Ct corresponds to the trimmed original C-rich strands; and Co corresponds to the original G-rich strands and untrimmed C-rich strands from any telomeric ends without overhangs or with such short overhangs that they cannot bind the primer. In this example, the reaction was carried out on a model linear telomere construct. The construct with 520-700 bp of double-stranded human telomere DNA and 100-200 b of G-rich overhang was constructed from plasmid Sty11. Sty 11 was cut with ClaI which leaves 10 bp of polylinker DNA at the end of a 800 bp telomere tract. The linearized plasmid was digested with Bal 31 for 30 seconds at 30° C. using 2 units of enzyme with 10 μg DNA in 100 μl of 600 mM NaCl, 12.5 mM CaCl2, 12.5 mM MgCl2, 20 mM Tris-HCl pH 8.0, and 1 mM EDTA. The DNA was extracted and resuspended in TE. EcoR I restriction and electrophoretic analysis determined that the Bal 31 had trimmed about 60 bp from each end, sufficient to expose the telomeric repeat. To produce a 3′ overhang 5 μg of linearized or linearized/Bal 31 treated DNA was incubated with 100 units of T7 gene 6 exonuclease in 50 μl of 40 mM Tris-HCl pH 7.5, 20 mM MgCl2, 50 mM NaCl at 20° C. for different times, extracted, and resuspended in TE. The average G-tail length and length distribution were determined by digestion with EcoRI, electrophoresis in 1.5% agarose/40 mM NaOH and analysis of the length of the C-strand. It was determined that, following the above treatment, one end of the construct had a 650 bp terminal tract of double-stranded telomeric DNA with a 100 b G-tail. The strand replacement reaction was performed using Taq DNA polymerase. The optimized reaction was performed in 50 μl of the standard Taq polymerase buffer [composed of 20 mM Tris-HCl pH 8.3, 50 mM KCl, and 2 mM MgCl2 containing 50 μM dNTPs, 5-10 nM TelC primer, 0.1-1 fool of DNA telomere ends (5-50 μg of human DNA or 0.1-1 ng of Sty11 telomere construct) and 2 units of Taq polymerase] and was carried out at 55° C. To insure the hybridization of the TelC primers to all single stranded telomere ends, the ingredients of the reaction (except Taq polymerase) were placed into 0.5 ml thin-wall PCR™ tubes, mixed, covered with mineral oil, and incubated at 45° C. for 1 h in a DNA Thermal Cycler 480 (Perkin-Elmer, Cetus). The temperature was increased to 55° C. for 5 min, and Taq DNA polymerase was added. Aliquots were removed at the desired times and quenched on ice with 10 mM EDTA. All DNA samples were incubated with dU-glycosylase (1 μl enzyme 50 μl reaction) at 37° C. for 1-2 h, ethanol precipitated, washed and dried. The dU-glycosylase promoted primer degradation during alkaline electrophoresis, greatly reducing the background on Southern blots. The results of the strand replacement reaction using the model construct show that the size of the Cs strand increased at the same rate as the size of the Ct strand decreased, ruling out strand displacement (Henderson et al., 1988). In the presence of four dNTPs the nick-translation reaction proceeded to the opposite end of the linear construct. In the presence of only dATP, dTTP and dCTP the reaction proceeded only to the end of the telomeric tract, producing a discrete 750 b C-rich strand. Substitution of dTTP with dUTP and incubation of the reaction products with dU-glycosylase followed by alkaline treatment led to complete elimination of the Cs strand. After long reactions the Ct strand hybridized with the random-primed plasmid, but not (TTAGGG)4 (TelG). A 100 b overhang is long enough to initiate multiple strand replacement reactions, however the terminal Cs strand should destroy and replace internally-located primers and products. Thus the Cs product made without dGTP had the same size as the C-rich fragment without T7 gene 6 treatment. No strand replacement products were found (a) without primers, (b) with TelG primers, (c) with non-telomeric primers, or (d) on constructs without G-tails. In sum, the strand replacement signal is dependent upon the presence of the TelC primer showing that products are not formed from internal nicks or gaps. In the model system, the strand replacement reaction with (TTAGGG) overhangs is specific for a primer containing the (CCCTAA) repeat, and blunt-ended telomeric ends are not detected. EXAMPLE 2 Oligonucleotide Primer Dependent Strand Replacement on Double-Stranded Template Having Naturally Occurring Single-Stranded Regions In this example, the strand replacement method was used to detect naturally occurring single-stranded regions of telomeric DNA. Specifically, the strand replacement method was used to detect G-tails in IMR-90 normal primary human fibroblasts. These telomeres are from fetal lungs and therefore have very long telomeres (approximately 12 kb). High molecular weight (>100 kb) IMR-90 DNA was subjected to the strand replacement reaction and the products were analyzed by I-D alkaline gel electrophoresis. Specifically, high molecular weight primary IMR-90 cell DNA was subjected to strand replacement for 5, 10 and 15 min and electrophoresed. Alkaline electrophoresis was performed in 0.8-1% agarose with 40 mM NaOH. The gel was prepared with 50 mM NaCl, and 1 mM EDTA, solidified, and soaked in 2 liters of alkaline electrophoretic buffer (40 mM NaOH and 1 mM EDTA). Dried DNA samples were dissolved in alkaline loading buffer (2.5% Ficoll, 50 mM NaOH, 1 mM EDTA, and 0.025% Bromocreosol green), loaded and run at 1 V/cm (250-300 mA) for 12-16 hours at room temperature with buffer circulation. The gel was neutralized by soaking in 1×TBE buffer for 1 h and vacuum blotted onto the nylon membrane. The material transferred to the membrane was thereafter probed with radioactive TelG. Reactions were conducted with four dNTPs with TelC; with four dNTPs without TelC primer; and with three dNTPs with TelC primer. The time course of the reactions with TelC primer and four dNTPs showed that the rate of Cs synthesis was approximately 250 b/min. DNA fragments of similar size were synthesized when dGTP was omitted, indicating the telomeric origin of the products and the absence of guanine blocks in the terminal 4 kb of the human telomere C-strands. Incorporation of dUTP followed by incubation with dU-glycosylase and alkaline treatment caused loss of the Cs products. Reactions with equal numbers of human and rat telomeres gave nearly identical amounts of Cs product, even though the rat telomeres are 10 times longer (Makarov et al., 1993), consistent with priming only at termini. These results demonstrate that the strand replacement synthesis with Taq DNA polymerase can proceed in a controlled fashion at least 4 kb along double-stranded native DNA. The results are interpreted as synthesis of new DNA strands beginning at the telomere termini. Several alternative explanations can be ruled out. First, no products were generated in the absence of the TelC primer, showing that there are not significant numbers of gaps or nicks in the C-rich strands. Discontinuities in the G-rich strands are ruled out by the fact that the products were of high molecular weight. To further confirm the nature of the reaction, alkaline agarose electrophoresis analysis and detection by filter hybridization was investigated when the naturally occurring G-tails were removed. To remove G-tails 10 mg of IMR-90 DNA was incubated with 300 units/ml S1 nuclease for 15 min at 37° C. in 50 mM NaAc pH 4.5, 1 mM ZnCl2, and 200 mM NaCl, or with 20 units/ml Bal 31 nuclease for 5 min at 30° C. in Bal 31 buffer. For the same purpose, 2 ng of plasmid construct, 10 mg of IMR-90 DNA, or a mixture of the two was incubated with 10 units of T4 DNA polymerase for 10 min at 37° C. in 50 mM Tris-HCl pH 8.8, 15 mM (NH4)2SO4, 7 mM MgCl2, 0.1 mM EDTA, 10 mM 2-mercaptoethanol, and 100 μg/ml bovine serum albumin DNA was extracted and resuspended in buffer. T4 DNA polymerase trimming reduced the amount of product by more than 10-fold in reactions with (a) the plasmid construct, (b) IMR-90 DNA, or (c) a mixture of IMR-90 DNA and construct (“+” indicates treatment and “−” indicates no treatment). Treatment of IMR-90 DNA with S1 nuclease or with Bal 31 nuclease completely eliminated the reaction. These data strongly indicate that the strand replacement synthesis requires a 3′ G-rich terminus. G-tails do not seem to be generated or lost during DNA isolation. Concentrations of proteinase K and EDTA were increased during DNA isolation, without effect on the signal. The isolation protocols were changed in an attempt to test the sensitivity of the assay to formation of unusual secondary structure (e.g., exposure of a G-tail due to strand slippage, or concealment of a G-tail due to formation of G-quartets). Cells and nuclei were incubated with the digestion buffer at 45, 37, and 25° C. to reduce the chance of thermally-induced conformational transition. K+ and Na+ ions were excluded and replaced by Li+ or Tris+ in all isolation steps to reduce the possibility of G-quartet formation. Extractions with phenol and chloroform were replaced by dialysis to avoid organic solvents and precipitation. None of the protocols tested had qualitative or quantitative effects on the strand replacement reaction or on non-denaturing hybridization (see below). Thus the assays for G-tails are robust and not sensitive to changes in treatment EXAMPLE 3 Strand Replacement Synthesis to Measure the Abundance and Length of Telomere 3′ Overhangs In this example, the strand replacement method of the present invention was combined with non-denaturing hybridization to determine the average lengths of 3′ tails in humans. Hinf I digested human DNA, plasmid constructs with 100 b, 170b and 220 b overhangs, or a nearly equimolar (in terms of telomere ends) mixture of human and plasmid DNA were hybridized at 50° C. with 1 nM32P-TelC in 20-30 μl of hybridization buffer (50 mM NaCl, 1 mM EDTA and 50 mM Tris-HCl, pH 8.0) for 12-16 h. Some of the samples were subjected to strand replacement (100 mM dNTP, 5 units Taq DNA polymerase; 10 min at 55 ° C.), then all samples were electrophoresed on a 1% agarose/TAE gel, electroblotted onto a nylon membrane for 16 h and quantitated. The absolute telomere molarity of the IMR90/P04 DNA solution was approximated by spectrophotometry. The molarities of plasmid constructs and telomeres from different human cells were determined by CCD analysis of fluorescence of ethidium bromide stained gels; the signal intensities of plasmids and telomeres were normalized to the signal intensities of a DNA Mass Ladder (GIBCO BRL) and IMR90/P04 DNA, respectively. 32P-labeled TelC was hybridized under native conditions to the same numbers of human telomeres and control DNA constructs with known lengths of 3′ overhangs. The telomeres and constructs were electrophoresed to remove unbound TelC, and the average length of G-tails determined by two independent methods. An autoradiogram of DNA samples from blood, HUVE, and primary IMR-90 cells showed broad bands of radioactivity at 10-12 kb, coinciding with the telomere terminal restriction fragments found by denaturing hybridization, except for the absence of the sharp bands due to the interstitial (TTAGGG)n tracts. Treatment of the human and construct DNA with S1, mung bean, or Bal 31 nucleases, or with T4 DNA polymerase led to elimination or significant reduction (after T4 polymerase) of the non-denaturing hybridization signal without affecting the size or intensity of the denaturing hybridization signal. The strength of the TelC hybridization was the same for DNA isolated from both cells and nuclei, prepared by phenol extraction or by only proteinase K/SDS digestion and dialysis. Non-denaturing hybridization with TelG was 20-30 times lower than with TelC for both human and plasmid DNA, consistent with the absence of single-stranded (CCCTAA)n and a very low level of G:G hydrogen bonding. DNA constructs with (CCCTAA)n overhangs hybridized strongly to TelG and showed no binding to TelC. The low efficiency of hybridization of telomeres with TelG is strong evidence that the G-tails are covalent extensions (i.e., different lengths of the C- and G-rich strands) rather than conformational extensions (i.e., slippage of the C- and G-rich strands producing G-overhangs and C-loops). TelC hybridizes to the constructs with weight-average G-tail lengths of 0, 100, 170, and 220 b showed that the TelC hybridization signals were nearly proportional to the average lengths of the G-overhangs (FIG. 11). Thus, quantitation of the amount of TELC hybridization under these non-denaturing conditions can be used to determine the abundance of single stranded telomere DNA at the ends of chromosomes. The lengths of the G-tails were first measured by comparing the hybridization signal of TelC to genomic DNA with that of TelC to DNA constructs having G-tails of known lengths. Using non-denaturing hybridization of Hinf I-digested IMR-90/P04 DNA mixed with an equimolar amount of telomeric ends from the construct with a 100 b G-tail, the hybridization signal of the human DNA was 1.25 times greater than that of the plasmid control. To accurately determine the relative molarity of the human and plasmid overhangs, the same samples were subjected to a 10 min strand replacement reaction, which should destroy all but the terminal TelC. The relative hybridization signals for the human and plasmid DNA were easily measured, because of the low background in the plasmid-only control. Assuming that the same number of labeled oligonucleotides remained bound to the ends of the human and plasmid DNA, the molarity of the plasmid ends was 11% greater than that of the human DNA. This similarity in the estimated molarities of the telomere ends and G-overhangs is consistent with the inventors' finding that most or all telomeres have G-tails. Thus, the non-denaturing hybridization signal for the human DNA was 1.39 times greater than to the same number of moles of plasmid with 100 b overhang. Using the experimental dependence of hybridization upon G-tail length, the inventors calculate that the IMR-90/P04 overhangs were 154 b long (FIG. 11). In a separate study Tel C was hybridized under non-denaturing conditions to IMR-90/P04, IMR-90/P10, immortal IMR-90, leukocyte, and HUVE cells. The relative amounts of DNA were determined from ethidium bromide fluorescence, and the relative amounts of hybridization by autoradiography. The lengths of the G-tails were between 130 and 210 b long, assuming that the IMR-90/P04 overhangs were 154 b long (Table 3). The lengths of the IMR90-P04 G-tails were also estimated from the fraction of hybridized TelC that is removed by the strand replacement reaction. SR decreased the radioactivity of the human and plasmid DNA by factors of 6.2 and 4.5, respectively, leading one to conclude that the human and plasmid ends bound an average of 6.2 and 4.5 oligonucleotides. Assuming that Tel C saturated the G-tails, the size of the overhangs can be estimated to be 149 in human and 108 bases in the construct The consistency of these numbers with the earlier results increases the confidence in the estimates of the length and abundance of telomere G-tails. TABLE 3 Measured Fractions And Lengths Of G-rich Tails In Human and Control DNA DNA Control IMR-90/ IMR-90/ IMR-90 Sample Plasmid P04 P10 Immortal HUVE Leukocyte Fraction 0.85 0.86 ± 0.03 0.89 ± 0.03 0.88 ± 0.03 0.87 ± 0.03 0.82 ± 0.05 of (N = 1) (N = 17) (N = 4) (N = 3) (N = 3) (N = 3) strands with detectable G-tailsa Average 100c 154 (149)d 210 130 150 200 length (108)d of G-tail (bases)b EXAMPLE 4 Measuring Telomere Defects The current method of studying telomere shortening is inaccurate in determining the average length of telomeres, unable to determine the distribution of telomere lengths (particularly the lengths of the shortest telomeres) and is insensitive to defects in the sequences of the telomeric DNA. The present invention provides methods to overcome these limitations. These methods can measure the potential that individuals (particularly those with age-related conditions such as cancer, AIDS, Alzheimer's, atherosclerosis, and the progerias) will experience a “telomere crisis” due to telomere shortening, and in predicting or evaluating the efficacy of anti-telomerase therapy or other therapies designed to control telomere function in the treatment of those diseases. While the successful use of the methods of the present invention does not depend on a precise understanding of the mechanism of telomere shorting, the present invention contemplates that the functional parts of telomeres (FIG. 12) include regions C and D only, and that exposure of regions A or B to the termini of one or more chromosomes as the result of telomere shortening in normal or precancerous human cells will result in dysfunction of the telomeres, specifically arrest of growth and/or chromosome instability. Evidence that the sequences in region B are not functional comes from studies showing that cells cannot survive with new telomeres made with telomere-like sequences such as (TTGGGG)n and that cell-free extracts are not able to prevent such sequences from non-covalently attaching to each other. Such non-covalent attachments in human cells might lead to the non-clonal telomere associations that characterize the cells of elderly humans and certain human diseases such as ATM and giant cell osteogenic sarcoma It is critical to directly measure the average and the shortest lengths of region C in human cells and to determine the DNA sequences in region B in order to definitively test the telomere hypothesis of aging and cancer. If the proposed mechanism is correct, such measurements could find clinical applications to test individual humans to accurately measure the rate of telomere shortening or lengthening, predicting future chromosome instabilities, predicting the future behavior of tumor cells or lymphocytes in HIV positive or Alzheimer's individuals, and predicting the efficacy of telomere-modifying therapies. In one embodiment, the steps of the method of the present invention for mapping sequence defects in telomeres comprises: 1) initiation of the synthesis of a new DNA molecule beginning at or near the chromosome terminus, 2) elongation of the synthesis of a new DNA molecule with the repetitive sequence (CCCTAA)n, which is characteristic of a functional vertebrate telomere, and 3) termination of synthesis at an unexpected base, specifically at the first point at which a guanosine is present in the “C-rich strand” within the unique sequence adjacent to the telomeres near the right-most end of fragment A, or within region B (see the arrow in FIG. 12). This mapping reaction has the same basic characteristics of the sequencing reactions, described above, except that termination is achieved when the polymerase is directed to incorporate a guanine into the growing strand, and the analysis is performed by low resolution electrophoresis of high molecular weight DNA product on an agarose gel, as opposed to sequencing which employs single base-resolved electrophoresis on a polyacrylamide gel. More specifically, when only three natural nucleotides is provided to the polymerase, specifically dATP, dTTP, and dCTP, elongation will proceed unimpeded, copying all of the G-rich strand of the telomeric sequence, (TTAGGG)n. Termination will occur however, the first time that a guanosine appears in the C-rich strand, which will happen within a few bases of unique-sequence DNA, in region A, or perhaps within the telomere-like sequences that might exist in region B (FIG. 12). In other words, elongation will stop only when a specific type of defect occurs in the sequence. When such a cytosine is present the polymerase will be unable to add a new base due to the fact that dGTP is not present in the reaction, or an incorrect base will be incorporated. To optimize the reaction with Taq or to use other enzymes, with proofreading activities, a certain concentration of ddGTP (to be optimized) can be added to the reaction mixture to insure a full stop of elongation. The length of the synthesized DNA is measured in order to determine how far from the chromosome terminus the termination event has occurred. The advantage of this general technique is that it can determine the total length of regions C+D+(a fraction of region B), without being sensitive to the chromosome-specific variations in the length of regions A and B. The reaction products are electrophoresed on a denaturing alkaline agarose gel to separate them according to molecular weight and detected by standard methods. If a label is incorporated only into the oligonucleotide primer, into the initial few bases of the strand replacement reaction, or into ddGTP, the distribution of number of telomeres of different molecular weights can be determined. This provides a relatively easy means to measure the lengths and abundance of telomeres with very short C+D regions, as might be found in geriatric individuals or in cancer cells. EXAMPLE 5 Mapping of Telomere-Like Sequences in Region B When all 4 dNTPs are present during a DNA polymerase replacement synthesis initiated from the end of chromosomes (as described above) the distance of the polymerase from the end will depend upon reaction time. As longer products are made, they will have 3′ ends in regions D, C, B, and then A. There are many ways to use the strand replacement method of the present invention to determine the properties of the telomeric sequences specific distances from the terminus. For example, the strand replacement reaction can be initiated with a variable time of incorporation of dUTP, dGTP, dCTP, and dATP, followed by removal of the dUTP and replacement with dTTP and continuation of the strand replacement reaction for a fixed time. The products are schematically shown in FIG. 13. Subsequently, the uridine bases can be destroyed using deoxyribouridine glycosylase and heat, leaving only the DNA bases added at the end of the reaction, which are different distances from the termini of the chromosomes. This DNA can be hybridized to probes containing (TTAGGG)n and washed at different stringencies to detect whether the DNA has the (TTAGGG)n sequence, or a variant sequence. Alternatively oligonucleotide probes with different sequences can be hybridized to the SR products and washed under stringent conditions to search for specific variant sequences. In principle the products of strand replacement reactions for different times can be combined in the same sample, electrophoresed under denaturing conditions to separate the products according to molecular weight (i.e., with 3′ ends located different distances from the chromosome termini), the DNA blotted to filter, the dUTP sites destroyed, and the remaining DNA hybridized to different probes to determine the nature of the DNA sequences different distances from the end. In principle, even single-base variations in the sequences of the glycosylase-resistant fragments could be detected by hybridizing the SR products to labeled telomere sequence oligonucleotides such as (TTAGGG)4 (SEQ ID NO: 6), followed by cleavage of the oligonucleotide at any mismatched sites using any one of a number of single-base mutation detection reagents, such as E. coli endo IV. The cleaved oligonucleotides can be detected by gel electrophoresis or by loss of energy transfer between fluorescent groups at the ends of the oligonucleotides. This type of reaction lends itself to automation. In one embodiment, the strand replacement reaction is performed from the beginning in the presence of the 4 normal dNTPs. All that is required is the separation of the SR products from the genomic DNA. As in the previous paragraph, the products of many times of strand replacement can be combined into one sample, which can be separated by molecular weight, hybridized to the oligonucleotide, transferred to a filter, washed to remove unbound oligonucleotides, and cleaved for detection of mismatched bases located at different distances from the ends of the telomeres. Alternatively, the sequence purity at a specific distance from the end can be mapped by detecting variations from the exact 6 base repeat of thymine along the SR product strand. In this assay, after a controlled time of strand replacement in the presence of dCTP, dATP, dGTP, and a controlled ratio of dUTP to dTTP, the nucleotides are removed and replaced with dCTP, dATP, dGTP, and a controlled ratio of dTTP and radioactively- or fluorescently-labeled ddTTP. All SR products would then terminate with a labeled 3′ dideoxy thymidine. Degradation of the DNA using deoxyribouridine glycosylase and heat would then terminate the other ends of the products at positions containing thymidine. For reactions terminating in regions of the chromosomes with pure (TTAGGG)n tracts the labeled DNA fragments would form a 6 base ladder on a sequencing gel. For regions with sequence variations that did not retain the perfect 6 base repeat of thymidine, the sequencing gels would exhibit loss of the 6 base ladder. The best method to detect sequence variations within the telomeres will depend upon the nature of the variations found, whether they involve occasional guanines in the 5′ strands, non-guanine substitutions for the normal repeat, or variations in the number of bases within some of the repeats. The nature of the actual sequence defects in human telomeres has not been studied in any detail. The methods of mapping of the present invention can be applied to determining the types of sequence defects present within telomeres in normal and abnormal human cells. For example, the DNA synthesized different distances from the ends of telomeres can be cloned and sequenced by standard methods to discover the actual sequence variants present. EXAMPLE 6 Sequencing Double-Stranded DNA Using ddNTP-Terminated Strand Replacement Reaction A strand replacement sequencing reaction was performed on a linear, double-stranded plasmid template using Taq polymerase, 32P radioactively labels, and polyacrylamide electrophoresis. The study involved a) DNA preparation, b) strand replacement, c) and gel electrophoresis. A) DNA Preparation 40 μg of plasmid pUC19 (New England Biolabs) was digested 2.5 h at 37° C. with 200 units of Bam H1 (Boehringer Mannheim Biochemicals, “BMB”) in 200 μl of 0.1×BMB “restriction buffer B.” The fraction of linearized plasmid was checked by electrophoresing 2 μl of the restricted DNA solution on a 1% agarose gel. The termini of the restricted plasmid were dephosphorylated in a 30 min reaction at 37° C. with 188 μl of the restricted DNA (39.5 μg), 23 μl of 10× alkaline phosphatase buffer (BMB), 5 μl of shrimp alkaline phosphatase (BMB), and 2 μl H2O. The solution was then heated to 70° C. for 15 min to inactivate the alkaline phosphatase. The DNA was precipitated by adding 5 μl glycogen (10 μg/μl), 23 μl 3 M sodium acetate (pH 5.2), and 2.5 volumes 100% ethanol, and stored overnight at −70 ° C. The DNA was pelleted 15 min at 13,000 g and the pellet washed twice with cold 70% ethanol. The DNA was resuspended in 70 μl H2O. The DNA in 67.8 μl was mixed with 7.2 μl of double-stranded adaptor oligonucleotide (25 pmol/μl), 20 μl of 5× ligation buffer (BMB), and 5 μl (1 unit/μl) T4 DNA ligase (BMB). The ligation reaction took place overnight at 14-16° C. The ligase was inactivated at 70° C. for 15 min. The ligation substrates and products had the following structure: Bam HI - Adaptor Before ligation: pUC19 5′---GTACCCGGG-OH P-GATCGACGAUACCGUGGACCUCGTTTTT 3′OH 3′---CATGGGCCCCTAG-OH OH-TGCTATGGCACCTGGAGCAAAA 5′OH After ligation: 5′------GTACCCGGGGATCGACGAUACCGUGGACCUCGTTTTT 3′ OH 3′------CATGGGCCCCTAG TGCTATGGCACCTGGAGCAAAA 5′ OH *1 nucleotide gap After ligation, 98 μl (39 μg) pUC19 was digested for 2.5 h at 37° C. with 16 μl (10 units/μl) Pst I, 30 μl buffer H (buffer H from BMB), and 156 μl H2O, in order to remove the adaptor oligonucleotide from one end of the molecule. This insured that the strand replacement reaction would initiate at one end of the template. Aliquots of the DNA were analyzed to insure that ligation and restriction had been complete. The 2.7 kb ligated BamH I/Pst I pUC19 fragment was purified on 1% low melting agarose. The gel band (1.6 ml) was excised from the gel and incubated for 10 min at 65° C., and then incubated with 2 h at 45° C. with 10 μl agarase (1 unit/μl), 66 μl 25× agarase buffer (BMB). The sample was mixed with 166 μl of 3 M sodium acetate (pH5.2), mixed, and spin at 13,000 g for 10 min. The supernatant was spun a second time for 10 min and the DNA extracted with phenol/chloroform once and chloroform twice. DNA was precipitated as above and suspended in 40 μl H2O. Final yield was 15 μg DNA. B) Strand Replacement Two protocols were used for the SR sequencing reactions. The solutions and reagents for the sequencing reactions were as follows. The Buffers were: Buffer A: 100 mM Tris HCl, pH 8.0, 100 mM MgCl2; and Buffer B: 500 mM Tris HCl, pH 8.9, 100 mM KCl, 25 mM MgCl2. The Labeling Mix was 10 μM dGTP, 5 μM dCTP, 5 μM dTTP, 10 μM Tris HCl, pH 8.0. The Polymerization/Termination Mixes were as follows: G-terminating mix: 30 μM dNTP; 0.25 mM ddGTP; 0.37 mM MgCl2; A-terminating mix: 30 μM dNTP; 1.0 mM ddATP; 1.12 MM MgCl2; T-terminating mix: 30 μM dNTP; 1.5 mM ddTTP; 1.62 mM MgCl2; and C-terminating mix: 30 μM dNTP; 0.5 mM ddCTP; 0.62 mM MgCl2; where 30 μM dNTP represents 30 μM of each of dGTP, dCTP, dATP and dTTP. The Labeling Solution was 2 μl 32P-dATP [3000 Ci/mmol (3.3 μM), Amersham], 2 μl 10 μM dATP, 1 μl 50 mM Tris HCl, pH 8.0. The Taq DNA Polymerase Dilution Buffer was 10 mM Tris HCl, pH 8.3, 50 mM KCl, 0.5% Tween 20, 0.5% Nonidet P40. The Stop/Loading Solution was 95% formamide, 20 mM EDTA, 0.05% Bromphenol Blue, 0.05% Xylene Cyanol. The Taq DNA Polymerase was AmpliTaq, (Cat. # N801-0060, Perkin Elmer), and the nucleotides were GeneAmp dNTPs, 10 mM, (Cat. # N808-0007, Perkin Elmer) and ddNTPs (Cat. #775 304, Boehringer Mannheim). The first protocol details sequencing using [α-32P] dATP for the incorporation of label. To insure that all the strands were bound to primer, the DNA was hybridized under non-denaturing conditions to the primer oligonucleotide 5′-AAAACGAGGTCCACGGTATCGT-3′ (SEQ ID NO: 7). To do this 0.2 pmol pUC19 DNA (0.17 pmol/μl or 0.3 μg/μl) was added to 0.4 pmol primer (0.1 pmol/μl), 1 μl Buffer A or 2 μl of Buffer B, and H2O to make a total of 10 μl. The mixture was heated at 65° C. for 5 min, then at 37° C. for 30 min. To one tube was added 2 μl of the labeling mix, 2 μl of the labeling solution, 1 μl Taq DNA polymerase (diluted 2 times with Taq dilution buffer), and 5 μl H2O. The mixture was incubated at 37° C. 5 μ aliquots were taken after 1 min, 2 min, 5 min, and 10 min of the labeling reaction. Then 2 μl of the “A”-terminating mix were added to 4 μl of labeled DNA (after 1, 2, 5 and 10 min reaction) in a 0.5 ml tube, covered with mineral oil and incubated at 55° C. for 10 min. The reaction was stopped by adding 4 μl of the Stop/Loading solution. Samples were heated at 95° C. for 3 min, cooled at 4° C. and loaded on the sequencing gel. The second protocol details sequencing using a kinase 32P-labeled primer, end labeled using [γ-32P] ATP. Prior to initiating strand replacement, a mix was made comprising 3 μl pUC19 DNA (0.5 pmol), 2 μl of 32P-kinase labeled primer (1 pmol), 1 μl Buffer A or 3 μl Buffer B, 9 μl 10 mM Tris HCl, pH 8.0 (if Buffer A) or 11 μl H2O (if Buffer B). The mixture was heated at 65° C. for 5 min, and then at 37° C. for 30 min. To initiate strand replacement, 1 μl of Taq DNA polymerase (diluted 2 times with the dilution buffer) was added to the mixture at room temperature to create a second mixture. Thereafter, the following solution were added to 4 μl of this second mixture: 2 μl of the “G-terminating mix” (“G”-tube); 2 μl of the “A-terminating mix” (“A”-tube); 2 μl of the “T-terminating mix” (“T”-tube); 2 μl of the “C-terminating mix” (“C”-tube); and 2 μl of the 30 mM dNTP mix (“dNTP”-tube). The “G”, “A”, “T”, “C” and “dNTP”-tubes were incubated at 55° C. for 10 min. The reaction was stopped by adding 4 μl of the Stop/Loading solution, and the reaction was heated at 95° C. for 3 min, cooled at 4° C., and loaded on sequencing gel. 5 C) Gel Electrophoresis A standard denaturing 6% polyacrylamide sequencing gel was run under standard conditions (Ausubel et al., 1991). The 32P-labeled SR products were detected by autoradiography on film, exposed ˜8 h at room temperature. FIG. 14A and FIG. 14B are images of the autoradiograms. FIG. 14B represents the reactions performed in buffer B. Lanes 1-4 represent DNA labeled with 32p dATP for 1 min, 2 min, 5 min, and 10 min, respectively. Each of these reactions incorporated ddATP. The bands are at the positions expected for adenines in the pUC19 sequence. Very little background is found between bands and the bands have uniform intensity. At this ratio of ddATP to dATP, the strand replacement reaction continued on to high molecular weight, beyond the resolution of the gel. Lanes 5-8 correspond to DNA labeled using kinase-labeled primer from different termination tubes, “G-tube”, “A-tube”, “T-tube”, and “C-tube”, respectively. Each of these lanes had bands corresponding to ddNTP termination at the cognate base position in the double-stranded template DNA. The ddNTP mixes have not been optimized to give the same radioactivity in each lane, however all lanes show termination at the ddNTP sites without detectable background between lanes due to premature termination of the SR sequencing reaction. Band intensities are very uniform from site to site within lanes, except where bands overlap due to homopolymeric tracts. Lane 9 corresponds to DNA labeled using kinase-labeled primer in the reaction of the “dNTP tube.” This reaction shows no termination of the strand replacement reaction at low molecular weights, illustrating lack of detectable premature termination of the product. FIG. 14A represents the same reactions seen in the left panel, with the exception that the reactions were run in buffer A. Under these conditions there are detectable amounts of premature termination, even in lane 9, which represented the “dNTP tube.” Thus the strand replacement synthesis from a double-stranded template can be used to sequence DNA. EXAMPLE 7 “Base Walking” Sequencing Reactions Multiple base sequencing involves specifically labeling DNA molecules with 3′ ends terminated at specific combinations of two or more bases. This process involves one or more cycles of “base walking” with a specific series of bases followed by a “termination” reaction with a selected labeled nucleotide. For example, to label strands terminated with the dinucleotide AT, there would be a single A-walk reaction followed by a T-termination reaction. The two critical steps of an N-walk (where N is one of the four base types) are a “dd(-N)-blocking” (dideoxy minus N-blocking) reaction, followed by removal of unincorporated nucleotides, and then followed by an “N-extension” reaction. The dd(-N)-blocking reaction consists of reacting the 3′ OH ends with polymerase and all three of the dideoxyribonucleotide bases except the specified N base. The N-extension reaction consists of reacting the 3′ OH ends with the specified N base. Single N-extension reactions with different dNTPs and blocking reactions with mixtures of three different ddNTPs were performed on model oligonucleotide templates DNA using ThermoSequenase™ (Amersham), 32P radioactively labeled primers, and polyacrylamide electrophoresis. The single-base extension reactions were performed using phosphorothiolated bases, which are incorporated with the same efficiency and fidelity as normal nucleotides by DNA polymerase. Therefore, the same results are obtained if normal nucleotide bases are used. The experiments involved reagent preparation, N-extension reactions, dd(-N) blocking reactions, and gel electrophoretic analysis of the products. The results directly show that the blocking and extension reactions are highly specific and efficient The high specificity of the blocking reactions show that termination reactions are also specific and efficient. Thus the results show that the basic steps of multiple-base sequencing have been achieved. A. Reagent Preparation The oligonucleotides used for preparation of the model constructs had the following structure: Oligo-template, 5′-CAGGATGTGACCCTCCAGCACATAGGTCTACG-3′ (SEQ ID NO: 8); Primer A, 3′-GGTCGTGTATCCAGATGCCAG-5′ (SEQ ID NO: 9); Primer G, 3′-GAGGTCGTGTATCCAGATGCCAG-5 (SEQ ID NO: 10); Primer T, 3′-GGGAGGTCGTGTATCCAGATGCCAG-5′ (SEQ ID NO: 11); Primer C, 3′-ACTGGGAGGTCGTGTATCCAGATGCCAG-5′ (SEQ ID NO: 12). 10 pmol of each oligonucleotide primer A, T, G and C were separately 5′-end labeled for 10 min at 37° C. using 10U T4 kinase (BRL), 10 μCi γ-ATP (Amersham) and 1×T4 kinase buffer (BRL) in 25 μl volume. Reaction was terminated by adding 0.5 μl of 0.5 M EDTA and 74.5 μl H2O and heating for 10 min at 90° C. (final concentration-100 nM). 10 μl (1 pmol) of each 32P-labeled primer A, T, G, and C were mixed with 40 μl of 10 μM oligo-template, 10 μl of GeneAmp 10×PCR buffer II (500 mM KCl, 100 mM Tris-HCl, pH 8.3; Perkin Elmer), 6 μl 25 mM MgCl2, and 4 μl H2O. The mixture was heated to 85° C. and then annealed during slow overnight cooling to room temperature. The mixed construct was stored at −20° C. The buffers used were as follows: 1× Walk buffer (50 mM KCl, 10 mM Tris-HCl, pH 8.3, 1.5 mM MgCl2); TE buffer (10 mM Tris-HCl, pH 7.5, 0.1 mM EDTA); “Stop” solution (2.25 M sodium acetate, 63 mM EDTA, 2.5 mg/ml glycogen (Boehringer Mannheim Biochemicals, “BMB”)). The dNTP mixes used were: “10 μM α-S-dATP”: 10 μM α-S-dATP in 1× Walk buffer, “10 μM α-S-dTTP”: 10 μM α-S-dTTP in 1× Walk buffer, “10 μM α-S-dGTP”: 10 μM α-S-dGTP in 1× Walk buffer, and “1 μM α-S-dCTP”: 1 μM α-S-dCTP in 1× Walk buffer. The Balanced dd(-N) mixes were as follows: Balanced stock “dd(-A) mix”: 400 μM ddTTP, 400 μM ddGTP, 50 μM ddCTP in 1× Walk buffer, Balanced stock “dd(-T) mix”: 1000 μM ddATP, 400 μM ddGTP, 50 μM ddCTP in 1× Walk buffer, Balanced stock “dd(-G) mix”: 1000 μM ddATP, 400 μM ddTTP, 50 μM ddCTP in 1× Walk buffer, and Balanced stock “dd(-C) mix”: 1000 μM ddATP, 400 μM ddTTP, 400 μM ddGTP in 1× Walk buffer. To prepare “1/10 dd(-N)”, “1/100 dd(-N)”, “1/1000 dd(-N)”, and “1/10000 dd (-N)” mixes balanced stock dd(-N) solutions were diluted 1:10, 1:100, 1:1000, and 1:10,000 with 1× Walk buffer. The Unbalanced dd(-N) mixes were as follows: Unbalanced “dd(-A) mix”: 200 nM ddTTP, 200 nM ddGTP, 20 nM ddCTP in 1× Walk buffer, Unbalanced “dd(-T) mix”: 200 nM ddATP, 200 nM ddGTP, 20 nM ddCTP in 1× Walk buffer, Unbalanced “dd(-G) mix”: 200 nM ddATP, 200 nM ddTTP, 20 nM ddCTP in 1× Walk buffer, and Unbalanced “dd(-C) mix”: 200 nM ddATP, 200 nM ddTTP, 200 nM ddGTP in 1× Walk buffer. B. N-Extension Reactions Single-base polymerase extension reactions were demonstrated using the labeled mixed construct, ThermoSequenase (Amersham), dNTPs and α-S-dNTPs (Amersham). 45 μl of the mixed construct was supplemented with 67.5 μl of 1× Walk buffer and 7 μl of ThermoSequenase (diluted 1:32 with ThermoSequenase dilution buffer, Perkin Elmer). 25 μl aliquots of this solution were placed into four 0.5 ml PCR tubes, preheated for 2 min at 45° C. and combined with 25 μl of preheated “10 μM α-S-dATP”, 10 μM α-S-dTTP”, 10 μM α-S-dGTP”, or “1 μM α-S-dCTP” solutions. The reaction was performed for 10 min at 45° C., stopped by adding 8 μl of “Stop” solution and the constructs were ethanol precipitated. Recovered oligonucleotide pellets were dissolved in 10 μl of TE buffer. C. dd(-N)-Blocking Reactions and Subsequent Walking “dd(-N)-blocking” reactions were demonstrated using the same mixed construct, ThermoSequenase and 4 mixtures of three ddNTPs (BMB). In the first experiment, 36 μl of the mixed labeled construct was supplemented with 414 μl of 1× Walk buffer, and 18 μl of ThermoSequenase (diluted 1:32). 25 μl aliquots of this solution were placed into sixteen 0.5 ml PCR tubes, preheated for 2 min at 45° C. and combined with 25 μl of preheated balanced “dd(-N) mixes” of different concentration (1/10, 1/100, 1/1000, and 1/10,000 of stock concentration). The reactions were performed for 5 min at 45° C., stopped by adding 8 μl of “Stop” solution and the constructs were ethanol precipitated. In the second experiment 22.5 μl of the mixed labeled construct was supplemented with 90 μl of 1× Walk buffer and 8 μl ThermoSequenase (diluted 1:32). 25 μl aliquots of this solution were placed into four 0.5 ml PCR tubes, preheated for 2 min at 45° C. and combined with 25 μl of preheated non-balanced “dd(-N) mixes.” The reactions were performed for 10 min at 45° C. and processed as described before. Recovered oligonucleotide pellets were washed with 80% ethanol, dried, and dissolved in 10 μl of TE buffer. To complete the N-walk reaction cycle, extension reactions were performed on the dd(-N)-blocked oligonucleotides. To show that the unblocked DNA ends could be extended by DNA polymerase, one half (5 μl) of each product of the blocking experiment above was supplemented with Walk buffer, 100 μM dATP, 100 μM dTTP, 100 μM dGTP, and 10 μM dCTP, and 1 U of ThermoSequenase, incubated for 15 min at 45° C., and stopped by adding 1 μl of 100 mM EDTA. D. Gel Electrophoretic Analysis A standard denaturing 16% polyacrylamide sequencing gel was run under standard conditions (Ausubel et al,. 1991). The 32P-labeled oligonucleotide polymerase extension products were detected and quantitated using a Molecular Dynamics 400A PhosphoImager and ImageQuant software. FIG. 24 shows the results of single-base extension experiment. Lane 1 represent primer A (21 bases), primer G (23 bases), primer T (25 bases), and primer C (28 bases) before extension. Lanes 2-5 represent products of single-base extension reactions in the presence of 1 μM α-S-dCTP, 10 μM α-S-dGTP, 10 μM α-S-dTTP, and 10 μM α-S-dATP, respectively. Arrows indicate the positions of elongated products. As expected primer G incorporated two guanine bases and migrates as a 25-mer, while each of the other primers were extended by a single base. The results presented in FIG. 24 show that under specific conditions a single-base extension can be performed near completion without any noticeable misincorporation into incorrect positions. FIG. 25 shows the results of the dd(-N)-blocking reactions using different concentrations of “dd(-A) mix” (lanes 1-4), “dd(-T) mix” (lanes 5-8), “dd(-G) mix” (lanes 9-12), and “dd(-C) mix” (lanes 13-16). Lanes 1, 5, 9, and 13 correspond to 1/10,000 of stock concentration; lanes 2, 6, 10, and 14 correspond to 1/1000 of stock concentration; lanes 3, 7, 11, and 15 correspond to 1/100 of stock concentration; and lanes 4, 8, 12, and 16 correspond to 1/10 of stock concentration of “dd(-N) mixes.” The results indicate that the dd(-N)-blocking reactions are highly specific and very efficient. Practically no primers remain unblocked except the selected primers, which, in turn, show no detectable misincorporation of ddNTPs. FIG. 26 shows extension of those primers that should still have 3′ OH groups after the blocking reactions. Lanes 1, 3, 5, and 7 contain the oligonucleotide mixture after the blocking reactions with “dd(-A)”, “dd(-T)”, “dd(-G)”, and “dd(-C)” mixes, respectively. Lanes 2, 4, 6, and 8 contain the products of polymerase extension of the DNA in lanes 1, 3, 5, and 7, respectively. Lane 9 contains unextended primers. Each of the primers that was not blocked with the dideoxyribonucleotide mix could be efficiently extended to the end of the template strand by DNA polymerase. Taken together with the results of the N-extension reactions shown in FIG. 24 and FIG. 25, the results shows that base walking and termination (and therefore multiple base sequencing reactions) are feasible. EXAMPLE 8 DNA Random Nicking Using Fe/EDTA and DNase I Random nicking reactions were performed on a circular, double-stranded plasmid and linear PCR DNA molecules, using a chemical Fenton reaction for creation of hydroxyl radicals (Hertzberg and Dervan, 1984; Price et al., 1992), and enzymatic treatment with DNase I in the presence of Mn++ cations (Campbell et al, 1980). The radioactively labeled products of cleavage were analyzed by gel electrophoresis. A. DNA Preparation A 489 bp pUC19 DNA fragment (bp 1714-1225) was amplified from pUC19 plasmid DNA (New England BioLabs) using 32P labeled pUC19 primer 2 (5′-TTATCTACACGAAGGGGAGTCAGA-3′; SEQ ID NO: 14) and biotinylated pUC19 primer 1 (5′ Biotin-GGTAACAGGATTAGCAGAGCGAGG-3′; SEQ ID NO: 13). To radioactively label primer 2, 1 μl of 10 μM pUC19 primer 2 was combined with 2.5 μl 10× Kinase buffer (BMB), 4 μl 32P γ-ATP (Amersham), 16.5 μl H2O, and 1 μl T4 kinase (BMB), incubated at 37° C. for 1 h, stopped by adding 3 μl 100 mM EDTA, heated for 10 min at 75° C. and adjusted with 22 μl H2O to final volume of 50 μl. To perform PCR amplification, 50 μl of 32P labeled primer 2 was combined with 4 μl of 10 μM biotinylated primer 1, 20 μl of GeneAmp 10×PCR buffer (500 mM KCl, 100 mM Tris-HCl, pH 8.3, 15 mM MgCl2, and 0.01% gelatin; Perkin Elmer), 3 μl pUC19 DNA (1 ng/μl), 8 μl 2.5 mM dNTP, 114 μl H2O and 1 μl AmpliTaq (5 U/μl; Perkin Elmer). Amplifications were performed in two 100 μl volumes using DNA Thermo Cycler (Perkin Elmer) and 20 cycles of polymerization reaction comprising of: 30 sec of denaturing at 94° C., 30 sec of primer annealing at 62° C., 1 min of extension at 72° C. Amplified DNA was precipitated with ethanol, dried and dissolved in 50 μl TE buffer. To immobilize DNA, 50 μl of paramagnetic streptavidin-coated beads (Dynabeads M-280 Streptavidin; Dynal) were washed 3 times using magnetic separator (Life Technologies) and 1×B & W buffer, resuspended in 50 μl of 2×B & W buffer, mixed with 50 μl of PCR amplified DNA fragment, and incubated at 37° C. for 1 h using occasional mixing by gently tapping the tube. Immobilized DNA was washed 3 times with 1×B & W buffer and finally resuspended in 50 μl of TE buffer. The buffers used are as follows. GeneAmp 10×PCR buffer: 500 mM KCl, 100 mM Tris-HCl, pH 8.3, 15 mM MgCl2, and 0.01% gelatin; Perkin Elmer). 2×B & W buffer: 10 mM Tris-HCl, pH 7.5, 1 mM EDTA, 2.0 M NaCl. TE buffer 10 mM Tris-HCl, pH 7.5, 0.1 mM EDTA. 1×DNase I buffer: 50 mM Tris-HCl, pH 7.5, 1 mM MnCl2, 100 mg/ml BSA. “Stop” buffer: 100 mM thiourea, 1 mM EDTA. B. Chemical Nicking of Immobilized DNA with Fe/EDTA 25 μl of immobilized DNA was additionally washed 2 times with 50 μl of 10 mM Tris-HCl buffer, pH 7.5, and resuspended in 75 μl of the same buffer at the bottom of 1.5 ml Eppendorf tube. 5 μl were taken as a control. 10 μl of freshly-prepared Fe/EDTA complex (20 mM ammonium iron(II) sulfate/40 mM EDTA), 10 μl of 10 mM sodium ascorbate and 10 μl of 0.3% H2O were mixed quickly on the tube wall and combined with 70 μl of the immobilized DNA (Price and Tullius, 1992). The reaction was performed at room temperature and 25 μl aliquots were removed after 15 sec, 30 sec, 1 min, and 2 min of incubation with Fe/EDTA. The reaction was stopped by adding 100 μl of “Stop” buffer. The suspension was washed 3 times with “Stop” buffer followed by 2 washes with TE buffer. C. Enzymatic Nicking of Immobilized DNA with DNase I 25 μl of immobilized DNA was additionally washed 2 times with 50 μl of DNase I buffer and resuspended in 105 μl of the same buffer. 5 μl were taken as a control; 100 μl of the immobilized DNA was preincubated at 15° C. DNase I (1 mg/ml; BMB) was diluted 1:1,000,000 with DNase I buffer and 5 μl (50 pg) was added to DNA. The reaction was performed at 15° C. and 25 μl aliquots were removed after 1 min, 2 min, 5 min, and 10 min of incubation with DNase I and mixed with 25 μl of 100 mM EDTA. The suspension was washed 2 times with 1×B & W buffer followed by 2 washes with TE buffer. D. Electrophoretic Separation and Analysis A standard denaturing 6% polyacrylamide sequencing gel was run under standard conditions (Ausubel et al., 1991). The 32P-labeled and nicked DNA products were detected and quantitated using a Molecular Dynamics 400A PhosphoImager and ImageQuant software. FIG. 27 shows that the patterns of DNA degradation caused by Fe/EDTA and DNase I treatment are nearly random. Lanes 1, 2, 3, 4, and 5 and 6, 7, 8, 9, and 10 correspond to 0, 15 sec, 30 sec, 1 min, 2 min, and 0, 1 min, 2 min, 5 min, 10 min of incubation of immobilized DNA with Fe/EDTA and DNase I, respectively. EXAMPLE 9 Efficient Conditioning of Fe/EDTA Introduced Breaks and Random DNA Sequencing Fe/EDTA treatments introduce 1 base DNA gaps with a phosphate group at the 3′ end of the defect (Hertzberg and Dervan, 1984; Price and Tullius 1992). Different enzymatic reactions were tested, and it was found that the combined action of T4 DNA polymerase and exonuclease III can be efficiently used to repair the 3′ ends and expose 3′ hydroxyl (OH) groups effective for DNA polymerases. A. Fe/EDTA Treatment of PCR Amplified and Plasmid DNA Immobilized PCR amplified DNA (1 pmol) was processed with Fe/EDTA as described above in Example 8. 1 mg of pUC19 plasmid DNA was supplemented with 65 ml of 10 mM Tris-HCl, pH 7.5, placed at the bottom of 1.5 ml Eppendorf tube, and combined quickly with 10 ml Fe/EDTA (0.25 mM/0.5 mM), 10 μl 10 mM sodium ascorbate and 10 μl 0.3% H2O2. The reaction was performed at room temperature for 15 sec and stopped by adding 100 μl of “Stop” buffer (see Example 8). DNA was washed 2 times with “Stop” buffer and 2 times with TE buffer using Microcon 100 microconcentrator (Amicon) and recovered in 20 μl volume of H2O. B. Conditioning of Fe/EDTA-Introduced Breaks with Exonuclease III and T4 DNA Polymerase Four 1 μl (100 ng) aliquots of pUC19 DNA after Fe/EDTA treatment were mixed at 4° C. with 4 μl 5×T4 polymerase buffer (BMB), 1 μl 2.5 mM dNTP mix, 1 μl T4 DNA polymerase (1 U/μl; BMB), supplemented with 0, 0.1 U, 0.3 U, or 1U of diluted exonuclease III (exo III; 100 U/μl; BMB), adjusted with H2O to 20 μl and incubated at 37° C. for 30 min. After inhibition of exo III by heating the samples for 10 min at 70° C., 1 μl of fresh T4 DNA polymerase was added and the reactions performed at 12° C. for 1 h. The reactions were stopped by adding 2.5 μl 100 mM EDTA and TE buffer to 200 μl, extracted with phenol/chloroform and ethanol precipitated. DNA pellets were recovered, washed with 70 % ethanol, dried and dissolved in 10 μl of TE buffer. In the second study, 1 pmol of immobilized PCR amplified DNA that had been Fe/EDTA treated for 15 sec (prepared as in the Example 8) was washed with 50 μl of 1×T4 DNA polymerase buffer (BMB) and resuspended in 100 μl of 1×T4 DNA polymerase buffer supplemented with 125 mM dNTP and 0.1 U of exo III. DNA was incubated for 20 min at 37° C. and, after adding 1 μl of fresh T4 DNA polymerase, for another 20 min at 15° C. The reaction was stopped by adding 2 μl 0.5 M EDTA and the DNA suspension was washed 2 times with 100 μl of 1×B & W buffer and 2 times with TE buffer. C. Polymerase Extension Reactions 10 μl pUC19 DNA samples after Fe/EDTA treatment and conditioning with different amounts of exo III were supplemented with 20 μl of GeneAmp 10×PCR buffer, 8 μl 25 mM MgCl2, 25 pmol (80 μCi) of 32P α-dCTP (Amersham), 53 μl H2O and 1 μl of AmpliTaq (Perkin Elmer). The reaction proceeded s min at 45° C. and 5 min at 55° C. and was stopped by adding 3 μl of 10×DNA loading buffer. 50 μl (1 pmol) of immobilized, Fe/EDTA treated and conditioned DNA was washed with 50 μl of GeneAmp 1×PCR buffer and aliquoted (15 μl) into tubes #2, 3 and 4. Tube #1 contained about 300 fmol of immobilized and washed but not treated PCR DNA. After removing the buffers with magnetic separator, tubes 14 were supplemented with 30 μl of GeneAmp 1×PCR buffer, containing 0.75 U AmpliTaq and 100 nM 32P α-dATP, 100 nM 32P α-dATP/200 nM cold α-dATP, 100 nM 32P α-dATP, and 33 nM 32P α-dATP, respectively. Samples were incubated at 45° C. for 10 min and then terminated with 1 μl 0.5 M EDTA, washed once with B & W buffer, once with TE and 2 times with 0.1 M NaOH. DNA was released from magnetic beads by heating at 95° C. in 10 μl of standard sequencing loading buffer and fast separation from the beads by magnetic separator. D. Electrophoretic Analysis pUC19 DNA samples after Fe/EDTA treatment, conditioning and DNA polymerase labeling were run on 1% agarose gel in 1×TAE buffer, stained with ethidium bromide and analyzed using a cooled CCD camera. After this the DNA was electroblotted onto ZetaProbe (BioRad) nylon membrane and analyzed using PhosphoImager. FIG. 28 shows the stained gel (panel A) and autoradiogram (panel B). Lanes 1 and 7 contain non-conditioned Fe/EDTA treated DNA; lanes 2 and 8 contain DNA conditioned with T4 DNA polymerase only; lanes 3 and 9 contain DNA conditioned with combined action of T4 DNA polymerase and 0.1 U exo III; lanes 4 and 10 contain DNA conditioned with combined action of T4 DNA polymerase and 0.3 U exo III; lanes 5 and 11 contain DNA conditioned with combined action of T4 DNA polymerase and 1 U exo III; lanes 6 and 12 contain DNA conditioned with combined action of T4 DNA polymerase and 3 U exo III. Very little incorporation of 32P α-dATP was detected in non-conditioned (lanes 1 and 7) and T4 polymerase conditioned (lanes 2 and 8) DNA samples. Incubation with a very small amount of exo III increases efficiency of DNA labeling 100 times, indicating efficient removal of 3′ phosphate groups in Fe/EDTA treated DNA. A standard denaturing 6% polyacrylamide sequencing gel was run under standard conditions (Ausubel et al,. 1991). Fe/EDTA treated, conditioned and 32P α-dATP-labeled PCR DNA products were detected and quantitated using a Molecular Dynamics 400A PhosphoImager and ImageQuant software. FIG. 29 shows results of specific incorporation of 32P α-dATP into Fe/EDTA randomly nicked DNA. Lanes 1-3 correspond to labeling reactions performed at 30 nM, 100 nM, and 300 nM of α-dATP, respectively. Lane 4 corresponds to non-degraded control DNA incubated with 100 nM α-dATP. The data demonstrate the feasibility of the random nick DNA sequencing method. EXAMPLE 10 Additional Methods for Multibase Analysis This example describes additional biochemical reactions that generate DNA fragments sutiable for multi-base sequence analysis. These techniques extend the earlier described “random nick” approach, as well as several reactions which utilize random double-stranded (rds) breaks. Three steps are common for all the reactions described in this example. In the first step (step a), random double-stranded (rds) breaks are introduced in the DNA molecule by any of the methods described herein, including sonication, nebulization, irradiation, or enzymatic treatment, for example using DNase I in the presence of Mn++. A combination of sonication and DNase I degradation is particularly preferred in certain aspects of the invention. It is preferred that the distribution of the double stranded breaks along the DNA molecule is essentially random. In the second step (step b), the broken ends are conditioned or repaired to generate a 3′ hydroxyl group, as described herein above, for example using T4 DNA polymerase. While in certain aspects of the invention this step can be eliminated, particularly when certain enzymatic treatments are used to generate the double stranded breaks, it is particularly important when non-enzymatic methods for creating double stranded breaks are used. Physical methods of creating double stranded breaks, such as sonication and nebulization, usually generate DNA ends which cannot be efficiently ligated to an adaptor (approximately 1% efficiency). Conditioning or repairing treatment increases the ligation efficiency from about 1% to about 10%, and by using a combination of T4 DNA polymerase and exonuclease III, as described herein above, the ligation efficiency can be increased to almost 100%. In the third step (step c), the conditioned or repaired randomly broken ends are linked or attached to a double stranded oligonucleotide adaptor through ligation. An exemplary adaptor is the 3′-blocked oligonucleotide adaptor is depicted in FIG. 30A. Only the top (W) strand of this adaptor has a 5′-phosphate group that can be covalently linked to the 3′ OH group of the repaired DNA ends. In certain aspects of the invention, an adaptor that has a blocking group, for example a dideoxy- or NH2-group, at the 3′ end of only the top (W) strand is contemplated for use. However, adaptor-adaptor ligation is possible, thus reducing the efficiency of ligating the adaptor to the repaired ends of the DNA molecule. Therefore, more preferred is an adaptor that is blocked by the presence of a blocking group at both 3′ termini, which allows the concentration of adaptors to remain high during the ligation reaction and leads to very high efficiency of adaptor ligation to the blunt DNA ends. Additionally, the thymines in the W strand can be replaced by deoxyuracil, which allows for the destruction of the W strand of the adaptor using a combination of uracil DNA glycosylase (dU-glycosylase) and NaOH. In addition to generating a nick that can be used to prime DNA synthesis and strand displacement, as described in detail herein above, the adaptor allows the set of molecules terminated at specific base combinations to be selected from the pool of randomly terminated DNA fragments (FIG. 31). The selection can be performed in a variety of ways, including using the procedures described herein above for selection and isolation mono-, di- or tri-nucleotide base combinations. The adaptor also allows the selected set of DNA fragments to be amplified using multiple primer-extension or PCR. In this example the source DNA (DNA to be sequenced or mapped) is a PCR product, but linearized plasmid DNA can be also used. Furthermore, the use of a biotinylated primer and magnetic separations significantly simplifies the manipulations, but is not absolutely required. A. Random Nick Formation As described above, the adaptor can be used to generate a random nick, which can be used in conjunction with the walking and blocking (dd(-N)) methods described above. This protocol can be performed using an adaptor having a lower (C) strand that is not blocked at the 3′ end, or, as described in detail below, by displacing the 3′ blocked C strand and annealing a fresh, non-3′ blocked C primer. These protocols allow for the selection of DNA fragments terminating in specific multi-base strings (for example AnTmG, where n and m are greater than or equal to 1). B. Multi-Base Sequence Analysis This technique provides for the selection of DNA fragments with a specific base combination adjacent to the adaptor. It is achieved through a set of sequential biochemical reactions. For example, to select DNA fragments that have 5′-ATG-3′ base combination at their 5′ adapted termini, the following reactions are performed following the ligation of the adaptor as described above (FIG. 32). The excess, non-ligated adaptors are removed by washing, and the DNA sample is heated at a temperature sufficient to displace the bottom (C) strand, for example 65° C. Then a non-blocked C strand oligonucleotide is hybridized to the covalently attached oligo-adaptor W strand, and the excess W strand oligonucleotide is removed by washing. Next, the sample is incubated with blocking solution “A”, containing ddATP and an appropriate DNA polymerase, and then the sample is washed to remove the excess ddATP. During this step ddA is incorporated into the 3′ ends of the C strand primers that associated with fragments having an adenine at the 5′ position next to the adaptor, thus blocking these primers. The sample is then incubated with extension solution containing an appropriate DNA polymerase and dNTP mix with T substituted by dU. During this step all of the C-primers except those that are blocked by ddA will be extended. Next, the DNA sample is heated at a temperature sufficient to displace the blocked C strand, for example 65° C., a new non-blocked oligonucleotide primer C-A (FIG. 30B, where X represents A), which has the same sequence as the C strand plus an adenine residue at the 3′-end, is hybridized to the W strand. During this step the C-A primer will bind only to DNA molecules which contain A at the 5′ end adjacent to the adaptor, competing with the displaced ddA-blocked primers, as the other primers are stabilized by the extension step and cannot be displaced by the C-A primer. After the excess C-A primer is removed by washing, the DNA is incubated with blocking solution “T” (an appropriate DNA polymerase plus ddTTP), and the excess ddTTP is removed by washing. The DNA is then incubated with the dUTP containing extension solution as described above, and then the excess extension solution is removed by washing. Next, the displacement (heating) and hybridization procedure as described above is repeated using a C-AT primer (C strand oligonucleotide plus AT at the 3′ end; FIG. 30B, where X represents A and Y represents T). After removing the excess C-AT primer by washing, the DNA is then incubated with blocking solution “G” (an appropriate DNA polymerase plus ddGTP), and then the excess ddGTP is removed by washing. The DNA is then again incubated with the dU containing extension solution, as described above, and the excess solution is removed by washing. Next, the displacement (heating) and hybridization procedure as described above is repeated using a C-ATG primer (C strand oligonucleotide plus ATG at the 3′ end; FIG. 30B, where X represents A, Y represents T and Z represents G). After removing the excess C-ATG primer by washing, the DNA is incubated with extension buffer containing an appropriate DNA polymerase and dNTP mix without dUTP, wherein at least one of the dNTP's is labeled or incorporates an isolation tag. Then the DNA sample is incubated with dU-glycosylase, and heated to 95° C., to degrade all intermediate dU-containing extension products and the W strand of the adaptor (when uracil is incorporated in place of thymidine). The fully extended products, which have an ATG sequence at the 5′ end adjacent the adaptor, are detected by a label incorporated into the extended strand, or by a label incorporated into the 5′ end of the C-ATG primer. Alternatively, these strands can be isolated using a tag incorporated into the extended strands or the C-ATG primer, and then detected as described above. Furthermore, using a standard adaptor as shown in FIG. 30A, single base sequencing can be performed on any fragment using the four C-X oligonucleotides (C-A, C-T, C-C and C-G), as shown in FIG. 30B. In a similar manner, two-base analysis can be conducted using the 16 C-XY oligonucleotides, and three-base analysis can be conducted using the 64 C-XYZ oligonucleotides. The use of the C-ATG primer can be eliminated through the use of a blocking dd(-G) solution as described in detail above. In this case, after the C-AT oligonucleotide has been annealed, the DNA in incubated with blocking solution dd(-G) (an appropriate DNA polymerase plus ddNTP mix without ddGTP), and then washed. At this step all of the C-AT primers will be blocked by ddNTPs except those which have a G base in the next adjacent position. Then the DNA is incubated with extension buffer containing an appropriate DNA polymerase and dNTP mix without dUTP, and the DNA sample is incubated with dU-glycosylase, and heated to 95° C., to degrade all intermediate dU-containing extension products and the W strand of the adaptor (when uracil is incorporated in place of thymidine) as described above. The filly extended products can then be detected or isolated as described above. The filly extended products can also be used for linear amplification by primer extension or amplification by PCR. Alternatively, as shown in FIG. 33A, a single primer-selector can be hybridized to a single-stranded template, followed by incubation with an extension solution containing a dNTP mix and a DNA polymerase (Guilfoyle et al., 1997). Another method to perform the selection step on a double-stranded template in one step by using a single primer-selector is shown in FIG. 33B (Huang et al., 1992; Vos et al., 1995). For example, to select for the ATG combination the C-ATG primer is directly hybridized to DNA to displace the blocked C strand and a short region at the 5′ end of the DNA fragment. The DNA is then incubated with the extension solution, containing dNTP mix and a DNA polymerase with 5′ exonuclease activity. All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods, and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the invention. 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The government owns rights in the present invention pursuant to grant number MCB 9514196 from the National Science Foundation. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention overcomes these and other drawbacks inherent in the prior art by providing methods and compositions for the analysis of nucleic acids, in particular for sequencing and mapping nucleic acids using double-stranded strand replacement reactions. These methods result in accurate sequencing reactions, in certain aspects due to very short extension reactions, and thus produce more useful sequence data from large templates, which overcome the problems inherent in single-stranded sequencing techniques. The present invention also provides new and powerful techniques for analyzing telomere length, telomere and subtelomeric sequence information, and quantitating the length and number of single-stranded overhangs present in telomeres. First provided are methods of creating or selecting one or more nucleic acid products that terminate with at least a first selected base. These terminated nucleic acid products and populations thereof may be used in a wide variety of embodiments, including, but not limited to, nucleic acid sequencing, nucleic acid mapping, and telomere analysis. The methods of creating one or more nucleic acid products that terminate with at least a first selected base generally comprise contacting at least a first substantially double stranded nucleic acid template comprising at least a first break on at least one strand with at least a first effective polymerase and a terminating composition comprising at least a first terminating nucleotide, the base of which corresponds to the selected base, under conditions effective to produce a nucleic acid product terminated at the selected base. The methods may first involve the synthesis, construction, creation or generation of the substantially double stranded nucleic acid template that comprises at least a first break on at least one strand. In which case, “contacting” the template with the effective polymerase and terminating composition forms the second part of the method. The term “template,” as used herein, refers to a nucleic acid that is to be acted upon, generally nucleic acid that is to be contacted or admixed with at least a first effective polymerase and at least a first nucleotide substrate composition under conditions effective to allow the incorporation of at least one more nucleotide or base into the nucleic acid to form a nucleic acid product. In many embodiments of the present invention, the nucleic acid product generated is a nucleic acid product that terminates with at least a first selected base. In some cases “template” means the target nucleic acids intended to be separated or sorted out from other nucleic acid sequences within a mixed population. “Substantially or essentially double stranded” nucleic acids or nucleic acid templates, as used herein, are generally nucleic acids that are double-stranded except for a proportionately small area or length of their overall sequence or length. The “proportionately small area” is an area lacking double stranded sequence integrity. The “proportionately small area lacking double stranded sequence integrity” may be as small as a single broken bond in only one strand of the nucleic acid, i.e., a break or “nick” within the double stranded nucleic acid molecule. The “proportionately small area lacking double stranded sequence integrity” may also be a gap produced within the double stranded nucleic acid molecule by excision or removal of at least one base or nucleotide. In these cases, the “substantially double stranded nucleic acids” may be described as being double-stranded except for a proportionately small area of single-stranded nucleic acid. “Proportionately small areas of single-stranded nucleic acids” are those corresponding to single-stranded areas, stretches or lengths of one, two, three, four, five, six, seven, eight, nine or about ten bases or nucleotides, as may be produced by creating a gap within the double stranded nucleic acid molecule by excision or removal of one, two, three, four, five, six, seven, eight, nine or about ten bases or nucleotides. In certain aspects of the invention, larger “proportionately small areas of single-stranded nucleic acids” are preferred, for example those corresponding to single-stranded areas, stretches or lengths of 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or about 100 bases or nucleotides, as may be produced by creating a gap within the double stranded nucleic acid molecule by excision or removal of 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or about 100 bases or nucleotides. In particular embodiments, even larger gaps may be created. The “proportionately small area of single-stranded nucleic acid” within a substantially double stranded nucleic acid may occur at any point within the substantially double stranded nucleic acid molecule or template, i.e., it may be terminal or integral. “Terminal portions of single-stranded nucleic acid” within a substantially double stranded nucleic acid are generally “overhangs”. Such “overhangs” may be naturally occurring overhangs, such as the area defined at the ends of telomeric DNA. “Overhangs” may also be engineered, i.e., created by the hand of man, using one or more of the techniques described herein and known to those of skill in the art. “Integral portions of single-stranded nucleic acid” within substantially double stranded nucleic acids, as used herein, will generally be engineered by the hand of man, again using one or more of the techniques described herein and known to those of skill in the art. The term “double stranded”, as applied to nucleic acids and nucleic acid templates, is generally reserved for nucleic acids that are completely double-stranded and that have no break, gap or single-stranded region. This allows “substantially double stranded” to be generally reserved for broken, nicked and/or gapped substantially double stranded nucleic acids and templates and substantially double stranded nucleic acids and templates that comprise at least a first single-stranded nucleic acid overhang. The templates for use in the invention may be in virtually any form, including covalently closed circular templates and linear templates. Both “native or natural” and “recombinant” nucleic acids and nucleic acid templates may be employed. “Recombinant nucleic acids”, as used herein, are generally nucleic acids that are comprised of segments of nucleic acids joined together by means of molecular biological techniques, i.e., by the hand of man. Although the nucleic acids for use in the methods will generally have been subjected to at least some isolation, and are thus not free from mans' intervention, “native and natural” nucleic acids and nucleic acid templates are intended to mean nucleic acids that have undergone less molecular biological manipulation and more correspond to the genomic DNA or fractions or fragments thereof. The templates may also be derived from any initial nucleic acid molecule, sample or source including, but not limited to, cloning vectors, viruses, plasmids cosmids, yeast artificial chromosomes (YACs), bacterial artificial chromosomes (BACs) and chromosomal and extrachromosomal nucleic acids isolated from eukaryotic organisms, including, but not limited to, yeast, Drosophila and mammals, including, but not limited to, mice, rabbits, sheep, rats, goats, cattle, pigs, and primates such as humans, chimpanzees and apes. In certain embodiments, the template may be created by cleavage from a precursor nucleic acid molecule. This generally involves treatment of the precursor molecule with enzymes that specifically cleave the nucleic acid at specific locations. Examples of such enzymes include, but are not limited to, restriction endonucleases, intron-encoded endonucleases, and DNA-based cleavage methods, such as triplex and hybrid formation methods, that rely on the specific hybridization of a nucleic acid segment to localize a cleavage agent to a specific location in the nucleic acid molecule. In other embodiments, the template may be created by amplifying the template from a precursor nucleic acid molecule or sample. The amplified templates generally include a region to be analyzed, i. e. sequenced, and can be relatively small, or quite large in various embodiments. In general, “amplification” may be considered as a particular example of nucleic acid replication involving template specificity. Amplification may be contrasted with non-specific template replication, i.e., replication that is template-dependent but not dependent on a specific template. “Template specificity” is here distinguished from fidelity of replication, i.e., synthesis of the proper polynucleotide sequence, and nucleotide (ribo- or deoxyribo-) specificity. “Template specificity” is frequently described in terms of “target” specificity. Target sequences are “targets” in the sense that they are desired to be separated or sorted out from other nucleic acids. Amplification techniques have been designed primarily for this “sorting out”. Amplification reactions generally require an initial nucleic acid sample or template, appropriate primers, an amplification enzyme and amplification reagents, such as deoxyribonucleotide triphosphates, buffers, and the like. In the sense of this application, a template for amplification (or “an amplification template”) refers to an initial nucleic acid sample or template, and does not refer to the “substantially double stranded nucleic acid template comprising at least a first break on at least one strand”. Therefore, as used herein, “an amplification template” is a “pre-template”. As used herein, the terms “amplifiable and amplified nucleic acids” are used in reference to any nucleic acid that may be amplified, or that has been amplified, by any amplification method including, but not limited to, PCR™, LCR, and isothermal amplification methods. Thus, the “substantially double stranded nucleic acid templates that comprise at least a first break on at least one strand” may be amplified nucleic acids or amplified nucleic acid products as well as templates for the methods of the invention. Widely used methods for amplifying nucleic acids are those that involve temperature cycling amplification, such as PCR™. Isothermal amplification methods such as strand displacement amplification are also routinely employed to amplify nucleic acids. All such amplification methods are appropriate to amplify “templates” for use in the invention from precursor nucleic acids or “pre-templates”. As used herein, the term “PCR™” (“polymerase chain reaction”) generally refers to methods for increasing the concentration of a segment of a template sequence in a mixture of genomic DNA without cloning or purification, as described in U.S. Pat. No. 4,683,195 and U.S. Pat. No. 4,683,202, each incorporated herein by reference. The process generally comprises introducing at least two oligonucleotide primers to a DNA mixture containing the desired template sequence, followed by a sequence of “thermal cycling” in the presence of a suitable DNA polymerase. The two primers are complementary to their respective strands of the double stranded template sequence. To effect amplification, the mixture is denatured and the primers then annealed to their complementary sequences within the template molecule. Following annealing, the primers are extended with a polymerase so as to form a new pair of complementary strands. In PCR, the steps of denaturation, primer annealing and polymerase extension are generally repeated many times, such that “denaturation, annealing and extension” constitute one “cycle”. Thus, “thermal cycling” means the execution of numerous “cycles” to obtain a high concentration of an amplified segment of the desired template sequence. As the desired amplified segments of the template sequence become the predominant sequences in the mixture, in terms of concentration, they are said to be “PCR™ amplified”. As used herein, the terms “PCR™ product”, “PCR™ fragment” and “amplification product” refer to the resultant mixture of compounds after two or more cycles of the PCR™ steps of denaturation, annealing and extension are complete. These terms encompass the case where there has been amplification of one or more segments of one or more target sequences. “PCR™ products and fragments” can naturally act as the broken, nicked or gapped substantially double stranded nucleic acid templates for use in the invention. Once a suitable or desired nucleic acid precursor, pre-template or sample composition has been obtained, a wide variety of substantially double stranded nucleic acid templates may be created for use in the claimed methods. In certain embodiments, even double stranded nucleic acid templates may be generated that comprise at least a first break substantially at the same position on both strands of the template. The most evident utility of this aspect of the invention is in producing nucleic acid fragments of a manageable size for further analysis, wherein such fragmentation is required. In certain of the preferred sequencing and mapping embodiments, the substantially double stranded nucleic acid template will comprise at least a first break on only one of the two strands. This is advantageous in that the product or products are generated from the same strand, leading to more direct and rapid analysis. In certain of the sequencing and mapping aspects of the invention, having the strand replacement start at a defined point on one strand is advantageous, particularly where analysis of the size of the products of the reaction, particularly the differential size of a population of products, is necessary. However, in a most general sense, creating a break on only one strand operably means that only one break is present in the region or target region of the individual nucleic acid molecule being analyzed or utilized. The target region is defined as a region of sufficient length to yield useful information and yet to allow the required volume of data to be generated in relation to the original nucleic acid subjected to the analysis. Thus, breaks at a distant region of the same nucleic acid molecule, outside of the target region, or breaks in the same general target region of a population of nucleic acid molecules, can exist and yet the target will still be considered to contain a “functional break” on only one strand. In any event, in most aspects of the invention, the presence of additional breaks or nicks is not a drawback, so long as a 3′ hydroxyl group can be generated in the presence of a template strand that can support the incorporation of at least one complementary base. The presence of multiple breaks on both strands is either useful, as one can initiate synthesis at a plurality of points as only the “first-encountered” break forms the functional break for extension and/or termination, or non-functional, and thus irrelevant, in most aspects of the invention. For example, although synthesis products may be produced from breaks on both strands, utilizing the labeling techniques in conjunction with the isolation or immobilization techniques as disclosed herein products from only one strand and closest to the detectable label are detected in the final analysis step, thus eliminating the requirement for a break on only one strand in the most rigid sense. In general, the complexity of the nicking or breaking reaction is directly correlated with the complexity of the labeling and/or isolation or immobilization procedures. In aspects wherein a nick or break is generated at a single position in a population of identical templates, only a single detectable label is required to analyze the products of the extending and/or terminating reaction. The presence of additional breaks or nicks is made most useful when employed with additional labels and/or the isolation of a subset of the nucleic acid products prior to analysis. Although by no means limiting, in substantially double stranded nucleic acid templates that comprise at least a first integral break or gap on only one strand, it is convenient to identify the intact or “unbroken” strand as the “template strand”, and the strand that comprises at least a first integral break or gap as the “non-template strand”. In those methods of the invention that encompass sequencing, the template strand will generally act as the guideline for the incorporation of one or more complementary bases or nucleotides into the “non-template strand”, which is herein defined as the “extension of the non-template strand”. The “extension” of the non-template strand may be an extension by a single base or nucleotide only, in which case the “extension” is inherently an “extension and termination”. The single base or nucleotide incorporated into the non-template strand is thus a “terminating base or nucleotide”. This allows the broken, nicked or gapped strand to also be referred to as “the terminated strand”. Alternatively, the “extension” of the non-template strand may be an extension by two, three or more, or a plurality of, bases or nucleotides, and/or an extension to create a population of extended non-template strands each including a different number of incorporated bases or nucleotides. In these cases, “termination” is not co-extensive with “extension”, and termination may even be delayed until after the incorporation of a significant number of “extending” bases or nucleotides. Thus, the broken, nicked or gapped strand that formed the starting point for the two, three or multiple base extension may also be termed “the synthesized strand”. In contrast, in substantially double stranded nucleic acid templates that comprise a terminal single-stranded portion or “overhang”, it may be more convenient to identify the single-stranded overhang portion as the template strand. This is essentially because the art uses an existing “hybridizable” nucleic acid portion as a “template”, e.g., in the sense that a sufficiently complementary probe or primer can hybridize to the template. As used herein, the term “probe” refers to an oligonucleotide, i.e., a contiguous sequence of nucleotides, whether occurring naturally as in a purified restriction digest or produced synthetically, recombinantly or by PCR™ amplification, that is capable of hybridizing to a nucleic acid of interest or portion thereof. Although probes may be single-stranded or double-stranded, the hybridizing probe described above in reference to binding to a nucleic acid overhang will generally be single-stranded. Probes are often labeled with a detectable label or “reporter molecule” that is detectable in a detection system, including, but not limited to fluorescent, enzyme (e.g., ELISA), radioactive, and luminescent systems. The term “primer”, as used herein refers to an oligonucleotide, whether occurring naturally as in a purified restriction digest or produced synthetically, that is capable of acting as a point of initiation of nucleic acid synthesis when placed under conditions in which the synthesis of a primer extension product that is complementary to a nucleic acid strand of interest is induced, e.g., in the presence of nucleotides and an inducing agent such as DNA polymerase and at a suitable temperature and pH. A primer must be sufficiently long to prime the synthesis of extension products in the presence of the inducing agent The exact length of an effective primer depends on factors such as temperature of extension, source of primer and the particular extension method. Primers are preferably single stranded for maximum efficiency in amplification (but may be double stranded if first treated to separate the strands before use in preparing extension products). Primers are often preferably oligodeoxyribonucleotides. The invention further provides various methods for generating the substantially double stranded, broken nucleic acid templates. Certain of the template-generation methods are generic to the creation of various types of template sought. For example, methods are disclosed that are capable of creating substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken. Equally, distinct methods are provided for creating substantially double stranded nucleic acid templates in which both template strands are broken versus those for creating substantially double stranded nucleic acid templates in which only one of the template strands is broken. Enzymatic methods are provided that are universally applicable to creating substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken. Such methods generally comprise creating the template by contacting a double-stranded or substantially double-stranded nucleic acid with a combined effective amount of at least a first and second breaking enzyme combination. A “combined effective amount of at least a first and second breaking enzyme combination” is a combined amount of at least a first and second enzyme effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first break. Examples of broadly effective “enzymatic breaking combinations” are uracil DNA glycosylase in combination with an effectively matched endonuclease, such as endonuclease IV or endonuclease V. In light of the present disclosure, those of ordinary skill in the art will understand that the use of a uracil DNA glycosylase-endonuclease combination is predicated on the prior incorporation of at least a first uracil base or residue into the nucleic acid molecule that is to form the template. Accordingly, in certain embodiments, the invention provides for the creation of a template by generating a double-stranded or substantially double-stranded nucleic acid molecule comprising at least a first uracil base or residue and contacting the uracil-containing nucleic acid molecule with a combined effective amount of a first, uracil DNA glycosylase enzyme and a second, endonuclease IV enzyme or endonuclease V enzyme. The use of endonuclease V in the combination is generally preferred. A “combined effective amount of a first, uracil DNA glycosylase enzyme and a second, endonuclease IV or V enzyme” is a combined amount of the enzymes effective to create a substantially double stranded nucleic acid template comprising at least a first gap corresponding in position to the position of the at least a first uracil base or residue incorporated into the uracil-containing nucleic acid molecule. The incorporation of at least a first uracil base or residue into a double-stranded or substantially double-stranded nucleic acid molecule is generally achieved by incorporation of a dUTP residue in the nucleic acid synthesis reaction. In certain aspects of the invention it is desired to incorporate a single uracil base or residue into a specific location near the 5′ end of the nucleic acid template. In a general sense, this may be accomplished by methods comprising contacting a precursor molecule with at least a first and a second primer that amplify the template when used in conjunction with a polymerase chain reaction, wherein at least one of the first or second primers comprises at least a first uracil base, and conducting a polymerase chain reaction to create an amplified template containing a single uracil residue corresponding to the location of the uracil base in the uracil-containing primer. In certain aspects, both primers contain uracil, to produce an amplified template that contains a uracil residue near the 5′ end of both strands. In other embodiments, dUTP will be used in the synthesis of the template strand, thus incorporating multiple uracil residues into the template. Incorporation of at least a first uracil base or residue only into one of the strands of the nucleic acid molecule allows for the subsequent generation of a substantially double stranded nucleic acid template in which only one of the template strands is broken, whereas incorporation of at least a first uracil base or residue into each of the strands of the nucleic acid molecule allows for the subsequent generation of a substantially double stranded nucleic acid template in which both of the template strands are broken. Certain chemical cleavage compositions are also appropriate for creating substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken. Such methods generally comprise creating the template by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of an appropriate chemically-based nucleic acid cleavage composition. An “effective amount of an appropriate chemically-based nucleic acid cleavage composition” is an amount of the composition effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first break. In yet further embodiments, substantially double stranded nucleic acid templates in which either only one or both of the template strands are broken may be created by contacting a substantially double-stranded nucleic acid with an effective amount of at least a first appropriate nuclease enzyme. An “effective amount of at least a first appropriate nuclease enzyme” is an amount of the nuclease enzyme effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first break. In different embodiments, the invention provides methods for making and using substantially double stranded nucleic acid templates in which the one or more breaks or gaps are either located at a specific point or points along the nucleic acid template, or in which the one or more breaks or gaps are located at a random location or locations along the nucleic acid template. These may be referred to as “specifically broken, nicked or gapped templates” and “randomly broken, nicked or gapped templates”, respectively. The methods for generating the specifically and randomly manipulated templates are generally different in principle and execution, although both nucleases and non-nuclease-based chemical or biological components may be used in various of the methods. In certain embodiments, a substantially double stranded nucleic acid template comprising at least a first break or gap at a specific point on at least one strand of the template is created by contacting a double stranded or substantially double-stranded nucleic acid with an effective amount of at least a first specific nuclease enzyme. Exemplary specific nuclease enzymes are f1 endonuclease, fd endonuclease or a restriction endonuclease. A preferred specific nuclease enzyme is f1 endonuclease. An “effective amount of at least a first specific nuclease enzyme” is an amount of the nuclease enzyme effective to create a substantially double stranded nucleic acid template that comprises at least a first break or gap at a specific point on at least one strand of the template. In other embodiments, the specific-type template is created by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of an appropriate specific chemical cleavage composition. An exemplary embodiment is wherein the specific chemical cleavage composition comprises a nucleic acid segment, such as a hybrid or triple helix forming composition, that is linked to a metal ion chelating agent The chelating agent binds a metal ion, and in the presence of a peroxide and a reducing agent, produces a hydroxyl radical that can nick or break a nucleic acid. The specificity of the cleavage is provided from the nucleic acid segment, which only hybridizes to or forms a triple helix at a specific location in the nucleic acid molecule to be broken or nicked. In certain cases, the hydroxyl radicals produced can diffuse, and thus a small region is broken or nicked, producing a gap. An “effective amount of at least a first specific chemical cleavage or triple helix-forming composition” is an amount of the composition effective to create a substantially double stranded nucleic acid template that comprises at least a first break or gap at a specific point on at least one strand of the template. For use in certain embodiments, particularly the random break incorporation and random break degradation sequencing embodiments, the creation of a substantially double stranded nucleic acid template comprising at least a first random break or gap on at least one strand will be preferred. Templates with one or more breaks or nicks located at one or more random points or locations along the nucleic acid template are termed “randomly nicked templates”. Suitable processes for creating such randomly nicked templates, or populations thereof, are collectively termed “random nicking”. “Random nicking” generally refers to a process or processes effective to generate a substantially double stranded nucleic acid template that comprises at least a first broken bond located at at least a first random position within the sugar-phosphate backbone of at least one of the two strands of the nucleic acid template. As used herein, a “randomly nicked template” is intended to mean “at least a randomly nicked template”. This signifies that at least one randomly-located broken bond is present, which broken bond may form the starting point or “substrate” for further manipulations, e.g., to convert the nick into a gap. A process of random nicking that creates at least a first randomly positioned broken bond in a strand of the template may then be extended to create a gap at that random point or position by excising at least the first base or nucleotide proximal to the broken bond. This then becomes a process of “random gapping” effective to prepare a “random gap template”, or a population thereof, comprising one or more gaps of at least a nucleotide in length positioned randomly within the nucleic acid template. In certain embodiments, particularly certain mapping and sequencing aspects, the creation of a substantially double stranded nucleic acid template comprising at least a first random break or gap on only one strand will be preferred. This is generally for ease of analysis of the information generated from a strand replacement reaction, but also has advantages as detailed above. Suitable methods that may be adapted to create a substantially double stranded nucleic acid template comprising at least a first random break or gap on at least one, or only one, strand are provided herein. The optimization of the random nicking methods to mono-stranded or dual-stranded nicking is generally based upon the correlation between the breaking or nicking agent, enzyme, chemical or composition and the time and conditions used to produce the break or nick. Agents that produce a given break or nick under one set of conditions, can produce a completely different break under different conditions. For example, a breaking or nicking agent that produces a single break or nick under one reaction condition, can in certain embodiments produce a plurality of breaks or nicks under a second, distinct reaction condition. Thus, the double stranded nucleic acid template comprising at least a first random break or gap on at least one, or only one, strand that is produced depends not only on the breaking or nicking agent used, but the conditions used to conduct the breaking or nicking reaction. In one embodiment, the at least randomly nicked template is created by generating a double-stranded or substantially double-stranded nucleic acid comprising at least a first randomly positioned exonuclease-resistant nucleotide, and contacting the nucleic acid with an effective amount of an exonuclease. Exemplary exonuclease-resistant nucleotides include, but are not limited to deoxyribonucleotide phosphorothioates and deoxyribonucleotide boranophosphates. The preferred effectively matched exonuclease is exonuclease III. In these embodiments, an “effective amount of an exonuclease” is an amount of the exonuclease effective to degrade the strand containing the exonuclease-resistant base to the position of the resistant base. The incorporation of at least a first randomly positioned exonuclease-resistant nucleotide into a double-stranded or substantially double-stranded nucleic acid molecule is generally achieved by utilizing extendable deoxynucleotides comprising the exonuclease-resistant feature during the synthesis of the nucleic acid precursor or template. The amount of exonuclease-resistant incorporated into the nucleic acid template can be controlled by adjusting the ratio of the extendable deoxynucleotides with and without the exonuclease-resistant feature used in the synthesis reaction. In alternate aspects of the present invention, the at least randomly nicked template is created by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of at least a first randomly-nicking or -breaking nuclease enzyme. Exemplary randomly-breaking nuclease enzymes are deoxyribonuclease I and CviJI restriction endonuclease. An “effective amount of at least a first randomly-nicking or -breaking nuclease enzyme” is an amount of the nuclease enzyme effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first randomly located broken bond within the template backbone. In yet a further aspect of the invention, the at least randomly nicked template is created by contacting a double-stranded or substantially double-stranded nucleic acid with a combined effective amount of at least a first and second randomly-breaking nuclease enzyme combination. Exemplary randomly-breaking enzymes for use as the first or second nuclease enzymes are the frequent-cutting restriction endonucleases Tsp509I, MaeII, TaiI, AluI, CviJI, NlaIII, MspI, HpaII, BstUI, BfaI, DpnII, MboI, Sau3AI, DpnI, ChaI, HinPI, HhaI, HaeIII, Csp6I, RsaI, TaqI and MseI, which may be used in any combination. A “combined effective amount of at least a first and second randomly-breaking nuclease enzyme combination or frequent-cutting restriction endonuclease combination” is a combined amount of the nuclease enzymes effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first randomly located broken bond within the template backbone. As used herein, the terms “nucleases”, “restriction endonucleases” and “restriction enzymes” refer to enzymes, generally bacterial enzymes, that cut nucleic acids. Mostly, the enzymes cut nucleic acids at or near specific nucleotide sequences, but certain enzymes, such as DNAase I, produce essentially random cuts or breaks. Further embodiments of randomly-nicked template creation rely on contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of a randomly-nicking or -breaking chemical cleavage composition. Throughout the variety of randomly-nicking or -breaking chemical cleavage compositions that may be employed, an “effective amount” is an amount of the chemical cleavage composition effective to create a substantially double stranded nucleic acid template in which either only one or both of the template strands comprise at least a first randomly located broken bond within the template backbone. In preferred embodiments, the random chemical cleavage compositions will comprise or react to produce a hydroxyl radical. Certain suitable randomly-breaking chemical cleavage compositions comprise a chelating agent, a metal ion, a reducing agent and a peroxide, as exemplified by compositions that comprise EDTA, an Fe 2+ ion, sodium ascorbate and hydrogen peroxide. In other embodiments, the randomly-breaking chemical cleavage composition comprises a compound, generally a dye, that produces a hydroxyl radical upon contact with a defined or specified wavelength(s) of light. Randomly-nicked templates may also be created by effectively irradiating with gamma irradiation, i.e., by contacting a double-stranded or substantially double-stranded nucleic acid with an effective amount of gamma irradiation. Effective application of one or more mechanical breaking processes may also be employed to create the randomly broken or nicked templates. Exemplary mechanical breaking processes include subjecting double-stranded or substantially double-stranded nucleic acids to effective amounts of: hydrodynamic forces, sonication, nebulization and/or freezing and thawing. In the methods of creating nucleic acid products that terminate with at least a first selected base, the at least nicked nucleic acid template is contacted with at least a first effective polymerase and at least a first effective terminating composition comprising at least a first terminating nucleotide, wherein the base of the terminating nucleotide corresponds to the selected base desired for nucleic acid incorporation and termination, “under conditions effective to produce a nucleic acid product terminated at the selected base”. “Under conditions effective to produce a nucleic acid product terminated at the selected base” means that the conditions are effective to permit at least one round of nucleotide extension and termination, thus incorporating at least one additional base or nucleotide (the selected base or corresponding nucleotide) into the nucleic acid product The “effective conditions” are thus “product-generating conditions”, “nucleotide extension and termination-permissive conditions” or “at least nucleotide extending and terminating conditions”. Fundamental aspects of the “effective, product-generating conditions” include conditions permissive or favorable to the necessary biological reactions, i.e., appropriate conditions of temperature, pH, ionic strength, and the like. The term “under conditions effective to produce a nucleic acid product terminated at the selected base” also means, in and of itself, “under conditions suitable and for a period of time effective to produce a nucleic acid product terminated at the selected base”. According to the intended use(s) of the selected base-terminated nucleic acid products, or populations thereof, the “effective, product-generating conditions and times” may also be termed “effective nucleic acid sequencing conditions” and/or “effective nucleic acid mapping conditions”. The “effective, product-generating conditions and times” will vary depending on the type of nucleic acid product or products that one wishes to generate: e.g., products in which the at least nicked nucleic acid template strand is extended with only a single base or nucleotide; or with only two selected bases or nucleotides; or with only three selected bases or nucleotides; or in which the at least nicked nucleic acid template strand is extended with a plurality of bases or nucleotides; and/or in which the at least nicked nucleic acid template is used to prime the synthesis of a population of extended nucleic acid strands, each terminated at a different point Inherent in the term “effective, product-generating conditions” is the concept that the “at least a first effective polymerase” will be a polymerase that is effective to generate the type of nucleic acid product or products desired under the extending or polymerizing conditions applied Equally, the “at least a first effective terminating composition” will be a terminating composition effective to generate the type of terminated nucleic acid product or products desired under the termination conditions applied. Also inherent in the term “effective, product-generating conditions” is the concept that the “effective polymerase” is a polymerase that is effective to act on the precise type of nick, break or gap in the template under the extending or polymerizing conditions applied. This means that the polymerase has synthetic activity under the chosen conditions, i.e., the polymerase is capable of catalyzing the addition of the desired type and number of bases or nucleotides using the nick, break or gap in the template as the “priming substrate”. The type of nick, break or gap in the template thus forms an “effective matched pair” with the selected polymerase. DNA molecules have “5′ and 3′ ends”, meaning that mononucleotides have been reacted to make oligonucleotides or polynucleotides in a manner such that the 5′ phosphate of one mononucleotide pentose ring is attached to the 3′ oxygen (from the original hydroxyl) of its neighbor in one direction via a phosphodiester linkage. Therefore, an end of an oligonucleotide or polynucleotide is referred to as the “5′ end” if its 5′ phosphate is not linked to the 3′ oxygen of a mononucleotide pentose ring and as the “3′ end” if its 3′ oxygen is not linked to a 5′ phosphate of a subsequent mononucleotide pentose ring. As used herein, a nucleic acid sequence, even if internal to a larger oligonucleotide or polynucleotide, may also be said to have 5′ and 3′ ends. In either a linear or circular DNA molecule, discrete elements are referred to as being “upstream” or 5′ of the “downstream” or 3′ elements. This terminology reflects the fact that transcription proceeds in a 5′ to 3′ fashion along the DNA strand. In embodiments where the break in the substantially double stranded nucleic acid template is a nick that comprises, or is reacted to comprise, a 3′ hydroxyl group, the effective polymerase will generally either have 5′ to 3′ exonuclease activity or strand displacement activity, or both. Effective polymerases in these categories include, for example, E. coli DNA polymerase I, Taq DNA polymerase, S. pneumoniae DNA polymerase I, Tfl DNA polymerase, D. radiodurans DNA polymerase I, Tth DNA polymerase, Tth XL DNA polymerase, M. tuberculosis DNA polymerase I, M. thermoautotrophicum DNA polymerase I, Herpes simplex-1 DNA polymerase, E. coli DNA polymerase I Klenow fragment, vent DNA polymerase, thermosequenase and wild-type or modified T7 DNA polymerases. In preferred embodiments, the effective polymerase will be E. coli DNA polymerase I, M. tuberculosis DNA polymerase I or Taq DNA polymerase. Where the break in the substantially double stranded nucleic acid template is a gap of at least a base or nucleotide in length that comprises, or is reacted to comprise, a 3′ hydroxyl group, the range of effective polymerases that may be used is even broader. In such aspects, the effective polymerase may be, for example, E. coli DNA polymerase I, Taq DNA polymerase, S. pneumoniae DNA polymerase I, Tfl DNA polymerase, D. radiodurans DNA polymerase I, Tth DNA polymerase, Tth XL DNA polymerase, M. tuberculosis DNA polymerase I, M. thermoautotrophicum DNA polymerase I, Herpes simplex-1 DNA polymerase, E. coli DNA polymerase I Klenow fragment, T4 DNA polymerase, vent DNA polymerase, thermosequenase or a wild-type or modified T7 DNA polymerase. In preferred aspects, the effective polymerase will be E. coli DNA polymerase I, M. tuberculosis DNA polymerase I, Taq DNA polymerase or T4 DNA polymerase. In those embodiments in which either the nicked or broken template does not initially comprise a 3′ hydroxyl group, such as when the template is generated by hydroxyl radicals (in certain instances) or certain physical or mechanical processes, the nicked template may still be manipulated or reacted to comprise the desired 3′ hydroxyl group. Methods for achieving this generally involve “conditioning” the non-3′ hydroxyl group containing position. In a preferred aspect of the invention, the “conditioning” involves exonuclease III treatment to remove the base or position lacking a 3′ hydroxyl group, leaving a 3′ hydroxyl group as a product of the removal reaction. Various methods are also available for terminating the nucleic acid extension to produce the one or more terminated nucleic acid products. For example, the terminating composition may simply comprise a terminating dideoxynucleotide triphosphate, the base of which corresponds to the selected base. Extension with a single base and termination thus occur simultaneously as the dideoxynucleotide triphosphate in incorporated into the template at the break or nick, preventing further addition or extension due to the absence of an available —OH group. In other embodiments, the terminating composition comprises a terminating deoxynucleotide triphosphate, the base of which corresponds to the selected base. Extension of the nicked strand with a single type of base and termination with that base still occur essentially simultaneously as only one type of deoxynucleotide triphosphate is available for incorporation into the template at the break or nick (with the number of bases incorporated into the nicked strand depending on the number of complementary bases in the corresponding or template strand), thus preventing further addition or extension due to the absence of other nucleotides. Where detection of the nucleic acid product or products is desired, the product or products will preferably comprise a detectable label or isolation tag. Inherent in the term “under conditions effective to produce a nucleic acid product terminated at the selected base” is the concept that the “effective terminating composition” is effective to incorporate a detectable label into the nucleic acid product or products under the terminating conditions applied, should such labeling be necessary or preferable for subsequent detection or execution of related sequencing or mapping techniques. The type of terminating composition and the type of label or tag in the nucleic acid product or products thus also form an “effective matched pair”. Accordingly, in any of the methods of the invention, the at least a first terminating nucleotide or nucleotides may comprise a detectable label or an isolation tag that is incorporated into the nucleic acid product or products. In certain aspects, the substantially double stranded nucleic acid template may comprise a detectable label or isolation tag incorporated into the template, and hence into the subsequent nucleic acid product or products, at a point other than the termination point. In other aspects, both the template and the terminating nucleotide or nucleotides may each comprise a detectable label or an isolation tag. Preferred aspects of the invention require the detection of the terminated nucleic acid product or products generated by the foregoing methods. In certain embodiments, the nucleic acid product or products will be separated, e.g., by electrophoresis, mass spectroscopy, FPLC or HPLC, prior to detection. The nucleic acid product or products will generally comprise a detectable label, and the nucleic acid product or products are detected by detecting the label. In certain aspects, the nucleic acid product or products will comprises an isolation tag, and the nucleic acid product or products are purified using the isolation tag, optionally prior to more precise detection or differentiation techniques. Suitable detectable labels and isolation tags are exemplified by radioactive, enzymatic and fluorescent labels; and biotin, avidin and streptavidin isolation tags. Detection is generally integral to the use of the invention in methods for sequencing nucleic acids, wherein the methods comprise detecting the nucleic acid product or products under conditions effective to determine the nucleic acid sequence of at least a portion of the nucleic acid. In certain embodiments, the introduction or incorporation of the at least a first selected base at the break or nick in the template allows for direct nucleic acid sequencing. These methods generally rely on the generation of a population of nucleic acid products randomly terminated at four selected bases, as exemplified by: a) creating a population of substantially double-stranded nucleic acid templates from a nucleic acid molecule to be sequenced, each of the templates comprising at least a first random break, preferably only on one strand; b) contacting the population of templates with an effective polymerase and a terminating composition comprising four distinct labeled or tagged terminating nucleotides, under conditions effective to produce a population of terminated nucleic acid products randomly terminated at four selected bases; c) detecting the population of randomly terminated nucleic acid products under conditions effective to determine the nucleic acid sequence of at least a portion of the original nucleic acid molecule. In certain embodiments, the population of templates is contacted with the terminating composition in four distinct reactions, or wells, each of the reactions comprising only one of the four distinct labeled or tagged terminating nucleotides. In other embodiments, the population of templates is contacted with the terminating composition in a single reaction, or well, wherein each of the four terminating nucleotides comprises a distinct, fluorescent label. In further sequencing embodiments, the introduction or incorporation of the at least a first selected base at the break or nick in the template acts as a primer for other, non-direct nucleic acid sequencing methods. An exemplary method is “Sanger”-based sequencing, originating at the nick or gap in the double-stranded template. Such a method may comprise: a) creating at least a first substantially double-stranded nucleic acid template from the nucleic acid molecule to be sequenced, the template comprising at least a first random break, preferably only on one strand; b) contacting the at least a first template with an effective polymerase and at least a first extending and terminating composition comprising four extending deoxynucleotide triphosphates and a labeled or tagged terminating dideoxynucleotide triphosphate, under conditions effective to produce a population of terminated nucleic acid products, each originating from the random break; c) detecting the terminated nucleic acid products under conditions effective to determine the nucleic acid sequence of at least a portion of the original nucleic acid molecule. Again, the four terminating bases may comprise distinct fluorescent labels. In addition to “Sanger-like” methods, still further analytical and sequencing methods also require the introduction or incorporation of at least one further base at the break or gap in the template in addition to the selected base. Thus, a first and a second selected base may be incorporated; or this may be described as incorporating a “specified base” in addition to the selected base. Production of a nucleic acid product comprising at least one specified base prior to termination at the selected base requires contacting the template with an effective polymerase and extending and terminating composition, wherein the extending composition comprises the extending specified base. These methods may be further defined as methods for identifying a selected dinucleotide sequence in the template strand of the nucleic acid template, the dinucleotide sequence being the complement of the specified and selected base incorporated into the non-template, or synthesized strand that originally contained the nick or gap. Such methods comprise: a) blocking the at least nicked template by contacting the at least nicked template with a first blocking composition comprising the three dideoxynucleotide triphosphates that do not contain the specified base, to create a blocked template; b) removing the first blocking composition from contact with the blocked template; c) contacting the blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the specified base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the selected base, under conditions effective to produce a nucleic acid product terminating with a dinucleotide sequence of the specified and selected base; and d) detecting the nucleic acid product under conditions effective to identify the selected dinucleotide sequence in the template strand of the nucleic acid template. Defining the selected dinucleotide sequence as a first and second base in a template strand of a nucleic acid template, such methods are defined as comprising: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base, to create a blocked template; b) removing the first blocking composition from contact with the blocked template; c) contacting the blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the second base, under conditions effective to produce a nucleic acid product terminating with a dinucleotide sequence complementary to the first and second base; and d) detecting the nucleic acid product under conditions effective to identify the selected dinucleotide sequence in the nucleic acid template. In such methods, step (c) may be conducted as a single extending and terminating step, comprising contacting with a composition that comprises both the extending deoxynucleotide triphosphate and the terminating dideoxynucleotide triphosphate. Step (c) may also be conducted as at least two distinct extending and terminating steps, comprising first contacting the template with an extending composition that comprises the extending deoxynucleotide triphosphate, and then contacting the template with a distinct terminating composition that comprises the terminating dideoxynucleotide triphosphate. Step (c) may comprise, in sequence, contacting the template with an extending composition that comprises the extending deoxynucleotide triphosphate, removing the extending composition from contact with the template, and contacting the template with a distinct terminating composition that comprises the terminating dideoxynucleotide triphosphate. The non-Sanger analytical and sequencing methods may also require the introduction or incorporation of at least two further bases at the break or gap in the template in addition to the selected base. Thus, the nicked template is subjecting to a series of blocking and washing, and extending and washing reactions prior to contact with the terminating composition, thereby producing an extended nucleic acid product comprising two, three or a series of additional bases preceding the selected, terminating base. Such methods allow for the identification of a selected trinucleotide sequence in a nucleic acid template, the trinucleotide sequence being the complement of the first and second specified bases and the selected base, the method comprising: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the first specified base, to create a first-blocked template; b) removing the first blocking composition from contact with the first-blocked template; c) extending the first-blocked template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the first specified base, to create a first-extended template; d) removing the first extending composition from contact with the first-extended template; e) blocking the first-extended template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the second specified base to create a second-blocked template; f) removing the second blocking composition from contact with the second-blocked template; g) contacting the second-blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the second specified base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the selected base, under conditions effective to produce a nucleic acid product terminating with a trinucleotide sequence of the first and second specified bases and the selected base; and h) detecting the nucleic acid product under conditions effective to identify a selected trinucleotide sequence in the nucleic acid sample. Defining the selected trinucleotide sequence as a first, second and third base in a template strand of a nucleic acid template, the foregoing methods are defined as comprising: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base to create a first-blocked template; b) removing the first blocking composition from contact with the first-blocked template; c) extending the first-blocked template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base to create a first-extended template; d) removing the first extending composition from contact with the first-extended template; e) blocking the first-extended template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base to create a second-blocked template; f) removing the second blocking composition from contact with the second-blocked template; g) contacting the second-blocked template with at least a first extending and terminating composition comprising an extending deoxynucleotide triphosphate containing the complement of the second base, and a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the third base, under conditions effective to produce a nucleic acid product terminating with a trinucleotide sequence complementary to the first, second and third bases; and h) detecting the nucleic acid product under conditions effective to identify the selected trinucleotide sequence in the nucleic acid sample. These methods may comprise: a) blocking the at least nicked template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base to create a first-blocked template; b) removing the first blocking composition from contact with the first-blocked template; c) extending the first-blocked template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base to create a first-extended template; d) removing the first extending composition from contact with the first-extended template; e) blocking the first-extended template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base to create a second-blocked template; f) removing the second blocking composition from contact with the second-blocked template; g) further extending the second-blocked template by contacting with a second extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the second base to create a second-extended template; h) terminating the reaction by contacting the second-extended template with a terminating composition comprising a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the third base, under conditions effective to produce a nucleic acid product terminating with a trinucleotide sequence complementary to the first, second and third bases; and i) detecting the nucleic acid product under conditions effective to identify a selected trinucleotide sequence in the nucleic acid sample. The methods of di- and tri-nucleotide identification may further be used as methods for sequencing a nucleic acid molecule by identifying selected di- or tri-nucleotide sequences, wherein the identification of the selected di- or tri-nucleotide sequences is followed by the compilation of the identified di- or tri-nucleotide sequences to determine the contiguous nucleic acid sequence of at least a portion of the nucleic acid molecule. The methods of selecting at least a first nucleic acid product terminated with at least a first selected base generally comprise creating a substantially double stranded nucleic acid template comprising at least a first break on at least one strand, and contacting the template with an effective polymerase and a terminating composition comprising at least a first terminating nucleotide, wherein the base of the terminating nucleotide corresponding to the selected base, under conditions effective to produce a nucleic acid product terminated at a selected base, or an effective polymerase and an extending composition under conditions effective to produce a fully extended product only from a template that terminates at the selected base. The methods may first involve creating a substantially double stranded nucleic acid template comprising at least a first random double stranded break. The methods may be further defined as methods for determining the position of at least a first selected dinucleotide sequence of at least a first and at least a second base in at least a first nucleic acid template. The methods may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a 3′ end comprising a hydroxyl group; b) blocking the template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base; c) removing the first blocking composition from contact with the template; d) extending the template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base; e) removing the first extending composition from contact with the template; f) blocking the template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base; g) removing the second blocking composition from contact with the template; h) contacting the template with at least a second extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a dinucleotide sequence complementary to the first and second bases; and i) detecting the nucleic acid product under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid sample. The methods of determining the position of at least a first selected dinucleotide sequence comprising at least a first base and a second base in one or more nucleic acid templates may alternatively comprise: a) attaching a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the template at a temperature effective to disassociate the lower strand of the adaptor; c) annealing a single-stranded oligonucleotide comprising a 3′ hydroxyl group to the template, the first oligonucleotide comprising the same nucleotide sequence as the lower strand plus a first additional 3′ base complementary to the first base and a second additional 3′ base complementary to the second base; d) contacting the template with an extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a dinucleotide sequence complementary to the first and second bases; and e) detecting the nucleic acid product under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid sample. Optionally, the methods of determining the position of at least a first selected dinucleotide sequence comprising at least a first base and a second base in at least a fist nucleic acid template may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the ligated double-stranded nucleic acid segment at a temperature effective to disassociate the lower strand of the adaptor, c) annealing a first single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the first oligonucleotide comprising the same nucleotide sequence as the lower strand; d) blocking the templates by contacting with a first blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the first base; e) removing the first blocking composition from contact with the templates; f) contacting the templates with at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; g) heating the templates at a temperature effective to disassociate the first single stranded oligonucleotide; h) annealing a second single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the first single-stranded oligonucleotide plus a first additional 3′ base complementary to the first base; i) blocking the templates by contacting with a second blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the second base; j) removing the second blocking composition from contact with the templates; k) contacting the templates with the at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; l) heating the templates at a temperature effective to disassociate the second single stranded oligonucleotide; m) annealing a third single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the second single-stranded oligonucleotide plus a second additional 3′ base complementary to the second base; n) contacting the templates with at least a second extending and labeling composition comprising four deoxynucleotide triphosphates, at least one of which comprises a detectable label, under conditions effective to completely extend the non-template strand; o) contacting the templates with at least a first degrading composition under conditions effective to degrade the non-template strands containing a uracil base; and p) detecting the nucleic acid products under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid templates. The methods may also be further defined as methods for determining the position of at least a first selected trinucleotide sequence of at least a first, second and third base in one or more nucleic acid templates. The methods may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a 3′ end comprising a hydroxyl group; b) blocking the template by contacting with a first blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the first base; c) removing the first blocking composition from contact with the template; d) extending the template by contacting with a first extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the first base; e) removing the first extending composition from contact with the template; f) blocking the template by contacting with a second blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the second base; g) removing the second blocking composition from contact with the template; h) extending the template by contacting with a second extending composition comprising an extending deoxynucleotide triphosphate containing the complement of the second base; i) removing the second extending composition from contact with the template; j) blocking the template by contacting with a third blocking composition comprising three dideoxynucleotide triphosphates that do not contain the complement of the third base; k) removing the third blocking composition from contact with the template; l) contacting the template with at least a third extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a trinucleotide sequence complementary to the first, second and third bases; and m) detecting the nucleic acid product under conditions effective to determine the position of the selected dinucleotide sequence in the nucleic acid sample. The methods of determining the position of at least a first selected trinucleotide sequence comprising at least a first base, a second base and a third base in at least a first nucleic acid template may optionally comprise: a) attaching a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the template at a temperature effective to disassociate the lower strand of the adaptor, c) annealing a single-stranded oligonucleotide comprising a 3′ hydroxyl group to the template, the first oligonucleotide comprising the same nucleotide sequence as the lower strand plus a first additional 3′ base complementary to the first base, a second additional 3′ base complementary to the second base and a third additional 3′ base complementary to the third base; d) contacting the template with an extending composition comprising four extending deoxynucleotide triphosphates, at least one of the extending deoxynucleotide triphosphates containing a tagged or labeled base, under conditions effective to produce a fully extended tagged or labeled nucleic acid product with a trinucleotide sequence complementary to the first, second and third bases; and e) detecting the nucleic acid product under conditions effective to determine the position of the selected trinucleotide sequence in the nucleic acid sample. Alternatively, the methods of determining the position of at least a first selected trinucleotide sequence comprising at least a first base, a second base and a third base in one or more nucleic acid templates may comprise: a) ligating a double-stranded nucleic acid segment to the double-stranded break, the double-stranded nucleic acid segment comprising an upper strand comprising a 5′ end comprising a phosphate group and a blocked 3′ end and a lower strand comprising a blocked 5′ end and a blocked 3′ end; b) heating the ligated double-stranded nucleic acid segment at a temperature effective to disassociate the lower strand of the adaptor, c) annealing a first single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the first oligonucleotide comprising the same nucleotide sequence as the lower strand; d) blocking the templates by contacting with a first blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the first base; e) removing the first blocking composition from contact with the templates; f) contacting the templates with at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; g) heating the templates at a temperature effective to disassociate the first single stranded oligonucleotide; h) annealing a second single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the first single-stranded oligonucleotide plus a first additional 3′ base complementary to the first base; i) blocking the templates by contacting with a second blocking composition comprising a dideoxynucleotide triphosphate that contains the complement of the second base; j) removing the second blocking composition from contact with the templates; k) contacting the templates with the at least a first extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; l) heating the templates at a temperature effective to disassociate the second single stranded oligonucleotide; m) annealing a third single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the second single-stranded oligonucleotide plus a second additional 3′ base complementary to the second base; n) contacting the templates with the at least a second extending composition comprising four deoxynucleotide triphosphates, one of the deoxynucleotide triphosphates comprising a uracil base, under conditions effective to completely extend the non-template strand; o) heating the templates at a temperature effective to disassociate the third single stranded oligonucleotide; p) annealing a fourth single-stranded oligonucleotide comprising a 3′ hydroxyl group to the templates, the second oligonucleotide comprising the same nucleotide sequence as the third single-stranded oligonucleotide plus a third additional 3′ base complementary to the third base; q) contacting the templates with at least a third extending and labeling composition comprising four deoxynucleotide triphosphates, at least one of which comprises a detectable label, under conditions effective to completely extend the non-template strand; r) contacting the templates with at least a first degrading composition under conditions effective to degrade the non-template strands containing a uracil base; and s) detecting the nucleic acid products under conditions effective to determine the position of the selected trinucleotide sequence in the nucleic acid templates. Further methods of the present invention are methods of sequencing a nucleic acid molecule by identifying a selected dinucleotide sequence comprising a first base and a second base, the methods comprising: a) creating a substantially double-stranded nucleic acid template comprising a selected dinucleotide sequence on a template strand and comprising an exonuclease-resistant nucleotide in the non-template strand, wherein the base of the exonuclease-resistant nucleotide is complementary to the first base; b) contacting the template with an amount of an exonuclease effective to degrade the non-template strand until the position of the exonuclease-resistant nucleotide; c) removing the exonuclease from contact with the template; d) contacting the template with at least a first terminating composition comprising a tagged or labeled terminating dideoxynucleotide triphosphate containing the complement of the second base, under conditions effective to produce a nucleic acid product terminating with a dinucleotide sequence complementary to the first and second base; and e) detecting the nucleic acid product under conditions effective to identify the selected dinucleotide sequence in the template strand of the nucleic acid template. Detection of a selectively-terminated nucleic acid product or products is also generally integral to the use of the invention in methods for mapping a nucleic acid, wherein the methods generally comprise detecting the nucleic acid product or products under conditions effective to determine the position of the nucleic acid relative to the nucleic acid product or products. The mapping methods may comprise: a) creating a population of substantially double-stranded nucleic acid templates from the nucleic acid, the templates comprising at least a first random break on at least one strand or at least a first random break on only one stand; b) contacting the population of templates with an effective polymerase and at least a first degradable extension-producing composition comprising three non-degradable extending nucleotides (deoxynucleotides) and one degradable nucleotide, under conditions and for a time effective to produce a population of degradable nucleic acid products comprising the degradable nucleotide; c) removing the degradable extension-producing composition from contact with the templates; d) contacting the population of degradable nucleic acid products with an effective polymerase and at least a first nondegradable extending and terminating composition comprising four non-degradable extending deoxynucleotides, at least one of the non-degradable extending deoxynucleotides comprising a detectable label or an isolation tag, under conditions and for a time effective to produce a population of terminated nucleic acid products comprising a degradable region and a nondegradable region; e) contacting the population of terminated nucleic acid products with an effective amount of a degrading composition to degrade the degradable region, thereby producing nested nucleic acid products; and f) detecting the nested nucleic acid products under conditions effective to determine the position of the nucleic acid relative to the nucleic acid product. As used herein, the term “nested nucleic acid products” means a series of nucleic acid products that are a different distance from the point that the nucleic acid synthesis originates. In certain aspects, the products will be overlapping nucleic acid products, but this is not a requirements for most of the embodiments of the present invention. In preferred embodiments, the degradable nucleotide will be a uracil base-containing nucleotide and the degrading composition will comprise a combined effective amount of a uracil DNA glycosylase enzyme and an endonuclease IV or an endonuclease V enzyme. The present invention still further provides methods of sequencing through a telomeric repeat region into a subtelomeric region, comprising: a) providing a substantially double-stranded nucleic acid that comprises, in contiguous sequence order, a terminal single-stranded telomeric overhang, a double-stranded telomeric repeat region and a double-stranded subtelomeric region; b) contacting the nucleic acid with a composition comprising an oligonucleotide or primer that is substantially complementary to and hybridizes to the single-stranded telomeric overhang, an effective polymerase, four extending nucleotides and at least a first tagged or labeled terminating nucleotide under conditions effective to produce a nucleic acid product extended from the primer into the subtelomeric region; and c) detecting the nucleic acid product under conditions effective to determine the nucleic acid sequence of the telomeric overhang, the telomeric repeat region and at least a portion of the subtelomeric region. The present invention also provides a method for determining the percentage of telomeres in a population that contain 3′ overhangs, comprising: a) contacting a telomere-containing nucleic acid sample suspected of having telomeres containing a first, 3′ overhang-containing strand and a second, non-overhang strand, with a composition comprising an oligonucleotide or primer that is substantially complementary to and hybridizes to the single-stranded telomeric overhang, an effective polymerase and four extending nucleotides under conditions effective to produce a nucleic acid product extended from the primer and a trimmed second, non-overhang strand, wherein a telomere that does not have a 3′ overhang will comprise a non-trimmed second, non-overhang strand; and b) detecting the nucleic acid product under conditions effective to determine the amounts of the nucleic acid product, the trimmed second, non-overhang strand, the first, 3′ overhang-containing strand and the non-trimmed second, non-overhang strand. In particular aspects, the amounts of the nucleic acid product, the trimmed second, non-overhang strand, the first, 3′ overhang-containing strand and the non-trimmed second, non-overhang strand are determined by hybridization with labeled G-rich and C-rich telomeric sequences or segments. The term “oligonucleotide”, as used herein, defines a molecule comprised of two or more deoxyribonucleotides or ribonucleotides, usually more than three (3), and typically more than ten (10) and up to one hundred (100) or more. Preferably, “oligos” comprise between about fifteen or twenty and about thirty deoxyribonucleotides or ribonucleotides. Oligonucleotides may be generated in any effective manner, including chemical synthesis, DNA replication, reverse transcription, or a combination thereof. A primer is said to be “substantially” complementary to a strand of specific sequence of a template where it is sufficiently complementary to hybridize to the template sufficient for primer elongation to occur. A primer sequence need not reflect the exact sequence of a template. For example, a non-complementary nucleotide fragment may be attached to the 5′ end of a primer, with the remainder of the primer sequence being substantially complementary to a template. Non-complementary bases or longer sequences can be interspersed into a primer, provided that the primer sequence has sufficient complementarity with the sequence of the template to hybridize and thereby form a template primer complex for synthesis of the extension product of the primer. “Hybridization” methods involve the annealing of a complementary or sufficiently complementary sequence to a target nucleic acid sequence. The ability of two polymers of nucleic acid containing complementary sequences to anneal through base pairing interaction is a well-recognized phenomenon (Marmur and Lane, 1960; Doty et al., 1960). The “complement” of a nucleic acid sequence as used herein refers to an oligonucleotide which, when aligned with the nucleic acid sequence such that the 5′ end of one sequence is paired with the 3′ end of the other, is in “antiparallel association.” Certain bases not commonly found in natural nucleic acids may be included in the nucleic acids of the present invention and include, for example, inosine and 7-deazaguanine. Complementarity need not be perfect; stable duplexes may contain mismatched base pairs or unmatched bases. Those skilled in the art of nucleic acid technology can determine duplex stability empirically considering a number of variables including, for example, the length of the oligonucleotide, base composition and sequence of the oligonucleotide, ionic strength and incidence of mismatched base pairs. Stability of a nucleic acid duplex is measured by the melting temperature, or “T m .” The T m of a particular nucleic acid duplex under specified conditions is the temperature at which on average half of the base pairs have disassociated. The equation for calculating the T m of nucleic acids is well known in the art. As indicated by standard references, an estimate of the T m value may be calculated by the equation: in-line-formulae description="In-line Formulae" end="lead"? T m =81.5° C.+16.6 log M+ 0.41(% GC)−0.61(% form)− 500 /L in-line-formulae description="In-line Formulae" end="tail"? where M is the molarity of monovalent cations, % GC is the percentage of guanosine and cytosine nucleotides in the DNA, % form is the percentage of formamide in the hybridization solution, and L=length of the hybrid in base pairs (Berger and Kimmel, 1987). More sophisticated computations are also known in the art that take structural as well as sequence characteristics into account for the calculation of T m . The invention yet further provides methods of determining the length of a single-stranded overhang of a telomere, comprising contacting a telomere comprising a single-stranded overhang with an excess of a primer that hybridizes to the single-stranded overhang under conditions effective to allow hybridization of substantially complementary nucleic acids, and quantitating the primers thus hybridized to the single-stranded overhang. These methods may further comprise contacting the primers hybridized to the single-stranded overhang with a ligation composition in an amount and for a time effective to ligate the primers, wherein the length of the ligated primers is quantitated. | 20040713 | 20070918 | 20050310 | 64124.0 | 0 | KIM, YOUNG J | COMPOSITIONS AND METHODS FOR ANALYSIS OF NUCLEIC ACIDS | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,890,510 | ACCEPTED | Antenna and frequency diversity receiving apparatus | To adjust an antenna and frequency diversity receiving apparatus comprising n antennas (A1-An) and using m receiving frequencies to the best antenna frequency combination each of the n antennas (A1-An) there is assigned an IF stage (Z1-Zn). A quality signal (Q1-Qnm) representing the receiving quality will be generated for each of the n×m possible antenna frequency combinations within the IF stages (Z1-Zn). A digital signal processor (DS) determines by comparing the best antenna frequency combination out of the n×m quality signals (Q1-Qnm). The selected antenna (A1) will be switched to the digital signal processor (DS) via a multiplex switch (M), and the assigned IF stage (Z1) is tuned to the determined receiving frequency. | 1. Method for selecting one of n antennas (A1-An) and one of m alternative receiving frequencies in an antenna and frequency diversity receiving apparatus, characterized in that all n×m possible antenna frequency combinations are set to determine the receiving quality of each of the n×m possible antenna frequency combinations, in that the n×m determined receiving qualities are compared one to another, and in that the antenna frequency combination with the best receiving quality will be selected. 2. Method for selecting one of n antennas (A1-An) and one of m alternative receiving frequencies in an antenna and frequency diversity receiving apparatus, characterized in that a plurality of n×m possible antenna frequency combinations are set to determine the receiving quality of each of the n×m possible antenna frequency combinations, in that receiving qualities of possible antenna frequency combinations which have not been determined are calculated, especially interpolated, in that the determined and calculated receiving qualities are compared one to another, and in that the antenna frequency combination with the best receiving quality will be selected. 3. Method according to claim 1, characterized in that to each antenna (A1-An) there will be assigned an IF stage (Z1-Zn), in that each IF stage (Z1-Zn) generates an IF signal (ZF1-ZFn) out of the antenna signal of the antenna (A1-An) connected to it, in that each IF stage (Z1-Zn) generates a quality signal (Q1-Qnm) representing the receiving quality out of the antenna signal of the antenna (A1-An) connected to it, in that within a digital signal processor (DS) there are compared each to another and analyzed the n×m quality signals (Q1-Qnm) representing the receiving quality, in that the digital signal processor (DS) ascertains the antenna frequency combination having the best receiving quality out of the n×m quality signals (Q1-Qnm) representing the receiving qualities, in that the digital signal processor (DS) connects the output of the IF stage (Z1) delivering the best receiving quality via a switch (M), especially a multiplex switch (M) with the input of an analog-to-digital converter (AD) a digital output signal of which will be supplied to the input of the digital signal processor (DS), and in that the signal at the output of digital signal processor (DS) will be supplied to a demodulator (DM). 4. Method according to claim 3, characterized in that the IF signals (ZF1-ZFn) are digitalized. 5. Method of claims 3, characterized in that for each IF stage (Z1-Zn) there is provided a mixer, a phase loop control circuit and a mixer oscillator. 6. Method of claim 3, characterized in that the IF stages (Z1-Zn) are built as integrated circuit. 7. Method of claim 1, characterized in that the values of the receiving qualities are digitalized as quality signals (Q1-Qnm). 8. Antenna and frequency diversity receiving apparatus for selecting one of n antennas (A1-An) and one of m alternative receiving frequencies, characterized in that each of the n antennas (A1-An) is connected to the input of an IF stage (Z1-Zn) assigned to it, in that the IF outputs (ZF1-ZFn) of the n IF stages (Z1-Zn) are connected with the n inputs of a switch, especially a multiplex switch (M) the output of which is connected with the input of an analog-to-digital converter (AD), in that the output of the analog-to-digital converter (AD) is connected with the input of a digital signal processor (DS) to the output of which there is connected a demodulator (DM), in that there is provided at each IF stage (Z1-Zn) a quality output, at which a quality signal (Q1-Qnm) representing the receiving quality is retrievable, in that the quality outputs of the n IF stages (Z1-Zn) are connected with n quality inputs of the digital signal processor (DS), in that at least one control output (F1-Fn) of the digital signal processor (DS) is coupled with each one control input of the n IF stages (Z1-Zn) for setting the receiving frequency, and in that a switch output of the digital signal processor (DS) is connected with the control input of the multiplex switch (M). 9. Antenna and frequency diversity receiving apparatus according to claim 8, characterized in that a control output (F) of the digital signal processor (DS) is coupled with each one of the control inputs of the n IF stages (Z1-Zn) via a frequency control means (FS, FC) for setting the corresponding receiving frequency. 10. Antenna and frequency diversity receiving apparatus according to claim 8, characterized in that the digital signal processor (DS) provides each one control output (F1-Fn) coupled with a corresponding control input of each one of the n IF stages (Z1-Zn) for setting the receiving frequency. 11. Antenna and frequency diversity receiving apparatus of claim 8, characterized in that in each IF stage (Z1-Zn) there is provided a mixer, a phase loop control circuit and a mixer oscillator. 12. Antenna and frequency diversity receiving apparatus according to claim 11, characterized in that the IF stages (Z1-Zn) are integrated in a module. 13. Antenna and frequency diversity receiving apparatus of claim 8, characterized in that within a module there are integrated the IF stages (Z1-Zn), the multiplex switch (M), the analog-to-digital converter (AD), the digital signal processor (DS), and the demodulator (DM). | Method for selecting one of n antennas and one of m alternative receiving frequencies in an antenna and frequency diversity receiving apparatus as well as antenna and frequency diversity receiving apparatus The invention regards to a method for selecting one of n antennas and one of m alternative receiving frequencies in an antenna and frequency diversity receiving apparatus. Further, the invention regards to an antenna and frequency diversity receiving apparatus for selecting one of n antennas and one of m alternative receiving frequencies. An antenna and frequency diversity receiving apparatus is a radio receiving apparatus having a radio receiver being connectable to one of several, most specially separated antennas and being tuneable to one of several alternative receiving frequencies. Antenna and frequency diversity receiving apparatuss are put to use e. g. in motor vehicles. Window antennas are preferably used as antennas, which are integrated e. g. in the windows of the motor vehicles. A selection circuit selects according to prescribable criteria one of the antennas to be connected to the radio receiver in operation of the antenna and frequency diversity receiving apparatus, for example a radio broadcasting apparatus, a television brosdcasting apparatus or a telephone equipment. An evaluation means selects one of the alternative receiving frequencies to which the radio receiver will be tuned. In order to get best possible reception, it is necessary, to find the best antenna frequency combination. Therefore, it is an object of the invention, to create a method for an antenna and frequency diversity receiving apparatus as well as an antenna and frequency diversity receiving apparatus in such a way that the best antenna frequency combination will be as quickly and reliably as possible found out of the antennas of the receiving apparatus and of the receiving frequencies being available. This object will be solved procedural with features given in claim 1 or 2, especially by setting all n×m possible antenna frequency combinations, to determine the receiving quality of each of the n×m possible antenna frequency combinations, by comparing the n×m determined receiving qualities against one another, and by selecting the one antenna frequency combination having the best receiving quality. This object will be solved regarding an apparatus by features given in claim 7, especially in such a way, that each of the n antennas is connected to the input of an IF (Intermediate Frequency) stage assigned to it, in that the IF output of the n IF stages are connected with the n inputs of a multiples switch, the output of which is connected with the input of an analog-to-digital converter, in that the output of the analog-to-digital converter is connected with the input of a digital signal processor, the output of which is connected to a demodulator, in that each IF stage provides a quality output at which a quality signal representing the receiving quality can be tapped, in that the quality outputs of the n IF stages are connected with n quality inputs of the digital signal processor, in that each one controlling output of the digital signal processor is connected to each one controlling input of the n IF stages for setting the receiving frequency, and in that a controlling output of the digital signal processor is connected with the controlling input of the multiplex switch. The inventive method provides that the receiving quality can be measured of each antenna in combination with each of the m available receiving frequencies in an antenna and frequency diversity receiving apparatus having n antennas. Therefore, all n×m possible antenna frequency combinations are provided and the receiving quality will be determined for each of these combinations. The one antenna frequency combination will be adjusted, which provides the best receiving quality. An embodiment of the invention provides an IF stage for each antenna. The outputs of the IF stages are connected to the inputs of a multiplex switch, the output of which is connected to the input of an analog-to-digital converter. The output of the analog-to-digital converter is connected with the input of a digital signal processor, to the output of which there is connected a demodulator. For example the demodulator can be integrated in the digital signal processor, too. Each of the n IF stages will be tuned to each of the receiving frequencies. The receiving quality will be determined for each receiving frequency and will be analysed in the digital signal processor determining the antenna frequency combination having the best receiving quality. The digital signal processor switches the antenna found to the input of the analog-to-digital converter via the multiplex switch and tunes the corresponding IF stage to the receiving frequency found. The inventive method and the inventive antenna and frequency diversity receiving apparatus are described and explained in more detail by way of embodiments shown in the figures. According to FIG. 1 each of the n antennas A1-An is connected to the input of an If stage Z1-Zn assigned to it. The outputs of the n IF stages Z1-Zn are connected with the inputs of a multiplex switch M, the output of which has been connected with the input of an analog-to-digital converter AD. The output of the analog-to-digital converter AD is connected with the input of a digital signal processor DS, to the output of which is connected a demodulator DM. At each IF stage Z1-Zn there is provided a quality output, at which a quality signal Q1-Qn can be tapped, representing a degree of the receiving quality. These quality outputs of the IF stages Z1-Zn are connected to quality inputs of the digital signal processor DS. The n frequency outputs F1-Fn of the digital signal processor DS are connected with the tuning inputs of the IF stages. The switch output of the digital signal processor DS is connected with the controlling input of the multiplex switch M. The digital signal processor DS tunes each of the n IF stages Z1-Zn to each of the m alternative receiving frequencies, that all n×m antenna frequency combinations are provided. Each IF stage Z1-Zn produces a quality signal Q1-Qnm for each of the m alternative receiving frequencies. Therefore, n×m quality signals Q1-Qnm are generated, the quality signals being compared with each other and analysed in the digital signal processor. The digital signal processor ascertains with the help of the n×m quality signals Q1-Qnm the one antenna frequency combination, which provides the best receiving quality. The digital signal processor switches the multiplex switch M to the found antenna, e. g. the antenna A1, and tunes the corresponding IF stage, e. g. the IF stage Z1, to the receiving frequency found. Therefore, the digital signal processor DS receives its receiving signal from the one antenna frequency combination, distinguished by the best receiving quality among all possible antenna frequency combinations. A feedback of the IF signals is not necessary, because the receiving quality will be ascertained already in the IF stages Z1-Zn. The best receiving frequency can be ascertained e. g. in well known manner by quality evaluation of the IF signal for the different alternative receiving frequencies. The digital processing of the IF signal within the digital signal processor DS provides the advantage that the generating of a retuning signal will be comparatively easy. Furthermore, interferences caused by retuning operations can be suppressed or resampled in an easy manner. Within each IF stage Z1-Zn there is provided a mixer, a phase loop control circuit and a mixer oscillator. The IF stages are integrateable in a module as integrated circuits in a preferred manner. Preferably, the IF stages Z1-Zn, the multiplex switch M, the analog-to-digital converter AD, the digital signal processor DS and the demodulator DM are integrated in a single module. A further advantage of the invention can be gathered in the fact that a receiver comprising a receiving antenna can be expanded to the inventive antenna and frequency diversity receiving apparatus in a simple manner. FIG. 2 shows an second embodiment. Elements shown and described in FIG. 1 are like in FIG. 1 and without new description. In the main, only different elements are described in the following. According to one aspect of this second embodiment quality signals Q1, Q2 . . . Qn are set to the digital signal processor DS via a quality signal switch QM coupling in each moment one of the quality signals Q1, Q2 . . . Qn as a quality signal Q to the digital signal processor DS. The digital signal processor DS controls quality signal switch QM via a control signal QC coupled from an quality signal control output to quality signal switch QM. Therefore, it is not necessary to provide a digital signal processor DS comprising n quality signal inputs but only one quality signal input. According to another aspect of this second embodiment there is coupled only one frequency output F via a frequency switch FS to the frequency inputs F1, F2 . . . Fn of the individual IF stages Z1, Z2 . . . Zn. To control the frequency switch FS the digital signal processor DS provides a frequency control signal via a frequency control output F to a frequency switch control input. According to a preferred embodiment each IF stage Z1, Z2, . . . Zn comprises an IF stage memory ZM for storing among others the frequency to be used by the corresponding IF stage until receipt of another frequency value via frequency switch FS. Therefore, it is possible to use a frequency value determined as best frequency value at an earlier determining cycle. According to another embodiment, not shown in FIG. 2, frequency switch could be replaced by an frequency splitter splitting frequency output line F to a plurality of frequency lines F1, F2 . . . Fn connecting one output F of the digital signal processor DS with the frequency inputs of all IF stages. According to this embodiment the digital signal processor DS provides all IF stages at one moment with the same frequency F. Therefore, antenna and frequency diversity receiving apparatus provides a digital signal processor having a frequency control output which is coupled with each one of the control inputs of the n IF stages Z1-Zn via a plurality of n frequency outputs at the digital single processor DS or, alternatively, via only one frequency output of the digital signal processor DS and in addition a frequency control means FS. Frequency control means could be frequency switch FS of FIG. 2 or only a simple line splitter. First embodiment describes a method and apparatus providing a digital signal processor comprising n frequency outputs to supply the n IF stages with each one frequency value or frequency signal. Within m steps every IF stage will be provided with the m possible frequency values to determine m quality values Q1 . . . Q1m, . . . , Qn . . . Qnm quality signals Q1, . . . Qnm. According to another embodiment it would be also possible, to provide all or individual IF stages Z1, . . . Zn with only some of all possible frequency values. Accordingly, only corresponding quality signals would be determined. To get same number of n×m quality signals or values of such quality signals it would be possible to calculate missing values e. g. by interpolating. List of Reference Numbers: AD analog-to-digital converter A1-An antenna DM demodulator DS digital signal processor F1-Fn frequency output M multiplex switch Q1-Qnm quality signal ZF1-ZFn IF signal Z1-Zn IF stage | 20040712 | 20071002 | 20050310 | 94763.0 | 0 | NGUYEN, DUC M | ANTENNA AND FREQUENCY DIVERSITY RECEIVING APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,517 | ACCEPTED | Original reading device | An original reading device includes a registration roller located upstream of an original reading position in an original transport path for adjusting the timing of feeding an original to the original reading position. There is at least one original feed roller for transporting the original which has been fed from an original loading tray into the original transport path toward the registration roller. A rotary motion controller is also provided, and it causes the original feed roller closest to the registration roller to rotate when a rear part of the original close to a trailing edge thereof passes over the original feed roller closest to the registration roller. | 1. An original reading device comprising: an original transport path formed from an original loading tray to an original output position by way of an original reading position; a registration roller located upstream of the original reading position along an original feeding direction for adjusting the timing of feeding an original to the original reading position; at least one original feed roller for transporting the original which has been fed from the original loading tray into the original transport path toward the registration roller; and a rotary motion controller which causes said at least one original feed roller to stop after a leading edge of the original has come into contact with the registration roller and causes the original feed roller closest to the registration roller to rotate when a rear part of the original close to a trailing edge thereof passes over the original feed roller closest to the registration roller. 2. The original reading device according to claim 1, wherein the rotary motion controller causes the original feed roller closest to the registration roller to rotate since the rear part of the original close to the trailing edge thereof is brought to the original feed roller closest to the registration roller until the trailing edge of the original leaves the original feed roller closest to the registration roller. 3. The original reading device according to claim 1 further comprising: a pickup roller for feeding each original from the original loading tray into the original transport path; wherein a driving force is transmitted from the original feed roller to the pickup roller, and the pickup roller feeds a next original when the rear part of the preceding original passes over the original feed roller. 4. The original reading device according to claim 1, wherein the circumferential speed of the original feed roller closest to the registration roller is higher than the circumferential speed of the registration roller. 5. The original reading device according to claim 1 further comprising: an original size sensor for detecting the size of the original loaded on the original loading tray; and a timer for measuring time elapsed since the registration roller has begun to rotate; wherein the rotary motion controller determines the timing of rotating the original feed roller closest to the registration roller based on the elapsed time measured by the timer and the length of the original along the original feeding direction. | CROSS REFERENCE This Nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2003-274727 filed in Japan on Jul. 15, 2003, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION The present invention relates to an original reading device for reading image information on an original. More particularly, the invention pertains to a original reading device having an automatic document feeding function. One known method of reading an original used in an original reading device is an original moving method in which image information on the original is read as the original is fed through an original transport path. The original moving method, widely used in the original reading device in recent years, has an advantage that a plurality of originals loaded on a document tray can be automatically transported to an original reading position and read one after another. The original moving method, however, has a problem that if unevenness in original transport speed occurs at the original reading position, this unevenness in the original transport speed results in irregularities in a read image. It is therefore important for the original reading device employing the original moving method to ensure that the original transport speed does not become uneven at the original reading position. One example of a prior art arrangement for the solution of this problem is shown in Japanese Laid-open Patent Application No. H04-7237. A document feeder described in this Patent Application includes a transport roller located tight against an original reading portion with an original transport path formed between the original reading portion and the transport roller. The transport roller feeds an original downstream along the original transport path while pressing the original against the original reading portion at the original reading position. The document feeder of Japanese Laid-open Patent Application No. H04-7237 includes a pair of rotary motion transmission mechanisms provided at both axial ends of the transport roller, each rotary motion transmission mechanism including an untoothed pulley and an untoothed belt. Since the untoothed belt of each rotary motion transmission mechanism properly slips over the untoothed pulley, the rotary motion transmission mechanisms located at both axial ends of the transport roller are not likely to produce a phase lag. For this reason, it is generally appreciated that the document feeder of this Patent Application is unlikely to produce unevenness in original transport speed. However, the aforementioned arrangement of the document feeder of Japanese Laid-open Patent Application No. H04-7237 does not take into consideration unevenness in the original transport speed occurring at the original reading position due to a relation between the transport roller and an original feed roller. A main factor that causes this unevenness in the original transport speed is a load fluctuation which occurs when a trailing edge of the original passes beyond the original feed roller. Since this load fluctuation is not taken into consideration in the design of conventional document feeders, there is a risk of degradation of original reading accuracy due to the unevenness in the original transport speed at the original reading position. SUMMARY OF THE INVENTION It is an object of the invention to provide an original reading device which can reduce the risk of the occurrence of unevenness in original transport speed at an original reading position with a simple construction. To achieve this object, an original reading device of the invention includes an original transport path, a registration roller, an original feed roller and a rotary motion controller. Unevenness in original transport speed is likely to occur if a load fluctuation occurs when a trailing edge of an original being transported along the original transport path passes beyond the original feed roller. The load fluctuation is apt to occur when a rear part of the original close to the trailing edge thereof secured by the original feed roller is released. This load fluctuation is most likely to occur if a tensile force is exerted on the original when the rear part of the original is released. In the original reading device of the invention, the rotary motion controller causes the original feed roller to rotate when the rear part of the original passes over the original feed roller. When the original feed roller rotates in this way, the rear part of the original is pushed downstream in an original feeding direction. Consequently, the tensile force exerted on the original relieved. If the circumferential speed of the original feed roller is higher than the circumferential speed of the registration roller, the original properly slacks before the rear part of the original passes beyond the original feed roller. If the original properly slacks in this way, the original becomes less susceptible to the load fluctuation when the rear part of the original is released and, as a consequence, the unevenness in the original transport speed becomes less likely to occur. These and other objects, features and advantages of the invention will become more apparent upon reading the following detailed description along with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing the construction of an original reading device according to a preferred embodiment of the invention; FIG. 2 is a block diagram showing the configuration of principal parts of the original reading device of FIG. 1; FIG. 3 is a diagram showing how an original is transported in the original reading device; FIG. 4 is a diagram showing how the original is transported in the original reading device; FIG. 5 is a diagram showing how multiple originals are transported one after another in the original reading device; and FIGS. 6A and 6B are diagrams showing a separation roller and a nearby structure thereof. DETAILED DESCRIPTION OF THE INVENTION An original reading device 1 having an automatic document feeding function according to a specific embodiment of the invention is now described with reference to the accompanying drawings. FIG. 1 is a diagram showing the construction of the original reading device 1 according to the embodiment of the invention. The original reading device 1 includes platen glass plates 2A and 2B. The original reading device 1 is roughly divided into two sections. These are an automatic document feeder 20 located above the platen glass plates 2A, 2B and an optical scanning system 10 located beneath the platen glass plates 2A, 2B. The optical scanning system 10 includes a light source 11, mirrors 12, 13, 14, an optical lens 15 and a charge-coupled device (CCD) 16. The light source 11 projects light on an original and the mirrors 12, 13, 14 guide the light reflected by the original to the optical lens 15 which focuses the reflected light on the CCD 16. The CCD 16 is a photoelectric converting device which converts incident light into an electric signal. The automatic document feeder 20 itself serves as an original cover for covering and uncovering the platen glass plates 2A, 2B. The automatic document feeder 20 includes an original loading tray 33 on which originals are loaded and an original output tray 31 on which each original which has undergone an image reading process is discharged from an original transport path 25. The original transport path 25 is formed between the original loading tray 33 and the original output tray 31 by way of an original reading position. The automatic document feeder 20 further includes a pickup roller 21, a separation roller 22, a pair of registration rollers 26, a pair of transport rollers 28 and a pair of discharge rollers 32. These rollers are disposed along the original transport path 25 from upstream side to downstream side thereof as illustrated in FIG. 1. In this embodiment, the original reading position is situated in that part of the original transport path 25 which faces the platen glass plate 2B. There is provided a separation plate 23 disposed face to face with the separation roller 22 on an opposite side of the original transport path 25. There is provided a transported original sensor 24 for detecting each original being transported between the separation roller 22 and the registration rollers 26 along the original transport path 25. On an opposite side of the platen glass plate 2B with respect to the original transport path 25, there is also provided an original holder 27 for pressing the original which is undergoing the image reading process against the platen glass plate 2B. The discharge rollers 32 are located at a downstream end of the original transport path 25 as shown in FIG. 1. Close to the discharge rollers 32, there is provided a flapper 29 for selectively guiding the original being ejected through the discharge rollers 32 onto an intermediate tray 30 or onto the original output tray 31. FIG. 2 is a block diagram showing the configuration of principal parts of the original reading device 1. As shown in FIG. 2, the original reading device 1 includes a central processing unit (CPU) 50, a read-only memory (ROM) 51, a random-access memory (RAM) 52, an original size sensor 55, a driving motor 54, clutches 58 and 59, a driver 53, and drivers 56 and 57. The ROM 51 stores a program necessary for operating the original reading device 1 according to a prescribed operating sequence. The RAM 52 is a volatile memory used for temporary data storage. The original size sensor 55 is disposed on the original loading tray 33 for detecting the size of the original. The driving motor 54 works as a prime mover which produces and transmits a rotational driving force to the separation roller 22 and the registration rollers 26. In this embodiment, the separation roller 22 serves as an original feed roller for feeding each original into the original transport path 25. It is to be noted, however, that the original feed roller is not necessarily limited to the separation roller 22 according to the invention. If there is provided another roller (or roller pair) for feeding each original between the separation roller 22 and the registration rollers 26, for example, this roller (roller pair) disposed along the original transport path 25 upstream of the registration rollers 26 is also an original feed roller (roller pair). The clutch 58 is disposed on a driving force transmitting route through which the driving force of the driving motor 54 is transmitted to the separation roller 22. The clutch 59 is disposed on a driving force transmitting route through which the driving force of the driving motor 54 is transmitted to the registration rollers 26. The driver 53 drives the driving motor 54 according to an instruction fed from the CPU 50. The driver 56 engages and disengages the clutch 58 according to an instruction fed from the CPU 50. The driver 57 engages and disengages the clutch 59 according to an instruction fed from the CPU 50. Working in accordance with the program stored in the ROM 51, the CPU 50 controls the individual parts of the original reading device 1 in a centralized fashion. Specifically, the CPU 50 outputs specific signals to the drivers 53, 56, 57 to cause the drivers 53, 56, 57 to operate. More specifically, the CPU 50 controls the operation of the driving motor 54, the original feed roller and the registration rollers 26 through the drivers 53, 56, 57. In this embodiment, the CPU 50 constitutes a rotary motion controller of the invention. The CPU 50 includes an internal timer 50A for counting time. Using this timer 50A, the CPU 50 measured time elapsed from the beginning of a specific action. FIG. 3 is a diagram showing how each original is transported in the original reading device 1. Each sheet of originals stacked on the original loading tray 33 is pulled out from the original loading tray 33 by the pickup roller 21. Even if the pickup roller 21 pulls out more than one sheet from the original loading tray 33, only a single original P1 is fed into the original transport path 25 at a time as the separation roller 22 and the separation plate 23 located downstream of the pickup roller 21 prevent more than one sheet from being fed at a time. As the original P1 is transported along the original transport path 25 in an original feeding direction, the transported original sensor 24 detects a leading edge and a trailing edge of the original P1. Rotary motion of the separation roller 22 stops after the leading edge of the original P1 transported downstream in the original feeding direction has come into contact with the registration rollers 26. This means that the original P1 is once stopped before the original P1 is advanced to the original reading position. More specifically, the CPU 50 causes the separation roller 22 to stop a specific period of time after the transported original sensor 24 has detected the leading edge of the original P1. The original P1 is kept in a standby state with the leading edge of the original P1 held in contact with the registration rollers 26 in this fashion and the registration rollers 26 are caused to rotate with specific timing to adjust the timing of guiding the original P1 to the original reading position. When the timing of guiding the original P1 to the original reading position is reached, the CPU 50 causes the registration rollers 26 to rotate so that the original P1 is advanced to the original reading position. The moment the CPU 50 causes the registration rollers 26 to rotate, the CPU 50 causes the internal timer 50A thereof to start counting the time. The original P1 passes over the original reading position while being pressed by the original holder 27 against the platen glass plate 2B. The optical scanning system 10 reads image information on the original P1 while the original P1 passes over the original reading position. When the registration rollers 26 begin to advance the original P1 sandwiched therebetween, the clutch 58 is in a disengaged state, so that the rotational driving force of the driving motor 54 is not transmitted to the separation roller 22. FIG. 4 is a diagram showing a situation in which the trailing edge of the original P1 has just passed a point between the separation roller 22 and the separation plate 23. Until the trailing edge of the original P1 passes between the separation roller 22 and the separation plate 23, a tensile force occurs in the original P1. This tensile force occurs as a forward part (close to the leading edge) of the original P1 is pulled downstream in the original feeding direction by the registration rollers 26 while a rear part of the original P1 close to the trailing edge thereof is gripped between the separation roller 22 and the separation plate 23. When the trailing edge of the original P1 passes between the separation roller 22 and the separation plate 23, the rear part of the original P1 gripped between the separation roller 22 and the separation plate 23 is released. In the earlier-mentioned original reading device (document feeder), a load fluctuation occurs when the rear part of the original is released and, as a consequence, unevenness occurs in the original transport speed as the original passes over the original reading position. This unevenness (or change) in original transport speed occurring during the image reading process is apt to result in deterioration in the image reading performance of the original reading device. In the original reading device 1 of this embodiment, the CPU 50 causes the separation roller 22 to rotate immediately before the trailing edge of the original P1 passes between the separation roller 22 and the separation plate 23. If the separation roller 22 rotates, the tensile force acting in a portion of the original P1 between the separation roller 22 and the registration rollers 26 decreases. If the circumferential speed of the separation roller 22 is made higher than the circumferential speed of the registration rollers 26 at this time, the portion of the original P1 between the separation roller 22 and the registration rollers 26 properly slacks. As a result, the load fluctuation which would occur when the trailing edge of the original P1 passes the point between the separation roller 22 and the separation plate 23 decreases and the unevenness in original transport speed becomes less likely to occur at the original reading position. The timing at which the trailing edge of the original P1 passes the point between the separation roller 22 and the separation plate 23 is calculated based on an elapsed time from the beginning of rotation of the registration rollers 26, the size of the original P1 and the original transport speed which is uniquely determined in the original reading device 1. In calculating this timing, the CPU 50 measures the elapsed time from the beginning of rotation of the registration rollers 26 by using the internal timer 50A. The size of the original P1 is detected by the original size sensor 55 located on the original loading tray 33. Data on the original transport speed is stored in the ROM 51. Upon calculating the timing at which the trailing edge of the original P1 passes the point between the separation roller 22 and the separation plate 23, the CPU 50 engages the clutch 58 to rotate the separation roller 22 at a slightly advanced timing than the calculated timing. It is therefore possible to cause the separation roller 22 to begin rotating when the rear part of the original P1 close to the trailing edge thereof is located between the separation roller 22 and the separation plate 23, so that the trailing edge of the original P1 moves downstream in the original feeding direction. Here, if the timing at which the separation roller 22 is caused to begin rotating is advanced, the original P1 will produce a larger slack (loose part). If the timing at which the separation roller 22 is caused to begin rotating is delayed, on the contrary, the original P1 will produce a smaller slack. If the slack in the original P1 is too large, the original P1 being transported is likely to jam in the original transport path 25. If the slack in the original P1 is too small, the load fluctuation will occur when the trailing edge of the original P1 passes between the separation roller 22 and the separation plate 23. In this embodiment, the CPU 50 controls rotation of the separation roller 22 in such a manner that the separation roller 22 begins to rotate when a position of the original P1 located 5 mm to 10 mm forward from the trailing edge thereof passes by the separation roller 22 so that the original P1 would slack by a proper amount. In this embodiment, a mechanism for rotating the separation roller 22 and the registration rollers 26 is set to such a gear ratio that the circumferential speed of the separation roller 22 is higher than the circumferential speed of the registration rollers 26 by approximately 0.5% to 1.0%. This difference in the circumferential speed makes it easy to produce a proper slack in the original P1 between the separation roller 22 and the registration rollers 26 by rotating the separation roller 22. In this embodiment, the CPU 50 keeps the separation roller 22 rotating since the rear part of the original P1 close to the trailing edge thereof is brought to the point between the separation roller 22 and the separation plate 23 until the trailing edge of the original P1 completely passes between the separation roller 22 and the separation plate 23. The CPU 50 controls the separation roller 22 in this way to ensure that an adequate slack would be formed in the original P1. FIG. 5 is a diagram showing how multiple originals are transported in succession in the original reading device 1. As previously mentioned, the separation roller 22 is caused to rotate immediately before the trailing edge of the original P1 passes between the separation roller 22 and the separation plate 23 in the image reading process. At this time, the rotational driving force exerted on the separation roller 22 is transmitted to the pickup roller 21 via an unillustrated belt. Also, the rotational driving force exerted on the separation roller 22 is transmitted to an arm of the pickup roller 21 via the belt, causing the arm to swing. This arrangement makes it possible to begin transporting an original P2 to be fed next at the timing when the separation roller 22 begins to rotate. FIG. 5 shows a situation in which a leading edge of the original P2 is brought to the point between the separation roller 22 and the separation plate 23 approximately at the same time when the trailing edge of the original P1 comes apart from the separation roller 22. FIGS. 6A and 6B are enlarged views particularly showing the point between the separation roller 22 and the separation plate 23. Of these Figures, FIG. 6A shows an ordinary original transporting state whereas FIG. 6B shows an original transporting state in which the original reading device 1 is transporting the multiple originals in succession. As can be seen from FIG. 6B, the original reading device 1 guides the leading edge of the original P2 to the point between the separation roller 22 and the separation plate 23 approximately at the same time when the separation roller 22 pushes the trailing edge of the original P1 downstream in the original feeding direction. As the successive originals are fed in this fashion, the distance between the two originals P1, P2 is so small that images on the multiple originals can be read at a high reading speed. While the invention has thus far been described with reference to the preferred embodiment thereof, the aforementioned arrangements of the embodiment are simply illustrative and not limiting the invention. The scope of the invention should be determined solely by the appended claims, and not by the foregoing embodiment. It is to be understood that the invention is intended to cover the appended claims as well as all possible modifications of the embodiment and equivalents thereof which may occur to those skilled in the art within the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to an original reading device for reading image information on an original. More particularly, the invention pertains to a original reading device having an automatic document feeding function. One known method of reading an original used in an original reading device is an original moving method in which image information on the original is read as the original is fed through an original transport path. The original moving method, widely used in the original reading device in recent years, has an advantage that a plurality of originals loaded on a document tray can be automatically transported to an original reading position and read one after another. The original moving method, however, has a problem that if unevenness in original transport speed occurs at the original reading position, this unevenness in the original transport speed results in irregularities in a read image. It is therefore important for the original reading device employing the original moving method to ensure that the original transport speed does not become uneven at the original reading position. One example of a prior art arrangement for the solution of this problem is shown in Japanese Laid-open Patent Application No. H04-7237. A document feeder described in this Patent Application includes a transport roller located tight against an original reading portion with an original transport path formed between the original reading portion and the transport roller. The transport roller feeds an original downstream along the original transport path while pressing the original against the original reading portion at the original reading position. The document feeder of Japanese Laid-open Patent Application No. H04-7237 includes a pair of rotary motion transmission mechanisms provided at both axial ends of the transport roller, each rotary motion transmission mechanism including an untoothed pulley and an untoothed belt. Since the untoothed belt of each rotary motion transmission mechanism properly slips over the untoothed pulley, the rotary motion transmission mechanisms located at both axial ends of the transport roller are not likely to produce a phase lag. For this reason, it is generally appreciated that the document feeder of this Patent Application is unlikely to produce unevenness in original transport speed. However, the aforementioned arrangement of the document feeder of Japanese Laid-open Patent Application No. H04-7237 does not take into consideration unevenness in the original transport speed occurring at the original reading position due to a relation between the transport roller and an original feed roller. A main factor that causes this unevenness in the original transport speed is a load fluctuation which occurs when a trailing edge of the original passes beyond the original feed roller. Since this load fluctuation is not taken into consideration in the design of conventional document feeders, there is a risk of degradation of original reading accuracy due to the unevenness in the original transport speed at the original reading position. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the invention to provide an original reading device which can reduce the risk of the occurrence of unevenness in original transport speed at an original reading position with a simple construction. To achieve this object, an original reading device of the invention includes an original transport path, a registration roller, an original feed roller and a rotary motion controller. Unevenness in original transport speed is likely to occur if a load fluctuation occurs when a trailing edge of an original being transported along the original transport path passes beyond the original feed roller. The load fluctuation is apt to occur when a rear part of the original close to the trailing edge thereof secured by the original feed roller is released. This load fluctuation is most likely to occur if a tensile force is exerted on the original when the rear part of the original is released. In the original reading device of the invention, the rotary motion controller causes the original feed roller to rotate when the rear part of the original passes over the original feed roller. When the original feed roller rotates in this way, the rear part of the original is pushed downstream in an original feeding direction. Consequently, the tensile force exerted on the original relieved. If the circumferential speed of the original feed roller is higher than the circumferential speed of the registration roller, the original properly slacks before the rear part of the original passes beyond the original feed roller. If the original properly slacks in this way, the original becomes less susceptible to the load fluctuation when the rear part of the original is released and, as a consequence, the unevenness in the original transport speed becomes less likely to occur. These and other objects, features and advantages of the invention will become more apparent upon reading the following detailed description along with the accompanying drawings. | 20040714 | 20080122 | 20050120 | 67383.0 | 0 | MCCLAIN, GERALD | ORIGINAL READING DEVICE WITH CONTROLLER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,527 | ACCEPTED | Drive for system for processing fiber optic connectors | An apparatus for moving a fiber including a plurality of fiber optic connectors through a system for processing the plurality of fiber optic connectors. The apparatus can include a first drive mechanism for moving the fiber through the system, such as a cart and a conveyor. The apparatus can include a second drive mechanism for moving the plurality of fiber optic connectors through the system, such as a screw drive. The apparatus can also include a controller for coordinating movement of the first drive mechanism with the second drive mechanism. | 1. An apparatus for moving a fiber including a plurality of fiber optic connectors through a system for processing the plurality of fiber optic connectors, the apparatus comprising: a first drive mechanism for moving the fiber through the system; a second drive mechanism for moving the plurality of fiber optic connectors through the system; and a controller for coordinating movement of the first drive mechanism with the second drive mechanism. 2. The apparatus of claim 1, wherein the first drive mechanism includes: a cart including a platform for holding a spool including the fiber; and a cart drive for moving the cart and associated fiber through the system. 3. The apparatus of claim 2, wherein the first drive mechanism further includes a track along which the cart is moved. 4. The apparatus of claim 3, wherein the cart drive is a walking beam drive. 5. The apparatus of claim 1, wherein the second drive mechanism includes a screw drive for moving the plurality of fiber optic connectors through the system. 6. The apparatus of claim 5, wherein the screw drive varies in pitch along at least a portion of a longitudinal length of the screw drive to vary a speed at which the plurality of fiber optic connectors are moved through the system. 7. The system of claim 5, wherein the screw drive includes a flat portion to allow the plurality of fiber optic connectors to be moved independently from the screw drive. 8. The apparatus of claim 1, wherein the second drive mechanism moves a fixture that is coupled to the plurality of fiber optic connectors. 9. The apparatus of claim 1, wherein the first drive mechanism includes a walking beam drive, and the second drive mechanism includes a screw drive. 10. A method for moving a fiber including a plurality of fiber optic connectors through a system for processing the plurality of fiber optic connectors, the method comprising: coupling the plurality of fiber optic connectors to a fixture; and moving the fixture through the system using a screw drive. 11. The method of claim 10, further comprising varying a pitch of the screw drive to vary a speed at which the fixture is moved by the screw drive. 12. The method of claim 10, further comprising providing a flat portion defined by the screw drive to allow the fixture including the plurality of fiber optic connectors to be moved independently from the screw drive. 13. The method of claim 10, further comprising configuring a cycle of the screw drive so that the cycle includes a moving interval, during which the fixture is moved, and a resting interval, during which the fixture is stationary. 14. The method of claim 13, wherein the moving interval of the cycle is approximately 2/3 of the cycle. 15. A method for moving a fiber including a plurality of fiber optic connectors through a system for processing the plurality of fiber optic connectors, the method comprising: loading the fiber onto a cart; loading the plurality of fiber optic connectors into a fixture; moving the cart through the system; and moving the fixture through the system. 16. The method of claim 15, wherein the step of moving the cart further comprises moving the cart through the system using a walking beam drive. 17. The method of claim 15, wherein the step of moving the fixture further comprises moving the fixture through the system using a screw drive. 18. The method of claim 15, wherein the steps of moving further comprise moving the fiber and the plurality of fiber optic connectors in sequence through the system. 19. A method for moving a fiber including a plurality of fiber optic connectors through a system for processing the plurality of fiber optic connectors, the method comprising: loading a spool including the fiber onto a cart; loading a fixture with the plurality of fiber optic connectors; coupling the fixture to the cart; moving the cart to a start position of the system for processing the plurality of fiber optic connectors; detaching the fixture from the cart; using the first drive to move the cart through the system; and using the second drive to move the fixture through the system. | RELATED APPLICATION The present application claims priority to U.S. Patent Provisional Application Ser. No. 60/579,755, Attorney Docket No. 2316.1797USP1, entitled “System and Method for Processing Fiber Optic Connectors” and filed on Jun. 14, 2004, the entirety of which is hereby incorporated by reference. TECHNICAL FIELD The present disclosure relates generally to systems and methods for processing fiber optic connectors. BACKGROUND Fiber optic cables are used in the telecommunication industry to transmit light signals in high-speed data and communication systems. A standard fiber optic cable includes a fiber with an inner light-transmitting optical core. Surrounding the fiber typically is a reinforcing layer and an outer protective casing. A fiber terminates at a fiber optic connector. Connectors are frequently used to non-permanently connect and disconnect optical elements in a fiber optic transmission system. Connectors are typically coupled together through the use of an adaptor. An example adapter is shown in U.S. Pat. No. 5,317,663, the disclosure of which is incorporated by reference. There are many different fiber optic connector types. Some of the more common connectors are FC and SC connectors. Other types of connectors include ST and D4-type connectors. FIG. 1 shows an example SC connector 10 that includes a ferrule 12. The ferrule 12 is a relatively long, thin cylinder preferably made of a material such as ceramic. Other materials such as metal or plastic can also be used to make the ferrule 12. The ferrule 12 defines a central opening 14 sized to receive a fiber of a given cladding diameter. An epoxy is typically placed into the opening 14 prior to inserting the fiber to hold the fiber in place. The ferrule 12 functions to align and center the fiber, as well as to protect it from damage. Referring still to FIG. 1, the ferrule 12 is positioned within a ferrule housing 18 typically made of a material such as metal or plastic. An outer grip 19 is mounted over the ferrule housing 18. The housing 18 is externally keyed to receive the grip 19 at a single rotational orientation. A hub assembly 20 spring biases the ferrule 12 toward the front of the connector 10. A crimp sleeve 37 and boot 28 are located at the rear of the connector 10. As described at U.S. Pat. No. 6,428,215, which is hereby incorporated by reference in its entirety, the connector 10 can be “tuned” by rotating the ferrule 12 relative to the ferrule housing 18 until an optimum rotational position is determined, and then setting the ferrule at the “tuned” or optimum rotational orientation. Connectors are tuned to ensure that when two connectors are coupled together via an adapter, the ends of the fibers being connected are centered (i.e., aligned) relative to one another. Poor alignment between fibers can result in high insertion and return losses. Insertion loss is the measurement of the amount of power that is transferred through a coupling from an input fiber to an output fiber. Return loss is the measurement of the amount of power that is reflected back into the input fiber. FIG. 2 shows an example FC connector 30 having a ferrule 32 mounted within a ferrule housing 34. A key 36 is fitted over the ferrule housing 34. The key 36 is positioned to correspond to a tuned orientation of the ferrule 32. An outer grip or connector 38 mounts over the ferrule housing 34. A hub assembly 40 is fixedly mounted to the ferrule 32. The hub assembly 40 spring biases the ferrule in a forward direction. The connector 30 also includes a dust cap 42 that covers the front of the ferrule 32, and a crimp sleeve 37 and boot 44 mounted at the rear of the connector 30. In addition to tuning, insertion and return loss can be improved by polishing the end faces of the ferrules. During the polishing process, the ferrules are commonly held in a fixture, and the end faces are pressed against a rotating polishing wheel or disk. Frequently, the end faces are polished to form a polished surface oriented along a plane that is perpendicular with respect to the longitudinal axis of the fibers. However, for some applications, the end faces are polished to form a surface aligned at an oblique angle with respect to the longitudinal axis of the fibers. Other process steps are also undertaken to complete the manufacture of fiber optic connectors. For example, after polishing, the end faces of the connector ferrules are often cleaned. Other steps include tuning the connectors, testing the connectors for insertion and return loss, and assembling the various components of the connectors. Historically, the manufacture of fiber optic connectors has been quite labor intensive. Originally, connectors were individually manually polished and individually manually moved through the various processing steps. Manufacturing efficiency improved with the more prevalent use of multi-connector fixtures (e.g., see U.S. Pat. No. 6,396,996), which allowed multiple connectors to be simultaneously processed. While multi-connector fixtures have improved manufacturing efficiencies, further improvements in the area of automation are needed. SUMMARY One aspect of the present disclosure relates to equipment having features adapted to facilitate automating various steps in the process of manufacturing a fiber optic connector. A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate several aspects of the invention and, together with the description, serve to explain the principles of the invention. A brief description of the drawings is as follows: FIG. 1 illustrates a typical prior art SC connector; FIG. 2 illustrates another typical prior art FC connector; FIG. 3 is a schematic diagram of an example embodiment of a connector processing system having features that are examples of inventive aspects in accordance with the principles of the present disclosure; FIG. 4 is a schematic diagram of another example embodiment of a connector processing system having features that are examples of inventive aspects in accordance with the principles of the present disclosure; FIG. 4A is a schematic diagram of an example polishing station of the system of FIG. 4; FIG. 4B is a schematic diagram of an example cleaning station of the system of FIG. 4; FIG. 4C is a schematic diagram of an example tuning station of the system of FIG. 4; FIG. 4D is a schematic diagram of an example testing station of the system of FIG. 4; FIG. 4E is a schematic diagram of an example SC connector adjust station of the system of FIG. 4; FIG. 4F is a schematic diagram of an example FC connector key press station of the system of FIG. 4; FIG. 4G is a schematic diagram of an example dust cap station of the system of FIG. 4; FIG. 5 is a perspective view of an example fixture; FIG. 6 is a top view of the fixture of FIG. 5; FIG. 7 is a side view of the fixture of FIG. 5; FIG. 7A is another side view of the fixture of FIG. 7 with one control knob in a released position; FIG. 8 is an end view of the fixture of FIG. 5; FIG. 9 is an opposite end view of the fixture of FIG. 5; FIG. 10 is a cross-sectional view taken along line 10-10 of the fixture of FIG. 6; FIG. 10A is a cross-sectional view taken along line 10A-10A of the fixture of FIG. 6 with one control knob in the released position; FIG. 10B is an enlarged view of a portion of the fixture of FIG. 10A; FIG. 11 is a perspective view of an example stranded bare fiber support sleeve; FIG. 12 is an exploded perspective view of the support sleeve of FIG. 11; FIG. 13 is a perspective view of an example cart; FIG. 14 is a side view of the cart of FIG. 13; FIG. 15 is a front view of the cart of FIG. 13; FIG. 16 is a top view of the cart of FIG. 13; FIG. 17 is a perspective view of the front panel of the cart of FIG. 13; FIG. 18 is a perspective view of the fixture mount of the cart of FIG. 13; FIG. 19 is a perspective view of an example lead-in conveyor; FIG. 19A is an enlarged view of a portion of the lead-in conveyor of FIG. 19; FIG. 20 is a front view of the lead-in conveyor of FIG. 19; FIG. 21 is a front view of an example lead-out conveyor; FIG. 22 is a cross-sectional view of a portion of a fixture conveyor; FIG. 23 is a perspective view of the fixture conveyor at the polishing station; FIG. 23A is an enlarged view of a portion of the conveyor of FIG. 23; FIG. 23B is an unwrapped view of the portion of the conveyor of FIG. 23A; FIG. 24 is a front view of the conveyor of FIG. 23; FIG. 24A is an enlarged view of a portion of the conveyor of FIG. 24; FIG. 25 is a perspective view of an example cleaning station; FIG. 26 is a perspective view of a portion of the cleaning station of FIG. 25; FIG. 27 is a cross-sectional view of a portion of the cleaning station of FIG. 25; FIG. 28 is another cross-sectional view of a portion of the cleaning station of FIG. 25; FIG. 29 is a side view of an example tuning station; FIG. 30 is a cross-sectional view of the tuning station of FIG. 29; FIG. 30A is an enlarged view of a portion of the tuning station of FIG. 30; FIG. 30B is an enlarged view of a portion of the tuning station of FIG. 30A; FIG. 31 is a perspective view of an example adaptor of the tuning station of FIG. 29; FIG. 32 is an exploded perspective view of portions of the example tuning station of FIG. 29; FIG. 33 is a perspective view of an example testing station; FIG. 34 is a cross-sectional view of the testing station of FIG. 33; FIG. 34A is an enlarged view of a portion of the testing station of FIG. 34; FIG. 35 is a perspective view of an example SC connector adjust station; FIG. 36 is a perspective view of a portion of the SC connector adjust station of FIG. 35; FIG. 37 is a cross-sectional view of the SC connector adjust station of FIG. 35; FIG. 37A is an enlarged view of a portion of the SC connector adjust station of FIG. 33; FIG. 38 is a perspective view of an example FC connector key press station; FIG. 39 is a perspective view of a portion of the FC connector key press station of FIG. 38; FIG. 39A is an enlarged perspective view of a portion of the FC connector key press station of FIG. 39; FIG. 40 is a schematic view of an example dust cap station; FIG. 41 is another schematic view of the dust cap station of FIG. 40 with portions of the station removed; FIG. 41A is an enlarged perspective view of a portion of the dust cap station of FIG. 41; and FIG. 42 is a cross-sectional view of a portion of the dust cap station of FIG. 40. While the invention is amenable to various modifications and alternative forms, the specifics there have been shown by way of example in the drawings and will be described in detail below. It is to be understood, however, that the intention is not to limit the invention to a particular embodiment. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the invention as defined by the appended claims. DETAILED DESCRIPTION In the following detailed description, references are made to the accompanying drawings that depict various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized, and that structural and functional changes may be made without departing from the scope of the present invention. I. First Embodiment of Automated Connectorization System A. System Description FIG. 3 schematically depicts a fiber optic connector processing system 100 having features that are examples of inventive aspects in accordance with the principles of the present disclosure. The system 100 is adapted for use in processing connectorized fiber optic cables 133 (e.g., ribbon or stranded cable). The connectorized cables 133 typically include fiber optic connectors 135 (e.g., SC connectors, FC connectors, ST connectors, or D4) terminated at first ends of the cables 133, and bare fibers 137 (e.g., fibers that have been stripped and cleaved) located at second ends of the cables 133. The bare fibers 137 can be housed within bare fiber support sleeves 139 that protect and prevent bending of the bare fibers, and also facilitate optically coupling the bare fibers 137 to test equipment during processing of the cables 133. After processing of the cables 133, the bare fibers 137 can be used to provide field terminations or to provide splices with other cables. Referring still to FIG. 3, the system 100 includes a plurality of modular processing stations arranged in an assembly line configuration. The processing stations shown include a polishing station 110, a cleaning station 112, a tuning station 114, a test station 116, an SC connector adjust station 118, an FC connector key press station 120, and a dust cap installation station 122. The system 100 also includes a conveying system 124 for conveying the connectorized optical cables 133 through the various processing stations. One or more processing units (e.g., personal computers or other controllers) can be used to control the conveying system 124 and also to control the processes at each of the process stations. The conveying system 124 includes a carrier 126 adapted for carrying any number of optical cables 133 ranging from a single optical cable up to hundreds of optical cables. The carrier 126 is shown carrying fixtures 132 for securing the connectors 135. The fixtures 132 include clamps 141 for holding the connectors 135 as the connectors are processed at the various processing stations. The clamps 141 preferably hold the connectors 135 with ferrules 145 of the connectors exposed so that end faces 147 of the ferrules 145 can be readily accessed for processing. The fixtures 132 also include receiver sockets 143 for receiving the bare fiber support sleeves 139. When mounted within the receiver sockets 143, the ends of the bare fiber support sleeves 139 are exposed to facilitate optically coupling the bare fibers 137 to test equipment during processing. The fixtures of the carrier 126 are preferably adapted to hold a plurality of connectors 135 during processing. In one non-limiting embodiment, the fixtures of the carrier can have a capacity of least 72 connectors 135. The stations are preferably standalone units that are assembled together to form the assembly line. The modularity of the stations allows the stations to be readily removed, added, or rearranged along the assembly line. For example, each station can include wheels to allow for ease in the rearrangement of the different stations. While seven stations have been shown in the embodiment of FIG. 3, it will be appreciated that additional stations can be added, certain stations can be removed, and/or the order of the stations can be changed without departing from the principles of the present disclosure. B. Description of System Operation In use, the carrier 126 initially conveys the connectorized optical cables 135 to the polishing station 110. The polishing station 110 preferably includes a plurality of substations each corresponding to a different polishing function. For example, the polishing substations can be configured with polishing mediums (e.g., films, disks, etc.) of different coarseness, and polishing pads of differing durometers, to achieve different polishing functions. The polishing station 110 can include one or more drive mechanisms for moving the polishing mediums relative to the ferrule end faces 147 of the connectors 135 being processed. For example, the drive mechanisms can spin, oscillate or otherwise move the polishing mediums relative to the ferrule end faces 147. Alternatively, the end faces 147 of the connectors 135 can be moved relative to the polishing mediums. The polishing mediums and/or ferrules 145 of the connectors 135 can be biased to maintain contact between the end faces 147 and the polishing mediums. After the ferrule end faces 147 of the connectors 135 have been polished, the carrier 126 conveys the connectorized cables 133 to the cleaning station 112. At the cleaning station 112, residue or other foreign material deposited on the ferrules 145 of during the polishing stage is preferably removed. In one embodiment, steam and blasts of air (e.g., carbon dioxide) can be used to clean the ferrules 145. After cleaning, the carrier 126 conveys the fixtures 132 to the tuning station 114. At the tuning station 114, the connectors 135 (e.g., SC and FC connectors) are tested for insertion and/or return loss at various incremental rotational positions (e.g., 60 degree increments). The connectors 135 are tuned by inputting light into the connectors 135 at each rotational increment, and comparing the relative amount of light that is output from the bare fiber ends 137 at each increment. The rotational orientation of the tuned position (i.e., “the key location”) is selected to ensure that when two connectors are optically coupled together, the ferrules of the coupled connectors are relatively oriented to provide optimum optical performance. After tuning, FC connectors can be rotated within the fixtures to place the key locations at known rotational positions that are coordinated with subsequent processing steps (e.g., the key press step at the FC connector key press station 120). Alternatively, in the case of SC connectors, the key locations can be stored in memory for use at the SC connector adjust station 118. From the tuning station 114, the carrier 126 moves the connectorized cables 133 to the test station 116. At the test station 116, each of the connectors 135 is tested for insertion loss and return loss to ensure each of the connectors complies with predetermined insertion loss and return loss standards. The connectors 135 are tested by inputting light through the connectors 135 and measuring the quantity of light output through the bare fiber ends 137. Information concerning connector failure is stored in memory for use during subsequent processing operations. If SC connectors are being processed, the carrier 126 moves from the test station 116 to the SC connector adjust station 118. If FC connectors are being processed, the carrier 126 moves from the test station 116, past the SC connector adjust station 118, to the FC connector key press station 120. If ST or D4 connectors are being processed, the carrier moves from the test station 116, past both the SC connector adjust station 118 and the FC connector key press station 120, to the dust cap station 122. At the SC connector adjust station 118, the ferrule of each SC connector (e.g., hub assembly 20 of SC connector 10 shown in FIG. 1) is rotated relative to its corresponding ferrule housing (e.g., housing 18) until the keys of the ferrule housings align with the key locations previously determined at the tuning station 114 and stored in memory. After the SC connector adjustment process has been completed, the carrier 126 carries the SC connectors past the FC connector key press station 120 to the dust cap station 122. At the FC connector key press station 120, keys (e.g., key 36 of FC connector 30 shown in FIG. 2) are pressed on to the bodies of FC connectors at the key mounting locations. The pre-orientation of the rotational positions of the FC connectors at the tuning station 114 ensures that the keys are properly oriented at the optimal tuned or key locations. Thereafter, the carrier 126 moves the FC connectors to the dust cap station 122. At the dust cap station 122, dust caps (e.g., dust cap 42 shown in FIG. 2) are pressed over the ferrules of the connectors. In some embodiments, dust caps are only applied to those connectors that were successfully processed through system 100. For example, dust caps can be placed on only those connectors that receive a passing rating at test station 116. In this manner, during subsequent processing, the presence of a dust cap indicates that the connectors are ready for subsequent processing (e.g., installation of the outer grips). The absence of a dust cap alerts the operator that the connector has failed in some respect, and alerts the operator to remove the connector for re-processing. II. Second Embodiment of Automated Connectorization System A. System Description FIGS. 4 and 4A-4G show an alternative fiber optic connector processing system 200 having features that are examples of inventive aspects in accordance with the principles of the present disclosure. The system 200 includes a plurality of modular processing stations arranged in an assembly line. Similar to the previous embodiment, the processing stations include a polishing station 210, a cleaning station 212, a tuning station 214, a test station 216, an SC connector adjust station 218, an FC connector key press station 220 and a dust cap station 222, all of which are described further below. The system 200 also includes a cart conveying unit 224 for conveying a cart 226 from station to station. See FIGS. 13-18 and accompanying description below. The cart 226 is adapted for carrying one or more connectorized fiber optic cables 133. The system 200 further includes fixture assemblies 300 that can be mounted to and detached from the cart 226. See FIGS. 5-10B and accompanying description below. For clarity, only a few of the fixture assemblies 300 are shown mounted to the cart 226. The fixture assemblies 300 each include a tuning and test fixture 302 for clamping boots 149 of the connectors 135, and a polishing fixture 304 having nests for supporting the ferrules 145 of the connectors 135. The tuning and test fixtures 302 also define receptacles 342 for receiving the bare fiber support sleeves 139 mounted to bare fiber ends 137 of the cables 133. The system 200 further includes a fixture conveyor 240 for conveying the fixture assemblies 300 from station to station along the assembly line. See FIGS. 19-24A and accompanying description below. The fixture conveyor 240 is a separate conveyor from the cart conveyor 224. However, the operation of the fixture conveyor 240 is coordinated with the operation of the cart conveyor 224 such that the fixture assemblies 300 and their corresponding cart 226 move in a side-by-side relationship from station to station. The system 200 includes a main system controller 250 that coordinates the operation of the fixture conveyor 240 with the operation of the cart conveyor 224. The main system controller 250 interfaces with controllers at each of the stations to integrate each station into the overall system. In certain embodiments, the main systems controller 250 can include a personal computer with keyboard access. B. System Operation Overview In general use of the system 200, a spool 260 of fiber optic cable 133 is placed on the cart 226 while the cart is off-line from the cart conveyor 224. Connectors 135 of the fiber optic cables 133 are then clamped within the fixture assemblies 300, and the bare fiber support sleeves 139 are inserted within receptacles 342 defined by the fixture assemblies 300. The fixture assemblies 300 are then secured to the cart 226. After securing the fixture assemblies 300 to the cart 226, the cart 226 is manually wheeled to the cart conveyor 224. The cart 226 then engages the cart conveyor 224 and is conveyed toward the polishing station 210. Prior to reaching the polishing station 210, the fixture assemblies 300 are disconnected from the cart 226 and engaged with the fixture conveyor 240. The fixture conveyor 240 then conveys the fixture assemblies 300 to the polishing station 210 for polishing of the ferrules 145. At the end of the polishing station, the polishing fixtures 304 of fixture assemblies 300 are stripped from the tuning and test fixtures 302 to provide more ready access to the connectors 135 during subsequent processing steps. The tuning and test fixtures 302 are then moved by the fixture conveyor 240 to subsequent processing stations to allow the connectors 135 to be processed (e.g., cleaned, tuned, tested, key adjusted, key pressed, fitted with dust caps or processed by other processing operations). Typically, the tuning and test fixtures 302 are stopped at stations where processing is desired to provide sufficient time for processing. As described with respect to the embodiment of FIG. 3, depending on the type of connector being processed, certain of the stations may be by-passed. The functions performed at each of the stations can be similar to those described with respect to the embodiment of FIG. 3. Movement of the cart 226 is preferably coordinated with the movement of the fixture on the conveyor 240. The conveyor 240 preferably moves the fixtures in a stepwise motion (i.e., the movement is indexed or stepped in fixed increments). The cart conveyor 224 preferably moves the cart 226 in a stepwise motion that corresponds to the stepwise motion generated by the conveyor 240. In this manner, the fixtures 300 (which carry the connectors 135) and the cart 226 (which carries the bulk of the cable 133) remain in a side-by-side relationship throughout the various processing steps. After the dust cap station 222, the fixtures 302 are disengaged from the conveyor 240 and re-connected to the cart 226, and the cart 226 is disengaged from the cart conveyor 224 and manually wheeled to a location for further processing of the connectors 135. For example, at a subsequent location, outer grips can be pressed on the connectors 135. Thereafter, the connectors 135 can be removed from the fixtures 302, and the fixture assemblies 300 can be re-assembled and reloaded with a next batch of connectors 135. The cart 226 can then be wheeled back to the start of the cart conveyor 224 to initiate processing of the next batch of connectors 135. A plurality of carts 226, each including a plurality of connectors 135 mounted in fixture assemblies 300, can be processed by system 200. For example, a plurality of carts 226 can be sequentially loaded into system 200 so that each station of system 200 is eventually occupied at a given point in time. C. System Component Descriptions a. Fixture Assemblies Referring now to FIGS. 5-10B, the fixture assemblies 300 of the system 200 each include the tuning and test fixture 302 as well as the polishing fixture 304. The polishing fixture 304 is detachably mounted to the underside of the tuning and test fixture 302. A latching arrangement, such as a pair of spring latches 306, is used to secure the polishing fixture 304 relative to the tuning and test fixture 302. The polishing fixture 304 also includes alignment pins 308 that fit within openings 309 defined by the tuning and test fixture 302 to maintain alignment between the two fixtures 302, 304. See FIGS. 10 and 10A. Referring to FIGS. 8 and 9, each of the spring latches 306 includes a pair of resilient arms 310 secured to the polishing fixture 304. The resilient arms 310 are biased together and interlocked with a retaining member 312 provided on the tuning and test fixture 302. The polishing fixture 304 can be detached from the tuning and test fixture 302 by pulling downwardly on the polishing fixture 304 with sufficient force to flex the arms 310 of the latches 306 apart such that the arms 310 disengage from the retaining member 312. The polishing fixture 304 of the fixture assembly 300 includes three ferrule nests 314 sized to receive ferrules 145 of the connectors 135. See FIGS. 10, 10A, and 10B. The ferrules 145 protrude downwardly beyond the nests 314 such that the end faces 147 of the ferrules 145 are exposed for polishing. In addition, the ferrule nests 314 form a close tolerance fit as the ends 147 of ferrules 145 extend below the fixture 304. Each ferrule nest 314 also includes a boss 319 with end 317. See FIG. 10B. The boss 319 functions to center the ferrule 145 of each connector 135 and is sized so that the end 147 of the ferrule 145 for both FC connectors and SC connectors extends an equal distance below the fixture 304. Specifically, as shown in FIG. 10B, ends 317 of boss 319 extend into and contact housing 18 of SC connector 135a. In contrast, an end 311 of housing 34 of FC connector 135b contacts the base of the nest 314. In this manner, end faces 147 of both the SC connector 135a and FC connector 135b extend an equal distance below fixture 304. As shown in FIGS. 4, 6, and 10, the polishing fixture 304 also includes an extension 316 that extends beyond the end of the tuning and test fixture 302. The extension 316 provides a location where the polishing fixture 304 can be clamped by a polishing machine at the polishing station 212. Referring to FIG. 8, the tuning and test fixture 302 includes an end opening 315 for receiving retractable retention pins of the cart 226 (see FIG. 18) to mount the fixture assembly to the cart 226. The tuning and test fixture 302 also includes a V-notch 320 (see FIGS. 6 and 7) for interlocking with resilient retention clips provided on the cart 226. The clips interlock with the V-notches 320 to prevent the fixture assemblies 300 from inadvertently rotating on or disengaging from the mounting pins of the cart 226. The tuning and test fixture 302 also include three clamps 230 (best shown in FIGS. 5, 7, 10, 10A, and 10B) adapted for clamping boots 149 of the connectors 135 to hold the connectors 135 during processing. Each of the clamps 330 includes two clamp members 331 between which the boots 149 of the connectors 135 are clamped. Each of the clamp members 331 includes a recessed mid-region 333. The recessed mid-region 330 defines receptacles (e.g., channels or slots) in which the boots 149 of the connectors 135 can be clamped. The recessed mid-regions 333 have generally V-shaped cross-sections with the widths of the recessed mid-regions 333 enlarging as the recessed mid-regions 333 extend in a downward direction. A pair of resilient members 335 (e.g., O-rings) is mounted within each mid-region 333. The resilient members 335 facilitate gripping the boots 149 of the connectors 135. The clamp members 331 are spring biased toward one another (i.e., toward a clamped orientation). The clamp members 331 can pivot slightly to accommodate connectors with boots of differing dimensions and tapers. See, for example, FIG. 10B, which illustrates clamp members 331 clamped to boot 28 of SC connector 135a and boot 44 of FC connector 135b. In addition, when the clamp members 331 are moved from the closed to the open position, the clamp members 331 move slightly in an upward direction during the beginning of movement to the open position so that tension on the connector 135 is released prior to release of the boot of the connector. The tuning and test fixture 302 further includes clamp control knobs 355 for manually opening and closing the clamps 230. In manual operation, as illustrated in FIGS. 7A and 10A, control knob 355a is pulled away from fixture 302 to open the clamp 230a to allow a connector 135 to be inserted into or removed from clamp 230a. Knob 355a can be rotated a quarter turn to temporarily lock clamp 230a in the open position. In an automatic operation, internal components of fixture 302 can be actuated to open clamps 230a, 230b, and 230c without requiring control knobs 355a, 355b, and 355c to be manually pulled upward. The tuning and test fixture 302 further includes a receiver 340 defining the receptacle 342 for receiving one of the bare fiber support sleeves 139, which is illustrated in FIGS. 11 and 12 and described further below. The receiver 340 extends through the main body of the tuning and test fixture 302 and includes a lower portion that is accessible from the underside of the main body 302. See FIG. 10A. When the bare fiber support sleeve 139 is mounted within the receiver 340, the ends of the bare fibers are accessible from the underside of the tuning and test fixture 302 for allowing the fibers to be optically connected to a test structure such as a remote test head for use in insertion loss and return loss testing. The tuning and test fixture 302 further includes upper and lower pins 344 and 346. See FIGS. 7 and 10. The upper pin 344 projects upwardly from the main body of the fixture 302, and the lower pin 346 projects downwardly from the main body of the fixture 302. The pins 344, 346 are adapted to engage the fixture conveyor 240. See FIG. 22. As shown in FIGS. 11 and 12, the bare fiber support sleeves 139 include a top portion 151 that is pivotally mounted to a base portion 152. A fiber holder 156 including ferrules 153 is configured to receive and hold stranded bare fiber. In use, bare stranded fiber is extended through channel 154 formed in base portion 152 and into fiber holder 156. Previously stripped ends of the stranded fiber are positioned to extend through ferrules 153. Then, the top portion 151 is pivoted toward the base portion 152 until in the position illustrated in FIG. 11. Next, the stripped ends of the fibers that extend from ferrules 153 are cleaved. In one embodiment, a cleaver having product no. CT-107, manufactured by Fujikura Ltd. of Tokyo, Japan, is used to cleave the striped fiber. Once the fibers are cleaved, the bare fiber support sleeve 139 is positioned in the tuning and test fixture 302, as shown in FIGS. 5, 7, and 10A. In this position, the ferrules 153 of support sleeve 139 are accessible below the fixture 302. If, instead of stranded fiber, ribbon fiber is being processed, a similar support sleeve can be used. However, for ribbon fiber, no ferrules are required because the ribbon structure provides adequate support for the fibers. In addition, for ribbon fiber, the fiber can be both stripped and cleaved once the fiber has been placed in the support sleeve. b. Cart Assembly FIGS. 13-18 show various views of the cart 226. The cart 226 includes a base 400. A rear portion of the base 400 defines a platform 402 for supporting a spool of fiber optic cable. Rollers 403 are provided on the platform 402 for facilitating loading and unloading spools of fiber optic cable to or from the platform 402. The sides of the platform 402 are enclosed by side walls 404 and the front of the platform 402 is enclosed by a front wall 406. The back of the platform 402 is open to facilitate loading fiber optic spools onto the platform. Handles 408 are provided at the top sides of the side walls 404 for facilitating maneuvering of the cart 226. With respect to the spools carried by the cart 226, the spools typically range in diameter from 12 inches 36 inches. The spools can carry anywhere from one fiber optic cable to hundreds of fiber optic cables. In the case where a large number of fiber optic cables are wrapped about the spool, the fibers are typically bundled within one or more bundling sheathes. Sub-bundles can be provided within the main sheathed bundles. The fiber optic cables can range in length from a few feet to hundreds of feet. While the cables will typically be provided on spools, it will be appreciated that for short length cables, spools may not be needed. Referring to FIGS. 13-16, casters 410 are mounted to the underside of the base 400. The casters 410 include pivoting caster wheels 412. The caster wheels 412 include central grooves 414. See FIG. 14. A pair of racks or ladders 416 is also mounted to the underside of the base 400. The ladders 416 provide structure for allowing the cart conveyor 224 to engage the cart 226. The cart 226 further includes a front cable management structure 420 that projects forwardly from the front wall 406. The cable management structure 420 includes an upright front panel 422. See FIGS. 13, 15, and 17. Cable management structures such as spools 424 for managing excess cable and clamps 426 for clamping cables are mounted to the front panel 422. Two cable clamps 428 are mounted to the top of the upright panel 422. The clamps 428 are adapted for clamping a sheathed portion of a bundle of fiber optic cables. The sheathed portion of the bundles is preferably clamped at the clamps 428, and extensions of the fiber optic cables bundled within the sheath are typically fanned downwardly from the clamps 428 with connectorized ends 135 of the fiber optic cables being clamped within the fixture assemblies 300. Excess length of cable corresponding to the connectors being processed, as well as extra cables having connectors that have already been processed or are soon to be processed, can be managed by wrapping such cables around the spools 424. The cart 226 further includes a fixture mount 450. See FIGS. 14 and 18. The fixture mount 450 includes a plurality of mounting pins 452 adapted to be received within the rear openings 315 of the tuning and testing fixtures 302. The depicted mount 450 is adapted for mounting 24 fixture assemblies 300. However, it will be appreciated that the capacity of the mount 450 can be varied without departing from the principles of the disclosure. The fixture mount 450 also includes resilient retention clips 454 that engage the notches 320 in the tuning and test fixtures 302 to prevent the fixtures 302 from inadvertently disengaging from the pins 452. The fixture mount 450 further includes a handle 456 for retracting the fixture mount 450 to disengage the fixture assemblies 300 from the cart 226 after the fixture assemblies 300 have been engaged by the fixture conveyor 240. By pivoting the handle 456, the pins 452 are withdrawn from the rear openings 315 of the tuning and test fixtures 302 to disengage the fixture assemblies 300 from the cart 226. As the fixture mount 450 is retracted, the retaining clips 454 flex upwardly to allow the fixture assemblies 300 to be disengaged from the cart 326. The cart 226 further includes a bin 460 for receiving and storing the polishing fixtures 304. See FIG. 14. As will be described below, after the polishing processes have been completed at the polishing station 212, the polishing fixtures 304 are stripped from the tuning and test fixtures 302. After the polishing fixtures 304 have been stripped, the polishing fixtures 304 slide by gravity down a ramp and into the bin 460 for storage. Subsequently, the polishing fixtures 304 are removed from the bin 460 and recoupled to fixtures 302 for processing the next batch of connectors. c. Cart Conveyor The cart conveyor 224 is depicted in FIG. 4 as including a pair of parallel tracks 600 for receiving the caster wheels 412 of the cart 226. Center guides 602 are located within each of the tracks 600. When the cart 226 is conveyed along the tracks 600, the grooves 414 of the wheels 412 ride along the center guides 602. The cart conveyor 224 also includes a drive mechanism for moving the cart 226 along the tracks 600. It will be appreciated that the drive mechanism can have any number of different configurations. In the depicted embodiment, the drive mechanism includes a pneumatically powered walking beam drive 661. In other embodiments, the drive mechanism can include a chain drive, a stepper motor drive, a rack and pinion drive, or any other drive suitable for conveying the cart in a controller manner. The walking beam drive 661 includes a pair of parallel beams 662a, 662b having lugs 663 for engaging the ladders 416 on the underside of the cart 226. Vertical pneumatic cylinders 665 raise and lower the beams 662a, 662b and horizontal pneumatic cylinders 667 move the rails horizontally. The left beam 662a is preferably moved in a square pattern. For example, beam 662a is raised (e.g., by cylinders 665) such that the lugs 663 engage the left ladder 416 of the cart 226, is moved horizontally forward (e.g., by cylinder 667) to move the cart 226 forward one increment, is lowered (e.g., by cylinders 665) to disengage the lugs 663 from the cart 336, and is then horizontally returned to its initial position (e.g., by cylinder 667) where it is ready to repeat the cycle. The right beam 662b can be moved in a similar pattern. Alternatively, the beam 662b can simply be raised and lowered to selectively engage right ladder 416 the cart 226. For example, the right beam 662b can be raised when the left beam 662a is lowered to prevent unintentional movement of the cart 226, and then lowered when the lugs 663 of the left beam 662a are in engagement with the cart 226. d. Fixture Conveyor Referring now to FIGS. 4 and 19-24A, the fixture conveyor 240 is shown including two generally parallel guide rails 700 and two generally parallel screw drives 702. The screw drives 702 can be powered by a drive mechanism 707 (see FIG. 21) such as a pneumatic drive, a servo-motor drive, or any other drive suitable for rotating the screw drives 702. The screw drives 702 are vertically offset from one another (i.e., set at different elevations) such that one of the screw drives 702 is adapted to engage the upper guide pins 344 of the fixtures 302, and the other of the screw drives 702 is adapted to engage the lower pins 346 of the fixtures 302. See FIGS. 20, 21, and 22. As shown in FIG. 22, the pins 344, 346 ride within slots 703 defined within the screw drives 702. By rotating the screw drives 702, the fixture 300, including the tuning and test fixture 302 and polishing fixture 304, is conveyed along the screw drives 702. The slots 703 of the screw drives 702 are generally arranged at an angled pitch configuration 709 for ⅔ of a turn and then a non-angled configuration 701 for the remaining ⅓ of the turn. See FIGS. 23A and 23B. This configuration results in the fixture assemblies 300 being conveyed along the screw drives 702 for ⅔ of the turn (i.e., in angled pitch 709) and then dwelling at one spot for ⅓ of the turn (i.e., in non-angled configuration 701) for each revolution of the screw drives 702. The dwell times provided by the non-angled portions 701 of the slots 703 assist in preventing inertial bumping of the fixtures during conveying, as well as allow the screw drives 702 to reengage the fixture 300 after each polishing cycle, as described further below. In one embodiment, the fixtures 300 are moved about 1 inch per revolution of the screw drives 702 and are typically moved in 2 inch increments between processing steps. To correspond with the fixture conveyor 240, the cart conveyor 224 preferably moves the cart 226 in the same 2 inch increments. While 2 inch increments are preferred, it will be appreciated that the size of the increments can be varied without departing from the principles of the disclosure. As shown at FIGS. 23, 24, and 24A, the screw drives 702 also preferably include flat regions 348 located at the polishing station 210. The flat regions 348 are positioned to correspond with the non-angled portions 701 of the slots 703. The flat regions 348 allow the pins 344, 346 of the fixtures 302 to be disengaged from the screw drives 702 during polishing operations, as described further below. After polishing, the non-angled portions 701 of the slots 703 allow the pins 344, 346 to be reengaged with the screw drives 702 upon revolution of the screw drives. The screw drives 702 also include regions of increased slot pitch 705 before and after entering the flat regions 348 of the polishing station 210. See FIG. 24A. The increased pitch regions 705 provide an increased spacing between the group of fixtures 300 being polished at the polishing station 210, and fixtures 300 located before and after the polishing station 210. This spacing allows the group of fixtures 300 at the polishing station 210 to be moved longitudinally during polishing without contacting adjacent fixtures. While a screw drive arrangement is preferred for conveying the fixtures, it will be appreciated that other types of drive mechanisms such as rack and pinion drives, chain drives, belt drives or other drives could also be used. The screw drives 702 can be powered by a drive mechanism 707 such as one or more servo-motors. If a single servo-motor is used, belts or other torque transfer arrangements can be used to transfer torque from the servo to the screw drives 702 for turning the screw drives 702. The fixture conveyor 240 can also include a lead-in section 708 and a lead-out section 709. See FIGS. 19-21. The lead-in and lead-out sections 708, 709 preferably have a length generally equal to at least one cart length. At the lead-in and lead-out sections 708, 709, straight longitudinal slots 349 can be formed in screw drives 702 to allow pins 344, 346 of fixtures 300 to slide therein, thereby facilitating engaging the fixture pins 344, 346 with the screw drives 702 as the cart 226 is lead into the assembly line, and to facilitate disengaging the fixture pins 344, 346 from the screw drives 702 as the cart 226 is lead out of the assembly line. See FIG. 19A. e. Polishing Station Referring to FIGS. 4 and 4A, the depicted polishing station 210 includes a plurality of polishing substations 210a-210g. Each substation includes three polishing pads 750 that can be individually raised and lowered by separate lift mechanisms (e.g., pneumatic cylinders). Polishing films are positioned between the pads 750 and the ferrule end faces 147 of the ferrules 145 nested within the polishing fixtures 304 of the fixture assemblies 300. By lifting the polishing pads 750, the polishing films are pressed into contact with the ferrule end faces 147. The various polishing substations 210a-210g can provide various polishing functions. For example, the substation 210a can provide an epoxy and hackle removal function. Later substations can provide radius and apex shaping functions. The substations can utilize polishing films having increasingly fine grit sizes to provide the final polished end faces. The substations can provide a chemical mechanical polishing effect by using polishing films having reactive components. An example film material includes cerium oxide. Example polishing steps are disclosed in U.S. Pat. No. 6,599,030 to Millmann, which is hereby incorporated by reference. The polishing station 210 can include a fluid injection system for cleaning the polishing films between polishing cycles. For example, the fluid injection system can include one or more jets that sprays de-ionized water interspersed in a stream of high-pressure air to remove debris and other unwanted particles from the polishing films. The polishing station 210 also includes a drive mechanism 755 for moving the fixture assemblies 226 along a horizontal plane relative to the polishing films. The drive mechanism 755 can include an X-Y table. A controller 756 can be used to program the polishing mechanism 755 to move or oscillate the fixture assemblies 300 along predetermined polishing patterns. The drive mechanism 755 includes clamps 757 adapted to clamp on the extensions 316 of the polishing fixtures 304 to secure the fixture assemblies 300 to the drive mechanism 755. The drive mechanism 755 preferably simultaneously moves all of the fixture assemblies 300 at the polishing station 210 along the preprogrammed polishing pattern. Further details regarding aspects of the polishing system can be found in U.S. patent application Ser. No. 10/356,358 to Bianchi, filed on Jan. 31, 2003 and entitled “Apparatus and Method for Polishing a Fiber Optic Connector,” which is hereby incorporated by reference. In operation of the polishing station 210, the fixture assemblies 300 are moved from substation to substation by the screw drives 702. When the fixture assemblies 300 reach each substation, the clamp 757 corresponding to the given substation clamps down on the extension 316 of the polishing fixture 304. When the fixture assemblies 300 are aligned with the substations, the screw drives 702 are positioned with the flats 348 oriented to not interfere with the fixture pins 344, 346. See FIGS. 24 and 24A. Therefore, the drive mechanism 755 can readily move the fixture assemblies 300 without interference from the screw drives 702. After a polishing sequence has been completed, the clamps 757 are released, the screw drives 702 are rotated, causing the pins 344, 346 to re-engage the slots 703, and the fixture assemblies 300 are moved to the subsequent polishing substation. Thereafter, the process is repeated until the polishing process is complete. When the fixtures are moved along the fixture conveyor 240, the fixtures 300 ride along guide rails 700. As shown, for example, at FIGS. 7, 10, and 22, the guide rails 700 are adapted to ride against shoulder portions 321 of the tuning and test fixture 302 such that a mid-portion of the test and tuning fixture 302 is captured between the rails 700. The rails 700 include portions that pivot about points 710 located at the polishing station 210 (see FIGS. 24 and 24A). During polishing, the portions of rails 700 pivot about points 710 outwardly toward the corresponding screw drives 702 to provide clearance for allowing the fixtures 300 to be moved laterally by the drive mechanisms of 755 along the desired polishing pattern. A stripping substation 760 is located at the end of the polishing station 210. At the stripping station 760, the polishing fixtures 304 are pulled downwardly from the tuning and test fixtures 302 to disengage the polishing fixtures 304 from the tuning and test fixtures 302 (e.g., by pulling downwardly on the polishing fixture 304 with sufficient force to flex the arms 310 of the latches 306 apart such that the arms 310 disengage from the retaining member 312, as shown in FIGS. 8 and 9). Once disengaged, the polishing fixtures 304 slide via gravity down a ramp into the storage bin for 460 of the cart 226. See FIG. 14. By removing the polishing fixture 304, improved access is provided to the connectors 135 for subsequent processing. Since the connectors are clamped at the boot 149, the lower ends of the connectors 135 are fully exposed and readily accessible from under the tuning and test fixtures 302. f. Cleaning Station Referring to FIGS. 4, 4B, and 25-28, the cleaning station 212 includes substations 212a, 212b for cleaning the ferrule end faces 147 of the connectors 135. The substation 212a includes steam recesses 790 into which the lower ends of the connectors 135 are inserted to expose the ferrules 145 to cleansing steam. Steam is provided to the steam recesses 790 by nozzles 791 that are connected to a steam source, and dry air is provided by nozzles 797. The substation 212b includes air stream recesses 795 into which the lower ends of the connectors 135 are inserted. The air stream recesses 795 are pneumatically coupled to a source of compressed gas. The source of compressed gas provides a pressurized gas stream to the recesses for cleaning the ferrules 145. In one embodiment, the pressurized gas includes carbon dioxide. Operation of the cleaning module 212 can be controlled by a controller 799 that interfaces with the main system controller 250. In use, the fixture conveyor 240 advances a fixture 302 to substation 212a and the fixture stops at a position where the connectors 135 align with the steam recesses 790. The substation 212a is then actuated towards the fixture 302 until end faces 147 of the connectors 135 are positioned to extend into the recesses 790. See FIG. 27. Steam (see arrows S) is applied to the ferrules 145 of the connectors 135 by nozzles 791, and dry air is applied by nozzles 797 (see arrows A). Once the steam cleaning process is complete, fixture 302 is indexed to the substation 212b, where the connectors 135 are cleaned with air in a similar manner. Referring to FIG. 28, in one embodiment, an air seal is used to seal the substations 212a, 212b when cleaning the connectors 135. When steam, illustrated by arrows S, is applied to the end faces 147 of connector 135 during cleaning at substation 212a, air is forced through passage 792 and out recess 790 surrounding the connector 135 (see arrows B). The air that is forced through passage 792 and out of recess 790 acts as a barrier to the steam and other debris removed from end faces 147 from exiting the substation 212a. In this manner, the portions of connector 135 located outside of the substation 212a are maintained in a clean condition. After the air cleaning, the fixture 302 is moved to the tuning station 214. g. Tuning Station Referring to FIGS. 4, 4C, and 29-32, the tuning station 214 includes three master tuning connectors 800 and a remote test head 806 for use in inputting light into the connectors 135, and monitoring the light output through the bare fiber ends 137 held within the support sleeves 139. The tuning connectors 800 can be raised and lowered by a lift mechanism 802, and individually rotated by rotational drives 803. A conventional optical testing apparatus 808 is optically connected to the master tuning connectors 800 and the remote head 806. In one embodiment, the testing apparatus 808 includes a light member frame having product no. 8163A, a laser light source having product no. HP 81654A, a light meter having product no. 81618A, and a remote head having product no. 91623A, all being manufactured by Agilent Technologies of Palo Alto, Calif. In addition, a fiber optic switch (not shown) is used to switch the light signals entering the testing apparatus 808 so that the testing apparatus 808 can be used for all three master tuning connectors 800. Intermediate adapters 860 are positioned between the tuning connectors 800 and the connectors 135 being processed. See FIGS. 30B and 31. The adapters 860 include a boss 813 that surrounds a split sleeve 861 sized to receive the ferrules of the tuning connector 800 and connector 135. A clamp 862 provides a compression force on the lower portion of the split sleeve 861 to retain the ferrule of the tuning connector 800 in the split sleeve 861 of the adapter 860. A module controller 810 interfaces with the testing apparatus 808 and various other components to control operation of the station 214. The module controller 810 also interfaces with the with the main system controller 250. In addition, a machine controller 811 interfaces with the structural components of the station 214 to control movement of the various components of the station 214, such as lift mechanism 802 and rotational drives 803. In use of the tuning station 214, the screw drive 702 conveys a fixture 302 to a position where the connectors 135 held by the fixture 302 are positioned directly above corresponding master tuning connectors 800. An alignment mechanism 814 is used to align the fixture 302 with respect to the station 214, and an alignment mechanism 809 is provided for retaining the ferrules of the connectors in direct alignment with the master tuning connectors 800. See FIG. 32. For SC connectors, fingers 819 are included on alignment mechanism 809 to prevent rotation of the connectors 135 during tuning. Once the ferrules of the connectors 135 are aligned over the tuning connectors 800, the tuning connectors 800 are raised to provide optical connections with the connectors being processed. Adapters 860 provide the connection between the tuning connectors 800 and the connectors 135 being processed. The bare fiber ends held within the support sleeve 139 mounted within the receiver 342 of the fixture 302 are also optically coupled to the remote head 806. Once the connectors 135 and the bare fiber ends 137 have been coupled to the test apparatus 808 respectively by the tuning connectors 800 and the remote head 806, the test apparatus 808 injects light through the tuning connectors 800 and into the connectors 135 being processed. From the connectors 135, the light travels through the optical fibers to which the connectors 135 are terminated and exits the fibers through the bare fiber ends 137 into the remote head 806. In this manner, by detecting the amount of light that is transferred from the connectors 135 to the bear ends 137 of the fibers, the testing unit 808 can determine the insertion loss or return loss rating for the connectors 135. After testing the connectors 135 at a first rotational orientation, the master tuning connectors 800 are lowered by the lift mechanism 802, rotated an increment (e.g., 60 degrees) by the rotational drives 803, and then raised back up by the lift mechanism 802 to reconnect the tuning connectors 800 with the connectors 135. The testing device 808 is then used to test the connectors at the second rotational position. This process is repeated a plurality of times until each of the rotational positions of the connectors 135 have been tested for tuning purposes. After this process has been completed, the various readings are compared to determine the appropriate key location. For SC connectors, the key locations of each of the connectors are stored in memory. For FC connectors, the boots 149 of the connectors 135 are released from the fixture clamps 330 while the connectors 135 remain in sleeves 861 of adapters 860. The rotational drives 808 are then used to turn the master cables 800 and associated adapters 860, which in turn causes the connectors 135 to individually rotate. Each connector 135 is rotated until the connector 135 is located at the tuned orientation, which is coordinated with subsequent processing at the FC connector key press station 270. The fixture clamps 330 are then reengaged on boots 149 of the connectors 135 to maintain the connectors 135 in the desired rotational orientation. h. Test Station Referring now to FIGS. 4, 4D, and 33-34A, the test station 216 includes a master test connector 850 that is moved up and down by a lift mechanism 851 and moved laterally by a lateral drive mechanism 853. The test station 216 also includes a test unit including a remote test head 855 that optically couples to the bare fiber ends of the connectors 135 held by the fixture 302. In one embodiment, the test unit 859 is an IQS-510P Industrial PC including an IQS-1700 laser, an IQS-3250 light meter, and an OHS-1700 remote head, all manufactured by EXFO of Quebec, Canada. The test station 216 further includes a fiber optic testing device 859 optically coupled to the master test connector 850 and the remote test head 855. A controller 891 interfaces with the various components and also with the main controller 250. In use, the fixture conveyor 240 advances a fixture 302 to the test station 216. The master connector 850 is then moved from connector 135 to connector 135 by the lift and lateral drive mechanisms 851, 853. At each connector 135, the test unit is used to take return loss and insertion loss reading. The test results are stored in memory for use in identifying which connectors complied with acceptable return loss and insertion loss parameters. i. SC Connector Adjust Station As shown at FIGS. 4, 4E, and 35-37A, the SC connector adjust station 218 includes an adjust arrangement 900 having a clamp 902 and a connector body receiver 904. The SC connector adjust station 218 also includes a lateral drive 911 for moving the adjust arrangement 900 from connector to connector on a fixture 302, and a lift mechanism 912 for raising and lowering the adjust arrangement 900. See FIG. 36. The SC connector adjust station 218 further includes a rotational drive 910 for turning the clamp 902 relative to the connector body receiver 904, and a clamp actuator 906 for opening and closing the clamp 902. A controller 913 interfaces with the various components of the station and also interfaces with the main controller 250. In use, the fixture conveyor 240 advances a loaded fixture 302 to the SC connector adjust station 218. Once the fixture is positioned at the station 218, the lateral drive 911 moves the adjust arrangement 900 laterally to a position beneath a first connector 135 held by the fixture 302. The lift mechanism 912 then lifts the adjust arrangement 900 to a position where a lower end of the connector 135 (e.g., housing 18 shown in FIG. 1) is nested within the connector body receiver 904 to prevent the housing from rotating, and the clamp 902 is aligned with a ferrule hub (e.g., hub assembly 20) of the connector 135. The clamp 902 then clamps on the ferrule hub of the connector 135. See FIGS. 37 and 37A. Thereafter, the rotational drive 910 rotates the claim 902 and associated clamped ferrule relative to the housing of the connector 135 to adjust the ferrule relative to the key position of the housing. Preferably, the ferrule of the connector is rotated to a position where the key aligns with the tuned key position determined at the tuning station 214. Finally, once the ferrule of the connector 135 is in the desired rotational position, the clamp 902 releases the ferrule of the connector 135, and the lift mechanism 912 lowers the adjust arrangement 900. The adjust arrangement 900 is then moved by the lateral drive 911 from one to the other of the remaining two connectors 135 in fixture 302 and the same tuning process is repeated. In the illustrated embodiment, a laser sensor 915 emits a laser that is trained on external features of the connector 135 such as the hub assembly 20. See FIG. 1. For example, the laser sensor 915 can be used to verify that the hub assembly 20 of the connector 135 has been rotated by the adjust arrangement 900. j. FC Connector Key Press Station Referring to FIGS. 4, 4F, and 38-39A, the FC connector key press station 220 includes a key holder 920 including clamps 932 for clamping each connector 135 prior to application of a key element (e.g., key 36 of FIG. 2, and a pin 933 for holding each key element prior to application. The key holder 920 is moved laterally by a lateral drive 922 and is raised up and down by a lift 923. The FC connector key press station 220 also includes a product handler 926 for feeding key elements to the key holder 920. The product handler 926 includes a bin 928 for holding the key elements and a feed mechanism 930 for feeding the key elements to the key holder 920. A controller 925 controls operation of the various components of the station and also interfaces with the main controller 250. In use, the fixture conveyor 240 advances a loaded fixture 302 to the station 220. Prior to the fixture 302 reaching the station 220, the key holder 920 is moved so that pin 933 can accept a key from the product handler 926. When the fixture is positioned at the station 220, clamps 932 are closed to capture a portion of the housing of each connector 135. Lateral drive 922 moves the pin 933 of the key holder 920 to a position beneath a first FC connector 135 held by the fixture 302. The lift 923 then lifts the pin 933 of the key holder 920 to press the key onto the connector 135. Thereafter, the pin 933 of the key holder 920 returns to the product handler 926 to receive another key, and the process is repeated until all three connectors 135 held by the fixture 302 have been fitted with a key. k. Dust Cap Installation Station Referring to FIGS. 4, 4G, and 40-42, the dust cap station 222 includes a cap holder 950 that is laterally moved by a lateral drive 951 and is raised and lowered by a lift 953. The dust cap station 222 also includes a product handler 955 for conveying dust caps 970 (e.g., dust cap 42 of FIG. 2) to the dust cap holder 950. The product handler 955 includes a bin 957 for storing the dust caps 970 and a conveyor 959 for moving the dust caps from the bin 957 to a location where the dust caps can be picked up by the dust cap holder 950. A controller 973 controls operation of the components of the station and also interfaces with the main controller 250. In use, the fixture conveyor 240 advances a loaded fixture 302 to the station 222. Prior to the fixture 302 reaching the station 222, the dust cap holder 950 is moved to accept a dust cap 970 from the product handler 955. When the fixture 302 is positioned at the station 222, alignment fingers 972 close to align the connector 135 relative to the dust cap holder 950 (see FIG. 41A), and the lateral drive 951 moves the dust cap holder 950 to a position beneath a first connector 135 held by the fixture 302. The lift 953 then raises the dust cap holder 950 to press the dust cap 970 onto the connector 135. Thereafter, the dust cap holder 950 returns to the product handler 955 to receive another dust cap 970, and the process is repeated until all three connectors 135 held by the fixture 302 have been fitted with a cap 970. In one embodiment, connectors 135 that fail at any station of system 200 (e.g., receive a failing rating at the test station 216) are not fitted with a dust cap 970. In this manner, the absence of a dust cap 970 functions as an indicator for allowing an operator to know which connectors 135 failed and which are in need of reprocessing. | <SOH> BACKGROUND <EOH>Fiber optic cables are used in the telecommunication industry to transmit light signals in high-speed data and communication systems. A standard fiber optic cable includes a fiber with an inner light-transmitting optical core. Surrounding the fiber typically is a reinforcing layer and an outer protective casing. A fiber terminates at a fiber optic connector. Connectors are frequently used to non-permanently connect and disconnect optical elements in a fiber optic transmission system. Connectors are typically coupled together through the use of an adaptor. An example adapter is shown in U.S. Pat. No. 5,317,663, the disclosure of which is incorporated by reference. There are many different fiber optic connector types. Some of the more common connectors are FC and SC connectors. Other types of connectors include ST and D4-type connectors. FIG. 1 shows an example SC connector 10 that includes a ferrule 12 . The ferrule 12 is a relatively long, thin cylinder preferably made of a material such as ceramic. Other materials such as metal or plastic can also be used to make the ferrule 12 . The ferrule 12 defines a central opening 14 sized to receive a fiber of a given cladding diameter. An epoxy is typically placed into the opening 14 prior to inserting the fiber to hold the fiber in place. The ferrule 12 functions to align and center the fiber, as well as to protect it from damage. Referring still to FIG. 1 , the ferrule 12 is positioned within a ferrule housing 18 typically made of a material such as metal or plastic. An outer grip 19 is mounted over the ferrule housing 18 . The housing 18 is externally keyed to receive the grip 19 at a single rotational orientation. A hub assembly 20 spring biases the ferrule 12 toward the front of the connector 10 . A crimp sleeve 37 and boot 28 are located at the rear of the connector 10 . As described at U.S. Pat. No. 6,428,215, which is hereby incorporated by reference in its entirety, the connector 10 can be “tuned” by rotating the ferrule 12 relative to the ferrule housing 18 until an optimum rotational position is determined, and then setting the ferrule at the “tuned” or optimum rotational orientation. Connectors are tuned to ensure that when two connectors are coupled together via an adapter, the ends of the fibers being connected are centered (i.e., aligned) relative to one another. Poor alignment between fibers can result in high insertion and return losses. Insertion loss is the measurement of the amount of power that is transferred through a coupling from an input fiber to an output fiber. Return loss is the measurement of the amount of power that is reflected back into the input fiber. FIG. 2 shows an example FC connector 30 having a ferrule 32 mounted within a ferrule housing 34 . A key 36 is fitted over the ferrule housing 34 . The key 36 is positioned to correspond to a tuned orientation of the ferrule 32 . An outer grip or connector 38 mounts over the ferrule housing 34 . A hub assembly 40 is fixedly mounted to the ferrule 32 . The hub assembly 40 spring biases the ferrule in a forward direction. The connector 30 also includes a dust cap 42 that covers the front of the ferrule 32 , and a crimp sleeve 37 and boot 44 mounted at the rear of the connector 30 . In addition to tuning, insertion and return loss can be improved by polishing the end faces of the ferrules. During the polishing process, the ferrules are commonly held in a fixture, and the end faces are pressed against a rotating polishing wheel or disk. Frequently, the end faces are polished to form a polished surface oriented along a plane that is perpendicular with respect to the longitudinal axis of the fibers. However, for some applications, the end faces are polished to form a surface aligned at an oblique angle with respect to the longitudinal axis of the fibers. Other process steps are also undertaken to complete the manufacture of fiber optic connectors. For example, after polishing, the end faces of the connector ferrules are often cleaned. Other steps include tuning the connectors, testing the connectors for insertion and return loss, and assembling the various components of the connectors. Historically, the manufacture of fiber optic connectors has been quite labor intensive. Originally, connectors were individually manually polished and individually manually moved through the various processing steps. Manufacturing efficiency improved with the more prevalent use of multi-connector fixtures (e.g., see U.S. Pat. No. 6,396,996), which allowed multiple connectors to be simultaneously processed. While multi-connector fixtures have improved manufacturing efficiencies, further improvements in the area of automation are needed. | <SOH> SUMMARY <EOH>One aspect of the present disclosure relates to equipment having features adapted to facilitate automating various steps in the process of manufacturing a fiber optic connector. A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. | 20040712 | 20080401 | 20051215 | 71692.0 | 0 | EL SHAMMAA, MARY A | DRIVE FOR SYSTEM FOR PROCESSING FIBER OPTIC CONNECTORS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,758 | ACCEPTED | Intra-and/or inter-system interference reducing systems and methods for satellite communications systems | A first radio signal is received via a first satellite reception path, for example, an antenna or spot beam, which serves a satellite cell. The received first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the satellite cell. A second radio signal is received via a second satellite reception path, for example, via another antenna or spot beam of the system and/or via a satellite antenna beam of another system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed to recover the desired satellite uplink signal. | 1. A method of operating a satellite radiotelephone communications system, the method comprising: receiving a first radio signal via a first satellite reception path that serves a satellite cell, the received first radio signal including a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the satellite cell; receiving a second radio signal via a second satellite reception path, the second radio signal including a measure of the interfering signal and/or a measure of the desired satellite uplink signal; and processing the first and second radio signals to recover the desired satellite uplink signal. 2. A method according to claim 1, wherein the second satellite reception path is configured to preferentially receive radio transmissions from an area outside of the satellite cell. 3. A method according to claim 2, wherein the area outside of the satellite cell comprises another satellite cell that uses the same frequency and/or a coverage area of another satellite communications system that uses the same frequency. 4. A method according to claim 2, wherein the first and second satellite reception paths comprise respective first and second spot beams that serve respective first and second satellite cells of the satellite radiotelephone communications system. 5. A method according to claim 4, wherein at least one radiating source in a region of the second satellite cell uses a frequency assigned to the first satellite cell for satellite and/or terrestrial communications. 6. A method according to claim 4, wherein the second satellite cell is adjacent a third satellite cell that uses a frequency assigned to the first satellite cell. 7. A method according to claim 4, wherein the second satellite cell overlaps or is adjacent a terrestrial cell that uses a frequency assigned to the first satellite cell. 8. A method according to claim 4, wherein the satellite radiotelephone communications system comprises a first satellite radiotelephone communications system, and wherein the second satellite cell overlaps or is adjacent a coverage area of a second satellite radiotelephone communications system. 9. A method according to claim 2, wherein the first satellite reception path comprises a first satellite antenna positioned at a first satellite of the satellite radiotelephone communications system, and wherein the second satellite reception path comprises a second satellite antenna positioned at a second satellite of the satellite radiotelephone communications system. 10. A method according to claim 2, wherein the first satellite reception path comprises a first satellite antenna positioned at a satellite of the satellite radiotelephone communications system, and wherein the second satellite reception path is positioned at the same satellite. 11. A method according to claim 2, wherein the satellite radiotelephone communications system comprises a first satellite radiotelephone communications system, and wherein the second satellite reception path comprises a satellite of a second satellite radiotelephone communications system. 12. A method according to claim 11, wherein the second satellite reception path further comprises a terrestrial antenna configured to receive a feeder link transmission from the satellite of the second satellite radiotelephone communications system, and wherein the method further comprises conveying the second radio signal via the terrestrial antenna to the first satellite radiotelephone communications system. 13. A method according to claim 12, wherein the terrestrial antenna is coupled to a gateway of the second satellite radiotelephone communications system, and wherein the method further comprises conveying the second radio signal to the first satellite radiotelephone communications system via the gateway of the second satellite radiotelephone communications system. 14. A method according to claim 12, wherein the terrestrial antenna is coupled to a gateway of the first satellite radiotelephone communications system, and wherein the method further comprises conveying the second radio signal from the terrestrial antenna to the gateway of the first satellite radiotelephone communications system. 15. A method according to claim 1, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises applying the first and second radio signals to an adaptive signal processor. 16. A method according to claim 1, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises: applying the first and second radio signals to respective first and second transversal filters; combining outputs of the first and second transversal filters; and recovering the desired signal from the combined outputs. 17. A method according to claim 16, further comprising adjusting the first and second transversal filters responsive to the combined outputs. 18. A method according to claim 1, wherein receiving a second radio signal via a second satellite reception path comprises one or more of the following: receiving the second radio signal via a different satellite antenna spot beam than the first radio signal; receiving the second radio signal via a different satellite antenna than the first radio signal; receiving the second radio signal via a different satellite than the first radio signal; and receiving the second radio signal via a terrestrial antenna configured to receive feeder link transmissions from a satellite of a different satellite radiotelephone communications system. 19. A method according to claim 1, wherein the first and second satellite reception paths are configured to provide discrimination between the first and second sources based on a characteristic other than frequency. 20. A method of operating a satellite radiotelephone communications system, the method comprising: receiving first and second radio signals via respective first and second spot beams that serve respective first and second satellite cells of the satellite radiotelephone communications system, the first radio signal including a desired satellite uplink signal transmitted from a first source in the first satellite cell using a frequency assigned to the first satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the first satellite cell, the second radio signal including a measure of the interfering signal and/or a measure of the desired satellite uplink signal; and processing the first and second radio signals to recover the desired satellite uplink signal. 21. A method according to claim 20, wherein at least one radiating source in a region of the second satellite cell uses a frequency assigned to the first satellite cell for satellite and/or terrestrial communications. 22. A method according to claim 20, wherein the second satellite cell is adjacent a third satellite cell that uses a frequency assigned to the first satellite cell. 23. A method according to claim 20, wherein the second satellite cell overlaps or is adjacent a terrestrial cell that uses a frequency assigned to the first satellite cell. 24. A method according to claim 20, wherein the satellite radiotelephone communications system comprises a first satellite radiotelephone communications system, and wherein the second satellite cell overlaps or is adjacent a coverage area of a second satellite radiotelephone communications system. 25. A method according to claim 20, wherein the first and second spot beams are supported by respective first and second satellites of the satellite radiotelephone communications system. 26. A method according to claim 20, wherein the first and second spot beams are supported by the same satellite of the satellite radiotelephone communications system. 27. A method according to claim 20, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises applying the first and second radio signals to an adaptive signal processor. 28. A method according to claim 20, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises: applying the first and second radio signals to respective first and second transversal filters; combining outputs of the first and second transversal filters; and recovering the desired signal from the combined outputs. 29. A method according to claim 28, further comprising adjusting the first and second transversal filters responsive to the combined outputs. 30. A method of operating a first satellite radiotelephone communications system to reduce interference from a second satellite radiotelephone communications system, the method comprising: receiving a first radio signal via a first satellite reception path that serves a satellite cell of the first satellite radiotelephone communications system, the received first radio signal including a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source communicating with the second satellite radiotelephone communications system using the frequency assigned to the satellite cell; receiving a second radio signal via a second satellite reception path configured to preferentially receive transmissions from a coverage area of the second satellite communications system, the second radio signal including a measure of the interfering signal; and processing the first and second radio signals to recover the desired satellite uplink signal. 31. A method according to claim 30, wherein the first and second satellite reception paths are positioned at a satellite of the first satellite radiotelephone communications system. 32. A method according to claim 31, wherein the first and second satellite reception paths comprise respective first and second antennas positioned at the satellite of the first satellite radiotelephone communications system and configured such that the first and second antennas preferentially receive transmissions from respective first and second coverage areas of the first satellite radiotelephone communications system and the second satellite communications systems. 33. A method according to claim 30, wherein the first satellite reception path comprises a first antenna positioned at a satellite of the first satellite radiotelephone communications system, and wherein the second satellite reception path comprises a second antenna positioned at a satellite of the second satellite radiotelephone communications system. 34. A method according to claim 30, wherein the second satellite reception path comprises a terrestrial antenna configured to receive feeder link transmissions from a satellite of the second satellite radiotelephone communications system. 35. A method according to claim 30, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises applying the first and second radio signals to an adaptive signal processor. 36. A method according to claim 30, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises: applying the first and second radio signals to respective first and second transversal filters; combining outputs of the first and second transversal filters; and recovering the desired signal from the-combined outputs. 37. A method according to claim 36, further comprising adjusting the first and second transversal filters responsive to the combined outputs. 38. A method of operating a first satellite radiotelephone communications system to reduce interference from a second satellite communications system, the method comprising: receiving a first radio signal via a first satellite configured to preferentially receive transmissions from a coverage area of the first satellite radiotelephone communications system, the received first radio signal including a desired satellite uplink signal transmitted from a first source in the coverage area of the first satellite radiotelephone communications system and an interfering signal transmitted from at least one second source communicating with the second satellite communications system using at least one frequency of the desired satellite uplink signal; receiving a second radio signal via a second satellite configured to preferentially receive transmissions from a coverage area of the second satellite communications system, the second radio signal including a measure of the interfering signal; and processing the first and second radio signals to recover the desired satellite uplink signal. 39. A method according to claim 38, wherein receiving a second radio signal via a second satellite comprises receiving the second radio signal from the second satellite via a terrestrial antenna configured to receive feeder link transmissions from the second satellite. 40. A method according to claim 39, wherein receiving the second radio signal from the second satellite via a terrestrial antenna comprises receiving the second radio signal from the second satellite via the terrestrial antenna and a gateway of the second satellite communications system. 41. A method according to claim 38, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises applying the first and second radio signals to an adaptive signal processor. 42. A method according to claim 38, wherein processing the first and second radio signals to recover the desired satellite uplink signal comprises: applying the first and second radio signals to respective first and second transversal filters; combining outputs of the first and second transversal filters; and recovering the desired signal from the combined outputs. 43. A method according to claim 42, further comprising adjusting the first and second transversal filters responsive to the combined outputs. 44. A system comprising: a first satellite reception path that serves a satellite cell and that receives a first radio signal including a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the satellite cell; a second satellite reception path that receives a second radio signal including a measure of the interfering signal and/or the desired satellite uplink signal; and an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. 45. A system according to claim 44, wherein the second satellite reception path is configured to preferentially receive radio transmissions from an area outside of the satellite cell. 46. A system according to claim 45, wherein the area outside of the satellite cell comprises another satellite cell that uses the same frequency and/or a coverage area of another satellite communications system that uses the same frequency. 47. A system according to claim 45, wherein the first and second satellite reception paths comprise respective first and second spot beams that serve respective first and second satellite cells of a satellite radiotelephone communications system. 48. A system according to claim 47, wherein the second satellite cell uses a frequency assigned to the first satellite cell. 49. A system according to claim 47, wherein the second satellite cell is adjacent a third satellite cell that uses a frequency assigned to the first satellite cell. 50. A system according to claim 47, wherein the second satellite cell overlaps or is adjacent a terrestrial cell that uses a frequency assigned to the first satellite cell. 51. A system according to claim 47, wherein the satellite radiotelephone communications system comprises a first satellite radiotelephone communications system, and wherein the second satellite cell overlaps or is adjacent a coverage area of a second satellite radiotelephone communications system. 52. A system according to claim 45, wherein the first satellite reception path comprises a first satellite antenna positioned at a first satellite of a satellite radiotelephone communications system, and wherein the second satellite reception path comprises a second satellite antenna positioned at a second satellite of the satellite radiotelephone communications system. 53. A system according to claim 45, wherein the first satellite reception path comprises a first satellite antenna positioned at a satellite of a satellite radiotelephone communications system, and wherein the second satellite reception path is positioned at the same satellite. 54. A system according to claim 45, wherein the satellite cell comprises a satellite cell of a first satellite radiotelephone communications system, and wherein the second satellite reception path comprises a satellite cell of a second satellite radiotelephone communications system. 55. A system according to claim 54, wherein the second satellite reception path further comprises a terrestrial antenna configured to receive a feeder link transmission from the satellite of the second satellite radiotelephone communications system, and wherein the method further comprises conveying the second radio signal via the terrestrial antenna to the first satellite radiotelephone communications system. 56. A system according to claim 55, wherein the terrestrial antenna is coupled to a gateway of the second satellite radiotelephone communications system, and wherein the interference-suppressing signal processor receives the second radio signal to the first satellite radiotelephone communications system via the gateway of the second satellite radiotelephone communications system. 57. A system according to claim 55, wherein the terrestrial antenna is coupled to a gateway of the first satellite radiotelephone communications system, and wherein the interference-suppressing signal processor receives the second radio signal from the terrestrial antenna and the gateway of the first satellite radiotelephone communications system. 58. A system according to claim 44, wherein the interference-suppressing signal processor comprises an adaptive interference reducer. 59. A system according to claim 44, wherein the interference-suppressing signal processor comprises: first and second transversal filters that receive respective ones of the first and second radio signals; a combiner that combines outputs of the first and second transversal filters; and a detector that recovers the desired signal from the combined outputs. 60. A system according to claim 59, wherein the interference-suppressing signal processor further comprises a controller that adjusts the first and second transversal filters responsive to the combined outputs. 61. A system according to claim 44, wherein the first and second satellite reception paths are configured to provide discrimination between the first and second sources based on a characteristic other than frequency. 62. An apparatus comprising: an interference-suppressing signal processor configured to receive a first radio signal from a first satellite reception path that serves a satellite cell, the first radio signal including a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the satellite cell, to receive a second radio signal from a second satellite reception path that receives a second radio signal including a measure of the interfering signal, and to process the first and second radio signals to recover the desired satellite uplink signal. 63. An apparatus according to claim 62, wherein the interference-suppressing signal processor comprises an adaptive signal processor. 64. An apparatus according to claim 62, wherein the interference-suppressing signal processor comprises: first and second transversal filters that receive respective ones of the first and second radio signals; a combiner that combines outputs of the first and second transversal filters; and a detector that recovers the desired signal from the combined outputs. 65. A signal processor according to claim 64, wherein the interference-suppressing signal processor further comprises a controller that adjusts the first and second transversal filters responsive to the combined outputs. 66. A satellite radiotelephone communications system comprising: first and second spot beams that serve respective first and second satellite cells of the satellite radiotelephone communications system and that receive respective first and second radio signals, the first radio signal including a desired satellite uplink signal transmitted from a first source in the first satellite cell using a frequency assigned to the first satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the first satellite cell, the second radio signal including a measure of the interfering signal; and an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. 67. A system according to claim 66, wherein at least one radiating source in an area of the second satellite cell uses a frequency assigned to the first satellite cell to communicate terrestrially and/or with a satellite. 68. A system according to claim 66, wherein the second satellite cell is adjacent a third satellite cell that uses a frequency assigned to the first satellite cell. 69. A system according to claim 66, wherein the second satellite cell overlaps or is adjacent a terrestrial cell that uses a frequency assigned to the first satellite cell. 70. A system according to claim 66, wherein the satellite radiotelephone communications system comprises a first satellite radiotelephone communications system, and wherein the second satellite cell overlaps or is adjacent a coverage area of a second satellite radiotelephone communications system. 71. A system according to claim 66, wherein the first and second spot beams are supported by respective first and second satellites of the satellite radiotelephone communications system. 72. A system according to claim 66, wherein the first and second spot beams are supported by the same satellite of the satellite radiotelephone communications system. 73. A system according to claim 66, wherein the interference-suppressing signal processor comprises an adaptive signal processor. 74. A system according to claim 66, wherein the interference-suppressing signal processor comprises: first and second transversal filters that receive respective ones of the first and second radio signals; a combiner that combines outputs of the first and second transversal filters; and a detector that recovers the desired signal from the combined outputs. 75. A system according to claim 74, wherein the interference-suppressing signal processor further comprises a controller that adjusts the first and second transversal filters responsive to the combined outputs. 76. A system comprising: a first satellite reception path that serves a satellite cell of a first satellite radiotelephone communications system and receives a first radio signal therefrom, the received first radio signal including a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source communicating with a second satellite radiotelephone communications system using the frequency assigned to the satellite cell; a second satellite reception path that preferentially receives transmissions from a coverage area of the second satellite communications system and that receives a second radio signal including a measure of the interfering signal; and an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. 77. A system according to claim 76, wherein the first and second satellite reception paths are positioned at a satellite of the first satellite radiotelephone communications system. 78. A system according to claim 77, wherein the first and second satellite reception paths comprise respective first and second antennas positioned at a satellite of the first satellite radiotelephone communications system and configured such that the first and second antennas preferentially receive transmissions from respective first and second coverage areas of the first satellite radiotelephone communications system and the second satellite communications systems. 79. A system according to claim 76, wherein the first satellite reception path comprises a first antenna positioned at a satellite of the first satellite radiotelephone communications system, and wherein the second satellite reception path comprises a second antenna positioned at a satellite of the second satellite radiotelephone communications system. 80. A system according to claim 76, wherein the second satellite reception path comprises a terrestrial antenna configured to receive feeder link transmissions from a satellite of the second satellite radiotelephone communications system. 81. A system according to claim 76, wherein the interference-suppressing signal processor comprises an adaptive signal processor. 82. A system according to claim 76, wherein the interference-suppressing signal processor comprises: first and second transversal filters that receive respective ones of the first and second radio signals; a combiner that combines outputs of the first and second transversal filters; and a detector that recovers the desired signal from the combined outputs. 83. A system according to claim 82, wherein the interference-suppressing signal processor further comprises a controller that adjusts the first and second transversal filters responsive to the combined outputs. 84. A system comprising: a first satellite configured to preferentially receive transmissions from a coverage area of a first satellite radiotelephone communications system and that receives a first radio signal including a desired satellite uplink signal transmitted from a first source in the coverage area of the first satellite radiotelephone communications system using a frequency and an interfering signal transmitted from at least one second source communicating with a second satellite communications system using the frequency; a terrestrial antenna configured to receive feeder link transmissions from a second satellite configured to preferentially receive transmissions from a coverage area of the second satellite communications system and that receives a second radio signal including a measure of the interfering signal; and an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. 85. A system according to claim 84, wherein the interference-suppressing signal processor receives the second radio signal from the terrestrial antenna via a gateway of the second satellite communications system. 86. A system according to claim 84, wherein the interference-suppressing signal processor comprises an adaptive signal processor. 87. A system according to claim 84, wherein the interference-suppressing signal processor comprises: first and second transversal filters that receive respective ones of the first and second radio signals; a combiner that combines outputs of the first and second transversal filters; and a detector that recovers the desired signal from the combined outputs: 88. A system according to claim 87, wherein the interference-suppressing signal processor further comprises a controller that adjusts the first and second transversal filters responsive to the combined outputs. | RELATED APPLICATION The present application claims priority from U.S. Provisional Application Ser. No. 60/490,993, entitled Intra- and/or Inter-System Interference Reducing Systems and Methods for Satellite Communications Systems, filed Jul. 30, 2003 and incorporated herein by reference in its entirety. FIELD OF THE INVENTION This invention relates to wireless communications systems and methods, and more particularly to terrestrial and satellite communications systems and methods. BACKGROUND OF THE INVENTION Satellite communications systems and methods are widely used for communications. Satellite communications systems and methods generally employ at least one space-based component, such as one or more satellites, that is configured to communicate with at least one radioterminal. A satellite communications system or method may utilize a single antenna beam covering an entire area served by the system. Alternatively, in “cellular” satellite communications systems and methods, multiple beams are provided, each of which can serve substantially distinct geographical areas in the overall service region of the system, to collectively serve an overall satellite footprint. Thus, a cellular architecture similar to that used in conventional terrestrial cellular radiotelephone systems and methods can be implemented in cellular satellite-based systems and methods. The satellite typically communicates with radiotelephones over a bidirectional communications pathway, with radiotelephone communication signals being communicated from the satellite to the radiotelephone over a downlink or forward link, and from the radiotelephone to the satellite over an uplink or return link. The overall design and operation of cellular satellite radiotelephone systems and methods are well known to those having skill in the art, and need not be described further herein. Moreover, as used herein, the term “radiotelephone” includes cellular and/or satellite radiotelephones with or without a multi-line display; Personal Communications System (PCS) terminals that may combine a radiotelephone with data processing, facsimile and/or data communications capabilities; Personal Digital Assistants (PDA) that can include a radio frequency transceiver and a pager, Internet/intranet access, Web browser, organizer, calendar and/or a global positioning system (GPS) receiver; and/or conventional laptop and/or palmtop computers or other appliances, which include a radio frequency transceiver. As used herein, the term “radiotelephone” also includes any other radiating device/equipment/source that may have time-varying or fixed geographic coordinates, and may be portable, transportable, installed in a vehicle (aeronautical, maritime, or land-based), or situated and/or configured to operate locally and/or in a distributed fashion at any other location(s) on earth and/or in space. Radiotelephones may also be referred to herein as “radioterminals” or simply “terminals”. As is well known to those having skill in the art, terrestrial networks that are configured to reuse at least some of the frequencies of a satellite communications system can enhance satellite system availability, efficiency and/or economic viability. In particular, it is known that it may be difficult for satellite radiotelephone systems to reliably serve densely populated areas, because the satellite signal may be blocked by high-rise structures and/or may not penetrate into buildings. As a result, the satellite spectrum may be underutilized or unutilized in such areas. The use of terrestrial retransmission of at least some of the frequencies of the satellite system can reduce or eliminate this problem. Moreover, the capacity of an overall system (comprising space-based and terrestrial transmission of at least some of the frequencies allocated to the system) can be increased significantly by the introduction of terrestrial retransmission, since terrestrial frequency reuse can be much denser than that of a satellite-only system. In fact, capacity can be enhanced where it may be mostly needed, i.e., in densely populated urban/industrial/commercial areas. As a result, the overall system can become much more economically viable, as it may be able to serve a much larger subscriber base. Finally, satellite radiotelephones for a satellite radiotelephone system having a terrestrial component within the same satellite frequency band and using substantially the same air interface for both terrestrial and satellite communications can be more cost effective and/or aesthetically appealing. Conventional dual band/dual mode alternatives, such as the well known Thuraya, Iridium and/or Globalstar dual mode satellite/terrestrial radiotelephone systems, may duplicate some components, which may lead to increased cost, size and/or weight of the radiotelephone. U.S. Pat. No. 6,684,057, to coinventor Karabinis, and entitled Systems and Methods for Terrestrial Reuse of Cellular Satellite Frequency Spectrum, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein, describes that a satellite radiotelephone frequency can be reused terrestrially by an ancillary terrestrial network even within the same satellite cell, using interference cancellation techniques. In particular, the satellite radiotelephone system according to some embodiments of U.S. Pat. No. 6,684,057 includes a space-based component that is configured to receive wireless communications from a first radiotelephone in a satellite footprint over a satellite radiotelephone frequency band, and an ancillary terrestrial network that is configured to receive wireless. communications from a second radiotelephone in the satellite footprint over the satellite radiotelephone frequency band. The space-based component also receives the wireless communications from the second radiotelephone in the satellite footprint over the satellite radiotelephone frequency band as interference, along with the wireless communications that are received from the first radiotelephone in the satellite footprint over the satellite radiotelephone frequency band. An interference reducer is responsive to the space-based component and to the ancillary terrestrial network that is configured to reduce the interference from the wireless communications that are received by the space-based component from the first radiotelephone in the satellite footprint over the satellite radiotelephone frequency band, using the wireless communications that are received by the ancillary terrestrial network from the second radiotelephone in the satellite footprint over the satellite radiotelephone frequency band. U.S. Patent Application Publication No. 2003/0054761 A1, published Mar. 20, 2003 to coinventor Karabinis and entitled Spatial Guardbands for Terrestrial Reuse of Satellite Frequencies, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein, describes satellite radiotelephone systems that include a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band. The satellite footprint is divided into a plurality of satellite cells, in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused. An ancillary terrestrial network is configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is used in a satellite cell in the satellite footprint, outside the cell and in some embodiments separated therefrom by a spatial guardband. The spatial guardband may be sufficiently large to reduce or prevent interference between the at least one of the satellite radiotelephone frequencies that is used in the satellite cell in the satellite footprint, and the at least one of the satellite radiotelephone frequencies that is terrestrially reused outside the satellite cell and separated therefrom by the spatial guardband. The spatial guardband may be about half a radius of a satellite cell in width. SUMMARY OF THE INVENTION Some embodiments of the present invention allow two satellite and/or terrestrial communications systems to use the same frequency or frequencies for communications in geographically distinct, overlapping and/or congruent footprints while reducing interference in a given system (inter-system interference) that is caused by the same frequency signal(s) that is (are) used by the other system. In some embodiments, a satellite of a first satellite and/or terrestrial system includes a receive-only ancillary antenna that is configured to receive signals, occupying at least some of the frequencies of the first satellite and/or terrestrial system, from the second satellite and/or terrestrial system footprint. The received signal(s) from the ancillary antenna can be used to reduce interference to the first satellite and/or terrestrial system by the second satellite and/or terrestrial system. In other embodiments, at least some of the signals from the second satellite and/or terrestrial communications system that have occupied and/or are occupying at least some of the frequencies of the first satellite and/or terrestrial communications system are routed by a gateway and/or other component(s) of the first and/or second satellite and/or terrestrial system, before or after regeneration, to a gateway and/or other component(s) of the first satellite and/or terrestrial system. The routed signals may then be used to improve a signal-to-interference and/or -noise measure of a desired signal and for interference reduction of a desired signal. Finally, other embodiments need not use a separate ancillary (receive-only) antenna or inter-system routing to reduce interference. Rather, in a given satellite and/or terrestrial communications system, a desired signal plus interference received by a given satellite cell of a satellite over one or more frequencies, and received signals from at least one adjacent and/or non-adjacent satellite cells of the satellite, received over the one or more frequencies, are provided to a signal processor (interference reducer) that may include a plurality of transversal filters and a control mechanism that is used to adjust coefficients of the transversal filters. The signal processor (interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. Accordingly, these embodiments of the present invention allow two separate satellite and/or terrestrial communications systems to share at least some frequencies, while reducing or minimizing potential interference. Other embodiments of the present invention can use a signal processor (interference reducer), that may include a plurality of transversal filters and a control mechanism, to reduce interference within the satellite and/or terrestrial radiotelephone system (intra-system interference) that is caused by terrestrial reuse and/or intra-satellite system reuse of one or more frequencies that may also be used for space-based communications by a given satellite cell, and/or to improve a signal-to-interference and/or -noise measure of a desired signal of the given satellite cell. In some embodiments, the signals that are received at the satellite by a given satellite cell over a given frequency or frequencies, and the signals that are received at the satellite by adjacent and/or non-adjacent satellite cells over the given frequency or frequencies, are provided to a signal processor (interference reducer), to reduce and/or eliminate interference from one or more ancillary terrestrial components and/or intra-satellite frequency reuse that also use the given frequency or frequencies for terrestrial wireless and/or satellite communications. In other embodiments, signals at the given frequency or frequencies that are received from adjacent and/or non-adjacent satellite cells that do not reuse the given frequency or frequencies for satellite communications, also are provided to the signal processor (interference reducer) to reduce or eliminate interference by the terrestrial reuse of the frequency or frequencies by the same or another system and/or to improve a signal-to-interference and/or -noise measure of a desired signal. The signal processor (interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. Yet other embodiments of the present invention can combine the embodiments that were described above to provide both inter- and intra-system interference reduction, minimization and/or cancellation. Accordingly, inter- and/or intra-system interference from terrestrial- and/or space-based reuse of radiotelephone frequencies can be reduced, minimized or eliminated. In some embodiments of the present invention, methods of operating a satellite and/or terrestrial radiotelephone communications system are provided. A first radio signal is received via a first satellite reception path, for example, an antenna or spot beam, which serves a satellite cell. The received first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to the satellite cell. A second radio signal is received via a second satellite reception path, for example, via another antenna (ground- and/or space-based) or spot beam of the system and/or via a satellite and/or terrestrial infrastructure of another satellite and/or terrestrial communications system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed mathematically (software) and/or by an electronic circuit (hardware) to recover at least one measure of the desired satellite uplink signal. In further embodiments, the second satellite reception path may be configured to preferentially receive radio transmissions from an area outside of the satellite cell. For example, the area outside of the satellite cell may include another satellite cell that uses at least one of the frequencies assigned to and/or used by the satellite cell and/or a coverage area of another satellite and/or terrestrial communications system that uses at least one of the frequencies assigned to and/or used by the satellite cell. In some embodiments of the present invention, the first and second satellite reception paths may include respective first and second spot beams that serve respective first and second satellite cells of the satellite and/or terrestrial radiotelephone communications system. The second satellite cell may use a frequency or frequencies assigned to and/or used by the first satellite cell, may be adjacent a third satellite cell that uses a frequency or frequencies assigned to and/or used by the first satellite cell, may overlap or be adjacent a terrestrial cell and/or area that uses a frequency or frequencies assigned to and/or used by the first satellite cell and/or may overlap or be adjacent a coverage area of a second satellite and/or terrestrial radiotelephone communications system that uses a frequency or frequencies assigned to and/or used by the first satellite cell. According to some embodiments, the first satellite reception path includes a first satellite antenna positioned at a first satellite of the satellite and/or terrestrial radiotelephone communications system, and the second satellite reception path includes a second satellite antenna positioned at a second satellite of the satellite and/or terrestrial radiotelephone communications system. In other embodiments, the first satellite reception path may include a first satellite antenna positioned at a satellite of the satellite and/or terrestrial radiotelephone communications system, and the second satellite reception path may include a second and/or the first satellite antenna positioned at the same satellite. In yet further embodiments, the second satellite reception path may include a satellite of a second satellite and/or terrestrial radiotelephone communications system. The second satellite reception path may further include a terrestrial antenna configured to receive a feeder link transmission from the satellite of the second satellite and/or terrestrial radiotelephone communications system, and the second radio signal may be conveyed to the first and/or second satellite and/or terrestrial radiotelephone communications system via the terrestrial antenna. The terrestrial antenna may be coupled to a gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system, and the second radio signal may be conveyed to the first satellite and/or terrestrial radiotelephone communications system via the gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system. The terrestrial antenna may be coupled to a gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system, e.g., directly or through other elements of the first and/or second system, and the second radio signal may be conveyed from the terrestrial antenna to the gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system. According to other aspects of the present invention, the first and second radio signals may be applied to a signal processor (interference reducer) comprising respective first and second transversal filters. Outputs of the first and second transversal filters may be combined, and at least one measure of the desired signal may be recovered from the combined outputs. The first and second transversal filters may be adjusted responsive to a measure of the combined outputs and/or a measure of the first and/or second radio signals. The signal processor (interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. According to other aspects of the present invention, first and second radio signals are received via respective first and second spot beams that serve respective first and second satellite cells of the satellite and/or terrestrial radiotelephone communications system. The first radio signal includes a desired satellite uplink signal transmitted from a first source in the first satellite cell using a frequency or frequencies assigned to the first satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to and/or used by the first satellite cell, and the second radio signal includes a measure of the interfering signal. The first and second radio signals are processed using, for example, an adaptive signal processor (adaptive interference reducer), to improve a signal-to-interference and/or -noise measure of the desired satellite uplink signal and recover the desired satellite uplink signal. The adaptive signal processor (adaptive interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. In additional embodiments of the present invention, a first radio signal is received via a first satellite reception path that serves a satellite cell of the first satellite and/or terrestrial radiotelephone communications system. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source communicating with the second satellite and/or terrestrial radiotelephone communications system using at least one frequency assigned to and/or used by the satellite cell. A second radio signal is received via a second satellite reception path configured to preferentially receive transmissions from a coverage area of the second satellite and/or terrestrial communications system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed to recover the desired satellite uplink signal. According to some embodiments of the present invention, methods of operating a first satellite and/or terrestrial radiotelephone communications system to reduce interference from a second satellite and/or terrestrial communications system are provided. A first radio signal is received via a first satellite configured to preferentially receive transmissions from a coverage area of the first satellite and/or terrestrial radiotelephone communications system. The first radio signal includes a desired satellite uplink signal transmitted from a first source in the coverage area of the first satellite and/or terrestrial radiotelephone communications system and an interfering signal transmitted from at least one second source communicating with the second satellite and/or terrestrial communications system using at least one frequency of the first signal. A second radio signal is received via a second satellite and/or terrestrial antenna configured to preferentially receive transmissions from a coverage area of the second satellite and/or terrestrial communications system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed to recover the desired satellite uplink signal. The second radio signal may be received from the second satellite via a terrestrial antenna configured to receive feeder link transmissions from the second satellite. In some system embodiments of the present invention, a system includes a first satellite reception path that serves a satellite cell and that receives a first radio signal. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to and/or used by the satellite cell. The system further includes a second satellite reception path that receives a second radio signal including a measure of the interfering signal. The system also includes an interference-suppressing signal processor that processes the first and second radio signals to recover at least one measure and/or at least one element of the desired satellite uplink signal. The interference-suppressing signal processor may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. In further embodiments of the present invention, an apparatus includes an interference-suppressing signal processor configured to receive a first radio signal from a first satellite reception path that serves a satellite cell. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to and/or used by the satellite cell. The interference-suppressing signal processor is further configured to receive a second radio signal from a second satellite reception path that receives a second radio signal including a measure of the interfering signal, and to process the first and second radio signals to recover at least one measure and/or at least one element of the desired satellite uplink signal. The interference-suppressing signal processor may include an adaptive interference reducer. The interference-suppressing signal processor may include first and second transversal filters that receive respective ones of the first and second radio signals, a combiner that combines outputs of the first and second transversal filters, and a detector that recovers at least one measure and/or element of the desired signal from the combined outputs. The interference-suppressing signal processor may further include a controller that adjusts the first and second transversal filters responsive to a measure of the combined outputs and/or a measure of the first and/or second radio signals. The interference suppressing signal processor and/or the interference reducer may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. According to additional embodiments of the present invention, a satellite and/or terrestrial radiotelephone communications system includes first and second spot beams that serve respective first and second satellite cells of the satellite and/or terrestrial radiotelephone communications system and that receive respective first and second radio signals. The first radio signal includes a desired satellite uplink signal transmitted from a first source in the first satellite cell using a frequency or frequencies assigned to the first satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to the first satellite cell. The second radio signal includes a measure of the interfering signal. The system further includes an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. In yet further embodiments of the present invention, a system includes a first satellite reception path that serves a satellite cell of a first satellite and/or terrestrial radiotelephone communications system and receives a first radio signal therefrom. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source communicating with a second satellite and/or terrestrial radiotelephone communications system using at least one frequency assigned to the satellite cell. The system also includes a second satellite reception path that preferentially receives transmissions from a coverage area of the second satellite and/or terrestrial communications system and that receives a second radio signal including a measure of the interfering signal. The system further includes an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. In additional embodiments, a system includes a first satellite configured to preferentially receive transmissions from a coverage area of a first satellite and/or terrestrial radiotelephone communications system and that receives a first radio signal including a desired satellite uplink signal transmitted from a first source in the coverage area of the first satellite and/or terrestrial radiotelephone communications system using a frequency or frequencies and an interfering signal transmitted from at least one second source communicating with a second satellite and/or terrestrial communications system using the frequency or at least one of the frequencies. The system also includes a terrestrial antenna configured to receive feeder link transmissions from a second satellite configured to preferentially receive transmissions from a coverage area of the second satellite and/or terrestrial communications system and that receives a second radio signal including a measure of the interfering signal. The system further includes an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a satellite communications system and operations thereof according to some embodiments of the present invention. FIG. 2 is a cell layout diagram illustrating exemplary operations of a satellite communications system according to further embodiments of the present invention. FIG. 3 is a schematic diagram of an interference-suppressing signal processor according to some embodiments of the present invention. FIGS. 4, 5, and 6 are schematic diagrams illustrating satellite communications systems and operations thereof according to additional embodiments of the present invention. DETAILED DESCRIPTION Specific exemplary embodiments of the invention now will be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Furthermore, “connected” or “coupled” as used herein may include wirelessly connected or coupled. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items. The symbol “/” is also used as a shorthand notation for “and/or”. As used herein the term “measure” of a given signal includes any parameter and/or any measurable and/or calculable quantity (irrespective of any measurement and/or calculation error or inaccuracy); and/or signal that is related to, derived from, and/or generated (via natural and/or man-made processes) from the given signal. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes,” “comprises,” “including” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Some embodiments of the present invention described herein involve the use of diverse satellite reception paths to receive desired satellite uplink signals and one or more interfering signals. As used herein, a “satellite reception path” generally refers to one or more elements that are configured to receive and convey satellite-received signals, i.e., signals that impinge upon a satellite from, for example, terrestrially positioned sources, such as radiotelephones. Accordingly, a satellite reception path may include, but is not limited to, a satellite antenna, a spot beam supported by a satellite antenna, electronic circuitry (hardware and/or software) that receives, processes, and transports signals received by a satellite antenna, and terrestrially-based antennas and hardware and/or software that receive and/or process a satellite-received signal via, for example, a satellite relay mechanism. As used herein, a “radio signal” received by such a satellite reception path may include a radio-frequency carrier modulated signal transmitted by a source and/or data, voice or other signals combined with or embedded in such a radio-frequency signal. Some embodiments of the present invention will be described herein relative to first and second satellite radiotelephone communications systems. For convenience, the first satellite radiotelephone communications system, and components thereof, may be referred to as “MSV” and may, in some embodiments, correspond to a satellite radiotelephone system provided by Mobile Satellite Ventures, LP, the assignee of the present invention. The second satellite radiotelephone system and/or components thereof may be referred to as “non-MSV.” However, it will be understood that the invention is not limited to applications involving combinations of MSV and non-MSV systems, and that any first and second satellite radiotelephone communications systems may be encompassed by the designations MSV and non-MSV. FIG. 1 illustrates a satellite 100 that is configured with two antennas 110, 120 according to some embodiments of the present invention. The antennas 110, 120 of the satellite 100 may be of different sizes (in the illustrated embodiments, 26 meters and 9 meters, respectively) and may be directed toward different service footprints 130, 140. The service footprints may be disjoint (as is illustrated in FIG. 1), may have some overlap, or be fully overlapping. Specifically, FIG. 1 shows the larger one 110 of the two satellite antennas 110, 120 operative directed toward an area 130 labeled “MSV service footprint”, while the smaller antenna 120, also referred to herein as an ancillary antenna, is operative directed toward an area 140 labeled “non-MSV service footprint.” The smaller antenna 120 may be configured to operate as a receive-only antenna. The larger antenna 110 may be configured to receive and transmit. Each antenna 110, 120 may be configured to form a plurality of spot beams (cells) over its respective footprint or area. In some embodiments antennas 110 and 120 may have identical or substantially identical size. In other embodiments, antenna 120 may be larger or smaller than antenna 110. Satellite terminal transmissions 142 that may be intended for a non-MSV satellite (such as, for example, an Inmarsat satellite) may also be intercepted (intentionally or unintentionally) by at least one MSV satellite. At least some satellite terminal transmissions by non-MSV satellite terminals may be co-channel, or partially co-channel, and/or co-frequency, or partially co-frequency, with at least some of MSV's satellite terminal transmissions. Thus, at least some satellite terminal transmissions by non-MSV satellite terminals that may be intended for a non-MSV satellite and are co-channel, or partially co-channel, and/or co-frequency, or partially co-frequency, with at least some satellite terminal transmissions 132 of MSV's satellite terminals (that may be intended for MSV's satellite(s)) may cause interference to at least some receivers of MSV's satellite(s) and/or ground infrastructure (satellite gateway(s)). According to some embodiments of the present invention, systems and methods are provided that are capable of adaptively mitigating the effects of inter-system co-channel and/or co-frequency interference in order to allow improved communications performance and also to potentially facilitate more efficient reuse of radio frequency resources between systems. At least one ancillary antenna on an MSV satellite (for example, the smaller antenna 120 on the MSV satellite of FIG. 1) may be operative configured and/or positioned, physically and/or electronically, to maximize a reception of emissions by non-MSV satellite terminal(s) that are intended for a non-MSV satellite. This antenna, thus configured and/or positioned, may receive substantially strong interference signals that may be used at an MSV infrastructure element (such as a satellite gateway) and/or at an MSV satellite to mitigate (reduce, suppress or substantially eliminate) interference signals that may be received by an MSV satellite antenna (such as the MSV satellite antenna 110 of FIG. 1) whose mission may be to provide communications service to at least one MSV user terminal over at least some portion of an MSV service area 130. Still referring to FIG. 1, an Ancillary Terrestrial Network (ATN) comprising a plurality of Ancillary Terrestrial Components (ATCs) and ATC radioterminals may be deployed over certain areas of MSV's service footprint 130. An ATC comprises one or more radiating infrastructure elements, such as a base station with associated infrastructure. At least one radioterminal may communicate with the at least one radiating infrastructure element. Signals 134 that are radiated by an ATC and/or ATC radioterminal(s) may be intercepted by MSV's satellite(s) 100, causing additional interference. According to some embodiments of the present invention, the Space Based Network (SBN), including a Space Based Component (SBC) (e.g., at least one satellite) and ground infrastructure (e.g., at least one gateway), includes systems and/or methods for adaptively mitigating interference received from at least certain elements of the ATN that may be reusing at least one frequency of the SBN (intra-system frequency reuse) to provide terrestrial communications. According to other embodiments of the present invention, the SBN also includes systems and/or methods that are capable of adaptively mitigating interference caused by intra-system frequency reuse by the SBN to provide satellite communications. FIG. 2 illustrates an example of intra-system frequency reuse. As is illustrated in FIG. 2, a given frequency set (comprising one or more frequencies), frequency set 1 for example, may be used and reused for satellite communications by the SBN over at least a portion of a system's footprint in accordance with, for example, a seven-cell frequency reuse pattern, as illustrated in FIG. 2. A given satellite cell, such as satellite cell S, configured to receive at least one frequency of frequency set 1 from at least one radioterminal that is operative over a footprint of satellite cell S, may also receive interference from other intra-system terminal emissions intended, for example, for satellite cells T through Y, that may include at least some of the same frequencies being radiated by the at least one radioterminal that is operative over the footprint of satellite cell S. FIG. 2 also illustrates the location of two ATCs, labeled as A and B, which may also be reusing all or some of the frequencies of frequency set 1 to communicate terrestrially with ATC radioterminals. Thus, ATC emissions of ATC A and/or B (and/or other ATCs) and/or the radioterminals thereof may also cause interference to one or more receivers associated with satellite cell S and/or other satellite cells. Spatial guardbands, as described in the above-cited U.S. Patent Application Publication No. 2003/0054761 A1, are shown by the unshaded rings of FIG. 2. Referring to FIGS. 1 and 2 and to the satellite antenna 110 that is serving MSV's service footprint 130 (see FIG. 1), at least some signals of at least some of the neighboring and/or non-neighboring satellite cells of a given satellite cell, such as satellite cell S, may be correlated to some degree with at least some components of an interference of the given satellite cell (such as satellite cell S). Such signals may be transported to, for example, a satellite gateway via a satellite feeder link, such as the satellite feeder link 101 and/or 102 of FIG. 1, to serve as inputs to an interference suppressor. In addition, at least some signals of at least some of the neighboring satellite cells of a given satellite cell, such as satellite cell S, may be correlated to a degree with at least one component of a desired signal of the given satellite cell (such as satellite cell S). Such signals of the neighboring satellite cells that are correlated to a degree with the at least one component of the desired signal of the given satellite cell may, in some embodiments, be transported to, for example, a satellite gateway via a satellite feeder link, such as the satellite feeder link 101 and/or 102 of FIG. 1, to serve as inputs to a signal processor, that may also be an interference suppressor, to improve a desired signal-to-interference measure at-an output of the signal processor and/or the interference suppressor. Relative to the satellite antenna 120 that is operatively directed toward the non-MSV service footprint 140, at least some of its received signals that may be used to suppress interference received by the satellite antenna 110 serving the MSV footprint 130, may be transported to, for example, an MSV satellite gateway via a satellite feeder link, such as the satellite feeder link 101 and/or 102 of FIG. 1. The two satellite feeder links 101, 102 illustrated in FIG. 1 may use different frequencies and/or different frequency bands to transmit information to the ground to two or more spatially proximate or spatially distant receive antennas or to a single antenna. In some embodiments, the information transported to the ground (i.e., to a satellite gateway) by the feeder links 101, 102 illustrated in FIG. 1 may be accommodated by a single feeder link using the frequencies of a single frequency band. In other embodiments, a satellite may be configured with two or more feeder links, using the frequencies of one or more frequency bands, to transport information from a satellite to at least one ground facility (i.e., a satellite gateway) via a single, spatially distant, and/or spatially proximate feeder link receive antennas on the ground. FIG. 3 illustrates an adaptive receiver 300 (also referred to as an adaptive interference reducer or an adaptive signal processor), that may be configured at a satellite gateway, at a satellite, and/or at any other location or locations (distributed functionality), to suppress interference that may be generated by intra- and/or inter-system frequency reuse. Specifically, the receiver architecture of FIG. 3 is shown operative to suppress interference that may be at least partially co-channel and/or co-frequency with a given “desired signal” received by a satellite cell such as satellite cell S of FIG. 2. The receiver 300 depicted in FIG. 3 combines (in a combiner 320), in accordance with a control law or performance index (of a controller 340), such as a Least Mean Squared Error (LMSE) control law or performance index, via a plurality of (fractionally- and/or synchronously-spaced, feed-forward and/or decision-feedback) transversal filters 310, a plurality of signal inputs from a plurality of satellite cells that may be formed by one or more satellite antennas and/or satellites, to form a decision variable for recovering a desired signal in a detector 330. Those skilled in the art will recognize that different control laws (other than LMSE), such as zero-forcing, may be used to form and/or update the transversal filter coefficients. Those skilled in the art will also recognize that different control law input signals may be required by the different control laws to derive update information for the plurality of transversal filter coefficients. For example, in accordance with the zero-forcing control law, the error quantity (see FIG. 3) and the output of the decision stage 330 of FIG. 3 may serve as inputs to the control law 340. It will also be recognized by those of skill in the art that the number of transversal filter coefficients per transversal filter 310 need not be the same over the ensemble of transversal filters depicted in FIG. 3. Some transversal filters may, for example, have seven (7) coefficients or taps, while others may have five (5) or only three (3) and some transversal filters may be limited to a single coefficient. In some embodiments, at least one transversal filter of the ensemble of transversal filters depicted in FIG. 3 may be deleted and the corresponding input signal may be provided directly to summing junction 320. In some embodiments, all transversal filters have an identical number of coefficients or taps (greater than or equal to one). Furthermore, in some embodiments, the architecture and/or control law associated with each transversal filter of the ensemble of transversal filters of FIG. 3 may not be the same for all transversal filters of the ensemble. For example, some transversal filters may be synchronously-spaced and operative based on a zero-forcing control law, others fractionally-spaced and operative based on a least mean-squared error control law, and others decision-feedback with either synchronously- or fractionally-spaced feed-forward sections operative on various combinations of control laws and/or performance measures. Referring again to FIG. 3, it is seen that the top (first) transversal filter input labeled “signal of satellite cell S” denotes a desired signal plus interference, as received by satellite cell S (see FIG. 2). The transversal filter inputs T through Y represent signals that may be correlated to some degree with the interference of the desired signal that is due to intra-satellite system (SBN) frequency reuse. The transversal filter inputs T through Y represent signals from adjacent satellite system cells that use the same frequency or frequencies as satellite cell S. It will be understood that non-adjacent satellite cells that use the same frequency or frequencies as satellite cell S, shown by some or all of the cross-hatched cells other than cells S-Y, may also be provided to transversal filters of receiver 300. The transversal filter inputs A3, A5, A7 and B6, B7, B4 of receiver 300 of FIG. 3 represent signals that are generated by transmissions of ATC A and B and/or the radioterminals thereof, respectively, that may be correlated with, at least some, interference components of the desired signal of satellite cell S. Fewer or more A and/or B signals and a correspondingly fewer or more transversal filters than the numbers shown in FIG. 3 may be provided in some embodiments. In particular, in FIG. 3, the signals from the three adjacent cells to an ATC that is terrestrially reusing the same frequency or frequencies as satellite cell S are provided. Thus, for ATC A, the signals from satellite cells 3, 5 and 7 are provided as inputs, and for ATC B, the signals from satellite cells 4, 6 and 7 are provided. In other embodiments, signals from non-adjacent satellite cells also may be provided. The transversal filter inputs I1 through IN provide signals from the smaller antenna of FIG. 1, that may be correlated with at least one interference component of the desired signal of satellite cell S that may be due to inter-system frequency reuse. It is understood that, in general, all transversal filter input signals shown in FIG. 3 may provide both interference and desired signal components. In some embodiments, the number of antenna(s) of a satellite that may be directed toward another satellite radiotelephone system service footprint may be reduced or eliminated. Thus, in some embodiments, the small antenna of the satellite of FIG. 1 may be eliminated. In such embodiments, the transversal filter inputs I1 through IN of FIG. 3 may be replaced with signals derived from the co-system (intra-system) satellite antenna cell patterns. Thus, some embodiments of the present invention can use an adaptive interference reducer to reduce, minimize or eliminate intra- and/or inter-system interference by providing as input signals for a plurality of transversal filters, signals of a given satellite cell (such as S) and adjacent satellite cells (such as T-Y) that reuse one or more frequencies of the given satellite cell (such as S). Thus, in some embodiments, input signals from satellite cells S-Y may be used as inputs to an adaptive interference reducer, to reduce interference from co-frequency intra-system reuse. Other embodiments of the present invention can add one or more of the following groups of signals as inputs to an adaptive interference reducer, to further reduce interference and/or improve a signal-to-interference measure of a desired signal: (1) Signals from non-adjacent cells, such as one or more cross-hatched cells 1 of FIG. 2, other than cells S-Y that reuse one or more frequencies of the given satellite cell S; (2) Signals from satellite cells that contain over a geographic footprint an ATC which is terrestrially reusing at least one of the satellite frequencies as the given satellite cell, such as satellite cell 6 that contains ATC B therein, or satellite cells 3, 7 and 5, that contain ATC A therein; (3) Signals from satellite cells that are immediately adjacent a cell described in (2) above; (4) Signals from satellite cells that are remote from the satellite cells described in (2) above; (5) Signals from an ancillary antenna at the satellite that is pointed at the satellite footprint of another satellite system that reuses at least one of the frequencies of the given satellite cell S, for example, input signals I1-IN of FIG. 3; (6) Signals from a second satellite in the given satellite radiotelephone system, that receives at least one of the frequencies of the given cell, if the space based network includes multiple satellites, as shown in FIG. 3 by the dashed box labeled “Input signals from second satellite”; (7) Signals from another satellite radiotelephone system that reuses at least one of the frequencies of satellite cell S that may be provided, for example, by a gateway and/or other component of the other and/or same satellite radiotelephone system; and/or (8) Signals from cells adjacent to satellite cell S. Sub-combinations and combinations of these input signals also may be provided to the adaptive interference reducer. Further embodiments of the present invention are illustrated in FIG. 4. As shown, a system 400 includes a first and second satellite reception paths 410, 420. The first satellite reception path 410 serves a satellite cell 442 of a coverage area 440 of a satellite radiotelephone communications system (e.g., the MSV system of FIG. 1). It will be appreciated that the first satellite reception path 410 may include, for example, a spot beam of a satellite (e.g., the satellite 100 of FIG. 1), along with other components for conveying satellite-received signals. The first satellite reception path 410 receives a first signal including a desired signal 455 transmitted by a source 450 (e.g., a satellite terminal) and an interfering signal transmitted by a second source, which may include, for example, an interfering signal 465a transmitted by a source 460a within the coverage area 440 (e.g., another satellite terminal and/or an ATC) and/or an interfering signal 465b transmitted by a source 460b positioned outside of the coverage area (e.g., in a coverage area 470 of a second satellite communications system). The signals received by the first and second satellite reception paths 410, 420 are provided to an interference-suppressing signal processor 430, which processes the received signals to recover the desired signal 455. The signal processor 430 may include, for example, an adaptive interference reducer along the lines described above with reference to FIG. 3. In further embodiments of the present invention, inter-system interference may be suppressed using a satellite reception path that is responsive to elements of an interfering satellite communications system. For example, as shown in FIG. 5, interference in a first satellite radiotelephone communications system 510 introduced by an adjacent or overlapping second satellite communications system 520 may be reduced by capturing feeder downlink signals 524 that include information on interfering signals generated by users and/or components of the interfering system 520. In particular, the first satellite radiotelephone communications system 510 includes at least one satellite 511 that supports a satellite reception path that includes a spot beam 514 that serves a satellite cell 513. The spot beam 514 receives a signal including a desired signal 515 transmitted by a terminal in the cell 513 and an interfering signal 523 transmitted using the same frequency by a source, e.g., at least one terminal, that is in communication with a satellite 521 and/or an ATN of the second system 520. The satellite 521 of the second system 520 receives a signal that also includes a measure of the interfering signal 523. As shown, the first system 510 includes a gateway 518 served by a terrestrial antenna 517 that receives a feeder downlink signal 516 from the satellite 511. It will be appreciated that the feeder downlink signal 516 includes the signal received by the spot beam 514. The second system 520 similarly includes a gateway 526 that is served by a terrestrial antenna 525 that receives a feeder downlink signal 524 from the satellite 521. It will be further appreciated that the feeder downlink signal 524 includes a measure of the terrestrially generated interfering signal 523 received by the satellite 511. The signal received by the satellite 521 of the second system 520 is conveyed from the gateway 526 of the second system 520 to the gateway 518 of the first system 510. The gateway 518 of the first system 510 may include an interference reducer (IR) 519 that is configured to process the signals received by the first and second satellites 511, 521 to recover the desired signal 515. The recovered signal 515 may be conveyed on to other network components 530, such as telephony network components (switches, routers, etc.) and/or ATN components. It will be appreciated that the IR 519 may receive other signal inputs that provide information and/or measure(s) on interference signals, for example, signal inputs from other spot beams, satellites and/or ancillary antennas along the lines described above with reference to FIGS. 1-3. Referring to FIG. 6, in other embodiments of the present invention, for example, in applications in which signals generated in conjunction with an interfering system are not directly available from the interfering system, an interfering signal may be obtained by directly capturing a downlink feeder signal transmitted by the interfering system. For example, as illustrated in FIG. 6, in addition to a terrestrial antenna 517a configured to receive downlink feeder signals 516 transmitted by the satellite 511 of the first system 510, a terrestrial antenna 517b may be coupled to the gateway 518 of the first system 510 and configured to receive the downlink feeder signal 524 of the interfering second system 520. It will be appreciated that the first and second antennas 517a, 517b may be physically separate antennas and/or spatially diverse antenna beams supported by a single antenna structure and/or, for example, a beamforming network. It will be appreciated that the terrestrial antenna 517b may be coupled to the first system 510 in any of a number of different ways. It will be further appreciated that the IR 519 may be positioned in a different component of the first system 510, and may be distributed among multiple components of the first system 510. In the drawings and specification, there have been disclosed exemplary embodiments of the invention. Although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Satellite communications systems and methods are widely used for communications. Satellite communications systems and methods generally employ at least one space-based component, such as one or more satellites, that is configured to communicate with at least one radioterminal. A satellite communications system or method may utilize a single antenna beam covering an entire area served by the system. Alternatively, in “cellular” satellite communications systems and methods, multiple beams are provided, each of which can serve substantially distinct geographical areas in the overall service region of the system, to collectively serve an overall satellite footprint. Thus, a cellular architecture similar to that used in conventional terrestrial cellular radiotelephone systems and methods can be implemented in cellular satellite-based systems and methods. The satellite typically communicates with radiotelephones over a bidirectional communications pathway, with radiotelephone communication signals being communicated from the satellite to the radiotelephone over a downlink or forward link, and from the radiotelephone to the satellite over an uplink or return link. The overall design and operation of cellular satellite radiotelephone systems and methods are well known to those having skill in the art, and need not be described further herein. Moreover, as used herein, the term “radiotelephone” includes cellular and/or satellite radiotelephones with or without a multi-line display; Personal Communications System (PCS) terminals that may combine a radiotelephone with data processing, facsimile and/or data communications capabilities; Personal Digital Assistants (PDA) that can include a radio frequency transceiver and a pager, Internet/intranet access, Web browser, organizer, calendar and/or a global positioning system (GPS) receiver; and/or conventional laptop and/or palmtop computers or other appliances, which include a radio frequency transceiver. As used herein, the term “radiotelephone” also includes any other radiating device/equipment/source that may have time-varying or fixed geographic coordinates, and may be portable, transportable, installed in a vehicle (aeronautical, maritime, or land-based), or situated and/or configured to operate locally and/or in a distributed fashion at any other location(s) on earth and/or in space. Radiotelephones may also be referred to herein as “radioterminals” or simply “terminals”. As is well known to those having skill in the art, terrestrial networks that are configured to reuse at least some of the frequencies of a satellite communications system can enhance satellite system availability, efficiency and/or economic viability. In particular, it is known that it may be difficult for satellite radiotelephone systems to reliably serve densely populated areas, because the satellite signal may be blocked by high-rise structures and/or may not penetrate into buildings. As a result, the satellite spectrum may be underutilized or unutilized in such areas. The use of terrestrial retransmission of at least some of the frequencies of the satellite system can reduce or eliminate this problem. Moreover, the capacity of an overall system (comprising space-based and terrestrial transmission of at least some of the frequencies allocated to the system) can be increased significantly by the introduction of terrestrial retransmission, since terrestrial frequency reuse can be much denser than that of a satellite-only system. In fact, capacity can be enhanced where it may be mostly needed, i.e., in densely populated urban/industrial/commercial areas. As a result, the overall system can become much more economically viable, as it may be able to serve a much larger subscriber base. Finally, satellite radiotelephones for a satellite radiotelephone system having a terrestrial component within the same satellite frequency band and using substantially the same air interface for both terrestrial and satellite communications can be more cost effective and/or aesthetically appealing. Conventional dual band/dual mode alternatives, such as the well known Thuraya, Iridium and/or Globalstar dual mode satellite/terrestrial radiotelephone systems, may duplicate some components, which may lead to increased cost, size and/or weight of the radiotelephone. U.S. Pat. No. 6,684,057, to coinventor Karabinis, and entitled Systems and Methods for Terrestrial Reuse of Cellular Satellite Frequency Spectrum , the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein, describes that a satellite radiotelephone frequency can be reused terrestrially by an ancillary terrestrial network even within the same satellite cell, using interference cancellation techniques. In particular, the satellite radiotelephone system according to some embodiments of U.S. Pat. No. 6,684,057 includes a space-based component that is configured to receive wireless communications from a first radiotelephone in a satellite footprint over a satellite radiotelephone frequency band, and an ancillary terrestrial network that is configured to receive wireless. communications from a second radiotelephone in the satellite footprint over the satellite radiotelephone frequency band. The space-based component also receives the wireless communications from the second radiotelephone in the satellite footprint over the satellite radiotelephone frequency band as interference, along with the wireless communications that are received from the first radiotelephone in the satellite footprint over the satellite radiotelephone frequency band. An interference reducer is responsive to the space-based component and to the ancillary terrestrial network that is configured to reduce the interference from the wireless communications that are received by the space-based component from the first radiotelephone in the satellite footprint over the satellite radiotelephone frequency band, using the wireless communications that are received by the ancillary terrestrial network from the second radiotelephone in the satellite footprint over the satellite radiotelephone frequency band. U.S. Patent Application Publication No. 2003/0054761 A1, published Mar. 20, 2003 to coinventor Karabinis and entitled Spatial Guardbands for Terrestrial Reuse of Satellite Frequencies , the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein, describes satellite radiotelephone systems that include a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band. The satellite footprint is divided into a plurality of satellite cells, in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused. An ancillary terrestrial network is configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is used in a satellite cell in the satellite footprint, outside the cell and in some embodiments separated therefrom by a spatial guardband. The spatial guardband may be sufficiently large to reduce or prevent interference between the at least one of the satellite radiotelephone frequencies that is used in the satellite cell in the satellite footprint, and the at least one of the satellite radiotelephone frequencies that is terrestrially reused outside the satellite cell and separated therefrom by the spatial guardband. The spatial guardband may be about half a radius of a satellite cell in width. | <SOH> SUMMARY OF THE INVENTION <EOH>Some embodiments of the present invention allow two satellite and/or terrestrial communications systems to use the same frequency or frequencies for communications in geographically distinct, overlapping and/or congruent footprints while reducing interference in a given system (inter-system interference) that is caused by the same frequency signal(s) that is (are) used by the other system. In some embodiments, a satellite of a first satellite and/or terrestrial system includes a receive-only ancillary antenna that is configured to receive signals, occupying at least some of the frequencies of the first satellite and/or terrestrial system, from the second satellite and/or terrestrial system footprint. The received signal(s) from the ancillary antenna can be used to reduce interference to the first satellite and/or terrestrial system by the second satellite and/or terrestrial system. In other embodiments, at least some of the signals from the second satellite and/or terrestrial communications system that have occupied and/or are occupying at least some of the frequencies of the first satellite and/or terrestrial communications system are routed by a gateway and/or other component(s) of the first and/or second satellite and/or terrestrial system, before or after regeneration, to a gateway and/or other component(s) of the first satellite and/or terrestrial system. The routed signals may then be used to improve a signal-to-interference and/or -noise measure of a desired signal and for interference reduction of a desired signal. Finally, other embodiments need not use a separate ancillary (receive-only) antenna or inter-system routing to reduce interference. Rather, in a given satellite and/or terrestrial communications system, a desired signal plus interference received by a given satellite cell of a satellite over one or more frequencies, and received signals from at least one adjacent and/or non-adjacent satellite cells of the satellite, received over the one or more frequencies, are provided to a signal processor (interference reducer) that may include a plurality of transversal filters and a control mechanism that is used to adjust coefficients of the transversal filters. The signal processor (interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. Accordingly, these embodiments of the present invention allow two separate satellite and/or terrestrial communications systems to share at least some frequencies, while reducing or minimizing potential interference. Other embodiments of the present invention can use a signal processor (interference reducer), that may include a plurality of transversal filters and a control mechanism, to reduce interference within the satellite and/or terrestrial radiotelephone system (intra-system interference) that is caused by terrestrial reuse and/or intra-satellite system reuse of one or more frequencies that may also be used for space-based communications by a given satellite cell, and/or to improve a signal-to-interference and/or -noise measure of a desired signal of the given satellite cell. In some embodiments, the signals that are received at the satellite by a given satellite cell over a given frequency or frequencies, and the signals that are received at the satellite by adjacent and/or non-adjacent satellite cells over the given frequency or frequencies, are provided to a signal processor (interference reducer), to reduce and/or eliminate interference from one or more ancillary terrestrial components and/or intra-satellite frequency reuse that also use the given frequency or frequencies for terrestrial wireless and/or satellite communications. In other embodiments, signals at the given frequency or frequencies that are received from adjacent and/or non-adjacent satellite cells that do not reuse the given frequency or frequencies for satellite communications, also are provided to the signal processor (interference reducer) to reduce or eliminate interference by the terrestrial reuse of the frequency or frequencies by the same or another system and/or to improve a signal-to-interference and/or -noise measure of a desired signal. The signal processor (interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. Yet other embodiments of the present invention can combine the embodiments that were described above to provide both inter- and intra-system interference reduction, minimization and/or cancellation. Accordingly, inter- and/or intra-system interference from terrestrial- and/or space-based reuse of radiotelephone frequencies can be reduced, minimized or eliminated. In some embodiments of the present invention, methods of operating a satellite and/or terrestrial radiotelephone communications system are provided. A first radio signal is received via a first satellite reception path, for example, an antenna or spot beam, which serves a satellite cell. The received first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to the satellite cell. A second radio signal is received via a second satellite reception path, for example, via another antenna (ground- and/or space-based) or spot beam of the system and/or via a satellite and/or terrestrial infrastructure of another satellite and/or terrestrial communications system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed mathematically (software) and/or by an electronic circuit (hardware) to recover at least one measure of the desired satellite uplink signal. In further embodiments, the second satellite reception path may be configured to preferentially receive radio transmissions from an area outside of the satellite cell. For example, the area outside of the satellite cell may include another satellite cell that uses at least one of the frequencies assigned to and/or used by the satellite cell and/or a coverage area of another satellite and/or terrestrial communications system that uses at least one of the frequencies assigned to and/or used by the satellite cell. In some embodiments of the present invention, the first and second satellite reception paths may include respective first and second spot beams that serve respective first and second satellite cells of the satellite and/or terrestrial radiotelephone communications system. The second satellite cell may use a frequency or frequencies assigned to and/or used by the first satellite cell, may be adjacent a third satellite cell that uses a frequency or frequencies assigned to and/or used by the first satellite cell, may overlap or be adjacent a terrestrial cell and/or area that uses a frequency or frequencies assigned to and/or used by the first satellite cell and/or may overlap or be adjacent a coverage area of a second satellite and/or terrestrial radiotelephone communications system that uses a frequency or frequencies assigned to and/or used by the first satellite cell. According to some embodiments, the first satellite reception path includes a first satellite antenna positioned at a first satellite of the satellite and/or terrestrial radiotelephone communications system, and the second satellite reception path includes a second satellite antenna positioned at a second satellite of the satellite and/or terrestrial radiotelephone communications system. In other embodiments, the first satellite reception path may include a first satellite antenna positioned at a satellite of the satellite and/or terrestrial radiotelephone communications system, and the second satellite reception path may include a second and/or the first satellite antenna positioned at the same satellite. In yet further embodiments, the second satellite reception path may include a satellite of a second satellite and/or terrestrial radiotelephone communications system. The second satellite reception path may further include a terrestrial antenna configured to receive a feeder link transmission from the satellite of the second satellite and/or terrestrial radiotelephone communications system, and the second radio signal may be conveyed to the first and/or second satellite and/or terrestrial radiotelephone communications system via the terrestrial antenna. The terrestrial antenna may be coupled to a gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system, and the second radio signal may be conveyed to the first satellite and/or terrestrial radiotelephone communications system via the gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system. The terrestrial antenna may be coupled to a gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system, e.g., directly or through other elements of the first and/or second system, and the second radio signal may be conveyed from the terrestrial antenna to the gateway of the first and/or second satellite and/or terrestrial radiotelephone communications system. According to other aspects of the present invention, the first and second radio signals may be applied to a signal processor (interference reducer) comprising respective first and second transversal filters. Outputs of the first and second transversal filters may be combined, and at least one measure of the desired signal may be recovered from the combined outputs. The first and second transversal filters may be adjusted responsive to a measure of the combined outputs and/or a measure of the first and/or second radio signals. The signal processor (interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. According to other aspects of the present invention, first and second radio signals are received via respective first and second spot beams that serve respective first and second satellite cells of the satellite and/or terrestrial radiotelephone communications system. The first radio signal includes a desired satellite uplink signal transmitted from a first source in the first satellite cell using a frequency or frequencies assigned to the first satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to and/or used by the first satellite cell, and the second radio signal includes a measure of the interfering signal. The first and second radio signals are processed using, for example, an adaptive signal processor (adaptive interference reducer), to improve a signal-to-interference and/or -noise measure of the desired satellite uplink signal and recover the desired satellite uplink signal. The adaptive signal processor (adaptive interference reducer) may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. In additional embodiments of the present invention, a first radio signal is received via a first satellite reception path that serves a satellite cell of the first satellite and/or terrestrial radiotelephone communications system. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source communicating with the second satellite and/or terrestrial radiotelephone communications system using at least one frequency assigned to and/or used by the satellite cell. A second radio signal is received via a second satellite reception path configured to preferentially receive transmissions from a coverage area of the second satellite and/or terrestrial communications system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed to recover the desired satellite uplink signal. According to some embodiments of the present invention, methods of operating a first satellite and/or terrestrial radiotelephone communications system to reduce interference from a second satellite and/or terrestrial communications system are provided. A first radio signal is received via a first satellite configured to preferentially receive transmissions from a coverage area of the first satellite and/or terrestrial radiotelephone communications system. The first radio signal includes a desired satellite uplink signal transmitted from a first source in the coverage area of the first satellite and/or terrestrial radiotelephone communications system and an interfering signal transmitted from at least one second source communicating with the second satellite and/or terrestrial communications system using at least one frequency of the first signal. A second radio signal is received via a second satellite and/or terrestrial antenna configured to preferentially receive transmissions from a coverage area of the second satellite and/or terrestrial communications system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed to recover the desired satellite uplink signal. The second radio signal may be received from the second satellite via a terrestrial antenna configured to receive feeder link transmissions from the second satellite. In some system embodiments of the present invention, a system includes a first satellite reception path that serves a satellite cell and that receives a first radio signal. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to and/or used by the satellite cell. The system further includes a second satellite reception path that receives a second radio signal including a measure of the interfering signal. The system also includes an interference-suppressing signal processor that processes the first and second radio signals to recover at least one measure and/or at least one element of the desired satellite uplink signal. The interference-suppressing signal processor may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. In further embodiments of the present invention, an apparatus includes an interference-suppressing signal processor configured to receive a first radio signal from a first satellite reception path that serves a satellite cell. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to and/or used by the satellite cell. The interference-suppressing signal processor is further configured to receive a second radio signal from a second satellite reception path that receives a second radio signal including a measure of the interfering signal, and to process the first and second radio signals to recover at least one measure and/or at least one element of the desired satellite uplink signal. The interference-suppressing signal processor may include an adaptive interference reducer. The interference-suppressing signal processor may include first and second transversal filters that receive respective ones of the first and second radio signals, a combiner that combines outputs of the first and second transversal filters, and a detector that recovers at least one measure and/or element of the desired signal from the combined outputs. The interference-suppressing signal processor may further include a controller that adjusts the first and second transversal filters responsive to a measure of the combined outputs and/or a measure of the first and/or second radio signals. The interference suppressing signal processor and/or the interference reducer may be configured to use at least one transversal filter to form an output signal and/or may be configured to perform mathematical operations, such as a matrix inversion, vector-matrix multiplication, scalar multiplication, subtraction, and/or addition, on the first and/or second signals (and/or on at least one measure thereof) to form an output signal. According to additional embodiments of the present invention, a satellite and/or terrestrial radiotelephone communications system includes first and second spot beams that serve respective first and second satellite cells of the satellite and/or terrestrial radiotelephone communications system and that receive respective first and second radio signals. The first radio signal includes a desired satellite uplink signal transmitted from a first source in the first satellite cell using a frequency or frequencies assigned to the first satellite cell and an interfering signal transmitted from at least one second source using at least one frequency assigned to the first satellite cell. The second radio signal includes a measure of the interfering signal. The system further includes an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. In yet further embodiments of the present invention, a system includes a first satellite reception path that serves a satellite cell of a first satellite and/or terrestrial radiotelephone communications system and receives a first radio signal therefrom. The first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency or frequencies assigned to the satellite cell and an interfering signal transmitted from at least one second source communicating with a second satellite and/or terrestrial radiotelephone communications system using at least one frequency assigned to the satellite cell. The system also includes a second satellite reception path that preferentially receives transmissions from a coverage area of the second satellite and/or terrestrial communications system and that receives a second radio signal including a measure of the interfering signal. The system further includes an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. In additional embodiments, a system includes a first satellite configured to preferentially receive transmissions from a coverage area of a first satellite and/or terrestrial radiotelephone communications system and that receives a first radio signal including a desired satellite uplink signal transmitted from a first source in the coverage area of the first satellite and/or terrestrial radiotelephone communications system using a frequency or frequencies and an interfering signal transmitted from at least one second source communicating with a second satellite and/or terrestrial communications system using the frequency or at least one of the frequencies. The system also includes a terrestrial antenna configured to receive feeder link transmissions from a second satellite configured to preferentially receive transmissions from a coverage area of the second satellite and/or terrestrial communications system and that receives a second radio signal including a measure of the interfering signal. The system further includes an interference-suppressing signal processor that processes the first and second radio signals to recover the desired satellite uplink signal. | 20040714 | 20080304 | 20050217 | 62639.0 | 0 | PEREZ, ANGELICA | INTRA-AND/OR INTER-SYSTEM INTERFERENCE REDUCING SYSTEMS AND METHODS FOR SATELLITE COMMUNICATIONS SYSTEMS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,890,854 | ACCEPTED | Personalization of placed content ordering in search results | A system and method for using a user profile to order placed content in search results returned by a search engine. The user profile is based on search queries submitted by a user, the user's specific interaction with the documents identified by the search engine and personal information provided by the user. Placed content is ranked by a score based at least in part on a similarity of a particular placed content to the user's profile. User profiles can be created and/or stored on the client side or server side of a client-server network environment. | 1. A method of personalizing placed content, comprising: determining an interest of a user; accessing a user profile associated with the user; identifying a set of placed content that matches the interest of the user; and ordering the set of placed content in accordance with the user profile. 2. The method of claim 1, wherein the ordering includes assigning a score to each of the set of placed content in accordance with the user profile and a respective bid for the placed content. 3. The method of claim 1, wherein the ordering includes assigning a score to each of the set of placed content in accordance with the user profile and a respective click through rate for the placed content. 4. A method of personalizing placed content associated with a search query, comprising: receiving a search query from a user; accessing a user profile associated with the user; identifying a set of placed content that matches the search query; and ordering the set of placed content in accordance with the user profile. 5. The method of claim 4, wherein the ordering includes assigning a score to each of the set of placed content in accordance with the user profile and a respective bid for the placed content. 6. The method of claim 4, wherein the ordering includes assigning a score to each of the set of placed content in accordance with the user profile and a respective click through rate for the placed content. 7. A method of personalizing placed content associated with a search query, comprising: receiving a search query from a user; accessing a user profile associated with the user; identifying a set of placed content that matches the search query; assigning a score to each of the set of placed content in accordance with the user profile, a respective bid value for the placed content, and a respective click through rate for the placed content; and ranking the set of placed content according to their scores. 8. The method of claim 7, wherein the user profile is based, at least in part, on query terms in a plurality of previously submitted search queries. 9. The method of claim 7, wherein the user profile is based on information about the user, including information derived from a set of documents, the set of documents comprising a plurality of documents selected from the set consisting of documents identified by search results from a search engine, documents linked to the documents identified by search results from the search engine, documents linked to the documents accessed by the user, and documents browsed by the user. 10. The method of claim 7, wherein the assigning the score includes determining a similarity score between the user profile and a placed content profile associated with each placed content. 11. The method of claim 10, wherein the determining of the similarity score includes determining a mathematical distance between a user profile vector of the user profile, the user profile vector including first pairs of categories and respective weights, and a placed content profile vector of the placed content, the placed content profile vector including second pairs of categories and respective weights. 12. The method of claim 10, further including associating the similarity score with a scaling factor. 13. The method of claim 10, further including associating the similarity score with a scaling factor wherein the scaling factor is selected from one of a plurality of subfactors, each of the subfactors associated with a respective range of values of the similarity score. 14. The method of claim 12, wherein the assigning the score to each of the set of placed content includes multiplying the scaling factor, the respective click through rate and the respective bid value. 15. The method of claim 14, wherein the scaling factor associated with a maximum similarity score is less than the scaling factor associated with a mid-point similarity score. 16. The method of claim 12, wherein the scaling factor is determined in accordance with statistical information relating similarity scores to click through rates. 17. The method of claim 71, further including providing the placed content as an advertisement. 18. A system for personalizing placed content, comprising: a user profile; and a placed content server, including a plurality of placed content, for identifying a subset of the plurality of placed content that matches an identified user interest and that assigns a score to each placed content in the subset in accordance with the user profile, and that ranks the subset based on the respective scores of the placed content. 19. The system of claim 18, wherein the placed content server is configured to assign a score to each placed content in the subset in accordance with the user profile and a respective bid for the placed content. 20. The system of claim 18, wherein the placed content server is configured to assign a score to each placed content in the subset in accordance with the user profile and a respective click through rate for the placed content. 21. A system for personalizing placed content associated with a search query, comprising: a user profile; and a placed content server, including a plurality of placed content, for identifying a subset of the plurality of placed content that matches a search query and that assigns a score to each placed content in the subset in accordance with the user profile, and that ranks the subset based on the respective scores of the placed content. 22. The system of claim 21, wherein the placed content server is configured to assign a score to each placed content in the subset in accordance with the user profile and a respective bid for the placed content. 23. The system of claim 21, wherein the placed content server is configured to assign a score to each placed content in the subset in accordance with the user profile and a respective click through rate for the placed content. 24. A system for personalizing placed content associated with a search query, comprising: a user profile; and a placed content server, including a plurality of placed content, for identifying a subset of the plurality of placed content that matches a search query and that assigns a score to each placed content in the subset in accordance with the user profile, a respective bid value for the placed content, and a respective click through rate for the placed content, and that ranks the subset based on the respective scores of the placed content. 25. The system of claim 24, wherein the user profile is based, at least in part, on query terms in a plurality of previously submitted search queries. 26. The system of claim 24, wherein the user profile is based on information about the user, including information derived from a set of documents, the set of documents comprising a plurality of documents selected from the set consisting of documents identified by search results from a search engine, documents linked to the documents identified by search results from the search engine, documents linked to the documents accessed by the user, and documents browsed by the user. 27. The system of claim 24, wherein the score is based on a similarity score between the user profile and a placed content profile associated with each placed content. 28. The system of claim 27, wherein the similarity score is based on a mathematical distance between a user profile vector of the user profile, the user profile vector including first pairs of categories and respective weights, and a placed content profile vector of the placed content, the placed content profile vector including second pairs of categories and respective weights. 29. The system of claim 27, further including a scaling factor associated with the similarity score. 30. The system of claim 29, wherein the scaling factor is one a plurality of subfactors, each of the subfactors associated with a respective range of values of the similarity score. 31. The system of claim 29, wherein the score of each placed content in the set of placed content corresponds to the multiplicative product of the respective scaling factor, the respective click through rate and the respective bid value for the placed content. 32. The system of claim 31, wherein the scaling factor associated with a maximum similarity score is less than the scaling factor associated with a mid-point similarity score. 33. The system of claim 29, wherein the scaling factor is based on statistical information relating similarity scores to click through rates. 34. The system of claim 24, wherein the placed content is an advertisement. 35. A computer program product, for use in conjunction with a computer system, the computer program product comprising: instructions for identifying an interest of a user; instructions for accessing a user profile associated with the user; instructions for identifying a set of placed content that matches the identified user interest; instructions for ordering the set of placed content in accordance with the user profile. 36. The computer program product of claim 35, wherein the instructions for ordering include instructions for assigning a score to each of the set of placed content in accordance with the user profile and a respective bid for the placed content. 37. The computer program product of claim 35, the instructions for ordering include instructions for assigning a score to each of the set of placed content in accordance with the user profile and a respective click through rate for the placed content. 38. A computer program product, for use in conjunction with a computer system, the computer program product comprising: instructions for receiving a search query from a user; instructions for accessing a user profile associated with the user; instructions for identifying a set of placed content that matches the search query; instructions for assigning a score to each of the set of placed content in accordance with the user profile; and instructions for ranking the set of placed content according to their scores. 39. The computer program product of claim 38, wherein the instructions for ranking include instructions for assigning a score to each of the set of placed content in accordance with the user profile and a respective bid for the placed content. 40. The computer program product of claim 38, wherein the instructions for ranking include instructions for assigning a score to each of the set of placed content in accordance with the user profile and a respective click through rate for the placed content. 41. A computer program product, for use in conjunction with a computer system, the computer program product comprising: instructions for receiving a search query from a user; instructions for accessing a user profile associated with the user; instructions for identifying a set of placed content that matches the search query; instructions for assigning a score to each of the set of placed content in accordance with the user profile, a respective bid value for the placed content, and a respective click through rate for the placed content; and instructions for ranking the set of placed content according to their scores. 42. The computer program product of claim 41, wherein the user profile is based, at least in part, on query terms in a plurality of previously submitted search queries. 43. The computer program product of claim 41, wherein the user profile is based on information about the user, including information derived from a set of documents, the set of documents comprising a plurality of documents selected from the set consisting of documents identified by search results from a search engine, documents linked to the documents identified by search results from the search engine, documents linked to the documents accessed by the user, and documents browsed by the user. 44. The computer program product of claim 41, wherein the instructions for assigning the score include determining a similarity score between the user profile and a placed content profile associated with each placed content. 45. The computer program product of claim 44, wherein the instructions for determining the similarity score include determining a mathematical distance between a user profile vector of the user profile, the user profile vector including first pairs of categories and respective weights, and a placed content profile vector of the placed content, the placed content profile vector including second pairs of categories and respective weights. 46. The computer program product of claim 44, further including instructions for associating the similarity score with a scaling factor. 47. The computer program product of claim 45, further including instructions for associating the similarity score with a scaling factor wherein the scaling factor is selected from one of a plurality of subfactors, each of the subfactors associated with a respective range of normalized values of the mathematical distance. 48. The computer program product of claim 46, wherein the instructions for assigning the score to each of the set of placed content includes instructions for multiplying the scaling factor, the respective click through rate and the respective bid value. 49. The computer program product of claim 48, wherein the scaling factor associated with a maximum similarity score is less than the scaling factor associated with a mid-point similarity score. 50. The computer program product of claim 46, wherein the scaling factor is determined in accordance with statistical information relating similarity scores to click through rates. 51. The computer program product of claim 41, wherein the placed content is an advertisement. 52. A system for personalizing placed content associated with a search query, comprising: means for receiving a search query from a user; means for accessing a user profile for the user; means for identifying a set of placed content that matches the search query; means for assigning a score to each of the set of placed content in accordance with the user profile; and means for ranking the set of placed content according to their scores. | RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 10/676,711, filed Sep. 30, 2003, which application is incorporated by reference herein in its entirety. FIELD OF THE INVENTION The present invention relates generally to the field of a search engine in a computer network system, in particular to system and method of creating and using a user profile to customize ordering of placed content in response to search queries submitted by the user. BACKGROUND OF THE INVENTION Search engines provide a powerful source of indexed documents from the Internet (or an intranet) that can be rapidly scanned in response to a search query submitted by a user. Such a query is usually very short (on average about two to three words). As the number of documents accessible via the Internet grows, the number of documents that match the query may also increase. However, not every document matching the query is equally important from the user's perspective. As a result, a user is easily overwhelmed by an enormous number of documents returned by a search engine, if the engine does not order the search results based on their relevance to the user's query. One approach to improving the relevance of search results to a search query is to use the link structure of different web pages to compute global “importance” scores that can be used to influence the ranking of search results. This is sometimes referred to as the PageRank algorithm. A more detailed description of the PageRank algorithm can be found in the article “The Anatomy of a Large-Scale Hypertextual Search Engine” by S. Brin and L. Page, 7th International World Wide Web Conference, Brisbane, Australia and U.S. Pat. No. 6,285,999, both of which are hereby incorporated by reference as background information. An important assumption in the PageRank algorithm is that there is a “random surfer” who starts his web surfing journey at a randomly picked web page and keeps clicking on the links embedded in the web pages, never hitting the “back” button. Eventually, when this random surfer gets bored of the journey, he may re-start a new journey by randomly picking another web page. The probability that the random surfer visits (i.e., views or downloads) a web page depends on the web page's page rank. From an end user's perspective, a search engine using the PageRank algorithm treats a search query the same way no matter who submits the query, because the search engine does not ask the user to provide any information that can uniquely identify the user. The only factor that affects the search results is the search query itself, e.g., how many terms are in the query and in what order. The search results are a best fit for the interest of an abstract user, the “random surfer”, and they are not be adjusted to fit a specific user's preferences or interests. In reality, a user like the random surfer never exists. Every user has his own preferences when he submits a query to a search engine. The quality of the search results returned by the engine has to be evaluated by its users' satisfaction. When a user's preferences can be well defined by the query itself, or when the user's preference is similar to the random surfer's preference with respect to a specific query, the user is more likely to be satisfied with the search results. However, if the user's preference is significantly biased by some personal factors that are not clearly reflected in a search query itself, or if the user's preference is quite different from the random user's preference, the search results from the same search engine may be less useful to the user, if not useless. As suggested above, the journey of the random surfer tends to be random and neutral, without any obvious inclination towards a particular direction. When a search engine returns only a handful of search results that match a query, the order of the returned results is less significant because the requesting user may be able to afford the time to browse each of them to discover the items most relevant to himself. However, with billions of web pages connected to the Internet, a search engine often returns hundreds or even thousands of documents that match a search query. In this case, the ordering of the search results is very important. A user who has a preference different from that of the random surfer may not find what he is looking for in the first five to ten documents listed in the search results. When that happens, the user is usually left with two options: (1) either spending the time required to review more of the listed documents so as to locate the relevant documents; or (2) refining the search query so as to reduce the number of documents that match the query. Query refinement is often a non-trivial task, sometimes requiring more knowledge of the subject or more expertise with search engines than the user possesses, and sometimes requiring more time and effort than the user is willing to expend. For example, assume that a user submits to a search engine a search query having only one term “blackberry”. Without any other context, on the top of a list of documents returned by a PageRank-based search engine may be a link to www.blackberry.net, because this web page has the highest page rank. However, if the query requester is a person with interests in foods and cooking, it would be more useful to order the search results so as to include at the top of the returned results web pages with recipes or other food related text, pictures or the like. It would be desirable to have a search engine that is able to reorder its search results, or to otherwise customize the search results, so as to emphasize web pages that are most likely to be of interest to the person submitting the search query. Further, it would be desirable for such a system to require minimal input from individual users, operating largely or completely without explicit input from the user with regard to the user's preferences and interests. Finally, it would be desirable for such a system to meet users' requirements with respect to security and privacy. SUMMARY In a method of personalizing placed content, an interest of a user is determined, and a user profile associated with the user is accessed. A set of placed content that matches the interest of the user is identified, and the set of placed content is ordered in accordance with the user profile. In one aspect of the invention, a search engine utilizes user profiles to customize search results, which may include placed content as well as other or general content. A user profile comprises multiple items that characterize a user's interests or preferences. These items are extracted from various information sources, including previous search queries submitted by the user, links from or to the documents identified by the previous queries, sampled content from the identified documents as well as personal information implicitly or explicitly provided by the user. When the search engine receives a search query from a user, it identifies a set of placed content that matches the search query. Each placed content is associated with a rank based at least in part a similarity of the placed content to the user profile. The placed content items are then ordered according to their ranks. The present invention, including user profile construction and search results re-ordering and/or scoring, can be implemented on either the client side or the server side of a client-server network environment. BRIEF DESCRIPTION OF THE DRAWINGS The aforementioned features and advantages of the invention as well as additional features and advantages thereof will be more clearly understood hereinafter as a result of a detailed description of preferred embodiments of the invention when taken in conjunction with the drawings. FIG. 1 illustrates a client-server network environment. FIG. 2 illustrates multiple sources of user information and their relationship to a user profile. FIG. 3 is an exemplary data structure that may be used for storing term-based profiles for a plurality of users. FIG. 4A is an exemplary category map that may be used for classifying a user's past search experience. FIG. 4B is an exemplary data structure that may be used for storing category-based profiles for a plurality of users. FIG. 5 is an exemplary data structure that may be used for storing link-based profiles for a plurality of users. FIG. 6 is a flowchart illustrating paragraph sampling. FIG. 7A is a flowchart illustrating context analysis. FIG. 7B depicts a process of identifying important terms using context analysis. FIG. 8 illustrates a plurality of exemplary data structures that may be used for storing information about documents after term-based, category-based and/or link-based analyses, respectively. FIG. 9A is a flowchart illustrating a personalized web search process according to one embodiment. FIG. 9B is a flowchart illustrating a personalized web search process according to another embodiment. FIG. 10 is a block diagram of a personalized search engine. FIG. 11 is a flowchart illustrating a personalized placed content process according to an embodiment of the invention. Like reference numerals refer to corresponding parts throughout the several views of the drawings. DESCRIPTION OF EMBODIMENTS The embodiments discussed below include systems and methods that create a user profile based a user's past experience with a search engine and then use the user profile to rank search results in response to search queries provided by the user. FIG. 1 provides an overview of a typical client-server network environment 100 in which the present invention may be implemented. A plurality of clients 102 are connected to a search engine system 107 through a network 105, e.g., the Internet. Search engine system 107 comprises one or more search engines 104. A search engine 104 is responsible for processing a search query submitted by a client 102, generating search results in accordance with the search query and returning the results to the client. Search engine system 107 may also comprise one or more content servers 106, one or more user profile servers 108, and one or more placed content servers 111. A content server 106 stores a large number of indexed documents retrieved from different websites. Alternately, or in addition, the content server 106 stores an index of documents stored on various websites. In one embodiment, each indexed document is assigned a page rank according to the document's link structure. The page rank serves as a query independent measure of the document's importance. A search engine 104 communicates with one or more content servers 106 to select a plurality of documents in response to a specific search query. The search engine assigns a score to each document based on the document's page rank, the text associated with the document, and the search query. A search engine 104 may communicate with one or more placed content servers 111 to provide advertisements, or other types of placed content, in conjunction with the search results. Placed content servers 111 may communicate with the one or more user profile servers 108. Placed content is described more fully below. A user profile server 108 stores a plurality of user profiles. Each profile includes information that uniquely identifies a user as well as his previous search experience and personal information, which can be used to refine search results in response to the search queries submitted by this user. Different approaches are available for user profile construction. For example, a user profile can be created by requiring a first-time user to fill in a form or answer a survey. This approach may be useful in certain applications such as opening a bank account. But it is hardly a favorable one in the context of a search engine. First, a user's interaction with a search engine is usually a dynamic process. As time goes on, the user's interests may change. This change may be reflected by the search queries submitted by the user, or by the user's handling of the search results, or both. The user's answers to questions on a form tend to become less useful over time, unless the user chooses to update his answers periodically. Unlike an occasional update of phone number in the case of an on-line bank account, frequent updates of a user profile in the case of a search engine significantly affect its user friendliness, which is an important consideration when a user chooses among the search engines currently available. Further, it is known that users are reluctant to provide explicit feedback, such as filling out of a form, as many users find it too burdensome. Thus, while some users may provide explicit feedback on their interests, it is desirable to have a procedure for implicitly obtaining information about the user's interests without requiring any explicit or new actions by the user. It is has been observed that a search engine user's past search activities provide useful hints about the user's personal search preferences. FIG. 2 provides a list of sources of user information that are beneficial for user profile construction. For example, previously submitted search queries 201 are very helpful in profiling a user's interests. If a user has submitted multiple search queries related to diabetes, it is more likely than not that this is a topic of interest to the user. If the user subsequently submits a query including the term “organic food”, it can be reasonably inferred that he may be more interested in those organic foods that are helpful in fighting diabetes. Similarly, the universal resource locators (URL) 203 associated with the search results in response to the previous search queries and their corresponding anchor texts 205, especially for search result items that have been selected or “visited” by the user (e.g., downloaded or otherwise viewed by the user), are helpful in determining the user's preferences. When a first page contains a link to a second page, and the link has text associated with it (e.g., text neighboring the link), the text associated with the link is called “anchor text” with respect to the second page. Anchor text establishes a relationship between the text associated with a URL link in a document and another document to which the URL link points. The advantages of anchor text include that it often provides an accurate description of the document to which the URL link points, and it can be used to index documents that cannot be indexed by a text-based search engine, such as images or databases. After receiving search results, the user may click on some of the URL links, thereby downloading the documents referenced by those links, so as to learn more details about those documents. Certain types of general information 207 can be associated with a set of user selected or use identified documents. For purposes of forming a user profile, the identified documents from which information is derived for inclusion in the user profile may include: documents identified by search results from the search engine, documents accessed (e.g., viewed or downloaded, for example using a browser application) by the user (including documents not identified in prior search results), documents linked to the documents identified by search results from the search engine, and documents linked to the documents accessed by the user, or any subset of such documents. The general information 207 about the identified documents may answer questions such as, what is the format of the document? Is it in hypertext markup language (HTML), plain text, portable document format (PDF), or Microsoft Word? What is the topic of the document? Is it about science, health or business? This information is also helpful in profiling the user's interests. In addition, information about a user's activities 209 with respect to the user selected documents (sometimes herein call the identified documents), such as how long the user spent viewing the document, the amount of scrolling activity on the document, and whether the user has printed, saved or bookmarked the document, also suggests the importance of the document to the user as well as the user's preferences. In some embodiments, information about user activities 209 is used both when weighting the importance of information extracted or derived from the user identified documents. In some embodiments, information about user activities 209 is used to determine which of the user identified documents to use as the basis for deriving the user profile. For example, information 209 may be used to select only documents that received significant user activity (in accordance with predefined criteria) for generating the user profile, or information 209 may be used to exclude from the profiling process documents that the user viewed for less than a predefined threshold amount of time. The content of the identified documents from previous search activities is a rich source of information about a user's interests and preferences. Key terms appearing in the identified documents and their frequencies with which they appear in the identified documents are not only useful for indexing the document, but are also a strong indication of the user's personal interests, especially when they are combined with other types of user information discussed above. In one embodiment, instead of the whole documents, sampled content 211 from the identified documents is extracted for the purpose of user profile construction, to save storage space and computational cost. In another embodiment, various information related to the identified documents may be classified to constitute category information 213 about the identified documents. The various information could include the types of individuals who have visited the page previously or other meta-data which could describe the document. More discussion about content sampling, the process of identifying key terms in an identified document and the usage of the category information is provided below. Another potential source of information for a user profile is the user's browsing patterns 217. The user's browsing patterns may be represented by the URLs visited by the user over a period of time, such as the preceding N days (e.g., 60 days). In some embodiments, user profile information is weighted in accordance with its age, with more recent information being given larger weight and less recent information being given smaller weight. This helps the user profile to better track changes in the user's interests, and to reduce the impact of passing interests or subjects of dwindling interest to the user. A variety of data structures can be used to support a time weighted user profile, typically including a number of bins or tiers for holding user information associated with a sequence of time periods. Optionally, a user may choose to offer personal information 215, including demographic and geographic information associated with the user, such as the user's age or age range, educational level or range, income level or range, language preferences, marital status, geographic location (e.g., the city, state and country in which the user resides, and possibly also including additional information such as street address, zip code, and telephone area code), cultural background or preferences, or any subset of these. Compared with other types of personal information such as a user's favorite sports or movies that are often time varying, this personal information is more static and more difficult to infer from the user's search queries and search results, but may be crucial in correctly interpreting certain queries submitted by the user. For example, if a user submits a query containing “Japanese restaurant”, it is very likely that he may be searching for a local Japanese restaurant for dinner. Without knowing the user's geographical location, it is hard to order the search results so as to bring to the top those items that are most relevant to the user's true intention. In certain cases, however, it is possible to infer this information. For example, users often select results associated with a specific region corresponding to where they live. Creating a user profile 230 from the various sources of user information is a dynamic and complex process. In some embodiments, the process is divided into sub-processes. Each sub-process produces one type of user profile characterizing a user's interests or preferences from a particular perspective. They are: a term-based profile 231—this profile represents a user's search preferences with a plurality of terms, where each term is given a weight indicating the importance of the term to the user; a category-based profile 233—this profile correlates a user's search preferences with a set of categories, which may be organized in a hierarchal fashion, with each category being given a weight indicating the extent of correlation between the user's search preferences and the category; and a link-based profile 235—this profile identifies a plurality of links that are directly or indirectly related to the user's search preferences, with each link being given a weight indicating the relevance between the user's search preferences and the link. In some embodiments, the user profile 230 includes only a subset of these profiles 231, 233, 235, for example just one or two of these profiles. In one embodiment, the user profile 230 includes a term-based profile 231 and a category-based profile 233, but not a link-based profile 235. A category-based profile 233 may be constructed, for instance, by mapping sets of search terms (e.g., from each individual query) or identified content terms (from a particular identified document) to categories, and then aggregating the resulting sets of categories, weighting the categories both in terms of their frequency of occurrence and the relevance of the search terms or identified content terms to the categories. Alternately, all the search terms or identified content terms accumulated over a period of time may be treated as a group, for mapping into weighted categories. Furthermore, user provided personal information 215 may be mapped into weighted categories and those categories may be combined or aggregated with the weighted categories generated using any of the techniques discussed above. Other suitable ways of mapping user related information into categories may also be used. In some embodiments, the user profile 230 is an aggregated profile based on information associated with multiple users. The users whose profile information is aggregated may be selected or identified in a number of ways. For instance, all the users who are members of a club or other organization, or employees of a particular company, may have their profile information aggregated. In another example, users having similar pre-aggregation user profiles may have their profile information aggregated. Alternately, an organization or web site may have a “user profile” associated with it, which may be automatically generated based on activities of the organization's members or which may be customized by or for the organization. A search engine or other service may utilize the organization's user profile when executing a search query or when providing placed content or other content in conjunction with any other suitable information service to help select content that is of interest to the requester or subscriber. In one embodiment, a user profile is created and stored on a server (e.g., user profile server 108) associated with a search engine. The advantage of such deployment is that the user profile can be easily accessed by multiple computers, and that since the profile is stored on a server associated with (or part of) the search engine 104, it can be easily used by the search engine 104 to personalize the search results. In another embodiment, the user profile can be created and stored on the user's computer, sometimes called the client in a network environment. Creating and storing a user profile on a user's computer (e.g., in a cookie) not only reduces the computational and storage cost for the search engine's servers, but also satisfies some users' privacy requirements. In yet another embodiment, the user profile may be created and updated on the client, but stored on a server. Such embodiment combines some of the benefits illustrated in the other two embodiments. A disadvantage of this arrangement is that it may increase the network traffic between clients and the servers. It is understood by a person of ordinary skill in the art that the user profiles of the present invention can be implemented using client computers, server computers, or both. FIG. 3 illustrates an exemplary data structure, a term-based profile table 300, that may be used for storing term-based profiles for a plurality of users. Table 300 includes a plurality of records 310, each record corresponding to a user's term-based profile. A term-based profile record 310 includes a plurality of columns including a USER_ID column 320 and multiple columns of (TERM, WEIGHT) pairs 340. The USER_ID column stores a value that uniquely identifies a user or a group of users sharing the same set of (TERM, WEIGHT) pairs, and each (TERM, WEIGHT) pair 340 includes a term, typically 1-3 words long, that is usually important to the user or the group of users and a weight associated with the term that quantifies the importance of the term. In one embodiment, the term may be represented as one or more n-grams. An n-gram is defined as a sequence of n tokens, where the tokens may be words. For example, the phrase “search engine” is an n-gram of length 2, and the word “search” is an n-gram of length 1. N-grams can be used to represent textual objects as vectors. This makes it possible to apply geometric, statistical and other mathematical techniques, which are well defined for vectors, but not for objects in general. In the present invention, n-grams can be used to define a similarity measure between two terms based on the application of a mathematical function to the vector representations of the terms. The weight of a term is not necessarily a positive value. If a term has a negative weight, it may suggest that the user prefers that his search results should not include this term and the magnitude of the negative weight indicates the strength of the user's preference for avoiding this term in the search results. By way of example, for a group of surfing fans at Santa Cruz, Calif., the term-based profile may include terms like “surfing club”, “surfing event” and “Santa Cruz” with positive weights. The terms like “Internet surfing” or “web surfing” may also be included in the profile. However, these terms are more likely to receive a negative weight since they are irrelevant and confusing with the authentic preference of the users sharing this term-based profile. A term-based profile itemizes a user's preference using specific terms, each term having certain weight. If a document matches a term in a user's term-based profile, i.e., its content includes exactly this term, the term's weight will be assigned to the document; however, if a document does not match a term exactly, it will not receive any weight associated with this term. Such a requirement of relevance between a document and a user profile sometimes may be less flexible when dealing with various scenarios in which a fuzzy relevance between a user's preference and a document exists. For example, if a user's term-based profile includes terms like “Mozilla” and “browser”, a document containing no such terms, but other terms like “Galeon” or “Opera” will not receive any weight because they do not match any existing term in the profile, even though they are actually Internet browsers. To address the need for matching a user's interests without exact term matching, a user's profile may include a category-based profile. FIG. 4A illustrates a hierarchal category map 400 according to the Open Directory Project (http://dmoz.org/). Starting from the root level of map 400, documents are organized under several major topics, such as “Art”, “News”, “Sports”, etc. These major topics are often too broad to delineate a user's specific interest. Therefore, they are further divided into sub-topics that are more specific. For example, topic “Art” may comprise sub-topics like “Movie”, “Music” and “Literature” and the sub-topic “Music” may further comprise sub-sub-topics like “Lyrics”, “News” and “Reviews”. Note that each topic is associated with a unique CATEGORY_ID like 1.1 for “Art”, 1.4.2.3 for “Talk Show” and 1.6.1 for “Basketball”. Although FIG. 4A illustrates exemplary categories using the Open Directory Project, other types of categories could also be used. For example, categories could be determined by analyzing the various contents of documents or other information to produce categories of relevant information organized around concepts. In other terms, words or phrases can be mapped to clusters that relate to various concepts. One of ordinary skill in the art would recognize many different ways to categorize information into clusters that could aid in determining a document's relation to different concepts. A user's specific interests may be associated with multiple categories at various levels, each of which may have a weight indicating the degree of relevance between the category and the user's interest. The categories and weights could be determined by analyzing any or all of the information previously discussed relating to the user. In some embodiments, the categories are determined by analyzing any one or more of the following sets of information: previous search queries submitted by the user 201, URLs identified by the previous search queries 203, general information 207 about the identified documents 207 (e.g., meta-data embedded in or otherwise associated with the identified documents), the user's activities with respect to the identified documents 209 (e.g., user clicks on general content and/or placed content), sampled content from the identified documents 211, category information about the identified documents 213, the user's personal information 215, or any combination thereof. In one embodiment, a category-based profile may be implemented using a Hash table data structure as shown in FIG. 4B. A category-based profile table 450 includes a table 455 that comprises a plurality of records 460, each record including a USER_ID and a pointer pointing to another data structure, such as table 460-1. Table 460-1 may include two columns, CATEGORY_ID column 470 and WEIGHT column 480. CATEGORY_ID column 470 contains a category's identification number as shown in FIG. 4A, suggesting that this category is relevant to the user's interests and the value in the WEIGHT column 480 indicates the degree of relevance of the category to the user's interests. A user profile based upon the category map 400 is a topic-oriented implementation. The items in a category-based profile can also be organized in other ways. In one embodiment, a user's preference can be categorized based on the formats of the documents identified by the user, such as HTML, plain text, PDF, Microsoft Word, etc. Different formats may have different weights. In another embodiment, a user's preference can be categorized according to the types of the identified documents, e.g., an organization's homepage, a person's homepage, a research paper, or a news group posting, each type having an associated weight. Another type category that can be used to characterize a user's search preferences is document origin, for instance the country associated with each document's host. In yet another embodiment, the above-identified category-based profiles may co-exist, with each one reflecting one aspect of a user's preferences. Besides term-based and category-based profiles, another type of user profile is referred to as a link-based profile. As discussed above, the PageRank algorithm is based on the link structure that connects various documents over the Internet. A document that has more links pointing to it is often assigned a higher page rank and therefore attracts more attention from a search engine. Link information related to a document identified by a user can also be used to infer the user's preferences. In one embodiment, a list of preferred URLs are identified for a user by analyzing the frequency of his access to those URLs. Each preferred URL may be further weighted according to the time spent by the user and the user's scrolling activity at the URL, and/or other user activities (209, FIG. 2) when visiting the document at the URL. In another embodiment, a list of preferred hosts are identified for a user by analyzing the user's frequency of accessing web pages of different hosts. When two preferred URLs are related to the same host the weights of the two URLs may be combined to determine a weight for the host. In another embodiment, a list of preferred domains are identified for a user by analyzing the user's frequency of accessing web pages of different domains. For example, for finance.yahoo.com, the host is “finance.yahoo.com” while the domain is “yahoo.com”. FIG. 5 illustrates a link-based profile using a Hash table data structure. A link-based profile table 500 includes a table 510 that includes a plurality of records 520, each record including a USER_ID and a pointer pointing to another data structure, such as table 510-1. Table 510-1 may include two columns, LINK_ID column 530 and WEIGHT column 540. The identification number stored in the LINK_ID column 530 may be associated with a preferred URL or host. The actual URL/host/domain may be stored in the table instead of the LINK_ID, however it is preferable to store the LINK_ID to save storage space. A preferred list of URLs and/or hosts includes URLs and/or hosts that have been directly identified by the user. The preferred list of URLs and/or host may furthermore extend to URLs and/or hosts indirectly identified by using methods such as collaborative filtering or bibliometric analysis, which are known to persons of ordinary skill in the art. In one embodiment, the indirectly identified URLs and/or host include URLs or hosts that have links to/from the directly identified URLs and/or hosts. These indirectly identified URLs and/or hosts are weighted by the distance between them and the associated URLs or hosts that are directly identified by the user. For example, when a directly identified URL or host has a weight of 1, URLs or hosts that are one link away may have a weight of 0.5, URLs or hosts that are two links away may have a weight of 0.25, etc. This procedure can be further refined by reducing the weight of links that are not related to the topic of the original URL or host, e.g., links to copyright pages or web browser software that can be used to view the documents associated with the user selected URL or host. Irrelevant Links can be identified based on their context or their distribution. For example, copyright links often use specific terms (e.g., copyright or “All rights reserved” are commonly used terms in the anchor text of a copyright link); and links to a website from many unrelated websites may suggest that this website is not topically related (e.g., links to the Internet Explorer website are often included in unrelated websites). The indirect links can also be classified according to a set of topics and links with very different topics may be excluded or be assigned a low weight. The three types of user profiles discussed above are generally complimentary to one another since different profiles delineate a user's interests and preferences from different vantage points. However, this does not mean that one type of user profile, e.g., category-based profile, is incapable of playing a role that is typically played by another type of user profile. By way of example, a preferred URL or host in a link-based profile is often associated with a specific topic, e.g., finance.yahoo.com is a URL focusing on financial news. Therefore, what is achieved by a link-based profile that comprises a list of preferred URLs or hosts to characterize a user's preference may also be achievable, at least in part, by a category-based profile that has a set of categories that cover the same topics covered by preferred URLs or hosts. It is a non-trivial operation to construct various types of user profiles that can be stored in the data structures shown in FIGS. 3-5 based on the user information listed in FIG. 2. Given a document identified (e.g., viewed) by a user, different terms in the document may have different importance in revealing the topic of the document. Some terms, e.g., the document's title, may be extremely important, while other terms may have little importance. For example, many documents contain navigational links, copyright statements, disclaimers and other text that may not be related to the topic of the document. How to efficiently select appropriate documents, content from those documents and terms from within the content is a challenging topic in computational linguistics. Additionally, it is preferred to minimize the volume of user information processed, so as to make the process of user profile construction computationally efficient. Skipping less important terms in a document helps in accurately matching a document with a user's interest. Paragraph sampling (described below with reference to FIG. 6) is a procedure for automatically extracting content from a document that may be relevant to a user. An important observation behind this procedure is that less relevant content in a document, such as navigational links, copyright statements, disclaimer, etc., tend to be relatively short segments of text. In one embodiment, paragraph sampling looks for the paragraphs of greatest length in a document, processing the paragraphs in order of decreasing length until the length of a paragraph is below a predefined threshold. The paragraph sampling procedure optionally selects up to a certain maximum amount of content from each processed paragraph. If few paragraphs of suitable length are found in a document, the procedure falls back to extracting text from other parts of the document, such as anchor text and ALT tags. FIG. 6 is a flowchart illustrating the major steps of paragraph sampling. Paragraph sampling begins with the step 610 of removing predefined items, such as comments, JavaScript and style sheets, etc., from a document. These items are removed because they are usually related to visual aspects of the document when rendered on a browser and are unlikely to be relevant to the document's topic. Following that, the procedure may select the first N words (or M sentences) at step 620 from each paragraph whose length is greater than a threshold value, MinParagraphLength, as sampled content. In one embodiment, the values of N and M are chosen to be 100 and 5, respectively. Other values may be used in other embodiments. In order to reduce the computational and storage load associated with the paragraph sampling procedure, the procedure may impose a maximum limit, e.g., 1000 words, on the sampled content from each document. In one embodiment, the paragraph sampling procedure first organizes all the paragraphs in a document in length decreasing order, and then starts the sampling process with a paragraph of maximum length. It is noted that the beginning and end of a paragraph depend on the appearance of the paragraph in a browser, not on the presence of uninterrupted a text string in the HTML representation of the paragraph. For this reason, certain HTML commands, such as commands for inline links and for bold text, are ignored when determining paragraph boundaries. In some embodiments, the paragraph sampling procedure screens the first N words (or M sentences) so as to filter out those sentences including boilerplate terms like “Terms of Service” or “Best viewed”, because such sentences are usually deemed irrelevant to the document's topic. Before sampling a paragraph whose length is above the threshold value, the procedure may stop sampling content from the document if the number of words in the sampled content has reached the maximum word limit. If the maximum word limit has not been reached after processing all paragraphs of length greater than the threshold, optional steps 630, 640, 650 and 670 are performed. In particular, the procedure adds the document title (630), the non-inline HREF links (640), the ALT tags (650) and the meta tags (670) to the sampled content until it reaches the maximum word limit. Once the documents identified by a user have been scanned, the sampled content can be used for identifying a list of most important (or unimportant) terms through context analysis. Context analysis attempts to learn context terms that predict the most important (or unimportant) terms in a set of identified documents. Specifically, it looks for prefix patterns, postfix patterns, and a combination of both. For example, an expression “x's home page” may identify the term “x” as an important term for a user and therefore the postfix pattern “* home page” can be used to predict the location of an important term in a document, where the asterisk “*” represents any term that fits this postfix pattern. In general, the patterns identified by context analysis usually consist of m terms before an important (or unimportant) term and n terms after the important (or unimportant) term, where both m and n are greater than or equal to 0 and at least one of them is greater than 0. Typically, m and n are less than 5, and when non-zero are preferably between 1 and 3. Depending on its appearance frequency, a pattern may have an associated weight that indicates how important (or unimportant) the term recognized by the pattern is expected to be. According to one embodiment of the present invention (FIG. 7A), context analysis has two distinct phases, a training phase 701 and an operational phase 703. The training phase 701 receives and utilizes a list of predefined important terms 712, an optional list of predefined unimportant terms 714, and a set of training documents (step 710). In some embodiments, the list of predefined unimportant terms is not used. The source of the lists 712, 714 is not critical. In some embodiments, these lists 712, 714 are generated by extracting words or terms from a set of documents (e.g., a set of several thousand web pages of high page rank) in accordance with a set of rules, and then editing them to remove terms that in the opinion of the editor do not belong in the lists. The source of the training documents is also not critical. In some embodiments, the training documents comprise a randomly or pseudo-randomly selected set of documents already known to the search engine. In other embodiments, the training documents are selected from a database of documents in the search engine in accordance with predefined criteria. During the training phase 701, the training documents are processed (step 720), using the lists of predefined important and unimportant terms, so as to identify a plurality of context patterns (e.g., prefix patterns, postfix patterns, and prefix-postfix patterns) and to associate a weight with each identified context pattern. During the operational phase 703, the context patterns are applied to documents identified by the user (step 730) to identify a set of important terms (step 740) that characterize the user's specific interests and preferences. Learning and delineating a user's interests and preferences is usually an ongoing process. Therefore, the operational phase 703 may be repeated to update the set of important terms that have been captured previously. This may be done each time a user accesses a document, according to a predetermined schedule, at times determined in accordance with specified criteria, or otherwise from time to time. Similarly, the training phase 701 may also be repeated to discover new sets of context patterns and to recalibrate the weights associated with the identified context patterns. Below is a segment of pseudo code that exemplifies the training phase: For each document in the set { For each important term in the document { For m = 0 to MaxPrefix { For n = 0 to MaxPostfix { Extract the m words before the important term and the n words after the important term as s; Add 1 to ImportantContext(m,n,s); } } } For each unimportant term in the document { For m = 0 to MaxPrefix { For n = 0 to MaxPostfix { Extract the m words before the unimportant term and the n words after the unimportant term as s; Add 1 to UnimportantContext(m,n,s); } } } } For m = 0 to MaxPrefix { For n = 0 to MaxPostfix { For each value of s { Set the weight for s to a function of ImportantContext(m,n,s), and UnimportantContext(m,n,s); } } } In the pseudo code above, the expressions refers to a prefix pattern (n=0), a postfix pattern (m=0) or a combination of both (m>0 & n>0). Each occurrence of a specific pattern is registered at one of the two multi-dimensional arrays, ImportantContext(m, n, s) or UnimportantContext(m, n, s). The weight of a prefix, postfix or combination pattern is set higher if this pattern identifies more important terms and fewer unimportant terms and vice versa. Note that it is possible that a same pattern may be associated with both important and unimportant terms. For example, the postfix expression “* operating system” may be used in the training documents 716 in conjunction with terms in the list of predefined important terms 712 and also used in conjunction with terms in the list of predefined unimportant terms 714. In this situation, the weight associated with the postfix pattern “* operating system” (represented by the expression Weight(1,0, “operating system”)) will take into account the number of times the postfix expression is used in conjunction with terms in the list of predefined important terms as well as the number of times the postfix expression is used in conjunction with terms in the list of predefined unimportant terms. One possible formula to determine the weight of a context patterns is: Weight(m, n, s)=Log(ImportantContext(m, n, s)+1)−Log(UnimportantContext(m, n, s)+1). Other weight determination formulas may be used in other embodiments. In the second phase of the context analysis process, the weighted context patterns are used to identify important terms in one or more documents identified by the user. Referring to FIG. 7B, in the first phase a computer system receives training data 750 and creates a set of context patterns 760, each context pattern having an associated weight. The computer system then applies the set of context patterns 760 to a document 780. In FIG. 7B, previously identified context patterns found within the document 780 are highlighted. Terms 790 associated with the context patterns are identified and each such term receives a weight based on the weights associated with the context patterns. For example, the term “Foobar” appears in the document twice, in association with two different patterns, the prefix pattern “Welcome to *” and the postfix pattern “* builds”, and the weight 1.2 assigned to “Foobar” is the sum of the two patterns' weights, 0.7 and 0.5. The other identified term “cars” has a weight of 0.8 because the matching prefix pattern “world's best *” has a weight of 0.8. In some embodiments the weight for each term is computed using a log transform, where the final weight is equal to log(initial weight+1). It is possible that the two terms “Foobar” and “cars” may not be in the training data 750 and may have never been encountered by the user before. Nevertheless, the context analysis method described above identifies these terms and adds them to the user's term-based profile. Thus, context analysis can be used to discover terms associated with a user's interests and preferences even when those terms are not included in a predefined database of terms. As noted, the output of context analysis can be used directly in constructing a user's term-based profile. Additionally, it may be useful in building other types of user profiles, such as a user's category-based profile. For example, a set of weighted terms can be analyzed and classified into a plurality of categories covering different topics, and those categories can be added to a user's category-based profile. After executing the context analysis on a set of documents identified by or for a user, the resulting set of terms and weights may occupy a larger amount of storage than allocated for each user's term-based profile. Also, the set of terms and corresponding weights may include some terms with weights much, much smaller than other terms within the set. Therefore, in some embodiments, at the conclusion of the context analysis, the set of terms and weights is pruned by removing terms having the lowest weights (A) so that the total amount of storage occupied by the term-based profile meets predefined limits, and/or (B) so as to remove terms whose weights are so low, or terms that correspond to older items, as defined by predefined criteria, that the terms are deemed to be not indicative of the user's search preferences and interests. In some embodiments, similar pruning criteria and techniques are also applied to the category-based profile and/or the link-based profile. As discussed above, a category-based profile can be created based on the information described in reference to FIG. 2. For example, the query terms previously submitted can be associated with particular categories of information. A user profile engine could analyze the previous search queries submitted by a user to determine particular categories of information that the user might be interested in and their respective weights. Such a user profile engine could analyze any of the sources of information described in reference to FIG. 2. In some embodiments, a user's profile is updated each time the user performs a search and selects at least one document from the search results to download or view. In some embodiments, the search engine builds a list of documents identified by the user (e.g., by selecting the documents from search results) over time, and at predefined times (e.g., when the list reaches a predefined length, or a predefined amount of time has elapsed), performs a profile update. When performing an update, new profile data is generated, and the new profile data is merged with the previously generated profile data for the user. In some embodiments, the new profile data is assigned higher importance than the previously generated profile data, thereby enabling the system to quickly adjust a user's profile in accordance with changes in the user's search preferences and interests. For example, the weights of items in the previously generated profile data may be automatically scaled downward prior to merging with the new profile data. In one embodiment, there is a date associated with each item in the profile, and the information in the profile is weighted based on its age, with older items receiving a lower weight than when they were new. In other embodiments, the new profile data is not assigned high importance than the previously generated profile data. The paragraph sampling and context analysis methods may be used independently or in combination. When used in combination, the output of the paragraph sampling is used as input to the context analysis method. It is further noted that the above-described methods used for creating user profiles, e.g., paragraph sampling and context analysis, may be also leveraged for determining the relevance of a candidate document to a user's preference. Indeed, the primary mission of a search engine is to identify a series of documents that are most relevant to a user's preference based on the search queries submitted by the user as well as the user's user profile. FIG. 8 illustrates several exemplary data structures that can be used to store information about a document's relevance to a user profile from multiple perspectives. For each candidate document, each identified by a respective DOC_ID, term-based document information table 810 includes multiple pairs of terms and their weights, category-based document information table 830 includes a plurality of categories and associated weights, and link-based document information table 850 includes a set of links and corresponding weights. The rightmost column of each of the three tables (810, 830 and 850) stores the rank (i.e., a computed score) of a document when the document is evaluated using one specific type of user profile. A user profile rank can be determined by combining the weights of the items associated with a document. For instance, a category-based or topic-based profile rank may be computed as follows. A user may prefer documents about science with a weight of 0.6, while he dislikes documents about business with a weight of −0.2. Thus, when a science document matches a search query, it will be weighted higher than a business document. In general, the document topic classification may not be exclusive. A candidate document may be classified as being a science document with probability of 0.8 and a business document with probability of 0.4. A link-based profile rank may be computed based on the relative weights allocated to a user's URL, host, domain, etc., preferences in the link-based profile. In one embodiment, term-based profile rank can be determined using known techniques, such as the term frequency-inverse document frequency (TF-IDF). The term frequency of a term is a function of the number of times the term appears in a document. The inverse document frequency is an inverse function of the number of documents in which the term appears within a collection of documents. For example, very common terms like “the” occur in many documents and consequently as assigned a relatively low inverse document frequency. When a search engine generates search results in response to a search query, a candidate document D that satisfies the query is assigned a query score, QueryScore, in accordance with the search query. This query score is then modulated by document D's page rank, PageRank, to generate a generic score, GenericScore, that is expressed as GenericScore=QueryScore*PageRank. This generic score may not appropriately reflect document D's importance to a particular user U if the user's interests or preferences are dramatically different from that of the random surfer. The relevance of document D to user U can be accurately characterized by a set of profile ranks, based on the correlation between document D's content and user U's term-based profile, herein called the TermScore, the correlation between one or more categories associated with document D and user U's category-based profile, herein called the CategoryScore, and the correlation between the URL and/or host of document D and user U's link-based profile, herein called the LinkScore. Therefore, document D may be assigned a personalized rank that is a function of both the document's generic score and the user profile scores. In one embodiment, this personalized score can be expressed as: PersonalizedScore=GenericScore*(TermScore+CategoryScore+LinkScore). FIGS. 9A and 9B represent two embodiments, both implemented in a client-server network environment such as the network environment 100 shown in FIG. 1. In the embodiment shown in FIG. 9A, the search engine 104 receives a search query from a client 102 at step 910 that is submitted by a particular user. In response, the search engine 104 may optionally generate a query strategy at step 915 (e.g., the search query is normalized so as to be in proper form for further processing, and/or the search query may be modified in accordance with predefined criteria so as to automatically broaden or narrow the scope of the search query). At step 920, the search engine 104 submits the search query (or the query strategy, if one is generated) to the content server 106. The content server identifies a list of documents that match the search query at step 920, each document having a generic score that depends on the document's page rank and the search query. In general, all the three operations (steps 910, 915 and 920) are conducted by the search engine system 107, which is on the server side of the network environment 100. There are two options on where to implement the operations following these first three steps. In some embodiments that employ a server-side implementation, the user's identification number is embedded in the search query. Based on the user's identification number, the user profile server 108 identifies the user's user profile at step 925. Starting from step 930, the user profile server 108 or the search engine 104 analyzes each document identified at step 920 to determine its relevance to the user's profile, creates a profile score for the identified document at step 935 and then assigns the document a personalized score that is a function of the document's generic and profile scores at step 940. At step 942, the user profile server 108 or the search engine 104 checks whether this the last one in the list of identified documents. If no, the system processes the next document in the list. Otherwise, the list of documents are re-ordered according to their personalized scores and then sent to the corresponding client from which the user submitted the search query. Embodiments using a client-side implementation are similar to the server-side implementation, except that after step 920, the identified documents are sent to the corresponding client from which the user submitted the query. This client stores the user's user profile and it is responsible for re-ordering the documents based upon the user profile. Therefore, this client-side implementation may reduce the server's workload. Further, since there is no privacy concern with the client-side implementation, a user may be more willing to provide private information to customize the search results. However, a significant limitation to the client-side implementation is that only a limited number of documents, e.g., the top 50 documents (as determined using the generic rank), may be sent to a client for re-ordering due to limited network bandwidth. In contrast, the server-side implementation may be able to apply a user's profile to a much larger number of documents, e.g., 1000, that match the search query. Therefore, the client-side implementation may deprive a user access to those documents having relatively low generic ranks, but significantly high personalized ranks. FIG. 9B illustrates another embodiment. Unlike the embodiment depicted in FIG. 9A, where the search query is not personalized before submitting the search query to the search engine 104, a generic query strategy is adjusted (step 965) according to the user's user profile to create a personalized query strategy. For example, relevant terms from the user profile may be added to the search query with associated weights. The creation of the personalized query strategy can be performed either on the client side or on the server side of the system. This embodiment avoids the network bandwidth restriction facing the previous embodiment. Finally, the search engine 104 submits the personalized query strategy to the content server 106 (step 970), and therefore the search results returned by the content server have already been ordered by the documents' personalized ranks (step 975). The profiles of a group of users with related interests may be combined together to form a group profile, or a single profile may be formed based on the documents identified by the users in the group. For instance, several family members may use the same computer to submit search queries to a search engine. If the computer is tagged with a single user identifier by the search engine, the “user” will be the entire family of users, and the user profile will be represent a combination or mixture of the search preferences of the various family members. An individual user in the group may optionally have a separate user profile that differentiates this user from other group members. In operation, the search results for a user in the group are ranked according to the group profile, or according to the group profile and the user's user profile when the user also has a separate user profile. It is possible that a user may switch his interests so dramatically that his new interests and preferences bear little resemblance to his user profile, or a user may be temporarily interested in a new topic. In this case, personalized search results produced according to the embodiments depicted in FIGS. 9A and 9B may be less favorable than search results ranked in accordance with the generic ranks of the documents in the search results. Additionally, the search results provided to a user may not include new websites among the top listed documents because the user's profile tends to increase the weight of older websites which the user has visited (i.e., older websites from which the user has viewed or downloaded web pages) in the past. To reduce the impact caused by a change in a user's preferences and interests, the personalized search results may be merged with the generic search results. In one embodiment, the generic search results and personalized search results are interleaved, with the odd positions (e.g., 1, 3, 5, etc.) of a search results list reserved for generic search results and the even positions (e.g., 2, 4, 6, etc.) reserved for personalized search results, or vice versa. Preferably, the items in the generic search results will not duplicate the items listed in the personalized search results, and vice versa. More generally, generic search results are intermixed or interleaved with personalized search results, so that the items in the search results presented to the user include both generic and personalized search results. In another embodiment, the personalized ranks and generic ranks are further weighted by a user profile's confidence level. The confidence level takes into account factors such as how much information has been acquired about the user, how close the current search query matches the user's profile, how old the user profile is, etc. If only a very short history of the user is available, the user's profile may be assigned a correspondingly low confidence value. The final score of an identified document can be determined as: FinalScore=ProfileScore*ProfileConfidence+GenericScore*(1−ProfileConfidence). When intermixing generic and personalized results, the fraction of personalized results may be adjusted based on the profile confidence, for example using only one personalized result when the confidence is low. Sometimes, multiple users may share a machine, e.g., in a public library. These users may have different interests and preferences. In one embodiment, a user may explicitly login to the service so the system knows his identity. Alternatively, different users can be automatically recognized based on the items they access or other characteristics of their access patterns. For example, different users may move the mouse in different ways, type differently, and use different applications and features of those applications. Based on a corpus of events on a client and/or server, it is possible to create a model for identifying users, and for then using that identification to select an appropriate “user” profile. In such circumstances, the “user” may actually be a group of people having somewhat similar computer usage patterns, interests and the like. Referring to FIG. 10, a personalized search engine system 1000 typically includes one or more processing units (CPU's) 1002, one or more network or other communications interfaces 1010, memory 1012, and one or more communication buses 1014 for interconnecting these components. The system 1000 may optionally include a user interface 1004, for instance a display 1006 and a keyboard 1008. Memory 1012 may include high speed random access memory and may also include non-volatile memory, such as one or more magnetic disk storage devices. Memory 1012 may include mass storage that is remotely located from the central processing unit(s) 1002. The memory 1012 preferably stores: an operating system 1016 that includes procedures for handling various basic system services and for performing hardware dependent tasks; a network communication module 1018 that is used for connecting the system 1000 to other servers or computers via one or more communication networks (wired or wireless), such as the Internet, other wide area networks, local area networks, metropolitan area networks, and so on; a system initialization module 1020 that initializes other modules and data structures stored in memory 1012 required for the appropriate operation of system 1000; a search engine 1022 for processing a search query, identifying and ordering search results according to the search query and a user's profile; a user profile engine 1030 for gathering and processing user information, such as the user information identified in FIG. 2, and creating and updating a user's user profile that characterizes the user's search preferences and interests; and data structures 1040, 1060 and 1080 for storing a plurality of user profiles. The search engine 1022 may further comprise: a generic rank module (or instructions) 1024 for processing a search query submitted by a user, identifying a list of documents matching the query and assigning each identified document a generic rank without reference to user specific information; a user profile rank module (or instructions) 1026 for correlating each of a plurality of documents identified by the generic rank module 1024 with the user's user profile and assigning the document a profile rank indicating the relevance of the document to the user's search preferences and interests; and a rank mixing module (or instructions) 1028 for combining the generic rank and the profile rank of an identified document into a personalized rank and re-ordering the list of documents according to their personalized ranks. In some embodiments, these modules 1024, 1026, 1028 may be implemented within a single procedure or in a set of procedures that reside within a single software module. The user profile engine 1030 may further comprise: a user information collection module 1032 for collecting and assorting various user information listed in FIG. 2; a document content extraction module 1034 for selecting and extracting content from the documents identified by the user, to identify content relevant to the user's interests, using techniques such as paragraph sampling (as discussed above); and a context analysis module 1036 for analyzing the content extracted by the document extraction module 1034 so as to identify terms that characterize a user's search preferences. Each data structure hosting a user profile may further comprise: a data structure 1042, 1062 or 1082 for storing a term-based user profile; a data structure 1044, 1064 or 1084 for storing a category-based user profile; and a data structure 1046, 1066 or 1086 for storing a link-based user profile. Ordering Placed Content in Accordance with a User Profile Placed content may be displayed to users of search services, email services, and a variety of other services provided via the Internet or other wide area networks. The following is a description of a system and method for ordering the placed content (e.g., within a browser window or other application window viewed by a user) so as to (A) maximize or at least improve the chances that the user will be interested in viewing the placed content, or (B) maximize or at least improve the revenue stream to a provider of the placed content, or (C) optimize or at least improve a metric associated with the delivery and ordering of the placed content. The system and method will first be described with respect to delivering placed content to users of a search engine, after which applications of the system and method to other internet services will be described. When search results are returned to a user in response to a search query, often times certain placed content is returned as well. Placed content is usually in the form of advertising, but could be any type of content related to the search query or to a document being sent to the user. Although the following description uses advertising content for the sake of illustration, any type of content where content providers compete or pay for placement is contemplated by some embodiments of the invention. The user's search query can be run against a repository of advertisements (ads) at the same time the search query is being run against a document repository. The ads returned from the search against the repository of ads (e.g., ads whose keywords match at least one term of the search query) are typically ordered by a score for each ad. The score is based on a click through rate (CTR) multiplied by a bid (e.g., a bid price). The ads having the highest scores are presented to the user. In some embodiments, a content provider may provide multiple, similar ads associated with the same bid. In this case, the various ads may be presented to users in a random fashion, or any other order. For instance, if a content provider provides a group of three ads to which a single bid on the term “hat” applies, whenever the group of ads has a high enough score to be included in a set of search results, one of the three ads in the group is selected (e.g., randomly, or in round robin order) and presented to the user. Advertisers may bid on different keywords or concepts through, for example, an auction in which advertisers place bids on certain search terms or phrases. For example, a maker of sails for sailboats may bid on the keyword “spinnaker” such that when that term appears in a search query, the advertiser's ad will appear in the list of potential ads to be presented to the user. The ad will be presented to the user if the ad's score is high enough. As mentioned above, the score is based on the CTR times the bid. An advertiser then pays for the ad based on its bid and based on the number of click throughs for the ad for a particular accounting period (e.g., the bid times the number of click throughs). In some embodiments, the auction may have characteristics of a “Dutch auction,” in which case the amount paid by the advertiser for a particular ad may be a modified or reduced bid multiplied by the number of click throughs for the particular accounting period. Improving an ad's CTR is one way to raise the score of the ad. Improving the CTR could be achieved, for example, by presenting an ad which appeals to users more than other ads. Alternatively, the advertiser may choose to increase his or her bid for a keyword or phrase associated with the ad in order to raise the ad's score. And, of course, the advertiser could both improve the CTR of the ad and increase its bid for a keyword associated with the ad. In some embodiments, the CTR for an ad is equal to the number of clicks on the ad divided by the number of impressions, that is, the number of times the ad is presented to users. Ads which are new do not typically have useful CTRs, because the number of impressions of the ad is too low for the value of the CTR to be a reliable indication of the ad's attractiveness to users. In such instances (e.g., when an ad has less than one thousand impressions) an initial CTR is provided by the system. The initial CTR for an ad may be a default value, such as an average CTR value. Alternately, the initial CTR may be selected based on the CTRs of other ads by the same advertiser, or may be based on the CTRs of some other set of ads having a defined relationship to the ad in question. It would be desirable to increase the likelihood that the user is presented with ads that are of interest to the user. Accordingly, ads which are in some way related to the user's profile are better candidates for presentation. One way to do this is to modify the ad's score based on the similarity of the ad to the user's profile. Referring back the broader term, “placed content,” FIG. 11 illustrates one embodiment for providing placed content with search results. Initially a search query is received (1102) at a search engine, for example. The search query may identify the user submitting the search query, for instance by including an identifier of the client computer or client process submitting the search query. Alternately, the identity of the user may be known due to a prior login to a service, or a cookie or other suitable method. The user's profile is obtained (1104) from a database or repository of user profiles. In one embodiment, the user's profile is a category profile. While the following description uses the category profile, one of ordinary skill in the art will readily recognize that the concepts herein can applied to other types of profiles. While the search engine processes the search query so as to obtain search results (1106), a placed content server identifies one or more placed content items (herein called potential placed content) that match or are relevant to the search query (1108). In other embodiments, the placed content server may provide the placed content based on what document is being provided to the user, be it as a result of a search or a specifically requested document. In that embodiment the placed content server determines which of the placed content is relevant to the document being presented to the user. In other embodiments, the placed content server may provide the placed content based on the contents of the one or more documents being presented as the search results. Each potential placed content has a profile associated with it. In one embodiment, the profile is in the form of a category profile containing pairs of categories and weights. The profile could be created by, for example, extracting key terms from the placed content and associating them with various categories and assigning respective weights. For each potential placed content, a profile of the potential placed content is compared to the user's profile (1110). The user's profile is compared to the placed content profile to obtain a similarity score. The similarity score is then used to modify the placed content's ranking. If one considers each of the profiles as a vector, then one of ordinary skill in the art will recognize various mathematical ways to compare the profiles. For example, the similarity score could be determined by taking each category in the user's profile and determining a mathematical distance between it and each category of the placed content's profile and then multiplying by the respective weights. One way to represent this calculation is by the following formula: similarity score = ∑ i = 0 n - 1 ∑ j = 0 m - 1 distance ( category ( i ) , category ( j ) ) * weight ( i ) * weight ( j ) where n represents the number of categories in the user's profile and m represents the number of categories in the placed content's profile; distance(category(i), category(j)) represents a mathematical distance between category(i) and category(j); and weight(i) and weights) represent the weights associating with category(i) and category(j), respectively. Another, more general, way to represent computation of the similarity score is: similarity score=function (user profile, content profile) where “function” is any suitable function of the user profile and the content profile of a particular placed content item. When the user and content profiles are category profiles, the computation of the similarity score may be represented as: similarity score = function ( user profile categories , user profile weights , content profile categories , content profile weights ) where “function” is any suitable function of the vector of user profile categories and weights and the vector of content profile categories and weights. A somewhat more specific example of a computation of the similarity score, which differs from the double sum computation shown above, is: similarity score = ∑ i Max j ( function ( category ( i ) , category ( j ) , weight ( i ) , weight ( j ) ) where “Maxj” represents the maximum value of the function for all valid values of j, and the “function” is any suitable function of the user and content profile categories and weights. In some embodiments the similarity score is normalized to a particular range to create a scaling factor. For example, the similarity score may be normalized so as to fall in the inclusive range of 0 to 1, or 0 to 2. Higher similarity scores indicate that the profiles are more closely related than profiles whose comparisons result in lower similarity scores. In some embodiments, the normalized similarity score is used as the scaling factor. In other embodiments, the scaling factor is determined by mapping either the similarity score or the normalized similarity score to a corresponding scaling factor in accordance with either a scaling factor mapping function or a scaling factor lookup table. In one embodiment, a set of N predefined scaling factors (sometimes called subfactors) are stored in a scaling factor lookup table, with each scaling factor corresponding to a respective range of similarity score values. In this exemplary embodiment, N is an integer greater than one, and preferably greater than three. The similarity score for a particular placed content is mapped to a “bin,” for example by multiplying or dividing the similarity score by a predefined number, rounding the result up or down to the closest integer to produce a bin number, and then mapping the resulting bin number to a scaling factor by using the bin number as an index into the scaling factor lookup table. The range of scaling factors can vary from one implementation to another. The use of either a scaling factor mapping function or a scaling factor lookup table permits a great deal of flexibility in relating the similarity score to the scaling factor. For example, one could create a scaling factor mapping function or a scaling factor lookup table that adjusts downward the CTRs of placed content having very low similarity scores as well as placed content having very high similarity scores. In some embodiments, the scaling factor associated with the maximum similarity score is less than the scaling factor associated with a mid-point similarity score, where the mid-point could be either the mean or median of the similarity scores. Alternately, the mid-point can be any identified point between the minimum and maximum similarity scores. In some embodiments, the scaling factor associated with the maximum similarity score is greater than the scaling factor associated with a mid-point similarity score, but is less than the maximum scaling factor associated with a scaling factor mapping function or a scaling factor lookup table. When viewing the scaling factor mapping function for values of the similarity score going from a minimum score to a maximum score, the scaling factor will typically initially increase from a low value associated with the minimum score until it reaches a peak scaling factor value, and will then decrease until the similarity score reaches a maximum value. In some embodiments, the scaling factor corresponding to a similarity score is determined in accordance with statistical information relating similarity scores to click through rates. In particular, click through rates by users can be statistically correlated to similarity scores for the users and the placed content items. For instance, separate click through rates can be determined for each range in a set of N ranges of similarity scores by collecting data on impressions, click throughs and the similarity scores associated with each impression and click through. Based on those click through rates, a set of N scaling factors can be generated for storing in a scaling factor lookup table. Alternately, the collected statistical information can be used to generate a scaling factor mapping function, for instance by using curve fitting techniques. In some embodiments, the respective scaling factor for each identified placed content is multiplied by the CTR of the placed content to provide a modified CTR, to reflect the increased likelihood that the user would be interested in the placed content (1112 of FIG. 11). More specifically, the score for each placed content that matches the search query (e.g., by having at least one keyword that matches a term of the search query) is computed as: score=scaling factor×CTR×bid. The placed content items are then ranked or ordered based on their respective scores (1114) and the placed content items having the highest scores are provided to the user (1116), for example by being sent to a browser application on the user's computer. In some embodiments, the placed content items having the H highest scores (where H is an integer greater one) may be merged (1118) with search results (sometimes called the primary search results) obtained from execution of the search query against a database. For instance, when the placed content comprises ads, one or more of the ads having the highest scores may be displayed above, below and/or to the side of the primary search results. In some embodiments, the scores for placed content items are based on the similarity scores produced using a user profile and a bid, but are not based on a click through rate. For instance, in some embodiments click through rates for the placed content items may not be available. As a result, in such embodiments action 1112 either does not occur, or is replaced by a different scoring adjustment or scoring computation action. In some other embodiments, the scores for placed content items are based on the similarity scores produced using a user profile and a click through rate, but not a bid. And in yet other embodiments, the scores for placed content items are based on the similarity scores produced using a user profile, but those scores are not based on either the bid or a click through rate. When the placed content scores take into account a user profile, but not a bid, the ordering of the placed content is optimized or improved with respect to placed content that is likely to be of interest to the user, without regard to potential economic benefits of other orderings of the placed content items. The system and method described above can also be used in systems other than search engine systems. For instance, in an email system or in virtually any other system for providing services via the Internet or other wide area network that displays a document or other content to a user or subscriber, placed content may be also be selected and displayed to the user. The placed content may be selected based on the keywords associated with the placed content matching the content of a displayed document or set of documents, or it may be based on the other selection criteria. The selected placed content items are then ordered based on similarity of the user profile and profiles of the selected placed content items, as described above. The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. | <SOH> BACKGROUND OF THE INVENTION <EOH>Search engines provide a powerful source of indexed documents from the Internet (or an intranet) that can be rapidly scanned in response to a search query submitted by a user. Such a query is usually very short (on average about two to three words). As the number of documents accessible via the Internet grows, the number of documents that match the query may also increase. However, not every document matching the query is equally important from the user's perspective. As a result, a user is easily overwhelmed by an enormous number of documents returned by a search engine, if the engine does not order the search results based on their relevance to the user's query. One approach to improving the relevance of search results to a search query is to use the link structure of different web pages to compute global “importance” scores that can be used to influence the ranking of search results. This is sometimes referred to as the PageRank algorithm. A more detailed description of the PageRank algorithm can be found in the article “The Anatomy of a Large-Scale Hypertextual Search Engine” by S. Brin and L. Page, 7 th International World Wide Web Conference, Brisbane, Australia and U.S. Pat. No. 6,285,999, both of which are hereby incorporated by reference as background information. An important assumption in the PageRank algorithm is that there is a “random surfer” who starts his web surfing journey at a randomly picked web page and keeps clicking on the links embedded in the web pages, never hitting the “back” button. Eventually, when this random surfer gets bored of the journey, he may re-start a new journey by randomly picking another web page. The probability that the random surfer visits (i.e., views or downloads) a web page depends on the web page's page rank. From an end user's perspective, a search engine using the PageRank algorithm treats a search query the same way no matter who submits the query, because the search engine does not ask the user to provide any information that can uniquely identify the user. The only factor that affects the search results is the search query itself, e.g., how many terms are in the query and in what order. The search results are a best fit for the interest of an abstract user, the “random surfer”, and they are not be adjusted to fit a specific user's preferences or interests. In reality, a user like the random surfer never exists. Every user has his own preferences when he submits a query to a search engine. The quality of the search results returned by the engine has to be evaluated by its users' satisfaction. When a user's preferences can be well defined by the query itself, or when the user's preference is similar to the random surfer's preference with respect to a specific query, the user is more likely to be satisfied with the search results. However, if the user's preference is significantly biased by some personal factors that are not clearly reflected in a search query itself, or if the user's preference is quite different from the random user's preference, the search results from the same search engine may be less useful to the user, if not useless. As suggested above, the journey of the random surfer tends to be random and neutral, without any obvious inclination towards a particular direction. When a search engine returns only a handful of search results that match a query, the order of the returned results is less significant because the requesting user may be able to afford the time to browse each of them to discover the items most relevant to himself. However, with billions of web pages connected to the Internet, a search engine often returns hundreds or even thousands of documents that match a search query. In this case, the ordering of the search results is very important. A user who has a preference different from that of the random surfer may not find what he is looking for in the first five to ten documents listed in the search results. When that happens, the user is usually left with two options: (1) either spending the time required to review more of the listed documents so as to locate the relevant documents; or (2) refining the search query so as to reduce the number of documents that match the query. Query refinement is often a non-trivial task, sometimes requiring more knowledge of the subject or more expertise with search engines than the user possesses, and sometimes requiring more time and effort than the user is willing to expend. For example, assume that a user submits to a search engine a search query having only one term “blackberry”. Without any other context, on the top of a list of documents returned by a PageRank-based search engine may be a link to www.blackberry.net, because this web page has the highest page rank. However, if the query requester is a person with interests in foods and cooking, it would be more useful to order the search results so as to include at the top of the returned results web pages with recipes or other food related text, pictures or the like. It would be desirable to have a search engine that is able to reorder its search results, or to otherwise customize the search results, so as to emphasize web pages that are most likely to be of interest to the person submitting the search query. Further, it would be desirable for such a system to require minimal input from individual users, operating largely or completely without explicit input from the user with regard to the user's preferences and interests. Finally, it would be desirable for such a system to meet users' requirements with respect to security and privacy. | <SOH> SUMMARY <EOH>In a method of personalizing placed content, an interest of a user is determined, and a user profile associated with the user is accessed. A set of placed content that matches the interest of the user is identified, and the set of placed content is ordered in accordance with the user profile. In one aspect of the invention, a search engine utilizes user profiles to customize search results, which may include placed content as well as other or general content. A user profile comprises multiple items that characterize a user's interests or preferences. These items are extracted from various information sources, including previous search queries submitted by the user, links from or to the documents identified by the previous queries, sampled content from the identified documents as well as personal information implicitly or explicitly provided by the user. When the search engine receives a search query from a user, it identifies a set of placed content that matches the search query. Each placed content is associated with a rank based at least in part a similarity of the placed content to the user profile. The placed content items are then ordered according to their ranks. The present invention, including user profile construction and search results re-ordering and/or scoring, can be implemented on either the client side or the server side of a client-server network environment. | 20040713 | 20100406 | 20051027 | 93551.0 | 0 | LE, THU NGUYET T | PERSONALIZATION OF PLACED CONTENT ORDERING IN SEARCH RESULTS | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,890,916 | ACCEPTED | Optical disk and optical disk recording and reproducing device | An optical disk includes a plurality of disk sheets which are laminated, and each of which has a recording face on one of the surfaces and a flat back surface, wherein the plurality of disk sheets are laminated by adhesive layers in such a manner that between adjacent two disk sheets, a back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces the disk surface of the other disk sheet. The foregoing structure realizes an optical disk of desirable recording/reproducing characteristics, which is flat and has a fixed interval between recording faces, and which permits the problems of coma aberration, spherical aberration, etc., to be suppressed. | 1. An optical disk including a plurality of disk sheets which are laminated, and each of which has a recording face on one of surfaces, wherein: said plurality of disk sheets are laminated in such a manner that between adjacent two disk sheets, a back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces a disk surface of the other disk sheet. 2. The optical disk as set forth in claim 1, wherein: said back surface is formed in a plane surface. 3. The optical disk as set forth in claim 1, wherein: between the disk substrate and the disk sheet and between adjacent disk sheets, an adhesive layer made up of ultraviolet ray curing resin is formed. 4. The magnetic recording medium as set forth in claim 1, wherein: the disk sheet is formed thinner than the disk substrate. 5. The magnetic recording medium as set forth in claim 1, wherein: a protective layer is formed so as to cover the disk sheet laminated at position most apart from the disk substrate. 6. The disk as set forth in claim 5, wherein: the protective layer is made up of ultraviolet ray curing resin. 7. The optical disk as set forth in claim 5, wherein: the protective layer is a protective sheet bonded to an upper most disk sheet. 8. The optical disk as set forth in claim 1, wherein: a recording face of the upper most disk sheet laminated at position most apart from the disk substrate is formed on the side of the disk substrate; and the upper most disk sheet is formed thicker than other disk sheet. 9. An optical disk, comprising: a disk substrate; a disk sheet layer made up of plurality of layers laminated on said disk substrate, each having a recording face, wherein an inner diameter of said disk sheet layer is larger than an inner diameter of said disk substrate. 10. An optical disk, comprising: a disk substrate; a disk sheet layer made up of plurality of layers laminated on said disk substrate, each having a recording face, wherein an outer diameter of said disk sheet layer is smaller than an outer diameter of said disk substrate. 11. The optical disk as set forth in claim 9, wherein: said plurality of disk sheets of said disk sheet layer are laminated in such a manner that the further from the disk substrate in a laminating direction, the larger is the inner diameter of the disk sheet. 12. The optical disk as set forth in claim 9, wherein: said plurality of disk sheets of said disk sheet layer are laminated in such a manner that the further from the disk substrate in a laminating direction, the smaller is the outer diameter of the disk sheet. 13. The optical disk as set forth in claim 9, wherein: a protective layer is formed on the upper surface of the disk sheet formed at position most apart from said disk substrate in a direction in which said plurality of disk sheets are laminated. 14. The optical disk as set forth in claim 10, wherein: a protective layer is formed on the upper surface of the disk sheet formed at position most apart from said disk substrate in a direction in which said plurality of disk sheets are laminated. 15. An optical disk, comprising: a disk substrate; and a disk sheet layer made up of plurality of layers laminated on said disk substrate, each having a recording face, wherein a first region of said disk substrate where said disk substrate is formed is thinner than a second region other than said first region. 16. The optical disk as set forth in claim 15, wherein: said second region of said disk substrate may be an inner circumferential region located inside a predetermined radius, an outer circumferential region located outside the predetermined radius, or both the inner circumferential region and said outer circumferential region. 17. An optical disk, comprising: a disk substrate; and a disk sheet layer made up of plurality of layers laminated on said disk substrate, each having a recording face, wherein an inner circumferential region corresponding to the region corresponding to the predetermined radius, an outer circumferential region outside the predetermined radius, or both the inner circumferential region and said outer circumferential region of said disk substrate is formed thicker than other region of said disk substrate. 18. An optical recording device, wherein: information is recorded on the optical disk as set forth in claim 1 by projecting a light beam to be focused thereon. 19. An optical recording device, wherein: information is recorded on the optical disk as set forth in claim 9 by projecting a light beam to be focused thereon. 20. An optical recording device, wherein: information is recorded on the optical disk as set forth in claim 10 by projecting a light beam to be focused thereon. 21. An optical recording device, wherein: information is recorded on the optical disk as set forth in claim 15 by projecting a light beam to be focused thereon. 22. An optical recording device, wherein: information is recorded on the optical disk as set forth in claim 17 by projecting a light beam to be focused thereon. 23. An optical reproducing device, wherein: information is recorded on the optical disk as set forth in claim 1 by projecting a light beam to be focused thereon. 24. An optical reproducing device, wherein: information is recorded on the optical disk as set forth in claim 9 by projecting a light beam to be focused thereon. 25. An optical reproducing device, wherein: information is recorded on the optical disk as set forth in claim 10 by projecting a light beam to be focused thereon. 26. An optical reproducing device, wherein: information is recorded on the optical disk as set forth in claim 15 by projecting a light beam to be focused thereon. 27. An optical reproducing device, wherein: information is recorded on the optical disk as set forth in claim 17 by projecting a light beam to be focused thereon. | This Non-provisional application claims priority under 35 U.S.C. § 119(a) on patent application Ser. No. 2003/197392 filed in Japan on Jul. 15, 2003, and patent application Ser. No. 2003/388193 filed in Japan on Nov. 18, 2003 the entire contents of which are hereby incorporated by reference. FIELD OF THE INVENTION The present invention relates to an optical disk having a plurality of recording faces and an optical disk recording and reproducing device adopting such optical disk. BACKGROUND OF THE INVENTION A conventional manufacturing method of an optical disk 200 having a plurality of recording faces will be explained in reference to FIGS. 25(a) to 25(c), and FIGS. 26(a) and 26(c) (see, for example, Japanese Laid-Open patent Japanese Unexamined Patent Publication No. 2001-134981 (Tokukai 2001-134981 published on May 18, 2001). Firstly, a first substrate 100 having formed thereon recording pits 101 is formed by the injection molding method or the 2P method, and then a first reflective film 102 is formed so as to cover the first pits. 101 (see FIG. 25(a)), thereby forming a recording face 201. Next, on the first substrate 100 having formed thereon the first reflective film 102, an original substrate 104 is placed with a predetermined interval (see FIG. 25(b)). On this original substrate 104, formed are second bits 105 having recorded thereon different information from that of the first pits 101 (see FIG. 25(b)). Thereafter, a recording layer 103 is formed by filling the space between the first substrate 100 and the original substrate 104 with ultraviolet ray curing resin, and hardening the ultraviolet ray curing resin by projecting thereon an ultraviolet ray (FIG. 25 (c)). Next, after removing the original substrate 104, a second reflective film 106 is formed on the first recording layer 103 having copied thereto the second recording pits 105 are copied, thereby forming a recording face 205. The first substrate 100 on which the recording face 201 and the recording face 205 are formed, and a second substrate 107 on which a recording face 208 having formed thereon the third pits 108 and the third reflective film 109 is formed are placed with a predetermined interval in between so that the recording face 205 and the recording face 208 face each other (FIG. 26b). The space between the first substrate 100 and the second substrate 107 is filled with ultraviolet ray curing resin 110. Then, the recording layer 110 is hardened by projecting thereon an ultraviolet ray so as to connect the first substrate 100 and the second substrate 107 together (see FIG. 26 (c)). In the foregoing process, an optical disk 200 including the first recording face 201 having formed thereon the first bits 101, a recording face 205 having formed thereon the second pits 105, and the recording face 208 having formed thereon the third pits 108 can be manufactured. In the foregoing conventional example, explanations will be given through the case of the method of forming an optical disk with the three-layered recording face. However, by repeating the foregoing copying process, it is possible to form an optical disk having a greater number of recording faces. However, the optical disk 200 formed by the foregoing manufacturing process has the following problems as will be explained below. a) The optical disk 200 cannot be maintained flat. b) An interval between adjacent recording faces cannot be controlled with high precision. Problem a) Generally, it is necessary to form the first recording layer 103 and the second recording layer 110 in a thickness of around 10 μm for the purpose of preventing an interlayer cross light or interlayer crosstalk generated when recording or reproducing. In the foregoing method, when forming the first recording layer 103, the space between the first substrate 100 and the original substrate 104 is filled with liquid ultraviolet ray curing resin, and hardening the resin with an application of an ultraviolet ray. Here, a problem arises in that the recording layer 103 shrinks in the hardening process with an application of the ultraviolet ray. The foregoing problem of shrinkage arises also in the process of forming the recording layer 110. For example, in the case where the recording layer 103 and the recording layer 110 are formed in a thickness of 20 μm, the optical disk 200 is tilted to a large extent due to the shrinkage when hardening, and it becomes no longer possible to maintain the disk flat. Furthermore, when forming other recording layer 103 in addition to the recording layers 103 and 110, the optical disk 200 would be tilted to a larger extent. When adopting the foregoing disk 200 with the foregoing problems of a large tilt which makes it difficult to maintain the disk 200 flat, coma aberration of the light beam would be increased, which makes it difficult to form a desirable light beam spot, thereby deteriorating the recording/reproducing characteristics. Problem b) According to the foregoing manufacturing method, in the process of filling the space between the first substrate 100 and the original substrate 104 with liquid ultraviolet ray curing resin, the original substrate 104 and the first substrate 100 are liable to be partially distorted. The foregoing partial distortion results in uneven interval between the original substrate 104 and the first substrate 100, i.e., the thickness of the first recording layer 103. Furthermore, in the process of connecting the substrates together as shown in FIG. 26(c), it is necessary to carry out the process of hardening the second recording layer 100 in the state different from that shown in FIG. 25(c). Namely, in the state shown in FIG. 25(c), the ultraviolet ray curing resin filled in the space between the first substrate 100 (generally made of plastics) and the original substrate 104 (generally metal plate or glass plate). In contrast, in the state shown in FIG. 26(c), the ultraviolet ray curing resin filled in the space between the first substrate 100 and the second substrate 107 (generally made of plastic) is hardened. As described, when carrying out the process of hardening the recording layers under different conditions, such hardening conditions as a rise in temperatures when hardening, etc., are liable to change, and it is difficult to form the first recording layer 103 and the second recording layer 110 in the same thickness. As described, in the foregoing conventional manufacturing process, the thickness of each recording layer becomes partially uneven, or the thickness between recording layers becomes uneven, which results in such problem that the interval between the adjacent recording faces cannot be controlled with high precision. When adopting the foregoing optical disk manufactured by the conventional method, in which an interval between the recording faces varies, a spherical aberration occurs in the light beam when recording/reproducing, resulting in the problem of increasing a focused beam spot diameter or deterioration in recording/reproducing characteristics. SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical disk which is flat and has a fixed interval between recording faces, and which permits the problems of coma aberration, spherical aberration, etc., to be suppressed, and an optical disk recording/reproducing device adopting the same. In order to achieve the foregoing object, an optical disk of the present invention is characterized by including: a plurality of disk sheets which are laminated, and each of which has a recording face on one of the surfaces, wherein: the plurality of disk sheets are laminated in such a manner that between adjacent two disk sheets, a back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces the disk surface of the other disk sheet. According to the foregoing structure of the optical disk, a plurality of disk sheets, each having a recording face, are laminated. With this structure, as compared to the conventional optical disk formed by hardening the ultraviolet ray curing resin on a substrate in sequence, a shrinkage is not liable to occur in the process of forming recording faces, and thus the disk can be maintained flat. Furthermore, as a disk sheet of a uniform thickness without a partial distortion can be selected as a disk sheet to be laminated, an interval between recording faces of the adjacent disk sheets can be maintained constant. In the optical disk, when recording or reproducing, the problem of generating coma aberration or spherical aberration of the light beam can be suppressed, thereby realizing desirable recording/reproducing characteristics. Furthermore, with the structure wherein a plurality of disk sheets are laminated in such a manner that between adjacent two disk sheets, the back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces the disk surface of the other disk sheet, an interval between adjacent recording faces can be more surely maintained constant. In order to achieve another object, another optical disk in accordance with the present invention is characterized by including: a disk substrate; a disk sheet layer made up of plurality of layers laminated on the disk substrate, each having a recording face, wherein an inner diameter of the disk sheet layer is larger than an inner diameter of the disk substrate. According to the foregoing structure wherein the inner diameter of the disk sheet layer is larger than the inner diameter of the disk substrate, the disk sheet layer can be prevented from being separated from the disk substrate or from the adjacent disk sheet layer at the central hole of the optical disk, and thus the effect of providing a highly reliable optical disk can be achieved. Namely, in the case where the inner diameter of the disk sheet layer is equal to the inner diameter of the disk substrate, or the inner diameter of the disk sheet layer is smaller than the inner diameter of the disk substrate, when fixing and holding the optical disk, a jig contacts the central hole of the disk sheet layer, which causes a separation of the disk sheet. In contrast, in the case where the inner diameter of the disk sheet layer is larger than the inner diameter of the disk substrate, the jig contacts only the central hole of the disk substrate, and does not contact the central hole of the disk sheet layer, thereby suppressing the problem of the separation of the disk sheet. Another optical disk of the present invention is characterized by including: a disk substrate; and a disk sheet layer made up of plurality of layers laminated on the disk substrate, each having a recording face, wherein an outer diameter of the disk sheet layer is smaller than an outer diameter of the disk substrate. According to the foregoing structure, the outer diameter of the disk sheet layer is smaller than the outer diameter of the disk substrate, the disk sheet layer can be prevented from being separated from the disk substrate or from the adjacent disk sheet layer at an outer circumference of the optical disk, and thus the effect of providing a highly reliable optical disk. Namely, in the case where the outer diameter of the disk sheet layer is equal to the outer diameter of the disk substrate or the outer diameter of the disk sheet layer is larger than the outer diameter of the disk substrate, when fixing and holding the optical disk, the disk sheet layer contacts a jig, which causes a separation of the disk sheet. In contrast, in the case where the outer diameter of the disk sheet layer is smaller than the outer diameter of the disk substrate, the jig contacts only the outer circumference of the disk substrate, and does not contact the outer circumference of the disk sheet layer, thereby suppressing the problem of the separation of the disk sheet. Another optical disk of the present invention is characterized by including: a disk substrate; and a disk sheet layer made up of plurality of layers laminated on the disk substrate, each having a recording face, wherein a first region of the disk substrate where said disk substrate is formed is thinner than a second region other than said first region. With this structure, the second region of the disk substrate may be an inner circumferential region located inside a predetermined radius, an outer circumferential region located outside the predetermined radius, or both the inner circumferential region and the outer circumferential region. The second region of the disk substrate may be an inner circumferential region located inside a predetermined radius, an outer circumferential region located outside the predetermined radius, or both the inner circumferential region and the outer circumferential region. According to the foregoing structure, by setting the thickness of the second region, i.e., the inner circumferential region located inside the predetermined radius, the outer circumferential region located outside the predetermined radius, or both the inner circumferential region and the outer circumferential region, thicker than the first region where the disk sheet layer is formed, it is possible to increase the mechanical strength of the inner circumferential region, or the outer circumferential region or both the inner circumferential region and the outer circumferential region, thereby suppressing a damage of the disk substrate when being accidentally dropped or set in the recording/reproducing device. With a combined use of the optical disk and the recording/reproducing device of the optical disk, the present invention permits information to be recorded/reproduced on or from the optical disk of multilayered structure having a plurality of recording faces in the disk sheet layer, thereby realizing a large capacity optical disk. For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view which explains the structure of an optical disk in accordance with the present invention. FIG. 2 is a cross-sectional view which explains the structure of the optical disk. FIG. 3(a) and FIG. 3(b) are perspective views which explain the structure of a recording face of a disk sheet of the present invention. FIG. 4(a) and FIG. 4(b) are perspective views which explain the structure of a recording face of a disk sheet of the present invention. FIG. 5 is a cross-sectional view which explains the structure of the optical disk. FIG. 6 is an explanatory view which shows the structure of an optical disk recording device or reproducing device of the present invention. FIG. 7 is a cross-sectional view which explains another structure of the optical disk of the present invention. FIG. 8 is a cross-sectional view which explains still another structure of the optical disk of the present invention. FIG. 9 is a cross-sectional view which explains still another structure of the optical disk of the present invention. FIG. 10 is a cross-sectional view which explains still another structure of the optical disk of the present invention. FIG. 11 is a cross-sectional view which explains still another structure of the optical disk of the present invention. FIG. 12 is a cross-sectional view which explains a method of forming a disk sheet in accordance with the present invention. FIG. 13 is a cross-sectional view which explains another method of forming a disk sheet in accordance with the present invention. FIG. 14 is a cross-sectional view which explains a device for forming a reflective film or a recording film on the disk sheet. FIG. 15 is a cross-sectional view which explains another device for forming a reflective film or a recording film on the disk sheet. FIG. 16 is a perspective view which explains the structure of an optical disk in accordance with the present invention. FIG. 17 is a cross-sectional view which explains the structure of the optical disk in accordance with the present invention. FIG. 18 is a perspective view which explains the structure of another optical disk in accordance with the present invention. FIG. 19 is a cross-sectional view which explains the structure of the optical disk. FIG. 20 is a cross-section view which explains still another structure of the optical disk of the present invention. FIG. 21 is a cross-section view which explains still another structure of the optical disk of the present invention. FIG. 22 is a cross-section view which explains still another structure of the optical disk of the present invention. FIG. 23 is a cross-section view which explains still another structure of the optical disk of the present invention. FIG. 24 is a cross-sectional view which explains one example of the optical disk. FIGS. 25(a) to 25(c) are cross-sectional views which explain a conventional method of forming a conventional optical disk forming method. FIGS. 26(a) to 26(c) are cross-sectional views which explain a conventional method of forming a conventional optical disk forming method. DESCRIPTION OF THE EMBODIMENTS The following descriptions will explain an optical disk, an optical disk forming method and an optical disk device of the present invention will be explained in reference to Figures. [Technical Concepts of the Present Invention) As shown in FIG. 1, an optical disk 1 in accordance with the present invention includes a disk substrate 5, and a disk sheet layer 4 formed on the disk substrate 5. The disk substrate 5 is made up of layered plurality of disk sheets 6 (see FIG. 2). The optical disk 1 may be arranged so as to form an inner circumferential hole 2 for centering. FIG. 2 shows a cross-sectional view of the optical disk 1. FIG. 2 shows the optical disk 1 enlarged only in its thickness direction. As illustrated in FIG. 2, the optical disk 1 is arranged such that a plurality of disk sheets 6 that are laminated using an adhesive layer 7 are formed as the disk sheet layer 4. Namely, the disk sheet layer 4 has such structure that the disk sheets 6 and the adhesive layers 7 are alternately laminated. FIGS. 3(a), 3(b), 4(a), and 4(b) explain a recording face 6a of the optical disk 1. As illustrated in these figures, on the surface of the disk sheet 6, formed are recessed pits 8 (see FIG. 3(a)), and tracks 9 made up of lands 9a and 9b (see FIG. 4(a)). In the present embodiment, the surface on the side where a pattern of recessions and protrusions of the pits 8 and the tracks 9 of the disk sheet 6 is used as a recording face 6a of the disk sheet 6, and the surface on the opposite side of the recording face 6a is defined to be a back surface 6b of the disk sheet 6. Here, in order to ensure accurate tracking, the level difference between the recessions and protrusions of pits 8, it is preferable that the level difference between the lands 9a and the grooves 9b of the track 9 be set in a range of from 20 nm to 100 nm to ensure an accurate tracking. FIG. 5 is an enlarged cross-sectional view of the optical disk 1. As illustrated in FIG. 5, the optical disk 1 includes the disk substrate 5 having a flat surface and a plurality of disk sheets 6 are laminated on the flat surface. Each of the plurality of the disk sheets 6 is arranged such that one of the surfaces serves as the recording face 6a and the other surface, i.e., the back surface 6a has a flat face. These plurality of the disk sheets 6 are laminated by bonding together by means of the adhesive layers 7 in such a manner that the surface of the disk substrate 5 faces the recording face 6a of the disk sheet 6, and between two adjacent disk sheets 6, the recording face 6a of one of the disk sheets 6 faces the back surface 6b of the other disk sheet 6. Namely, the disk sheet layer 4 is made up of the disk sheets 6, each having a flat back surface 6b, and the adhesive layers 7 which are alternately laminated so that respective recording faces 6a of the disk sheets 6 face the disk substrate. In this state, a light beam 13 is projected onto the respective recording faces 6a of the disk sheets 6 to be focused thereon by respective objective lens 14, and the focusing is adjusted so that the light beam 13 can be focused on each recording race 6a. The focused light beam 13 is subjected to tracking along the bits 8 or the tracks 9 (see FIGS. 3 and 4) with rotations of the optical disk 1, thereby carrying out recording and reproducing operations. FIG. 6 is a view schematically showing the structure of a disk device for recording and/or reproducing on/from the optical disk 1. The optical disk 1 is caught by a spindle 15 in the state where the centering is performed by the inner circumferential hole 2, and the optical disk 1 is subjected to the rotation driving. On the other hand, the light beam 13 is controlled by the optical pickup 16. Namely, the optical pickup 16 is made up of a light beam source, an optical detector, a focusing optical system, a tracking optical system, and an objective lens 14 for focusing the light beam. By means of this optical pickup 16, the focusing is performed with respect to the recording face 6a (see FIG. 5) of a specific disk sheet 6 in the disk sheet layer 4 formed on the disk substrate 5, and further the tracking is performed with respect to the pits 8 or the tracks 9 (see FIGS. 3 and 4). The foregoing optical disk device includes a driving control circuit 18 for controlling the rotation driving of the optical disk 1, the access control of the optical pickup 16, the focusing control and the tracking control, and a recording and/or reproducing control circuit 17 for controlling the light beam intensity, the detection of recording signals and/or the control of recording signals. In order to reduce the spherical aberration generated by laminating the disk sheet 6, an interval between a pair of the objective lens (relay lens) 14 stored in the optical pickup 16 with respect to each recording face 6a. The foregoing optical disk 1 and the reproducing device and the recording device of the optical disk, it is possible to reproduce from or record on the optical disk 1 of a multi-layered structure which includes a plurality of recording faces 6a in the disk sheet layer 4, thereby realizing a large volume optical disk device. In reference to FIG. 5, explanations have been given through the case where a light beam is incident from the side of the disk sheet 6. However, it is also possible to record or reproduce by projecting a light beam from the side of the disk substrate 5. However, a problem arises in that when an attempt is made to make a focused beam spot of the optical beam 13 smaller by adopting the objective lens 14 of a large numerical aperture to realize still higher density recording/reproducing, a coma aberration of the light beam may be generated even with a slight tilt of the optical disk 1. Particularly when adopting the objective lens 14 having an NA of not less than 0.70, the adverse effect of the coma aberration becomes extremely large. Therefore, when a light beam is incident from the disk substrate 5, in particular, it is desirable that the disk sheet 6 or the disk substrate 5 be made thinner. According to the present invention, the optical disk 1 of large recording capacity can be realized by laminating a plurality of relatively thin disk sheets 6 while maintaining the flatness of the optical disk 1. (The Structure of the Recording Face 6a) The optical disk 1 of the present invention can adopt the ROM (Read Only Memory) recording system, WO (Write Once) Recording system which permits recording and reproducing, or the RE (Re-Writable) recording system which permits recording, erasing and reproducing. [Example Structure of Optical Disk of ROM System] As illustrated in FIGS. 3(a) and 3(b), the optical disk 1 of the ROM system is arranged so as to record information as pits 8 formed in a recessed shape on the disk sheet 6, and by projecting the light beam to be focused on the pits 8, and detecting the reflected light, it is possible to reproduce information. Here, due to a difference in index of refraction between the disk sheet 6 and the adhesive layer 7, a part of the light beam 13 incident on the recording face 6a, the interface between the disk sheet 6 and the adhesive layer 7, is reflected on to the recording face 6a, and the resulting reflected light is detected by the photo-detector (not shown) in the optical pickup 16. As a result, information are reproduced by reading changes in amount of reflected light due to the presence or absence of the pits 8. For example, the optical reflectance R at the interface between the disk sheet 6 and the adhesive layer 7 is given as: R=((n1−n2)/(n1+n2))2, wherein n1 is the index of refraction of the disk sheet 6 and n2 is the index of refraction of the adhesive layer 7. For example, when a resin sheet made of polycarbonate resin with an index of refraction of 1.58 is adopted for the disk sheet 6, and acrylic ultraviolet curing resin containing fluorocarbon resin having an index of refraction n2 of 1.33 is adopted for the adhesive resin 7, the optical reflectance R at the interface between the disk sheet 6 and the adhesive layer 7 is 0.74%. For example, when projecting a laser beam having an intensity of 30 mW onto the recording face 6a on the light incident side, the intensity of the reflected light from the recording race 6a becomes 221 μW. In this case, however, a plurality of the interfaces are formed by the plurality of disk sheets 6, and the light beam intensity becomes lower when time the light beam passes through the interface. Namely, the more away from the light incident side, the lower is the intensity of the reflected light from the recording faced 6a, and the intensity of the reflected light is therefore subjected to changes by each recording face 6a. In response by adjusting the amplification factor etc., of the reproducing signal as detected by the photodetector of the optical pickup 16, it is possible to transmit the reproducing signal of a fixed level to the reproducing control circuit 17. In this example, explanations have been given through the case of adopting the polycarbonate resin and the acrylic ultraviolet curing resin for the disk sheet 6 and the adhesive layer 7 respectively. However, the materials of the disk sheet 6 and the adhesive layer 7 are not intended to be limited to the above example. For example, non-limited examples for the material of the disk sheet 6 includes: such polyethylene resin sheet as a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, or polypropylene resin sheet, and olefin resin sheet. According to the foregoing structure, a reproducing signal of sufficiently high intensity can be obtained by increasing the difference in index of refraction between the disk sheet 6 and the adhesive layer 7, which, in turn, increases the amount of reflected light from the recording face 6a at the interface between the disk sheet 6 and the adhesive layer 7. As illustrated in FIG. 3(b), according to the foregoing structure, by providing the reflective film 10 on each recording face 6a of the optical disk 1, it is possible to increase the amount of reflected light from the recording face 6a, and reduce the reproducing power. Here, it is desirable that the film thickness of the reflective film 10 (reflective index) be determined based on the number of recording faces 6a or the position of such recording faces 6a. Specifically, it is preferable that the reflective film 10 formed on the recording face 6a on the light beam incident side be formed thinner, and the recording face 6a laminated at that position be made more thick, and the film thickness of the reflective film 10 formed on each recording face 6a be controlled so as to realize an equal amount of reflected light from each recording face 6a. For the material of the reflective film 10, a material having a high reflectance with respect to a reproducing light beam is preferable for the following reason. That is, in the case of adopting the reflective film 10 of low reflectance, it is necessary to increase the film thickness of the reflective film 10 in order to increase the desired amount of reflected light. However, as the absorption increases with an increase in the thickness of the reflective film 10, the amount of light passed through the reflective light is reduced, which causes the reduced number of laminated layers of the recording face 6a. In view of the foregoing, for the reflective film 10, for example, a metal thin film made of, for example, Al, Au, Pt, Ti, Ag, etc., or an alloy of such metals is preferable. According to the foregoing optical disk 1 adopting the adopting the reflective film 10, the difference in index of refraction between the disk sheet 6 and the adhesive layer 7 cause the generation of reflected light not only from the recording face 6a having formed thereon the reflective film 10 but also from the interface between the back surface 6a of the disk sheet 6 and the adhesive layer 7. In this case, the reflected light beam from the interface reduces the amount of reflected light to be reproduces. It is therefore desirable that the index of refraction of the disk sheet 6 be equal to the index of refraction of the adhesive layer 7. [Example Structure of Optical Disk of WO System] As illustrated in FIGS. 4(a), the optical disk 1 of the WO system is arranged so as to form tracks 9 made up of lands 9a in a protruded shape and grooves 9b in a recessed shape, on the disk sheet 6. As illustrated in FIG. 4(b), a recording film 11 according to the WO system is formed on the track 9, a focused light beam is subjected to the tracking along the track 9. Then, information are recorded by projecting the pulse like light beam having a relatively low intensity, and information are reproduced by detecting the amount of reflected light of a focused light beam of relatively low intensity. The recording or reproducing of information may be performed with respect to either the lands 9a or the grooves 9b of the tracks or both the lands 9a and the grooves 9b. The structure of the optical disk 1 of the WO system is basically the same as the optical disk 1 of the ROM system. However, the optical disk 1 of the WO system differs from the optical disk 1 of the ROM system in that a recording film 11 (see FIG. 4(b)) is formed in replace of the reflective film 10 (see FIG. 3(b)). Further, according to the optical disk 1 of the WO system, with an increase in temperature by projecting a light beam to be focused on the recording film 11, the quality of the recording film 11 or the resin form in the vicinity of the recording film 11 changes, thereby recording information. For the recording layer 11, it is therefore necessary to absorb the light beam appropriately to raise the temperature to the desired temperature. As compared to the reflective film 10 adopted in the optical disk 1 of the ROM system, for the recording film 11 adopted is a material having a relatively low reflectance, and a high absorption coefficient. For the material of the recording film 11 of the optical disk 1 of the WO system, a phase change material containing as a main component at least two elements selected from the group consisting of Sb, Te, In, Ag and Ge may be adopted. With this structure, information are recorded by projecting a light beam pulse onto the amorphous recording film 11 made of the phase change material to partially change the phase to the polycrystalline state; on the other hand, information are reproduced by detecting changes in difference in index of refraction between the amorphous state and the polycrystalline state. For other recording film 11 of the optical disk 1 of the WO system, a metal film made of Ta, Si, etc., or an alloy including these metals as a main component may be adopted. When a light beam pulse is projected on to the metal film or the alloy film, the temperature is increase at the irradiated position, and the resin deforms in a vicinity of the irradiated position. Then, by detecting changes in reflectance due to the resin deformation, recorded information can be reproduced. [Example Structure of Optical Disk of RE System] The structure of the optical disk 1 of the RE system is the same as the optical disk 1 of the WO system. For the recording film 11 of the optical disk 1 of the RE system, a phase change material containing as a main component at least two elements selected from the group consisting of Sb, Te, In, Ag and Ge may be adopted as in the case of the optical disk 1 of the WO system. With this structure, information are recorded by projecting a light beam pulse onto the amorphous recording film 11 made of the phase change material to partially change the phase to the polycrystalline state; on the other hand, information are erased by projecting a light beam of relatively low intensity to change the phase from the polycrystalline state to the amorphous state. Here, it is preferable that the phase change material has an optimal composition so that the phase change occurs from the amorphous state to the polycrystalline state and from the polycrystalline state to the amorphous state. Incidentally, the recorded information can be reproduced by detecting the difference in reflectance between the polycrystalline state and from the polycrystalline state. [First Example Structure of Optical Disk] FIG. 5 shows the first example structure of the optical disk 1. In the first example structure, a plurality of disk sheets 6 that are laminated using an adhesive layer 7 are formed on the disk substrate 5. Here, one of the surfaces of each disk sheet 6 serves as a recording face 6a, and the other is a flat back surface 6b. These plurality of the disk sheets 6 are laminated by bonding together by means of the adhesive layers 7 in such a manner that the surface of the disk substrate 5 faces the recording face 6a of the disk sheet 6, and between two adjacent disk sheets 6, the recording face 6a of one of the disk sheets 6 faces the back surface 6b of the other disk sheet 6. On the recording face 6a, formed are pits 8 in a recessed shape (see FIG. 3(a)) or tracks 9 made up of lands 9a and grooves 9b (see FIG. 4(a)) on the recording face 6a. As described, on these pits 8 or tracks 9, formed is the reflective film 10 (see FIG. 3(b)), or the recording film (see FIG. 4(b)) according to the ROM, WO or RE system. In the ROM system, however, neither the reflective film 10 nor the recording film 11 is formed. The optical disk 1 in accordance with the first example structure is arranged so as to laminate the plurality of disk sheets 6, each having a recording face 6a. With this structure, as compared to the conventional optical disk, wherein an ultraviolet ray curing resin is hardened gradually on the substrate to form recording faces 6a (see FIG. 23), an applied force to be applied on the optical disk 1 as a show in the process of forming the recording faces 6a is extremely smaller, and the flatness of the optical disk 1 can be maintained with high precision. Furthermore, when laminating respective disk sheets 6, such problem that an applied force to be applied to the disk sheet 6 becomes small, and the thickness of each disk sheet 6 varies, or each disk sheet 6 is partially distorted is not liable to occur. It is therefore possible to control an interval between the recording faces 6a of adjacent disk sheets 6 with ease. The plurality of disk sheets 6 are laminated on the disk substrate 5 so that respective recording faces 6a are positioned in the same direction, and it is therefore possible to ensure an equal interval between the recording faces 6a of the adjacent disk sheets 6. Furthermore, the flat back surface 6b of the disk sheet 6 permits each recording face 6a to be formed with ease, and partial variations in the thickness of the disk sheets 6 generated in the process of forming the recording faces 6a can be suppressed. On of surfaces of the adhesive layer for use in bonding the adjacent disk sheets 6 together is a flat surface, and thus the process of bonding the disk sheets 6 can be carried out with ease. According to the foregoing optical disk 1, when recording or reproducing, the coma aberration or the spherical aberration of the light beam can be suppressed, thereby realizing desirable recording and reproducing characteristics. Other structure of laminating a plurality of disk sheets 6 on the disk substrate 5 than the foregoing structure may be adopted as will be explained below. [Second Example Structure of Optical Disk] FIG. 7 is a cross-sectional view of the second example structure of the optical disk 1. As illustrated in the FIG. 7, the optical disk 1 in accordance with the second example structure is arranged so as to form a protective layer 20 on the disk sheet 6 formed at position most apart from the disk substrate 5. Here, one of the surfaces of each disk sheet 6 serves as a recording face 6a, and the other is a flat back surface 6b. These disk sheets 6 are laminated by bonding together by means of the adhesive layers 7 in such a manner that the recording faces 6a of the disk sheets 6 face the disk substrate 5. In addition to the structure wherein the plurality of the disk sheets 6, one of the surfaces of each disk sheet 6 serves as a recording face 6a, and the other is a flat back surface 6b, are laminated in such a manner that the surface of the disk substrate 5 faces the recording face 6a of the disk sheet 6, and between two adjacent disk sheets 6, the recording face 6a of one of the disk sheets 6 faces the back surface 6b of the other disk sheet 6, the protective layer 20 is formed on the top most disk sheet 6 of the plurality of laminated disk sheets 6, at position most away from the disk substrate 5. Incidentally, in order to increase the recording capacity of the optical disk 1, it is preferable that the film thickness of each disk sheet 6 be made smaller so that the disk sheets 6 can be laminated as many as possible. Without the foregoing protective layer 20, when adopting a thin disk sheet 6 for the top most disk sheet 6, of the optical disk 1 (the disk sheet positioned most away from the disk substrate 5), a scratch generated due to an accidental drop of the optical disk 1, etc., would reach the recording face 6a of the disk sheet 6 at the top most position, which may result in the problem of losing information. Incidentally, with the structure adopting the thin film for the top most disk sheet 6 without the protective film 20, when projecting the light beam 13 to be focused on the top most disk sheet 6, a distance between the surface of the disk (back surface 7b of the top most disk sheet 6), and the recording face 6a of each disk sheet 6 (the recording face 6a of the top most disk sheet 6 and the recording face 6a of the disk sheet 6 laminated in a vicinity of the top most disk sheet 6, becomes smaller as compared to the case of adopting the protective layer 20 as shown in FIG. 7. With the foregoing structure without the protective layer 20, the spot diameter of the light beam 13 to be incident on the surface of the optical disk 1 becomes smaller, and an optical path of the light beam 13 would be disturbed due to even a fine scratch or fine dust particles adhered, which makes it difficult to record/reproduce information. In contrast, according to the optical disk 1 of the second example structure shown in FIG. 7, the protective film 20 is formed on the top most disk sheet 6, and a damage of the recording face 6a due to an accidental drop of the disk, etc., can be prevented. Additionally, the distance between the surface of the optical disk 1 (surface of the protective layer 20) and the recording face 6a of the disk sheet 6 can be made longer than that of the structure without the protective layer 20, and thus the diameter of the spot of the light beam 13 to be incident on the surface of the optical disk 1 (surface of the protective layer 20) can be made larger. As a result, when carrying out recording or reproducing operation by projecting the light beam 13 on to the top most disk sheet 6 (from the side of the disk sheet layer 4), adverse effects of the scratch or dust particles on the surface of the protective layer 20 onto the recording/reproducing characteristics can be suppressed. For the material of the protective layer 20, acrylic ultraviolet ray curing resin or epoxy series ultraviolet ray curing resin may be adopted, and the same material as the material of the adhesive layer 7 may be adopted. Incidentally, to suppress the reflectance of the light beam from the interface (back surface 6b) between the top most disk sheet 6 and the protective layer 20, it is desirable that the index of refraction of the protective layer 20 be equal to the index of refraction of the top most disk sheet 6. [Third Example Structure of Optical Disk] FIG. 8 is an enlarged cross-sectional view of the third example structure of the optical disk 1. The optical disk 1 shown in FIG. 8 adopts the structure wherein a protective sheet 22 in replace of the protective layer 20 adopted in the second example structure shown in FIG. 7. This protective sheet 22 is laminated by means of an adhesive agent layer 21. Namely, in addition to the structure wherein the plurality of the disk sheets 6, one of the surfaces of each disk sheet 6 serves as a recording face 6a, and the other is a flat back surface 6b, are laminated in such a manner that the surface of the disk substrate 5 faces the recording face 6a of the disk sheet 6, and between two adjacent disk sheets 6, the recording face 6a of one of the disk sheets 6 faces the back surface 6b of the other disk sheet 6, the protective sheet 22 is laminated on the top most disk sheet 6 of the plurality of laminated disk sheets 6 by means of the adhesive agent layer 21, at a position most away from the disk substrate 5. The foregoing third example structure offers the effects as achieved from the second example structure. That is, the recording face 6a can be prevented from being damaged by adopting the protective sheet 22, and when carrying out recording or reproducing operation, adverse effects of the scratch or dust particles on the surface of the optical disk 1 (surface of the protective sheet 22) onto the recording/reproducing characteristics can be suppressed. The protective film 20 adopted in the second example structure is formed by applying liquid ultraviolet ray curing resin by the spin coating method and further curing the ultraviolet ray with an application of an ultraviolet ray. Therefore, the thickness of the protective film 20 may differ between the inner circumference and the outer circumference of the disk. In contrast, according to the third example structure wherein the protective sheet 22 with an uniform film thickness is laminated onto the back surface 6b of the top most disk sheet 6 by means of the thin adhesive agent layer 21, variations in thickness of the surface portion of the optical disk (the protective sheet 22 and the adhesive agent layer 21 at portions corresponding to the protective layer 20 of the second example structure) can be suppressed. Variations in thickness of the layer cause an increase in the coma aberration or the spherical aberration of the focused light beam projected from the side of the disk sheet layer 4 when recording or reproducing. Therefore, it is effective to suppress variations in layer thickness by adopting the protective sheet 22 to maintain a desirable focused light beam, thereby realizing desirable recording and reproducing characteristics. [Fourth Example Structure of Optical Disk] FIG. 9 is an enlarged cross-sectional view of the fourth example structure of the optical disk 1. The optical disk 1 shown in FIG. 9 has the similar structure as the optical disk 1 in accordance with the first example structure (see FIG. 5), and differs from that of FIG. 5 in that the thickness of the top most disk sheet 6 is thicker than other disk sheets 6. Namely, in addition to the structure wherein the plurality of the disk sheets 6, one of the surfaces of each disk sheet 6 serves as a recording face 6a, and the other is a flat back surface 6b, are laminated in such a manner that the surface of the disk substrate 5 faces the recording face 6a of the disk sheet 6, and between two adjacent disk sheets 6, the recording face 6a of one of the disk sheets 6 faces the back surface 6b of the other disk sheet 6, the thickness of the top most disk sheet 6 laminated at a position most away from the disk substrate 6 is formed thicker than that of any other laminated disk sheets 6. According to the fourth example structure, by making the top most disk sheet 6 thicker, a scratch as generated due to an accidental drop of the disk, etc., can be prevented from reaching the recording face 6a (the recording face 6a of the top most disk sheet 6 in particular). Incidentally, the distance between the surface of the optical disk 1 (back surface 6b of the top most disk sheet 6) and the recording face 6a of the disk sheet 6 can be made larger than that in the first example structure (the top post disk sheet 6 is formed in the same thickness as other disk sheets 6), and the diameter of the spot of the light beam 13 (see FIG. 5) to be projected onto the surface of the disk 1 can be made larger. As a result, when carrying out the recording or reproducing operation, adverse effects of the scratch or dust particles on the surface of the optical disk 1 onto the recording/reproducing characteristics can be suppressed. The foregoing second example structure and the third example structure may be modified as shown in FIG. 10 and FIG. 11 wherein the disk sheets 6 are laminated in a reversed order so that the recording faces 6a and the back surfaces 6b face the disk substrate 5 in an opposite direction, and the foregoing effects as achieved from the structures of the second and third example structures can be achieved also from these modified example structures. In the modified example structure of FIG. 10, the protective layer 23 is the same as the protective layer 20 shown in FIG. 20, and in the modified example structure of FIG. 11, the protective sheet 25 is the same as the protective sheet 22 of FIG. 8. [Process of Forming Disk Sheet (Recording Face Forming Process)] The disk sheet 6 may be formed in a band shaped sheet by either the method i) or the method ii). i) A band shaped sheet material (sheet material) is depressed onto a stamper having a pattern of protrusions and recession corresponding to pits and tracks for the optical disk, by means of a roller or a holding member, to mechanically copy the pattern of protrusions and recessions, to be formed into the band shaped sheet; and ii) An ultraviolet ray curing resin layer formed in a uniform thickness between the band shaped sheet material and a stamper is hardened with an application of an ultraviolet ray, and the pattern of protrusions and recession corresponding to pits and tracks for the optical disk are copied, to be formed into the band shaped sheet. [First Method of Forming Disk Sheet] FIG. 12 is a cross-sectional view of the first disk sheet forming method. Firstly, a band-shaped sheet material 29m wound in a roll on the sheet roller 28a is conveyed to a spacing between the first rotation roller 35 provided with a stamper 30 on its surface and a second rotation roller 36 without having the pattern of protrusions and recessions formed on its surface. Here, the stamper 30 has the pattern of protrusions and recessions formed thereon, which correspond to the recording face 6a (pits and tracks). The first rotation roller 35 and the second rotation roller 36 are formed almost in the same shape, and are placed so as to face each other with an interval corresponding to the thickness of the band-shaped disk sheet 29. Next, the band-shaped sheet material 29m is depressed by the first rotation roller 35 an the second rotation roller 36, so as to mechanically copy the pattern of protrusions and recessions corresponding to the recording face 6a (pits and tracks) onto the band-shaped recording face 6a. The band-shaped disk sheet 29 is then transported from the sheet roller 28a with rotations of the first rotation roller 35 and the second rotation roller 36 to be wound up by the sheet roller 28b. The foregoing method is arranged so as to place the band-shaped sheet material 29m in the spacing between the first rotation roller 35 and the second rotation roller 36, and the band-shaped sheet material 29m is depressed by the first rotation roller 35 and the second rotation roller 36. These first and second rotation rollers 35 and 36 are formed in substantially the same shape, and are placed so as to face each other. Therefore, the respective depression forces are exerted from the above and the bottom onto the band-shaped sheet material 29m substantially symmetrically, and the band-shaped sheet material 29 having copied thereto the pattern is not liable to be curled. As a result, it is possible to copy the pattern of protrusions and recessions formed on the stamper 30 accurately onto the band-shaped sheet material 29m with accuracy. According to the foregoing method, the bending force is hardly exerted onto the plurality of band-shaped disk sheets 29 in the direction of bending them in the subsequent process (laminating the band-shaped disk sheet 29 shown in FIG. 20), even when adopting a large number of band-shaped disk sheets 29 to be laminated onto the disk substrate material 50. As a result, it is possible to manufacture optical disks 1 without the problem of much deformation even when adopting a fatigue disk substrate material 50. As a result, the disk substrate material 50 can be made thinner, which in turn makes the overall thickness of the optical disk 1 thinner. Incidentally, the foregoing first forming method may be arranged so as to heat the first rotation roller 35 and the second rotation roller 36 beforehand to a vicinity of a softening point so that the pattern can be copied under desirable conditions. [Second Method of Forming Disk Sheet] FIG. 13 is a cross-sectional view which shows the fourth method of forming the disk sheet 6. According to the first method of forming the disk sheet 6, a recording face 6a is formed by mechanically deforming the band-shaped sheet material 29m with an applied depression force. In contrast, according to the second method of forming the disk sheet 6, the recording face 6a made up of ultraviolet ray curing resin is formed on the band-shaped sheet material 29m. Firstly, a band-shaped sheet material 29m wound in a roll on a sheet roller 28a is conveyed towards a stamper 30 having formed thereon the pattern of protrusions and recessions corresponding to the recording face 6a (pits and tracks). Next, on the band-shaped disk sheet 29 or the stamper 30, liquid ultraviolet ray curing resin layer 37 is applied so as to form the ultraviolet ray curing resin layer 37 between the band-shaped sheet material 29m and the stamper 30. Next, the band-shaped disk sheet 29 is depressed by the rotation roller 34 onto the stamper 30 to make the thickness of the ultraviolet ray curing resin layer 37 uniform, and the band-shaped sheet material 29m and the stamper 30 are not moved in the direction of transporting the band-shaped sheet material 29m, and only the rotation roller 34 rotates to move in the direction of an arrow, while depressing the band-shaped sheet material 29m. After the rotation roller 34 is moved by rotating, an ultraviolet ray 28 is applied from the side of the band-shaped disk sheet 29 to cure the ultraviolet ray curing resin 37. As a result, it is possible to copy the pattern of protrusions and recessions onto the ultraviolet ray curing resin layer 37. Aster being cured, the ultraviolet ray curing resin 37 is removed from the stamper 39, thereby forming the band-shaped disk sheet 29 having the recording face 6a made of ultraviolet ray curing resin. The resulting band-shaped disk sheet 29 is then wound up onto the sheet roller 28b, and in the meantime, a new band-shaped sheet material 29m is conveyed towards the stamper 30, and the foregoing process is repeated. In the foregoing fourth method of forming a disk sheet, the ultraviolet ray 38 is applied from the side of the band-shaped sheet material 29m; however, in the case of adopting a transparent stamper 30, such as a glass stamper 30 having formed thereon a pattern of protrusions and recessions, it is possible to apply an ultraviolet ray from the side of the stamper 30. According to the foregoing method, it is possible to copy the pattern of pits and tracks formed on the stamper 3 onto the ultraviolet ray curing resin layer 37 in an efficient manner, thereby realizing the process of forming optical disks 1, which permits optical disks 1 to be manufactured with excellent productivity. As a result, a smaller size optical disk manufacturing device can be realized at low costs, which in turn reduces the cost of the optical disk 1. In the foregoing method, only the rotation roller 34 is moved by rotating in a direction of an arrow; however, it may be also arranged such that without moving the rotation roller 34 in the transport direction of the band-shaped sheet material 29m, the stamper 30 may be moved in the direction opposite to the direction of an arrow in the Figure by a predetermined distance from the initial position while depressing the band-shaped sheet material 29m. [Method of Forming Reflective Film and Recording Film] A read-only multi-layered Optical Disk of the ROM system may be manufactured in the following manner. That is, the band-shaped disk sheet 29, on which the recording face 6a having formed thereon the pattern of protrusions and recessions in the form of pits is formed, as manufactured in the foregoing method, is placed on the disk substrate 5, to be bonded together by means of an adhesive layer 7 having a different index of refraction from that of the band-shaped disk sheet 29, and the resulting laminated structure is processed in a form of a disk. It should be noted here that it is preferable that the reflective film 10 be formed on the recording face 6a (see FIG. 3(b)) to optimize the amount of reflected light from the recording face 6a also for the multi-layered optical disk of the ROM system. For the multi-layered optical disk of the WO system or the multi-layered optical disk of the RE system, it is necessary to form a recording film 11 (see FIG. 4(b)) on the recording face 6a made up of the pattern of protrusions and recessions in the form of tracks. FIG. 14 is a cross-sectional view showing the method of forming the reflective film 10 and the recording film 11 by the vacuum device. The vacuum device is made up of a first vacuum chamber 41, a film forming chamber 42a, and a second vacuum chamber 32. The film forming chamber 42a is positioned between the first vacuum chamber 41 and the second vacuum chamber 43. In the first vacuum chamber 41, provided is a sheet roller 28a on the outgoing side, and in the second vacuum chamber 43, provided is a sheet roller 28b on the winding side. At a boundary between the first vacuum chamber 41 and the film forming chamber 42a adjacently disposed and a boundary between the film forming chamber 42a and the second vacuum chamber 43, formed are vacuum valves 44 respectively. With this structure, when the sheet rollers 28a and 28b are to be exchanged, the vacuum valves 44 is closed, and the only the first vacuum chamber 41 and the second vacuum chamber 43 are set in the atmosphere pressure so that the required minimum space is set in the atmosphere pressure. In the film forming chamber 42a, provided is a sputtering chamber 49a having a ring-shaped shield 47a for limiting the film forming region, a support member 48a for supporting a band-shaped disk sheet 29 together with the ring-shaped shield 47a and a cooling table 46a. In the film forming chamber 42, the band-shaped disk sheet 29 is fixed by the ring-shaped shield 47 and the support member 48, to form a film. After forming the film, the band-shaped disk sheet 29 is transported by the sheet roller 28a on the outgoing side and the sheet roller 28b on the winding side. In the following, the method of forming the reflective film 10 and the recording film 11 will be explained. In the present embodiment, the film is formed by the roll to roll, and the band-shaped disk sheet 29 on which the recording face 6a made up of the pattern of protrusions and recessions in the form of pits or tracks is formed is wound on the outgoing side sheet roller 28a beforehand. First, in order to form the reflective film 10 or the recording film 11, first, the band-shaped disk sheet 29 is transported from the sheet roller 28a on the outgoing side to the film forming chamber 42a. In the film forming chamber 42a, the band-shaped disk sheet 29 is fixed as being sandwiched between the ring-shaped shield 47a and the support member 48a. In this state, the power is applied to the sputter target 45a fixed to the cooling table 46a, and the sputtering is carried out, thereby forming the reflective film 10 or the recording film 11 on the recording face 6a. Thereafter, the band-shaped disk sheet 29 is wound on the sheet roller 28b on the winding side. When forming the multi-layered optical disk of the ROM system, a metal thin film made of metal of high reflective index such as Al, Au, Pt, Ti, Ag, etc., or an alloy including such metal may be adopted for a sputtering target 45a. As a result, it is possible to optimize the reflective index of each recording layer 11. When forming the multi-layered optical disk of the WO system or the RE system, a film made of a phase change material containing as main components, two elements selected from the group consisting of Sb, Te, In, Ag, Ge, or a metal film of Ta, Si, etc., or an alloy film containing these metals as main components. In the foregoing process, a film is formed on the band-shaped disk sheet 29 after all the patterns has been formed. It is therefore not necessary to repeat the alternate process of forming the pattern (pits or tracks, for example) and of forming a film as required in the conventional method. In the conventional process, it is necessary to repeat the processes shown in FIGS. 25(b) and 25(c) many times, to form a plurality of first ultraviolet ray curing resin layers 103 and second reflective layers 106. Further, in the case of forming a multi-layered optical disk, after forming the first ultraviolet ray curing resin layers 103, it is necessary to form the second reflective film 106 using the vacuum evaporation device, or the sputtering device or other vacuum device, and take out the optical disk having formed thereon the second reflective layer 106 from the vacuum device, and then to repetitively form the ultraviolet ray curing resin layer 103 and the reflective layer 106. [Fifth Example Structure of Optical Disk] For example, as illustrated in FIG. 16 of a perspective cross-sectional view of the optical disk 1, the optical disk 1 of the present invention includes a disk sheet layer 4 formed on the disk substrate 5. Further, as illustrated in FIG. 17 which is a cross-section of FIG. 16 enlarged in the thickness direction, the disk sheet layer 4 is formed by laminating a plurality of disk sheets 6 being bonded using the adhesive agent 7. On the recording face, i.e., one of the surfaces of each disk sheet 6, information is recorded in the pattern of protrusions and recessions in the spiral or centric form. Incidentally, the disk substrate 5 may include the inner circumferential hole 2 for centering when rotation driving the optical disk 1. Here, the inner diameter 50 of the disk sheet layer 4 is set larger than the inner diameter 50′ of the disk substrate 5, and the outer diameter 51 is set smaller than the outer diameter 51′ of the disk substrate. In the following, explanations will be given through the case where both the inner diameter 50 and the outer diameter 51 satisfy the above conditions. However, the effect of the present invention can be achieved as long as either the inner diameter 50 or the outer diameter 51 satisfies the above conditions. By adopting the foregoing optical disk 1, and the optical disk reproducing device or the optical disk recording device, it is possible to reproduce or record information on and from the optical disk 1 including the plurality of recording faces 6a, thereby realizing a large volume optical disk device. As illustrated in FIG. 16, the optical disk 1 of the present invention is arranged such that the inner diameter 50 of the disk sheet layer 4 is larger than the inner diameter 50′ of the disk substrate 5. Therefore, as illustrated in FIG. 6, when caching the optical disk 1 to the spindle 15, the disk substrate 5 contacts the spindle 15, and the disk sheet layer 4 does not contact the spindle 15 or any other members. For the optical disk 1 of the present invention, it is preferable that the disk sheet 6 be set in the optical disk recording device or reproducing device without contact in view of the following problem. That is, the disk sheet layer 4 at the inner circumference of the optical disk is separated from the disk substrate 5, or from the adjacent disk sheet 6. As described, according to the optical disk 1 of the present invention wherein the inner diameter 50 of the disk sheet layer 4 is set larger than the outer diameter 51′ of the disk substrate 5, the problem of the disk sheet layer 4 at the central hole of the optical disk 1 being separated from the disk substrate 5 or from the adjacent disk sheet 6 can be suppressed. For example, for the handling (evaluating) the optical disk 1, when inserting a jig in the central hole of the optical disk 1 or fixing/holding the optical disk 1, by setting the inner diameter 50 of the disk sheet layer 4 be equal to the inner diameter 51′ of the optical disk 5, the disk sheet layer 4 can be maintained at a fixed position by the jig together with the disk substrate 5. In this case, as the jig contacts the central hole of the disk sheet layer 4, it is more likely that the disk sheet layer 4 be separated from the disk substrate 5 or the disk sheet 6 be separated from the adjacent disk sheet 6. In contrast, according to the structure wherein the inner diameter 50 of the disk sheet layer 4 is larger than the inner diameter 51′ of the disk substrate 5, the jig for handling the optical disk 1 holds only the central hole of the disk substrate 5 at a fixed position, and the jig does not contact the central hole of the disk sheet layer 5. Therefore, the disk sheet layer 4 can be separated from the disk substrate 5 and from the adjacent disk sheet 6, thereby providing a highly reliable optical disk 1. When setting the optical disk 1 in the recording/reproducing device, the central hole of the optical disk 1 is held with respect to the rotation spindle 15 at a fixed position. Therefore, by setting the inner diameter 50 of the disk sheet layer 4 larger than the inner diameter 51′ of the disk substrate 5, the problem of the disk sheet layer 4 at the central hole of the optical disk 1 being separated from the disk substrate 5 or from the adjacent disk sheet 6 can be suppressed, thereby providing a highly reliable optical disk 1. The optical disk 1 of the present invention is arranged such that the outer diameter 51 of the disk sheet layer 4 is set smaller than the outer diameter 51′ of the disk substrate 5. To set or take out the optical disk 1 in or from the optical disk reproducing device or recording device shown in FIG. 6, when handling the circumferential edge of the optical disk 1, the outer circumferential edge of the disk substrate 5 is handled, and the disk sheet layer 4 does not contact any member (The handling of the disk sheet is never handled). In the optical disk 1 of the present invention, it is preferable that the handling of the disk sheet 6 be not performed when the optical disk 1 is set in or take out of the optical disk reproducing or recording device because such problem of the disk sheet layer 4 at the outer circumference of the optical disk being separated from the disk substrate or from the adjacent disk sheet 6, or the disk sheet 6 being separated from the adjacent optical sheet 6 can be suppressed. As described, the optical disk 1 of the present invention is arranged such that the outer diameter 51 of the disk sheet layer 4 is set smaller than the outer diameter 51′ of the disk substrate 5, and such problem of the disk sheet layer 4 at the outer circumference of the optical disk 1 being separated from the disk substrate or from the adjacent disk sheet 6, or the disk sheet 6 being separated from the adjacent optical sheet 6 can be suppressed, thereby providing a highly reliable optical disk 1. The optical disk 1 of the present invention is arranged such that the outer diameter 51 of the disk sheet layer 4 is set smaller than the outer diameter 51′ of the disk substrate 5. To set or take out the optical disk 1 in or from the optical disk reproducing device or recording device shown in FIG. 6, when handling the circumferential edge of the optical disk 1, the outer circumferential edge of the disk substrate 5 is handled, and the disk sheet layer 4 does not contact any member (The handling of the disk sheet is never handled). In the optical disk 1 of the present invention, it is preferable that the handling of the disk sheet 6 be not performed when the optical disk 1 is set in or take out of the optical disk reproducing or recording device because such problem of the disk sheet layer 4 at the outer circumference of the optical disk being separated from the disk substrate or from the adjacent disk sheet 6, or the disk sheet 6 being separated from the adjacent optical sheet 6 can be suppressed. For example, for the handling of the optical disk 1, when fixing the outer circumference of the optical disk 1 with a jig, by setting the outer diameter 51 of the disk sheet layer 4 be equal to the outer diameter 51′ of the optical disk 5, the disk sheet layer 4 can be maintained at a fixed position by the jig together with the disk substrate 5. In this case, as the jig contacts the disk sheet layer 4, it is more likely that the disk sheet layer 4 be separated from the disk substrate 5 or the disk sheet 6 be separated from the adjacent disk sheet 6. In contrast, with the structure wherein the outer diameter 51 of the disk sheet layer 4 is smaller than the outer diameter 51′ of the disk substrate 5, the jig contacts only the outer circumference of the disk substrate 5, and does not contact the outer circumference of the disk sheet layer 4. As a result, such problems that the disk sheet layer 4 is separated from the disk substrate 5, or the disk sheet 6 separated from the adjacent disk sheet 6, thereby providing a highly reliable optical disk 1. [Sixth Example Structure of Optical Disk] According to the optical disk 1 shown in FIG. 16 and FIG. 17, explanations have been given through the case where inner diameters or outer diameters of respective disk sheets 6 laminated on the disk substrate 5 are set all equal. With this structure, however, the level difference at the inner circumferential ends or outer circumferential ends between the disk substrate 5 and the disk sheets 6 laminated on the disk substrate 5. Therefore, in such event that the optical disk is accidentally dropped, and a collision of unspecified substances occurs at the vertical level difference, the unspecified substances would be caught by the vertical level difference, which would cause a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6. FIGS. 18 and 19 respectively show a perspective cross-sectional view and an enlarged cross-sectional view of the optical disk which permits the disk sheet layer 4 to be separated from the disk substrate 5 or from the adjacent disk sheet 6 can be suppressed. As illustrated in FIG. 19, the plurality of disk sheets 6 of the disk sheet layer 4 are laminated in such a manner that the further from the disk substrate 5 in a laminating direction, the larger is the inner diameter of the disk sheet 6. With this structure, a vertical level difference as generated in the earlier explained examples would not occur, and the inner circumferential end of the disk sheet layer 4 forms a smooth slope. With this structure, the foregoing problem of the unspecified substances being caught which in turn causes the problem of a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6 can be suppressed. As a result, a highly reliable optical disk can be realized. Specifically, with the structure wherein the inner diameters of the disk layers 6 of the disk sheet layer 4 are set equal irrespectively of the distance from the disk substrate 5, the vertical level difference at the inner circumferential ends of the disk sheets 6 would be large. For example, when ten disk sheets 6, each having a thickness of 39 μm are laminated, and an adhesive agent layer is formed between adjacent disk sheets 6 in a thickness of 1 μm, the vertical level difference at the inner circumferential ends would be 400 μm. Therefore, in such event that the optical disk is accidentally dropped, and a collision of unspecified substances occurs at the vertical level difference, which would cause a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6. In contrast, according to the structure of the present invention wherein the plurality of disk sheets 6 of the disk sheet layer 4 are laminated in such a manner that the further from the disk substrate 5 in a laminating direction, the larger is the diameter of the disk sheet 6, a vertical level difference as generated in the earlier explained examples would not occur, and the inner circumferential end of the disk sheet layer 4 forms a smooth slope. With this structure, the foregoing problem of the unspecified substances being caught which in turn causes the problem of a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6 can be suppressed. As a result, a highly reliable optical disk can be realized. As illustrated in FIG. 19, the optical disk 1 in accordance with the present example is also arranged such that the plurality of disk sheets 6 of the disk sheet layer 4 are laminated in such a manner that the further from the disk substrate 5 in a laminating direction, the smaller is the outer diameter of the disk sheet 6. As illustrated in FIG. 19, the plurality of disk sheets 6 of the disk sheet layer 4 are laminated in such a manner that the further from the disk substrate 5 in a laminating direction, the larger is the inner diameter of the disk sheet 6. With this structure, a vertical level difference as generated in the earlier explained examples would not occur, and the outer circumferential end of the disk sheet layer 4 forms a smooth slope. With this structure, the foregoing problem of the unspecified substances being caught which in turn causes the problem of a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6 can be suppressed. As a result, a highly reliable optical disk can be realized. In the case where the outer diameter of the disk sheet layer 4 is set equal irrespectively of the distance from the disk substrate 5, the vertical level difference at the outer circumferential ends of the disk sheets 6 would be large. Therefore, in such event that the optical disk 1 is accidentally dropped, and a collision of unspecified substances occurs at the vertical level difference, the unspecified substances would be caught by the vertical level difference, which would cause a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6. In contrast, according to the structure of the present invention wherein the plurality of disk sheets 6 of the disk sheet layer 4 are laminated in such a manner that the further from the disk substrate 5 in a laminating direction, the larger is the diameter of the disk sheet 6, a vertical level difference as generated in the earlier explained examples would not occur, and the inner circumferential end of the disk sheet layer 4 forms a smooth slope. With this structure, the foregoing problem of the unspecified substances being caught which in turn causes the problem of a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6 can be suppressed. As a result, a highly reliable optical disk can be realized. FIG. 20 shows the structure of the optical disk 1 shown in FIG. 16 wherein a protective film 52 is formed on the surface of the optical disk 1 so as to cover the inner circumferential ends or the outer circumferential ends in the disk diameter of the disk sheet layer 4. FIG. 21 shows the structure of the optical disk 1 shown in FIG. 18 wherein a protective film 52 is formed on the surface of the optical disk 1 so as to cover the inner circumferential ends or the outer circumferential ends in the disk diameter of the disk sheet layer 4. The protective film 52 of this example is formed so as to cover both the inner circumferential ends and the outer circumferential ends of the disk sheets of the disk sheet layer; however, the protective film 52 is not necessarily be formed so as to cover both as long as it covers at least the inner circumferential ends or the outer circumferential ends. According to the foregoing structure, at least the inner circumferential ends or the outer circumferential ends of the disk sheet layer 4 are completely covered with the protective film 52. Therefore, in such event that the optical disk is accidentally dropped, and a collision of unspecified substances occurs at the inner circumferential end or the outer circumferential end of the disk sheet layer 4, the unspecified substances would hit the protective film 52, and thus would not cause a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6. As a result, the problem of the unspecified substances being caught which in turn causes the problem of a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6 can be surely prevented, thereby realizing a more highly reliable optical disk 1. The foregoing protective film 52 may be formed so as to cover the inner circumferential end or the outer circumferential end of the disk sheet layer 4 when forming the protective layer 20 shown in FIG. 7. The protectively layer 52 may be formed so as to cover the inner circumferential end or the outer circumferential end of the disk sheet layer 4 when forming the protective layer 22 shown in FIG. 8. Namely, the protective layer 20 shown in FIG. 7 or the protective sheet 22 shown in FIG. 8 may be formed so as to cover not only the top most surface of the disk sheet 6 but also the inner circumferential ends or the outer circumferential ends. Next, FIG. 22 is a cross-sectional view of a multi-layered optical disk wherein the thickness of the inner circumferential region 53 (second region) and the outer circumferential region 54 (second region) of the disk substrate 5 is formed thicker than the region where the disk sheet layer 4 is laminated (first region). Here, the inner circumferential region 53 is defined to be a region in the inside of the predetermined first radius on the disk substrate 5, and the outer circumferential region 54 is defined to be a region in the outside of the second radius which is set larger than the first radius on the disk substrate 5. The disk sheet layer 4 is formed in the region outside the inner circumferential region 53 and the outer circumferential region 54, i.e., in the outside of the first radius and in the inside of the second radius. As illustrated in FIG. 22, the disk sheet layer 4 is formed in the disk substrate 5, so as to be protective by the inner circumferential region 53 and the outer circumferential region 54 of the disk substrate 5, which are formed thicker. Incidentally, the effect of protecting the disk sheet layer 4 can be achieved also from the structure wherein only the inner circumferential region in the inside of the predetermined radius of the disk substrate 5 is formed thicker or only the outer circumferential region in the outside of the predetermined radius of the disk substrate 5 is formed thicker. As described, the disk sheet layer 6 can be prevented from being separated from the disk substrate 5 or from the adjacent disk sheet layer 6, and it is therefore possible to still increase the mechanical strength of the optical disk. For example, when fifteen disk sheets 6, each having a thickness of 39 μm are laminated, and an adhesive agent layer is formed between adjacent disk sheets 6 in a thickness of 1 μm, an overall thickness of the disk sheets 6 to be laminated on the disk substrate 5 would be 600 μm. In consideration of the convertibility with a conventional optical disk (thickness of 1.2 mm), it is desirable that the thickness of the disk substrate 5 be set to 600 μm. However, a reduction in thickness of the optical disk 5 would reduce the mechanical strength of the optical disk. Incidentally, for example, when the outer circumferential end of the disk substrate 5 having a thickness of 600 μm has an impact as being dropped, for example, the outer circumferential end of the disk substrate 5 would be damaged with ease. Incidentally, by fixing and holding the inner circumferential end (central hole) of the disk substrate 5, by repeating the installation of the optical disk in a recording/reproducing device, the inner circumferential end of the disk substrate 5 would be gradually deformed or damaged. Therefore, in such event that the optical disk is accidentally dropped, and a collision of unspecified substances occurs at the vertical level difference, the unspecified substances would be caught by the vertical level difference, which would cause a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6. In contrast, according to the structure of the present invention wherein the plurality of disk sheets 6 of the disk sheet layer 4 are laminated in such a manner that the further from the disk substrate 5 in a laminating direction, the larger is the diameter of the disk sheet 6, a vertical level difference as generated in the earlier explained examples would not occur, and the inner circumferential end of the disk sheet layer 4 forms a smooth slope. With this structure, the foregoing problem of the unspecified substances being caught which in turn causes the problem of a separation of the disk sheet layer 4 from the disk substrate 5, and from the adjacent disk sheet 6 can be suppressed. As a result, a highly reliable optical disk can be realized. By setting at least one of the inner circumferential region 53, the outer circumferential region 54 thicker than the thickness of the region where the disk sheets 6 (disk sheet layer 4) are formed, it is possible to increase the mechanical strength of at least one of the inner circumferential region 53 and the outer circumferential region 54, which is/are formed thicker, thereby suppressing a possible damage on the disk substrate 5 as being accidentally dropped, or repetitively installed in a recording/reproducing device. By forming the inner circumferential region 53 and the outer circumferential region 54 of the disk substrate 5 thicker, it is possible to suppress a damage on the disk substrate 5 when being accidentally dropped or repetitively installed in a recording/reproducing device. Next, FIG. 23 shows a cross-sectional view of a multi-layered optical disk having the structure in which the adhesive agent is filled in the spacing 55 between the inner circumferential region 53 and the disk sheet layer 4, and in the spacing 56 between the outer circumferential region 54 and the disk sheet layer 4. In the multi-layered optical disk shown in FIG. 23, a bonding agent is filled in the spacing 55 with the inner circumferential region 53 and in the spacing 56 with the outer circumferential region 54, the respective sides of the disk sheet layer 4 are completely fixed to the disk substrate 5. Therefore, as compared to the multi-layered optical disk shown in FIG. 22, the mechanical strength becomes still higher, and the separation of the disk sheet layer 4 from the disk substrate 5 and from an adjacent disk sheet 6 can be still suppressed. By setting at least one of the inner circumferential region 53, the outer circumferential region 54 thicker than the thickness of the region where the disk sheets 6 (disk sheet layer 4) are formed, it is possible to increase the mechanical strength of at least one of the inner circumferential region 53 and the outer circumferential region 54, which is/are formed thicker. Further, by filling with the bonding agent, the spacing 55 between the inner circumferential region 53 and the disk sheet layer 4, or the spacing 56 between the outer circumferential region 54 and the disk sheet layer 4, or both in the spacing 55 and the spacing 56, it is possible to make the optical disk thinner, thereby realizing an optical disk of a mechanical strength. By forming the inner circumferential region 53 and the outer circumferential region 54 of the disk substrate 5 thicker, it is possible to suppress a damage on the disk substrate 5 when being accidentally dropped or repetitively installed in a recording/reproducing device. Next, FIG. 23 shows a cross-sectional view of a multi-layered optical disk having the structure in which the adhesive agent is filled in the spacing 55 between the inner circumferential region 53 and the disk sheet layer 4, and in the spacing 56 between the outer circumferential region 54 and the disk sheet layer 4. Further, the respective ends of the disk sheet layer 4 are completely fixed to the disk substrate 5 by the bonding agent thus filled, and it is therefore possible to further suppress the separation of the disk sheet layer 4 from the disk substrate 5 and from the adjacent disk sheet 6. According to the foregoing optical disk, the disk sheet layer 4 is formed on the disk substrate 5 in such a manner that the recording face 6a and the back surface 6b of the adjacent disk sheets 6 face each other, to have a uniform interval between the adjacent recording faces 6a. Therefore, for an optical disk device for recording or reproducing on or from the foregoing optical disk, it is possible to project a light beam with small coma aberration, spherical aberration, etc., to be focused on the recording face, thereby realizing an optical disk recording device or reproducing device which permits desirable recording/reproducing characteristics to be realized. Furthermore, according to the foregoing optical disk, the interval between recording faces 6a of the adjacent disk sheets 6 can be made uniform, and when a focused light beam on one recording face 6a is moved to another recording face 6b, it is possible to accurately predict the distance to the target recording face 6a. Further, it is possible to make an interlayer access jump based on the distance to the target recording face 6a as predicted. Furthermore, by increasing the mechanical strength of the optical disk, the side-runout of the optical disk when recording/reproducing can be suppressed, thereby providing an optical recording/reproducing device which realizes desirable recording/reproducing characteristics. EMBODIMENTS First Embodiments In the present embodiment, the method of manufacturing an optical disk of quadri-layered structure of the ROM system will be explained. According to the method of forming a disk sheet shown in FIG. 12, a band-shaped disk sheet 29 having a recording face 6a with bits 8 in recessed form will be explained. For the band-shaped disk sheet 29, a polycarbonate film with a thickness of around 30 μm is formed. In the method of forming the disk sheet shown in FIG. 12, the band-shaped disk sheet 29 is provided between the first rotation roller 36 and the second rotation roller 35 with the stamper 30, and as being depressed with a pressure of 6 MPa, a bit pattern can be copied to the surface of the stamper 30. Here, the bit pattern is copied in the state where the first rotation roller 36 and the second rotation roller 35 with the stamper 30 are heated to 130° C. beforehand. With respect to eight kinds of stampers 30 with the bit pattern in which different kinds of information are recorded, four kinds of band-shaped disk sheets are formed corresponding to the respective stampers 30. Next, according to the film forming method shown in FIG. 14, a reflective film 10 made of AlTi alloy is formed on the recording face of each of the four kinds of band shaped disk sheets 29. The film thickness of the reflective film of each band-shaped disk sheet 29 is determined so as to obtain substantially equal intensity of the light reflected from each layer. Namely, the film thickness of each reflective film is adjusted so as to have the indexes of reflectance of the layers of 15%, 24%, 42% and 94% respectively in this order from the light incident side. With this structure, when laminating the band-shaped disk sheet 29, the intensity of the light reflected from each layer can be made substantially equal, i.e., 15%. Next, on the disk substrate 5 in 1.0 mm thickness made up of polycarbonate resin, four kinds of band-shaped disk sheets 29 are laminated using the adhesive agent layer 7 made of acrylic ultraviolet ray curing resin. The disk sheets 29 thus laminated are then cut in a disk shape. Here, the disk sheets 6 are laminated so that the recording face 6a of each disk sheet 6 faces the side of the disk substrate 5 (see FIG. 5). Here, the thickness of the adhesive agent layer 7 made of ultraviolet ray curing resin is set to 1 μm. The quadri-layered optical disk thus formed in the foregoing method is set in the optical disk reproducing device shown in FIG. 6. Then, the light beam is projected so as to be focused on each recording face 6a to reproduce information recorded in the bit pattern. As a result, the bit error rate (BER: Bit Error Rate) of 1×10−4 is obtained at the recording face 6a on the light incident side, and the bit error rate (BER: Bit Error Rate) of 1×10−5 to 2×10−5 can be obtained at each of other recording faces 6a. Namely, the bit error rate in the practical level can be obtained in any of the recording faces 6a of these four disk sheets 6. Second Embodiment In the present embodiment, a protective layer 20 made of ultraviolet ray curing resin is formed on an optical disk in the quadri-layer structure of the ROM system (see FIG. 7). Specifically, after spin-coating the surface of the upper most disk sheet 6 with the acrylic series ultraviolet ray curing resin, an ultraviolet ray is projected, to form the protective layer 20 made of ultraviolet ray curing resin layer formed in the thickness of 30 μm. With respect to the foregoing quadri-layered optical disk having formed thereon the protective layer 20, information is reproduced in the same manner as the first embodiment. As a result, it can be confirmed that all the recording faces 6a show the bit error rate (BER: Bit Error Rate) in a range of 4×10−5 to 7×10−5. The reason why desirable effect can be achieved from the structure of the present invention is that the light beam is incident on the surface of the protective layer 20, and the light beam spot on the light incident surface becomes enlarged, whereby an occurrence of an error due to the scratch or dust particles on the light incident surface can be suppressed. Third Embodiment In the present embodiment, a protective layer 22 made of polycarbonate resin is formed on the optical disk of the quadri-layer structure of the ROM system (see FIG. 7) in accordance with the first embodiment. Specifically, on the surface of the upper most disk sheet 6, using the adhesive agent layer 21 made of acrylic series ultraviolet ray curing resin, the protective layer 22 made of polycarbonate resin is formed in the thickness of 30 μm. With respect to the foregoing quadri-layered optical disk having formed thereon the protective layer 20, information is reproduced in the same manner as the first embodiment. As a result, it can be confirmed that all the recording faces 6a show the bit error rate (BER: Bit Error Rate) in a range of 1×10−5 to 2×10−5. The reason why desirable effect can be achieved from the structure of the present embodiment is that the light beam is incident on the surface of the protective layer 22, and the light beam spot on the light incident surface becomes enlarged, whereby an occurrence of an error due to the scratch or dust particles on the light incident surface can be suppressed. In the second embodiment, the BER of the recording face 6a on the side of the light incident surface is improved; however, the BER at other recording faces 6a are deteriorated. This is because due to variations in the shape of the focused beam spot, an occurrence of the error is increased. In contrast, according to the present embodiment (third embodiment), the thickness of the protective sheet 22 becomes uniform, which suppresses an occurrence of the focused beam spot, and a desirable BER can be realized at all the recording faces 6a. Fourth Embodiment In the present embodiment, adopted is the optical disk of the quadri-layer structure of the ROM system having the same structure as the first embodiment, except that the upper most disk sheet 6 is made thicker (see FIG. 9). Specifically, only the upper most disk sheet 6 is formed in the thickness of 60 μm, and other disk sheets 6 are formed in the thickness of 30 μm. With respect to the foregoing quadri-layered optical disk having formed thereon the protective layer 20, information is reproduced in the same manner as the first embodiment. As a result, it can be confirmed that all the recording faces 6a show the bit error rate (BER: Bit Error Rate) in a range of 1×10−5 to 2×10−5. The reason why desirable effect can be achieved from the structure of the present embodiment is that by adopting the thicker disk sheet 6 for the upper most disk sheet 6, as compared to the case where the disk sheet 6 is selected to be in the same thickness as other disk sheets 6, the light beam spot on the light incident surface can be made larger, whereby an occurrence of an error due to the scratch or dust particles on the light incident surface can be suppressed. According to the present embodiment, the thickness of the protective sheet 22 is made uniform, thereby achieving the effects of suppressing an occurrence of the focused beam spot, and achieving a desirable BER at all the recording faces 6a. Fifth Embodiment In the present embodiment, adopted is an optical disk in the quadri-layer structure of the ROM system (see FIG. 10) having the same structure as that of the second embodiment except that disk sheets 6 are laminated in the versed order (the back surface 6b of each disk sheet 6 is positioned on the side of the disk substrate 5). As in the case of the second embodiment, the protective layer 23 made of ultraviolet ray curing resin layer is formed on the upper most disk sheet 6 so as to cover its recording face 6a. The optical disk in accordance with the present embodiment is further arranged to form the protective layer 23 thicker, specifically, in the thickness of 60 μm to ensure a large interval between the light incident surface and the recording face 6a of the upper most disk sheet 6, and to suppress an occurrence of an error due to the scratch or dust particles on the light incident surface. With respect to the foregoing quadri-layered optical disk, information is reproduced in the same manner as the second embodiment. As a result, it can be confirmed that all the recording faces 6a show the bit error rate (BER: Bit Error Rate) in a range of 4×10−5 to 7×10−5. Sixth Embodiment In the present embodiment, adopted is an optical disk in the quadri-layer structure of the ROM system (see FIG. 11) having the same structure as that of the third embodiment except that disk sheets 6 are laminated in the versed order (the back surface 6b of each disk sheet 6 is positioned on the side of the disk substrate 5). As in the case of the third embodiment, a protective sheet 25 made of polycarbonate resin is formed on the upper most disk sheet 6 so as to cover its recording face 6a using the adhesive agent 24 made of acrylic series ultraviolet ray curing resin. Here, the adhesive agent layer 24 is formed in 1 μm to suppress variations in its thickness, and the protective sheet 25 is formed in 60 μm to ensure a large interval between the light incident surface and the recording face 6a of the upper most disk sheet 6, and to suppress an occurrence of an error due to the scratch or dust particles on the light incident surface. With respect to the foregoing quadri-layered optical disk, information is reproduced in the same manner as the third embodiment. As a result, it can be confirmed that all the recording faces 6a show the bit error rate (BER: Bit Error Rate) in a range of 1×10−5 to 2×10−5 as in the case of the third embodiment. Seventh Embodiment In the present embodiment, formed is an optical disk 1 shown in FIG. 16 and FIG. 17. The disk sheet 6 includes a disk substrate made of polycarbonate film in the thickness of 30 μm and an ultraviolet ray curing resin layer formed thereon in a thickness of 3 μm, and on the surface of the ultraviolet ray curing resin, pits 8 with a depth of 20 nm and width 0.3 μm are formed in a spiral form at pitches of 0.5 μm. Here, using four kinds of original plates with pit pattern in which different kinds of information are recorded, four kinds of sheets 6 corresponding to the original plates are formed. Next, for each of these four kinds of disk sheets 7, a reflective film made of AlTi alloy is formed on the recording face 6a, and after forming the disk sheet 6 in a shape of a disk, four kinds of disk sheets 6 are laminated using the adhesive agent 7 made of acrylic series ultraviolet ray curing resin on the disk substrate made of polycarbonate resin in the thickness of 1.0 mm. Here, the disk substrate 5 is formed to have an inner diameter 50′ of 15 mmφ, and an outer diameter of 51′ of 120 mmφ, and the disk sheets 6 are all have the inner diameter 50 of 25 mm and an outer diameter 51 of 115 mmφ. The respective disk sheets 6 are formed as shown in FIG. 5, i.e., the recording face 6a of each disk sheet 6 is formed on the side of the disk substrate 5, thereby forming the quadri-layered optical disk of the ROM system in which four disk sheets 6 are formed on the disk substrate 5. The quadri-layered optical disk formed in the foregoing method is set in the optical disk reproducing device shown in FIG. 6, and the light beam 13 is projected from the side of the disk sheet 6, so that the light beam 13 is focused onto the recording face 6a to reproduce information recorded in the bit pattern of protrusions and recessions. As a result, the recording face 6a on the light incident side shows the bit error rate of 1.5×10−4 , and the bit error rate (BER: Bit Error Rate) of 1×10−5 to 2×10−5 can be obtained at each of other recording faces 6a. Namely, the bit error rate in the practical level can be obtained in any of the recording faces 6a of these four disk sheets 6. Incidentally, the quadri-layered optical disk in which the inner diameter is set equal to the outer diameter of the disk substrate 5 and the disk sheet layer 6 is formed as a comparative example of the present embodiment, and installation and removal of the quadri-layered optical disk in accordance with the present embodiment and the quadri-layered optical disk of the comparative example are repeated in and from a CD disk case available in the market. Here, the CD disk case has inner circumferential protrusion corresponding to the central hole 2 of the disk substrate 2, so as to be mechanically depressed and supported. After repeating the installation and removal of the optical disk 100 times, the respective states of the disk substrate 5 and the disk sheet layer 4 and adjacent disk sheets 6 are checked. As a result, as to the quadri-layered optical disk in accordance with the seventh embodiment, the disk sheet layer 4 can be prevented from being separated from the disk substrate 5, or from the adjacent disk sheet 6. In contrast, as to the quadri-layered optical disk in accordance with the comparative example, the disk sheet layer 4 is separated both from the disk substrate 5 and from the adjacent disk sheet 6 at both inner circumferential end and the outer circumferential end. For the comparative example, the separation of the disk sheet layer 4 occurs at the inner circumferential end because the inner circumferential protrusion of the CD disk case contacts the disk substrate 5 and the disk sheets 6. On the other hand, the separation of the disk sheet layer occurs at the outer circumferential end due to the handling when installing and removing the comparative optical disk. On the other hand, in the seventh embodiment, the disk sheets 6 can be prevented from contacting other member when being installed and removed, which in turn prevents the disk sheet 6 from being separated from the disk substrate 5. Eighth Embodiment A multi-layered optical disk shown in FIG. 18 and FIG. 19 is formed as an optical disk in accordance with the present embodiment. In the seventh embodiment, the disk sheets 6 are all have the inner diameter 50 of 25 mm and an outer diameter 51 of 115 mmφ. In the present embodiment, however, the disk sheet 6 formed next to the disk substrate 5 is set so as to have the inner diameters 50 of 25 mmφ, and an outer diameter 51 of 115 mmφ, and respective other disk sheets 6 formed on that disk sheet 6 are selected to have inner diameters of 24.5 mmφ, 25.0 mmφ, and 25.5 mmφ, in this order, and the outer diameters of 115.5 mmφ, 115.0 mmφ, and 114.5 mmφ in this order. Namely, other disk sheets are formed so as to have a larger inner diameter than the adjacent disk sheet 6 by 0.5 mm, and a smaller outer diameter than the adjacent disk sheet 6 by 0.5 mm. Other than the size, the quadri-layered optical disk in accordance with the present embodiment is the same as that of the seventh embodiment. Here, the quadri-optical disk in accordance with the eighth embodiment is arranged such that the further is the disk sheet 6 from the disk substrate, the larger is the inner diameter, and the smaller is the outer diameter. Therefore, as compared to the seventh embodiment, the level different at the inner and outer circumferential ends (edges) of the disk sheet layer 4 can be made smoother, and the edges can be prevented from being caught. As a result, the separation of the disk sheet 6 can be suppressed, thereby providing a highly reliable quadri-layered optical disk. The quadri-layered optical disk formed in the foregoing method is set in the optical disk reproducing device shown in FIG. 6, and the light beam 13 is projected from the side of the disk sheet 6, so that the light beam 19 is focused onto the respective recording faces 10 to reproduce information recorded in the bit pattern of protrusions and recessions. As a result, the recording face 6a on the light incident side shows the bit error rate of 1.7×10−4 , and the bit error rate (BER: Bit Error Rate) of 1×10−5 to 2×10−5 can be obtained at each of other recording faces 6a. Namely, the bit error rate in the practical level can be obtained in any of the recording faces 6a of these four disk sheets 6. Next, the quadri-layered optical disks in accordance with the seventh embodiment and the eighth embodiment are placed on the plate surface, and on the surface where the disk substrate 5 is exposed, a needle with a semicircular leading end (curvature radius of 0.06 mm) is depressed vertically with a fixed pressure, and in this state, the quadri-layered optical disk is moved in parallel to move the needle from the surface of the disk substrate 5 relatively in the direction of the disk sheet 6. Then, the differences between the quadri-layered optical disk in accordance with the seventh embodiment and the quadri-layered optical disk in accordance with the present embodiment are checked. As a result, in the quadri-layered optical disk in accordance with the seventh embodiment which as a vertical level difference of substantially 0.13 mm at the edge portion of the disk sheet layer 4, and the needle with a semicircular leading end (curvature radius of 0.06 mm) is caught at the vertical level difference of the edge portion. As a result, the disk sheet layer 4 is separated from the disk substrate 5 and adjacent disk sheets 6 are separated at the edge portion as the quadri-layered optical disk is moved parallel. In contrast, the quadri-layered optical disk in accordance with the eighth embodiment, the edge portion of the disk sheet layer 4 is formed in the slope, and the edge portion of each disk sheet 6 has a level difference of substantially 0.033 mm, which is smaller than the curvature radius of 0.06 mm at the leading end of the needle. Therefore, the needle moves smoothly along the slope without being caught by the level difference of the disk sheet 6, and the separation of the disk sheet layer 4 from the disk substrate 5 or separation between the adjacent disk sheets 6 are not observed. As described, according to the quadri-layered optical disk in accordance with the eighth embodiment, in such event of, for example, an accidental drop, etc., and the disk sheet edge portion is subjected to an impact, etc., as the vertical level difference is small at the disk sheet edge portion, such problem of the disk sheet 6 being caught by a hit substance and separated can be avoided. Ninth Embodiment Specifically, after spin-coating the surface of the upper most disk sheet 6 with the acrylic series ultraviolet ray curing resin, an ultraviolet ray is projected, to form the protective layer 20 made of ultraviolet ray curing resin layer formed in the thickness of 20 μm. As a result, the quadri-layered optical disk having the structure shown in FIG. 20 is formed. Here, the protective film 52 is formed at 23 mm to the outer circumferential end of the disk so as to cover the surface, and inner and outer circumferential ends of the disk sheet layer 4. With respect to the foregoing quadri-layered optical disk having formed thereon the protective film 52, information is reproduced in the same manner as the seventh embodiment. As a result, it can be confirmed that all the recording faces 6a show the bit error rate (BER: Bit Error Rate) in a range of 4×10−5 to 7×10−5. The reason why desirable effect can be achieved from the structure of the present invention is that the light beam is incident on the surface of the protective film 52, and the light beam spot on the light incident surface becomes enlarged, whereby an occurrence of an error due to the scratch or dust particles on the light incident surface can be suppressed. The quadri-layered optical disk in accordance with the seventh embodiment, and the quadri-layered optical disk in accordance with the ninth embodiment are placed on the plane, and a steel ball with a diameter of 1 cm is dropped onto the inner circumferential ends of these disks at the height of 50 cm, and the disk sheet separation test is performed against an impact. In the quadri-layered optical disk in accordance with the seventh embodiment, after the steel ball is dropped ten times, the disk sheet layer 4 is separated from the disk substrate 5, and the adjacent disk sheets 6 are separated. In contrast, as to the quadri-layered optical disk with the protective sheet 52 in accordance with the ninth embodiment, only a fine separation is observed after the steel ball is dropped 55 times. It is therefore confirmed that the protective film 52 can prevent the separation of the disk sheet layer 4 from the disk substrate 5, and the separation of the adjacent disk sheets 6. Incidentally, the same effects as achieved from the present embodiment can be achieved also when adopting the protective sheet as the protective film 52. Tenth Embodiment With respect to the quadri-layered optical disk in accordance with the eighth embodiment, a protective sheet 52 made of polycarbonate resin is formed in the thickness of 30 μm is laminated on the surface of the upper most disk sheet 6 using an adhesive agent made of acrylic ultraviolet ray curing resin. As a result, the quadri-layered optical disk having the structure shown in FIG. 21 is formed. With respect to the foregoing quadri-layered optical disk having formed thereon the protective sheet 52, information is reproduced in the same manner as the seventh embodiment. As a result, it can be confirmed that all the recording faces 6a show the bit error rate (BER: Bit Error Rate) in a range of 1×10−5 to 3×10−5. The reason why desirable effect can be achieved from the structure of the present invention is that the light beam is incident on the surface of the protective film 52, and the light beam spot on the light incident surface becomes enlarged, whereby an occurrence of an error due to the scratch or dust particles on the light incident surface can be suppressed. The quadri-layered optical disk in accordance with the eighth embodiment, and the quadri-layered optical disk in accordance with the tenth embodiment are placed on the plane, and a steel ball with a diameter of 1 cm is dropped onto the inner circumferential ends of these disks respectively at the height of 50 cm, and the disk sheet separation test is performed against an impact. In the quadri-layered optical disk in accordance with the eighth embodiment, after the steel ball is dropped twenty times, the disk sheet layer 4 is separated from the disk substrate 5, and the adjacent disk sheets 6 are separated. In contrast, as to the quadri-layered optical disk with the protective sheet 52 in accordance with the ninth embodiment, only a fine separation is observed after the steel ball is dropped 150 times. It is therefore confirmed that the protective sheet 52 can prevent the separation of the disk sheet layer 4 from the disk substrate 5, and the separation of the adjacent disk sheets 6. Incidentally, the same effects as achieved from the present embodiment can be achieved also when adopting the protective sheet as the protective film 52. Eleventh Embodiment As a multi-layered optical disk in accordance with the eighth embodiment, prepared is an optical disk having the structure shown in FIG. 24. In the present embodiment, the disk substrate 5 made of polycarbonate is prepared such that the inner circumferential region with a width of 5 mm and the outer circumferential region with a width of 2 mm are formed thicker than the region where the disk sheets 6 are formed. Specifically, the inner circumferential region and the outer circumferential region are formed in the thickness of 1.15 mm, and the region where the disk sheet 6 is formed is formed in the thickness of 1.0 mm. The fourth kinds of the disk sheets 6 formed in the same manner as the seventh embodiment respectively have the inner diameter of 27 mmφ and an outer diameter of 114 mmφ, and the disk sheets 6 are laminated on the thinner region of the disk substrate 5 using the adhesive agent 7 made of acrylic ultraviolet ray curing resin. Then, the recording/reproducing characteristics of the quadri-layered optical disk in the present embodiment are tested. As a result, desirable recording/reproducing characteristics are obtained as in the case of the seventh embodiment. Another text is performed by repeating the installation and removal of the quadri layered optical disk in accordance with the present embodiment with respect to the CD disk case in the same manner as the seventh embodiment. As a result, the separation of the disk sheet layer 4 from the disk substrate 5 and the separation of the disk sheets 6 are not observed, and it is confirmed that the separation of the disk sheet layer 4 from the disk substrate 5 and the separation of the adjacent disk sheets 6 can be prevented also in the optical disk of the multi-layered structure. Twelfth Embodiment In the present embodiment, as illustrated in FIG. 23, acrylic ultraviolet ray curing resin is applied in the spacing between the inner circumferential region and the outer circumferential region of the disk sheet layer 4 and the disk substrate 5 in the quadri-layered optical disk in accordance with the eleventh embodiment. Thereafter, the ultraviolet ray is projected to cure the acrylic ultraviolet ray curing resin to prepare an optical disk. With respect to the quadri-layered optical disk in accordance with the eleventh embodiment and the twelfth embodiment, a test is performed by dropping the steel ball in the same manner as the ninth embodiment. In the quadri-layered optical disk in accordance with the eleventh embodiment, after the steel ball is dropped fifteen times, the disk sheet layer 4 is separated from the disk substrate 5, and the adjacent disk sheets 6 are separated. In contrast, as to the quadri-layered optical disk in accordance with the twelfth embodiment, the separation of the disk sheet layer 4 from the disk substrate 5, and separation of the adjacent optical disks are not observed even after the steel ball is dropped 150 times. It is therefore confirmed that the protective sheet 52 can prevent the separation of the disk sheet layer 4 from the disk substrate 5, and the separation of the adjacent disk sheets 6. As can be seen from the foregoing test results, it is confirmed that by filing the space between the disk substrate 5 and the disk sheet layer 4, it is possible to still suppress the separation of the disk sheet layer 4 from the disk substrate 5 and the separation of adjacent disk sheets 6. Furthermore, by forming the protective layer 52 or the protective sheet 52 on the multi-layered optical disk in accordance with the eleventh embodiment and the twelfth embodiment, it is possible to improve the recording/reproducing characteristic, and to still suppress the separation of the disk sheets 6. As described, the optical disk in accordance with the present embodiment is characterized by including a plurality of disk sheets which are laminated, each of which has a recording face on one of the surfaces. Here, the recording face indicates the surface of the optical disk whereon information is recorded. With this structure, as compared to the conventional optical disk formed by hardening the ultraviolet ray curing resin on a substrate in sequence, a shrinkage is not liable to occur in the process of forming recording faces, and thus the disk can be maintained flat. Furthermore, as a disk sheet of a uniform thickness without a partial distortion can be selected as a disk sheet to be laminated, an interval between recording faces of the adjacent disk sheets can be maintained constant. In the optical disk, when recording or reproducing, the problem of generating coma aberration or spherical aberration of the light beam can be suppressed, thereby realizing desirable recording/reproducing characteristics. With the foregoing structure, it is preferable that a plurality of disk sheets be laminated in such a manner that-between adjacent two disk sheets, the back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces the disk surface of the other disk sheet. According to the above structure, it is possible to more surely maintain an interval between adjacent recording faces constant. It is also preferable that the back surface be formed in the plane surface. In this case, when bonding the adjacent disk sheets, as one of the bonded faces (bonding surface) is flat, it is possible to simplify the bonding process. In the foregoing structure, it is preferable that the bonding layer made of ultraviolet ray curing resin be formed between the disk substrate and the disk sheet and between adjacent disk sheets. By adopting the ultraviolet ray curing resin for the material of the adhesive layer, it is possible to reduce the time required for forming the adhesive layer. In the foregoing structure, it is preferable that the disk sheet be formed thinner than the disk substrate. In this case, by laminating a plurality of relatively thin disk sheets, it is possible to realize the optical disk of a large capacity, and to improve the mechanical strength of the optical disk. It is also preferable that a protective layer be formed so as to cover the disk sheet laminated at position most apart from the disk substrate. By forming the protective layer, the disk sheet (its recording face, in particular) can be protected, and the disk sheet (its recording face, in particular) can be prevented from being scratched as being hit against an external section. When recording/reproducing by projecting the light beam from the side of the upper most disk sheet, the distance between the surface of the optical disk and the recording face (the recording face formed close to the disk surface, in particular) can be increased, and it is therefore possible to increase the ratio of the spot diameter on the surface of the optical disk with respect to the sport diameter of the recording face. With this structure, when carrying out the recording or reproducing operation, it is therefore possible to suppress an occurrence of an error due dust particles adhering to the surface of the optical disk. As a result, desirable recording/reproducing characteristics can be achieved. In the foregoing structure, it is preferable that the protective layer be made up of ultraviolet ray curing resin. According to this structure, it is possible to form the protective layer in the simple process at low costs. For example, when laminating the plurality of disk sheets on the disk substrate, ultraviolet ray curing resin is applied onto the disk sheet in the simple manner, for example, by the spin coating method, and an ultraviolet ray is then projected to form the ultraviolet ray curing resin layer in a uniform thickness. In this way, it is possible to form the protective layer at low costs. For the protectively layer, a transparent ultraviolet ray curing resin layer may be adopted, and by projecting the light beam from the side of the protective layer using the objective lens with a high NA, it is possible to record/reproduce information. As a result, the protective layer corresponding to the objective lens with high NA (0.8 or above, for example) can be formed. In the foregoing structure, it is preferable that the protective layer be a protective sheet bonded to an upper most disk sheet. According to this structure, it is possible to realize a still more uniform thickness of the protective layer. Variations in thickness of the layer cause an increase in the coma aberration or the spherical aberration of the focused light beam projected from the side of the protective layer when recording or reproducing, and recording/reproducing characteristics are adversely affected. In response, by laminating the protective sheet in the uniform thickness to the upper most disk sheet, variations in thickness of the protective layer can be suppressed, and desirable recording/reproducing characteristics can be realized. In the foregoing structure, it is preferable to arranged such that a recording face of the upper most disk sheet laminated at position most apart from the disk substrate is formed on the side of the disk substrate; and the upper most disk sheet is formed thicker than other disk sheet. In this structure, the upper most disk sheet which is formed thicker than other disk sheet functions as the protective layer. According to the foregoing structure, the recording face of the disk sheet or other disk sheet can be protected by the upper most disk sheet, and the recording face of the disk sheet can be prevented from being scratched by an impact from an external section. When recording/reproducing by projecting the light beam from the side of the upper most disk sheet, the distance between the surface of the optical disk and the recording face (the recording face formed close to the disk surface, in particular) can be increased, and it is therefore possible to increase the ratio of the spot diameter on the surface of the optical disk with respect to the sport diameter of the recording face. With this structure, when carrying out the recording or reproducing operation, it is therefore possible to suppress an occurrence of an error due dust particles adhering to the surface of the optical disk. As a result, desirable recording/reproducing characteristics can be achieved. It is needless to mention that each of the foregoing structures as described as the present invention may be combined with other structure according to the need. As described, the optical disk of the present invention is arranged such that the inner diameter of the disk sheet layer is larger than the inner diameter of the disk substrate, the disk sheet layer can be prevented from being separated from the disk substrate or from the adjacent disk sheet layer at the central hole of the optical disk, and thus the effect of providing a highly reliable optical disk. Namely, in the case where the inner diameter of the disk sheet layer is equal to the inner diameter of the disk substrate, or the inner diameter of the disk sheet layer is smaller than the inner diameter of the disk substrate, when fixing and holding the optical disk, a jig contacts the central hole of the disk sheet layer, which causes a separation of the disk sheet. In contrast, in the case where the inner diameter of the disk sheet layer is larger than the inner diameter of the disk substrate, the jig contacts only the central hole of the disk substrate, and does not contact the central hole of the disk sheet layer, thereby suppressing the problem of the separation of the disk sheet. According to the present invention wherein the outer diameter of the disk sheet layer is smaller than the outer diameter of the disk substrate, the disk sheet layer can be prevented from being separated from the disk substrate or from the adjacent disk sheet layer at an outer circumference of the optical disk, and thus the effect of providing a highly reliable optical disk can be achieved. Namely, in the case where the outer diameter of the disk sheet layer is equal to the outer diameter of the disk substrate or the outer diameter of the disk sheet layer is larger than the outer diameter of the disk substrate, when fixing and holding the optical disk, the disk sheet layer contacts a jig, which causes a separation of the disk sheet. In contrast, in the case where the outer diameter of the disk sheet layer is smaller than the outer diameter of the disk substrate, the jig contacts only the outer circumference of the disk substrate, and does not contact the outer circumference of the disk sheet layer, thereby suppressing the problem of the separation of the disk sheet. According to the present invention wherein the plurality of disk sheets of the disk sheet layer are laminated in such a manner that the further from the disk substrate in a laminating direction, the larger is the inner diameter of the disk sheet. With this structure, the problem of the unspecified substances being caught at outer circumferential edges of the disk sheet layer, which in turn causes the problem of a separation of the disk sheet layer from the disk substrate, and from the adjacent disk sheet can be suppressed. As a result, a highly reliable optical disk can be realized. According to the present invention wherein the plurality of disk sheets of the disk sheet layer are laminated in such a manner that the further from the disk substrate in a laminating direction, the smaller is the outer diameter of the disk sheet. With this structure, the problem of the unspecified substances being caught at outer circumferential edges of the disk sheet layer, which in turn causes the problem of a separation of the disk sheet layer from the disk substrate, and from the adjacent disk sheet can be suppressed. As a result, a highly reliable optical disk with an improved mechanical strength can be realized. According to the present invention wherein the protective layer is provided so as to cover the ends in the radius direction of the disk sheet layer. With this structure, the foregoing problem of the unspecified substances being caught at outer circumferential edges of the disk sheet layer, which in turn causes the problem of a separation of the disk sheet layer from the disk substrate, and from the adjacent disk sheet can be more surely suppressed. As a result, a highly reliable optical disk can be realized. Namely, as the ends in the disk radius direction of the disk sheet layer is covered with the protective layer, even when unspecified substances hit the ends and caught by the protective layer, the separation of the disk sheet layer, etc., can be prevented. According to the present invention wherein at least either the inner circumferential region and the outer circumferential region on the disk substrate is formed thicker than other region of the disk substrate, it is possible to increase the mechanical strength of the inner circumferential region, or the outer circumferential region or both the inner circumferential region and the outer circumferential region, thereby suppressing a damage of the disk substrate when being accidentally dropped or set in the recording/reproducing device. Namely, by forming the disk sheets in the above other region of the disk substrate, the disk sheet layer can be protected by at least one of the inner circumferential region and the outer circumferential region. As a result, the optical disk can be prevented from being scratched when accidentally dropped or installed in the recording/reproducing device. As described, the optical disk in accordance with the present embodiment is characterized by including a plurality of disk sheets which are laminated, each of which has a recording face on one of the surfaces. With this structure wherein a plurality of disk sheets, each having a recording face, are laminated, a shrinkage is not liable to occur in the process of forming recording faces, and thus the disk can be maintained flat. As described, the method of manufacturing the optical disk of the present invention includes a recording face forming process of forming a recording face of the optical disk on a sheet material for use in forming a disk sheet of a sheet-like disk body, a laminating process of forming a laminated structure made up of a plurality of sheet materials, each having a recording face, and a process of cutting off the laminated structure of the plurality of disk sheets, each having a recording face. According to the foregoing method, the recording face is formed on the sheet member by the recording face forming process, and further by laminating the plurality of sheet materials, each having a recording face formed thereon, multi-layered recording faces can be realized. As a result, the improved flatness of the disk can be maintained without generating the problem of the shrinkage in the recording face forming process. Furthermore, as a disk sheet of a uniform thickness without a partial distortion can be selected as a disk sheet to be laminated, an interval between recording faces of the adjacent disk sheets can be maintained constant. The invention being thus described, it will be obvious that the same way may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>A conventional manufacturing method of an optical disk 200 having a plurality of recording faces will be explained in reference to FIGS. 25 ( a ) to 25 ( c ), and FIGS. 26 ( a ) and 26 ( c ) (see, for example, Japanese Laid-Open patent Japanese Unexamined Patent Publication No. 2001-134981 (Tokukai 2001-134981 published on May 18, 2001). Firstly, a first substrate 100 having formed thereon recording pits 101 is formed by the injection molding method or the 2P method, and then a first reflective film 102 is formed so as to cover the first pits. 101 (see FIG. 25 ( a )), thereby forming a recording face 201 . Next, on the first substrate 100 having formed thereon the first reflective film 102 , an original substrate 104 is placed with a predetermined interval (see FIG. 25 ( b )). On this original substrate 104 , formed are second bits 105 having recorded thereon different information from that of the first pits 101 (see FIG. 25 ( b )). Thereafter, a recording layer 103 is formed by filling the space between the first substrate 100 and the original substrate 104 with ultraviolet ray curing resin, and hardening the ultraviolet ray curing resin by projecting thereon an ultraviolet ray ( FIG. 25 ( c )). Next, after removing the original substrate 104 , a second reflective film 106 is formed on the first recording layer 103 having copied thereto the second recording pits 105 are copied, thereby forming a recording face 205 . The first substrate 100 on which the recording face 201 and the recording face 205 are formed, and a second substrate 107 on which a recording face 208 having formed thereon the third pits 108 and the third reflective film 109 is formed are placed with a predetermined interval in between so that the recording face 205 and the recording face 208 face each other ( FIG. 26 b ). The space between the first substrate 100 and the second substrate 107 is filled with ultraviolet ray curing resin 110 . Then, the recording layer 110 is hardened by projecting thereon an ultraviolet ray so as to connect the first substrate 100 and the second substrate 107 together (see FIG. 26 ( c )). In the foregoing process, an optical disk 200 including the first recording face 201 having formed thereon the first bits 101 , a recording face 205 having formed thereon the second pits 105 , and the recording face 208 having formed thereon the third pits 108 can be manufactured. In the foregoing conventional example, explanations will be given through the case of the method of forming an optical disk with the three-layered recording face. However, by repeating the foregoing copying process, it is possible to form an optical disk having a greater number of recording faces. However, the optical disk 200 formed by the foregoing manufacturing process has the following problems as will be explained below. a) The optical disk 200 cannot be maintained flat. b) An interval between adjacent recording faces cannot be controlled with high precision. Problem a) Generally, it is necessary to form the first recording layer 103 and the second recording layer 110 in a thickness of around 10 μm for the purpose of preventing an interlayer cross light or interlayer crosstalk generated when recording or reproducing. In the foregoing method, when forming the first recording layer 103 , the space between the first substrate 100 and the original substrate 104 is filled with liquid ultraviolet ray curing resin, and hardening the resin with an application of an ultraviolet ray. Here, a problem arises in that the recording layer 103 shrinks in the hardening process with an application of the ultraviolet ray. The foregoing problem of shrinkage arises also in the process of forming the recording layer 110 . For example, in the case where the recording layer 103 and the recording layer 110 are formed in a thickness of 20 μm, the optical disk 200 is tilted to a large extent due to the shrinkage when hardening, and it becomes no longer possible to maintain the disk flat. Furthermore, when forming other recording layer 103 in addition to the recording layers 103 and 110 , the optical disk 200 would be tilted to a larger extent. When adopting the foregoing disk 200 with the foregoing problems of a large tilt which makes it difficult to maintain the disk 200 flat, coma aberration of the light beam would be increased, which makes it difficult to form a desirable light beam spot, thereby deteriorating the recording/reproducing characteristics. Problem b) According to the foregoing manufacturing method, in the process of filling the space between the first substrate 100 and the original substrate 104 with liquid ultraviolet ray curing resin, the original substrate 104 and the first substrate 100 are liable to be partially distorted. The foregoing partial distortion results in uneven interval between the original substrate 104 and the first substrate 100 , i.e., the thickness of the first recording layer 103 . Furthermore, in the process of connecting the substrates together as shown in FIG. 26 ( c ), it is necessary to carry out the process of hardening the second recording layer 100 in the state different from that shown in FIG. 25 ( c ). Namely, in the state shown in FIG. 25 ( c ), the ultraviolet ray curing resin filled in the space between the first substrate 100 (generally made of plastics) and the original substrate 104 (generally metal plate or glass plate). In contrast, in the state shown in FIG. 26 ( c ), the ultraviolet ray curing resin filled in the space between the first substrate 100 and the second substrate 107 (generally made of plastic) is hardened. As described, when carrying out the process of hardening the recording layers under different conditions, such hardening conditions as a rise in temperatures when hardening, etc., are liable to change, and it is difficult to form the first recording layer 103 and the second recording layer 110 in the same thickness. As described, in the foregoing conventional manufacturing process, the thickness of each recording layer becomes partially uneven, or the thickness between recording layers becomes uneven, which results in such problem that the interval between the adjacent recording faces cannot be controlled with high precision. When adopting the foregoing optical disk manufactured by the conventional method, in which an interval between the recording faces varies, a spherical aberration occurs in the light beam when recording/reproducing, resulting in the problem of increasing a focused beam spot diameter or deterioration in recording/reproducing characteristics. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide an optical disk which is flat and has a fixed interval between recording faces, and which permits the problems of coma aberration, spherical aberration, etc., to be suppressed, and an optical disk recording/reproducing device adopting the same. In order to achieve the foregoing object, an optical disk of the present invention is characterized by including: a plurality of disk sheets which are laminated, and each of which has a recording face on one of the surfaces, wherein: the plurality of disk sheets are laminated in such a manner that between adjacent two disk sheets, a back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces the disk surface of the other disk sheet. According to the foregoing structure of the optical disk, a plurality of disk sheets, each having a recording face, are laminated. With this structure, as compared to the conventional optical disk formed by hardening the ultraviolet ray curing resin on a substrate in sequence, a shrinkage is not liable to occur in the process of forming recording faces, and thus the disk can be maintained flat. Furthermore, as a disk sheet of a uniform thickness without a partial distortion can be selected as a disk sheet to be laminated, an interval between recording faces of the adjacent disk sheets can be maintained constant. In the optical disk, when recording or reproducing, the problem of generating coma aberration or spherical aberration of the light beam can be suppressed, thereby realizing desirable recording/reproducing characteristics. Furthermore, with the structure wherein a plurality of disk sheets are laminated in such a manner that between adjacent two disk sheets, the back surface of one of the disk sheets, on the opposite side of the surface where the recording face is formed, faces the disk surface of the other disk sheet, an interval between adjacent recording faces can be more surely maintained constant. In order to achieve another object, another optical disk in accordance with the present invention is characterized by including: a disk substrate; a disk sheet layer made up of plurality of layers laminated on the disk substrate, each having a recording face, wherein an inner diameter of the disk sheet layer is larger than an inner diameter of the disk substrate. According to the foregoing structure wherein the inner diameter of the disk sheet layer is larger than the inner diameter of the disk substrate, the disk sheet layer can be prevented from being separated from the disk substrate or from the adjacent disk sheet layer at the central hole of the optical disk, and thus the effect of providing a highly reliable optical disk can be achieved. Namely, in the case where the inner diameter of the disk sheet layer is equal to the inner diameter of the disk substrate, or the inner diameter of the disk sheet layer is smaller than the inner diameter of the disk substrate, when fixing and holding the optical disk, a jig contacts the central hole of the disk sheet layer, which causes a separation of the disk sheet. In contrast, in the case where the inner diameter of the disk sheet layer is larger than the inner diameter of the disk substrate, the jig contacts only the central hole of the disk substrate, and does not contact the central hole of the disk sheet layer, thereby suppressing the problem of the separation of the disk sheet. Another optical disk of the present invention is characterized by including: a disk substrate; and a disk sheet layer made up of plurality of layers laminated on the disk substrate, each having a recording face, wherein an outer diameter of the disk sheet layer is smaller than an outer diameter of the disk substrate. According to the foregoing structure, the outer diameter of the disk sheet layer is smaller than the outer diameter of the disk substrate, the disk sheet layer can be prevented from being separated from the disk substrate or from the adjacent disk sheet layer at an outer circumference of the optical disk, and thus the effect of providing a highly reliable optical disk. Namely, in the case where the outer diameter of the disk sheet layer is equal to the outer diameter of the disk substrate or the outer diameter of the disk sheet layer is larger than the outer diameter of the disk substrate, when fixing and holding the optical disk, the disk sheet layer contacts a jig, which causes a separation of the disk sheet. In contrast, in the case where the outer diameter of the disk sheet layer is smaller than the outer diameter of the disk substrate, the jig contacts only the outer circumference of the disk substrate, and does not contact the outer circumference of the disk sheet layer, thereby suppressing the problem of the separation of the disk sheet. Another optical disk of the present invention is characterized by including: a disk substrate; and a disk sheet layer made up of plurality of layers laminated on the disk substrate, each having a recording face, wherein a first region of the disk substrate where said disk substrate is formed is thinner than a second region other than said first region. With this structure, the second region of the disk substrate may be an inner circumferential region located inside a predetermined radius, an outer circumferential region located outside the predetermined radius, or both the inner circumferential region and the outer circumferential region. The second region of the disk substrate may be an inner circumferential region located inside a predetermined radius, an outer circumferential region located outside the predetermined radius, or both the inner circumferential region and the outer circumferential region. According to the foregoing structure, by setting the thickness of the second region, i.e., the inner circumferential region located inside the predetermined radius, the outer circumferential region located outside the predetermined radius, or both the inner circumferential region and the outer circumferential region, thicker than the first region where the disk sheet layer is formed, it is possible to increase the mechanical strength of the inner circumferential region, or the outer circumferential region or both the inner circumferential region and the outer circumferential region, thereby suppressing a damage of the disk substrate when being accidentally dropped or set in the recording/reproducing device. With a combined use of the optical disk and the recording/reproducing device of the optical disk, the present invention permits information to be recorded/reproduced on or from the optical disk of multilayered structure having a plurality of recording faces in the disk sheet layer, thereby realizing a large capacity optical disk. For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings. | 20040713 | 20101228 | 20050120 | 99575.0 | 0 | SIMPSON, LIXI CHOW | OPTICAL DISK AND OPTICAL DISK RECORDING AND REPRODUCING DEVICE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,891,014 | ACCEPTED | Nitride-based light emitting device, and method of manufacturing the same | A nitride-based light emitting device having a light emitting layer between an N-type clad layer and a P-type clad layer is provided. The light emitting device including: a reflective layer which reflects light emitting from the light emitting layer; and at least one metal layer which is formed between the reflective layer and the P-type clad layer. | 1. A nitride-based light emitting device having a light emitting layer between an N-type clad layer and a P-type clad layer, the light emitting device comprising: a reflective layer which reflects light emitting from the light emitting layer; and at least one metal layer which is formed between the reflective layer and the P-type clad layer. 2. The light emitting device of claim 1, wherein the metal layer comprises any one selected from the first metal group consisting of zinc, indium and tin. 3. The light emitting device of claim 2, wherein the metal layer is the addition of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, to any one selected from the first metal group. 4. The light emitting device of claim 3, wherein an addition ratio of the second metal group to the first metal group is 0.1 to 51 atomic percentages. 5. The light emitting device of claim 1, wherein the reflective layer is formed of silver. 6. The light emitting device of claim 1, wherein the reflective layer is formed of rhodium. 7. The light emitting device of claim 1, wherein the metal layer comprises: a first metal layer formed on the P-type clad layer; and a second metal layer formed between the first metal layer and the reflective layer, the first metal layer is formed of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, and the second metal layer is formed of any one of selected from the first metal group consisting of zinc, indium and tin. 8. The light emitting device of claim 7, wherein the second metal layer is formed by addition of any one selected from the second metal group to any one selected from the first metal group. 9. The light emitting device of claim 1, wherein the metal layer and the reflective layer have a thickness of 0.1 nm to 10 μm . 10. The light emitting device of claim 1, wherein the N-type clad layer is formed on a substrate that is formed of light transmission material. 11. The light emitting device of claim 10, wherein the substrate is formed of sapphire. 12. A method of manufacturing a nitride-based light emitting device having a light emitting layer between an N-type clad layer and a P-type clad layer, the method comprising: forming at least one metal layer on the P-type clad layer of a light emitting structure with the N-type clad layer, the light emitting layer and the P-type clad layer sequentially layered on a substrate; forming a reflective layer on the metal layer; and annealing the resultant layer structure having the reflective layer. 13. The method of claim 12, wherein the metal layer comprises any one selected from the first metal group consisting of zinc, indium and tin. 14. The method of claim 13, wherein the metal layer is the addition of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, to any one selected from the first metal group. 15. The method of claim 14, wherein an addition ratio of the second metal group to the first metal group is 0.1 to 51 atomic percentages. 16. The method of claim 12, wherein the reflective layer is formed of silver. 17. The method of claim 12, wherein the reflective layer is formed of rhodium. 18. The method of claim 12, wherein the forming of the metal layer comprises: forming a first metal layer on the P-type clad layer; and forming a second metal layer between the first metal layer and the reflective layer, the first metal layer is formed of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, and the second metal layer is formed of anyone of selected from the first metal group consisting of zinc, indium and tin. 19. The method of claim 18, wherein the second metal layer is formed by addition of any one selected from the second metal group to any one selected from the first metal group. 20. The method of claim 12, wherein the metal layer and the reflective layer have a thickness of 0.1 nm to 10 μm . 21. The method of claim 12, wherein the N-type clad layer is formed on a substrate that is formed of light transmission material. 22. The method of claim 21, wherein the substrate is formed of sapphire. 23. The method of claim 12, wherein the annealing is performed at 20° C. to 700° C. 24. The method of claim 23, wherein the annealing is performed in gas atmosphere containing at least one of nitrogen, argon, helium, oxygen, hydrogen, and air within a reactor in which the layer structure is installed. | This application claims the priority of Korean Patent Application No. 2003-58841, filed on Aug. 25, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitride-based light emitting device and a method of manufacturing the same, and more particularly, to a nitride-based light emitting device having an Ohmic contact structure for increasing a quantum efficiency, and a method of manufacturing the same. 2. Description of the Related Art In order to embody a light emitting device such as a light emitting diode or a laser diode by using a nitride-based compound semiconductor, for example, a gallium nitride (GaN) semiconductor, Ohmic contact structure between a semiconductor and an electrode is of much importance. A gallium nitride-based light emitting device is formed on an insulating sapphire (Al2O3) substrate. The gallium nitride-based light emitting device is classified into Top-Emitting Light Emitting Diodes (TLEDs) and Flip-Chip Light Emitting Diodes (FCLEDs). The top-emitting light emitting diode allows light to emit through an Ohmic electrode layer that is in contact with a P-type clad layer, and provides a low electric conductivity of the P-type clad to allow smooth current injection through the Ohmic electrode layer with transparency and low resistance. The top-emitting light emitting diode is generally employing a structure of a nickel (Ni) layer and a gold (Au) layer sequential layered on the P-type clad layer. The nickel layer is known in the art to form a semi-transparent Ohmic contact layer that is annealed in oxygen (O2) atmosphere to have a relative contact resistance of about 10−3-10−4 Ωcm2. When the semi-transparent Ohmic contact layer is annealed at about 500-600° C. in the oxygen atmosphere, the semi-transparent Ohmic contact layer provide a low relative contact resistance between the gold (Au) layer and a lower layer portion where the nickel oxide (NiO) is island-shaped as a P-type semiconductor oxide between the gallium nitride that forms the P-type clad layer and the nickel layer that is used as the Ohmic contact layer. Accordingly, a Schottky Barrier Height (SBH) is reduced, thereby facilitate to supply holes as a majority carrier in the vicinity of a surface of the P-type clad layer. As a result, an effective carrier concentration is increased in the vicinity of the surface of the P-type clad layer. Further, after the nickel layer and the gold layer are formed on the P-type clad layer, a reactivation process using the annealing is performed to remove a Mg—H compound to thereby increase a concentration of Magnesium dopants at a surface of the gallium nitride. As a result, the effective carrier concentration of above 1019 is obtained at the surface of the P-type clad layer. Therefore, tunneling conduction is generated between the P-type clad layer and the Ohmic electrode layer that contains nickel oxide to provide an Ohmic conduction characteristic. However, since the top-emitting light emitting diode using a semi-transparent electrode film formed of nickel/gold has a low optic efficiency, it is difficult to embody a large-capacity and high-luminance light emitting device. In order to embody the large-capacity and high-luminance light emitting device, a flip-chip light emitting device using silver (Ag) or aluminum (Al) that is noticed as a high reflective material is being recently required for development. However, silver or aluminum can temporarily provide a high light-emitting efficiency due to its high reflection efficiency, but there is a drawback in that a device life is short since it is difficult to form an Ohmic contact with a lower resistance due to a small work function, and a stable device reliability is not provided since the adhesiveness with the gallium nitride is poor. In order to solve the above drawback, an Ohmic contact layer providing the high reflectivity despite the low relative contact resistance is being vigorously studied for development. U.S. Patent Publication No.: 2002-0190260A1 discloses a structure with nickel/silver sequential layered on the P-type clad layer, but has a drawback in that contact resistance is high, and adhesiveness is low at the time of annealing. SUMMARY OF THE INVENTION The present invention provides a nitride-based light emitting device having an electrode structure for providing a low resistance characteristic and a high reflectivity, and a method of manufacturing the same. According to an aspect of the present invention, there is provided a nitride-based light emitting device having a light emitting layer between an N-type clad layer and a P-type clad layer, the light emitting device including: a reflective layer which reflects light emitting from the light emitting layer; and at least one metal layer which is formed between the reflective layer and the P-type clad layer. The metal layer comprises any one selected from the first metal group consisting of zinc, indium and tin. The metal layer is the addition of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, to any one selected from the first metal group. An addition ratio of the second metal group to the first metal group is 0.1 to 51 atomic percentages. The reflective layer is formed of silver or rhodium. The metal layer includes: a first metal layer formed on the P-type clad layer; and a second metal layer formed between the first metal layer and the reflective layer, the first metal layer is formed of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, and the second metal layer is formed of any one of selected from the first metal group consisting of zinc, indium and tin. The second metal layer is formed by addition of any one selected from the second metal group to any one selected from the first metal group. The metal layer and the reflective layer have a thickness of 0.1 nm to 1 μm. The N-type clad layer is formed on a substrate that is formed of light transmission material. In another aspect of the present invention, there is provided a method of manufacturing a nitride-based light emitting device having a light emitting layer between an N-type clad layer and a P-type clad layer, the method including: forming at least one metal layer on the P-type clad layer of a light emitting structure with the N-type clad layer, the light emitting layer and the P-type clad layer sequentially layered on a substrate; forming a reflective layer on the metal layer; and annealing the resultant layer structure having the reflective layer. The annealing may be performed at 20° C. to 700° C., and the annealing may be performed in gas atmosphere containing at least one of nitrogen, argon, helium, oxygen, hydrogen, and air within a reactor in which the layer structure is installed. BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. 1 is a sectional view illustrating a P-type electrode structure according to an embodiment of the present invention; FIG. 2 is a sectional view illustrating a P-type electrode structure according to another embodiment of the present invention; FIGS. 3 through 5 are graphs illustrating current-voltage characteristics measured before and after a P-type electrode structure of FIG. 1 is annealed; FIG. 6 is a graph illustrating an Auger depth profile after a zinc-nickel alloy/silver is deposited on a P-type clad layer, and then annealed at 500° C. for one minute in air atmosphere; FIG. 7 is a sectional view illustrating a varied layer structure after a P-type electrode structure is annealed according to an Auger depth profile of FIG. 6; FIG. 8 is a sectional view illustrating a light emitting device employing a P-type electrode structure according to an embodiment of the present invention; FIG. 9 is a sectional view illustrating a light emitting device employing a P-type electrode structure according to another embodiment of the present invention; and FIG. 10 is a graph illustrating the comparative result of current-voltage characteristics of light emitting devices with a zinc-nickel alloy/silver deposited and annealed in air atmosphere and with only silver deposited and annealed in air atmosphere. DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. FIG. 1 is a sectional view illustrating a P-type electrode structure with a metal layer and a reflective layer each having a different thickness according to an embodiment of the present invention. Referring to FIG. 1, the P-type electrode structure includes a metal layer 30 and a reflective layer 40. In FIG. 1, the P-type electrode structure includes a III-group nitride-based P-type clad layer 20 formed on a substrate 10; and the metal layer 30 and the reflective layer 40 sequentially layered on the P-type clad layer 20. A characteristic experiment is made between the P-type clad layer 20 and the P-type electrode structure 30 and 40. The P-type clad layer 20 is required to have an improved Ohmic characteristic among an N-type clad layer and the P-type clad layer that face with each other centering on a light emitting layer of the III-group nitride-based light emitting device. The P-type clad layer 20 uses III-group nitride compound with P-type dopants being doped. Here, the III-group nitride compound is expressed in a general formula AlxInyGazN (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦x+y+z≦1). Further, the P-type dopant can use Mg, Zn, Ca, Sr, Ba and the like. The metal layer 30 can employ metal or alloy that has a good reaction with the P-type clad layer 30. The metal layer 30 may employ metal, which can increase an effective carrier concentration of the P-type clad layer 20 and has a good primary reaction with a component, excepting for nitride, among the III-group nitride compound of the P-type clad layer 20. For example, when the metal layer 30 employs a GaN-based compound, the metal layer 30 employs metal having a primary reaction with gallium (Ga) rather than nitride (N). As one example, the P-type clad layer 20 with a main ingredient being gallium nitride (GaN) has gallium vacancy that is formed on a surface thereof by the reaction of gallium (Ga) of the P-type clad layer 20 with the metal layer 30. The gallium vacancy of the P-type clad layer 20 functions as the P-type dopants to increase the effective carrier concentration on the surface of the P-type clad layer 20 by the reaction of the P-type clad layer 20 and the metal layer 30. The metal layer 30 satisfying the above condition is formed of any one selected from the first metal group consisting of Zinc (Zn), Indium (In) and Tin (Sn). Otherwise, the metal layer 30 can be formed of alloy that has any one main ingredient selected from the first metal group and any one additional ingredient selected from a second metal group. The second metal group includes Nickel (Ni), Cobalt (Co), Copper (Cu), Palladium (Pd), Platinum (Pt), Ruthenium (Ru), Rhodium (Rh), Iridium (Ir), Tantalium (Ta), Rhenium (Re), Tungsten (W), and Lanthanum (La). An addition ratio of the second metal group to the first metal group may be within 0.1 to 51 atomic percentages. The reflective layer 40 is an uppermost layer in the P-type electrode structure. The reflective layer 40 employs material suppressing a surface degradation, being stable against oxidation, having a non-varied characteristic, and having a high reflectivity power, at 300-600° C., which is a general temperature, in a process of manufacturing a flip-chip light emitting device. The reflective layer 40 may be formed of Silver (Ag) or Rhodium (Rh) that satisfies the above condition. Furthermore, the metal layer 30 and the reflective layer 40 may have a thickness of 0.1 nm to 10 μm. The metal layer 30 and the reflective layer 40 are firmed using various well-known methods, for example, using Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD), Plasma Laser Deposition (PLD), a dual-type thermal evaporator, sputtering and the like. The metal layer 30 and the reflective layer 40 are generally deposited at a temperature of 20-1500° C. in a reactor with a pressure of atmospheric pressure to about 10-12 torr. After that, the metal layer 30 and the reflective layer 40 are annealed at 20-700° C. for one second to 10 hours in a vacuum or gas atmosphere. When the metal layer 30 and the reflective layer 40 are annealed in a reactor, at least one of nitrogen, argon, helium, oxygen, hydrogen and air is introduced into the reactor. Hereinafter, a method of manufacturing the P-type electrode structure according an embodiment of the present invention is described. However, the present invention is not limited to the method exemplified through the embodiment. First, a structure with the substrate 10 and the P-type clad layer 20, which is formed on the substrate and has the gallium nitride as the main ingredient, is surface-cleaned at 60° C. for five minutes in an ultrasonic bath using trichloroethylene, acetone, methanol, and distilled water, respectively, and then is hard-baked at 100° C. for ten minutes for dehydration. After that, the resultant structure is spin-coated at 400-500 rpm to form a photo-resist on the P-type clad layer 20. Next, the resultant is soft-baked for 15 minutes at 85° C., and a mask and a pattern are aligned to develop a mask pattern. After that, the developed resultant is exposed for 15 seconds to ultraviolet (UV) with an intensity of 22.8 mW, and then dipped for about 25 seconds into solution with a developing agent and the distilled water being mixed at a ratio of 1:4, for development. Next, the developed resultant is dipped into BOE solution for five minutes so as to remove a pollution layer. The zinc-nickel alloy is deposited in an electron-beam evaporator to form the metal layer 30 on the P-type clad layer 20 at a thickness of 10 nm, and then silver is deposited on the metal layer 30 in the electron-beam evaporator to form the reflective layer 40 at a thickness of 10 nm. After that, the resultant is processed in a lift-off process using acetone, and then is annealed using a Rapid Thermal Annealing (RTA) at 500° C. for one minute in air atmosphere to manufacture the P-type electrode structure using Ohmic contact. FIG. 2 is a sectional view illustrating a P-type electrode structure according to another embodiment of the present invention. Elements having the same functions as those of FIG. 1 are denoted using the same reference numerals. Referring to FIG. 2, a first metal layer 50, a second metal layer 30 and a reflective layer 40 are sequentially formed on a P-type clad layer 20 formed on a substrate 10. As described above, also in FIG. 2, the P-type electrode structure includes a III-group nitride-based P-type clad layer 20 that is formed on a sapphire substrate 10; and the first metal layer 50, the second metal layer 30 and the reflective layer 40 that are sequentially layered on the P-type clad layer 20. A characteristic experiment is made between the P-type clad layer 20 and the P-type electrode structure. The first metal layer 50 may be formed of any one selected from the above-described second metal group, that is, the group consisting of Nickel (Ni), Cobalt (Co), Copper (Cu), Palladium (Pd), Platinum (Pt), Ruthenium (Ru), Rhodium (Rh), Iridium (Ir), Tantalium (Ta), Rhenium (Re), Tungsten (W), and Lanthanum (La). The second metal layer 30 is formed of the same material as that of the metal layer 30 described through FIG. 1. That is, the second metal layer 30 is formed of any one selected from the first metal group including Zinc (Zn), Indium (In) and Tin (Sn). Otherwise, the second metal layer 30 can be formed of any one main ingredient selected from the first metal group and any one additional ingredient selected from the above-described second metal group. The first metal layer 50, the second metal layer 30 and the reflective layer 40 have a total thickness of about 0.1 nm to 10 μm. The above P-type electrode structure performs a deposition process and an annealing process, as described above. Hereinafter, an experimental result for the above-described P-type electrode structure that is formed on the P-type clad layer 20 having the gallium nitride (GaN) as the main ingredient is described with reference to FIGS. 3 through 5. FIGS. 3 through 5 are graphs illustrating measurement results of electrical characteristics before and after the P-type electrode structure is annealed in air atmosphere. In the P-type electrode structure, the metal layer 30 is deposited using the zinc-nickel alloy on the P-type clad layer 20 and then, the reflective layer 40 is deposited using silver on the metal layer 30. The metal layer 30 and the reflective layer 40 are formed to have a different thickness, respectively. The P-type clad layer 20 has the main ingredient of the gallium nitride (GaN) with a carrier concentration of 4-5×1017cm−3. FIG. 3 is a measurement result of the current-voltage characteristic in the P-type electrode structure having the metal layer 30 with a thickness of 10 nm, and the reflective layer 40 with a thickness of 10 nm. FIG. 4 is a measurement result of the current-voltage characteristic in the P-type electrode structure having the metal layer 30 with a thickness of 2.5 nm, and the reflective layer 40 with a thickness of 100 nm. FIG. 5 is a measurement result of the current-voltage characteristic in the P-type electrode structure having the metal layer 30 with the thickness of 2.5 nm, and the reflective layer 40 with a thickness of 200 nm. As appreciated from the drawings, the current-voltage characteristic after annealing is more improved than that before annealing, and the P-type electrode structure has a low relative contact resistance of 10−4 to 10−5 Ωcm2. In order to analyze a cause of improving a relative contact resistance after annealing, FIG. 6 illustrates a measurement result of an Auger depth profile depending on a depth using an Auger spectroscope after the P-type electrode structure is annealed at 500° C. for one minute in air atmosphere. In the P-type electrode structure, the metal layer 30 is deposited using the zinc-nickel alloy on the P-type clad layer 20, and the reflective layer 40 is deposited using silver on the metal layer 30. The metal layer 30 and the reflective layer 40 are formed to have a thickness of 10 nm, respectively. FIG. 7 illustrates a varied layer structure after the P-type electrode structure is annealed according to the Auger depth profile of FIG. 6. As appreciated from FIGS. 6 and 7, external oxygen is supplied through annealing, thereby causing the phase transformation from zinc to zinc oxide and from nickel to nickel oxide. Further, the nickel oxide and silver is diffused toward the P-type clad layer 20 to form a first metal oxide layer 51 that is in contact with the P-type clad layer 20. The zinc oxide is diffused toward the uppermost layer to form a second metal oxide layer 31. A reflective layer 41 with the main ingredient being silver is located between the second metal oxide layer 31 and the first metal oxide layer 51 that contains silver. At a room temperature, silver has −20 to 30 KJ/Kmole of enthalpy, nickel has −239 KJ/Kmole, and zinc has −350.9 KJ/Kmole. The enthalpy is energy for oxidizing metal and represents an oxidation capability. Accordingly, it can be understood that zinc and nickel are primarily oxidized at the time of annealing since they have enthalpies larger than silver by several dozens to several hundreds times. The above result is caused when the annealing process is performed after the formation of the P-type clad layer 20, and reduces gallium oxide (Ga2O3) being a natural oxide that remains on a surface of the P-type clad layer 20 while functioning as an obstacle of carrier flow at an interface between the P-type clad layer 20 and the metal layer 30 deposited thereon. Further, metal used as the metal layer 30 is oxidized to be phase-transformed into a transparent conductive or semi-transparent conductive oxide. Accordingly, transparent conductive or semi-transparent conductive metal oxide layers 31 and 51 are formed, thereby reducing Schottky barrier height and width. Besides, tunneling conduction is generated at the interface between the P-type clad layer 20 and the P-type electrode structure by the gallium vacancy formed on the surface of the P-type clad layer 20, the reduction of the natural oxide, and the formation of the transparent conductive metal oxide layers 31 and 51. As a result, the P-type clad layer 20 functions as the dopant such that an effective hole concentration can be increased in the vicinity of the surface of the P-type clad layer 20. Further, since the zinc oxide (ZnO) formed at the time of annealing in air or oxygen atmosphere and a zinc-based or magnesium-based alloy or the metal selected from the second metal group have almost the same work function as gallium nitride, the Schottky barrier height is reduced when they are in contact with the P-type clad layer 20, thereby improving an Ohmic contact characteristic and providing transmission of almost 100%. Furthermore, the second metal oxide layer 31 being the natural oxide is formed on the surface of the uppermost layer, and the first metal oxide layer 51 being in contact with the P-type clad layer 20 is formed of the second metal group oxide (for example, Ni—O, Co—O and the like) containing silver, thereby reducing the Schottky barrier height. The reduced Schottky barrier height allows a high quality of Ohmic contact. At this time, a thick silver (Ag) layer 41 is interposed between the second metal oxide layer 31 being the zinc oxide layer and the first metal oxide layer 51 being the internally diffused second metal group oxide, thereby contributing to the conductivity improvement of nickel and functioning as an excellent reflective layer in flip-chip light emitting devices (FCLEDs). FIG. 8 is a sectional view illustrating the light emitting device employing the P-type electrode structure of FIG. 1 according to an embodiment of the present invention. Referring to FIG. 8, the light emitting device includes a substrate 110, a buffer layer 120, an N-type clad layer 130, a light emitting layer 140, a P-type clad layer 150, a metal layer 230 and a reflective layer 240 that are sequentially layered. Reference numeral 180 refers to a P-type electrode pad, and reference numeral 190 refers to a N-type electrode pad. The substrate 110 is formed of sapphire or silicon carbide (SiC). The buffer 120 can be omitted. Each layer between the buffer layer 120 to the P-type clad layer 150 is based on any compound selected from compounds expressed in the general formula AlxInyGazN (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦x+y+z≦1) of the III-group nitride-based compound, and the N-type clad layer and the P-type clad layer have corresponding dopants added thereto. Further, the light emitting layer 140 can be constructed such as a single layer or a Multiple-Quantum Well (MQW) layer in the various well-known methods. As one example, the buffer layer 120 is formed of GaN, the N-type clad layer 130 is formed with N-type dopants such as Si, Ge, Se, Te being added to GaN, and the P-type clad layer 150 is formed with P-type dopants such as Mg, Zn, Ca, Sr, Ba being added to GaN. The layers are respectively formed using various well-known deposition methods, for example, PVD, CVD, PLD, dual-type thermal evaporator, and sputtering. The electrode layer 230 is formed of the first metal group or the alloy having the second metal group added to the first metal group that are described above through FIG. 1, and the reflective layer 240 is formed of silver or rhodium and then annealed. FIG. 9 is a sectional view illustrating a light emitting device employing a P-type electrode structure according to another embodiment of the present invention. Elements having the same functions are denoted by the same reference numerals. Referring to FIG. 9, the light emitting device includes a substrate 110, a buffer layer 120, an N-type clad layer 130, a light emitting layer 140, a P-type clad layer 150, a first metal layer 350, a second metal layer 330, and a reflective layer 340. The first metal layer 350 is formed of any one of the second metal group that is described above in FIG. 2. The second metal layer 330 is formed of the first metal group or the second metal group added to the first metal group that are described above through FIG. 1. The reflective layer 340 is formed of silver or rhodium. FIG. 10 is a graph illustrating the comparative result of current-voltage characteristics of light emitting devices having the zinc-nickel alloy/silver deposited and annealed in the air atmosphere, and having only silver deposited and annealed in the air atmosphere. As appreciated in FIG. 10, the light emitting device employing the above P-type electrode structure according to the present invention has an excellently improved electrical characteristic. That is, a blue-light emitting diode with an InGaN structure has the metal layer 230 formed of the zinc-nickel alloy to have the thickness of 2.5 nm and the reflective layer 240 formed of silver to have the thickness of 100 nm. The above blue-light emitting diode has an operation voltage of 3.25V at 20 mA. However, a blue-light emitting device having the reflective layer 240 formed of only silver at the thickness of 100 nm has an operation voltage larger than the 3.25V. Especially, the light emitting device having only silver deposited to have the thickness of 100 nm and then, annealed in the air atmosphere has the operation voltage greatly larger than before annealing, and has a considerable electrical degradation. Hereinafter, the present invention describes, but is not limited to, an example of manufacturing the light emitting device. First, a surface treatment and a electron beam lithography for the P-type clad layer 150 are applied, in the same manner as the aforementioned embodiment, to the light emitting structure with the substrate, the buffer layer, the N-type clad layer, the light emitting layer and the P-type clad layer that have GaN as the main ingredient, excepting for the P-type electrode structure not yet deposited. After the surface treatment and the electron beam lithography, the metal layer 230 is formed of the zinc-nickel alloy to have the thickness of 2.5 nm, and then silver is deposited on the resultant to have the thickness of 100 nm. After that, the resultants is processed by the lift-off process using acetone, and then is annealed at 500° C. for one minute in the air atmosphere in a rapid thermal annealing furnace. As a result, the light emitting diode is manufactured using the Ohmic contact. As described above, the nitride-based light emitting device and the manufacture method thereof according to the present invention provide an advantage in that the Ohmic contact characteristic with the P-type clad layer is improved to thereby enhance a wire bonding efficiency and a yield when the light emitting device is packaged, and the low relative contact resistance and the excellent current-voltage characteristic can improve a light emitting efficiency and a device life. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a nitride-based light emitting device and a method of manufacturing the same, and more particularly, to a nitride-based light emitting device having an Ohmic contact structure for increasing a quantum efficiency, and a method of manufacturing the same. 2. Description of the Related Art In order to embody a light emitting device such as a light emitting diode or a laser diode by using a nitride-based compound semiconductor, for example, a gallium nitride (GaN) semiconductor, Ohmic contact structure between a semiconductor and an electrode is of much importance. A gallium nitride-based light emitting device is formed on an insulating sapphire (Al 2 O 3 ) substrate. The gallium nitride-based light emitting device is classified into Top-Emitting Light Emitting Diodes (TLEDs) and Flip-Chip Light Emitting Diodes (FCLEDs). The top-emitting light emitting diode allows light to emit through an Ohmic electrode layer that is in contact with a P-type clad layer, and provides a low electric conductivity of the P-type clad to allow smooth current injection through the Ohmic electrode layer with transparency and low resistance. The top-emitting light emitting diode is generally employing a structure of a nickel (Ni) layer and a gold (Au) layer sequential layered on the P-type clad layer. The nickel layer is known in the art to form a semi-transparent Ohmic contact layer that is annealed in oxygen (O2) atmosphere to have a relative contact resistance of about 10 −3 -10 −4 Ωcm 2 . When the semi-transparent Ohmic contact layer is annealed at about 500-600° C. in the oxygen atmosphere, the semi-transparent Ohmic contact layer provide a low relative contact resistance between the gold (Au) layer and a lower layer portion where the nickel oxide (NiO) is island-shaped as a P-type semiconductor oxide between the gallium nitride that forms the P-type clad layer and the nickel layer that is used as the Ohmic contact layer. Accordingly, a Schottky Barrier Height (SBH) is reduced, thereby facilitate to supply holes as a majority carrier in the vicinity of a surface of the P-type clad layer. As a result, an effective carrier concentration is increased in the vicinity of the surface of the P-type clad layer. Further, after the nickel layer and the gold layer are formed on the P-type clad layer, a reactivation process using the annealing is performed to remove a Mg—H compound to thereby increase a concentration of Magnesium dopants at a surface of the gallium nitride. As a result, the effective carrier concentration of above 10 19 is obtained at the surface of the P-type clad layer. Therefore, tunneling conduction is generated between the P-type clad layer and the Ohmic electrode layer that contains nickel oxide to provide an Ohmic conduction characteristic. However, since the top-emitting light emitting diode using a semi-transparent electrode film formed of nickel/gold has a low optic efficiency, it is difficult to embody a large-capacity and high-luminance light emitting device. In order to embody the large-capacity and high-luminance light emitting device, a flip-chip light emitting device using silver (Ag) or aluminum (Al) that is noticed as a high reflective material is being recently required for development. However, silver or aluminum can temporarily provide a high light-emitting efficiency due to its high reflection efficiency, but there is a drawback in that a device life is short since it is difficult to form an Ohmic contact with a lower resistance due to a small work function, and a stable device reliability is not provided since the adhesiveness with the gallium nitride is poor. In order to solve the above drawback, an Ohmic contact layer providing the high reflectivity despite the low relative contact resistance is being vigorously studied for development. U.S. Patent Publication No.: 2002-0190260A1 discloses a structure with nickel/silver sequential layered on the P-type clad layer, but has a drawback in that contact resistance is high, and adhesiveness is low at the time of annealing. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a nitride-based light emitting device having an electrode structure for providing a low resistance characteristic and a high reflectivity, and a method of manufacturing the same. According to an aspect of the present invention, there is provided a nitride-based light emitting device having a light emitting layer between an N-type clad layer and a P-type clad layer, the light emitting device including: a reflective layer which reflects light emitting from the light emitting layer; and at least one metal layer which is formed between the reflective layer and the P-type clad layer. The metal layer comprises any one selected from the first metal group consisting of zinc, indium and tin. The metal layer is the addition of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, to any one selected from the first metal group. An addition ratio of the second metal group to the first metal group is 0.1 to 51 atomic percentages. The reflective layer is formed of silver or rhodium. The metal layer includes: a first metal layer formed on the P-type clad layer; and a second metal layer formed between the first metal layer and the reflective layer, the first metal layer is formed of any one of selected from the second metal group consisting of nickel, cobalt, copper, palladium, platinum, ruthenium, rhodium, iridium, tantalum, rhenium, tungsten, and a lanthanum-based metal, and the second metal layer is formed of any one of selected from the first metal group consisting of zinc, indium and tin. The second metal layer is formed by addition of any one selected from the second metal group to any one selected from the first metal group. The metal layer and the reflective layer have a thickness of 0.1 nm to 1 μm. The N-type clad layer is formed on a substrate that is formed of light transmission material. In another aspect of the present invention, there is provided a method of manufacturing a nitride-based light emitting device having a light emitting layer between an N-type clad layer and a P-type clad layer, the method including: forming at least one metal layer on the P-type clad layer of a light emitting structure with the N-type clad layer, the light emitting layer and the P-type clad layer sequentially layered on a substrate; forming a reflective layer on the metal layer; and annealing the resultant layer structure having the reflective layer. The annealing may be performed at 20° C. to 700° C., and the annealing may be performed in gas atmosphere containing at least one of nitrogen, argon, helium, oxygen, hydrogen, and air within a reactor in which the layer structure is installed. | 20040715 | 20081209 | 20050303 | 72153.0 | 0 | SEFER, AHMED N | NITRIDE-BASED LIGHT EMITTING DEVICE, AND METHOD OF MANUFACTURING THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,891,068 | ACCEPTED | Packaging apparatus and packaging method | In a packaging apparatus, when replacing a preceding single-faced corrugated fiberboard (wrapping material) with a subsequent single-faced corrugated fiberboard, a draw-out roller is operated such that the preceding single-faced corrugated fiberboard is drawn out to its trailing end. At this time, a reserve roller, around which the single-faced corrugated fiberboard is trained, is moved such that the single-faced corrugated fiberboard, which has been drawn out, is accumulated thereat. Then, the trailing end of the preceding single-faced corrugated fiberboard and a leading end of the subsequent single-faced corrugated fiberboard are joined together at a joining device. In this way, the preceding single-faced corrugated fiberboard can be used up until its final end, and thus there is no waste of the single-faced corrugated fiberboard. | 1. A packaging apparatus comprising: a draw-out roller drawing-out a packaging material from a packaging material roll in which the packaging material is wound-up in a form of a roll; an accumulating roller around which the packaging material drawn out by the draw-out roller is trained; moving means for moving and restraining the accumulating roller at a time when the packaging material roll is to be replaced, and for accumulating the packaging material at the accumulating roller; and a wrapping device for pulling-out the packaging material which is trained on the accumulating roller, and wrapping the packaging material around side surfaces of a loaded object which is loaded on a pallet. 2. The packaging apparatus of claim 1, wherein the accumulating roller is provided so as to be oriented vertically. 3. The packaging apparatus of claim 1, further comprising control means for stopping the accumulating roller and the draw-out roller when, after stopping of the wrapping device, a preceding packaging material is drawn out from the packaging material roll by the draw-out roller while being accumulated at the accumulating roller and a trailing end of the preceding packaging material is drawn out to a joining position at which the trailing end of the preceding packaging material is joined together with a leading end of a subsequent packaging material. 4. The packaging apparatus of claim 3, wherein a joining device, which joins together the trailing end of the preceding packaging material which has been drawn out and the leading end of the subsequent packaging material, is provided at the joining position. 5. The packaging apparatus of claim 1, wherein the packaging apparatus has, between the accumulating roller and the wrapping device, a tension applying roller for applying tension to the packaging material, and restraining means for restraining movement of the tension applying roller. 6. The packaging apparatus of claim 5, further comprising a control means, wherein, after a trailing end of a preceding packaging material and a leading end of a subsequent packaging material have been joined together, the control means releases restraining of the tension applying roller by the restraining means, and drives the wrapping device, and releases restraining of the accumulating roller by the moving means when the tension applying roller is moved past a predetermined position due to tension of the packaging material, and restrains the accumulating roller when the accumulating roller is moved to a predetermined position due to the packaging material, which has been accumulated, being drawn out. 7. The packaging apparatus of claim 1, further comprising a detecting device for detecting that a trailing end of a preceding packaging material has been drawn out to a joining position at which the trailing end of the preceding packaging material is joined together with a leading end of a subsequent packaging material. 8. A packaging apparatus comprising: a draw-out roller for drawing-out a packaging material from a packaging material roll in which the packaging material is wound-up in a form of a roll; a wrapping device for pulling-out the packaging material which has been drawn out by the draw-out roller, and wrapping the packaging material around side surfaces of a loaded object which is loaded on a pallet; a detecting device detecting that a remaining length of the packaging material has become shorter than a length needed to wrap around the side surfaces of the loaded object; a joining device joining together a trailing end of the packaging material which has been drawn out and a leading end of a subsequent, other packaging material; and a control unit, wherein, when the detecting device detects that the remaining length of the packaging material is less than the needed length, the control unit: stops the wrapping device, draws-out the packaging material from the packaging material roll by the draw-out roller, stops the draw-out roller when the trailing end of the packaging material is drawn out to a joining position at which the trailing end of the packaging material is joined together with a leading end of the other packaging material, joins together the trailing end of the packaging material and the leading end of the other packaging material by the joining device, and operates the wrapping device and the draw-out roller after joining. 9. The packaging apparatus of claim 8, further comprising an accumulating roller around which the packaging material drawn out by the draw-out roller is trained. 10. The packaging apparatus of claim 9, wherein when the detecting device detects that the remaining length of the packaging material has become less than the needed length, the control unit stops the wrapping device, and draws-out the packaging material by the draw-out roller while accumulating the packaging material at the accumulating roller. 11. The packaging apparatus of claim 9, wherein, when the trailing end of the packaging material is drawn out to the joining position at which the trailing end of the packaging material is joined together with the leading end of the other packaging material, the control unit stops the accumulating roller and the draw-out roller. 12. The packaging apparatus of claim 9, further comprising a moving unit which, when the packaging material roll is to be replaced, moves and restrains the accumulating roller, and thereby accumulates the packaging material at the accumulating roller. 13. The packaging apparatus of claim 12, wherein the packaging apparatus has, between the accumulating roller and the wrapping device, a tension applying roller for applying tension to the packaging material, and a restraining means for restraining movement of the tension applying roller. 14. The packaging apparatus of claim 13, wherein, after the joining, the control unit releases restraining of the tension applying roller by the restraining means, and drives the wrapping device, and releases restraining of the accumulating roller by the moving unit when the tension applying roller is moved past a predetermined position due to tension of the packaging material, and restrains the accumulating roller when the accumulating roller is moved to a predetermined position due to the packaging material, which has been accumulated, being drawn out. 15. The packaging apparatus of claim 8, wherein the accumulating roller is provided so as to be oriented vertically. 16. The packaging apparatus of claim 8, further comprising a detecting device for detecting that the trailing end of the packaging material has been drawn out to the joining position at which the trailing end of the packaging material is joined together with the leading end of the subsequent packaging material. 17. A packaging method for drawing a packaging material out from a packaging material roll in which the packaging material is wound-up in a form of a roll, and wrapping the packaging material around side surfaces of a loaded object which is loaded on a pallet, the packaging method comprising: when the packaging material roll is to be replaced, drawing a preceding packaging material out from the packaging material roll; and increasing an amount of the drawn-out packaging material accumulated on an accumulating roller on which the packaging material, which has been drawn out, is trained, by moving the accumulating roller. 18. The packaging method of claim 17, further comprising: detecting that a remaining length of the preceding packaging material has become shorter than a length needed to wrap around the side surfaces of the loaded object; after the detecting, stopping the wrapping of the packaging material around the side surfaces of the loaded object; drawing-out the preceding packaging material from the packaging material roll, while accumulating the preceding packaging material at the accumulating roller; stopping the accumulating roller and drawing-out of the preceding packaging material, when a trailing end of the preceding packaging material is drawn out to a joining position at which the trailing end of the preceding packaging material is joined together with a leading end of a subsequent packaging material; joining together the trailing end of the packaging material and the leading end of the subsequent packaging material; and after the joining, starting wrapping of the packaging material onto the side surfaces of the loaded object and drawing-out of the subsequent packaging material from a packaging material roll. 19. The packaging method of claim 17, further comprising of providing the accumulating roller to be oriented vertically. | CROSS-REFERENCE TO RELATED APPLICATION This application claims priority under 35 USC 119 from Japanese patent application, No. 2003-197804, the disclosure of which is incorporated by reference herein. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging apparatus and a packaging method for wrapping a packaging material around side surfaces of a loaded object which is loaded on a pallet. 2. Description of the Related Art As shown in FIG. 9, in a conventional packaging apparatus 100 for planographic printing plates, a single-faced corrugated fiberboard 102 is drawn out by nip rollers 112 from a single-faced corrugated fiberboard roll 102A which is wound up in the shape of a roll. The single-faced corrugated fiberboard 102 is wrapped on the side surfaces of a stack 106 of planographic printing plates which are sealed by inner packaging paper and are stacked on a pallet 110 on a turntable 108A of a wrapping device 108. In such a packaging apparatus 100, it is difficult in light of the mechanisms of the wrapping device 108 to stop the wrapping operation carried out by the wrapping device 108, after the preceding single-faced corrugated fiberboard 102 is completely drawn out from the preceding single-faced corrugated fiberboard roll 102A, and join together, with a joining device, of the trailing end of the preceding single-faced corrugated fiberboard 102 and the leading end of a subsequent single-faced corrugated fiberboard 104. Therefore, when the length of the single-faced corrugated fiberboard 102 wound around the single-faced corrugated fiberboard roll 102A becomes shorter than the length needed to wrap around the stack 106, the single-faced corrugated fiber board 102 is cut by a cutter 104 and the trailing end of the preceding single-faced corrugated fiberboard 102 is joined to the leading end of the subsequent single-faced corrugated fiberboard 104. However, with this method, a significant amount of the single-faced corrugated fiberboard 102 is wasted without being used, which results in wasting resources. A conventional device has been conceived of, which connects the trailing end of a preceding packaging material with the leading end of a subsequent packaging material (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 5-97123). In this device disclosed in JP-A No. 5-97123, when the object to be packaged is small, the packaging material is reliably prevented from running out during the wrapping thereof. However, in this device, when the object to be packaged is large, there is a possibility that the packaging material runs out during wrapping and there arise problems similar to those of the packaging apparatus 100. SUMMARY OF THE INVENTION In view of the aforementioned, an object of the present invention is, when a preceding packaging material is to be replaced by a subsequent packaging material, to use up the preceding packaging material to the end thereof so that the packaging material is not wasted. In a first aspect of the present invention, a packaging apparatus comprises: a draw-out roller drawing-out a packaging material from a packaging material roll in which the packaging material is wound-up in a form of a roll; an accumulating roller around which the packaging material drawn out by the draw-out roller is trained; moving means for moving the accumulating roller at a time when the packaging material roll is to be replaced, and accumulating the packaging material at the accumulating roller; and a wrapping device for pulling-out the packaging material which is trained on the accumulating roller, and wrapping the packaging material around side surfaces of a loaded object which is loaded on a pallet. In the packaging apparatus based on this aspect, when the packaging material roll is to be replaced, the accumulating roller, on which the packaging material is trained, is moved by the moving means. The preceding packaging material, which has been drawn out from the packaging material roll by the draw-out roller, is accumulated at the accumulating roller. In this way, the preceding packaging material, which is drawn out at the time of replacing the packaging material roll, is accumulated at the accumulating roller without bending and without being scratched. In the packaging apparatus of the present aspect, the preceding packaging material is drawn out from the packaging material roll and is joined to the subsequent packaging material, and immediately thereafter, wrapping of the packaging material onto the side surfaces of the loaded object loaded on a pallet can be carried out by the wrapping device. Accordingly, the preceding packaging material can be used up to the end without waste. In a second aspect of the present invention, the accumulating roller of the packaging apparatus is provided so as to be oriented vertically. In the packaging apparatus based on the present aspect, the accumulating roller is provided so as to be oriented vertically, and the packaging material is trained around so as to be oriented vertically. Therefore, the packaging material, which is conveyed while oriented vertically, does not bend due to its own weight. In a third aspect of the present invention, the packaging apparatus further comprises control means for stopping the accumulating roller and the draw-out roller when, after stopping of the wrapping device, a preceding packaging material is drawn out from the packaging material roll by the draw-out roller while being accumulated at the accumulating roller and a trailing end of the preceding packaging material is drawn out to a joining position at which the trailing end of the preceding packaging material is joined together with a leading end of a subsequent packaging material. In the packaging apparatus based on the present aspect, after stopping of the wrapping device, the preceding packaging material is drawn out from the packaging material roll by the draw-out roller while being accumulated at the accumulating roller which is moving. Then, when the trailing end of the preceding packaging material is drawn out to the joining position at which the trailing end of the preceding packaging material is joined with the leading end of the subsequent packaging material, the accumulating roller and the draw-out roller are stopped by the control means. In this way, the trailing end of the preceding packaging material and the leading end of the subsequent packaging material can be joined together. Further, the preceding packaging material can be used up to the end without waste. In a fourth aspect of the present invention, a joining device, which joins together the trailing end of the preceding packaging material which has been drawn out and the leading end of the subsequent packaging material, is provided at the joining position. In accordance with the present aspect, the trailing end of the preceding packaging material and the leading end of the subsequent packaging material are joined together by the joining device at the joining position. Therefore, the packaging material can be supplied continuously. In a fifth aspect of the present invention, the packaging apparatus has, between the accumulating roller and the wrapping device, a tension applying roller for applying tension to the packaging material, and restraining means for restraining movement of the tension applying roller. In accordance with the present aspect, between the accumulating roller and the wrapping device, tension is applied to the packaging material by the tension applying roller. Therefore, wrinkles do not form in the packaging material at the time when the packaging material is wrapped around the loaded object at the wrapping device. Further, because movement of the tension applying roller is restrained by the restraining means, slack does not arise and wrinkles do not form when the packaging material is being accumulated at the accumulating roller. In a sixth aspect of the present invention, after a trailing end of a preceding packaging material and a leading end of a subsequent packaging material have been joined together, a control means releases restraining of a tension applying roller by a restraining means, and drives the wrapping device, and releases restraining of the accumulating roller by the moving means when the tension applying roller is moved past a predetermined position due to tension of the packaging material, and restrains the accumulating roller when the accumulating roller is moved to a predetermined position due to the packaging material, which has been accumulated, being drawn out. In accordance with the present aspect, after the trailing end of the preceding packaging material and the leading end of the subsequent packaging material have been joined together, the control means releases the restraining of the tension applying roller by the restraining means. Next, when the wrapping device is driven and the tension applying roller is moved past a predetermined position due to the tension of the packaging material, the restraining of the accumulating roller by the moving means is released by the control means. When the accumulating roller moves to a predetermined position due to the packaging material, which has been accumulated at the accumulating roller, being drawn out, movement of the accumulating roller is restrained by the control means. In this way, the accumulating roller and the tension applying roller are positioned in the state at the time of usual wrapping, and immediately thereafter, the subsequent packaging material can be wrapped on the side surfaces of the loaded object. In a seventh aspect of the present invention, a packaging method for drawing a packaging material out from a packaging material roll in which the packaging material is wound-up in a form of a roll, and wrapping the packaging material around side surfaces of a loaded object which is loaded on a pallet, comprises: when the packaging material roll is to be replaced, drawing a preceding packaging material out from the packaging material roll; and increasing an amount of the drawn-out packaging material accumulated on an accumulating roller on which the packaging material, which has been drawn out, is trained, by moving the accumulating roller. According to the present aspect, when the packaging material roll is to be replaced, the accumulating roller is moved such that an amount of the drawn-out preceding packaging material accumulated on an accumulating roller on which the packaging material, which has been drawn out, is trained is increased. The drawn-out packaging material can thereby be accumulated without bending or being scratched. Further, in accordance with the present aspect, the preceding packaging material is drawn out from the packaging material roll, and is joined to the subsequent packaging material, and immediately thereafter the packaging material can be wrapped around the side surfaces of the loaded object which is loaded on a pallet. Therefore, the preceding packaging material can be used without waste. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a packaging apparatus relating to an embodiment of the present invention. FIG. 2 is a perspective view showing a stack around whose side surfaces a single-faced corrugated fiberboard is wrapped by the packaging apparatus relating to the embodiment. FIG. 3 is a schematic diagram showing a reserve mechanism of the packaging apparatus relating to the embodiment. FIG. 4 is a block diagram showing a control device of the packaging apparatus relating to the embodiment. FIG. 5 is a schematic diagram showing the packaging apparatus relating to the embodiment. FIG. 6 is another schematic diagram showing the packaging apparatus relating to the embodiment. FIG. 7 is a schematic diagram showing the packaging apparatus relating to the embodiment. FIG. 8 is a perspective view showing the stack around whose side surfaces the single-faced corrugated fiberboard is wrapped by the packaging apparatus relating to the embodiment. FIG. 9 is a schematic diagram showing a packaging apparatus relating to a conventional example. DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described hereinafter with reference to the drawings. As shown in FIG. 1, in a packaging apparatus 10 relating to the present embodiment, a single-faced corrugated fiberboard 1 is drawn out from a single-faced corrugated fiberboard roll 3, or a single-faced corrugated fiberboard 2 is drawn out from a single-faced corrugated fiberboard roll 4, and is wrapped around the side surfaces of a stack 13 set on a pallet 11. (The single-faced corrugated fiberboard 1 or 2 is wound around once or twice.) The side surfaces of the stack 13 are protected thereby. As shown in FIG. 2, the stack 13 is formed by a bundle of plural planographic printing plates being placed on a plate 17 which is formed of vinyl chloride and sealed by an inner packaging paper 15, and is and set on the pallet 11. In order to protect the stack 13 from moisture and to shield the stack 13 from the light and the like, kraft paper in which aluminum foils are adhered together by polyethylene, kraft paper in which nylon or PET on which aluminum is vapor-deposited are adhered together by polyethylene, black polyethylene film in which carbon is mixed in, or the like can be used for the inner packaging paper 15. As shown in FIG. 1, the packaging apparatus 10 has a wrapping device 12 which pulls the preceding single-faced corrugated fiberboard 1 out from the single-faced corrugated fiber board roll 3, and wraps it around the side surfaces of the stack 13. Here, explanation will be given by using the single-faced corrugated fiberboard 1 as an example, but the single-faced corrugated fiberboard 2 is wrapped in the same way. A circular turntable 14 is provided at the wrapping device 12. The pallet 11 on which the stack 13 is loaded is set on the turntable 14, and the turntable 14 is turned clockwise (in the direction of arrow A in the drawing) by an unillustrated turning device. A first leading end holding device 16, which holds the leading end of the single-faced corrugated fiberboard 1, stands erect on the turntable 14 with a gap between the first leading end holding device 16 and the side surface of the stack 13. The first leading end holding device 16 is a chamber which is shaped as a rectangular column and is hollow. The interior of the first leading end holding device 16 is made to be a vacuum by an unillustrated vacuum device. A large number of suction holes (not shown) are formed in the surface of the first leading end holding device 16 which surface faces the side surface of the stack 13. In this way, the leading end of the single-faced corrugated fiberboard 1 can be sucked, and when the turntable 14 is turned, the single-faced corrugated fiberboard 1 is drawn out from the single-faced corrugated fiberboard roll 3 and wrapped around the side surfaces of the stack 13. A slack removing device 18 is provided which, when the turntable 14 is turned, makes the single-faced corrugated fiberboard 1 fit tightly to the side surfaces of the stack 13, so as to remove the slack in the wrapped single-faced corrugated fiberboard 1. The slack removing device 18 is structured by a slack removing roller 22 and a U-shaped arm 24 which rotatably supports the both axial direction end portions of the slack removing roller 22. Shaft portions 24B, which are rotatably supported by bearings provided at the outer side of the turntable 14, are formed at the both end portions of a base shaft 24A of the arm 24. The arm 24 swings around the shaft portions 24B due to an unillustrated air cylinder, and presses the slack removing roller 22 against the side surface of the stack 13. When the turntable 14 is turned one time and the single-faced corrugated fiberboard 1 is wrapped one time around the side surfaces of the stack 13, a second leading end holding device 28 holds the single-faced corrugated fiberboard 1. Here, a cutting-joining device 26 cuts the single-faced corrugated fiberboard 1, and adheres it to the side surface of the stack 13 by an adhesive material such as tape, a hot melt adhesive, or the like. Further, as shown in FIG. 5, when the wrapping device 12 is stopped, the second leading end holding device 28 holds the leading end of the single-faced corrugated fiberboard 1 (as shown by the chain line in the figure), and when turning of the wrapping device 12 starts, the second leading end holding device 28 transfers the leading end of the single-faced corrugated fiberboard 1 to the first leading end holding device 16. Note that, in the same way as the first leading end holding device 16, the second leading end holding device 28 is a vacuum chamber which is shaped as a rectangular column, and sucks and holds the leading end of the single-faced corrugated fiberboard 1. Next, a supplying mechanism 30, which conveys the single-faced corrugated fiberboard 1 from the single-faced corrugated fiberboard roll 3 to the wrapping device 12 in a state in which the single-faced corrugated fiberboard 1 is oriented vertically, will be described. As shown in FIG. 1, a draw-out shaft 32 and a draw-out shaft 34, at which the single-faced corrugated fiberboard rolls 3, 4 are installed, are provided so as to be oriented vertically in the supplying mechanism 30. The peripheral surfaces of the draw-out shaft 32 and the draw-out shaft 34 are subjected to powder braking processing, such that the cores slide and the drawn-out single-faced corrugated fiberboards 1, 2 do not go slack. A guide roller 36, which guides the single-faced corrugated fiberboard 1, and a guide roller 38, which guides the single-faced corrugated fiberboard 2, are provided so as to be oriented vertically and so as to face one another, at the downstream side of the draw-out shaft 32 and the draw-out shaft 34. Further, draw-out rollers 40, which are driven by an unillustrated motor and which nip the single-faced corrugated fiberboards 1, 2 and draw them out from the single-faced corrugated fiberboard rolls 3, 4, are provided so as to be oriented vertically at the downstream side of the guide rollers 36, 38. A joining device 39, which joins the single-faced corrugated fiberboard 1 and the single-faced corrugated fiberboard 2 by tape or an adhesive, is disposed between the draw-out rollers 40 and the guide rollers 36, 38. A reserve mechanism 42, which will be described later and at which the single-faced corrugated fiberboard 1 is accumulated, is provided at the downstream side of the draw-out rollers 40. (Hereinafter, explanation will be given by using the single-faced corrugated fiberboard 1 as an example.) A dancer roller 44 serving as a tension applying mechanism 48 is disposed between two path rollers 67 at the downstream side of the reserve mechanism 42. A supporting plate 69, which pivotally supports the dancer roller 44, is supported at an air cylinder 46, and applies tension to the single-faced corrugated fiberboard 1 by adjusting the air pressure. Further, a holding brake 72, which restrains movement of the rod of the air cylinder 46, is provided at the tension applying mechanism 48. The reserve mechanism 42 will now be described. As shown in FIGS. 1 and 5, both axial direction end portions of a pair of reserve rollers 52 of the reserve mechanism 42, which is provided between path rollers 59, are connected by connecting plates 54 so as to be freely rotatable. As shown in FIG. 3, the connecting plates 54 are supported, so as to be movable in the direction of arrow B, by rails 58 disposed above and below. A sprocket 60 is rotatably mounted to a mounting plate (not illustrated) on an imaginary extension of the rail 58. One end portion of a timing belt 64, which meshes with the teeth of the sprocket 60, is attached to the connecting plate 54. A weight 66 is attached to the other end portion of the timing belt 64. An electromagnetic brake 68, which stops rotation of the sprocket 60 or allows the sprocket 60 to rotate freely, is provided. When the electromagnetic brake 68 is released by a control device 70 (see FIG. 4), the sprocket 60 becomes able to rotate, the weight 66 drops due to its own weight, the connecting plate 54 is pulled by the timing belt 64 and moves in the direction of arrow B, and the single-faced corrugated fiberboard 1 accumulates between a fixed roller 56 and the reserve rollers 52. Here, explanation will be given of the flow from the time that wrapping by the preceding single-faced corrugated fiberboard 1 is carried out to the time of switching to wrapping by the subsequent single-faced corrugated fiberboard 2. First, as shown in FIG. 5, the turntable 14 is turned by the control device 70 (see FIG. 4) in the state in which the leading end of the preceding single-faced corrugated fiberboard 1 is held by the first leading end holding device 16. In this way, the single-faced corrugated fiberboard 1 is pulled out from the single-faced corrugated fiberboard roll 3, and is wrapped on the side surfaces of the stack 13. Then, when the single-faced corrugated fiberboard 1 has been wrapped one time around the side surfaces of the stack 13, the cutting-joining device 26 is operated by the control device 70 (see FIG. 4). In this way, the single-faced corrugated fiberboard 1 is held by the second leading end holding device 28 and is cut, and this end portion is joined by tape or an adhesive to the leading end held at the first leading end holding device. At this time, the air cylinder 46 pushes the dancer roller 44 to contact the single-faced corrugated fiberboard 1, and applies tension to the single-faced corrugated fiberboard 1. The single-faced corrugated fiberboard 1 is thereby wrapped around the side surfaces of the stack 13 without going slack. Note that the rotating speed of the draw-out rollers 40 which feed the single-faced corrugated fiberboard 1 out is adjusted such that the dancer roller 44 is positioned at a predetermined position due to the reaction force received from the single-faced corrugated fiberboard 1. The electromagnetic brake 68 is operated by the control device 70 (see FIG. 4), and restrains movement of the reserve rollers 52 at positions near the fixed roller 56. In place of the stack 13 around which the single-faced corrugated fiberboard 1 has been wrapped, a stack 13 around which the single-faced corrugated fiberboard 1 has not yet been wrapped is set on the turntable 14, and in the same way, the single-faced corrugated fiberboard 1 is wrapped around the side surfaces of this stack 13. When this is repeated and the remaining length of the single-faced corrugated fiberboard 1 is less than the length needed to be wrapped around the side surfaces of the stack 13, as shown in FIG. 6, first, the holding brake 72 operates so as to stop the air cylinder 46 at a predetermined position and restrain the dancer roller 44. Then, by the control device 70 (see FIG. 4), the draw-out rollers 40 are driven and the electromagnetic brake 68 is released. In this way, the single-faced corrugated fiberboard 1 is drawn out from the single-faced corrugated fiberboard roll 3 by the draw-out rollers 40, and the reserve rollers 52 are moved in the direction of moving away from the fixed roller 56 (the direction of arrow B in the drawing) due to the weight of the weight 66. At this time, because the single-faced corrugated fiberboard 1 which is drawn out is accumulated in a state of being trained around the reserve rollers 52, the single-faced corrugated fiberboard 1 does not fold over due to its own weight, and is not damaged. Note that an air cylinder may be employed in place of the weight 66. Then, the trailing end of the drawn-out single-faced corrugated fiberboard 1 is detected by a sensor 74. When the trailing end of the single-faced corrugated fiberboard 1 is drawn out to the position of the joining device 39, the control device 70 (see FIG. 4), on the basis of the detection signal of the sensor 74, stops the driving of the draw-out rollers 40, and operates the electromagnetic brake 68 so as to restrain the reserve rollers 52. Then, the joining device 39 is driven by the control device 70 (see FIG. 4), such that the leading end of the subsequent single-faced corrugated fiberboard 2, which is drawn out to the position of the joining device 39, and the trailing end of the preceding single-faced corrugated fiberboard 1 are joined together. Then, after the trailing end of the preceding single-faced corrugated fiberboard 1 and the leading end of the subsequent single-faced corrugated fiberboard 2 have been joined together, as shown in FIG. 7, by the control device 70 (see FIG. 4), the turntable 14 is rotated, and the air cylinder 46 is operated such that restraining of the dancer roller 44 is cancelled. Further, the draw-out rollers 40 are driven. The dancer roller 44 is moved, by the tension of the single-faced corrugated fiberboard 1, in the direction resisting the urging force of the air cylinder 46 (i.e., in the direction of arrow D in the drawing). Then, when the dancer roller 44 has moved to the predetermined position illustrated by the solid line in the drawing, the electromagnetic brake 68 is released by the control device 70 (see FIG. 4). Here, the tension which the dancer roller 44 applies to the single-faced corrugated fiberboard 1 is greater than the tension which is applied to the single-faced corrugated fiberboard 1 due to the reserve rollers 52 being pulled by the weight 66. Therefore, due to the tension of the single-faced corrugated fiberboard 1, the reserve rollers 52 move in the direction of approaching the fixed roller 56 (the direction of arrow E in the drawing) against the tension of the weight 66. Then, when the reserve rollers 52 have moved to the predetermined positions shown by the solid lines in the drawing, the electromagnetic brake 68 is operated by the control device 70 (see FIG. 4), and movement of the reserve rollers 52 is restrained. The reserve rollers 52 and the dancer roller 44 thereby return to their states at the time of usual wrapping. Therefore, wrapping of the stack 13 by the single-faced corrugated fiberboard 2 can be carried out immediately thereafter. In this way, at the time when the single-faced corrugated fiberboard roll 3 is replaced by the single-faced corrugated fiberboard roll 4, the preceding single-faced corrugated fiberboard 1 is drawn out to its trailing end from the single-faced corrugated fiberboard roll 3, and the reserve rollers 52 are moved so as to accumulate the drawn-out single-faced corrugated fiberboard 1 at the reserve rollers 52. Therefore, the preceding single-faced corrugated fiberboard 1 can be used up to the end thereof without any remaining, and there is no waste of the single-faced corrugated fiberboard 1. Further, the drawn-out single-faced corrugated fiberboard 1 does not fold over or become damaged. Thereafter, as shown in FIG. 8, a top plate 76 is placed on the top surface of the stack 13 around which the single-faced corrugated fiberboards 1, 2 are wrapped, and the top plate 76 is bound by binding bands 78, and this bound structure is shipped out. Note that, in the present embodiment, a packaging apparatus, which wraps a single-faced corrugated fiberboard around the side surfaces of stacked planographic printing plates, is described as an example. However, the present invention is not limited to the same, and can be applied to various other types of loaded objects. Because the present invention is structured as described above, the trailing end of a preceding packaging material and the leading end of a subsequent packaging material can be easily joined together, and the preceding packaging material can be used up until the end thereof. Therefore, there is no waste of the preceding packaging material. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a packaging apparatus and a packaging method for wrapping a packaging material around side surfaces of a loaded object which is loaded on a pallet. 2. Description of the Related Art As shown in FIG. 9 , in a conventional packaging apparatus 100 for planographic printing plates, a single-faced corrugated fiberboard 102 is drawn out by nip rollers 112 from a single-faced corrugated fiberboard roll 102 A which is wound up in the shape of a roll. The single-faced corrugated fiberboard 102 is wrapped on the side surfaces of a stack 106 of planographic printing plates which are sealed by inner packaging paper and are stacked on a pallet 110 on a turntable 108 A of a wrapping device 108 . In such a packaging apparatus 100 , it is difficult in light of the mechanisms of the wrapping device 108 to stop the wrapping operation carried out by the wrapping device 108 , after the preceding single-faced corrugated fiberboard 102 is completely drawn out from the preceding single-faced corrugated fiberboard roll 102 A, and join together, with a joining device, of the trailing end of the preceding single-faced corrugated fiberboard 102 and the leading end of a subsequent single-faced corrugated fiberboard 104 . Therefore, when the length of the single-faced corrugated fiberboard 102 wound around the single-faced corrugated fiberboard roll 102 A becomes shorter than the length needed to wrap around the stack 106 , the single-faced corrugated fiber board 102 is cut by a cutter 104 and the trailing end of the preceding single-faced corrugated fiberboard 102 is joined to the leading end of the subsequent single-faced corrugated fiberboard 104 . However, with this method, a significant amount of the single-faced corrugated fiberboard 102 is wasted without being used, which results in wasting resources. A conventional device has been conceived of, which connects the trailing end of a preceding packaging material with the leading end of a subsequent packaging material (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 5-97123). In this device disclosed in JP-A No. 5-97123, when the object to be packaged is small, the packaging material is reliably prevented from running out during the wrapping thereof. However, in this device, when the object to be packaged is large, there is a possibility that the packaging material runs out during wrapping and there arise problems similar to those of the packaging apparatus 100 . | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the aforementioned, an object of the present invention is, when a preceding packaging material is to be replaced by a subsequent packaging material, to use up the preceding packaging material to the end thereof so that the packaging material is not wasted. In a first aspect of the present invention, a packaging apparatus comprises: a draw-out roller drawing-out a packaging material from a packaging material roll in which the packaging material is wound-up in a form of a roll; an accumulating roller around which the packaging material drawn out by the draw-out roller is trained; moving means for moving the accumulating roller at a time when the packaging material roll is to be replaced, and accumulating the packaging material at the accumulating roller; and a wrapping device for pulling-out the packaging material which is trained on the accumulating roller, and wrapping the packaging material around side surfaces of a loaded object which is loaded on a pallet. In the packaging apparatus based on this aspect, when the packaging material roll is to be replaced, the accumulating roller, on which the packaging material is trained, is moved by the moving means. The preceding packaging material, which has been drawn out from the packaging material roll by the draw-out roller, is accumulated at the accumulating roller. In this way, the preceding packaging material, which is drawn out at the time of replacing the packaging material roll, is accumulated at the accumulating roller without bending and without being scratched. In the packaging apparatus of the present aspect, the preceding packaging material is drawn out from the packaging material roll and is joined to the subsequent packaging material, and immediately thereafter, wrapping of the packaging material onto the side surfaces of the loaded object loaded on a pallet can be carried out by the wrapping device. Accordingly, the preceding packaging material can be used up to the end without waste. In a second aspect of the present invention, the accumulating roller of the packaging apparatus is provided so as to be oriented vertically. In the packaging apparatus based on the present aspect, the accumulating roller is provided so as to be oriented vertically, and the packaging material is trained around so as to be oriented vertically. Therefore, the packaging material, which is conveyed while oriented vertically, does not bend due to its own weight. In a third aspect of the present invention, the packaging apparatus further comprises control means for stopping the accumulating roller and the draw-out roller when, after stopping of the wrapping device, a preceding packaging material is drawn out from the packaging material roll by the draw-out roller while being accumulated at the accumulating roller and a trailing end of the preceding packaging material is drawn out to a joining position at which the trailing end of the preceding packaging material is joined together with a leading end of a subsequent packaging material. In the packaging apparatus based on the present aspect, after stopping of the wrapping device, the preceding packaging material is drawn out from the packaging material roll by the draw-out roller while being accumulated at the accumulating roller which is moving. Then, when the trailing end of the preceding packaging material is drawn out to the joining position at which the trailing end of the preceding packaging material is joined with the leading end of the subsequent packaging material, the accumulating roller and the draw-out roller are stopped by the control means. In this way, the trailing end of the preceding packaging material and the leading end of the subsequent packaging material can be joined together. Further, the preceding packaging material can be used up to the end without waste. In a fourth aspect of the present invention, a joining device, which joins together the trailing end of the preceding packaging material which has been drawn out and the leading end of the subsequent packaging material, is provided at the joining position. In accordance with the present aspect, the trailing end of the preceding packaging material and the leading end of the subsequent packaging material are joined together by the joining device at the joining position. Therefore, the packaging material can be supplied continuously. In a fifth aspect of the present invention, the packaging apparatus has, between the accumulating roller and the wrapping device, a tension applying roller for applying tension to the packaging material, and restraining means for restraining movement of the tension applying roller. In accordance with the present aspect, between the accumulating roller and the wrapping device, tension is applied to the packaging material by the tension applying roller. Therefore, wrinkles do not form in the packaging material at the time when the packaging material is wrapped around the loaded object at the wrapping device. Further, because movement of the tension applying roller is restrained by the restraining means, slack does not arise and wrinkles do not form when the packaging material is being accumulated at the accumulating roller. In a sixth aspect of the present invention, after a trailing end of a preceding packaging material and a leading end of a subsequent packaging material have been joined together, a control means releases restraining of a tension applying roller by a restraining means, and drives the wrapping device, and releases restraining of the accumulating roller by the moving means when the tension applying roller is moved past a predetermined position due to tension of the packaging material, and restrains the accumulating roller when the accumulating roller is moved to a predetermined position due to the packaging material, which has been accumulated, being drawn out. In accordance with the present aspect, after the trailing end of the preceding packaging material and the leading end of the subsequent packaging material have been joined together, the control means releases the restraining of the tension applying roller by the restraining means. Next, when the wrapping device is driven and the tension applying roller is moved past a predetermined position due to the tension of the packaging material, the restraining of the accumulating roller by the moving means is released by the control means. When the accumulating roller moves to a predetermined position due to the packaging material, which has been accumulated at the accumulating roller, being drawn out, movement of the accumulating roller is restrained by the control means. In this way, the accumulating roller and the tension applying roller are positioned in the state at the time of usual wrapping, and immediately thereafter, the subsequent packaging material can be wrapped on the side surfaces of the loaded object. In a seventh aspect of the present invention, a packaging method for drawing a packaging material out from a packaging material roll in which the packaging material is wound-up in a form of a roll, and wrapping the packaging material around side surfaces of a loaded object which is loaded on a pallet, comprises: when the packaging material roll is to be replaced, drawing a preceding packaging material out from the packaging material roll; and increasing an amount of the drawn-out packaging material accumulated on an accumulating roller on which the packaging material, which has been drawn out, is trained, by moving the accumulating roller. According to the present aspect, when the packaging material roll is to be replaced, the accumulating roller is moved such that an amount of the drawn-out preceding packaging material accumulated on an accumulating roller on which the packaging material, which has been drawn out, is trained is increased. The drawn-out packaging material can thereby be accumulated without bending or being scratched. Further, in accordance with the present aspect, the preceding packaging material is drawn out from the packaging material roll, and is joined to the subsequent packaging material, and immediately thereafter the packaging material can be wrapped around the side surfaces of the loaded object which is loaded on a pallet. Therefore, the preceding packaging material can be used without waste. | 20040715 | 20060926 | 20050120 | 96555.0 | 0 | GERRITY, STEPHEN FRANCIS | METHOD OF WRAPPING INCLUDING JOINING OF TRAILING END OF WRAPPING MATERIAL TO LEADING END OF SUBSEQUENT WRAPPING MATERIAL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,891,423 | ACCEPTED | Wide-band speech signal compression and decompression apparatus, and method thereof | An apparatus to compress a wide-band speech signal, the apparatus including a narrow-band speech compressor to compress a low-band speech signal of the wide-band speech signal and output the compressed low-band speech signal as a low-band speech packet; and a high-band speech compressor to compress a high-band speech signal of the wide-band speech signal using energy information of the low-band speech signal provided from the narrow-band speech compressor, and outputs the compressed high-band speech signal as a high-band speech packet. | 1. An apparatus to compress a wide-band speech signal, the apparatus comprising: a narrow-band speech compressor to compress a low-band speech signal of the wide-band speech signal and output the compressed low-band speech signal as a low-band speech packet; and a high-band speech compressor to compress a high-band speech signal of the wide-band speech signal using energy information of the low-band speech signal provided from the narrow-band speech compressor, and output the compressed high-band speech signal as a high-band speech packet. 2. The apparatus of claim 1, wherein the energy information of the low-band speech signal is quantized fixed codebook gains of the narrow-band speech compressor, corresponding to a frame of the high-band speech compressor, in response to the narrow band speech compressor being a CELP type compressor. 3. The apparatus of claim 1, wherein the energy information of the low-band speech signal is an average value of quantized fixed codebook gains of the narrow-band speech compressor, corresponding to a frame of the high-band speech compressor, in response to the narrow band speech compressor being a CELP type compressor. 4. The apparatus of claim 1, wherein the high-band speech signal compressor comprises: a filter bank to split the high-band speech signal of the wide-band speech signal into a plurality of band signals with different frequency bands; an RMS calculator to calculate RMS values for each of the band signals transmitted from the filter bank; a band priority decision unit to determine priorities of the band signals split by the filter bank based on the RMS values calculated by the RMS calculator; a band signal quantization module to quantize the band signals split by the filter bank and output a quantization index for each of the bands using band priority information determined by the band priority decision unit and the energy information of the low-band speech signal; and a packetizer to packetize the band priority information and the quantization index for each band output from the band signal quantization module and output the packetized result as the high-band speech packet. 5. The apparatus of claim 4, wherein the band priority decision unit determines the priorities of the band signals according to magnitudes of the RMS values. 6. The apparatus of claim 4, wherein the band priority decision unit assigns a higher priorities to the band signals with greater RMS values. 7. The apparatus of claim 4, wherein the band signal quantization module comprises: a first DCT calculator to performs a first Discrete Cosine Transform (DCT) on the plurality of band signals provided from the filter bank and obtain first DCT coefficients; a magnitude extractor to extract magnitudes of the first DCT coefficients; a sign extractor to extract signs of the first DCT coefficients; a second DCT calculator to perform a second DCT on the magnitudes of the first DCT coefficients extracted from the magnitude extractor and obtain second DCT coefficients; a DC divider to divide the second DCT coefficients into DC components and DCT coefficients excluding the DC components and output the DCT coefficients excluding the DC components as third DCT coefficients; a DC quantization module to quantize the DC components divided by the DC divider; an RMS value calculator to calculate and output RMS values of the third DCT coefficients; an RMS value quantization module to quantize the RMS values output by the RMS value calculator; a normalizer to normalize the third DCT coefficients based on quantized RMS values computed using RMS value quantization indexes output from the RMS value quantization module; a DCT coefficient quantizer to quantize the normalized third DCT coefficients; and a sign quantization module to quantize the signs of the first DCT coefficients extracted by the sign extractor. 8. The apparatus of claim 7, wherein the DC quantization module quantizes the DC components by inter-band prediction using the energy information of the low-band speech signal and the DC components of each of the band signals. 9. The apparatus of claim 7, wherein the DC quantization module comprises: an inter-band predictor unit to perform inter-band prediction using the energy information of the low-band speech signal and the DC components of each of the band signals; a DC quantizer to quantize DC prediction errors output from the inter-band predictor unit and output DC quantization indexes; and a DC dequantizer to obtain the DC prediction errors quantized for each of the band signals from the DC quantization indexes output from the DC quantizer, and obtain DC values quantized for each of the band signals from the DC prediction errors. 10. The apparatus of claim 9, wherein the inter-band predictor unit obtains the DC prediction errors using the equations: Δ0=D0−Gĝc Δi=Di−G{circumflex over (D)}i−1 i=1, 2, 3 . . . wherein Di is a log DC value of an i-th band of high-band speech signal, {circumflex over (D)}i is a quantized log DC value of the i-th band of high-band speech signal, ĝc is a quantized log energy value of a low-band signal, G is a prediction coefficient in the inter-band predictor unit, and Δi is a DC prediction error of the i-th band of the high-band speech signal. 11. The apparatus of claim 9, wherein the DC quantization module scalar-quantizes the DC prediction errors independently. 12. The apparatus of claim 7, wherein the RMS value quantization module quantizes the RMS values of the third DCT coefficients by intra-band prediction using the quantized DC values of the second DCT coefficients. 13. The apparatus of claim 7, wherein the RMS quantization module comprises: an intra-band predictor unit to perform intra-band prediction using the RMS values of the third DCT coefficients and the quantized DC values of the second DCT coefficients; and a RMS quantizer to quantize RMS prediction errors obtained by the intra-band predictor unit. 14. The apparatus of claim 13, wherein the intra-band predictor unit obtains the intra-band RMS prediction errors using the equation: δi=si−G{circumflex over (D)}i i=0, 1, 2, 3, . . . wherein, si is a log RMS value of the third DCT coefficient at an i-th band of high-band speech signal, {circumflex over (D)}i is a quantized log DC value of the second DCT coefficient at the i-th band of the high-band speech signal, G is a prediction coefficient of the intra-band predictor unit, and δi is an intra-band RMS prediction error value at the i-th band of the high-band speech signal. 15. The apparatus of claim 7, wherein the DCT coefficient quantizer quantizes a predetermined number of the third DCT coefficients for each of the band signals and removes the remaining third DCT coefficients. 16. The apparatus of claim 15, wherein the predetermined number is higher at a band with a higher priority, and the predetermined number is lower at a band with a lower priority, according to the band priority information. 17. The apparatus of claim 7, wherein the DCT coefficient quantizer determines indexes corresponding to a range of the third DCT coefficients to be quantized at each band according to the band priority information, and quantizes the third DCT coefficients for each band with reference to the determined indexes. 18. The apparatus of claim 7, wherein the DCT coefficient quantizer determines indexes corresponding to a range of the third DCT coefficients to be quantized at each band according to the band priority information, removes the third DCT coefficients lower than the determined indexes of the third DCT coefficients, and quantizes the remaining third DCT coefficients. 19. The apparatus of claim 7, wherein the DCT coefficient quantizer performs quantization using a split vector quantization method, which splits the third DCT coefficients to be quantized at each band into a plurality of subvectors, and selects subvectors to be quantized and subvectors to be removed among the plurality of subvectors. 20. The apparatus of claim 7, wherein the sign quantization module detects magnitude order information of the first DCT coefficients using quantized indexes of the third DCT coefficients and DC quantization indexes of the second DCT coefficients, and quantizes the signs of the first DCT coefficients according to the magnitude order information of the first DCT coefficients. 21. The apparatus of claim 20, wherein the sign quantization module divides signs of the first DCT coefficients into signs of the first DCT coefficients to be quantized and signs of the first DCT coefficients to be removed, and quantizes signs of the first DCT coefficients to be quantized using the magnitude order information of the first DCT coefficients. 22. The apparatus of claim 21, wherein the signs of the first DCT coefficients to be quantized comprise a predetermined number of the signs of the first DCT coefficients in a descending order starting from a first DCT coefficient with a maximum magnitude. 23. The apparatus of claim 7, wherein the sign quantization module comprises: a DCT coefficient dequantizer to obtain dequantized third DCT coefficients from quantized indexes of the third DCT coefficients; a DC dequantizer to obtain dequantized DC values of the second DCT coefficients from DC quantized indexes of the second DCT coefficients; an inverse DCT calculator to perform an inverse DCT on the dequantized third DCT coefficients and the dequantized DC values of the second DCT coefficients; an arrangement unit to arrange magnitudes of quantized first DCT coefficients output from the inverse DCT calculator in a descending order of the magnitudes; and a sign quantizer to quantize signs of the first DCT coefficients according to magnitude order information of the quantized first DCT coefficients output from the arrangement unit. 24. The apparatus of claim 23, wherein the sign quantizer quantizes signs corresponding to a predetermined number of the first DCT coefficients in the descending order starting from a first DCT coefficient with a maximum magnitude on the basis of the magnitude order information of the quantized first DCT coefficients output from the arrangement unit, and removes the signs of the remaining quantized first DCT coefficients. 25. The apparatus of claim 1, further comprising a first band conversion unit to convert the wide-band speech signal into a low-band speech signal of a narrow-band and provide the low-band speech signal of the narrow-band to the narrow-band speech compressor. 26. An apparatus to decompress a wide-band speech signal, the wide-band speech signal including a compressed-low-band speech packet and a compressed high-band speech packet, the apparatus comprising: a narrow-band speech decompressor to decompress the compressed low-band speech packet into a low-band speech signal; a high-band speech decompressor to decompress the compressed high-band speech packet into a high-band speech signal using energy information of the decompressed low-band speech signal provided from the narrow-band speech decompressor; and an adder to add the low-band speech signal output from the narrow-band speech decompressor with the high-band speech signal output from the high-band speech decompressor and output the decompressed wide-band speech signal. 27. The apparatus of claim 26, wherein the high-band speech decompressor comprises: an inverse packetizer to split the high-band speech packet according to modules included in the apparatus; a sign dequantizer to dequantize signs output from the inverse packetizer; an inverse DCT calculation module to perform dequantizations respectively with reference to band priority information, third DCT quantization indexes, DC quantization indexes of second DCT coefficients, and RMS quantization indexes of third DCT coefficients, which are output from the inverse packetizer, to obtain quantized second DCT coefficients, and obtain magnitudes of quantized first DCT coefficients from the quantized second DCT coefficients; an arrangement unit to arrange magnitudes of the quantized first DCT coefficients output from the inverse DCT calculation module in descending order and output magnitude order information of the quantized first DCT coefficients; a sign insertion unit to insert signs of the first DCT coefficients obtained from the high-band speech packet to the magnitudes of the first DCT coefficients, based on the magnitude order information of the first DCT coefficients; a sign predictor module to predict signs which were not transmitted based on the magnitude order information of the first DCT coefficients provided from the arrangement unit, and inserts the predicted signs to the corresponding first DCT coefficient magnitudes; an inverse DCT calculator to convert the sign-inserted first DCT coefficients output from the sign insertion unit and the sign predictor module into quantized time-domain signals, according to each of a plurality of bands; and a decompressor to obtain speech signals for each of the bands using the quantized time-domain signals for each of the bands output from the inverse DCT calculator, and decompress the high-band speech signals using the speech signals for each of the bands. 28. The apparatus of claim 27, wherein the sign insertion unit inserts a predetermined number of the signs of the first DCT coefficients to the quantized first DCT coefficients in the descending order starting from a first quantized DCT coefficient with a maximal magnitude, using the magnitude order information of the first quantized DCT coefficients. 29. The apparatus of claim 27, wherein the sign predictor module predicts signs of first DCT coefficients which were not inserted by the sign insertion unit, and inserts the predicted signs to the corresponding first DCT coefficients. 30. The apparatus of claim 27, wherein the sign predictor module comprises: a plurality of time-domain converters to insert a positive sign and a negative sign respectively to each of indexes of first DCT coefficients of which signs were not inserted, and output time-domain information for respective signs of respective coefficient indexes using an inverse DCT; a signal predictor unit to output time-domain prediction information in a present frame for each of the indexes of the DCT coefficients of which signs were not inserted, using high-band signal information in a previous frame for each of indexes of the first DCT coefficients; and a sign selector that compares time-domain information obtained using the positive sign and the negative sign of the each of indexes of the DCT coefficients, with the time-domain prediction information, and determines a final sign for the each of indexes of the DCT coefficients. 31. The apparatus of claim 30, wherein the plurality of time-domain converters obtain a time-domain signal for each sign using the equations: p m + [ n ] [ k ] = c ^ m [ k ] cos ( π k ( 2 n + 1 ) 2 L ) p m - [ n ] [ k ] = - c ^ m [ k ] cos ( π k ( 2 n + 1 ) 2 L ) , and output values obtained by substituting n=O into the above equations, wherein Pm+[n][k] and pm−[n][k] represent sample values at a time index n for a first DCT coefficient index k in a present frame m, respectively, and |ĉm[k]| is a magnitude of a first quantized DCT coefficient in a present frame m. 32. The apparatus of claim 30, wherein the plurality of time-domain converters output a gradient at n=O by differentiating the following equation with respect to n and substituting n=O to an equation: p m + [ n ] [ k ] = c ^ m [ k ] cos ( π k ( 2 n + 1 ) 2 L ) p m - [ n ] [ k ] = - c ^ m [ k ] cos ( π k ( 2 n + 1 ) 2 L ) , wherein pm+[n][k] and pm−[n][k] represent sample values at a time index n for a first DCT coefficient index k in a present frame m, respectively, and |ĉm[k]| is a magnitude of a first quantized DCT coefficient. 33. The apparatus of claim 30, wherein the signal predictor unit outputs prediction information by predicting a time-domain signal in a present frame from DCT coefficients in a previous frame for each of the DCT coefficients using the following equation and substituting n=0 into the following equation: p ^ m [ n ] [ k ] = p m - 1 [ n + L ] [ k ] = c ^ m - 1 [ k ] cos ( π k ( 2 ( n + L ) + 1 ) 2 L ) , wherein {circumflex over (p)}m[n][k] is a time-domain prediction signal for a DCT coefficient index k, pm−1[n+L][k] is a signal corresponding to a time index n+L in a previous frame m−1, and ĉm−1[k] is a first quantized DCT coefficient in the previous frame. 34. The apparatus of claim 30, wherein the signal predictor unit outputs a predicted gradient at n=0 by differentiating the following equation with respect to n and substituting n=0 into the equation: p ^ m [ n ] [ k ] = p m - 1 [ n + L ] [ k ] = c ^ m - 1 [ k ] cos ( π k ( 2 ( n + L ) + 1 ) 2 L ) , wherein {circumflex over (p)}m[n][k] is a time-domain prediction signal for a first DCT coefficient index k, pm−1[n+L][k] is a signal corresponding to a time index n+L in a previous frame m−1, and ĉm−1[k] is a first quantized DCT coefficient in the previous frame. 35. The apparatus of claim 30, wherein the sign selector selects a sign nearest to the time-domain prediction information output from the signal predictor unit as a final sign. 36. A method of compressing a wide-band speech signal, the method comprising: receiving the wide-band speech signal and compressing a high-band speech signal of the wide-band speech signal using energy of a low-band signal of the wide-band speech signal; and outputting the compressed high-band speech signal as a high-band speech packet. 37. The method of claim 36, wherein the energy of the low-band signal is generated by narrow-band speech compressing of the low-band signal of the wide-band speech signal. 38. The method of claim 36, wherein the compressing of the high-band speech signal comprises: splitting the high-band speech signal of the wide-band speech signal into a plurality of band signals with different frequency bands; determining a priority for the plurality of band signals; and quantizing the plurality of band signals according to the determined priority. 39. The method of claim 38, wherein the determination of the priority is based on RMS values for the plurality of band signals. 40. The method of claim 39, wherein the determination of the priority is performed so that a higher priority is assigned to a band with a greater value of the RMS values. 41. The method of claim 38, wherein the quantizing of each band comprises: applying DCT to each of the plurality of band signals and obtaining first DCT coefficients; extracting magnitudes and signs of the first DCT coefficients individually; applying DCT to the magnitudes of the first DCT coefficients and obtaining second DCT coefficients; dividing the second DCT coefficients into DC components and DCT coefficients excluding the DC components and setting the DCT coefficients excluding the DC components as third DCT coefficients; calculating RMS values of the third DCT coefficients; and respectively quantizing the DC components, the RMS values of the third DCT coefficients, the third DCT coefficients, and the signs of the first DCT coefficients. 42. The method of claim 41, wherein the respectively quantizing of the DC components, the RMS values of the third DCT coefficients, the third DCT coefficients, and the signs of the first DCT coefficients comprises: quantizing the DC components using inter-band prediction quantization; quantizing the RMS values of the third DCT coefficients using intra-band prediction quantization; quantizing the third DCT coefficients so that a predetermined number of the third DCT coefficients of each band are quantized, and the remaining third DCT coefficients are removed; and quantizing the signs of the first DCT coefficients according to magnitudes of the first DCT coefficients. 43. The method of claim 42, wherein the inter-band prediction quantization for the DC components obtains inter-band DC prediction errors according to the equation: Δ0=D0−Gĝc Δi=Di−G{circumflex over (D)}i−1, i=1, 2, 3, . . . , (1) and quantizes the inter-band DC prediction errors, wherein Di is a log DC value at an i-th band of high-band speech signal, {circumflex over (D)}i is a quantized log DC value at the i-th band of high-band speech signal, ĝc, is a log energy of a low-band signal, G is a prediction coefficient of the predictor unit, and Δi is a DC prediction error of the i-th band of the high-band speech signal. 44. The method of claim 42, wherein the quantizing the RMS values of the third DCT coefficients using the intra-band prediction quantization comprises using the RMS values of the third DCT coefficients and quantized DC values of the second DCT coefficients. 45. The method of claim 42, wherein quantizing the predetermined number of third DCT coefficients of each band quantized is higher in response to the band having a high priority, and lower in response to the band having a low priority. 46. The method of claim 42, wherein the quantizing the signs of the first DCT coefficients comprises quantizing a predetermined number of the signs of the first DCT coefficients in a descending order of magnitude from a first DCT coefficient with a maximum magnitude, and removes the signs of the remaining first DCT coefficients. 47. A method of decompressing a compressed wide-band speech signal having a high-band speech packet and a low-band speech packet compressed with a scalable bandwidth structure, the method comprising: decompressing the low-band speech packet into a low-band speech signal; decompressing the high-band speech packet into a high-band speech signal using energy information of the decompressed low-band speech signal obtained in the decompressing of the low-band speech signal; and adding the low-band speech signal with the high-band speech signal and generating a wide-band decompression signal. 48. The method of claim 47, wherein the decompressing of the high-band speech signal comprises: dequantizing the high-band speech packet according to modules for decompressing the wide-band speech signal; extracting magnitudes of first DCT coefficients dequantized by the dequantization; extracting signs of the first DCT coefficients generated by the dequantization; inserting the signs of the first DCT coefficients to the first DCT coefficients according to magnitude order information for the first dequantized DCT coefficients; predicting signs of the first DCT coefficients which are not received using the magnitude order information of the first dequantized DCT coefficients and first dequantized DCT coefficients in a previous frame; inserting the predicted signs of the first DCT coefficients to the corresponding first dequantized DCT coefficients; and applying inverse DCT to the corresponding first dequantized DCT coefficients, obtaining a time-domain signal for each band, and outputting the high-band speech signal. 49. An apparatus to compress a wide-band speech signal, the apparatus comprising: a high-band speech compressor to compress a high-band speech signal of the wide-band speech signal according to energy information regarding a low-band speech signal of the wide-band speech signal; wherein the compressed high-band speech signal is output as a high-band speech packet. 50. The apparatus of claim 49, further comprising a low-band speech compressor to compress the low-band speech signal and output the energy information regarding the low-band speech signal. 51. The apparatus of claim 50, wherein the low-band speech compressor outputs the compressed low-band speech signal as a low-band speech packet. 52. An apparatus to compress a wide-band speech signal, the apparatus comprising: a low-band speech compressor to compress a low-band speech signal of the wide-band speech signal and determine energy information regarding the low-band speech signal; wherein the compressed low-band speech signal is output as a low-band speech packet. 53. The apparatus of claim 52, further comprising a high-band speech compressor to compress a high-band speech signal according to the energy information regarding the low-band speech signal. 54. An apparatus to decompress a compressed wide-band speech signal having a compressed low-band speech packet and a compressed high-band speech packet, the apparatus comprising: a high-band speech decompressor to decompress the compressed high-band speech packet according to energy information regarding a low-band speech signal; wherein the low-band speech signal is obtained by decompressing the low-band speech packet. 55. The apparatus of claim 54, further comprising a low-band speech decompressor to decompress the low-band speech packet into a low-band speech signal and provide the energy information to the high-band speech decompressor. 56. The apparatus of claim 55, further comprising an adder to add the low-band speech signal and the high-band speech signal to output the decompressed wide-band speech signal. 57. An apparatus to decompress a compressed wide-band speech signal having a compressed low-band speech packet and a compressed high-band speech packet, the apparatus comprising: a low-band speech decompressor to decompress the low-band speech packet and output a low-band speech signal; wherein low-band speech decompressor determines energy information regarding the low-band speech signal. 58. The apparatus of claim 57, further comprising a high-band speech decompressor to decompress the high-band speech packet into a high-band speech signal according to the energy information regarding the low-band speech signal. 59. The apparatus of claim 58, further comprising an adder to add the low-band speech signal and the high-band speech signal to output the decompressed wide-band speech signal. 60. A method of compressing a wide-band speech signal, the method comprising: determining energy information regarding a low-band signal of the wide-band speech signal; and compressing a high-band signal of the wide-band speech signal according to the energy information regarding the low-band signal. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Korean Patent Application No. 2003-48665, filed on Jul. 16, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to encoding and decoding of a speech signal, and, more particularly, to a wide-band speech signal compression apparatus to compress a speech signal in a scalable bandwidth structure, a wide-band speech signal decompression apparatus to decompress the compressed speech signal, and a method thereof. 2. Description of the Related Art An existing communication method based on Public Switched Telephone Network (PSTN) samples a speech signal at 8 kHz and transmits a speech signal with a bandwidth of 4 kHz. Accordingly, such a PSTN-based communication method cannot transmit speech signals of a frequency beyond 4 kHz, which deteriorates the voice quality of the speech signal. To solve such a problem, a packet-based wide-band speech signal compression apparatus that samples a received speech signal at 16 kHz, and provides a speech signal with a bandwidth of 8 kHz, has been developed. However, although the quality of the speech signal improves as the bandwidth of the speech signal increases, the amount of data transmission of the communication channel increases. Therefore, to efficiently operate the wide-band speech signal compression apparatus, an adequate communication channel for transmitting large amounts of data should be ensured. However, the amount of data transmission on the packet-based communication channel may be changed according to various factors. Accordingly, the adequate communication channel required by the wide-band speech signal compression apparatus may not be ensured, which can deteriorate the voice quality of the speech signal. That is, if the amount of data transmission on the communication channel is not enough at a specific moment, the speech packet is lost during transmission, so that the speech signal cannot be transmitted. Accordingly, a technique which compresses speech signals by a scalable bandwidth has been proposed. An example of such a technique is ITU standard G.722. The ITU standard G.722 proposes a method that divides a received speech signal into two bands, using a low-pass filter and a high-pass filter, and compresses the respective bands individually. In the ITU standard G.722, the signals are compressed according to an Adaptive Differential Pulse Sign Modulation (ADPCM) method. However, the compression method proposed in the ITU standard G.722 has a very high data transmission rate. Also, the ITU standard G.722.1 discloses a technique that converts a wide-band signal into a frequency-domain signal, divides the frequency-domain signal into several sub-band signals, and compresses the respective sub-band signals. However, the ITU standard G.722.1 is not compatible with a standard narrow-band speech signal compression apparatus, and it also does not construct a speech packet in a scalable bandwidth structure. A conventional wide-band speech signal compression technique, developed to be compatible with a standard narrow-band speech signal compression apparatus, passes a wide-band speech signal through a low-pass filter to obtain a narrow-band speech signal, encodes the narrow-band speech signal using a standard narrow-band speech signal compressor, and compresses a high-band speech signal using a separate method. Here, packets of the narrow-band speech signal and the high-band speech signal are transmitted in a scalable structure. A conventional technique for processing a high-band speech signal divides a high-band speech signal into a plurality of sub-band signals using a filter-bank, and compresses the respective sub-band signals. Another conventional technique for compressing a high-band speech signal converts the high-band speech signal into a frequency-domain signal by discrete cosine transform (DCT) or discrete Fourier transform (DFT) and quantizes the generated frequency coefficients individually. However, since such wide-band speech signal compression techniques having a scalable bandwidth structure do not use the characteristics of the narrow-band speech signal when compressing the high-band speech signal, they have a low compression efficiency. Also, since these wide-band speech signal compression techniques quantize all frequency coefficients converted to a frequency domain without efficient use of the correlation of intra-band and inter-band, they have a low quantization efficiency and a low prediction performance in decompressing information not transmitted when the signal was compressed. SUMMARY OF THE INVENTION The present invention provides a wide-band speech signal compression apparatus that is compatible with a conventional standard narrow-band speech signal compressor, a wide-band speech signal decompression apparatus, and a method thereof. The present invention also provides a wide-band speech signal compression apparatus and a wide-band speech signal decompression apparatus to compress a high-band speech signal using compression information of a low-band speech signal and decompress the compressed speech signal, when compressing and decompressing a speech signal using a scalable bandwidth structure, respectively, and a method thereof. The present invention also provides a wide-band speech signal compression apparatus and a wide-band speech signal decompression apparatus to compress a high-band speech signal using a correlation of inter-band and intra-band and decompress the compressed high-band speech signal, and a method thereof. The present invention also provides a wide-band speech signal compression apparatus and a wide-band speech signal decompression apparatus to respectively quantize frequency coefficients, obtained by converting speech signals to frequency domain signals, differently according to the characteristics of frequency coefficients and their bands when compressing the speech signals, and decompress the compressed speech signals, and a method thereof. The present invention also provides a speech decompression apparatus to minimize information loss in decompressing, by predicting information not transmitted due to compression by a speech compressor apparatus, and a method thereof. Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. According to an aspect of the present invention, there is provided an apparatus to compress a wide-band speech signal, the apparatus comprising: a narrow-band speech compressor to compress a low-band speech signal of the wide-band speech signal and output the compressed low-band speech signal as a low-band speech packet; and a high-band speech compressor to compress a high-band speech signal of the wide-band speech signal using energy information of the low-band speech signal provided from the narrow-band speech compressor, and outputs the compressed high-band speech signal as a high-band speech packet. According to another aspect of the present invention, there is provided an apparatus to decompress a wide-band speech signal, the wide-band speech signal including a compressed low-band speech packet and a compressed high-band speech packet, the apparatus comprising: a narrow-band speech decompressor to decompress the compressed low-band speech packet into a low-band speech signal; a high-band speech decompressor to decompress the compressed high-band speech packet into a high-band speech signal using energy information of the decompressed low-band speech signal provided from the narrow-band speech decompressor; and an adder to add the low-band speech signal output from the narrow-band speech decompressor with the high-band speech signal output from the high-band speech decompressor and output the decompressed wide band speech signal. According to still another aspect of the present invention, there is provided a method of compressing a wide-band speech signal, the method comprising: receiving the wide-band speech signal and compressing a high-band speech signal of the wide-band speech signal using energy of a low-band signal of the wide-band speech signal; and outputting the compressed high-band speech signal as a high-band speech packet. According to still yet another aspect of the present invention, there is provided a method of decompressing a compressed wide-band speech signal having a high-band speech packet and a low-band speech packet being compressed with a scalable bandwidth structure, the method comprising: decompressing the low-band speech packet into a low-band speech signal; decompressing the high-band speech packet into a high-band speech signal using energy information of the decompressed low-band speech signal obtained in the decompressing of the low-band speech signal; and adding the low-band speech signal with the high-band speech signal and generating a wide-band decompression signal. BRIEF DESCRIPTION OF THE DRAWINGS These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: FIG. 1 is a block diagram of a wide-band speech signal compression apparatus according to an embodiment of the present invention; FIG. 2 is a block diagram of a high-band speech compressor shown in FIG. 1; FIG. 3 is a detailed block diagram of a band signal quantization module shown in FIG. 2; FIG. 4 is a detailed block diagram of a DC quantization module shown in FIG. 3; FIG. 5 is a detailed block diagram of an RMS quantization module shown in FIG. 3; FIG. 6 is a detailed block diagram of a sign quantization module shown in FIG. 3; FIG. 7 is a block diagram of a wide-band speech signal decompression apparatus according to an embodiment of the present invention; FIG. 8 is a detailed block diagram of a high-band speech decompression apparatus shown in FIG. 7; FIG. 9 is a detailed block diagram of a sign predictor module shown in FIG. 8; FIG. 10 is a flowchart illustrating a process of compressing a high-band speech signal in a wide-band speech signal compression method according to an embodiment of the present invention; and FIG. 11 is a flowchart illustrating a process for decompressing a high-band speech signal in the wide-band speech signal decompression method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. FIG. 1 is a block diagram of a wide-band speech signal compression apparatus according to the present invention. Referring to FIG. 1, the wide-band speech signal compression apparatus includes a first bandwidth conversion unit 102, a narrow-band speech compressor 106, and a high-band speech compressor 107. The first bandwidth conversion unit 102 converts a wide-band speech signal received via a line 101 into a narrow-band signal. The wide-band speech signal is a signal obtained by sampling an analog signal at 16 kHz and quantizing each sampled signal using 16-bit linear Pulse Code Modulation (PCM). The first bandwidth conversion unit 102 includes a low-pass filter 104 and a down-sampler 105. The low-pass filter 104 filters the wide-band speech signal received via the line 101 according to a cut-off-frequency. The cut-off frequency is determined according to the bandwidth of a narrow-band defined according to a scalable bandwidth structure. For example, the cut-off frequency of the low-pass filter 104 is 3700 Hz. However, the low-pass filter is not limited to this cut-off frequency. The down sampler 105 samples the signal output from the low-pass filter 104 by ½ down-sampling to output a low-band signal of a narrow-band 103. The low-band signal of the narrow-band 103 is output to the narrow-band speech compressor 106. The narrow-band speech compressor 106 compresses the low-band signal of the narrow-band 103 to output a low-band speech packet 108. The low-band speech packet 108 is transferred to a communication channel (not shown). The narrow-band speech compressor 106 calculates the energy of the low-band speech signal when compressing the low-band signal of the narrow-band. The energy of the low-band speech signal can be calculated using a method that calculates quantized fixed codebook gains for frames. Information regarding the energy of the low-band speech signal is included in the low-band speech packet 108. The narrow-band speech compressor 106 transmits the low-band speech packet 108, including the energy information of the low-band speech signal, to a communication channel (not shown), and simultaneously provides the energy information of the low-band speech signal to the high-band speech compressor 107 via the line 110. The high-band speech compressor 107 compresses the high-band speech signal of the wide-band speech signal transmitted via the line 101 to output a high-band speech packet. The high-band speech packet is transferred to a communication channel (not shown) via the line 109. The high-band speech compressor 107 is shown in FIG. 2. Referring to FIG. 2, the high-band speech compressor 107 includes a filter bank 201, a band Root-Mean-Square (RMS) value calculator 203, a band priority decision unit 205, a band signal quantization module 207, and a packetizer 209. The filter bank 201 receives a wide-band speech signal from the line 101 and divides the wide-band speech signal into a plurality of band signals. For example, the filter bank 201 can divide the wide-band speech signal into four band signals with different bandwidths, using center frequencies of 4000 Hz, 4800 Hz, 5800 Hz, and 7000 Hz. The filter bank 201 may be an existing Gammatone filter bank. The filer bank 201 according to an embodiment of the present invention can operate by a 30 msec frame. Each band signal transferred via a line 202 may include 480 samples. The divided bands can be defined as bands 0 through 3. The RMS value calculator 203 receives the band signals via the line 202 and calculates an RMS value for each of the band signals individually. The calculated RMS values are provided to the band priority decision unit 205 via a line 204. The band priority decision unit 205 determines a priority of each band according to the magnitude of the RMS values for each of the bands. That is, the band priority decision unit 205 determines a significance of each band according to the magnitude of each band's respective RMS value, and outputs the significance information of each band via a line 206. The band signal quantization module 207 receives the band signals via the line 202 and quantizes the band signals. When quantizing the band signals, the band signal quantization module 207 uses the significance information of the band transmitted from the band priority decision unit via the line 206 and the energy information of the low-band signal transmitted from the narrow-band speech compressor 106 via the line 110. If the filter bank 201 operates by the 30 msec frame, the band signal quantization module 207 also operates by the 30 msec frame. The band signal quantization module 207 is shown in FIG. 3. Referring to FIG. 3, the band signal quantization module 207 includes a first Discrete Cosine Transform (DCT) calculator 301, a magnitude extractor 303, a sign extractor 304, a second DCT calculator 307, a Direct Current (DC) divider 309, a DC quantization module 311, an RMS value calculator 314, an RMS value quantization module 316, a normalizer 318, a DCT coefficient quantizer 320, a sign quantization module 322, and a data combination unit 324. The first DCT calculator 301 performs a DCT on each band signal to calculate a first DCT coefficient for each band. That is, if each band signal includes 480 samples, the first DCT calculator 301 performs a 480-point DCT on each band signal to obtain a first DCT coefficient for each band. Since each of the band signals is a signal with a specific frequency band, the first DCT coefficients output from the first DCT calculator 301 via a line 302 are limited to DCT coefficients of the corresponding frequency band. If the filter bank 201 divides the wide-band speech signal into the four band signals with the different bandwidths, as described above with reference to FIG. 2, start indexes and end indexes of the first DCT coefficients among the 480 DCT coefficients for each band which are output from the first DCT calculator 301, and the number of the first DCT coefficients for each band, can be defined as in Table 1. The number of the first DCT coefficients of a band i is denoted by Ni. TABLE 1 Number of Band Start index End index coefficients 0 220 263 44 1 264 317 54 2 318 383 66 3 384 425 42 The first DCT coefficients for each band are provided to the magnitude extractor 303 and the sign extractor 304 via the line 302. The magnitude extractor 303 extracts the magnitudes of the received first DCT coefficients for each band. The sign extractor 304 extracts the signs of the received first DCT coefficients for each band. The magnitude information of the first DCT coefficients output from the magnitude extractor 303 is transmitted to the second DCT calculator 307 via a line 305. The sign information of the first DCT coefficients output from the sign extractor 304 is transmitted to the sign quantization module 322 via a line 306. The second DCT calculator 307 calculates second DCT coefficients for each band. Since the number Ni of the first DCT coefficients is different according to each of the bands, the second DCT calculator 307 performs an Ni-point DCT according to the number Ni of the first DCT coefficients for each band and calculates second DCT coefficients for each band. The second DCT coefficients for each band are output to the DC divider 309 via a line 308. The DC divider 309 divides the second DCT coefficients 308 for each band into a DC component and the remaining DCT coefficients, wherein the DC component for each band is the DC component of the second DCT coefficients, and the remaining DCT coefficients are the third DCT coefficients. The DC component of the second DCT coefficients is the DCT coefficient of index 0, and the remaining indexes 1 through Ni−1 of the second DCT coefficients correspond to the third DCT coefficients. Accordingly, the number of the third DCT coefficients for each band is Ni−1. The DC components are output via a line 310, and the third DCT coefficients are output via a line 313. The DC quantization module 311 receives and quantizes the DC components of the second DCT coefficients. The DC quantization module 311 is constructed as shown in FIG. 4. Referring to FIG. 4, the DC quantization module 311 includes an inter-band predictor unit 401, a DC quantizer 403, and a DC dequantizer 404. The inter-band predictor unit 401 performs inter-band prediction for the DC component of each band to compute a DC prediction error. The inter-band predictor unit 401 may be a 1st-order Auto-Regressive (AR) model. Prediction for a first band is performed using quantized energy information of the low-band signal received via the line 110. For example, in a case where a G.729 narrow-band speech compressor is used as the narrow-band speech compressor 106, since an average value of quantized fixed codebook gains for 30 msec corresponds to the quantized energy information of the low-band signal, the inter-band predictor unit 401 computes a DC prediction error of a first band using the average value of the quantized fixed codebook gains. If a log DC value at a band i is Di, a DC prediction error at the band i is Δi, and the average value of the quantized fixed codebook gains for 30 msec is ĝc, a DC prediction error Δ0 at a first band is calculated using the following equation 1. Δ0=D0−Gĝc (1) Here, G is a prediction coefficient, G=1.0 in this embodiment, and D0 is a log DC value at the first band. Then, DC prediction errors for the remaining bands are computed in order. The DC prediction errors for the remaining bands are detected using equation 2. Δi=Di−G{circumflex over (D)}i−1, i=1, 2, 3 (2) Here, {circumflex over (D)}i is a dequantized log DC value at the band i, calculated by the DC dequantizer 404, and G is the prediction coefficient, G=1.0 in this embodiment. The DC quantizer 403 receives and quantizes the DC prediction error. That is, the DC quantizer 403 performs independent scalar quantization for each band according to the statistical characteristic of the DC prediction error received via a line 402 and outputs a DC quantization index via a line 312. The DC quantization index output from the DC quantizer 403 is input to the data combination unit 324 of FIG. 3 and the DC dequantizer of FIG. 4. The DC dequantizer 404 detects the dequantized log DC value {circumflex over (D)}i required for inter-band DC prediction using the DC quantization index. The dequantized log DC value {circumflex over (D)}i is computed using equation 3. The dequantized log DC value {circumflex over (D)}i is provided to the inter-band predictor unit 401 via a line 405. D0=Δ0+Gĝc {circumflex over (D)}i={circumflex over (Δ)}i+G{circumflex over (D)}i−1 i=1, 2, 3 (3) The RMS value calculator 314 of FIG. 3 receives the third DCT coefficients via the line 313 and calculates RMS values of the third DCT coefficients for each band. The RMS values of the third DCT coefficients for each band are provided to the RMS value quantization module 316. The RMS value quantization module 316 is constructed as shown in FIG. 5. Referring to FIG. 5, the RMS value quantization module 316 includes an intra-band predictor unit 501, a DC dequantizer 504, and an RMS value quantizer 503. The DC dequantizer 504 performs the same operation as the DC dequantizer 404 of FIG. 4. Accordingly, the DC dequantizer 504 receives a DC quantization index for each band via the line 312 and obtains a dequantized log DC value for each band using the DC quantization index. The dequantized log DC value has the same value as the value output from the DC dequantizer 404 of FIG. 4. The intra-band predictor unit 501 predicts an RMS value at each band based on the dequantized log DC value for each band received via a line 505 and computes an RMS prediction error. The computed RMS prediction error is output to the RMS value quantizer 503. The RMS value quantizer 503 quantizes the RMS prediction error and outputs an RMS value quantization index via a line 317. The intra-band predictor unit 501 performs a 1st-order AR model prediction according to equation 4 and obtains an RMS prediction error δi. δi=si−G{circumflex over (D)}i i=0, 1, 2, 3 (4) Here, si is the log RMS value at the band i, and G is the prediction coefficient, G=1.0 in this embodiment. The RMS value quantizer 503 performs scalar quantizations for each band, independently, according to the statistical characteristic of the RMS prediction error, and outputs RMS value quantization indexes via a line 317. The normalizer 318 of FIG. 3 normalizes the third DCT coefficients received via a line 313 with quantized RMS values for each band. The normalizer 318 obtains the quantized RMS values for each band from the RMS value quantization indexes received via a line 317. The normalizer 318 divides the third DCT coefficients by the quantized RMS values, for each of the bands, respectively, detects normalized third DCT coefficients, and outputs the normalized third DCT coefficients via a line 319. The DCT coefficient quantizer 320 receives and vector-quantizes the normalized third DCT coefficients and outputs third DCT coefficient quantization indexes via a line 321. That is, the DCT coefficient quantizer 320 splits the third DCT coefficients normalized for each band into a plurality of subvectors and performs vector-quantization for each subvector, using a split vector quantization method. Also, the DCT coefficient quantizer 320 performs different quantization operations according to the band priority information received via the line 206. That is, the magnitudes of the first DCT coefficients for each band have a high correlation in an intra-band. Due to the high correlation, an energy compaction phenomenon appears significantly in the second DCT coefficients and the third DCT coefficients. Accordingly, the greater part of the energy of the third DCT coefficients is distributed in the DCT coefficients having upper indexes. Therefore, although the third DCT coefficients having lower indexes are removed, and thereby are not transferred, a decompressed speech signal includes little degradation. Accordingly, the DCT coefficient quantizer 320 quantizes the third DCT coefficients of the upper indexes among the third DCT coefficients. Indexes of coefficients to be quantized among the third DCT coefficients of each band are determined according to the band priority information provided via the line 206. The DCT coefficient quantizer 320 quantizes a very small number of the third DCT coefficients at a band with a lowest priority, and quantizes a larger number of the third DCT coefficients at a band with a higher priority. For example, when performing quantizations for four bands and splitting the third DCT coefficients to be quantized into three sub-vectors, the DCT coefficient quantizer 320 quantizes only an upper sub-vector at a band with a lowest priority, quantizes only two upper sub-vectors at a band with a second lower priority, and quantizes all three sub-vectors at the remaining two bands, on the basis of the band priority information. The entire indexes of the third DCT coefficients for the four bands and the indexes of the three sub-vectors can be defined as in Table 2. As seen in Table 2, the third DCT coefficients having the lower indexes than index 29 are removed and not transferred regardless of their band priorities. This is because the number of the DCT coefficients that are actually quantized at each band is 30. TABLE 2 First Second Third sub-vector sub-vector sub-vector Band Entire indexes indexes indexes indexes 0 0-42 0-9 10-19 20-29 1 0-52 0-9 10-19 20-29 2 0-64 0-9 10-19 20-29 3 0-40 0-9 10-19 20-29 The sign quantization module 322 receives and quantizes signs of the first DCT coefficients via a line 306 and outputs sign quantization indexes via a line 323. The sign quantization module 322 is shown in FIG. 6. Referring to FIG. 6, the sign quantization module 322 includes a DCT coefficient dequantizer 601, a DC dequantizer 603, an inverse DCT calculator 605, an arrangement unit 607, and a sign quantizer 609. The DCT coefficient dequantizer 601 performs dequantization for the third DCT coefficient quantization indexes received via the line 321 and outputs third dequantized DCT coefficients via a line 602. The DC dequantizer 603 performs DC dequantization for the DC quantization indexes of the second DCT coefficients received via the line 312 and outputs dequantized DC values via a line 604. The inverse DCT calculator 605 calculates second dequantized DCT coefficients using the third dequantized DCT coefficients and the dequantized DC values of the second DCT coefficients, and obtains magnitudes of the first dequantized DCT coefficients using these second dequantized DCT coefficients. The inverse DCT calculator 605 outputs the magnitudes of the first dequantized DCT coefficients via a line 606. The arrangement unit 607 obtains order information for the magnitudes of the first DCT coefficients dequantized at each band. The sign quantizer 609 quantizes signs of the first DCT coefficients with large magnitude among the signs of the first DCT coefficients received via the line 306, on the basis of the order information provided from the arrangement unit 607, and removes and does not transfer the remaining signs. Accordingly, the sign quantizer 609 quantizes a predetermined number of signs of the first DCT coefficients selected based on the magnitude order of the first DCT coefficients, and outputs sign quantization indexes each quantized using one bit via a line 323. Here, the quantized signs are output in the same order as the magnitude order of the first DCT coefficients. Reinsertions of signs when decompressing a speech signal are performed correctly according to this order. Table 3 shows the number of coefficients to be subjected to sign quantization at each of the bands, according to this embodiment of the present invention. TABLE 3 The number of The number coefficients to of entire be subjected to sign Band coefficients quantization 0 44 30 1 54 32 2 66 32 3 42 21 As seen in Table 3, the sign quantizer 609 quantizes signs of coefficients with larger magnitudes among the entire number of coefficients. For example, in a case of band 0 of Table 3, the number of entire DCT coefficients is 44, while the number of DCT coefficients to be subjected to sign quantization is 30. Here, the DCT coefficients to be subjected to sign quantization are the 30 DCT coefficients with the largest magnitude among the 44 DCT coefficients. The data combination unit 324 of FIG. 3 combines the DC quantization indexes of the second DCT coefficients received via the line 312, the RMS quantization indexes of the third DCT coefficients received via the line 317, the third DCT coefficient quantization indexes received via the line 321, and the sign quantization indexes of the first DCT coefficients received via the line 323 and outputs the combined signal via a line 208. The packetizer 209 of FIG. 2 packetizes the band priority information output from the band priority decision unit 205 and the combined signal output from the data combination unit 324 to output the packetized signal via a line 109. The packetized signal is a high-band speech packet. If a band signal for each band includes 480 samples, the numbers of bits assigned to each of the quantization indexes output by quantization according to this embodiment of the present invention can be defined as in Table 4, here the high-band speech packet has a transmission rate of 8 kbps. TABLE 4 Band 0 Band 1 Band 2 Band 3 Sum Band priority 4 DC quantization 6 6 6 6 24 RMS quantization 4 4 4 4 16 DCT 9 subvector * 9 bit 81 coefficient quantization Sign quantization 30 32 32 21 115 Total 240 FIG. 7 is a block diagram of a wide-band speech signal decompression apparatus according to an embodiment of the present invention. Referring to FIG. 7, the wide-band speech signal decompression apparatus includes a narrow-band speech decompressor 702, a second bandwidth conversion unit 704, a high-band speech decompressor 707, and an adder 709. The narrow-band speech decompressor 702 is constructed in correspondence to the structure of the narrow-band speech compressor 106 of FIG. 1. The narrow-band speech decompressor 702 receives a low-band speech packet via the line 701 and outputs a decompressed low-band speech signal of the narrow-band via the line 703. The second bandwidth conversion unit 704 converts the decompressed narrow-band low-band speech signal into a decompressed low-band signal of the wide-band. The second bandwidth conversion unit 704 includes an up-sampler 710 and a low-pass filter 711. The up-sampler 710 receives a decompressed low-band speech signal of the narrow-band via the line 703 and inserts a zero sample between samples, thereby performing up-sampling. The low-pass filter 711 operates in the same manner as the low-pass filter 104 of FIG. 1. The high-band speech decompressor 707 receives a high-band speech packet via the line 706 and obtains a decompressed high-band speech signal using energy information of the decompressed low-band signal provided from the narrow-band speech decompressor 702 via the line 703. The high-band speech decompressor 707 is constructed in correspondence to the structure of the high-band speech compressor 107 of FIG. 2. The high-band speech decompressor 707 is shown in FIG. 8. Referring to FIG. 8, the high-band speech decompressor 707 includes an inverse packetizer 801, a sign dequantizer 806, a DC dequantizer 808, a DCT coefficient dequantizer 810, an RMS value dequantizer 812, a multiplier 814, an inverse DCT calculator 816, an arrangement unit 818, a sign insertion module 820, a sign predictor module 822, an inverse DCT calculator 824, a filter bank 826, an adder 828, and a frame delay device 829. The inverse packetizer 801 receives the high-band speech packet via the line 706, splits the quantized indexes according to the respective modules, and outputs the split results to the respective modules. The sign dequantizer 806 dequantizes sign quantized indexes transferred from the inverse packetizer 801 via the line 802, and outputs the dequantized result as first DCT coefficient signs. The DC dequantizer 808 outputs quantized DC values of second DCT coefficients using the DC quantized indexes transferred from the inverse packetizer 801 via the line 803 and the energy information of the low-band signal received via the line 703. The DC dequantizer 808 operates in the same manner as the DC dequantizer 404 of FIG. 4. The DCT coefficient dequantizer 810 outputs normalized and quantized third DCT coefficients 811 using the DCT coefficient quantization indexes provided from the inverse packetizer 801 via the line 804 and the band priority information provided via the line 830. The DCT coefficient dequantizer 810 operates in the same manner as the DCT coefficient dequantizer 601 of FIG. 6. The RMS value dequantizer 812 outputs RMS values of the third quantized DCT coefficients using RMS quantization indexes provided from the inverse packetizer 801 via the line 805 and the quantized DC values of the second DCT coefficients provided from the DC dequantizer 808 via the line 809. The RMS value dequantizer 812 performs the inverse process of that performed by the RMS value quantization module 316 of FIG. 3. Accordingly, the dequantization process of the RMS value dequantizer 812 is defined by equation 5. −ŝi={circumflex over (δ)}i+G{circumflex over (D)}i i=0, 1, 2, 3 (5) The multiplier 814 multiplies the third DCT coefficients received via the line 811 by the RMS values of the third DCT coefficients received via the line 813, and obtains third quantized DCT coefficients. The inverse DCT calculator 816 combines the third quantized DCT coefficients received via the line 815 with the quantized DC values of the second DCT coefficients received via the line 809 and outputs magnitudes of first quantized DCT coefficients. The inverse DCT calculator 816 operates in the same manner as the inverse DCT calculator 605 of FIG. 6. The DC dequantizer 808, the RMS value dequantizer 812, the DCT coefficient dequantizer 810, the multiplier 814, and the inverse DCT calculator 816 dequantize the band priority information, the third DCT quantization indexes, the DC quantization indexes of the second DCT coefficients, and the RMS quantization indexes of the third DCT coefficients to obtain dequantized DCT values. The above-mentioned units can be defined as an inverse DCT calculation module for obtaining the magnitudes of first quantized DCT coefficients using the quantized DCT values. The arrangement unit 818 receives the magnitudes of the first quantized DCT coefficients via the line 817 and obtains order information for the magnitudes of the first quantized DCT coefficients. The sign insertion unit 820 inserts the first DCT coefficient signs transmitted via the line 807 to the magnitudes of the first DCT coefficients in the magnitude order of the first DCT coefficients using the order information provided from the arrangement unit 818. The sign predictor module 822 predicts the signs of the first DCT coefficients with small magnitudes to which signs are not assigned from the sign insertion unit 820. The sign predictor module 822 is constructed as shown in FIG. 9. Referring to FIG. 9, the sign predictor module 822 includes a first time-domain converter 901, a second time-domain converter 901′, a signal predictor unit 904, and a sign selector 906. The first time-domain converter 901 inserts positive signs (+) to the magnitudes of the first DCT coefficients received via the line 819 to which signs are not assigned from the sign insertion unit 820, and outputs time-domain information based on the positive sign (+) by performing an inverse DCT. The second time-domain converter 901′ inserts negative signs (−) to the magnitudes of the first DCT coefficients received via the line 819 to which signs are not assigned from the sign insertion unit 820, and outputs time-domain information based on the negative sign (−) by performing an inverse DCT. In this embodiment, the time-domain converters 901 and 901′ output the first sample value of the time-domain signal based on the respective signs, that is, output a sample value obtained by substituting a time index n=0 to the time-domain signal defined by equation 6. In equation 6, L is the number of DCT points. Accordingly, in a case where the DCT with 480 points is performed (see the above description related to the first DCT calculator 301), L can be set to 480. p m + [ n ] [ k ] = c ^ m [ k ] cos ( π k ( 2 n + 1 ) 2 L ) p m - [ n ] [ k ] = - c ^ m [ k ] cos ( π k ( 2 n + 1 ) 2 L ) ( 6 ) In equation 6, pm+[n][k] and pm−[n][k] represent sample values at a time index n for a first DCT coefficient of index k in a present frame m, respectively, and |ĉm[k]| is the magnitude of a first quantized DCT coefficient of index k in a present frame m. The sample values are output via the lines 902 and 903. In another embodiment of the present invention, the first and second time-domain converters 901 and 901′ output gradients at the first sample value of the time-domain signals based on the respective signs, and output values obtained by differentiating a time-domain signal defined by the equation 6 with respect to n and substituting n=0 to the differentiated result. The signal predictor unit 904 predicts time-domain information for a signal of a present frame for respective frequency indexes from the first quantized DCT coefficients of the previous frame provided via the line 830 from the frame delay unit 829. The signal predictor unit 904 outputs a value obtained by substituting an index of n=0 to the signal calculated by equation 7 as time-domain prediction information. p ^ m [ n ] [ k ] = p m - 1 [ n + L ] [ k ] = c ^ m - 1 [ k ] cos ( π k ( 2 n + L ) + 1 2 L ) ( 7 ) In equation 7, {circumflex over (p)}m[n][k] is time-domain prediction information for a DCT coefficient index k output via the line 905, and pm−1[n+L][k] is a sample value corresponding to a time index n+L calculated in a previous frame m−1. Since a time index in one frame is from 0 to L−1, pm−1[n+L][k] is a sample value of a present frame obtained in the previous frame. The sign selector 906 compares the time-domain prediction information predicted for each of the first DCT coefficient indexes received via the line 905 with the actually calculated time-domain information received via the lines 902 and 903, and determines a sign nearest to the prediction information as a final sign of the first DCT coefficient. The final sign of the first DCT coefficient is output via the line 823. In another embodiment of the present invention, the signal predictor unit 904 predicts a time-domain signal of a present frame using the first quantized DCT coefficients in the previous frame for each DCT coefficient index, and outputs a gradient at index n=0. That is, the signal predictor unit 904 differentiates a signal obtained by equation 7 with respect to n, and outputs a value obtained by substituting n=0 to the differentiated result. The inverse DCT calculator 824 receives the magnitudes and signs of the first quantized DCT coefficients via the lines 821 and 823 and outputs a time-domain signal quantized for each band using the magnitudes and signs. The time-domain signal quantized for each band is input to the filter bank 826 via the line 825. The filter bank 826 is constructed in correspondence to the filter bank 201 of FIG. 2. Accordingly, in the filter bank 826, each band is defined by the same center frequency as that defined in the filter bank 201. The filter bank 826 obtains a final speech signal for each band using the quantized time-domain signal for each band, and outputs the final speech signal via the line 827. The adder 828 adds the speech signals for each of the bands transmitted from the filter bank 826, and obtains a finally decompressed high-band speech signal. The decompressed high-band speech signal is output via the line 708. The filter bank 826 and adder 828 can construct a decompressor, which obtains the speech signals for each of the bands using the quantized signals in the time domain for each of the bands transmitted from the inverse DCT calculator 824, and decompresses a high-band speech signal using the speech signals for each of the bands. The frame delay device 829 receives the magnitudes and signs of the first DCT coefficients transmitted from the sign insertion unit 820 and the sign predictor module 822, and provides first quantized DCT coefficients, delayed by one frame using the magnitudes and signs of the first DCT coefficients, to the coding module 822. Accordingly, a signal transmitted from the frame delay device 829 via the line 830 is high-band signal information (DCT coefficients) in the previous frame. The adder 709 adds a decompressed low-band signal of a wide-band and the finally decompressed high-band speech signal received via the line 708 and outputs a wide-band decompressed signal via the line 712. The method of compressing the low-band speech signal of the wide-band speech signal, according to this embodiment of the present invention, converts the wide-band speech signal into a low-band speech signal of a narrow-band and compresses the low-band speech signal as described with reference to FIG. 1. The compressed low-band speech signal is transmitted as a low-band speech packet. The compressed low-band speech signal includes energy information of the low-band signal. FIG. 10 is a flowchart illustrating a process for compressing a high-band speech signal in a wide-band speech signal compression method according to an embodiment of the present invention. If a wide-band speech signal is input to the filter bank 201, the wide-band speech signal is split into a plurality of signals with different frequency bands by the filter bank 201 in operation 1001. In operation 1002, RMS values for each of the frequency bands are calculated by the RMS calculator 203 of FIG. 2, priorities of the split frequency bands are decided respectively, and a quantization method of each frequency band is determined according to the priorities for each of the frequency bands. In operation 1003, the plurality of signals with the different frequency bands are subjected to DCT using the band priority information and the energy information of the low-band signal by the band signal quantization module 207 of FIG. 2, thereby obtaining first DCT coefficients. The magnitudes and signs of the first DCT coefficients are extracted independently. In operation 1004, the magnitudes of the first DCT coefficients are subjected to DCT, thereby obtaining second DCT coefficients. Each of the second DCT coefficients is divided into a DC component (DC value) and a third DCT coefficient. In operation 1005, the DC value and third DCT coefficient of the second DCT coefficient are quantized independently. At this time, the DC value is quantized using an inter-band prediction method, and the RMS value of the third DCT coefficient is quantized using a quantized DC value by an intra-band prediction quantization method. In operation 1006, the first DCT coefficient sign is quantized and transmitted. At this time, a sign of a DCT coefficient with a large magnitude is detected and transmitted with reference to the magnitude order information of the first quantized DCT coefficients. If a low-band speech packet and a high-band speech packet compressed with a scalable bandwidth structure are received, the wide-band speech signal decompression method according to this embodiment of the present invention decompresses a low-band speech packet to a low-band speech signal as seen in FIG. 7, and decompresses the high-band speech packet to the high-band speech signal using the energy information of the decompressed low-band signal obtained when decompressing the low-band speech signal. FIG. 11 is a flowchart illustrating a process for decompressing the high-band speech signal using the wide-band speech signal compression method according to this embodiment of the present invention. If a high-band speech packet is received via a communication channel (not shown), the high-band speech packet received in operation 1101 is dequantized according to the respective modules, and the magnitudes of the first dequantized DCT coefficients are obtained. In operation 1102, the signs of the received first DCT coefficients are respectively inserted into the corresponding DCT coefficients according to the magnitude order information of the first quantized DCT coefficients, as described in FIG. 8. In operation 1103, signs of the first DCT coefficients which are not received are predicted by the sign predictor module 822 of FIG. 8, and the predicted signs are inserted into the corresponding first quantized DCT coefficients. In operation 1104, a time-domain signal for each band is obtained through an inverse DCT for the first quantized DCT coefficients, and a finally decompressed high-band speech signal is output by the filter bank 826 of FIG. 8. Meanwhile, the high-band speech signal decompressed using the method shown in FIG. 11 is combined with the low-band speech signal decompressed using the method described in FIG. 7 to generate a wide-band decompressed signal. As described above, according to the present invention, there is provided a wide-band speech signal compression apparatus with a scalable bandwidth structure, compatible with an existing standard narrow-band speech compressor, and a wide-band speech signal decompression apparatus thereof. Also, according to the present invention, it is possible to improve quantization efficiency by utilizing energy of a low-band signal detected when compressing a high-band speech signal and using correlation of intra-band and inter-band. Also, according to the present invention, it is possible to efficiently perform quantization and prediction by quantizing DCT coefficients according to their magnitudes and signs, selectively performing quantizations of the signs according to the magnitudes of the DCT coefficients, and predicting non-transmitted signs in decompressing. Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to encoding and decoding of a speech signal, and, more particularly, to a wide-band speech signal compression apparatus to compress a speech signal in a scalable bandwidth structure, a wide-band speech signal decompression apparatus to decompress the compressed speech signal, and a method thereof. 2. Description of the Related Art An existing communication method based on Public Switched Telephone Network (PSTN) samples a speech signal at 8 kHz and transmits a speech signal with a bandwidth of 4 kHz. Accordingly, such a PSTN-based communication method cannot transmit speech signals of a frequency beyond 4 kHz, which deteriorates the voice quality of the speech signal. To solve such a problem, a packet-based wide-band speech signal compression apparatus that samples a received speech signal at 16 kHz, and provides a speech signal with a bandwidth of 8 kHz, has been developed. However, although the quality of the speech signal improves as the bandwidth of the speech signal increases, the amount of data transmission of the communication channel increases. Therefore, to efficiently operate the wide-band speech signal compression apparatus, an adequate communication channel for transmitting large amounts of data should be ensured. However, the amount of data transmission on the packet-based communication channel may be changed according to various factors. Accordingly, the adequate communication channel required by the wide-band speech signal compression apparatus may not be ensured, which can deteriorate the voice quality of the speech signal. That is, if the amount of data transmission on the communication channel is not enough at a specific moment, the speech packet is lost during transmission, so that the speech signal cannot be transmitted. Accordingly, a technique which compresses speech signals by a scalable bandwidth has been proposed. An example of such a technique is ITU standard G.722. The ITU standard G.722 proposes a method that divides a received speech signal into two bands, using a low-pass filter and a high-pass filter, and compresses the respective bands individually. In the ITU standard G.722, the signals are compressed according to an Adaptive Differential Pulse Sign Modulation (ADPCM) method. However, the compression method proposed in the ITU standard G.722 has a very high data transmission rate. Also, the ITU standard G.722.1 discloses a technique that converts a wide-band signal into a frequency-domain signal, divides the frequency-domain signal into several sub-band signals, and compresses the respective sub-band signals. However, the ITU standard G.722.1 is not compatible with a standard narrow-band speech signal compression apparatus, and it also does not construct a speech packet in a scalable bandwidth structure. A conventional wide-band speech signal compression technique, developed to be compatible with a standard narrow-band speech signal compression apparatus, passes a wide-band speech signal through a low-pass filter to obtain a narrow-band speech signal, encodes the narrow-band speech signal using a standard narrow-band speech signal compressor, and compresses a high-band speech signal using a separate method. Here, packets of the narrow-band speech signal and the high-band speech signal are transmitted in a scalable structure. A conventional technique for processing a high-band speech signal divides a high-band speech signal into a plurality of sub-band signals using a filter-bank, and compresses the respective sub-band signals. Another conventional technique for compressing a high-band speech signal converts the high-band speech signal into a frequency-domain signal by discrete cosine transform (DCT) or discrete Fourier transform (DFT) and quantizes the generated frequency coefficients individually. However, since such wide-band speech signal compression techniques having a scalable bandwidth structure do not use the characteristics of the narrow-band speech signal when compressing the high-band speech signal, they have a low compression efficiency. Also, since these wide-band speech signal compression techniques quantize all frequency coefficients converted to a frequency domain without efficient use of the correlation of intra-band and inter-band, they have a low quantization efficiency and a low prediction performance in decompressing information not transmitted when the signal was compressed. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a wide-band speech signal compression apparatus that is compatible with a conventional standard narrow-band speech signal compressor, a wide-band speech signal decompression apparatus, and a method thereof. The present invention also provides a wide-band speech signal compression apparatus and a wide-band speech signal decompression apparatus to compress a high-band speech signal using compression information of a low-band speech signal and decompress the compressed speech signal, when compressing and decompressing a speech signal using a scalable bandwidth structure, respectively, and a method thereof. The present invention also provides a wide-band speech signal compression apparatus and a wide-band speech signal decompression apparatus to compress a high-band speech signal using a correlation of inter-band and intra-band and decompress the compressed high-band speech signal, and a method thereof. The present invention also provides a wide-band speech signal compression apparatus and a wide-band speech signal decompression apparatus to respectively quantize frequency coefficients, obtained by converting speech signals to frequency domain signals, differently according to the characteristics of frequency coefficients and their bands when compressing the speech signals, and decompress the compressed speech signals, and a method thereof. The present invention also provides a speech decompression apparatus to minimize information loss in decompressing, by predicting information not transmitted due to compression by a speech compressor apparatus, and a method thereof. Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. According to an aspect of the present invention, there is provided an apparatus to compress a wide-band speech signal, the apparatus comprising: a narrow-band speech compressor to compress a low-band speech signal of the wide-band speech signal and output the compressed low-band speech signal as a low-band speech packet; and a high-band speech compressor to compress a high-band speech signal of the wide-band speech signal using energy information of the low-band speech signal provided from the narrow-band speech compressor, and outputs the compressed high-band speech signal as a high-band speech packet. According to another aspect of the present invention, there is provided an apparatus to decompress a wide-band speech signal, the wide-band speech signal including a compressed low-band speech packet and a compressed high-band speech packet, the apparatus comprising: a narrow-band speech decompressor to decompress the compressed low-band speech packet into a low-band speech signal; a high-band speech decompressor to decompress the compressed high-band speech packet into a high-band speech signal using energy information of the decompressed low-band speech signal provided from the narrow-band speech decompressor; and an adder to add the low-band speech signal output from the narrow-band speech decompressor with the high-band speech signal output from the high-band speech decompressor and output the decompressed wide band speech signal. According to still another aspect of the present invention, there is provided a method of compressing a wide-band speech signal, the method comprising: receiving the wide-band speech signal and compressing a high-band speech signal of the wide-band speech signal using energy of a low-band signal of the wide-band speech signal; and outputting the compressed high-band speech signal as a high-band speech packet. According to still yet another aspect of the present invention, there is provided a method of decompressing a compressed wide-band speech signal having a high-band speech packet and a low-band speech packet being compressed with a scalable bandwidth structure, the method comprising: decompressing the low-band speech packet into a low-band speech signal; decompressing the high-band speech packet into a high-band speech signal using energy information of the decompressed low-band speech signal obtained in the decompressing of the low-band speech signal; and adding the low-band speech signal with the high-band speech signal and generating a wide-band decompression signal. | 20040715 | 20130430 | 20050203 | 94151.0 | 0 | NEWAY, SAMUEL G | Wide-band speech signal compression and decompression apparatus, and method thereof | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,891,569 | ACCEPTED | Process for fabricating non-volatile memory by tilt-angle ion implantation | A potassium/sodium ion sensing device applying an extended-gate field effect transistor, which using an extended-gate ion sensitive field effect transistor (EGFET) as base to fabricate a potassium/sodium ion sensing device, using the extended gate of the extended-gate ion sensitive field effect transistor as a signal intercept electrode, and immobilizing the hydro-aliphatic urethane diacrylate (EB2001) intermixed with electronegative additive, potassium ionophore, sodium ionophore, and the like, to fabricate a potassium/sodium ion sensing electrode. The present invention utilizes the photocurability and good hydrophilicity of the hydro-aliphatic urethane diacrylate (EB2001), and fixes potassium/sodium ionophore, can obtain a non-wave filter, single-layer, stable signal potassium and sodium ion sensor. Thus, when the present invention is applied to measure the concentration of potassium/sodium ions in a sample, the mutual interference between potassium/sodium ion electrodes can be reduced, so the measured value can be more close to the actual value. | 1. A potassium/sodium ion sensing device applying an extended-gate field effect transistor, comprising: a glass substrate; an indium tin oxide (ITO) film located on said glass substrate and totally overlaying the top of said glass substrate; a tin oxide (SnO2) film located on the top of said glass substrate forming a sensing membrane which an end of said sensing membrane does not cover said ITO film; a silver paste adhering to said ITO film at the end of said SnO2 film uncovered by said ITO film; a conducting wire which an end of said conducting wire encapsulated said silver paste and another end of said conducting wire is drawn to outside; a sealing layer which covering said conducting wire and said silver paste and exposing said SnO2 film to form a sensing window and; a polymer ion selective membrane located in said sensing window of said SnO2 film. 2. The potassium/sodium ion sensing device applying an extended-gate field effect transistor as recited in claim 1, wherein the sensing window is a square window. 3. The potassium/sodium ion sensing device applying an extended-gate field effect transistor as recited in claim 1, wherein the plated film thickness of said SnO2 film is about 2000 Å. 4. The potassium/sodium ion sensing device applying an extended-gate field effect transistor as recited in claim 1, wherein the capacity of said polymer ion selective membrane in the sensing window is 3 μl. 5. The potassium/sodium ion sensing device applying an extended-gate field effect transistor as recited in claim 1, wherein the material of said sealing layer is epoxy resin. 6. The potassium/sodium ion sensing device applying an extended-gate field effect transistor as recited in claim 1, wherein said silver paste is being immobilized between said ITO film and said conducting wire to form a conductive channel. 7. A manufacturing method of a potassium/sodium ion sensing device applying an extended-gate field effect transistor, the method comprising the steps of: Step 1: depositing a SnO2 film on an ITO glass substrate as a solid-state sensing substrate; Step 2: adhering a silver paste to said ITO glass substrate and a conducting wire; Step 3: using epoxy resin to seal said silver paste and said conducting wire, and to package a sensing window; Step 4: immobilizing a polymer ion selective membrane in said sensing window. 8. The manufacturing method as recited in claim 7, wherein said ITO glass substrate that an ITO film with thickness 230 Å and resistance 50.100Ω/□ is provided on a glass substrate. 9. The manufacturing method as recited in claim 7, wherein using sputtering to grow a SnO2 film, SnO2 as target, introducing a mixed gas that the ratio to grow a SnO2 film, SnO2 as target, introducing a mixed gas that the ratio of argon to oxygen is 4:1. 10. The manufacturing method as recited in claim 7, wherein maintaining the temperature of said ITO glass substrate to be 150° C., deposition pressure 20 mtorr, radio-frequency power 50 W, plated film thickness 2000 Å during growing said SnO2 film. 11. The manufacturing method as recited in claim 7, wherein said potassium/sodium ion sensing device applying an extended-gate field effect transistor is cleaned by methyl alcohol for 15 minutes, de-ionized water for 15 minutes, uses said silver paste to immobilize said conducting wire, and then is baked for 30 minutes at 150° C. 12. The manufacturing method as recited in claim 7, wherein said potassium/sodium ion sensing device applying an extended-gate field effect transistor is sealed with epoxy resin, and is baked for 10 minutes at 150° C. 13. The manufacturing method as recited in claim 7 wherein said polymer ion selective membrane includes a photo-curable polymer, a photo-initiator, an electronegative additive, a potassium ionophore or sodium ionophore, which a method for fabricating an ion selective membrane comprising the steps of: Step 1: intermixing a hydro-aliphatic urethane diacrylate (EB2001) with a photo-initiator; Step 2: adding a photo-curable polymer into the mixture of step 1 and intermixing in an ultrasonic bath; Step 3: adding a potassium ionophore or sodium ionophore, an electronegative additive into the mixture of step 2; Step 4: intermixing the mixture of step 3 in an ultrasonic bath. 14. The manufacturing method of claim 13, wherein the ratio of the hydro-aliphatic urethane diacrylate (EB2001) to the photo-initiator is 100:2 (w/w). 15. The manufacturing method of claim 13, wherein said photo-curable polymer placed in the ultrasonic bath is mixed for 30 minutes. 16. The manufacturing method of claim 13, wherein the ratio between said hydro-aliphatic urethane diacrylate (EB2001) and said potassium ionophore and said electronegative potassium ion complex is 33:6:3 (w/w). 17. The manufacturing method of claim 13, wherein the ratio between said hydro-aliphatic urethane diacrylate (EB2001) and said sodium ionophore and said electronegative sodium ion complex is 33:4:2.4 (w/w). 18. The manufacturing method of claim 13, wherein intermixing said hydro-aliphatic urethane diacrylate (EB2001) with said potassium ionophore and said electronegative potassium ion complex and placed in an ultrasonic bath, heating in a 30° C. water separation tank, oscillating and mixing for 1 hour. 19. A measuring method of a potassium/sodium ion sensing device applying an extended-gate field effect transistor, the measuring method comprising the steps of: Step 1: designing a single amplifier as a readout circuit; Step 2: connecting a positive input of said amplifier to a potassium ion selective electrode of a potassium/sodium ion sensing device, applying an extended-gate field effect transistor or a sodium ion selective electrode of a potassium/sodium ion sensing device, and applying an extended-gate field effect transistor; Step 3: connecting a negative input of said amplifier to a glass electrode; Step 4: using said potassium ion selective electrode of said potassium/sodium ion sensing device applying an extended-gate field effect transistor to measure a potassium ion test solution; Step 5: using said sodium ion selective electrode of said potassium/sodium ion sensing device applying an extended-gate field effect transistor to measure a sodium ion test solution; 20. The measuring method of claim 19, wherein the readout circuit is a single amplifier that the potentials of VDD and VSS are 9V and −9V respectively and the negative input of said single amplifier is grounded and said single amplifier has no feedback circuit. 21. The measuring method of claim 19, wherein the positive input of said amplifier connects to said potassium ion selective electrode or said sodium ion selective electrode. 22. The measuring method of claim 19, wherein the negative input of said amplifier is grounded and connected to an Ag/AgCl reference electrode. 23. The measuring method of claim 19, wherein a solution of Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, is used to prepare 5 bottles of KCL that each has concentration pK1, pK2, pK3, pK4, pK5 and is measured in a sequence as pK5, pK4, pK3, pK2, pK1. 24. The measuring method of claim 19, wherein a solution of Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, is used to prepare 5 bottles of NaCl that each has concentration pNa0, pNa1, pNa2, pNa3, pNa4 and is measured in a sequence as pNa4, pNa3, pNa2, pNa1, pNa0. 25. The measuring method of claim 19, wherein the range of said potassium ion test solution for detecting concentration is pK1-pK5, detection limit is pK4, and the selective potential within detection range is 55.06 (mV/pK) 26. The measuring method of claim 19, wherein the range of sodium ion test solution for detecting concentration is pNa0.1-pNa2, detection limit is pNa2, and the selective potential within detection range is 53.14 (mV/pNa). 27. The measuring method of claim 19, wherein a hydro-aliphatic urethane diacrylate (EB2001) is a polymer immobilized substrate and it encapsulates a potassium/sodium ionophore to obtain a single-layer polymer ion selective membrane. 28. The measuring method of claim 19, wherein an encapsulating method of a hydro-aliphatic urethane diacrylate (EB2001) as a polymer immobilized substrate does not require a back-end wave filter circuit. 29. A correction method of a potassium/sodium ion sensing device applying an extended-gate field effect transistor, the correction method comprising the steps of: Step 1: measuring a correction curve of a potassium ion selective electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor; Step 2: measuring a correction curve of a sodium ion selective electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor; Step 3: measuring the output potential of said potassium ion selective electrode in a mixed solution of potassium and sodium; Step 4: measuring the output potential of said sodium ion selective electrode in a mixed solution of potassium and sodium; Step 5: using said potassium ion correction curve and said measured output potential of a potassium ion selective electrode in a mixed solution of potassium and sodium to satisfy the equation: 10E-constant/m=aK−KK,NapotaNa; Step 6: using said sodium ion correction curve and said measured output potential of a sodium ion selective electrode in a mixed solution of potassium and sodium to satisfy the equation: 10E-constant/m=aNa−KNa,KpotaK; Step 7: using the above two equations to determine jointly corrected concentrations of potassium and sodium ion. 30. The correcting method of claim 29, wherein a solution of Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, is used to prepare 5 bottles of KCl that each has concentration pK1, pK2, pK3, pK4, pK5, and is measured by said potassium ion selective electrode to obtain a correction curve. 31. The correcting method of claim 29, wherein a solution of Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, is used to prepare 5 bottles of NaCl that each has concentration pNa0, p Na1, p Na2, p Na3, p Na4, and is measured by said sodium ion selective electrode to obtain a correction curve. 32. The correcting method of claim 29, wherein a solution of Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, is used o prepare NaCl 1 M and KCl 0.05M in a bottle, and is measured by said potassium ion selective electrode to obtain a potassium ion electrode output potential, and is measured by said sodium ion selective electrode to obtain a sodium ion electrode output potential. 33. The correcting method of claim 29, wherein four parameters of equation 10E-constant/m=aK−KK,NapotaNa are: the constant and the slope (m) obtained from the correction curve of said potassium ion selective electrode, the output potential (E) of said potassium ion electrode of said measured potassium/sodium mixed solution, and an interference parameter of potassium ion potential (KK,Napot). 34. The correcting method of claim 29, wherein four parameters of equation 10E-constant/m=aNa−KNa,KpotaK are: the constant and the slope (m) obtained from the correction curve of said sodium ion selective electrode, an output potential (E) of said sodium ion electrode of said measured potassium/sodium mixed solution, and an interference parameter of sodium ion potential (KNa,Kpot). 35. The correcting method of claim 29, wherein said sodium ion selective electrode is used to correct said potassium ion selective electrode that the error rate of said potassium ion selective electrode is corrected from 39.8% to 4%. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a potassium/sodium ion sensing device applying an extended-gate field effect transistor, particularly to a potassium/sodium ion sensing device applying an extended-gate field effect transistor which uses an ion interference for mutual correction to obtain more accurate values. Therefore, the present invention can be applied to industries such as medical examinations, biomedical materials, and semiconductor device fabrications, etc. 2. Description of the Prior Art As compared with conventional ion selective glass electrodes, at present the solid-state electrode has more advantages, such as low cost, easy miniaturization and durability, non-breakable, etc., therefore the market share is tend to ripe semiconductor integration of field effect transistor substitute for conventional glass electrode. [P. Bergveld, “Development of an ion-sensitive solid-state device for neurophysiological measurements”, IEEE Transactions on Biomedical Engineering, BME-17, pp. 70-71, 1970]. The fluid of a human body can be classified to extra-cellular and intra-cellular fluids, wherein primary ions include sodium, potassium, calcium, etc.; the balance of sodium ion and potassium ion is important particularly. In the normal condition of a human body, the concentration of sodium/potassium ions is stable, the normal value of serum potassium is 3.5-5.0 mM (avg. 4.3 mM), the normal value of serum sodium is 135-145 mM (avg. 140 mM) [pp. 847-900, Sec. 2 Examination, The Clinical Internal Medicine, BOR-SHEN HSIEH, published by Golden Name Press, 1990.] Thus, sodium is a major cation in the extra-cellular fluid of a human body, 98% ion is sodium ion in all extracellular, and 2% ion is sodium ion in all intra-cellular. The potassium and sodium ion concentration will change if a patient has kidney failure or dehydration, thus the doctor can use the unbalance condition of sodium/potassium ions to examine the disease of the human body. The determination of content of sodium/potassium ions in the human body is generally performed by polarographic method, atomic absorption spectrometry (AAS), and the like which need pre-processing and operating inconveniently. Those current commercial pH/sodium/potassium ion electrodes often have errors when used to measure the environment of interfering ion more than the measured ion (that is, the extra-cellular and intra-cellular fluids in the human body). Thus, in order to remove the interference from various ions on electrodes, it is required to measure the ions having greater effects in the solution simultaneously. Patents related to the conventional technology are described as follows: (1) Inventor: D. C. Chan Andy, Patent Number: U.S. Pat. No. 6,416,646; Date of patent: Jul. 9, 2002, Title: “Method of making a material for establishing solid state contact for ion selective electrodes”. This cited reference discloses a polymeric material, a methacrylamidopropyltrimethyl-ammoniumchloride (MAPTAC) or methyllmethacrylate (MMA), applied on the gate of a field effect transistor to fabricate an ion selective electrode, which is stable and reproducible, and polymeric membrane mixable with ion selective material being incorporated in a solid-state electrode; The electric charge of the polymer described in the cited reference is 2.72 mEq/g (millaequivalents/gram), and the polymeric material recited in the claims includes immobilized sites of charge opposite that of mobile ions involved in the redox couple. (2) Inventor: Martijn Marcus Gabriel Antonisse, David Nicolaas Reinhoudt, Bianca Henriette Maria Snellink-Ruel, Peter Timmerman, Patent Nubmer: U.S. Pat. No. 6,468,406. Date of patent. Oct. 22, 2002, Title: “Anion-complexing compound, method of preparing the same, an ion-selective membrane and a sensor provided with such a compound or membrane”. This cited reference discloses the synthesis and application of an ion selective material of alkali and alkaline earth group, using organic synthesis, to prepare compounds with specific functional group; such as —NHC(X)—, —C(X)NH—, —NHC(X)NH—, wherein X includes sulfur or oxygen atom, with its specific compound structure, to achieve the effect for selecting an ion selective material of alkali and alkaline earth group; the cited reference also discloses, adding on a polymer to encapsulate an ion selective material, to prepare an extended gate ion selective electrode. (3) Inventor: Massimo Battilotti, Giuseppina Mazzamurro, Matteo Giongo, Invent Number: U.S. Pat. No. 5,130,265. Date of patent. Dec. 21, 1989, Title: “Process for obtaining a multifunctional, ion-selective-membrane sensor using a siloxanic prepolymer”. This cited reference discloses a process, using a photocurable polymer, to achieve fixing various ion selective materials on a microelement. A claimed process of a sensing device, which using a solvent with a photoinitiator to solve silica and an ion selective material, applied to a substrate in liquid using spinning, and then exposed with appropriate ultraviolet light, after cleaned by an organic solvent, hardening the polymer by heating, and repeating the above, to obtain a sensing electrode in the same substrate, and thus making various ion field effect transistor sensing devices. (4) Inventor: Akihiko Mochizuki, Hideyo lida, Patent Nubmer: U.S. Pat. No. 4,921,591. Date of patent. May 1, 1990, Title: “Ion sensors and their divided parts”. This cited reference discloses an ion selective membrane, includes a vinyl polymer based compound containing a hydroxyl and/or carboxyl group, fixed on an extended gate sensitive field effect transistor. In the claims, it also discloses a reference electrode arranged in the opposite side of a ion selective electrode. The ion selective electrode and reference electrode are separate. The materials of reference electrode is different with the extended gate. (5) Inventor: Noboru Oyama, Takeshi Shimomura, Shuichiro Yamaguchi, Patent Number: U.S. Pat. No. 4,816,118. Date of patent. Mar. 28, 1989, Title: “Ion-sensitive FET sensor”. This cited reference discloses an ion selective electrode (ISFET), the gate of MOSFET is pulled out, and an ion selective membrane is added; wherein a redox layer having a redox function is provided between the isolating membrane and the ion-sensitive layer to improve operating stability and speed of response; an electrically conductive layer or a combination of a metal film and an electrically conductive layer is provided between the isolating membrane and the redox layer to further improve operating stability, the adhesion of the layers and the durability of the sensor. Also disclosed are optimum materials for use as an ion carrier employed in the ion-sensitive layer. (6) Inventor: D. N. Reinhoudt, M. L. M. Pennings, A. G. Talma, Paten Number: U.S. Pat. No. 4,735,702. Date of patent. Apr. 5, 1988, Title: “Method of producing an ISFET and same ISFET”. This cited reference discloses: a method of modifying an oxide surface of a semi-conductor material, incorporated for example in an ISFET, in which a polymer coating is applied to the oxide surface. This cited reference also describes: using a modified polymer to fix oxide functional group to the gate of a field effect transistor or to introduce a metal complex into a polymer, and thus to achieve a product for mass production. Furthermore, since the miniaturization of an optical ion sensor is difficult, although electrical ion sensor can use an integrated circuit process to achieve miniaturization, the sensitive potential signal is subjected to the ion movement in the solution to produce noise. In order to stabilize the potential signal or improve potential interference, generally can add a filter circuit at the back end circuit, or as the above-cited reference (1)-(6), can change the feature of polymer of the ion selective membrane. And, according to the literatures: [IUPAC, “Recommendations for nomenclature of ion-selective electrodes”, Pure and Applied Chemistry, Vol. 66, pp. 2527-2536, 1994. R. Eugster, P. M. Gehrig, W. E. Morf, U. E. Spichiger, and W. Simon, “Selectivity-modifying influence of anionic sites in neutral carrier-based membrane electrodes”, Analytical Chemistry, Vol. 63, pp. 2285-2289, 1991.M. Yanming and E. Bakker, “Determination of complex formation constants of lipophilic neutral ionophores in solvent polymeric membranes with Segmented sandwich membranes”, Analytical Chemistry, Vol. 71, pp. 5279-5287, 1999. S. Amemiya, P. Bulhlmann, E. Pretsch, B. Rusterholz, Y. Umezawa, “Cationic or anionic Sites-selectivity optimization of ion-selective electrodes based on charged ionophores”, Analytical Chemistry, Vol. 72, pp. 1618-1631, 2000.E. Bakker, E. Pretsch, “Ion-selective electrodes based on two competitive ionophores for determining effective stability constants of ion-carrier complexes in solvent polymeric membranes”, Analytical Chemistry, Vol. 70, pp. 395-302, 1998. F. Deyhimi, “A method for the determination of potentiometric selectivity coefficients of ion selective electrodes in the presence of several interfering ions”, Talanta, Vol. 50 (5), pp. 1129-1134, 1999. E. Bakker, “Origin of anion response of solvent polymeric membrane based silver ion-selective electrodes”, Sensors and Actuators B, Vol. 35 (1-3), pp. 20-25, 1996. P. Kane, D. Diamond, “Determination of ion-selective electrode characteristics by non-linear curve fitting”, Talanta, Vol. 44, pp. 1847-1858, 1997], ion interference is: when the solution to be tested contains other ion not to be tested, the amount of the ion not to be tested can affect the output potential, so the output potential can not indicate correct concentration of the ion to be tested. However, using polymer for fixing is a special subject, different polymers will affect the ion diffusivity and ionophore encapsulatement [C. P. Hauser, W. L. D. Chiang, A. W. Graham, “A potassium ion selective electrode with valinomycin based poly (vinyl chloride) membrane and a poly (vinyl ferrocene) solid contact”, Analytical Chimica Acta., Vol. 302, pp. 241-248, 1995. B. Andrey, A. Nataliya, M. Javier, D. Carlos, “Optimization of photocurable polyurethane membrane composition for ammonium ion sensor”, Journal of Electrochemical Soc., Vol. 144 (2), pp. 617-621, 1997. Y. H. Lee, A. H. Hall Elizabeth, “Methacrylate-acrylate based polymers of low plasticiser cont for potassium ion-selective membranes” Analytical Chemica Acta., Vol. 324, pp. 47-56, 1996. B. Jundrey, A. Nataliya, M. Javier, D. Carlos, A. Salvador, B. Jordi “Photocureable polymer matrices for potassium-sensitive ion selective electrode membranes” Analytical Chemistry, Vol. 67, pp. 3589-3595, 1995. Yook-Heng Lee, A. H. Elizabeth, “Assessing a photocured self-plasticised acrylic membrane recipe for Na and K ion selective electrodes”, Analytica Chimica Acta, Vol. 443, pp. 25-40, 2001. K. J. Shinichi, M. S. Arakawa, S. Michiko, O. Tetsuya, S. lkuo, “Flow injection analysis of potassium using an all-solid-state potassium selective electrode as a detector”, Talanta, Vol. 46, pp. 1293-1297, 1998. P. C. Pandey, R. Prakash, “Polyiudole modified potassium ion sensor using dibenzo-18-crown-6 mediated PVC matrix membrane”, Sensors and Actuators B, Vol. 46, pp. 61-65, 1998. M. J. Roger, P. J. S. Barbeiva, A. F. B. Sene, N. R. Stradiotto, “Potentiometria determination of potassium cations using a nickel(II)hexacyanofereate-modified electrode”, Talanta, Vol. 49, pp. 271-275, 1999]. The amount of negative charge ionophore and additive influence the potentiometric selectivity coefficient in potassium/sodium ion electrodes [R. Eugster, P. M. Gehrig, W. E. Morf, U. E. Spichiger, and W. Simon, “Selectivity-modifying influence of anionic sites in neutral carrier-based membrane electrodes”, Analytical Chemistry, Vol. 63, pp. 2285-2289, 1991. S. Amemiya, P. Bulhlmann, E. Pretsch, B. Rusterholz, Y. Umezawa, “Cationic or anionic Sites-selectivity optimization of ion-selective electrodes based on charged ionophores”, Analytical Chemistry, Vol. 72, pp. 1618-1631, 2000], in a potassium/sodium ion sensor, if the ionosphere or electronegative additive is larger than a certain amount, the positive charge of other ions to be tested will be affected by electronegativity. Addressing to the problem of potential interference, the International Union of Pure and Applied Chemistry (IUPAC) had recommended the potential interference parameters of a potentiometric sensor [IUPAC, “Recommendations for nomenclature of ion-selective electrodes”, Pure & Applied Chemistry, Vol. 66, pp. 2527-2536, 1994], potantiometric selectivity coefficient can input The Nikolsky-Eisenman equation to obtain more accurate potassium/sodium ion concentration in practice. Accordingly, it can be seen that the above-described conventional technique still has many drawbacks, are not designed well, and thus need to be improved. In view of disadvantages derived from the above-described conventional techniques, the present inventor had devoted to improve and innovate, and, after studying intensively for many years, developed successfully a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the invention. SUMMARY OF THE INVENTION The object of the invention is to provide a potassium/sodium ion sensing device applying an extended-gate field effect transistor that uses the hydro-aliphatic urethane diacrylate (EB2001) as immobile material capable of simplifying a process for fabricating an ion selective membrane to obtain a single layer membrane potassium/sodium ion sensor without an add-on wave filter circuit. A further object of the present invention is to provide a potassium/sodium ion sensing device applying an extended-gate field effect transistor that uses a process which comprising: use realized tin oxide (SnO2) as substrate and then is adhered with potassium/sodium ion selective membrane, measure the concentration potential of each ion, input known potentiometric sensitivity coefficient to the Nikolsky-Eisenman equation to reduce interference, and obtain the actual value. Another object of the present invention is to provide a potassium/sodium ion sensing device applying an extended-gate field effect transistor with a fabrication method possessing advantages such as simple equipment, low cost, mass production, etc., thus the potassium ion and sodium ion sensing device according to the present invention has high feasibility and high applicability. The potassium/sodium ion sensing device applying an extended-gate field effect transistor capable of achieving the above-mentioned objects, based on an extended-gate ion sensitive field effect transistor, using the extended gate of the extended-gate ion sensitive field effect transistor as a signal intercept electrode, and immobilizing the hydro-aliphatic urethane diacrylate (EB2001) intermixed with electronegative additive, ionophores such as potassium, sodium, etc., to fabricate a potassium/sodium ion sensing electrode. The present invention utilizes the photocurability and good hydrophilicity of the hydro-aliphatic urethane diacrylate (EB2001), and fixes potassium/sodium ionophore, can obtain a non-wave filter, single-layer, stable signal potassium and sodium ion sensor. Thus, when the present invention is applied to measure the concentration of potassium/sodium ions in a sample solution, the mutual interference between potassium/sodium ion electrodes can be reduced, so the measured value can be more close to the actual value. These features and advantages of the present invention will be fully understood and appreciated from the following detailed description of the accompanying Drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a process diagram of an extended-gate substrate of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention; FIG. 2 shows a processing diagram of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention which the hydro-aliphatic urethane diacrylate (EB2001) intermixes with ionophores; FIG. 3 shows the diagram of the steps for immobilizing a polymer ion selective membrane of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention; FIG. 4 shows the cross section view of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention after immobilizing an ion selective membrane to a SnO2/ITO/glass sensing architecture; FIG. 5 shows the measurement architecture diagram of a potassium/sodium ion sensing electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention; FIG. 6 shows a potential vs. time relationship diagram of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention which using the hydro-aliphatic urethane diacrylate (EB2001) to encapsulate a potassium ionophore to measure a potassium ion buffer solution; FIG. 7 shows a potential vs. time relationship diagram of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention which using the hydro-aliphatic urethane diacrylate (EB2001) to encapsulate a sodium ionophore to measure a sodium ion buffer solution; FIG. 8 shows a measured signal diagram of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention in which the concentration range of the potassium ion is between pK1-pK5 after a potassium ionophore is intermixed with the hydro-aliphatic urethane diacrylate (EB2001) 33 mg; FIG. 9 shows a measured signal diagram of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention in which the concentration range of the sodium ion is between pNa0-pNa4 after a sodium ionophore is intermixed with the hydro-aliphatic urethane diacrylate (EB2001) 33 mg; FIG. 10 shows the correction curve plot of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention which using a potassium ion electrode to measure a KCL (pK0-3) solution; FIG. 11 shows the correction curve plot of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention which using a sodium ion electrode to measure a NaCl (pNa0-3) solution; and FIG. 12 shows the output potential plot which a potassium ion electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention is used to measure an unknown (pNa 1, pK 1.3) solution; and FIG. 13 shows the output potential plot which a sodium ion electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention is used to measure an unknown (pNa 1, pK 1.3) solution; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The process steps of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention are described as follows: Step 1: Fabricating SnO2 solid-state film: As shown in FIG. 1, the ITO film (12) of a commercialized glass substrate (13) which has thickness 230 Å, resistance 50.100 Ω/□; wherein the conditions for fabricating a SnO2 film are: using sputtering to grow a SnO2 film (11), SnO2 as target, introducing a mixed gas which the ratio of Argon and oxygen is 4:1, during growing a SnO2 film (11), keeping the temperature of the substrate on 150° C., deposition pressure 20 mtorr, radio-frequency power 50 W, plated film thickness 2000 Å; Step 2: Fabricating a SnO2/ITO glass extended sensing electrode: clearing the device (1) with methyl alcohol for 15 minutes, de-ionized water for 15 minutes, and using silver paste (14) to immobilize the conducting wire (15), and then baking for 30 minutes at 150° C., and finally sealed by the epoxy resin (17). Opening a 4 mm2 sensing window (16), and again baking for 15 minutes at 150° C.; Step 3: Fabricating a potassium ion selective electrode: As shown in FIG. 2, intermixing the hydro-aliphatic urethane diacrylate (EB2001) 1 g with photoinitiator (TPO) 0.02 g and tetrahydrofuran (THF) 1 ml, oscillated for 30 minutes by a ultrasonic bath (21); extracting a polymer solution 33 μl (33 mg) to mix with a potassium ionophore (valinomycin) 6 mg and a electronegative potassium ion complex (Potassium terakis(p-chlorophenyl) borate) 3 mg and are placed into a test tube as a polymer ion selective membrane mixture (23), and heating with a water (22) separation tank, oscillated for 60 minutes by an ultrasonic bath (21); subsequently, as shown in FIG. 3, extracting a polymer ion selective membrane mixture (23) 3 μl to be immobilized on the sensing window (16) of SnO2/ITO glass pH sensing electrode, and thus obtaining a polymer ion selective electrode; still for 10 minutes, after tetrahydrofuran (THF) evaporated to stabilize the immobilized polymer ion selective membrane (18), placed into a UV cabinet (3), keeping 5 cm away from light-tube, photocuring 60 seconds with wave length 350 nm/96 W. Step 4: Fabricating a sodium ion selective electrode: As shown in FIG. 2, intermixing hydro-aliphatic urethane diacrylate (EB2001) 1 g with photoinitiator (TPO) 0.02 g and tetrahydrofuran (THF) 1 ml, oscillated for 30 minutes by an ultrasonic bath (21); extracting a polymer solution 33 μl (33 mg) to mix with a sodium ionophore {Bis[(12-crown-4)-methyl]-dodecylmethyl malonate}4 mg and a electronegative sodium ion complex (Sodium tetrakis(4-fluorophenyl)borate dihydrate) 2.4 mg and are placed into a test tube as a polymer ion selective membrane mixture (23), and heating with a water (22) separation tank, oscillated for 60 minutes by a ultrasonic bath (21); subsequently, as shown in FIG. 3, extracting a polymer ion selective membrane mixture (23) 3 μl to be immobilized on the sensing window (16) of SnO2/ITO glass pH sensing electrode, and thus obtaining a polymer ion selective membrane; still for 10 minutes, after tetrahydrofuran (THF) evaporated to stabilize the immobilized polymer ion selective membrane (18), placed into a UV cabinet (3), keeping 5 cm away from light-tube, photocuring for 180 seconds with wave length 350 nm/96 W. Step 5: As shown in FIG. 4, the architecture of a potassium/sodium ion selective electrode is: depositing a ITO film (41) on a glass substrate (40), fixing a conducting wire (42) on the ITO film (41), depositing a SnO2 film (43) on the ITO film (41), sealing with epoxy resin (44), fixed a window(4 mm2) by a potassium/sodium ion selective membrane (45), and thus achieving an architecture of a potassium/sodium ion sensing device applying an extended-gate field effect transistor. As the measurement specification of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention, wherein FIG. 4 shows the electrode specification and the architecture of potassium/sodium ion selective electrode is: depositing a SnO2 film (43) on a glass substrate (40), fixing a conducting wire (42) on the SnO2 film (43), depositing a SnO2 film (43) on a ITO film (41), sealing with epoxy resin (44), fixed a window (4 mm2) by a potassium/sodium ion selective membrane (45), and thus obtaining an architecture of a potassium/sodium ion sensing device applying an extended-gate field effect transistor; and the measurement architecture is, as shown in FIG. 5, a single LT1167 instrumental amplifier (51) as readout circuit that a negative input connects to a reference electrode (53), a positive input connects to a potassium/sodium ion selective electrode (52), both placed into a buffer solution for measurement. If using Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, to prepare 5 bottles of KCL, each has concentration pK1, pK2, pK3, pK4, pK5, and then 0.01 M NaCl adding to each bottle, measuring a detected limit, the detected limit divided by 0.01 to get a sodium ion interference constant (KKPK,Napot) of a potassium/sodium ion sensing device applying a extended-gate field effect transistor according to the present invention. The KK,Napot of this example is 1.132. If using Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as the buffer solution, to prepare 5 bottles of NaCl, each has concentration pNa0.1, pNa1, pNa2, pNa3, pNa4, as measurement architecture to perform measurements, to obtain the measured result as shown in FIG. 7; If using Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, to prepare 5 bottles of NaCl, each has concentration pNa0.1, pNa1, pNa2, pNa3, pNa4, and then 0.01M KCl adding to each bottle, measuring a detected limit, the detected limit divided by 0.05 to get a potassium ion interference constant (KNPNa,Kpot) of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention. The KNNa,Kpot of this example is 10−2.38. As a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention used for mutually correcting the measurement of potassium/sodium ion selective electrodes, FIG. 4 shows the electrode specification, the architecture of a potassium/sodium ion selective electrode is: depositing a ITO film (41) on a glass substrate (40), fixing a conducting wire (42) on the ITO film (41), depositing a SnO2 film (43) on the ITO film (41), sealing with epoxy resin (44), fixing a window (4 mm2) by a potassium/sodium ion selective membrane (45), and thus obtaining an architecture of a potassium/sodium ion sensing device applying an extended-gate field effect transistor; and the measurement architecture is, as shown in FIG. 5, a single LT1167 signal amplifier (51) as a readout circuit, a negative input connects to a reference electrode (53), positive input connects to a potassium/sodium ion selective electrode (52), both placed into a buffer solution for measurement. If using Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, to prepare 5 bottles of KCL, each has concentration pK1, pK2, pK3, pK4, pK5, all measured by the potassium ion selective electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention to obtain a correction plot as shown in FIG. 10. If using Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as a buffer solution, to prepare 5 bottles of NaCl, each has concentration pNa0.1, pNa1, pNa2, pNa3, pNa4, all measured by the sodium ion selective electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention to obtain a correction plot as shown in FIG. 11. If using Tri-HCl, Tris(hydroxymethyl)aminomethane-HCl, concentration 0.05M, as the buffer solution, to prepare NaCl 1M and KCl 0.05M in a bottle, measured by the potassium ion selective electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention to obtain an output potential plot as shown in FIG. 12, and measured by the sodium ion selective electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention to obtain a output potential plot as shown in FIG. 13. The equation 10E-constant/m=aK−KK,Napot aNa can be satisfied by the correction plot of potassium ion selective electrode as shown in FIG. 10 and the output potential of potassium concentration. The equation 10E-constant/m=aNa−KNa,Kpot aK can be satisfied by the correction plot of sodium ion selective electrode as shown in FIG. 11 and the output potential of sodium concentration. The corrected potassium and sodium ion concentration can be jointly determined by the above-mentioned equations 10E-constant/m=aK−KK,NapotaNa and 10E-cnstant/m=aNa−KNa,KpotaK, as shown in table 1. TABLE 1 Results of corrected potassium/sodium ion vs results of uncorrected Uncorrected Actual value result Corrected result Sodium ion pNa 1 pNa = 1.018 pNa = 1.018 Potassisum ion pK 1.3 pK = 0.7816 pK = 1.248 The above table 1 shows the comparison of corrected result and uncorrected result of potassium/sodium ions which using sodium ion selective electrode to correct potassium ion selective electrode, the error rate of potassium ion selective electrode before correction is 39.8%, the error rate of potassium ion selective electrode after correction is 4%, therefore this table illustrates the way of the potassium and sodium ion selective electrodes correcting each other can be used to obtain a result that more close to the actual value. Referring to FIG. 4, shows the cross section view of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention after immobilizing an ion selective membrane to a SnO2/lTO/glass sensing architecture. As seen from the drawing, it is easy and capable of meeting CMOS standard process to fabricate an extended-gate ion sensitive field effect transistor (EGFET); the ion selective membrane is: using the hydro-aliphatic urethane diacrylate (EB2001) as substrate, photocurable, easily microminaturization that facilitate fabricating multiple ion sensors, such a structure do not need a redox layer of polymer to stabilize the response signal, just use the good transparency of a simple hydrophile polymer to read signals steadily, and thus an ion sensing electrode with a simple process can be achieved. Referring to FIG. 5, shows the measurement architecture diagram of a potassium/sodium ion sensing electrode of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention; As illustrated in the drawing, the present invention do not need to add a wave filter circuit, and the measurement results in FIG. 6 and FIG. 7 can be obtained. FIG. 8 shows a measured signal diagram of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention during the concentration range of the potassium ion is between pK1-pK5 after a potassium ionophore intermixed with the hydro-aliphatic urethane diacrylate (EB2001) 33 mg; As seen from the drawing, the hydro-aliphatic urethane diacrylate (EB2001) as substrate encapsulating a potassium ionophore (valinomycin) and a electronegative potassium ion complex (Potassium terakis(p-chlorophenyl)borate), immobilized on a SnO2 film, the potassium ion solution concentration is measured; when the ratio of the potassium ionophore to the hydro-aliphatic urethane diacrylate (EB2001) is 6:33 (w/w) and the potassium ion concentration range is 0.1˜10-4M, the selective potential is about 55.06 mV. FIG. 9 shows a measured signal diagram of a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the present invention during the concentration range of the sodium ion is pNa0-pNa4 after sodium ionophore intermixed with a hydro-aliphatic urethane diacrylate (EB2001) 33 mg. As seen in the drawing, the hydro-aliphatic urethane diacrylate (EB2001) as substrate encapsulating sodium ionophore {Bis[(12-crown-4)methyl]-dodecylmethyl malonate} and a electronegative sodium ion complex (Sodium tetrakis(4-fluorophenyl)borate dehydrate), immobilized on a SnO2 film, the sodium ion solution concentration is measured; when the ratio of sodium ionophore to the hydro-aliphatic urethane diacrylate (EB2001) is 4:33 (w/w) and the potassium ion concentration range is 0.1˜10-4M, the selective potential is about 53.14 mV. Many changes and modifications in the above described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a potassium/sodium ion sensing device applying an extended-gate field effect transistor, particularly to a potassium/sodium ion sensing device applying an extended-gate field effect transistor which uses an ion interference for mutual correction to obtain more accurate values. Therefore, the present invention can be applied to industries such as medical examinations, biomedical materials, and semiconductor device fabrications, etc. 2. Description of the Prior Art As compared with conventional ion selective glass electrodes, at present the solid-state electrode has more advantages, such as low cost, easy miniaturization and durability, non-breakable, etc., therefore the market share is tend to ripe semiconductor integration of field effect transistor substitute for conventional glass electrode. [P. Bergveld, “Development of an ion-sensitive solid-state device for neurophysiological measurements”, IEEE Transactions on Biomedical Engineering, BME-17, pp. 70-71, 1970]. The fluid of a human body can be classified to extra-cellular and intra-cellular fluids, wherein primary ions include sodium, potassium, calcium, etc.; the balance of sodium ion and potassium ion is important particularly. In the normal condition of a human body, the concentration of sodium/potassium ions is stable, the normal value of serum potassium is 3.5-5.0 mM (avg. 4.3 mM), the normal value of serum sodium is 135-145 mM (avg. 140 mM) [pp. 847-900, Sec. 2 Examination, The Clinical Internal Medicine, BOR-SHEN HSIEH, published by Golden Name Press, 1990.] Thus, sodium is a major cation in the extra-cellular fluid of a human body, 98% ion is sodium ion in all extracellular, and 2% ion is sodium ion in all intra-cellular. The potassium and sodium ion concentration will change if a patient has kidney failure or dehydration, thus the doctor can use the unbalance condition of sodium/potassium ions to examine the disease of the human body. The determination of content of sodium/potassium ions in the human body is generally performed by polarographic method, atomic absorption spectrometry (AAS), and the like which need pre-processing and operating inconveniently. Those current commercial pH/sodium/potassium ion electrodes often have errors when used to measure the environment of interfering ion more than the measured ion (that is, the extra-cellular and intra-cellular fluids in the human body). Thus, in order to remove the interference from various ions on electrodes, it is required to measure the ions having greater effects in the solution simultaneously. Patents related to the conventional technology are described as follows: (1) Inventor: D. C. Chan Andy, Patent Number: U.S. Pat. No. 6,416,646; Date of patent: Jul. 9, 2002, Title: “Method of making a material for establishing solid state contact for ion selective electrodes”. This cited reference discloses a polymeric material, a methacrylamidopropyltrimethyl-ammoniumchloride (MAPTAC) or methyllmethacrylate (MMA), applied on the gate of a field effect transistor to fabricate an ion selective electrode, which is stable and reproducible, and polymeric membrane mixable with ion selective material being incorporated in a solid-state electrode; The electric charge of the polymer described in the cited reference is 2.72 mEq/g (millaequivalents/gram), and the polymeric material recited in the claims includes immobilized sites of charge opposite that of mobile ions involved in the redox couple. (2) Inventor: Martijn Marcus Gabriel Antonisse, David Nicolaas Reinhoudt, Bianca Henriette Maria Snellink-Ruel, Peter Timmerman, Patent Nubmer: U.S. Pat. No. 6,468,406. Date of patent. Oct. 22, 2002, Title: “Anion-complexing compound, method of preparing the same, an ion-selective membrane and a sensor provided with such a compound or membrane”. This cited reference discloses the synthesis and application of an ion selective material of alkali and alkaline earth group, using organic synthesis, to prepare compounds with specific functional group; such as —NHC(X)—, —C(X)NH—, —NHC(X)NH—, wherein X includes sulfur or oxygen atom, with its specific compound structure, to achieve the effect for selecting an ion selective material of alkali and alkaline earth group; the cited reference also discloses, adding on a polymer to encapsulate an ion selective material, to prepare an extended gate ion selective electrode. (3) Inventor: Massimo Battilotti, Giuseppina Mazzamurro, Matteo Giongo, Invent Number: U.S. Pat. No. 5,130,265. Date of patent. Dec. 21, 1989, Title: “Process for obtaining a multifunctional, ion-selective-membrane sensor using a siloxanic prepolymer”. This cited reference discloses a process, using a photocurable polymer, to achieve fixing various ion selective materials on a microelement. A claimed process of a sensing device, which using a solvent with a photoinitiator to solve silica and an ion selective material, applied to a substrate in liquid using spinning, and then exposed with appropriate ultraviolet light, after cleaned by an organic solvent, hardening the polymer by heating, and repeating the above, to obtain a sensing electrode in the same substrate, and thus making various ion field effect transistor sensing devices. (4) Inventor: Akihiko Mochizuki, Hideyo lida, Patent Nubmer: U.S. Pat. No. 4,921,591. Date of patent. May 1, 1990, Title: “Ion sensors and their divided parts”. This cited reference discloses an ion selective membrane, includes a vinyl polymer based compound containing a hydroxyl and/or carboxyl group, fixed on an extended gate sensitive field effect transistor. In the claims, it also discloses a reference electrode arranged in the opposite side of a ion selective electrode. The ion selective electrode and reference electrode are separate. The materials of reference electrode is different with the extended gate. (5) Inventor: Noboru Oyama, Takeshi Shimomura, Shuichiro Yamaguchi, Patent Number: U.S. Pat. No. 4,816,118. Date of patent. Mar. 28, 1989, Title: “Ion-sensitive FET sensor”. This cited reference discloses an ion selective electrode (ISFET), the gate of MOSFET is pulled out, and an ion selective membrane is added; wherein a redox layer having a redox function is provided between the isolating membrane and the ion-sensitive layer to improve operating stability and speed of response; an electrically conductive layer or a combination of a metal film and an electrically conductive layer is provided between the isolating membrane and the redox layer to further improve operating stability, the adhesion of the layers and the durability of the sensor. Also disclosed are optimum materials for use as an ion carrier employed in the ion-sensitive layer. (6) Inventor: D. N. Reinhoudt, M. L. M. Pennings, A. G. Talma, Paten Number: U.S. Pat. No. 4,735,702. Date of patent. Apr. 5, 1988, Title: “Method of producing an ISFET and same ISFET”. This cited reference discloses: a method of modifying an oxide surface of a semi-conductor material, incorporated for example in an ISFET, in which a polymer coating is applied to the oxide surface. This cited reference also describes: using a modified polymer to fix oxide functional group to the gate of a field effect transistor or to introduce a metal complex into a polymer, and thus to achieve a product for mass production. Furthermore, since the miniaturization of an optical ion sensor is difficult, although electrical ion sensor can use an integrated circuit process to achieve miniaturization, the sensitive potential signal is subjected to the ion movement in the solution to produce noise. In order to stabilize the potential signal or improve potential interference, generally can add a filter circuit at the back end circuit, or as the above-cited reference (1)-(6), can change the feature of polymer of the ion selective membrane. And, according to the literatures: [IUPAC, “Recommendations for nomenclature of ion-selective electrodes”, Pure and Applied Chemistry, Vol. 66, pp. 2527-2536, 1994. R. Eugster, P. M. Gehrig, W. E. Morf, U. E. Spichiger, and W. Simon, “Selectivity-modifying influence of anionic sites in neutral carrier-based membrane electrodes”, Analytical Chemistry, Vol. 63, pp. 2285-2289, 1991.M. Yanming and E. Bakker, “Determination of complex formation constants of lipophilic neutral ionophores in solvent polymeric membranes with Segmented sandwich membranes”, Analytical Chemistry, Vol. 71, pp. 5279-5287, 1999. S. Amemiya, P. Bulhlmann, E. Pretsch, B. Rusterholz, Y. Umezawa, “Cationic or anionic Sites-selectivity optimization of ion-selective electrodes based on charged ionophores”, Analytical Chemistry, Vol. 72, pp. 1618-1631, 2000.E. Bakker, E. Pretsch, “Ion-selective electrodes based on two competitive ionophores for determining effective stability constants of ion-carrier complexes in solvent polymeric membranes”, Analytical Chemistry, Vol. 70, pp. 395-302, 1998. F. Deyhimi, “A method for the determination of potentiometric selectivity coefficients of ion selective electrodes in the presence of several interfering ions”, Talanta, Vol. 50 (5), pp. 1129-1134, 1999. E. Bakker, “Origin of anion response of solvent polymeric membrane based silver ion-selective electrodes”, Sensors and Actuators B, Vol. 35 (1-3), pp. 20-25, 1996. P. Kane, D. Diamond, “Determination of ion-selective electrode characteristics by non-linear curve fitting”, Talanta, Vol. 44, pp. 1847-1858, 1997], ion interference is: when the solution to be tested contains other ion not to be tested, the amount of the ion not to be tested can affect the output potential, so the output potential can not indicate correct concentration of the ion to be tested. However, using polymer for fixing is a special subject, different polymers will affect the ion diffusivity and ionophore encapsulatement [C. P. Hauser, W. L. D. Chiang, A. W. Graham, “A potassium ion selective electrode with valinomycin based poly (vinyl chloride) membrane and a poly (vinyl ferrocene) solid contact”, Analytical Chimica Acta., Vol. 302, pp. 241-248, 1995. B. Andrey, A. Nataliya, M. Javier, D. Carlos, “Optimization of photocurable polyurethane membrane composition for ammonium ion sensor”, Journal of Electrochemical Soc., Vol. 144 (2), pp. 617-621, 1997. Y. H. Lee, A. H. Hall Elizabeth, “Methacrylate-acrylate based polymers of low plasticiser cont for potassium ion-selective membranes” Analytical Chemica Acta., Vol. 324, pp. 47-56, 1996. B. Jundrey, A. Nataliya, M. Javier, D. Carlos, A. Salvador, B. Jordi “Photocureable polymer matrices for potassium-sensitive ion selective electrode membranes” Analytical Chemistry, Vol. 67, pp. 3589-3595, 1995. Yook-Heng Lee, A. H. Elizabeth, “Assessing a photocured self-plasticised acrylic membrane recipe for Na and K ion selective electrodes”, Analytica Chimica Acta, Vol. 443, pp. 25-40, 2001. K. J. Shinichi, M. S. Arakawa, S. Michiko, O. Tetsuya, S. lkuo, “Flow injection analysis of potassium using an all-solid-state potassium selective electrode as a detector”, Talanta, Vol. 46, pp. 1293-1297, 1998. P. C. Pandey, R. Prakash, “Polyiudole modified potassium ion sensor using dibenzo-18-crown-6 mediated PVC matrix membrane”, Sensors and Actuators B, Vol. 46, pp. 61-65, 1998. M. J. Roger, P. J. S. Barbeiva, A. F. B. Sene, N. R. Stradiotto, “Potentiometria determination of potassium cations using a nickel(II)hexacyanofereate-modified electrode”, Talanta, Vol. 49, pp. 271-275, 1999]. The amount of negative charge ionophore and additive influence the potentiometric selectivity coefficient in potassium/sodium ion electrodes [R. Eugster, P. M. Gehrig, W. E. Morf, U. E. Spichiger, and W. Simon, “Selectivity-modifying influence of anionic sites in neutral carrier-based membrane electrodes”, Analytical Chemistry, Vol. 63, pp. 2285-2289, 1991. S. Amemiya, P. Bulhlmann, E. Pretsch, B. Rusterholz, Y. Umezawa, “Cationic or anionic Sites-selectivity optimization of ion-selective electrodes based on charged ionophores”, Analytical Chemistry, Vol. 72, pp. 1618-1631, 2000], in a potassium/sodium ion sensor, if the ionosphere or electronegative additive is larger than a certain amount, the positive charge of other ions to be tested will be affected by electronegativity. Addressing to the problem of potential interference, the International Union of Pure and Applied Chemistry (IUPAC) had recommended the potential interference parameters of a potentiometric sensor [IUPAC, “Recommendations for nomenclature of ion-selective electrodes”, Pure & Applied Chemistry, Vol. 66, pp. 2527-2536, 1994], potantiometric selectivity coefficient can input The Nikolsky-Eisenman equation to obtain more accurate potassium/sodium ion concentration in practice. Accordingly, it can be seen that the above-described conventional technique still has many drawbacks, are not designed well, and thus need to be improved. In view of disadvantages derived from the above-described conventional techniques, the present inventor had devoted to improve and innovate, and, after studying intensively for many years, developed successfully a potassium/sodium ion sensing device applying an extended-gate field effect transistor according to the invention. | <SOH> SUMMARY OF THE INVENTION <EOH>The object of the invention is to provide a potassium/sodium ion sensing device applying an extended-gate field effect transistor that uses the hydro-aliphatic urethane diacrylate (EB2001) as immobile material capable of simplifying a process for fabricating an ion selective membrane to obtain a single layer membrane potassium/sodium ion sensor without an add-on wave filter circuit. A further object of the present invention is to provide a potassium/sodium ion sensing device applying an extended-gate field effect transistor that uses a process which comprising: use realized tin oxide (SnO 2 ) as substrate and then is adhered with potassium/sodium ion selective membrane, measure the concentration potential of each ion, input known potentiometric sensitivity coefficient to the Nikolsky-Eisenman equation to reduce interference, and obtain the actual value. Another object of the present invention is to provide a potassium/sodium ion sensing device applying an extended-gate field effect transistor with a fabrication method possessing advantages such as simple equipment, low cost, mass production, etc., thus the potassium ion and sodium ion sensing device according to the present invention has high feasibility and high applicability. The potassium/sodium ion sensing device applying an extended-gate field effect transistor capable of achieving the above-mentioned objects, based on an extended-gate ion sensitive field effect transistor, using the extended gate of the extended-gate ion sensitive field effect transistor as a signal intercept electrode, and immobilizing the hydro-aliphatic urethane diacrylate (EB2001) intermixed with electronegative additive, ionophores such as potassium, sodium, etc., to fabricate a potassium/sodium ion sensing electrode. The present invention utilizes the photocurability and good hydrophilicity of the hydro-aliphatic urethane diacrylate (EB2001), and fixes potassium/sodium ionophore, can obtain a non-wave filter, single-layer, stable signal potassium and sodium ion sensor. Thus, when the present invention is applied to measure the concentration of potassium/sodium ions in a sample solution, the mutual interference between potassium/sodium ion electrodes can be reduced, so the measured value can be more close to the actual value. These features and advantages of the present invention will be fully understood and appreciated from the following detailed description of the accompanying Drawings. | 20040715 | 20070116 | 20060119 | 63418.0 | H01L2980 | 0 | PIZARRO CRESPO, MARCOS D | METHOD FOR FORMING POTASSIUM/SODIUM ION SENSING DEVICE APPLYING EXTENDED-GATE FIELD EFFECT TRANSISTOR | SMALL | 0 | ACCEPTED | H01L | 2,004 |
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10,891,579 | ACCEPTED | Content recordation techniques | Content recordation techniques are described. In an implementation, a method includes querying electronic program guide (EPG) data to determine if a content item described in a recording document is available for recording. If the content item is available, a reference is added to a recording list for causing recordation of the content item. | 1. A method comprising: querying electronic program guide (EPG) data to determine if a content item described in a recording document is available for recording; and if the content item is available, adding a reference in a recording list for causing recordation of the content item. 2. A method as described in claim 1, wherein the querying is performed by execution of a parser module on a head end. 3. A method as described in claim 1, wherein: the querying is performed by execution of a parser module on a head end; and the reference in the recording list is for causing recordation of the content item by a client. 4. A method as described in claim 1, wherein the querying is performed by execution of a parser module on a client. 5. A method as described in claim 1, wherein: the query is performed at a client; and the reference in the recording list is for causing recordation of the content item at a head end. 6. A method as described in claim 1, further comprising determining if the available content item conflicts with another content item in the recording list. 7. A method as described in claim 1, further comprising examining client state data that describes conditional access rights of a plurality of clients to determine if recordation of the content item for a particular said client is permitted. 8. A method as described in claim 1, wherein the recording document describes the content item through at least one of a restrictive criterion, a service, a time, or a genre. 9. A method as described in claim 1, further comprising generating the recording document from a textual description of the content item. 10. A method as described in claim 9, wherein the textual description is selected from the group consisting of: one or more words entered by a user via a user interface; an article; a text message; an email; and another content item. 11. One or more computer readable media comprising computer executable instructions that, when executed by a computer, direct the computer to perform the method as described in claim 1. 12. A method comprising: examining a textual description to locate one or more words that describe a content item; comparing the one or more words with electronic program guide (EPG) data to determine if the content item is available for recording; and if the content item is available, adding a reference in a recording list to cause recordation of the content item. 13. A method as described in claim 12, wherein the textual description is selected from the group consisting of: one or more words entered by a user via a user interface; an article; a text message; an email; and another content item. 14. A method as described in claim 12, wherein the content item is selected from the group consisting of: a television program; a movie; a picture; a music file; and media. 15. A method as described in claim 12, wherein: the examining is performed by executing a recording module on a client; and the comparing and the adding are performed by executing a parser module on a head end. 16. A method as described in claim 12, wherein the examining, the comparing, and the adding are performed by executing a recording module and a parser module on a client. 17. A method as described in claim 12, further comprising generating a recording document that includes the located one or more words. 18. A method as described in claim 12, further comprising: generating a recording document that includes the located one or more words; communicating the recording document to a head end which executes a parser module to perform the comparing and the adding; and communicating the recording list to a client to cause recordation of the content item described in the EPG data through execution of a navigation module on the client. 19. A method as described in claim 12, further comprising determining if the client is authorized to record the content item. 20. A method as described in claim 19, wherein the determining is performed at a head end using client state data that is stored on the head end. 21. One or more computer readable media comprising computer executable instructions that, when executed by a computer, direct the computer to perform the method as described in claim 12. 22. One or more computer readable media comprising computer executable instructions that, when executed by a computer, direct the computer to: examine a textual description to locate one or more words that describe a content item; generate a recording document having the one or more words; and form a communication for communicating the recording document for comparison with electronic program guide (EPG) data to determine if the content item described by the recording document is available for recording. 23. One or more computer readable media as described in claim 22, wherein the computer executable instructions further direct the computer to: determine if the content item described by the recording document is available for recording; and if the content item is available, add a reference to the available content item to a recording list. 24. One or more computer readable media as described in claim 22, wherein the computer executable instructions further direct the computer to examine client state data that describes conditional access rights of a plurality of clients to determine if recordation of the content item for a particular said client is permitted. 25. One or more computer readable media as described in claim 22, wherein the computer executable instructions further direct the computer to determine if the available content item conflicts with another content item in a recording list. 26. One or more computer readable media as described in claim 22, wherein the textual description is selected from the group consisting of: one or more words entered by a user via a user interface; an article; a text message; an email; and another content item. 27. A head end comprising: a processor; and memory configured to maintain: electronic program guide (EPG) data; a recording document having a plurality of elements which describe a content item; and a parser module that is executable on the processor to: determine if the content item described in the recording document is available for recording by comparing at least one said element with the electronic program guide (EPG) data; and if the content item is available, add a reference to a recording list for causing recordation of the content item. 28. A head end as described in claim 27, wherein the reference in the recording list is for causing recordation of the content item in the memory. 29. A head end as described in claim 27, wherein the reference in the recording list is for causing recordation of the content item at a client. 30. A head end as described in claim 27, wherein the parser module is further executable on the processor to generate the recording document from a textual description of the content item. 31. A head end as described in claim 30, wherein the textual description is selected from the group consisting of: one or more words entered by a user via a user interface; an article; a text message; an email; and another content item. 32. A head end as described in claim 27, wherein the parser module is further executable on the processor to examine client state data that describes conditional access rights of a plurality of clients to determine if recordation of the content item for a particular said client is permitted. 33. A head end as described in claim 27, wherein the parser module is further executable on the processor to determine if the available content item conflicts with another content item referenced in the recording list. 34. A client comprising: a processor; and memory configured to maintain: an electronic program guide (EPG) formed from a plurality of EPG data; a recording document having a plurality of elements which describe a content item; and a parser module that is executable on the processor to: determine if the content item described in the recording document is available for recording by comparing at least one said element with the electronic program guide (EPG) data; and if the content item is available, add a reference in a recording list, based on the query, for causing recordation of the content item. 35. A client as described in claim 34, wherein the reference in the recording list is for causing recordation of the content item at a head end. 36. A client as described in claim 34, wherein the reference in the recording list is for causing recordation of the content item through execution of a navigation module on the client. 37. A client as described in claim 34, wherein the parser module is further executable on the processor to generate the recording document from a textual description of the content item. 38. A head end as described in claim 37, wherein the textual description is selected from the group consisting of: one or more words entered by a user via a user interface; an article; a text message; an email; and another content item. 39. A client as described in claim 34, wherein the parser module is further executable on the processor to examine client state data, which describes conditional access rights, to determine if recordation of the content item is permitted. 40. A client as described in claim 34, wherein the parser module is further executable on the processor to determine if the available content item conflicts with another content item in the recording list. 41. A system comprising: a network; a head end that is communicatively coupled to the network, includes a database having electronic program guide (EPG) data, and has a parser module that is executable thereon to: query the EPG data to determine if a content item described in a recording document received from over the network is available for recording; if the content item is available, examine client state data that describes conditional access rights of a plurality of clients to determine if recordation of the content item for a particular said client is permitted; if recordation of the content item for the particular said client is permitted, add a reference in a recording list for causing recordation of the content item; and form a communication for communicating the recording list via the network; and the particular said client that is communicatively coupled to the network and includes a navigation module that is executable thereon to: receive the communication having the recording list; and record the referenced content item. | TECHNICAL FIELD The present invention generally relates to the field of content and in particular to content recordation techniques. BACKGROUND Users are continually exposed to an ever increasing variety of clients that provide network access, such a set-top boxes, wireless phones, computers, and so on. A user of a set-top box, for instance, may view traditional television programming obtained from a broadcast network for display on a television, as well as order pay-per-view movies, receive video-on-demand (VOD), play “live” video games, and so on. Likewise, a user of a wireless phone may place and receive traditional telephone calls, as well as read email, download digital music, and so on. Another such example is a digital video recorder (DVR). A DVR typically includes non-volatile storage (e.g., a hard disk) that enables the user to record desired content. DVR's also offer control functionality, such as the ability to pause content that is currently being broadcast and allows viewers to watch the content, while still in progress, from the point it was paused. The DVR plays back the content from storage, starting at the pause event, while continuing to record the currently-broadcast content. Additionally, the DVR may support other control functions, such as rewinding, fast forwarding a stored program, slow motion playback, and the like. To record content using a DVR, a user was typically required to directly interact with the DVR itself. In some instances, the user could configure the DVR to record related content by specifying parameters to be matched with those of available content to locate potentially desirable content. For example, the user could specify the title of a television program so that the DVR would record each television program having that title. However, the user was not assured that the DVR would record a particular content item of interest. In other words, the user could not be certain that the potentially desirable content recorded by the DVR corresponded with the actual content the user wished to record. For example, although the DVR may be configured to record a particular television program, the DVR might fail to record a special regarding the actors in that particular television program. Therefore, when the user was located “away” from the DVR, the user could not cause the DVR to record the particular content item, even if the user had access to one or more of the clients that provide network access as previously described. Accordingly, there is a continuing need for improved content recordation techniques. SUMMARY Content recordation techniques are described. The content recordation techniques may be utilized when the user is local to and remote from the client. For example, a user, when remotely located from a client configured as a digital video recorder (DVR), interacts with a remote device that is configured as a wireless phone. The user utilizes the wireless phone to access a review of a television program via the Internet. Based on the review, the user invokes a recording document that is embedded in the review to be communicated to the remote client. The recording document describes the television program, such as by describing a title, actors, broadcast time, service (e.g., channel) that broadcasts the television program, and so on. Upon receipt of the recording document, the remote client executes a parser module to examine the recording document to determine if the television program described in the recording document is available for being recorded by the remote client. For instance, the recording document may be compared with electronic program guide (EPG) data that is received from a head end, EPG data service, and so on. The EPG data may be utilized to determine if the television program is available. The EPG data may also be utilized to determine how the television program is to be recorded, such as by supplying a channel and broadcast start time. If the television program is available, a reference to the television program is added to a recording list based on the EPG data. For example, the broadcast channel and the broadcast start time may be added to the recording list. The recording list is then utilized by the remote client to cause the client to record the content. In another instance, the recording document may cause the head end to cause the client to record the content, such as by examining EPG data stored at the head end to determine if the content is available for recording. If so, the head end causes the client the record the content. In a further instance, the recording document may cause the head end itself to record the content, such as in a network digital video recorder (NDVR) scenario. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an illustration of an environment in an exemplary implementation that includes a content provider that is communicatively coupled to a client over a network. FIG. 2A is an illustration of an exemplary implementation showing a distribution server, the client, a head end, and a remote device of FIG. 1 in greater detail such that the head end is configured to record content. FIG. 2B is an illustration of another exemplary implementation showing a distribution server, the client, a head end, and a remote device of FIG. 1 in greater detail such that the client is configured to record content. FIG. 3 is an illustration of a system showing a variety of content recordation techniques as implemented by the distribution server and the client of FIG. 2A. FIG. 4 is a flow diagram depicting a procedure in an exemplary implementation in which a recording document is utilized to record a particular content item. FIG. 5 is an illustration of a system in an exemplary implementation in which a graphical user interface (GUI) is provided by a recording module to dynamically generate a recording document based on user input. FIG. 6 is an illustration of a system in an exemplary implementation in which the recording module is executed to examine a textual description of content to dynamically generate a recording document. FIG. 7 is a flow diagram depicting a procedure in an exemplary implementation in which a client dynamically generates a recording document that is utilized to determine availability of a particular content item for recording by the client. The same reference numbers are utilized in instances in the discussion to reference like structures and components. DETAILED DESCRIPTION Overview Content recordation techniques are described. In an implementation, a content recordation technique is described in which a client, such as a digital video recorder (DVR), is configured to record content streamed from a head end through use of a recording document that describes the content. The recording document may be provided in a variety of ways, such as embedded in a web site, shared via email or text messaging, submitted via an application programming interface (API), manually written by a user, and so on. The recording document is processed via a parser module to locate the content item that is described by the recording document. In one scenario, the parser module compares the recording document with an electronic program guide (EPG) that is stored on the client to find a matching content item that is described in the EPG data. If a sufficient match is found, a reference to the matching content item is added to a recording list based on the EPG data, such as a broadcast channel and time to record the matching content item. In another scenario, the head end processes the recording document provided by a remote device to determine whether the described content item is available. If so, the head end then causes the client to record the particular content item, such as through communication of a recording list to the client. Thus, a user may cause a particular content item to be recorded without direct interaction with the client. In a further implementation, the head end stores client state data to process content recordation requests. For example, the head end may include client state data, such as ratings limits, favorite channels, levels of service, and so on, that is accessible locally by the head end. The head end may utilize this client state data to determine if the client is permitted to access the content item described by the recording document. If so, the head end may then cause the client to record the content. By performing the determination utilizing client state data at the head end, the head end provides an authoritative source for processing requests to record content by the client. This may result in a variety of increased functionality that is available to the user, such as an ability to change from an old client to a new client without manually updating client state data from the old client to the new client, remote initiation of content recordation without obtaining a connection with the client itself, and so on. Exemplary Environment FIG. 1 is an illustration of an environment 100 in an exemplary implementation showing a content provider 102 that is communicatively coupled to a client 104 over a network 106. The network 106 in the following implementations is an example of a wide area network (WAN), such as the Internet, and may also include a variety of other networks, such as a broadcast network, an intranet, a wired or wireless network, and so forth. The client 104 is configured to receive content communicated from the content provider 102 over the network 106. The content provider 102 includes content 108(k), where “k” can be any integer from 1 to “K”, that is locally stored on the content provider 102. The content 108(k) may include a variety of data, such as television programming, video-on-demand, one or more results of remote application processing, and so on. The content provider 102 communicates the content 108(k) over a network 110 to a head end 112. The network 110 may be the same as or different from network 106. For example, the network 110 may represent a dedicated network connection between the content provider 102 and the head end 112 while network 106 is implemented by the Internet, both networks 106, 110 may be the Internet, and so on. The content 108(k) may then be stored in a database 114 as content 116(n), where “n” can be any integer from 1 to “N”, on the head end 112 for communication over the network 106 to the client 104. In other words, the content 116(n) stored in the database 114 may be copies of the content 108(k) received from the content provider 102 over the network 110. The head end 112, as illustrated, includes a distribution server 118 to format and distribute the content 116(n) over the network 106. Distribution from the head end 112 to the client 104 may be accomplished in a number of ways, including cable, RF, microwave, and satellite. Although the head end 112 is illustrated as separate from the content provider 102, the content provider 102 may also include the head end 112. The head end 112 may also include a database 120 having a plurality of EPG data 122(m), where “m” can be any integer from one to “M”. The EPG data 122(m) is used to construct an EPG 124 for display by the client 104 to a user. The EPG 124, for instance, may enable the user to observe a listing of television programs that are currently being broadcast from the head end 112, as well as a listing of television programs that will be broadcast in the future. Additionally, the EPG 124 may allow the viewer to navigate to a television program (e.g., content 116(n)) from the EPG 124 itself. To provide additional information to the user, the EPG 124 may include one or more content characteristics that describe content represented in the EPG 124. The content characteristics may include title, broadcast time, broadcast channel, output duration of the content, plot description, a rating (e.g., G, PG, PG-13, R, etc.), a principle actor's name, and so on. The EPG data may be communicated to the client 104 in a variety of ways. In one instance, the EPG data 122(m) is broadcast to the client 104 utilizing a carousel file system. The carousel file system repeatedly broadcasts the EPG data over an out-of-band (OOB) channel to the client 104 over the network 106. Although the head end 112 is illustrated as including the EPG data 122(m), in another instance the EPG data 122(m) is provided over the network 106 utilizing a separate EPG data service. The client 104 may be configured as a computer that is capable of communicating over the network 106, such as a desktop computer, a mobile station, an entertainment appliance, a set-top box 126 that is communicatively coupled to a display device 128 as illustrated, and so forth. Although the set-top box 126 is shown separately from the display device 128, the set-top box 126 may be built into the display device 128 to form an integral unit. The client 104 may also relate to a person and/or entity that operate the client 104. In other words, client 104 may describe a logical client that includes a user and/or a machine. Although one client 104 is illustrated, a plurality of clients may be communicatively coupled to the network 106. The client 104 may also include a database 130 having locally stored content 132(j), where “j” can be any integer from 1 to “J”. For example, the client 104 may be configured as a DVR that stores the database 130 in hard disk memory. Due to the size of the memory, users are able to record content, such as content 116(n) streamed from the head end 112. As previously described, the DVR also offers control functions, such as the ability to pause content that is currently being broadcast and allows viewers to watch the content while still in progress from the point it was paused. The DVR plays back the content from disk memory, starting at the pause event, while continuing to record the currently-broadcast content in the disk memory. Additionally, the DVR may support other control functions, such as rewinding, fast forwarding a stored program, slow motion playback, and the like. The client 104 is equipped with sufficient processing and storage capabilities to store and run a navigation module 134. The navigation module 134, when executed on the client 104, provides control functions for interacting with content. For example, the control functions may include the DVR control functions as previously discussed, as well as channel selection, electronic program guide (EPG) navigation, and so on. In another implementation, the navigation module 134 provides media player functionality, such as to play media having audio and/or visual data, such as MP3 data. In a further implementation, the client 104 may execute the navigation module 134 to cause recordation of the content 116(n) at the distribution server 118. For example, the navigation module 134 may form a request that is communicated to the distribution server 118 over the network 106 to record content 108(k) communicated to the distribution server 130 from the content provider 102. The distribution server 118, in response to the request, records the requested content such that the navigation module 134 operates as a network digital video recorder (NDVR). Thus, through execution of the navigation module 134, the client 104 may playback locally-stored content 132(j), content 116(n) that is stored remotely over the network 106, and may even control the recordation and playback of the remotely stored content 116(n) to the client 104. Generally, any of the functions described herein can be implemented using software, firmware (e.g., fixed logic circuitry), manual processing, or a combination of these implementations. The terms “module,” “functionality,” and “logic” as used herein generally represent software, firmware, or a combination of software and firmware. In the case of a software implementation, the module, functionality, or logic represents program code that performs specified tasks when executed on a processor (e.g., CPU or CPUs). The program code can be stored in one or more computer readable memory devices. The content recordation techniques described below are platform-independent, meaning that the content recordation techniques may be implemented on a variety of commercial computing platforms having a variety of processors. The environment 100 supports a variety of techniques for recordation of the content 132(j), 116(n) through use of a recording document 136. The recording document 136, for instance, describes content to be recorded and may conform to an extensible Markup Language (XML) schema that is parsable by a parser module 138 to locate a particular content item. For example, the recording document 136 may describe a title and a start time for a desired content item. The parser module 138 is executed on the distribution server 118 to compare the title and the start time described in the recording document with the EPG data 122(m) stored in the database 120 to determine if and when the particular content item is available. If the particular content item is available, a reference to the particular content item is added to a recording list 140 to cause the particular content item to be recorded. For example, the recording list 140 may be utilized by the distribution server 118 to record content 116(n) at the head end 112 in a NDVR scenario. In another example, the recording list 140 is communicated to the client 104 to cause the navigation module 134 to record content 132(j) locally in a DVR scenario. In a further example, the recording document 136 is communicated from the remote device 142 to the client 104 for parsing by the client 104, an example of which is shown in relation to FIG. 2B. The recording document 136 may be provided in a variety of ways. As illustrated in FIG. 1, the recording document 136 is stored on a remote device 142 that is communicatively coupled to the network 106. Therefore, a user of the remote device 142 may provide the recording document 136 to the head end 112 to cause recording of content described by the recording document 136. Thus, the recording document 136 may be provided remotely by the remote device 142 such that the user does not need to interact with the client 104 locally to cause recordation of desired content. A variety of other ways of providing the recording document 136 are described in relation to FIGS. 2A, 2B, and 3. FIG. 2A is an illustration of an exemplary system 200 showing the distribution server 118, the client 104, and the remote device 142 of FIG. 1 in greater detail. The client 104 includes a processor 202 and memory 204. Processors are not limited by the materials from which they are formed or the processing mechanisms employed therein. For example, processors may be comprised of semiconductor(s) and/or transistors (e.g., electronic integrated circuits (ICs)). In such a context, processor-executable instructions may be electronically-executable instructions. Alternatively, the mechanisms of or for processors, and thus of or for a computing device, may include, but are not limited to, quantum computing, optical computing, mechanical computing (e.g., using nanotechnology), and so forth. Memory 204 may include one or more memory devices, such as read only memory (ROM), random access memory (RAM), hard disk memory, removable media memory devices, and so on. The navigation module 134 and the recording list 140 are illustrated as being executed on the processor 202 and are storable in memory 204. The EPG 124 is illustrated as being stored in the memory 204 and is executable on the processor 202. It should be noted that in the illustrated system 200 of FIG. 2A, the recording list 140 is depicted within the client 104 to show that the recording list 140 may be configured for use by the navigation module 134 to cause recordation of content, further discussion of which may be found starting in relation to FIG. 4. The client 104 may also include a network interface 206 for receiving the content 116(n) of FIG. 1 that is communicated (e.g., streamed) over the network 106. For example, the network interface 206 may be configured as a tuner that receives broadcast content from over the network 106, may be configured as a transmitter/receiver (transceiver) that is suitable for two-way communication over the network 106, and so on. Thus, the network interface 206 may be configured to transmit and receive messages over the network to and from the head end 112 and/or the remote device 142. Content 116(n) received from the network 106 via the network interface 206 may be stored in the database 130 for later output by the client 104 and/or provide for immediate output of the content 116(n). The database 130 is illustrated as being separate from memory 204, but may also be included in memory 204. For example, the storage device for the database 124 may be configured as a hard disk drive and the memory 204 may be configured as RAM, both the memory 204 and the database 130 may be implemented as RAM, both the memory 204 and the database 130 may be implemented as removable memory, and so forth. The client 104 executes the navigation module 134 to retrieve the content 132(j) from the database 124 and output the content 132(j) through an output interface 208 for rendering on the display device 122. Thus, in this implementation, the client 104 is capable of operating as a DVR that stores and plays back the content 1320(j). The client 104 may be locally controlled by a user via inputs provided by an input device 210. The inputs are received by the client 104 from an input interface 212 over a local connection 214. The input interface 212, local connection 214 and input device 210 may be configured in a variety of ways. For example, the input interface 212 may be configured as a wireless port, such as an infrared (IR) or Bluetooth wireless port, for receiving wireless communications from input device 210, such as a remote control device, a handheld input device, or any other wireless device, such as a wireless keyboard. In alternate embodiments, the input interface 212 may use an RF communication link or other mode of transmission to communicate with client 104, such as a wired connection which may include a universal serial bus (USB) connection, and so on. When output of content is requested, the navigation module 134 is executed on the processor 202 to obtain content, such as from content 116(n) of FIG. 1 that is streamed from the distribution server 118 over the network 106, content 132(j) that is stored locally on the database 130, and so on. The navigation module 134 may also restore the content to the original encoded format as provided by the content provider 102 of FIG. 1. For example, content 116(n) of FIG. 1 may be compressed and then streamed from the distribution server 118 to the client 104. Therefore, when the navigation module 134 receives the content, the content may be decompressed for rendering by the display device 128. The distribution server 118 also includes a processor 216 and memory 218. The parser module 138 is illustrated as being executed on the processor 216 and is storable in memory 218. The memory 218 of the distribution server 118 is also illustrated as including a plurality of client state data 220(l), where “l” can be any integer from 1 to “L”. The client state data 220(l) is utilized to process requests to record content, such as at the head end 112 of FIG. 1 as content 116(n) and/or at the client in database 130 as content 132(j). For example, the distribution server 118 may include a content manager module 222 (hereinafter, “manager module”) that is executable on the processor 216 to manage client 104 content access. The client state data 220(l), for instance, may specify parental blocks to prevent viewing of content items, may specify conditional access rights (e.g., digital access rights) of the client for particular items of content, rating limits, favorite channels, level of service provisioned, and so on. The manager module 222, when executed, may determine if the client 104 is permitted (i.e., authorized) to record the particular content item, and if so, the distribution server 118 causes the client 104, and specifically the navigation module 132, to record the particular content item. In this way, the head end 112 provides an authoritative source for client state data 220(l) in the system 200 and environment 100 as shown, respectively, in FIGS. 1 and 2. In an implementation, the distribution server 118 may be considered the primary source for the client state data 220(l) for a particular client, even over the client 104 itself. For example, by storing the client state data 220(l) on the distribution server 118, a user may switch set-top boxes without transferring client state data between the set-top boxes. Further discussion of use of the client state data 220(l) may be found in relation to FIG. 7. The remote device 142 is also illustrated as including a processor 224 and memory 226. The recording document 136 is illustrated as being stored in memory 226 and is executable on the processor 224. The remote device 142 also includes a recording module 228 which is illustrated as being executed on the processor 224 and is storable in memory 226. The recording module 228, when executed, generates the recording document 136 for a particular content item. For example, the recording module 228 may provide a user interface for accepting user inputs that describe a particular content item. The user inputs are processed by the recording module 228 to generate a recording document 136 that follows a schema that is understood by the parser module 138. The parser module 138, when executed, parses the recording document 136 to locate and compare descriptive data in the recording document 136 with EPG data 122(m) in the database 120. EPG data 122(m) that matches the descriptive data is then utilized to determine how to record a particular content item described in the recording document 136. A reference to the particular content item is then added to the recording list 140 to cause the navigation module 134 to be executed on the client 104 to record the particular content item. A variety of other scenarios are also contemplated such that the user may cause recordation of content at the client 104 and/or the head end 112 of FIG. 1, further examples of which may be found in relation to the following figure. FIG. 2B is an illustration of an exemplary system 250 showing the distribution server 118, the client 104, and the remote device 142 of FIG. 1 in greater detail such that the client includes the functionality to parse a recording document. In the system 200 described in relation to FIG. 2A, the distribution server acted as a central repository for client state data 220(L) and executed the parser module 138 to parse the recording document 136. In the exemplary system 250 illustrated in FIG. 2B, however, the client 104 executes the parser module 138 to parse the recording document 136 that is communicated from the remote device 142 over the network 106. The parser module 138 may then be utilized to populate the recording list 140 as previously described by comparing the recording document 136 with EPG 124 that is stored in the memory 204. Thus, in this instance, the head end 112 acts to broadcast content 116(n) over a broadcast network 252 and does not actively participate in the recordation of the content 132(j) on the client 104, further discussion of which may be found in relation to FIG. 6. FIG. 3 is an illustration of a system 300 showing a variety of content recordation techniques as implemented by the distribution server 118 and the client 104 of FIG. 2A. One such content recordation technique is the inclusion of the recording document 302 within content 108(k). For example, the client 104 may receive content 108(k) from the content provider 102 of FIG. 1. The content 108(k) in this example is a television program which includes credits which describe the actors, producers, and so on. The credits may also include a preview for next week's episode of the television program. The preview has an embedded recording document 302 which causes an interactive icon to appear that, when selected, allows the user to automatically schedule a recording for the next episode of the television program. The recording document 302 is then communicated to the distribution server 118 over the network 110 for parsing by the parser module 138. The parser module 138, when executed, locates the particular content item (e.g., the next episode of the television program) based on the recording document 302 and the EPG data 122(m) and adds a reference to the particular content item to a recording list 140. The recording list 140 causes the navigation module 134 to record the content locally in the database 130 as content 132(j). Thus, the recording document 302 embedded in the content 108(k) provides for automatic recording of the next episode of the television program with minimal user intervention. In another such technique, a remote content recordation technique is provided by using a remote record service 304. For example, the remote record service 304 may provide a web site which enables a user to select content for recording. The web site 304 may then communicate a recording document 306 that describes the content selected by the user to cause the client 104 to automatically record the selected content as previously described. In a further such technique, the user interacts with the remote device 142 to remotely record content using the client 104. For example, the remote device 142 may execute an email module 308 that causes an email that contains a recording document 310 to be communicated to the distribution server 118. The distribution server 118 may then execute the parser module 138 to compare the descriptive data in the recording document 310 with the EPG data 122(m) to determine if the particular content item referenced in the email is available. If so, the parser module138 may then be executed to determine if access to the particular content item is permitted by the client 104 based on the client state data 220(l). For example, the client state data 220(l) may indicate whether the user subscribes to a content service package that includes the particular content item. If the user does have conditional access rights, the particular content item is added to the recording list 140 for causing the navigation module 134 to record the particular content item as content 132(j) in the database 130. In another example, the remote device 142 may include a text messaging module 312 to receive a text message from another remote device. The text message may describe a particular content item, such as by providing the title, names of actors, genre, and so on. The text message may be examined to dynamically generate the recording document 310 that contains the content descriptions from the text message. The recording document 310 may then be communicated to the distribution server 118 for processing as previously described. In this example, the recording document 310 is dynamically generated, further discussion of which may be found in relation to FIGS. 5-7. Although the system 300 of FIG. 3 described the execution of the parser module 138 on the distribution server 118, the parser module 138 may also be executed on the client 104. For example, the parser module 138, when executed on the client 104, may compare the descriptive data in the recording document 306 with the EPG 124 (e.g., the EPG data utilized to form the EPG stored on the client 104) to determine availability of the particular content item. Further discussion of execution of the parser module 138 by the client 104 may also be found in relation to FIGS. 5-7. Although a variety of exemplary content recordation techniques have been described, a variety of other content recordation techniques may also be provided that utilize a recording document for comparison with EPG data. Exemplary Procedures The following discussion describes content recordation techniques that may be implemented utilizing the previously described systems and devices. Aspects of each of the procedures may be implemented in hardware, firmware, or software, or a combination thereof. The procedures are shown as a set of blocks that specify operations performed by one or more devices and are not necessarily limited to the orders shown for performing the operations by the respective blocks. FIG. 4 is a flow diagram depicting a procedure 400 in an exemplary implementation in which a recording document is utilized to record a particular content item. At block 402, a recording document 404 is invoked by a remote device 142 for a particular content item. For example, the remote device 142 may access a web site 406 that provides an output of a web page 408 for viewing at the remote device 142. The web page 408, when provided to the remote device 142, may also include the recording document 404 that describes a particular content item. For instance, the web page 408 may include a review of a television show that is available from a broadcast from a head end 112. If the user wishes to record the television show, the user selects a link in the web page 408, which causes the recording document to be invoked. The recording document 404 in this example follows an XML recording schema. The XML recording schema is an abstract representation depicting the interrelationship between attributes and elements of an XML object, which in this instance is the recording document 404 or a portion of the recording document 404. An example of the recording document 404 which complies with an exemplary XML recording schema is shown as follows: <?xml version=“1.0” encoding=“utf-8” ?> <!-- Sample Click-to-Record (NBC Single-Episode Scenario) --> <clickToRecord xmlns=“urn:schemas-microsoft-com:ehome:clicktorecord”> <ds:Signature xmlns:ds=“http://www.w3.org/2000/09/xmldsig#”> <!-- XML Signature goes here --> </ds:Signature> <body> <metadata> <!-- The following information should be considered insecure unless signed. --> <description>A very special episode of Friends.</description> <moreInfoUrl>http://www.nbc.com/friends/</moreInfoUrl> </metadata> <!-- hard prepad and postpad 5 minutes - if airing specified isn't found, suggest another one --> <programRecord prepadding=“5” postpadding=“5” allowAlternateAirings=“true” allowAlternateService=”false”> <program> <key field=“urn:schemas-microsoft-com:ehome:epg:program#title” match=“exact”>Friends</key> <key field=“urn:schemas-microsoft- com:ehome:epg:program#episodetitle” match=“exact”>The One Where Chandler Marries Monica</key> </program> <service> <key field=“urn:schemas-microsoft- com:ehome:epg:service#affiliate” match=“startswith”>NBC</key> </service> <!-- Folks in PST have a time (in UTC) specified --> <airing timeZone=“EST”> <key field=“urn:schemas-microsoft- com:ehome:epg:airing#starttime”>2003-10-15T08:00:00Z</key> </airing> <!-- Other folks record if the show is found within 3 hours of the UTC time specified --> <airing searchSpan=“180”> <key field=“urn:schemas-microsoft- com:ehome:epg:airing#starttime”>2003-10-15T08:00:00Z</key> </siring> </programRecord> </body> </clickToRecord> The outermost element <clickToRecord> is the root element of the recording document 404, which is defined by the namespace “urn:schemas-microsoft-com:ehome:clicktorecord”. The <clickToRecord> element contains an element: <body> plus an optional digital signature conforming to an XML Signature specification. The <body> element contains a single <metadata> element followed by one or more <programRecord> elements. The <metadata> element may encapsulate several sub-elements to providing additional data that describes the requested content item. The following is a list of exemplary <metadata> sub-elements: Element Usage <description> Description of the package (e.g., A Very Special Episode of Friends) <expires> Date/Time after which the recording document expires. <moreInfoUrl> Hyperlink to the source's website (e.g., http://entertainment.msn.com/tv) <updateUrl> Pointer to a URL that may contain updated versions of the recording document to account for schedule changes. One or more record definition elements may be included after the <metadata> element as shown in the above exemplary recording document 404. A <programRecord> record definition element is included which covers both one-time and series recording scenarios. As shown in the sample document above, the <programRecord> element may include several optional attributes, examples of which are described as follows: De- Attribute fault Usage prepadding/ 0/0 Specifies pre-padding and/or post-padding postpadding of the recording in minutes. For example, padding may be utilized to account for a lack of clock synchronization between the head end 112 of FIG. 1 and the client 104. allowAlternateAirings true Specifies how to handle instances in which a specified broadcast of a content item cannot be found. If this attribute is “true”, a search for the same content item is performed for different scheduled times and the user is informed of the change, if any. If this attribute is“false”, and the show is not found within the specified time window, then the request will fail and the user will be informed. allowAlternateServices false Similar to the “allowAlternateAirings”, however, by specifying “true” different content providers (e.g., broadcasters) may be specified. programDuration 0 Specifies an output duration of the content item. This may be used if the content item is not found in the current EPG and a temporary recording event must be created. If 0, the content item must appear in the guide or the query fails. firstRunOnly false Don't record reruns. daysOfWeek 0x7F Indicates which days of the week a content item may be recorded for manual and generic “keyword” requests. isRecurring false This element differentiates between one- time and series request behavior for the content item. The <programRecord> element may include a variety of element types as children that further describe the particular content item, such as <program> (e.g., a title of a television program), <service> (e.g., a broadcast channel that provides the television program), and <airing> (e.g., a time when the television program is to be broadcast). Each of these elements may occur more than once in the recording document 404. At block 410, the remote device communicates the recording document 404 to the head end 112. For example, the recording document 404 may be transmitted (i.e., pushed) over the network 106, implemented using the Internet, for receipt by the head end 112. In another example, the recording document is “pulled” from the remote device 142 by the head end 112. For instance, the head end 112 may be configured to periodically monitor the remote device 142 for presence of the recording document 404. At block 412, the head end 112 queries the database 120 of EPG data 122(m) to determine if the particular content item described by the recording document 404 is available. The head end 122, for instance, may execute the parser module 138 to locate data in the recording document 404 that describes the particular content item, which is illustrated at block 412 of FIG. 4 as “content description 414”. The content description 414 (i.e., the descriptive data) is then compared with the EPG data 122(m) to find a match. For example, the <program>, <service>, and <airing> elements may be compared with the EPG data 122(m) to find a particular content item which most satisfies those elements. Thus, the parser module 138, when executed, may determine how to record the particular content item that is described by the recording document by cross-referencing the content description 414 with the EPG data 122(m). In an implementation, the head end 112 utilizes minimum search field requirements before querying the database that contains EPG data 122(m) (block 412). For example, specific combinations of search criteria, when included in a recording document, may result in a failure in the query (block 412) due to insufficient amount of information (e.g., elements) to locate the particular content item. For instance, a recording document that only specifies a <service> (e.g., a broadcast channel) may be considered as invalid unless a corresponding <program> and/or <airing> is provided. The following is a listing of exemplary legal combinations of the three elements previously described: <program> (e.g., record this program anytime it is streamed, on any service); <program>, <service> (record this program anytime it is streamed from a specified service); <program>, <airing> (record this program at this time from any service); <program>, <service>, <airing> (record this program at this time from this service); and <service>, <airing> (record the named service at the given time). Although three elements are described, a variety of other elements and combinations thereof may also be included in the recording document 404 to locate a particular content item. Through use of elements and different combinations of the elements, for example, search criteria may be broadly or narrowly specified depending upon the desired implementation. For instance, a fan website may post a recording document for recording any episode of a particular television program no matter what time it is broadcast and no matter which channel broadcasts the television program. Such a recording document may specify the title of the television program (e.g., <program>) without supplying any other additional elements. In another instance, a website provided by a particular content broadcaster may supply a recording document that specifies episodes that are broadcast by that particular content broadcaster and does not wish to include episodes that are broadcast by rival broadcasters. In this instance, the recording document specifies the title of the television program (e.g., <program>) and the broadcaster (e.g., <service>). Although some examples of search criteria have been described, a variety of other search criteria may also be specified in a recording document. For example, the recording document may specify alternative matching attributes, such as “(<program> and <service>) or (<service> and <airing>)”. Additionally, each of the elements may be specified in a variety of ways. For instance, a target service may be specified by call sign, name, affiliate, and so on. Thus, the recording document may flexibly describe search criteria as contemplated by a creator of the recording document. The search criteria (i.e., elements) may also be processed so that the recording document is transportable between users having different respective content providers. For example, users may receive content through different channel lineups, the users may be located in different time zones, and so on. Time-based search criteria, for instance, may be specified using any time-zone and then normalized to a local time-zone when parsed. In another instance, the search criteria may be restricted to within a particular offset from coordinated universal time (UTC). Multiple criteria may be specified in this way so one time can be specified that applies only to Pacific Standard Time (PST) and Eastern Standard Time (EST), for example, and another time set for Mountain Standard Time (MST) and Central Standard Time (CST). In a further instance, a search “window” can be specified to allow the episode to be matched within a specific range of time around the time specified. If the particular content item is available, then the head end adds a content reference 418 to the particular content item in the recording list 140 (block 416). The content reference 418, for instance, may specify a broadcast channel and time to record the referenced content item, map to a memory location of the particular content item in a database 114 of FIG. 1 at the head end 112, and so on. At block 420, the head end 112 causes the client 104 to record the particular content item referenced in the recording list 140. For example, the head end 112 may execute the parser module 138 to communicate the content reference 418 over the network 106 to the client 104. The navigation module 134, upon receipt of the content reference 418, records the particular content item to the database 130 as specified by the content reference 418. Thus, in this example, the remote device 142 is able to cause the client 104 to record a particular content item without direct interaction with the client 104. FIG. 5 is an illustration of a system 500 in an exemplary implementation in which a graphical user interface (GUI) 502 is provided by the recording module 228 to dynamically generate the recording document 136 based on user input. In the previously described procedure 400 of FIG. 4, the recording document 404 was preconfigured and obtained to record a particular content item. The recording document may also be dynamically generated based on user input to describe a particular content item for recording. The remote device 142, for example, includes the recording module 228. The recording module 228, when executed on the remote device 142, provides an output for display on a display device 504 of the GUI 502. The GUI 504 in this example provides an interface for entering keyword search elements which may be utilized to locate a particular content item. For instance, the user may utilize an input device to enter a portion of a title and actors in the particular content item, such as “Godfather” 506, “Pacino” 508, and “DeNiro” 510. The recording module 228 utilizes these elements to form the recording document 136. The recording document 136 is then communicated over the network 106 to the distribution server 118 and parsed by the parser module 138 as previously described to determine if the described particular content item of the recording document 136 is available. In this example, the elements “Godfather” 506, “Pacino” 508 and “De Niro” 510 are utilized to determine if the particular content item “Godfather II” is available by finding a content item described in the EPG data 122(m) of FIG. 1 that satisfies each of these elements. In another implementation, a “best match” may be performed so that the content item described in the EPG data 122(m) which satisfies the most elements in the recording document 136 is reported to the user via the GUI 504. For example, Godfather II may not be available based on a query of the EPG data 122(m). However, the movie Godfather I, which satisfies the elements “Godfather” 506 and “Pacino” 508 may be available. Therefore a result of the query, which indicates the availability of Godfather I, is output via the GUI 504 so that the user can decide whether to record that particular content item. FIG. 6 is an illustration of a system 600 in an exemplary implementation in which the recording module is executed to examine a textual description of content to dynamically generate a recording document. In the system 500 of FIG. 5, the recording document 136 was dynamically generated based on user input. The recording document 136 may also be dynamically generated without user input. The client 104, for instance, may be configured as a set-top box 126 that is communicatively coupled to the display device 128. The client 104 executes the navigation module 134 to access a textual description of a particular content item over the network 106, which in FIG. 6 is illustrated as a content review 602 that is available from a web site. The user, upon reading the content review 602, may desire to record the particular content item described in the review. In this instance, however, the content review 602 does not include a preconfigured recording document as previously described in relation to FIG. 3. Therefore, the client 104 executes a recording module 604 to dynamically generate the recording document 136 based on the content review 602. The recording module 604, for example, may be executed to examine the content review 602 to find one or more words which describe the particular content item. In an implementation, the recording module 604 compares words in the content review 602 with a database 606 of descriptive words which may be utilized to describe content, such as names of broadcast channels, titles, actors, and so on. For instance, the recording module 604, when executed, locates the words “hardball” 608, “Chris Matthews” 610, and “MSNBC” 612 (MSNBC is a trademark of MSNBC Cable L.L.C. of New York, N.Y.). The recording module 604 then generates a recording document 614 and communicates it over the network 106 to a parser module 616 that is executable on another client 618. The parser module 616, when executed on the other client 618, compares the recording document 614 with an EPG 620 to determine if the particular content item described in the recording document 614 is available, and if so, causes a navigation module 622 to record the particular content item as content 624(p), where “p” can be any integer from one to “P”, in the database 626. In another implementation, the recording module 604 and the parser module 616 are executed to directly compare words 608-612 in the content review 602 with the EPG 124 that is stored on the client 104. In other words, the EPG 124 (and more particularly the EPG data that is utilized to configure the EPG 124) provides the database 606. In this implementation, the recording module 604 does not wait until after the recording document 608 is completely generated to perform the comparison, but rather compares words 608-612 with the EPG 124. It should be noted that in the system 600 of FIG. 6, the client 104 executes the recording module 604 to generate the recording document 136. Another client 618 executes the parser module 616 to determine if the particular content item is available based on another EPG 620 that is stored locally on the other client 618. Thus, the content recordation techniques may also be utilized for interaction between clients 104, 618 without directly involving the head end 112 of FIG. 1. Further discussion of client execution of the parser module may be found in relation to the following figure. FIG. 7 is a flow diagram depicting a procedure 700 in an exemplary implementation in which a client dynamically generates a recording document that is utilized to determine availability of a particular content item for recording by the client. At block 702, the client displays a textual description of a particular content item. A variety of textual descriptions may be displayed, such as the content review 602 of FIG. 6, an email, a text message communicated from another client, and so on. At block 704, the client receives an input to active a recording module. For example, the client may provide an icon for selection by the user, a drop-down menu for activation of the recording module, and so on. At block 706, the recording module, when executed, examines the text to locate descriptions of the particular content item. For instance, the recording module may first examine the text to locate words which are typically used to describe the <program>, <service>, and <airing> elements that were previously described. The recording module may also locate other words which describe the particular content item, such as actor, output duration of the content, genre, start time, stop time, plot, and so on. At block 708, the recording module generates a recording document that includes the located descriptions of the particular content item. The recording document, for instance, may be configured according to an XML recording schema that is understood by the parser module. The recording module then passes the recording document to the parser module (block 710). At block 712, the parser module queries EPG data to locate the particular content item. In a first scenario, the parser module is executed on the client to query an EPG that is stored locally on the client. In a second scenario, the parser module is executed on the client to query EPG data that is stored at the head end, such as the EPG data 122(m) stored in the database 120 at the head end 112 of FIG. 1. At decision block 714, a determination is made as to whether the located content item conflicts with another content item in the recording list. For example, the recording list may be configured for implementation by a DVR that is capable of recording a single content item at any one point in time. Therefore, the parser module may be executed to flag conflicts in the recording list so that the referenced content items are recorded as desired. If there is a conflict (block 714), a message is sent to the user (block 716) so that the user may decide which of the conflicting content items is to be recorded, if any. If the located content item does not conflict with another content item in the recording list (block 714), a determination is made as to whether the client is authorized to record the content (block 718). For example, the parser module may be executed to determine from the client state data 220(l) stored at the distribution server 118 of FIG. 2 whether the client is permitted to access the referenced content item. The client state data 220(l), for instance, may be utilized to indicate a variety of conditional access rights, such as parental blocks, digital rights management (DRM), content subscriptions, and so on. If the client is authorized to record the content (block 718), then the located content item is added to a recording list (block 720). For instance, a reference to the located content item may be added which describes how to record the located content item, such as date, time, and channel of a broadcast of a television program, a memory location, and so on. The recording list may then be utilized to cause the navigation module to record the added content item (block 722). CONCLUSION Although the invention has been described in language specific to structural features and/or methodological acts, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary forms of implementing the claimed invention. | <SOH> BACKGROUND <EOH>Users are continually exposed to an ever increasing variety of clients that provide network access, such a set-top boxes, wireless phones, computers, and so on. A user of a set-top box, for instance, may view traditional television programming obtained from a broadcast network for display on a television, as well as order pay-per-view movies, receive video-on-demand (VOD), play “live” video games, and so on. Likewise, a user of a wireless phone may place and receive traditional telephone calls, as well as read email, download digital music, and so on. Another such example is a digital video recorder (DVR). A DVR typically includes non-volatile storage (e.g., a hard disk) that enables the user to record desired content. DVR's also offer control functionality, such as the ability to pause content that is currently being broadcast and allows viewers to watch the content, while still in progress, from the point it was paused. The DVR plays back the content from storage, starting at the pause event, while continuing to record the currently-broadcast content. Additionally, the DVR may support other control functions, such as rewinding, fast forwarding a stored program, slow motion playback, and the like. To record content using a DVR, a user was typically required to directly interact with the DVR itself. In some instances, the user could configure the DVR to record related content by specifying parameters to be matched with those of available content to locate potentially desirable content. For example, the user could specify the title of a television program so that the DVR would record each television program having that title. However, the user was not assured that the DVR would record a particular content item of interest. In other words, the user could not be certain that the potentially desirable content recorded by the DVR corresponded with the actual content the user wished to record. For example, although the DVR may be configured to record a particular television program, the DVR might fail to record a special regarding the actors in that particular television program. Therefore, when the user was located “away” from the DVR, the user could not cause the DVR to record the particular content item, even if the user had access to one or more of the clients that provide network access as previously described. Accordingly, there is a continuing need for improved content recordation techniques. | <SOH> SUMMARY <EOH>Content recordation techniques are described. The content recordation techniques may be utilized when the user is local to and remote from the client. For example, a user, when remotely located from a client configured as a digital video recorder (DVR), interacts with a remote device that is configured as a wireless phone. The user utilizes the wireless phone to access a review of a television program via the Internet. Based on the review, the user invokes a recording document that is embedded in the review to be communicated to the remote client. The recording document describes the television program, such as by describing a title, actors, broadcast time, service (e.g., channel) that broadcasts the television program, and so on. Upon receipt of the recording document, the remote client executes a parser module to examine the recording document to determine if the television program described in the recording document is available for being recorded by the remote client. For instance, the recording document may be compared with electronic program guide (EPG) data that is received from a head end, EPG data service, and so on. The EPG data may be utilized to determine if the television program is available. The EPG data may also be utilized to determine how the television program is to be recorded, such as by supplying a channel and broadcast start time. If the television program is available, a reference to the television program is added to a recording list based on the EPG data. For example, the broadcast channel and the broadcast start time may be added to the recording list. The recording list is then utilized by the remote client to cause the client to record the content. In another instance, the recording document may cause the head end to cause the client to record the content, such as by examining EPG data stored at the head end to determine if the content is available for recording. If so, the head end causes the client the record the content. In a further instance, the recording document may cause the head end itself to record the content, such as in a network digital video recorder (NDVR) scenario. | 20040715 | 20150428 | 20060601 | 92238.0 | H04N5445 | 0 | SHANG, ANNAN Q | CONTENT RECORDATION TECHNIQUES | UNDISCOUNTED | 0 | ACCEPTED | H04N | 2,004 |
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10,891,598 | ACCEPTED | Token device that generates and displays one-time passwords and that couples to a computer for inputting or receiving data for generating and outputting one-time passwords and other functions | A token device that generates and displays one-time passwords and couples to a computer for inputting or receiving data for generating and outputting one-time passwords and performing other functions is provided. The token includes an interface for coupling to a computer. The token may also be coupled to any network that the computer may be connected to, when coupled to the computer. Data and information may be transmitted between the computer and token, and between the network and token, via the computer and interface. The data and information may include one-time password seeding, file transfer, authentication, configuration and programming of the token. The token must be seeded to generate and display one-time passwords. An original, or seed, value is loaded into the token. One-time passwords are subsequently generated or calculated, or both, from the seed value. Seeding of the token involving a counter, time, or time-related functions, may allow synchronization of the token with such functions. The token may support different authentication methods. | 1. A token device for generating and displaying password data comprising: a body portion; and a display portion, the display portion including a display for displaying alphanumeric characters and an interface for coupling the token to a computer. 2. The token device of claim 1 wherein the display portion displays alphanumeric characters representing password data generated by the token device. 3. A token device for generating and displaying password data comprising: a body portion, the body portion including, a processor for processing data; a memory for storing data, the memory coupled to the processor; and a display portion, the display portion including, a display for displaying alphanumeric characters, the display coupled to the processor for displaying data output by the processor; and an interface for coupling the token to a computer, for transmitting data between the processor and computer. 4. The token device of claim 3 wherein the display portion is rotatably coupled to the body portion. 5. The token device of claim 4 wherein the display displays alphanumeric characters representing password data output by the processor. 6. The token device of claim 5 wherein the display is configured to display at least five alphanumeric characters representing password data output by the processor. 7. The token device of claim 3 further including a data cable configured to couple the interface to the computer for transmitting data between the token device and computer. 8. A token device for generating and displaying password data comprising: a body portion, the body portion including, a processor for processing data, the processor contained within the body portion; a memory for storing data, the memory coupled to the processor and contained within the body portion; and a display portion rotatably coupled to the body portion, the display portion including, a display for displaying alphanumeric characters, the display coupled to the processor for displaying data output by the processor; and an interface for coupling the token to a computer, the interface coupled to the processor for transmitting data between the processor and computer. 9. The token device of claim 8 wherein the display is configured to display at least five alphanumeric characters representing password data output by the processor. 10. The token device of claim 9 wherein the display comprises a selected one of a liquid crystal display and a light emitting diode display. 11. The token device of claim 8 further including a data cable configured to couple the interface to the computer for transmitting data between the token device and computer. 12. The token device of claim 8 wherein the processor generates new password data at predetermined time intervals. 13. The token device of claim 8 wherein the processor generates new password data upon receipt of data from the computer, and wherein the new password data is displayed on the display. 14. The token device of claim 13 wherein the token device transmits the new password data to the computer via the data cable. 15. The token device of claim 14 wherein the computer is connected to a least one computer of a computer network. 16. The token device of claim 15 wherein the processor generates new password data upon receipt of data from a least one computer of the computer network that the token is connected to via the computer and data cable, and wherein the new password data is displayed on the display. 17. The token device of claim 16 wherein the token device transmits the new password data to least one computer of the computer network. 18. A method for generating and outputting one-time passwords, the method comprising; providing a token device, the token device including, a body portion including a processor and a memory; and a display portion, the display portion including a display for displaying alphanumeric characters representative of one-time password data generated by the processor, and an interface for coupling the token to a computer, for transmitting data between the token and computer; loading a value into the memory; feeding the value into the processor for generating data representative of one-time passwords; and generating data representative of a one-time password. 19. The method of claim 18 wherein the data representative of a one-time password is displayed on the display. 20. The method of claim 18 further comprising: providing a data cable configured to couple the interface to the computer for transmitting data between the token device and computer, and wherein the computer is connected to a least one computer of a computer network 21. The method of claim 20 further comprising: transmitting data representative of a one-time password from the token device to the computer. 22. The method of claim 21 further comprising: transmitting data representative of a one-time password from the token device to a computer of the computer network. | CROSS-REFERENCE TO RELATED APPLICATIONS This application is a non-provisional application of Provisional Application No. 60/488,585, filed on Jul. 17, 2003. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data authentication methods and systems and, more particularly, to a token device that generates and displays one-time passwords and couples to a computer for inputting or receiving data for generating and outputting one-time passwords and performing other functions. 2. Background Information The role of computers in our society has grown dramatically over the last few decades. During the past decade, networking technology and the Internet have grown and matured. The Internet is fast becoming the primary platform for global communication and commerce. However, the ease of communication and information sharing that has driven the growth of the Internet has also made it more difficult to ensure the security of Internet transactions and to maintain the privacy of information accessible over the Internet. To maintain security and privacy, many transactions and communications taking place over the Internet and other networked environments require that a user authenticate him or herself in order to access information or to conduct transactions. For example, an online brokerage typically requires a user to authenticate him or herself prior to accessing their account or trading stocks. Authentication refers to the method of proving the identity of the user. To be authenticated, the user typically presents a unique credential to a website or network they desire to access. This credential is usually comprised of a username and a secret password. Both the username and secret password may be established by the user. Alternatively, the username may be assigned to the user by an administrator of the website, or a similar entity, and the user may generate their secret password. Other known alternative methods may also be used to generate the username and password. Static usernames and passwords are the most common method of authentication in the networked environment. However, static usernames and passwords are prone to several types of attacks and impersonations such as “Trojan horses” and “dictionary attacks.” A user's static username and password can also be misappropriated through networking sniffers, password hacking programs, and other less sophisticated methods such as guesswork. For example, a user may have established a “weak” password using his date of birth or the name of his spouse as the password which may be easily guessed. To strengthen authentication methods and prevent the types of attacks and impersonations described above, the network security industry has develop methods of authentication that go beyond simple username and password schemes. These methods may be categorized as challenge and response, Public Key Infrastructure or PKI, and One-Time-Password or OTP. These methods make impersonation attacks more difficult by creating longer and dynamic passwords. Longer passwords make it more difficult to guess the password, while dynamic passwords allow the authorized user to use the same username, but a new password each time. Each new password is generated by hardware or software commonly referred to as a token device, or “token”. The token may be designed to display dynamic passwords. When authentication is needed, the user simply enters the dynamic password displayed by the token at that time. These token values are often supplemented with a secret PIN code know only to the user. A secret PIN code may also be used to activate the token in order to display the dynamic password. These authentication methods have the potential to replace simple username and password schemes in the future. BRIEF SUMMARY OF THE INVENTION The present invention comprises a token device that generates and displays one-time passwords. The token device, hereinafter token, couples to a computer for inputting or receiving data for generating and outputting one-time passwords and performing other functions. The token includes an interface for coupling to a computer. The token may be coupled to any network that the computer may be connected to. Data may be transmitted between the computer and token and between the network and token, via the computer and interface when the token is coupled to the computer and when the computer is connected to the network. The data may include one-time password seeding, authentication, token configuration, programming of the token, and file transfer. The token may be multi-functional and capable of generating and displaying one-time passwords as well as performing other functions, such as challenge and response, PKI, digital certificate, and/or biometric. The token must first be seeded to generate and display one-time passwords. Seeding is the process of loading an original, or seed, value into a token. From the seed value one-time passwords are subsequently generated or calculated, or both. There are many ways to load seed values into the token. The token can be seeded when it is coupled to a computer via the interface. For example, seed values can be loaded into the token from the computer via the interface. Seed values may also be sent to the token from a network that the computer is connected to. The seed values may be encrypted or in clear text. The seed values may also be generated, derived and/or calculated from PKI keys pairs and/or digital certificates. Some methods of seeding involve a counter, time, or time-related functions. In these cases, when the token is coupled to a computer, it may allow synchronization operations to synchronize the token with such counter, time, or time related functions. The token may support a single authentication method or a combination of different authentication methods. These authentication methods include one-time password, challenge response, PKI, digital certificate, and/or biometric. The token may also perform such functions while coupled with a computer and thus to a network that the computer is connected to. BRIEF DESCRIPTION OF THE DRAWINGS The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which: FIG. 1 is a schematic diagram showing an embodiment of the token device of the present invention coupled to a computer and showing the computer coupled to a computer network; FIG. 2 is a top, schematic view of a preferred embodiment of a token device of the invention showing a display portion rotatably coupled to a body portion of the token device invention; FIG. 3 is a top, schematic view of a preferred embodiment of the token device of the invention; and FIG. 4 is a top, schematic view showing token device of the invention in a closed position. DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes presently contemplated by the inventors of carrying out the invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein. Referring to the drawing in FIGS. 1-4, the invention comprises a token device, or token, shown generally at 10. The token includes a body portion 12 and a display portion 14. The display portion may optionally be pivotally, rotatably, or similarly coupled to the body portion 12. An on-board processor 16 and memory 18 for processing and storing data may be contained in the body portion 12. The processor 16 is preferably capable of generating and outputting data that may be utilized as one-time passwords. The one-time passwords output by the processor 16 may be displayed on a display 20 of the display portion 14. A one-time password output by the processor 16 may comprise a string of alphanumeric characters. Preferably, the string of alphanumeric characters ranges from six to eight characters. The token 10 may be provided with a unique string of information, or data, for identifying that particular token 10. The unique string of information may be stored in the token's memory 18. A copy of the unique string of information may reside at a remote location, such as a server 31 of a network 34. The display portion 14 includes a display 20. The display 20 preferably comprises either a Liquid Crystal Display (LCD) or Light Emitting Diode (LED) display that is electronically coupled to the processor 16 using known methods. The display 20 is preferably capable of displaying a plurality of numeric or alphanumeric characters, shown generally at 22 that can be viewed through a window 23. The display portion 14 may be rotatably coupled to the body portion 12. Rotatably coupling the display portion 14 to the body portion 12 may help to prevent damage to the display 20 and may provide a token 10 having reduced dimensions. The display portion 14 includes an interface 26 for coupling the token 10 to a data port 28 of a computer, shown generally at 30. The interface 26 may be provided in any suitable known data interface configuration. Preferably, the interface 26 is provided in a known Universal Serial Bus (USB) configuration for coupling to a known USB port 28 of the computer 30 via a USB data cable 32. Additionally, the computer 30 may be coupled to a computer network 34, such as the Internet. Thus, data may be transmitted between the token 10 and computer 30, via the data cable 32, and data may be transmitted between the token 10 and network 34, via the data cable 32 and computer 30. Alternatively, the token 10 may optionally function externally of the network 34 and without coupling to the computer 30. The display portion 14 may further include an activation button 24. The activation button 24 may be provided for activating the display 20, to limit power consumption or increase the life of the display 20, for example. The token 10 is capable of receiving, generating, and outputting data and information. This data and information may include one-time password seeding, file transfer, authentication, configuration and programming of the token 10. The multi-functional token 10 is capable of generating and displaying one-time passwords as well as performing other functions. The token 10 must first be seeded to generate and display one-time passwords. Seeding is the process of loading an original, or seed, data value into the token 10. From the seed value one-time passwords are subsequently generated or calculated, or both. There are many ways to load seed data values into the token 10. One preferred method of seeding the token 10 includes first coupling the token 10 to the computer 30 via the data cable 32. The seed data values are then sent to the token 10 and stored in memory 18 and processed by the token's processor 16. Alternatively, seed values are then sent to the token 10 from a server 31 of the network 34 via the computer 30 and data cable 32. There are a number of known methods for transmitting and loading seed values into the token 10 that are readily apparent to those of ordinary skill in the art. The seed data values may, or may not, be encrypted. The seed values may also be generated, derived and/or calculated from PKI keys pairs and/or digital certificates. Some methods of seeding the token 10 involve a counter, time, or time-related functions. In these cases, when the token 10 is coupled to the computer 30, it may allow synchronization operations to synchronize the token 10 with such counter, time or time related functions. The token 10 may support a single authentication method or a combination of different authentication methods. These methods include one-time password, challenge response, PKI, digital certificate, and/or biometric. The token 10 may also perform such functions while coupled with the computer 30 and thus to any network 34 that the computer 30 is connected to. Thus, there has been described a token device that generates and displays one-time passwords and couples to a computer for inputting or receiving data for generating and outputting one-time passwords and performing other functions. The token may also be coupled to any network that the computer may be connected to, when coupled to the computer. Data and information may be transmitted between the computer and token, and between the network and token, via the computer and interface. The data and information may include one-time password seeding, file transfer, authentication, configuration and programming of the token. Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to data authentication methods and systems and, more particularly, to a token device that generates and displays one-time passwords and couples to a computer for inputting or receiving data for generating and outputting one-time passwords and performing other functions. 2. Background Information The role of computers in our society has grown dramatically over the last few decades. During the past decade, networking technology and the Internet have grown and matured. The Internet is fast becoming the primary platform for global communication and commerce. However, the ease of communication and information sharing that has driven the growth of the Internet has also made it more difficult to ensure the security of Internet transactions and to maintain the privacy of information accessible over the Internet. To maintain security and privacy, many transactions and communications taking place over the Internet and other networked environments require that a user authenticate him or herself in order to access information or to conduct transactions. For example, an online brokerage typically requires a user to authenticate him or herself prior to accessing their account or trading stocks. Authentication refers to the method of proving the identity of the user. To be authenticated, the user typically presents a unique credential to a website or network they desire to access. This credential is usually comprised of a username and a secret password. Both the username and secret password may be established by the user. Alternatively, the username may be assigned to the user by an administrator of the website, or a similar entity, and the user may generate their secret password. Other known alternative methods may also be used to generate the username and password. Static usernames and passwords are the most common method of authentication in the networked environment. However, static usernames and passwords are prone to several types of attacks and impersonations such as “Trojan horses” and “dictionary attacks.” A user's static username and password can also be misappropriated through networking sniffers, password hacking programs, and other less sophisticated methods such as guesswork. For example, a user may have established a “weak” password using his date of birth or the name of his spouse as the password which may be easily guessed. To strengthen authentication methods and prevent the types of attacks and impersonations described above, the network security industry has develop methods of authentication that go beyond simple username and password schemes. These methods may be categorized as challenge and response, Public Key Infrastructure or PKI, and One-Time-Password or OTP. These methods make impersonation attacks more difficult by creating longer and dynamic passwords. Longer passwords make it more difficult to guess the password, while dynamic passwords allow the authorized user to use the same username, but a new password each time. Each new password is generated by hardware or software commonly referred to as a token device, or “token”. The token may be designed to display dynamic passwords. When authentication is needed, the user simply enters the dynamic password displayed by the token at that time. These token values are often supplemented with a secret PIN code know only to the user. A secret PIN code may also be used to activate the token in order to display the dynamic password. These authentication methods have the potential to replace simple username and password schemes in the future. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention comprises a token device that generates and displays one-time passwords. The token device, hereinafter token, couples to a computer for inputting or receiving data for generating and outputting one-time passwords and performing other functions. The token includes an interface for coupling to a computer. The token may be coupled to any network that the computer may be connected to. Data may be transmitted between the computer and token and between the network and token, via the computer and interface when the token is coupled to the computer and when the computer is connected to the network. The data may include one-time password seeding, authentication, token configuration, programming of the token, and file transfer. The token may be multi-functional and capable of generating and displaying one-time passwords as well as performing other functions, such as challenge and response, PKI, digital certificate, and/or biometric. The token must first be seeded to generate and display one-time passwords. Seeding is the process of loading an original, or seed, value into a token. From the seed value one-time passwords are subsequently generated or calculated, or both. There are many ways to load seed values into the token. The token can be seeded when it is coupled to a computer via the interface. For example, seed values can be loaded into the token from the computer via the interface. Seed values may also be sent to the token from a network that the computer is connected to. The seed values may be encrypted or in clear text. The seed values may also be generated, derived and/or calculated from PKI keys pairs and/or digital certificates. Some methods of seeding involve a counter, time, or time-related functions. In these cases, when the token is coupled to a computer, it may allow synchronization operations to synchronize the token with such counter, time, or time related functions. The token may support a single authentication method or a combination of different authentication methods. These authentication methods include one-time password, challenge response, PKI, digital certificate, and/or biometric. The token may also perform such functions while coupled with a computer and thus to a network that the computer is connected to. | 20040715 | 20090414 | 20050120 | 66890.0 | 3 | FIELDS, COURTNEY D | TOKEN DEVICE THAT GENERATES AND DISPLAYS ONE-TIME PASSWORDS AND THAT COUPLES TO A COMPUTER FOR INPUTTING OR RECEIVING DATA FOR GENERATING AND OUTPUTTING ONE-TIME PASSWORDS AND OTHER FUNCTIONS | SMALL | 0 | ACCEPTED | 2,004 |
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10,891,837 | ACCEPTED | Article footwear with removable heel pad | An article of footwear includes a sole assembly, an upper secured to the sole assembly, a heel counter secured to the upper, and a heel pad removably attached to an inner surface of the heel counter. | 1. An article of footwear comprising, in combination: a sole assembly; an upper secured to the sole assembly; a heel counter secured to the upper; and a heel pad removably attached to an inner surface of the heel counter. 2. The article of footwear of claim 1, wherein the heel pad includes at least one projection and the heel counter includes at least one recess, each recess receiving a corresponding projection. 3. The article of footwear of claim 2, wherein a peripheral edge of each projection is undercut so as to engage a corresponding recess in snap-fit fashion. 4. The article of footwear of claim 2, further comprising at least one fastener, each fastener configured to secure a projection within a corresponding recess. 5. The article of footwear of claim 4, wherein the fastener comprises a hook and loop fastener. 6. The article of footwear of claim 5, wherein a first portion of the hook and loop fastener is secured to the projection and a second portion of the hook and loop fastener is secured to the recess. 7. The article of footwear of claim 2, wherein each projection is of unitary construction with the heel pad. 8. The article of footwear of claim 1, wherein the heel pad includes at least one projection and the heel counter includes at least one aperture, each aperture receiving a corresponding projection. 9. The article of footwear of claim 8, wherein a peripheral edge of each projection is undercut so as to engage a corresponding aperture in snap-fit fashion. 10. The article of footwear of claim 8, wherein each projection is of unitary construction with the heel pad. 11. The article of footwear of claim 1, further comprising a collar secured to an interior surface of the heel counter, a lower edge of the collar positioned adjacent an upper edge of the heel pad. 12. The article of footwear of claim 11, wherein a rib is formed along an exterior surface of the collar proximate an upper edge of the collar, the rib extending along an upper edge of an upper of the sole assembly. 13. The article of footwear of claim 11, wherein the collar is formed of foam with a fabric lining. 14. The article of footwear of claim 1, wherein the heel counter includes a first recess on a medial side thereof and a second recess on a lateral side thereof, and the heel pad includes a first projection on a medial side thereof and a second projection on a lateral side thereof, the first recess receiving the first projection and the second recess receiving the second projection. 15. The article of footwear of claim 14, further comprising a first fastener securing the first projection within the first recess and a second fastener securing the second projection within the second recess. 16. The article of footwear of claim 1, wherein the heel counter is formed of plastic. 17. The article of footwear of claim 1, wherein the heel pad is formed of polyurethane. 18. The article of footwear of claim 1, wherein the heel pad is formed of EVA. 19. The article of footwear of claim 1, wherein the heel pad is formed of a plurality of layers laminated together. 20. The article of footwear of claim 1, further comprising a liner secured to an interior surface of the heel pad. 21. The article of footwear of claim 1, wherein one portion of the heel pad is formed of a first material and a second portion of the heel pad is formed of a second material. 22. The article of footwear of claim 21, wherein an outer portion of the heel pad has a hardness greater than a hardness of an inner portion of the heel pad. 23. The article of footwear of claim 1, wherein the heel pad has a varying thickness. 24. An article of footwear comprising, in combination: a sole assembly; an upper secured to the sole assembly; a heel counter secured to the upper and having a plurality of recesses; and a heel pad having a plurality of projections extending outwardly from an exterior surface thereof, each projection received by a corresponding recess to removably attach the heel pad to the heel counter. 25. The article of footwear of claim 24, further comprising at least one fastener, each fastener configured to secure a projection within a corresponding recess. 26. The article of footwear of claim 25, wherein the fastener comprises a hook and loop fastener, a first portion of the hook and loop fastener secured to the projection and a second portion of the hook and loop fastener secured to the recess. 27. The article of footwear of claim 24, further comprising a collar secured to an interior surface of the heel counter, a lower edge of the collar positioned adjacent an upper edge of the heel pad. 28. An article of footwear comprising, in combination: a sole assembly comprising an outsole, a midsole and an insole; an upper secured to the midsole; a heel counter secured to the upper and having a first recess on a medial side thereof and a second recess on a lateral side thereof; a heel pad having a first projection on a medial side thereof and a second projection on a lateral side thereof, the first recess receiving the first projection and the second recess receiving the second projection; a first fastener securing the first projection within the first recess; a second fastener securing the second projection within the second recess; and a collar secured to an interior surface of the upper, a lower surface of the collar adjacent an upper edge of the heel pad. 29. The article of footwear of claim 28, wherein each fastener comprises a hook and loop fastener, a first portion of each hook and loop fastener secured to a projection and a second portion of each hook and loop fastener secured to a recess. 30. An article of footwear comprising, in combination: a sole assembly comprising an outsole, a midsole and an insole; an upper secured to the midsole; a heel counter secured to the upper and having a first aperture on a medial side thereof and a second aperture on a lateral side thereof; a heel pad having a first projection on a medial side thereof and a second projection on a lateral side thereof, the first aperture receiving the first projection and the second aperture receiving the second projection; and a collar secured to an interior surface of the upper, a lower surface of the collar adjacent an upper edge of the heel pad. | FIELD OF THE INVENTION This invention relates generally to an article of footwear, and, in particular, to an article of footwear with a removable heel pad. BACKGROUND OF THE INVENTION Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper is often formed of leather, synthetic materials, or a combination thereof and comfortably secures the footwear to the foot, while providing ventilation and protection from the elements. The sole structure generally incorporates multiple layers that are conventionally referred to as an insole, a midsole, and an outsole. The insole is a thin cushioning member located within the upper and adjacent the sole of the foot to enhance footwear comfort. The midsole, which is traditionally attached to the upper along the entire length of the upper, forms the middle layer of the sole structure and serves a variety of purposes that include controlling potentially harmful foot motions, such as over pronation, attenuating ground reaction forces, and absorbing energy. In order to achieve these purposes, the midsole may have a variety of configurations, as discussed in greater detail below. The outsole forms the ground-contacting element of footwear and is usually fashioned from a durable, wear resistant material that includes texturing to improve traction. A heel counter is often provided at the rear of the footwear, and is contoured to wrap around the user's heel and along the sides of the footwear. The heel counter provides stability and support for the user's heel. The upper wraps around the rear exterior surface of the heel counter and is secured thereto, with a seam typically being provided in the upper at the rear of the heel counter. It is an object of the present invention to provide an article of footwear with a heel pad that reduces or overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain preferred embodiments. SUMMARY The principles of the invention may be used to advantage to provide an article of footwear with a removable heel pad that provides additional cushioning and support for a user's heel and ankle. In accordance with a preferred embodiment, an article of footwear includes a sole assembly, an upper secured to the sole assembly, a heel counter secured to the upper, and a heel pad removably attached to an inner surface of the heel counter. In accordance with another preferred embodiment, an article of footwear includes a sole assembly and an upper secured to the sole assembly. A heel counter is secured to the upper and has a plurality of recesses. A heel pad having a plurality of projections extends outwardly from an exterior surface thereof, with each projection being received by a corresponding recess to removably attach the heel pad to the heel counter. In accordance with a further preferred embodiment, an article of footwear includes a sole assembly having an outsole, a midsole and an insole. An upper is secured to the midsole, and a heel counter is secured to the upper. The heel counter has a first recess on a medial side thereof and a second recess on a lateral side thereof. A heel pad has a first projection on a medial side thereof and a second projection on a lateral side thereof. The first recess receives the first projection and the second recess receives the second projection. A first fastener secures the first projection within the first recess, and a second fastener secures the second projection within the second recess. A collar is secured to an interior surface of the upper, with a lower surface of the collar being adjacent an upper edge of the heel pad. In accordance with yet another preferred embodiment, an article of footwear includes a sole assembly having an outsole, a midsole and an insole. An upper is secured to the midsole, and a heel counter is secured to the upper. The heel counter has a first aperture on a medial side thereof and a second aperture on a lateral side thereof. A heel pad has a first projection on a medial side thereof and a second projection on a lateral side thereof. The first aperture receives the first projection and the second aperture receives the second projection. A collar is secured to an interior surface of the upper, with a lower surface of the collar being adjacent an upper edge of the heel pad. Substantial advantage is achieved by providing an article of footwear with a removable heel pad. In particular, preferred embodiments of the present invention help improve the fit about a user's heel, helping to maintain the heel in proper position, reduce relative movement of the user's heel, and improve comfort. Additionally, preferred embodiments of the present invention allow different heel pads to be installed in the article of footwear, allowing customization and/or optimization of the footwear. These and additional features and advantages of the invention disclosed here will be further understood from the following detailed disclosure of certain preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an article of footwear in accordance with a preferred embodiment of the present invention. FIG. 2 is perspective view, in exploded form, of a heel counter and heel pad of the article of footwear of FIG. 1. FIG. 3 is a perspective view of the heel counter, heel pad and collar (shown partially broken away) of FIG. 1, shown in assembled form. FIG. 4 is a section view of an alternative embodiment of the heel pad of FIG. 2. FIG. 5 is a section view of another alternative embodiment of the heel pad of FIG. 2. FIG. 6 is a section view of a portion of yet another alternative embodiment of the heel pad of FIG. 2. The figures referred to above are not drawn necessarily to scale and should be understood to provide a representation of the invention, illustrative of the principles involved. Some features of the article of footwear with a replaceable heel pad depicted in the drawings have been enlarged or distorted relative to others to facilitate explanation and understanding. The same reference numbers are used in the drawings for similar or identical components and features shown in various alternative embodiments. Articles of footwear with a replaceable heel pad as disclosed herein would have configurations and components determined, in part, by the intended application and environment in which they are used. DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS The present invention may be embodied in various forms. The following discussion and accompanying figures disclose an article of footwear 10 in accordance with the present invention. Footwear 10 may be any style of footwear including, for example, athletic footwear. Although the embodiments illustrated herein depict athletic footwear, the present invention is not to be restricted to athletic footwear, and could in fact be incorporated in any style of footwear. A preferred embodiment of an article of footwear 10 is shown in FIG. 1. Footwear 10 includes a sole assembly 12 and an upper 14 secured to sole assembly 12. Upper 14 may be secured to sole assembly 12 by any suitable means including, for example, stitching or an adhesive. Upper 14 forms an interior void that comfortably receives a foot and secures the position of the user's foot relative to sole assembly 12. As noted above, the configuration of upper 14 depicted here is suitable for use during athletic activities. Accordingly, upper 14 may have a lightweight, breathable construction that includes multiple layers of leather, textile, polymer, and foam elements adhesively bonded and stitched together. For example, upper 14 may have an exterior that includes leather elements and textile elements for resisting abrasion and providing breathability, respectively. The interior of upper 14 may have foam elements for enhancing the comfort of footwear 10, and the interior surface may include a moisture-wicking textile for removing excess moisture from the area immediately surrounding the foot. For purposes of general reference, footwear 10 may be divided into three general portions: a forefoot portion 11, a midfoot portion 13, and a heel portion 15. Portions 11, 13, and 15 are not intended to demarcate precise areas of footwear 10. Rather, portions 11, 13, and 15 are intended to represent general areas of footwear 10 that provide a frame of reference during the following discussion. Sole assembly 12 includes a midsole 16 to which upper 14 is secured, and an outsole 18, which may include a tread pattern (not shown) for added traction. An insole 19 (also referred to as a sock liner), seen in FIG. 3, may be positioned within upper 14 above midsole 16. Footwear 10 has a medial, or inner, side 20 and a lateral, or outer, side 22. Although sides 20, 22 apply generally to footwear 10, references to sides 20, 22 may also apply specifically to upper 14, sole assembly 12, or any other individual component of footwear 10. Unless otherwise stated, or otherwise clear from the context below, directional terms used herein, such as rear, rearwardly, front, forwardly, inwardly, outwardly, lower, downwardly, upper, upwardly, etc., refer to directions relative to footwear 10 itself. Footwear 10 is shown in FIG. 1 to be disposed substantially horizontally, as it would be positioned on a horizontal surface when worn by a wearer. However, it is to be appreciated that footwear 10 need not be limited to such an orientation. Thus, in the illustrated embodiment of FIG. 1, rearwardly is toward heel portion 15, that is, to the left as seen in FIG. 1. Naturally, forwardly is toward forefoot portion 11, that is, to the right as seen in FIG. 1, downwardly and lower are toward the bottom of the page as seen in FIG. 1, and upwardly is toward the top of the page as seen in FIG. 1. Inwardly is toward the center of footwear 10, and outwardly is toward the outer periphery of footwear 10. A heel counter 24, seen in FIGS. 2-3, is secured to an interior surface 26 of heel portion 15 of upper 14. In certain preferred embodiments, heel counter 24 is adhesively secured to interior surface 26 by way of cement or any other suitable adhesive. Heel counter 24 includes a first aperture 28 formed in medial side 20 and a second aperture 30 formed in lateral side 22. Heel counter 24 is preferably formed of a substantially rigid material, such as thermoplastic polyurethane, nylon, or any semi-rigid or rigid formable material. Heel counter 24 acts to provide stability and support about the user's heel and ankle. A heel pad 32 is removably positioned within footwear 10 and abutting an interior surface 34 of heel counter 24. In the illustrated embodiment, a first projection 36 is formed on medial side 20 of heel pad 32, and a second projection 38 is formed on lateral side 22 of heel pad 32. First and second projections 36 and 38 are received by first and second apertures 28, 30, respectively, such that heel pad 32 is removably attached to heel counter 24. Projections 36, 38 may be formed of unitary, that is, one-piece construction with heel pad 32, or they may be separate elements secured to heel pad 32 by adhesive or other suitable fastening means. It is to be appreciated that the removable heel pad 32 need not necessarily have two projections, nor does heel counter 24 necessarily require two apertures into which the projections extend and in which they are received. A single projection and mating aperture or more than two projections and mating apertures may be formed in heel pad 32 and heel counter 24, respectively. Further, it is to be appreciated that the size and shape of the projections and mating apertures may vary as well. In the illustrated embodiment, projections 36, 38 and apertures 28, 30 have a generally L-shape and inverted L-shape configurations. However, it is to be appreciated that these configurations are merely illustrative and any other shapes are considered to be within the scope of the present invention. In certain preferred embodiments, a collar 40 is positioned adjacent interior surface 26 of heel portion 15 of upper 14 above heel counter 24 and heel pad 32, as seen in FIG. 3. Collar 40 may be adhesively secured to upper 14 by way of cement, epoxy or other suitable adhesive. It is to be appreciated that collar 40 may be secured to upper 14 by stitching or any other suitable means, which will become readily apparent to those skilled in the art, given the benefit of this disclosure. In the illustrated embodiment, a rib 42 is formed on an exterior surface 44 of collar 40 proximate an upper edge 46 thereof. Rib 42 is positioned adjacent an upper edge 48 of heel portion 15 of upper 14. Collar 40 helps to capture heel pad 32 and maintain it in proper position within upper 14. In a preferred embodiment, an interior surface 50 of collar 40 is substantially flush with an interior surface 52 of heel pad 32. Front lower ends 53 of collar 40 wrap down along inner surface 26 of upper 14 and extend beneath insole 19 on the medial 20 and lateral sides 22 of footwear 10. Insole 19 is positioned above a lower surface 55 of heel pad 32. In a preferred embodiment, a recess 54 is formed in a rear area of upper edge 56 of heel pad 32. A recess 57 is similarly formed in a rear upper edge 59 of heel counter 24. A mating tab 58 is formed on a rear lower edge 60 of collar 40. Tab 58 is configured to mate or nest in recess 54 so as to help register heel pad 32 within upper 14. To remove heel pad 32, a user pulls insole 19 upwardly away from heel pad 32, and pulls heel pad 32 out from engagement with heel counter 24 and from beneath collar 40. Heel pad 32 is inserted in the reverse order. Thus, the user positions heel pad 32 within heel portion 15 of upper 14, pressing projections 36, 38 into the corresponding recesses 28, 30 and ensuring that upper edge 56 of heel pad 32 is positioned beneath collar 40. Insole 19 is then placed on top of heel pad 32. Another preferred embodiment of heel pad 32 is shown in FIG. 4. As noted above, projections 36, 38 may be unitary with heel pad 32 or separate elements secured thereto. In the illustrated embodiment, projection 38 on lateral side 22 is of unitary construction with heel pad 32 and projection 36 on medial side 20 is a separate element secured to heel pad 32 by way of a cement or other adhesive, or a separate material co-molded with the remainder of heel pad 32. While it is likely that projections 36, 38 on a particular heel pad 32 will both be of unitary construction or both be separate elements, it is not necessary that they both have the same construction. As illustrated here, a liner 62 is secured to an interior surface 64 of heel pad 32. Liner 62 may be secured to heel pad 32 by way of cement or other suitable adhesive. Additionally, heat and pressure may be applied to liner 62 and heel pad 32 to ensure a good bond therebetween. Liner 62 acts to provide a smooth comfortable surface for the foot of the user. Liner 62 may be formed of a soft fabric such as nylon, polyester, synthetic leather, or any soft fabric. In a preferred embodiment, peripheral edges of the projections may be undercut. As illustrated in FIG. 4, a peripheral edge 66 of projection 38 on lateral side 22 is shown to be undercut so as to be received in aperture 30 in snap-fit fashion, thereby enhancing the attachment of heel pad 32 to heel counter 24. Heel pad 32 advantageously can be customized to provide extra support and cushioning about the user's ankle and heel. The thickness of heel pad 32 can be varied to optimize its fit. Heel pad 32 could, for example, be custom fit to very closely follow the profile of a particular individual's foot. In other embodiments, a generalized fit can be made based on the shape of a standard or average foot structure. Thus, the shape of heel pad 32 may be customized to more accurately reflect the shape of a user's foot, particularly about the ankle of a user. For example, as seen in FIG. 4, heel pad 32 is thicker in positioned inwardly of first and second projections 36, 38 so as to provide extra cushioning about the user's ankle to reduce or eliminate the gaps typically formed between the user's ankle and the interior surface of footwear 10. Further, since heel pad 32 is removably attached to heel counter 24, a user can swap heel pad 32 out and replace it with another heel pad. Thus, a user, or any other individual, could insert a heel pad 32 with a desired construction into footwear 10, and easily replace that pad with a pad of another construction if so desired. This construction allows footwear 10 to easily be customized for particular individuals, particular conditions, or for any other parameter. Heel pad 32 is preferably formed of a soft, resilient material so as to provide a comfortable feel for the user's heel and ankle. Heel pad 32 may be formed of, for example, a thermoformed ethylene vinyl acetate (EVA) foam, or a poured polyurethane foam (which may include a foaming agent), any plastic that could be made into a foam, or any pressurized or inflatable bladders, which can be independent elements or incorporated into the foam component. Other suitable materials for heel pad 32 will become readily apparent to those skilled in the art, given the benefit of this disclosure. As illustrated in FIG. 5, heel pad 32 may include a first portion 68 formed of a first material and a second portion 70 formed of a second material. In certain preferred embodiments, first portion 68 could be formed of a material having a first density of hardness, and second portion 70 could be formed of a material having a second density or hardness, thereby providing different levels of support for different areas of heel pad 32. For example, as illustrated in FIG. 5, first portion 68 is an outer layer and second portion 70 is an inner layer, with first portion 68 having a hardness greater than a hardness of second portion 70. It is to be appreciated that any combination of materials for first portion 68 and second portion 70 is possible. Additionally, it is to be appreciated that first portion 68 and second portion 70 need not be an inner and outer layer, respectively, but rather, could form any portion of heel pad 32. Thus, it is to be appreciated that in certain preferred embodiments, heel pad 32 may be a multi-layer laminate of desired materials, such as different foams, and such a laminate is not limited to an inner layer and outer layer as described above in connection with FIG. 5. Heel pad 32 could be formed of a laminate of three or more layers of any desired materials. Another preferred embodiment is shown in FIG. 6, in which projection 38 is received in a recess 72 formed in heel counter 24. Although only projection 38 and recess 72 are illustrated here, kit is to be appreciated that a recess could also be formed in medial side 20 of heel counter 24 to receive projection 36. In certain preferred embodiments, a fastener 74 may be used to help secure projection 38 within recess 72. In the illustrated embodiment, fastener 74 is a hook and loop fastener with a first portion 76 secured to projection 38 and a second portion 78 secured to an interior surface of recess 72. It is to be appreciated that other types of fasteners will be suitable for securing projection 38 within recess 72 including, for example, snaps and snap rivets. Other suitable fasteners will become readily apparent to those skilled in the art, given the benefit of this disclosure. In light of the foregoing disclosure of the invention and description of the preferred embodiments, those skilled in this area of technology will readily understand that various modifications and adaptations can be made without departing from the scope and spirit of the invention. All such modifications and adaptations are intended to be covered by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper is often formed of leather, synthetic materials, or a combination thereof and comfortably secures the footwear to the foot, while providing ventilation and protection from the elements. The sole structure generally incorporates multiple layers that are conventionally referred to as an insole, a midsole, and an outsole. The insole is a thin cushioning member located within the upper and adjacent the sole of the foot to enhance footwear comfort. The midsole, which is traditionally attached to the upper along the entire length of the upper, forms the middle layer of the sole structure and serves a variety of purposes that include controlling potentially harmful foot motions, such as over pronation, attenuating ground reaction forces, and absorbing energy. In order to achieve these purposes, the midsole may have a variety of configurations, as discussed in greater detail below. The outsole forms the ground-contacting element of footwear and is usually fashioned from a durable, wear resistant material that includes texturing to improve traction. A heel counter is often provided at the rear of the footwear, and is contoured to wrap around the user's heel and along the sides of the footwear. The heel counter provides stability and support for the user's heel. The upper wraps around the rear exterior surface of the heel counter and is secured thereto, with a seam typically being provided in the upper at the rear of the heel counter. It is an object of the present invention to provide an article of footwear with a heel pad that reduces or overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain preferred embodiments. | <SOH> SUMMARY <EOH>The principles of the invention may be used to advantage to provide an article of footwear with a removable heel pad that provides additional cushioning and support for a user's heel and ankle. In accordance with a preferred embodiment, an article of footwear includes a sole assembly, an upper secured to the sole assembly, a heel counter secured to the upper, and a heel pad removably attached to an inner surface of the heel counter. In accordance with another preferred embodiment, an article of footwear includes a sole assembly and an upper secured to the sole assembly. A heel counter is secured to the upper and has a plurality of recesses. A heel pad having a plurality of projections extends outwardly from an exterior surface thereof, with each projection being received by a corresponding recess to removably attach the heel pad to the heel counter. In accordance with a further preferred embodiment, an article of footwear includes a sole assembly having an outsole, a midsole and an insole. An upper is secured to the midsole, and a heel counter is secured to the upper. The heel counter has a first recess on a medial side thereof and a second recess on a lateral side thereof. A heel pad has a first projection on a medial side thereof and a second projection on a lateral side thereof. The first recess receives the first projection and the second recess receives the second projection. A first fastener secures the first projection within the first recess, and a second fastener secures the second projection within the second recess. A collar is secured to an interior surface of the upper, with a lower surface of the collar being adjacent an upper edge of the heel pad. In accordance with yet another preferred embodiment, an article of footwear includes a sole assembly having an outsole, a midsole and an insole. An upper is secured to the midsole, and a heel counter is secured to the upper. The heel counter has a first aperture on a medial side thereof and a second aperture on a lateral side thereof. A heel pad has a first projection on a medial side thereof and a second projection on a lateral side thereof. The first aperture receives the first projection and the second aperture receives the second projection. A collar is secured to an interior surface of the upper, with a lower surface of the collar being adjacent an upper edge of the heel pad. Substantial advantage is achieved by providing an article of footwear with a removable heel pad. In particular, preferred embodiments of the present invention help improve the fit about a user's heel, helping to maintain the heel in proper position, reduce relative movement of the user's heel, and improve comfort. Additionally, preferred embodiments of the present invention allow different heel pads to be installed in the article of footwear, allowing customization and/or optimization of the footwear. These and additional features and advantages of the invention disclosed here will be further understood from the following detailed disclosure of certain preferred embodiments. | 20040715 | 20070130 | 20060119 | 94490.0 | A43B2308 | 0 | BAYS, MARIE D | ARTICLE FOOTWEAR WITH REMOVABLE HEEL PAD | UNDISCOUNTED | 0 | ACCEPTED | A43B | 2,004 |
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10,891,874 | ACCEPTED | Welding wire package with lifting strap | A package for containing a coil of wire having an outer cylindrical surface extending about a coil axis, a top and an oppositely facing bottom has a base for supporting the bottom of a wire coil when the wire coil is in the package. At least one side wall extends upwardly from the base about an outer cylindrical surface of the wire coil and has an upper edge defining a top opening in the package for removing the wire. The packaging further includes a hold-down bar between the bottom of the wire coil and the base which is transverse to the axis of the wire coil, and a lifting strap having a first end, a second end and a base portion between the first and second ends and between the bottom of the wire and the base. The base portion has an opening and the hold-down bar extends through the opening. | 1. A package for containing a coil of wire having a coil axis, a top and a bottom; said package comprising: a base for supporting a wire coil in said package with the axis of the coil extending upwardly of the base; wall means extending upwardly from said base and having an upper edge defining a top opening for said package, a bar at said base transverse to said wall means; and a lifting strap having a first end, a second end and a base portion between said first and second ends, said base portion having an opening, and said bar extending through said opening. 2. The package of claim 1, wherein a portion of said hold-down bar is between the bottom of the wire coil and said base. 3. The package of claim 1, wherein said base includes a pair of inner flaps and a pair of outer flaps, said inner flaps having flap ends which face one another and which are spaced from one another forming a flap recess, said bar being at least partially in said flap recess. 4. The package of claim 1, wherein said wall means comprises four side walls including a first and a second side wall having a first and a second upper edge, respectively, said package further including a pair of top flaps extending from said first and second upper edges, a first opening near said first upper edge and a second opening near said second upper edge, and said first and second ends of said lifting strap respectively passing through said first and second openings. 5. The package of claim 4, wherein said pair of top flaps includes a first top flap and a second top flap, said first opening being between said first flap and said first side wall and said second opening being between said second flap and said second side wall. 6. The package of claim 4, further including an inner liner adjacent said four side walls, said lifting strap extending between said liner and said first and second side walls. 7. The package of claim 1, wherein said bar is a straight bar 8. The package of claim 1, further including an inner liner adjacent said wall means, and said lifting strap extending between said liner and said wall means. 9. The package of claim 8, further including a hold-down mechanism, and said bar being part of said hold-down mechanism. 10. The package of claim 1, wherein said base portion of said lifting strap has strap edges and oppositely facing strap faces extending between said strap edges, said opening being in said strap between said faces and side edges. 11. The package of claim 10, wherein said base includes a pair of inner flaps and a pair of outer flaps, said inner flaps having flap ends which face one another and which are spaced from one another forming a flap recess, said bar being at least partially in said flap recess. 12. The package of claim 10, wherein said wall means comprises four side walls including a first and a second side wall having a first and a second upper edge, respectively, said package further including a pair of top flaps extending from said first and second upper edges, and said first and second ends of said lifting strap respectively passing through said first and second openings. 13. The package of claim 12, wherein said pair of top flaps includes a first top flap and a second top flap, said first opening being between said first flap and said first side wall and said second opening being between said second flap and said second side wall. 14. The package of claim 12, further including an inner liner adjacent said four side walls, said lifting strap extending between said liner and said first and second side walls. 15. The package of claim 1, further including a hold-down mechanism, and said bar being part of said hold-down mechanism. 16. The package of claim 1, wherein said base portion of said lifting strap has strap edges and oppositely facing strap faces extending between said strap edges, said lifting strap further including a secondary strap joined to said base portion, said opening being a spacing between said based portion and said secondary strap. 17. The package of claim 16, wherein said base includes a pair of inner flaps and a pair of outer flaps, said inner flaps having flap ends which face one another and which are spaced from one another forming a flap recess, said bar being at least partially in said flap recess. 18. The package of claim 16, wherein said wall means comprises four side walls including a first and a second side wall having a first and a second upper edge, respectively, said package further including a pair of top flaps extending from said first and second upper edges, a first opening near said first upper edge and a second opening near said second upper edge, and said first and second ends of said lifting strap respectively passing through said first and second openings. 19. The package of claim 18, wherein said pair of top flaps includes a first top flap and a second top flap, said first opening being between said first flap and said first side wall and said second opening being between said second flap and said second side wall. 20. The package of claim 18, further including an inner liner adjacent said four side walls, said lifting strap extending between said liner and said first and second side walls. 21. The package of claim 16, wherein said secondary strap is sewn to said base portion. 22. The package of claim 16, wherein said secondary strap has a cross-sectional configuration similar to a cross-sectional configuration of said lifting strap. 23. The package of claim 16, wherein said bar is a straight elongated bar. 24. The package of claim 1, further including a hold-down mechanism, and said bar being separate from said hold-down mechanism. 25. The package of claim 1, wherein said base portion of said lifting strap has strap edges, a bottom face and a top face, said top and bottom faces extending between said strap edges, said lifting strap further including a secondary strap joined to said bottom face of said base portion, said opening being a spacing between said bottom face of said based portion and said secondary strap, and said bar passing below said base portion. 26. The package of claim 1, wherein said bar is an elongate rod. 27. The package of claim 1, wherein said bar is metal. 28. The package of claim 1, wherein said bar is spaced from said wall means. 29. The package of claim 1, wherein said bar is secured in said package by the engagement between said bar, said base and the bottom of a wire coil in the package. 30. The package of claim 1, wherein said lifting strap has a length such that said first and second ends can extend vertically above said top opening. 31. The package of claim 1, wherein said wall means includes a cylindrical side wall. 32. The package of claim 31, wherein said base portion of said lifting strap has strap edges and oppositely facing strap faces extending between said strap edges, said opening being in said strap between said faces and said side edges. 33. The package of claim 31, wherein said base portion of said lifting strap has strap edges and oppositely facing strap faces extending between said strap edges, said lifting strap further including a secondary strap joined to said base portion, said opening being a spacing between said based portion and said secondary strap. 34. The package of claim 33, further including base inserts on said base of said package, said base inserts being spaced from one another thereby forming a recess, said bar being at least partially in said recess. 35. A package for containing a coil of wire having a coil axis, a top and a bottom; said package comprising: a base for supporting a wire coil in said package; wall means extending upwardly from said base, said wall means having an upper edge defining a top opening for said package; a bar at said base transverse to said wall means; and a lifting strap having a first end and a second end and a bar connector between said first and second ends, said strap being selectively connectable to said bar at said connector. 36. The package of claim 35, wherein said base includes a pair of inner flaps and a pair of outer flaps, said inner flaps having flap ends which face one another and which are spaced from one another forming a flap recess, said bar being at least partially in said flap recess. 37. The package of claim 35, wherein said lifting strap has strap edges and oppositely facing strap faces extending between said strap edges, said bar connector being an opening in said strap between said faces and said side edges. 38. The package of claim 35, wherein said lifting strap has strap edges and oppositely facing strap faces extending between said strap edges, said lifting strap further including a secondary strap joined to said lifting strap, said bar connector being an opening provided by a spacing between said lifting strap and said secondary strap. 39. The package of claim 38, wherein said secondary strap is below said lifting strap. 40. A package containing a coil of wire having a coil axis, a top and a bottom; said package comprising: a base for supporting a wire coil in said package with the coil axis extending upwardly of the base; wall means extending upwardly from said base and having an upper edge defining a top opening in said package for removing the wire; a hold-down mechanism; and a lifting strap having a first end, a second end and a base portion between said first and second ends, at least a portion of said base portion being between said base and the bottom of a wire coil and said base, said portion being selectively interengageable with said hold-down mechanism. | The present invention relates to welding wire packaging and more particularly to a welding wire package with an improved lifting strap configuration that cannot be easily removed until the welding wire is consumed. INCORPORATION BY REFERENCE Welding wire used in high production operations, such as robotic welding stations, is provided in a package generally having over 200 pounds of wire. The package is often a drum where a large volume of welding wire is looped in the drum around a central core or a central clearance bore. During transportation a hold down mechanism can be used to prevent the wire coil from shifting. To control the transportation and payout of the wire, it is standard practice to provide an upper retainer ring which can be utilized as a part of the hold down mechanism to prevent wire shifting. One such package is shown in Cooper U.S. Pat. No. 5,819,934 which is incorporated by reference herein as background material showing the same. Another such packaging is shown in Kawasaki U.S. Pat. No. 4,869,367 which is also incorporated by reference herein for showing welding wire packages utilizing hold down mechanisms. Cipriani U.S. Pat. No. 6,481,575 shows a welding wire package which utilizes a packing skid and is also incorporated by reference for showing the same. Jenkins U.S. Pat. No. 5,374,005 shows a wire package which utilizes handles and is also incorporated by reference for showing the same. BACKGROUND OF INVENTION In the welding industry, a tremendous number of robotic welding stations are each operable to draw welding wire from a package to provide a continuous supply of wire to perform successive welding operations. The advent of this mass use of electric welding wire has created a need for large packages for containing and dispensing large quantities of welding wire. A common package is a drum where looped or coiled welding wire is deposited in the drum as a wire stack, or body, of wire having a top surface with an outer cylindrical surface against the drum and an inner cylindrical surface defining a central bore. The central bore is often occupied by a cardboard cylindrical core as shown in Cooper U.S. Pat. No. 5,819,934. It is common practice for the drum to have an upper retainer ring that is used in transportation to stabilize the body of welding wire as it settles. This ring, as is shown in Cooper, remains on the top of the welding wire to push downward by its weight so the wire can be pulled from the body of wire between the core and the ring. In addition, a hold-down mechanism can be utilized to increase the downward force. As can be appreciated, large welding wire packages are heavy and require the use of lifts and other material transport devices to move the packages. As can also be appreciated, the wire packages may be moved several times before the wire is consumed. This can include several moves between the wire manufacturer and the end user and even several moves once the package reaches the end user. Therefore, it is advantageous to include a mechanism on the packaging to facilitate the use of lifting equipment to move the packaging. Some prior art packages include handles on their outer surfaces to help grasp the container. However, handles provide little benefit for larger wire packages. Other prior art welding wire packages include a built in packing skid or pallet to allow a fork lift to move the wire packaging. As can be appreciated, the packing skid which is heavy and bulky, and often expensive, must be disposed of once the welding wire is consumed. In view of the high volumes of welding wire used during many welding operations, especially robotic welding operations, there is a need for a wire package that is easily and economically disposable. In order to overcome the shortcomings of packing skids, others have utilized lifting straps to lift the heavy wire packages. These lifting straps have loops on either end and the straps extend into the packaging and wrap around the base of the wire coil. The loops are utilized to attach the packaging to a lifting device. However, if only one loop is pulled, the strap can be pulled from the packaging. As can be appreciated, once the strap has been pulled from the packaging, it is difficult, if not impossible, to utilize the strap to lift the welding wire package. Further, if the strap is securely affixed to the packaging, such as by staples, it is difficult to separate the strap from the packaging after the wire is consumed. As can be appreciated, in order to recycle the packing materials, it is advantageous to be able to easily separate unlike materials, such as separating paper products of the package from the materials used to make the strap. STATEMENT OF INVENTION In accordance with the present invention, a welding wire package is provided which includes a lifting strap that cannot be pulled from the packaging but which is also easily separable from the packaging after the welding wire is consumed. In this respect, a package according to the present invention includes a lifting strap which interengages with the hold-down mechanism of the wire package to prevent removal of the strap until the welding wire is consumed. An object of the present invention is the provision of a welding wire package which includes a lifting strap that cannot be inadvertently removed from the package until the welding wire has been consumed. A further object of the present invention is the provision of welding wire package which includes a lifting strap that prevents removal of the strap before the welding wire has been consumed. Still a further object of the present invention is the provision of a welding wire package which includes a lifting strap that can be easily separated from the remaining package components after the welding wire has been consumed. Another object of the present invention is the provision of a welding wire package which includes a lifting strap that can be used to transport the package. Yet another object of the present invention is the provision of a welding wire package which includes a lifting strap that is economical to produce, easy to use and either reuse or discard after use. BRIEF DESCRIPTION OF DRAWINGS The foregoing objects, and others, will in part be obvious and in part pointed out more fully hereinafter in conjunction with a written description of preferred embodiments of the present invention illustrated in the accompanying drawings in which: FIG. 1 is a perspective view of a welding wire package according to the present invention with a lifting strap in a non-lifting condition; FIG. 2 is a cross-sectional elevation view taken along line 2-2 of FIG. 1; FIG. 3 is a cross-sectional elevation view as is shown in FIG. 2 with the lifting strap in a lifting condition; FIG. 4 is an enlarged perspective sectional view of the base area of the package shown in FIG. 1; FIG. 5 is an enlarged perspective sectional view of the base area of another embodiment of the present invention; FIG. 6 is a perspective view of yet another embodiment of a welding wire package according to the present invention with a lifting strap in the lifting condition; and, FIG. 7 is a cross-sectional elevation view taken along line 7-7 of FIG. 6. DESCRIPTION OF PREFERRED EMBODIMENTS Referring now in greater detail to the drawing wherein the showings are for the purpose of illustrating preferred embodiments of the invention only, and not for the purpose of limiting the invention, FIGS. 14 illustrate a welding wire drum type package 10 wherein a wire W is stored in and paid out of the package which includes a bottom 12, a top 14, and a cylindrical side wall 15 having an inner surface 16. Package 10 can further include a cylindrical cardboard core (not shown) concentric with surface 16. Package 10 further includes a hold-down mechanism 20 which helps maintain a coil 30 of wire W and prevents coil 30 from shifting during transportation. As is know, package 10 is loaded with wire W at the wire manufacturing facility and the wire is looped into the package to define a body of welding wire, namely, wire coil 30 having a top surface 40, an outer cylindrical surface 42 against surface 16 and an inner cylindrical surface 44. In this manner, a central vertically extending bore 46 is formed which is concentric with surface 16. Again, in some instances, an inner core (not shown) can be used. The coil further includes a bottom surface 48 which can rest against package bottom 12 which will be discussed in greater detail below. The wire is looped in a manner such that it has a cast to facilitate payout with a minimum of tangles. This produces an upward springing effect which must be controlled during both the transport of packaging 10 and during the unwinding of the welding wire. During the transport of the package the upward springing, and generally the prevention of wire shifting in the coil, is managed by hold-down mechanism 20. Hold-down mechanism 20 includes a hold-down bar 50, a force producing member 52 and a top bar 54. As is stated above, the hold-down mechanism prevents the shifting and/or upward springing of the wire in the wire coil during transport. This is accomplished by producing a downward force on top surface 40 of coil 30. More particularly, hold down bar 50 is maintained relative to bottom 12 of the package. Bar 50 can be any known hold-down bar including, but not limited to, a straight elongated bar, a curved bar (not shown) or a hook (not shown). Further, based on all intended uses of bar 50, the bar is made from a suitable material such as, but not limited to, metal. Depending on the type of bar utilized, the bar is secured relative to the bottom of the package. In the case of a straight hold down bar, the bar can be positioned between coil bottom 48 and bottom 12 of package 10. The weight of coil 30 prevents upward movement of the bar. However, hold down bar 50 can also be fastened to wall 15 and/or bottom 12. Force member 52 is attached between hold-down bar 50 and top bar 54 such that member 52 produces a downward force in top bar 54. Member 52 can be any know force producing member including, but not limited to, an elastic band or a spring, as shown. Hold-down mechanism 20 can further include a ring 56 on top surface 40 of the coil to produce an even downward force on the coil. Ring 56 can be a retainer ring which is also used to prevent tangles in wire W as the wire is unwound from wire coil 30. As is known in the art, package 10 can further include a ring protection member (not shown) which extends between top bar 54 and ring 56. In this respect, if ring 56 is a retainer ring, it is typically configured for maximum functionality for the controlling of the unwinding of the wire and is not optimally designed for the transport of the package. As is shown, ring 56 has a top surface 60 and a bottom surface 62 wherein bottom surface 62 engages coil top 40. Top bar 54 engages top ring surface 60 to produce the downward force on ring 56. Ring 56 further includes an outer periphery 64 having a diameter less than that of inner surface 16 of wall 15 and an inner periphery 66. As is shown, outer periphery 64 can be spaced slightly inward of surface 16. Further, ring 56 can be any known ring in the art and/or can be a ring design for transporting only. Package 10 further includes a lift strap 70 having a first end 72 and a second end 74. First and seconds ends 72 and 74 include loops or rings 76 and 78, respectively. Loops 76 and 78 can be of any configuration and constructed of any suitable material including, but not limited to, metal, and can be loops created integrally by the material of strap 70. Loops 76 and 78 are used to attach strap 70 to a lifting device 90 that can also be any known device in the art. Strap 70 has a middle section or bottom 80 between ends 72 and 74 that is positioned between bottom 12 and coil bottom 48. As will be appreciated, the majority of the weight of package 10 is from coil 30. Therefore, by extending below the coil, the strap can support the weight of the package without being attached to the outer packaging. Strap 70 is provided with a strap securing hole 82 in bottom section 80 for securing the strap to hold-down bar 50. In this respect, hold-down bar 50 extends through strap hole 82 such that strap 70 cannot be removed from package 10 without dislodging bar 50. While it is preferred that an existing structure, such as mechanism 20, be used to secure strap 70, bar 50 can be an independent component with its primary function being to secure strap 70. In one embodiment (FIG. 4), strap hole 82 is produced by a strap section 84 attached to strap 70 at strap bottom 80 by any known means. This can include, but is not limited to, sewing strap section 84 to strap 70. By including section 84 which extends generally parallel to bottom 80, hole 82 is substantially parallel to the strap faces of strap 70. As a result, bar 50 can extend through hole 82 without twisting or distorting the strap. In another embodiment, package 10 can further include inserts or flaps 92 and 94 that are smaller than bottom 12 such that they produce a flap recess 96. Flap recess 96 is large enough to a least partially receive bar 50. By having recess 96, bar 50 is more difficult to dislodge and has less bending affect on coil 30 at the points in which bar 50 extends under the coil. In yet another embodiment (FIG. 5), strap section 80 has a strap securing hole 100 integral therewith between strap edges 102 and 104. Hole 100 can be cut into strap bottom 80 or can be sewn into the strap section or can be produced in any known manner in the art. As will be appreciated, while only two arrangements for providing strap holes are shown, other arrangements for providing strap holes, and/or other methods of securing strap 70 to bar 50, and/or another component of mechanism 20 can be utilized without detracting from the invention. Strap 70 further includes upward extending portions 110 and 112 which extend upwardly from either side of bottom 80. In this embodiment, portions 110 and 112 extend between outer coil surface 42 and inner carton surface 16. However, while not shown, package 10 can further include a liner and/or a vapor barrier extending around coil 30 and can include other packaging material(s) known in the art. In order to better stabilize the lifting of package 10, the package further includes diametrically opposite strap openings 114 and 116 in side wall 15 near top 14. The strap openings are shaped to allow strap 70 to pass through side wall 15. Outer sections 120 and 122 of strap 70 extend from openings 114 and 116, respectively, to strap ends 72 and 74. As can be seen best in FIG. 3, by passing strap 70 through strap openings 114 and 116, the position of strap bottom 80, and strap sections 110 and 112, are substantially maintained regardless of the direction of the lifting forces produced by lifting device 90. In addition, lifting stability is increased by at least partially controlling the lifting at a point at or near top 14 of package 10. In the following discussions concerning yet further embodiments of the present invention, the components of the wire package which remain the same as those discussed above are identified by the same reference numbers. With reference to FIGS. 6 and 7, welding wire package 200 is shown. As will be appreciated from these figures, welding wire strap 70 can be used with a wide range of welding wire packages known in the art including square box packages such as welding wire package 200. In addition, while not shown, package 200 can include a hold-down mechanism such as hold-down mechanism 20. In this respect, if a hold down mechanism is not desired or a different style is used, bar 50 in any embodiment can be used only for strap 70 such that it does not have a secondary function. As is shown, package 200 includes bar 50 positioned below coil bottom 48. Essentially, strap 70 is as discussed above and, therefore, will not be discussed in detail with respect to package 200. However, due to the square design of this packaging, package 200 can include rectangular inner bottom flaps 210 and 212 and outer bottom flaps 214 and 216. In order to produce a flap recess 220 for at least partially receiving bar 50, inner flaps 210 and 212 can be shortened. As stated above, by including flap recess 220, bar 50 has less of a distorting affect on coil 30. Further, recess 220 makes it more difficult to dislodge bar 50 and, therefore, strap is better secured to package 200 without the need to fasten the strap to the package. As with package 10, strap 70 can utilize a wide range of arrangements for providing holes to allow bar 50 to pass through strap 70 and maintain the strap relative to the bar until the wire is consumed. Package 200 includes side walls 230 and 232 which extend upwardly from inner flaps 210 and 212, respectively, and side walls 234 and 236 which extend upwardly from outer flaps 214 and 216. However, it will be appreciated, that walls 230 and 232 can extend from the outer bottom flaps and walls 234 and 236 can extend from the inner bottom flaps. Side wall 230 extends to a top edge 240, Side wall 232 extends to a top edge 242, Side wall 234 extends to a top edge 244 and Side wall 236 extends to a top edge 246. Package 200 further includes inner top flaps 250 and 252 extending respectively from side walls 230 and 232, and outer flaps 254 and 256 extending respectively from side walls 234 and 236. Again, while not shown, the inner and outer top flaps can be attached to any of the side walls of package 200. Package 200 further includes openings 260 and 262 at or near top edges 240 and 242, respectively. As discussed above with package 10, openings 260 and 262 are large enough to allow strap 70 to pass from the inside of package 200 to the outside. Similar to package 10, this configuration increases the stability of package 200 when being lifted by lifting device 90. As will be appreciated, openings similar to openings 260 and 262 can also be provided at or near top edges 244 and 246 of sides 234 and 236, thus providing selectively for the position of the coil and strap in the box. While only a few package configurations are shown, the invention of this application can be used with a wide range of welding wire packages and package accessories known in the art. The accessories include, but are not limited to, a package liner 270 between the side wall(s) and outer surface 42 of coil and, while not shown, vapor barriers, corner supports for the other hold-down mechanisms, and a wide range of retainer rings. While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principals of the invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation and that it is intended to include other embodiments and all modifications of the preferred embodiments insofar as they come within the scope of the appended claims or the equivalents thereof. | <SOH> BACKGROUND OF INVENTION <EOH>In the welding industry, a tremendous number of robotic welding stations are each operable to draw welding wire from a package to provide a continuous supply of wire to perform successive welding operations. The advent of this mass use of electric welding wire has created a need for large packages for containing and dispensing large quantities of welding wire. A common package is a drum where looped or coiled welding wire is deposited in the drum as a wire stack, or body, of wire having a top surface with an outer cylindrical surface against the drum and an inner cylindrical surface defining a central bore. The central bore is often occupied by a cardboard cylindrical core as shown in Cooper U.S. Pat. No. 5,819,934. It is common practice for the drum to have an upper retainer ring that is used in transportation to stabilize the body of welding wire as it settles. This ring, as is shown in Cooper, remains on the top of the welding wire to push downward by its weight so the wire can be pulled from the body of wire between the core and the ring. In addition, a hold-down mechanism can be utilized to increase the downward force. As can be appreciated, large welding wire packages are heavy and require the use of lifts and other material transport devices to move the packages. As can also be appreciated, the wire packages may be moved several times before the wire is consumed. This can include several moves between the wire manufacturer and the end user and even several moves once the package reaches the end user. Therefore, it is advantageous to include a mechanism on the packaging to facilitate the use of lifting equipment to move the packaging. Some prior art packages include handles on their outer surfaces to help grasp the container. However, handles provide little benefit for larger wire packages. Other prior art welding wire packages include a built in packing skid or pallet to allow a fork lift to move the wire packaging. As can be appreciated, the packing skid which is heavy and bulky, and often expensive, must be disposed of once the welding wire is consumed. In view of the high volumes of welding wire used during many welding operations, especially robotic welding operations, there is a need for a wire package that is easily and economically disposable. In order to overcome the shortcomings of packing skids, others have utilized lifting straps to lift the heavy wire packages. These lifting straps have loops on either end and the straps extend into the packaging and wrap around the base of the wire coil. The loops are utilized to attach the packaging to a lifting device. However, if only one loop is pulled, the strap can be pulled from the packaging. As can be appreciated, once the strap has been pulled from the packaging, it is difficult, if not impossible, to utilize the strap to lift the welding wire package. Further, if the strap is securely affixed to the packaging, such as by staples, it is difficult to separate the strap from the packaging after the wire is consumed. As can be appreciated, in order to recycle the packing materials, it is advantageous to be able to easily separate unlike materials, such as separating paper products of the package from the materials used to make the strap. | <SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>The foregoing objects, and others, will in part be obvious and in part pointed out more fully hereinafter in conjunction with a written description of preferred embodiments of the present invention illustrated in the accompanying drawings in which: FIG. 1 is a perspective view of a welding wire package according to the present invention with a lifting strap in a non-lifting condition; FIG. 2 is a cross-sectional elevation view taken along line 2 - 2 of FIG. 1 ; FIG. 3 is a cross-sectional elevation view as is shown in FIG. 2 with the lifting strap in a lifting condition; FIG. 4 is an enlarged perspective sectional view of the base area of the package shown in FIG. 1 ; FIG. 5 is an enlarged perspective sectional view of the base area of another embodiment of the present invention; FIG. 6 is a perspective view of yet another embodiment of a welding wire package according to the present invention with a lifting strap in the lifting condition; and, FIG. 7 is a cross-sectional elevation view taken along line 7 - 7 of FIG. 6 . detailed-description description="Detailed Description" end="lead"? | 20040715 | 20070529 | 20060119 | 94941.0 | B65D8500 | 1 | REYNOLDS, STEVEN ALAN | WELDING WIRE PACKAGE WITH LIFTING STRAP | UNDISCOUNTED | 0 | ACCEPTED | B65D | 2,004 |
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10,891,962 | ACCEPTED | System and method for paying down debt using an equity loan revolving line of credit | A loan system program comprises a loan account having a loan principal on a purchased item, and a secondary account used to pay the amortized interest on the loan principal. A user deposits, such as through automatic deposit, user payments directly into the loan account, thus paying down the loan principal. The user then uses the secondary account for personal expenses that would otherwise be met by the deposited user payments. At the end of the month or grace period, the user pays off the monthly interest on the loan account with the secondary account. The lender than raises the loan balance of the loan account to cover the secondary account balance. At least a portion of the next user deposit to the loan account covers the raise loan balance, and another portion is used to pay down the loan principal. | 1. In a mortgage system in which a loan account is secured to a property, the loan account comprising principal and interest, a method of paying the loan principal, such that equity in the property is increased, the method comprising the acts of: receiving a first user payment into a loan account; applying at least a first portion of the first user payment to the loan principal; receiving a payment for at least amortized monthly interest on the loan account from a credit account, wherein the credit account comprises a credit limit and a grace period; incurring a further debt on the loan account to pay off the balance of the credit account, the further debt causing the amount owed on the loan account to increase; receiving a second user payment into the loan account; applying at least a first portion of the second user payment to the further debt incurred on the loan; and applying a second different portion of the second user payment to the loan principal. 2. The method as recited in claim 1, wherein any of the first and second users payment is an employment compensation, a social security payment, a trust fund payment, an individual retirement account payment, or a payment from a user savings account. 3. The method as recited in claim 2, further comprising applying at least a second portion of the first user payment into another account. 4. The method as recited in claim 2, wherein the entire first user payment is automatically deposited into the loan account, such that the loan principal is reduced by the amount of the automatically deposited first user payment. 5. The method as recited in claim 1, wherein the loan account is a revolving loan account, and wherein the credit account is a conventional credit card account. 6. The method as recited in claim 5, wherein the loan account comprises a fixed year arm, a fixed year balloon payment, a fixed-interest rate loan, or a variable-interest rate loan. 7. The method as recited in claim 1, wherein the lender of the loan account is different from a provider of the credit account. 8. The method as recited in claim 1, further comprising an act of using the credit account to pay a credit account service fee, such that a provider of the credit account receives the credit card service fee as a payment. 9. The method as recited in claim 1, further comprising an act of charging a loan service fee to the loan account, wherein a lender of the loan account receives the loan service fee as a payment. 10. The method as recited in claim 1, wherein the at least amortized monthly interest is not compounded with the loan principal. 11. The method as recited in claim 10, wherein the at least amortized monthly interest comprises interest that is amortized at a rate that is less than monthly, a rate that is less than weekly, or that is amortized daily. 12. The method as recited in claim 1, wherein loan account is a home equity loan account. 13. In a mortgage system in which a loan account is secured to a property, the loan account comprising principal and interest, a method of managing a loan program for a user, such that equity in the property is increased, the method comprising the acts of: providing a user with a revolving loan account, the loan account having a loan principal and a monthly loan interest; providing a secondary account having an access limit based at least on a monthly user budget, and the monthly loan interest; automatically paying the monthly loan interest with the secondary account; and automatically paying down the loan principal and the secondary account at least in part with one or more user payments, such that the principal is paid down each time at least one of the one or more user's payments are received. 14. The method as recited in claim 13, further comprising identifying a user income and budget, wherein the lender identifies the access limit based at least in part on the identified user income and the user budget. 15. The method as recited in claim 13, wherein the secondary account comprises one of a credit account, a checking account, an access limit on the loan account, or a third party provided account. 16. The method as recited in claim 13, further comprising amortizing the loan interest on the loan principal on a daily basis. 17. The method as recited in claim 13, wherein the one or more user payments are an employment compensation, a social security payment, a trust fund payment, an individual retirement account payment, or a payment from a user savings account. 18. The method as recited in claim 13, wherein at least a first portion of the at least one of the one or more user payments is automatically deposited into the loan account, and wherein at least a second portion of the at least one of the one or more user payments is deposited into another account. 19. The method as recited in claim 13, wherein the entire one or more user payments are automatically deposited into the loan account, such that the loan principal is reduced by the amount of the automatically deposited one or more user payments. 20. The method as recited in claim 13, wherein the loan account is a revolving loan account, and wherein the secondary account is one of a conventional credit card account, a checking account with an overdraft limit, a money market account, and an access limit attached to the loan account. 21. The method as recited in claim 20, wherein the loan account comprises a fixed year arm, a fixed year balloon payment, a fixed-interest rate loan, or a variable-interest rate loan. 22. The method as recited in claim 13, further comprising an act of automatically deducting a loan service fee from the loan account, wherein a lender of the loan account receives the loan service fee as a payment. 23. The method as recited in claim 13, further comprising an act of automatically deducting an account service fee from the secondary account, wherein a provider of the secondary account receives the account service fee as a payment. 24. A computer program product for use in a mortgage system in which a loan account is secured to a property, the loan account comprising principal and interest, the computer program product implementing a method of paying the loan principal, such that equity in the property is increased, the computer program product method comprising one or more computer-readable media having computer-executable instructions stored thereon that, when executed at a processor, cause the mortgage system to perform the following: receive a first user payment into a loan account, apply at least a first portion of the first user payment to the loan principal; receive a payment for at least amortized monthly interest on the loan account from a credit account, wherein the credit account comprises a credit limit and a grace period; incur a further debt on the loan account to pay off the balance of the credit account, the further debt causing the amount owed on the loan account to increase; receive a second user payment into the loan account; apply at least a first portion of the second user payment to the further debt incurred on the loan; and apply a second different portion of the second user payment to the loan principal. 25. The method as recited in claim 24, wherein the loan account is a revolving loan account, and wherein the credit account is a conventional credit card account. 26. The method as recited in claim 24, wherein the loan account comprises a fixed year arm, a fixed year balloon payment, a fixed-interest rate loan, or a variable-interest rate loan. | CROSS-REFERENCE TO RELATED APPLICATIONS The present invention claims the benefit of priority to U.S. Provisional Patent Application No. 60/491,423, filed on Jul. 30, 2003, entitled “SYSTEM AND METHOD FOR INCREASED EQUITY THROUGH CREDIT CARD REVOLVING LINE OF CREDIT”; and to U.S. Provisional Patent Application No. 60/581,115, filed on Jun. 17, 2004, entitled “SYSTEM AND METHOD FOR INCREASED EQUITY THROUGH CREDIT CARD REVOLVING LINE OF CREDIT” The entire contents of each of the foregoing patent applications are incorporated by reference. BACKGROUND OF THE INVENTION 1. The Field of the Invention This invention relates to systems, methods, and computer program products for debt reduction. 2. Background and Relevant Art Monetary debt, which and entails paying for an item at a later date, is a growing problem for many people. For example, a consumer can now finance any number of secured debts, such as homes, cars, property, expensive goods, as well as unsecured debts, such as items purchased through a credit card or line of credit, education loans, etc. In each case, paying for the item at a later date can add to the expense of the item, and therefore create an unanticipated financial burden on the user. In particular, most debts require that the consumer pay back the debt with a certain amount of interest that is amortized over time, making the items far more expensive in the long-run than when purchased initially. As shown in FIG. 1, for example, a user (100) may purchase an item (e.g., a home 105) for a principal amount of $100,000 (117) by asking a lender (110) to finance the item (105) at a certain interest rate (118), such as an interest rate of 5%, amortized over 30 years. Using a simple interest calculation, the monthly payment (120) of principal (117) and interest (118) on such a purchase would be approximately $540, with the total amount paid on the loan being approximately $194,000. After making the final payment in the 30 year period, the user will have paid almost double ($194,000) the amount of the initial purchase ($100,000). In some cases, the financed items will appreciate in value over time, such that the value of the item is still greater than the total amount paid in the end. This, however, is not the case for many other depreciating items, such as debts to purchase cars, clothing, food, etc., which lose value with use over time In particular, depreciating items are typically not worth the amount paid for them with interest, especially at the time the consumer makes the last payment on the debt. For example, a payment of $100 in clothing (e.g., one or two pairs of pants) could accrue approximately $20 in interest assuming conventional interest rates, and assuming conventional minimum monthly payments. Thus, the used clothing is usually worth far less than paid initially by the time the final payment has been made (roughly a year in this example). This problem becomes far worse when the consumer fails to make timely payments, and hence incurs additional fees and interest rate increases. Accordingly, it is ideal in many cases to purchase an item up front, rather than paying at a later date (i.e., financing the item). While this sort of monetary discipline can be exercised for many types of wanted items, there are some necessary items that cannot ordinarily be purchased by most consumers without incurring at least some debt. For example, most people do not make enough money, or have enough cash on hand, to purchase a home with without incurring at least some debt. Furthermore, many people cannot afford even to purchase a home with financing that allows the home to be paid off within a relatively short time to minimize their interest payments, such as a time period of 10-15 years. In particular, short term loans, such as 10-15 year home loans, typically require a high monthly payment. This can be particularly difficult for a user since mortgage payments are usually required in a single monthly payment, such that the user cannot spread the total monthly payment in two partial payments, consistent with the user's bi-weekly paychecks. Thus, it is fairly common for users to purchase a home with financing that allows the home to be paid off within approximately 30 years. While this provides the benefit of a relatively low monthly payment, the total interest paid on the home is extremely high, often twice the value of the home. Furthermore, this means the user is likely to hold a significant amount of debt on a home up until (or just after) the user is ready to retire, depending on when the user purchased the home. Accordingly, some programs have been developed to help ease the debt burdens some users may face with large loans. In particular, some programs, such as bi-weekly payment programs, offer a person to pay down a debt, such as a home debt, more quickly than possible under a 30-year loan, without significantly burdening the user's monthly budget. For example, assuming a monthly mortgage costs $1,000 for a user. A bi-weekly program might allow the user to pay $542 every two weeks, such that the user has overpaid by $84 each month. The program administrator saves the extra $84 until $1000 has been saved up, and then makes an extra payment into the loan at the end of the year. Making an extra payment such as this has been shown to reduce the total term of the loan from approximately 30 years to approximately 22 or 23 years, representing a significant interest savings for the user. Unfortunately, payoff periods of 20 or more years can still represent a significant burden to many users in terms of time and cost, particularly those users who delay purchasing a home until they are somewhat advanced in age. For example, users who purchase homes while in their forties will still be paying down the debt as they approach retirement. Furthermore bi-weekly programs are not typically cost-free. With reference to the prior example, the program administrator might require the user to pay $684 per check (rather than $584) to operate the program, such that the user pays an additional approximately $200 a month ($100 extra every two weeks) in service fees. As such, in some cases, a user may believe that the benefits of reducing the term of the debt from 30 years to 20 years is difficult to justify compared to the burden of paying extra service fees with the reapportioned loan amounts each month. For example, biweekly programs, with their service fees, may be too expensive for some users who struggle to pay even the standard monthly debt payment. Still further, bi-weekly programs generally require a person to make additional efforts with their loans, after having spent considerable effort negotiating, procuring, and signing the original home loan. Accordingly, an advantage in the art can be realized with systems, methods, and computer program products that help a user pay off large debts in a relatively short period of time, such as paying off a home debt in less than 10 years, without substantially burdening the user's monthly budget for other expenses. BRIEF SUMMARY OF THE INVENTION The present invention solves one or more of the foregoing problems in the prior art with systems, methods, and computer program products for helping a user pay off a large debt, such as a home debt, in less than 10-15 years, where the debt would otherwise be due in 20-30 years. In particular, implementations of the present invention allow a user to pay off a large home debt—either from the purchase of a home or from a refinance of an existing loan, including consumer debt—much quicker than otherwise possible, while allowing a user to maintain current monthly expenses. For example, in one implementation, a user obtains a large loan from a lender, using a revolving loan account. The lender (or third party provider) further provides the user with a credit card having a credit limit and a grace period, where the credit limit is sufficient to cover the user's monthly personal expenses, as well as cover the monthly interest on the revolving loan. The user then deposits each user payment, such as a user paycheck, or such amount as the borrower sees fit, into the revolving loan account, such that the principal on the loan is paid down with the frequency and amount that the user is paid (e.g., bi-weekly or more). The credit account is used to pay off the daily interest that is owed monthly on the revolving loan. Also at the end of the credit account billing period, and further at the end of the credit card grace period, the lender pays off the credit card balance using the revolving loan account, such that the lender momentarily raises the revolving loan account balance, albeit slightly. When the lender receives the next user paycheck, the lender applies the user's payments, such as the user's paycheck, against the increased loan principal. Additional features and advantages of exemplary implementations of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of such exemplary implementations. The features and advantages of such implementations may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 illustrates a prior art schematic diagram in which a user obtains financing to purchase a property; FIG. 2A illustrates a schematic diagram in which a user pays off a loan principal and loan interest using two or more accounts in accordance with an implementation of the present invention; FIG. 2B illustrates a table of example loan principal and interest values when implementing the concepts depicted in FIG. 2A; FIG. 3 illustrates a method for paying down a loan principal and loan interest in accordance with an implementation of the present invention; and FIG. 4 illustrates a method for providing a user with a loan program that can be used to automatically pay down a loan principal and loan interest in accordance with an implementation of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention extends to both methods and systems that help a user pay off a large debt, such as a home debt, in less than 10-15 years, where the debt would otherwise be due in 20-30 years. In particular, implementations of the present invention allow a user to pay off a large home debt—either from the purchase of a home or from a refinance of an existing loan, including consumer debt—much quicker than otherwise possible, while allowing a user to maintain current monthly expenses. For example, FIG. 2A illustrates an overview of a loan system in which a lender 220 provides a user 200 with one or more accounts, such as a loan account 210 and a credit account 230, which are used respectively to pay for a given item, and to help pay back the loan account 210. As used herein, a “user” will be understood as any entity, such as an individual, a couple, a small group of individuals, one or more agents, and one or more companies that obtains a loan account 210 from a lender. A “lender” will be understood as a person or entity, such as an agent, or automated software instructions, at the lending institution, that provides the loan account 210, and/or manages the two or more accounts. A “loan account” will be understood as any type of credit provided by a lender to a user, such as a fixed or variable rate credit that is compounded at any given schedule. Furthermore, the loan account 210 will be understood as any type of credit that can be used to purchase any type of item, such as a home, or any other real property that a given lending institution might ordinarily finance. In particular, frequent reference is made herein to home loan accounts, since such loan accounts are relatively expensive, and since loans such as those can take up to 20-30 years to repay. Nevertheless, one will appreciate that the principles described herein can be applied broadly to a wide variety of items (and corresponding loans). For example, the principles described herein apply to such loans as conventional variable or fixed-interest rate loans, fixed-year (e.g., 1, 2, 3, 4, or 5-year) arms, fixed-year (e.g., 5-year) balloons, and so forth. Generally speaking, a loan account 210 described herein will also be understood primarily as an account having a measure of credit limit flexibility, such as a revolving loan, a home equity line of credit, or similar such account. In particular, a flexible credit limit type of loan account 210 provides a lender 220 with the ability to increase or decrease the amount of credit available in the loan account, as appropriate. For example, a home equity line of credit has a principal balance that can decrease with payment, or can increase with one or more user purchases (e.g., checks written on the line of credit account) that extend the current principal balance within a predetermined limit. The flexibility afforded by these types of accounts can also provide the user with a number of payment options, as understood from the following description. Continuing, FIG. 2A illustrates that a loan account 210 can also be described in terms of “principal” 217 and “interest” 218. Generally, “principal” 217 refers to the initial amount of the loan account 210 balance, while “interest” 218 refers generally to the monthly interest on the loan account 210 balance. In a simple example, a revolving loan account to pay for $100,000 of a home will carry a principal balance of $100,000. The amortized monthly “interest” (e.g., from daily amortization or some other period of amortization), however, is a percentage value of the principal loan balance measured over some period of time, such as a number of months or days in a 30-year period (i.e., 360 months, or roughly 131,500 days). For example, a lender 220 can provide a user with a $100,000 conventional loan, using a conventional 5% interest rate, amortized monthly over 30 years. Using a simple interest calculator, this would result in a monthly payment of $540, which includes some combination of principal 217 and interest 218. The lender 220 can calculate the interest any number of ways, such as by figuring a monthly portion of the annual interest owed (e.g., 5% divided by 12 months) on the loan account 210 balance at the end of a given month. Alternatively, the lender 220 can perform a similar interest calculation on an average daily loan account 210 balance at the end of the given month. With either calculation, the user 200 pays less interest 218 over time as the user pays down the loan principal 217. The lender 220 can also provide the loan by amortizing the interest 218 daily. In one implementation, for example, a lender 220 can take the conventional interest rate of 5%, and divide it by 360 days (commonly used) or 365 days to get 0.014%. The lender 220 can then compound the interest for each day into the loan account 210 balance, such that the lender 220 raises the loan account 210 balance from $100,000 to $100,014. The next day, the lender 220 factors the interest on the new balance ($100,014), such that overall loan account 210 balance is raised to $100,028, and so on. In another implementation, the lender 220 can simply add the interest for each daily balance into a separate interest account without compounding each day's interest with the principal. With reference to the foregoing examples and numbers, if the loan account 210 balance remains at $100,000 for the month, the lender 220 may simply add approximately $14 each day into a separate interest account. In this case, the loan account 210 balance would remain at $100,000, while the interest increases from $14 one day, to approximately $28 the next day, and so on. As with monthly amortization, the user 200 pays less interest 218 over time as the user pays down the loan principal 217. One will appreciate, therefore, that the methods for amortizing interest on a given loan can have a significant impact on the loan account 210 balance. In particular, accounts that are amortized monthly will not accrue interest as quickly as those that are amortized daily. On the other hand, daily amortization usually means that the lender 220 can receive more paid interest, and hence that the loan will cost more to the user 200. As such, monthly amortization is generally more favorable to the user 200, while daily amortization is generally more favorable to the lender 220. Even still, the user maintains some advantages with daily amortization. In particular, the user can usually make payments on the loan account 210 more than once a month, in contrast to most monthly-amortized loan accounts. This can enable the user to make significant adjustments to the loan account balance, upon which the lender 220 calculates the daily interest. Accordingly, FIG. 2A illustrates an implementation of the present invention in which the lender 220 takes advantage of these concepts by providing the user 200 with a revolving loan account 210. The loan can be for any fixed or variable term length, and for any value on the property, including up to 100% of the property value (or more, if appropriate). Furthermore, the lender 220 sets up the loan account 210 such that it is amortized daily. In particular, the lender 220 calculates the daily-amortized interest 218 separately, without compounding the interest 218 with the principal 217. The user 200 then pays the monthly interest 218, as well as all (or a predefined amount) of the user's personal expenses with a credit account 230 that has a certain credit limit (or access limit), and a grace period. As such, the credit limit is at least sufficient to cover the monthly loan interest 218, and to cover the user 200's monthly budget 205. Using a credit account 230 in this manner can provide the lender 220 and user 200 with a number of advantages. For example, and as will be understood in the following description, the lender 220 can set a certain credit limit that ensures that the user 200 applies a consistent, maximum amount of user payments to the loan account 210 principal 217. In addition, since many credit accounts provide users with rewards, the user can redeem rewards from the credit account 230 for free airplane tickets, free hotel stays, and so forth. That is, the more the user pays with the credit account 230, the more the user is likely to benefit. The lender 220 can also take advantage of these concepts by requiring the user 200 to deposit all (or some predetermined portion) of the user's payments into the loan account 210, each time the user is paid. This can be done through manual or automatic electronic deposit, although electronic deposit may be more efficient in some situations. For the purposes of this specification and claims, “payments”, or “pay” refers to any type of money or compensation that can be received by the user and/or applied to the loan account 210 for any reason. This can include receiving regular or irregular schedules of employment compensation, retirement account payments, social security payments, insurance account withdrawals, monetary transfers from a secondary account (e.g., from a user's savings account to the loan account), and so forth. FIG. 2B illustrates a sequential over view of blocks or steps in a method for implementing the system depicted in FIG. 2A, wherein the user 200 deposits the same amount of user payments into the loan account 210 on a bi-weekly basis for two months. As shown, the user 200 applies a first user payment 240 to the loan account 210, which causes the loan balance of $100,000 to drop, in step 243, to a balance of $98,000. Since the user applied the entire fund 240 to the loan principal 217, the user 200 incrementally spends the credit account 230 balance (not to exceed a balance of $460). Step 247 illustrates the credit account 230 balance on three selected days, as the user accommodate monthly personal expenses with the credit account 230. As shown in step 245, since the credit account 230 has not yet closed (i.e., not the end of the month), the lender's 220 funds to apply to the credit account 230 are $0. When the user applies a next user payment 250, step 253 shows that the account balance principal drops $98,000 to $96,000. Furthermore, as the end of the month approaches, the user 200 continues to charge, step 247, expenses to the credit account 230, in accordance with the user's monthly budget 205, such that the balance rises to $460. Either by the lender's 220 or the user's 200 direction, the credit account 230 is then used to pay off the monthly interest on the loan account 210. As shown in step 257, adding a monthly interest payment of $540 to the credit account balance of $460 causes the credit account 230 balance to rise to a total of $1,000. In at least one implementation, this occurs at (or just prior to) the end of the credit account 230 grace period. Also at the end of, or just prior to, the expiration of the credit account 230 grace period, the lender 220 increases the loan account 210 balance to pay off the credit account 230 in full, as shown in step 255. As shown in step 253, this causes the loan account 210 principal balance to rise from $96,000 to $97,000. Since the loan account 210 increase occurs at the end of the credit account 230 grace period (i.e., end of the month), the rise is only momentary since the user will deposit the next bi-weekly funds soon (i.e., beginning of the next month, step 260). In particular, the proximity of a conventional credit account 230 grace period (end of the present month) to the next bi-weekly user payment (first day or week in the following month) is typically 10 days or less. Since this timing can be important, and to ensure the timing does not stretch too long, the lender 220 may require the user 200 to have funds deposited automatically from the funding or paying party (e.g., employer, trust administrator, etc.) FIG. 2B further shows how the loan account 210 principal decreases with each continuing payment. For example, as shown in step 260, the user's next fund pays down the principal balance, in step 263, from $97,000 to $95,000. As before, since the user 200 applied the entire fund 260 to the loan principal 217, the user spends the credit account 230 balance, step 267, to accommodate monthly expenses (not to exceed $460). Step 270 shows that the user 200 deposits a next bi-weekly fund into the loan account 210, such that, as shown in step 273, the principal drops from $95,000 to $93,000. Moreover, as shown in step 265, since the credit account 230 has not yet closed (i.e., not the end of the second month), the lender's 220 funds to apply to the credit account 230 are $0. At the end of the credit account 230 grace period, step 277 shows that the credit account 230 pays the loan account 210 interest of $540, such that the credit account balance rises from $460 (user expenses) to $1,000 (user expenses+monthly loan interest). At the end of, or just prior to, the credit account grace period, step 275 shows that the lender 220 then pays off the credit account 230 balance of $1,000 in full. As shown in step 273, this causes the principal balance 217 to rise from $93,000 to $94,000, which ultimately decreases again when user 200 deposits the next user payment (not shown) for the next month. As this sequence continues for each month, the daily amortized monthly interest amount decreases as the principal decreases, allowing the user either to apply a greater amount of the user payment to principal, or freeing up some of the user payment as extra cash. Accordingly, FIG. 2B illustrates one implementation of a payoff sequence in which each user 200 applies continuing funds directly toward the loan account 210 principal 217. There are, however, additional ways in which these concepts can be implemented within the context of the present invention. For example, a lender 220 can configure the revolving loan account 220 with debit, credit, and/or check writing privileges, and can further allow such privileges up to a certain access limit. In some cases, the check writing privileges can exceed the original loan principal, for example, based on the lender's determination of equity in the purchased item. As such, the monthly loan interest 218 would be paid directly with reference to equity in the purchased item, such as up to the amount by which the principal has been paid down from the initial loan amount. Alternatively, the lender 220 can set the debit, credit, and/or check writing privileges for an access limit not to exceed a certain loan to value (LTV) ratio. In another implementation, the lender 220 can configure an ordinary checking account with an overdraft limit that is sufficient to cover the monthly loan interest. The user 200 may then elect not to deposit all of the user payments into the loan account 210. For example, the user can direct a portion of the funds to be directed to the loan account 210, and another portion of the funds to be directed into the ordinary checking account. As such, the user 200 would be allowed to write checks, or use a debit/credit card attached to the ordinary checking account up to any available access limit, such as for any available balance. At the end of the month, the lender 220 can then pay the monthly loan interest 218 with the overdraft portion of the account, payoff the overdraft portion with the revolving loan account 210, and then fund the checking account by a predetermined amount, such as an access limit previously agreed-to between the lender and the user 200. As such, one will appreciate that there are a wide variety of ways in which the disclosed concepts can be implemented. The present invention may also be described in terms of methods comprising functional steps and/or non-functional acts. FIGS. 3 and 4 illustrate exemplary flow charts for paying a loan principal, such that equity in the property is increased more rapidly that otherwise possible without substantially burdening a user's monthly expenses. The methods of FIGS. 3 and 4 will be discussed with respect to schematic diagrams illustrated in FIGS. 2A and 2B. As shown in FIG. 3, a method for paying a loan principal comprises an act 300 of receiving a first user payment into a loan account. Act 300 includes receiving a first user payment into a loan account, wherein the first user payment pays down a first portion of the loan principal. For example, a lender 200 can receive a user payment 240 in the form of a manual deposit, or an automatic EFT, and apply 243 the user payment directly to the existing loan principal balance. In addition, the method comprises an act 310 of applying a first portion of the first user payment to the loan principal. For example, when the user payment is applied to the loan account 210, all of the user payment can be applied directly to the loan principal 217, or a portion can be applied to the loan principal 217, and another portion can be applied to a cash account. FIG. 3 also shows that the method further comprises a functional step 320 for reducing a loan principal and credit account in part by momentarily raising the loan principal. Step 320 includes reducing a loan principal and credit account in part by momentarily raising the loan principal, such that the loan account pays off a credit account that was used to help cover loan expenses without incurring a greater interest penalty. Although step 320 can comprise any number or order of corresponding non-functional acts, FIG. 3 shows that step 320 comprises an act 330 of paying the loan interest 218 with a credit account. Act 330 comprises paying at least monthly interest on the loan account with a credit account, wherein the credit account comprises a credit limit and a grace period. For example, the lender 220, or a third party vendor, can provide a user 200 with a credit, account 230 that has a sufficient credit limit to cover the monthly loan interest 218 and the user's monthly budgetary expenses 205. The lender 220, or third party vendor, can then pay the monthly loan interest 218, step 277, at the end of the credit account grace period. From the perspective of loan account 210, loan account 210 receives a payment for at least monthly interest 218 from credit account 230. By way of explanation, the lender 220 can provide the credit account 230 itself, or through a company that is owned by the lender 220, through a subsidiary of a company that owns the lender 220, or that is a parent company of the lender 220. Thus, reference to a “third party provider” refers to a provider that is wholly unrelated to—or “different” from—the lender in the ordinary course of business. Step 320 further comprises an act 340 of incurring a further debt on the loan to pay off the credit account. Act 340 includes incurring a further debt on the loan (thus, causing the amount owed on the loan to increase) to pay off the credit account in full at the end of the credit account grace period. For example, after a credit account 230 has been used (e.g., steps 247, 257) to pay the user's monthly expenses 205, and the monthly loan interest 218, the lender 220 can raise the loan account 210 balance an amount sufficient to pay off the credit account 230, e.g., depicted in steps 253 and 255. Since this occurs before or at the end of the credit account 230 grace period, the lender 220 pays off the credit account 230 balance without incurring additional interest or penalties. In one embodiment, the loan account 210 is a home equity line of credit that raises automatically by a payment made to the credit account balance, such that the lender need not necessarily take extra steps to raise the loan account 210 balance. In addition, step 320 comprises an act 350 of receiving a second user payment into the loan account. Act 350 includes receiving a second user payment into the loan account. For example, before or after the lender 220 has applied the loan account 210 to pay off the credit account 230 balance (e.g., step 255), the user can deposit a next user payment (e.g., step 250 or step 260) into the loan account 210. Depending on the credit card grace period, this can occur before the end of the month (i.e., step 250), or sometime after the beginning of the next month (i.e., step 260). Step 310 further comprises an act 360 of applying a first portion of the second user payment to the further debt. Act 360 includes applying at least a first portion of the second user payment to the further debt on the loan. For example, depending on the timing of the second user payment relative to the further debt on the loan account (e.g., before or after the further debt), a portion (all or less) of the second user payment may be applied to the loan principal 217 before the loan account 210 is raised to cover the credit account balance. In such a case, the further debt on the loan account will have been covered in advance by the first portion of the second user payment. If the further debt on the loan occurs before or at substantially at the time of the second user payment, then the first portion of the user payment could be thought of as being applied directly to the further debt on the loan. Step 310 further comprises an act 370 of applying a second portion of the second user payment to the loan principal. Act 370 includes applying a second different portion of the second user payment to the loan principal. For example, if the first portion of the second user payment is just enough to cover the further debt on the loan, the second portion of the second user payment comprises one or more remainders of the second user payment. Thus, the second different portion of the second user payment can be applied directly to the loan principal 217, while yet another portion (e.g., a third different portion) of the second user payment can be applied to another user account. FIG. 4 illustrates a method in which a lender provides a user with a loan program that can pay the loan account, such that equity in the property is increased more rapidly that otherwise possible without substantially burdening a user's monthly expenses. In particular, FIG. 4 shows a method comprising a functional step 400 for managing a loan balance with multiple accounts in order to help a user rapidly decrease the loan balance. Step 400 includes automatically managing a loan balance with multiple accounts, such that the lender can help the user make frequent, large payments to the loan principal with relative efficiency. For example, the lender 220 can implement computer-executable instructions, or software, that identify one or more accounts for a user, and that coordinate the transition of payments between two or more accounts. In one implementation, the software is configured such that the user applies maximum payments to principal without incurring additional interest penalties. Although step 400 can comprise any number or order of corresponding non-functional acts, FIG. 4 shows that step 400 comprises an act 410 of providing a user with a revolving loan account. Act 410 includes providing a user with a revolving loan account, the loan account having a loan principal and a monthly loan interest. For example, in response to a user's request to finance a large purchase item, the lender 220 can offer a user a loan program that includes a revolving loan account 210 secured to the purchase item, wherein the loan comprises a principal portion 217 and a monthly interest portion 218. In at least one implementation, the lender 220 amortizes the monthly interest on a daily basis. Step 400 further comprises an act 420 of providing the user with a secondary account. Act 420 includes providing the user with a secondary account having a spending limit based at least on a monthly user budget, and the monthly loan interest. For example, the lender 220 can provide the user with a separate credit account 230 having a credit limit that supports a predetermined user budget 205 and a monthly loan account interest 218. Alternatively, the lender 220 can provide the user 200 with a separate checking account that comprises an overdraft privilege sufficient to cover the monthly loan interest 218. Still further, the lender 220 can provide the user 200 with check writing, debit, or credit privileges in conjunction with the revolving loan account 210 up to a given spending limit. In each case, the lender 220 configures the loan program so that, for example, the user 200 does not spend more in monthly expenses than are available based on any equity in the purchase item. Other limits, however, may be agreed to between the lender and the user. In any event, the lender 220 configures the loan program such that the user progresses toward paying the principal 217, rather than extending the loan account 210 debt after the period of one or more months. Step 400 further comprises an act 430 of paying the loan interest with the second account. Act 430 includes automatically paying the monthly loan interest with the second account. For example, the lender 220 can ensure set up the secondary account 230 to automatically pay the monthly loan interest 218, as identified in the loan account 210. In at least one implementation, the lender 220 does so by requiring the secondary account 230 to pay interest at a given time, such as at the end of a monthly cycle for the loan account 210. Alternatively, the lender 220 sets up the secondary account 230 to pay the monthly interest 218 at (or just prior to) the end of a grace period for the secondary account 230. In addition, FIG. 4 shows that the method comprises an act 440 of paying down the loan principal and the secondary account with one or more user payments. Act 440 includes automatically paying down the loan principal and the secondary account at least in part with one or more user payments, such that the principal is paid down each time at least one of the one or more user's payments are received. For example, the lender 220 can implement automatically deposited, bi-weekly employment payments (e.g., 240, 250) directly into the loan account 210. At least one of the user payments, e.g., step 253, has a portion applied to the loan account principle 217, and another portion that is applied to the monthly interest 218. Furthermore, with bi-weekly payments, at least another payment (e.g., step 243, or step 263) can be applied solely to the account principle 217. Accordingly, implementations of the present invention allow a user to pay down loan principal in a much more rapid fashion than otherwise possible. For example, a home loan of $268,000, and $59,000 in consumer debt can be paid off aggressively in approximately 8.67 years, without greatly burdening the user's monthly budget constraints. In another example, a loan of $100,000 can be paid off in 12 years using a less aggressive approach, while only paying $45,397 in interest using a 7% annual interest rate. Thus, implementations of the present invention provide users with a substantial savings compared with conventional loans. Furthermore, the lender can provide this loan payment program to the user in a very efficient manner, saving costs and/or creating revenue for lender. In one example, the savings to the user are great enough that the user can charge as much as $50 to $100 per month in service fees to the user. In another example, the savings are great enough to the user that the lender/provider of the secondary account (or credit account) can also charge another $50 to $100 in service fees to the user. Service fees such as these are, in some cases, greater than the lender or secondary account provider would otherwise see at the end of a loan term, and would only add from a few months to a couple of years to end of a loan. As such, the loan could be paid off in 9-12 years, as opposed to 7-8 years, still using a user budget that would be more appropriate for a 20-30 year pay off. Compared with paying the loan off in 20-30 years, implementations of the present invention represent a substantial savings to the user, and a benefit to the lender or account provider. Furthermore, since the loan relies primarily on the home or property value as a security interest, the user can treat the home as something of a liquid asset, such that the user can make cash withdrawals that are guaranteed against the home value. Thus, in at least some implementations, the home or property can be thought of a conventional automated teller machine (ATM). The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. The Field of the Invention This invention relates to systems, methods, and computer program products for debt reduction. 2. Background and Relevant Art Monetary debt, which and entails paying for an item at a later date, is a growing problem for many people. For example, a consumer can now finance any number of secured debts, such as homes, cars, property, expensive goods, as well as unsecured debts, such as items purchased through a credit card or line of credit, education loans, etc. In each case, paying for the item at a later date can add to the expense of the item, and therefore create an unanticipated financial burden on the user. In particular, most debts require that the consumer pay back the debt with a certain amount of interest that is amortized over time, making the items far more expensive in the long-run than when purchased initially. As shown in FIG. 1 , for example, a user ( 100 ) may purchase an item (e.g., a home 105 ) for a principal amount of $100,000 ( 117 ) by asking a lender ( 110 ) to finance the item ( 105 ) at a certain interest rate ( 118 ), such as an interest rate of 5%, amortized over 30 years. Using a simple interest calculation, the monthly payment ( 120 ) of principal ( 117 ) and interest ( 118 ) on such a purchase would be approximately $540, with the total amount paid on the loan being approximately $194,000. After making the final payment in the 30 year period, the user will have paid almost double ($194,000) the amount of the initial purchase ($100,000). In some cases, the financed items will appreciate in value over time, such that the value of the item is still greater than the total amount paid in the end. This, however, is not the case for many other depreciating items, such as debts to purchase cars, clothing, food, etc., which lose value with use over time In particular, depreciating items are typically not worth the amount paid for them with interest, especially at the time the consumer makes the last payment on the debt. For example, a payment of $100 in clothing (e.g., one or two pairs of pants) could accrue approximately $20 in interest assuming conventional interest rates, and assuming conventional minimum monthly payments. Thus, the used clothing is usually worth far less than paid initially by the time the final payment has been made (roughly a year in this example). This problem becomes far worse when the consumer fails to make timely payments, and hence incurs additional fees and interest rate increases. Accordingly, it is ideal in many cases to purchase an item up front, rather than paying at a later date (i.e., financing the item). While this sort of monetary discipline can be exercised for many types of wanted items, there are some necessary items that cannot ordinarily be purchased by most consumers without incurring at least some debt. For example, most people do not make enough money, or have enough cash on hand, to purchase a home with without incurring at least some debt. Furthermore, many people cannot afford even to purchase a home with financing that allows the home to be paid off within a relatively short time to minimize their interest payments, such as a time period of 10-15 years. In particular, short term loans, such as 10-15 year home loans, typically require a high monthly payment. This can be particularly difficult for a user since mortgage payments are usually required in a single monthly payment, such that the user cannot spread the total monthly payment in two partial payments, consistent with the user's bi-weekly paychecks. Thus, it is fairly common for users to purchase a home with financing that allows the home to be paid off within approximately 30 years. While this provides the benefit of a relatively low monthly payment, the total interest paid on the home is extremely high, often twice the value of the home. Furthermore, this means the user is likely to hold a significant amount of debt on a home up until (or just after) the user is ready to retire, depending on when the user purchased the home. Accordingly, some programs have been developed to help ease the debt burdens some users may face with large loans. In particular, some programs, such as bi-weekly payment programs, offer a person to pay down a debt, such as a home debt, more quickly than possible under a 30-year loan, without significantly burdening the user's monthly budget. For example, assuming a monthly mortgage costs $1,000 for a user. A bi-weekly program might allow the user to pay $542 every two weeks, such that the user has overpaid by $84 each month. The program administrator saves the extra $84 until $1000 has been saved up, and then makes an extra payment into the loan at the end of the year. Making an extra payment such as this has been shown to reduce the total term of the loan from approximately 30 years to approximately 22 or 23 years, representing a significant interest savings for the user. Unfortunately, payoff periods of 20 or more years can still represent a significant burden to many users in terms of time and cost, particularly those users who delay purchasing a home until they are somewhat advanced in age. For example, users who purchase homes while in their forties will still be paying down the debt as they approach retirement. Furthermore bi-weekly programs are not typically cost-free. With reference to the prior example, the program administrator might require the user to pay $684 per check (rather than $584) to operate the program, such that the user pays an additional approximately $200 a month ($100 extra every two weeks) in service fees. As such, in some cases, a user may believe that the benefits of reducing the term of the debt from 30 years to 20 years is difficult to justify compared to the burden of paying extra service fees with the reapportioned loan amounts each month. For example, biweekly programs, with their service fees, may be too expensive for some users who struggle to pay even the standard monthly debt payment. Still further, bi-weekly programs generally require a person to make additional efforts with their loans, after having spent considerable effort negotiating, procuring, and signing the original home loan. Accordingly, an advantage in the art can be realized with systems, methods, and computer program products that help a user pay off large debts in a relatively short period of time, such as paying off a home debt in less than 10 years, without substantially burdening the user's monthly budget for other expenses. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention solves one or more of the foregoing problems in the prior art with systems, methods, and computer program products for helping a user pay off a large debt, such as a home debt, in less than 10-15 years, where the debt would otherwise be due in 20-30 years. In particular, implementations of the present invention allow a user to pay off a large home debt—either from the purchase of a home or from a refinance of an existing loan, including consumer debt—much quicker than otherwise possible, while allowing a user to maintain current monthly expenses. For example, in one implementation, a user obtains a large loan from a lender, using a revolving loan account. The lender (or third party provider) further provides the user with a credit card having a credit limit and a grace period, where the credit limit is sufficient to cover the user's monthly personal expenses, as well as cover the monthly interest on the revolving loan. The user then deposits each user payment, such as a user paycheck, or such amount as the borrower sees fit, into the revolving loan account, such that the principal on the loan is paid down with the frequency and amount that the user is paid (e.g., bi-weekly or more). The credit account is used to pay off the daily interest that is owed monthly on the revolving loan. Also at the end of the credit account billing period, and further at the end of the credit card grace period, the lender pays off the credit card balance using the revolving loan account, such that the lender momentarily raises the revolving loan account balance, albeit slightly. When the lender receives the next user paycheck, the lender applies the user's payments, such as the user's paycheck, against the increased loan principal. Additional features and advantages of exemplary implementations of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of such exemplary implementations. The features and advantages of such implementations may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter. | 20040715 | 20070807 | 20050317 | 71905.0 | 2 | PATEL, JAGDISH | SYSTEM AND METHOD FOR PAYING DOWN DEBT USING AN EQUITY LOAN REVOLVING LINE OF CREDIT | MICRO | 0 | ACCEPTED | 2,004 |
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10,892,002 | ACCEPTED | Method and system for controlling a mobile machine | Embodiments of the present invention recite system for controlling a mobile machine. In one embodiment the system comprises a position determining component for determining the geographic position of the mobile machine. The system further comprises a steering component for controlling the steering mechanism of the mobile machine in response to a message. The system further comprises a control component coupled with the position determining component and with the steering component. The control component generates a message to the steering component in response to receiving position data from the position determining component. | 1. A system for controlling an agricultural vehicle, said system comprising: a position determining component for determining the geographic position of said agricultural vehicle; an electric steering component for controlling the steering mechanism of said agricultural vehicle in response to a message; and a control component coupled with said position determining component and with said steering component, said control component for generating said message in response to receiving position data from said position determining component. 2. The system of claim 1 wherein said position determining system is a ground based position determining system. 3. The system of claim 1 wherein said position determining system is a satellite based position determining system. 4. The system of claim 3 wherein said satellite based position determining system is selected from the group consisting of a global positioning system (GPS) system, a differential GPS system, a real-time kinematics (RTK) system, a networked RTK system, a GLONASS system, and a Galileo system. 5. The system of claim 1 wherein said control component generates a control voltage to said electric steering component. 6. The system of claim 1 further comprising a serial communication bus which communicatively couples said control component, said steering component, and said position determining component. 7. The system of claim 7 wherein said serial communication bus is substantially compliant with the controller area network (CAN) protocol. 8. The system of claim 1 wherein said control component is further operable for controlling a hydraulic steering component that is coupled with the steering mechanism of said agricultural vehicle. 9. The system of claim 1 wherein said steering component comprises: an electric motor coupled with said control component; and an actuator device coupled with said electric motor and configured to control the steering mechanism of said agricultural vehicle. 10. The system of claim 9 wherein said electric motor is directly coupled with said actuator device. 11. The system of claim 9 wherein said electric motor is coupled with said actuator device via a gear. 12. The system of claim 9 wherein said electric motor is selected from the group consisting of a permanent magnet brush direct current (DC) motor, a brushless DC motor, a stepper motor, and an alternating current (AC) servo motor. 13. The system of claim 9 wherein said electric motor is coupled with a steering column of said agricultural vehicle and wherein said actuator device comprises a drive wheel which controls a steering wheel of said steering mechanism. 14. The system of claim 13 wherein said actuator device controls said steering wheel via a sub wheel which is coupled with said steering wheel. 15. The system of claim 9 wherein said actuator device is coupled with a steering shaft of said agricultural vehicle. 16. The system of claim 1 further comprising a detection component for determining when a user is steering said agricultural vehicle and for initiating disengagement of said steering component in response to said determining. 17. A control component for controlling an agricultural vehicle, said control component comprising: a vehicle guidance system for determining a course correction for said agricultural vehicle based upon position data received from a position determining component; and a steering controller coupled with said vehicle guidance system and for generating a steering command based upon said course correction, and wherein said steering command is conveyed to at least one of an electric steering component and a hydraulic steering component coupled with the steering mechanism of said agricultural vehicle. 18. The control component of claim 17 wherein said control component and said position determining component communicate via a serial communication bus. 19. The control component of claim 18 wherein said serial communication bus is substantially compliant with the controller area network (CAN) protocol. 20. The control component of claim 17 wherein said position determining component is a ground based position determining system. 21. The control component of claim 17 wherein said position determining component is a satellite based position determining system. 22. The control component of claim 21 wherein said satellite based position determining component is selected from the group consisting of a global positioning system (GPS) system, a differential GPS system, a real-time kinematics (RTK) system, a networked RTK system, a GLONASS system, and a Galileo system. 23. The control component of claim 17 wherein a control voltage is conveyed to either of said electric steering component and said hydraulic steering component in response to said steering command. 24. The control component of claim 17 wherein said electric steering component comprises: an electric motor coupled with a steering column of said agricultural vehicle; and an actuator device coupled with said electric motor and configured to control the steering mechanism of said agricultural vehicle. 25. The control component of claim 24 wherein said electric motor is directly coupled with said actuator device. 26. The control component of claim 24 wherein said electric motor is coupled with said actuator device via a gear. 27. The control component of claim 24 wherein said electric motor is selected from the group consisting of a permanent magnet brush direct current (DC) motor, a brushless DC motor, a stepper motor, and an alternating current (AC) servo motor. 28. The control component of claim 24 wherein said actuator device comprises a drive wheel which is coupled with the steering wheel of said agricultural vehicle. 29. The control component of claim 28 wherein said drive wheel is coupled with the steering wheel via a sub wheel which is coupled with the steering wheel. 30. The control component of claim 24 wherein said actuator device is coupled with a steering shaft of said agricultural vehicle. 31. The control component of claim 17 wherein said electric steering component further comprises: a detection component for determining when a user is steering said agricultural vehicle and for initiating disengagement one of said electric steering component and said hydraulic steering component in response to said determining. 32. A method for controlling an agricultural vehicle comprising: utilizing a position determining component to determine the geographic position of said agricultural vehicle; using a control component to generate a steering command based upon the geographic position of said agricultural vehicle; and using an electric steering component to control the steering mechanism of said agricultural vehicle in response to said steering command. 33. The method as recited in claim 32 wherein said position determining component comprises a ground based position determining system. 34. The method as recited in claim 32 wherein said position determining system comprises a satellite based position determining component. 35. The method as recited in claim 34 wherein said satellite based position determining component is selected from the group consisting of a global positioning system (GPS) system, a differential GPS system, a real-time kinematics (RTK) system, a networked RTK system, a GLONASS system, and a Galileo system. 36. The method as recited in claim 32 further comprising: generating a control voltage in response to said steering command. 37. The method as recited in claim 32 further comprising: using a serial communication bus to communicatively couple said control component and said position determining component. 38. The method as recited in claim 37 wherein said serial communication bus is substantially compliant with the controller area network (CAN) protocol. 39. The method as recited in claim 32 wherein said control component is further operable for controlling a hydraulic steering component. 40. The method as recited in claim 32 wherein said steering component comprises: an electric motor coupled with said control component; and an actuator device coupled with said electric motor and configured to control the steering mechanism of said agricultural vehicle. 41. The method as recited in claim 40 wherein said electric motor is directly coupled with said actuator device. 42. The method as recited in claim 40 wherein said electric motor is coupled with said actuator device via a gear. 43. The method as recited in claim 40 wherein said electric motor is selected from the group consisting of a permanent magnet brush direct current (DC) motor, a brushless DC motor, a stepper motor, and an alternating current (AC) servo motor. 44. The method as recited in claim 40 wherein said actuator device comprises a drive wheel which controls a steering wheel of said steering mechanism. 45. The method as recited in claim 40 wherein said actuator device controls said steering wheel via a sub wheel which is coupled with said steering wheel. 46. The method as recited in claim 40 wherein said actuator device is coupled with a steering shaft of said agricultural vehicle. 47. The method as recited in claim 32 further comprising: determining when a user is steering said agricultural vehicle; and disengaging said steering component in response to said determining. | FIELD OF THE INVENTION Embodiments of the present invention are directed to controlling a mobile machine. More specifically, embodiments of the present invention relate to a guidance system for controlling a mobile machine. BACKGROUND OF THE INVENTION Operating agricultural vehicle such as tractors and harvesters often requires highly repetitive operations. For example, when plowing or planting a field, an operator must make repeated passes across a field. Due to the repetitive nature of the work and irregularities in the terrain, gaps and overlaps in the rows of crops can occur. This can result in damaged crops, overplanting, or reduced yield per acre. As the size of agricultural vehicles and farming implements continues to increase, precisely controlling their motion becomes more important. Guidance systems are increasingly used for controlling agricultural and environmental management equipment and operations such as road side spraying, road salting, and snow plowing where following a previously defined route is desirable. This allows more precise control of the vehicles than is typically realized than if the vehicle is steered by a human. Many rely upon furrow followers which mechanically detect whether the vehicle is moving parallel to a previously plowed plant furrow. However, these guidance systems are most effective in flat terrain and when detecting furrows plowed in a straight line. Additionally, many of these systems require factory installation and are too expensive or inconvenient to facilitate after market installation. SUMMARY OF THE INVENTION Accordingly, a need exists for system which is suitable guiding mobile machines such as agricultural vehicles. While meeting the above stated need, it is also desirable that the guidance system is suitable for after market installation in those vehicles. Embodiments of the present invention recite system for controlling a mobile machine. In one embodiment the system comprises a position determining component for determining the geographic position of the mobile machine. The system further comprises a steering component for controlling the steering mechanism of the mobile machine in response to a message. The system further comprises a control component coupled with the position determining component and with the steering component. The control component generates a message to the steering component in response to receiving position data from the position determining component. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the invention. Unless specifically noted, the drawings referred to in this description should be understood as not being drawn to scale. FIGS. 1A and 1B show an exemplary system for controlling a mobile machine in accordance with embodiments of the present invention. FIG. 2 shows an exemplary system architecture in accordance with embodiments of the present invention. FIGS. 3A and 3B show side and top views respectively of a system for controlling a mobile machine in accordance with embodiments of the present invention. FIGS. 4A and 4B show side and top views respectively of a system for controlling a mobile machine in accordance with embodiments of the present invention. FIGS. 5A and 5B show side and top views respectively of a system for controlling a mobile machine in accordance with embodiments of the present invention. FIG. 6 is a flow chart of a method for controlling an agricultural vehicle in accordance with embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. While the present invention will be described in conjunction with the following embodiments, it will be understood that they are not intended to limit the present invention to these embodiments alone. On the contrary, the present invention is intended to cover alternatives, modifications, and equivalents which may be included within the spirit and scope of the present invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention. FIG. 1 is a block diagram of an exemplary system 100 for controlling a mobile machine 105 in accordance with embodiments of the present invention. In FIG. 1, a position determining system is coupled with a control component 120 and a steering component 130 via a communication network or coupling 115. Additionally, system 100 may comprise an optional keypad 140 and/or a terrain compensation module component (e.g., TCM 150) which are also coupled with coupling 115. In embodiments of the present invention, coupling 115 is a serial communications bus. In one embodiment, coupling 115 is compliant with, but not limited to, the controller area network (CAN) protocol. CAN is a serial bus system which was developed for automotive use in the early 1980s. The Society of Automotive Engineers (SAE) has developed a standard CAN protocol, SAE J1939, based upon CAN specification 2.0. The SAE J1939 specification provides plug-and-play capabilities and allows components from various suppliers to be easily integrated in an open architecture. Position determining system 110 determines the geographic position of mobile machine 105. For the purposes of the present invention, the term “geographic position” means the determining in at least two dimensions (e.g., latitude and longitude), the location of mobile machine 105. In one embodiment of the present invention, position determining system 110 is a satellite based position determining system and receives navigation data from satellites via antenna 107 of FIG. 1B. Examples of satellite based position determining systems include the global positioning system (GPS) navigation system, a differential GPS system, a real-time kinematics (RTK) system, a networked RTK system, etc. While the present embodiment recites these position determining systems specifically, it is appreciated that embodiments of the present invention are well suited for using other position determining systems as well such as ground-based position determining systems, or other satellite-based position determining systems such as the GLONASS system, or the Galileo system currently under development. In embodiments of the present invention, control component 120 receives position data from position determining system 110 and generates commands for controlling mobile machine 105. In embodiments of the present invention, mobile machine 105 is an agricultural vehicle such as a tractor, a harvester, etc. However, embodiments of the present invention are well suited for controlling other vehicles such as snow plows, road salting, or roadside spraying equipment as well. In one embodiment, is response to position data received from position determining system 110, control component 120 generates a message (e.g., a steering command) to steering component 130 which then controls the steering mechanism of mobile machine 105. In embodiments of the present invention, control component 120 is operable for generating steering commands to an electrical steering component and a hydraulic steering component depending upon the configuration of system 100. In embodiments of the present invention, keypad 130 provides additional input/output capabilities to system 100. In embodiments of the present invention, keypad 130 may also comprise a device drive 131 which allows reading a media storage device such as a compact disk (CD), a digital versatile disk (DVD), a memory stick, or the like. This allows, for example, integrating data from various software applications such as mapping software in order to facilitate controlling the movement of mobile machine 105. For example, field boundaries can be easily input into system 100 to facilitate controlling the movement of mobile machine 105. TCM 150 provides the ability to compensate for terrain variations which can reduce the precision of position determining system 110 in determining the geographic position of mobile machine 105. For example, when traversing a hillside, the antenna 107 of the position determining system 110 can be displaced to one side or the other with respect to the center line of mobile machine 105, thus causing errors in determining the geographic position of mobile machine 105. As a result, gaps or overlaps can occur when plowing across contoured terrain is being performed. TCM 150 can detect the magnitude of displacement of antenna 107 with respect to the center line of mobile machine 105 (e.g., due to roll, pitch, and yaw) and send signals which allow control component 120 to generate steering commands which compensate for the errors in determining the geographic position of mobile machine 105. It is appreciated that the components described with reference to FIG. 1 may be implemented as separate components. However, in embodiments of the present invention, these components may be integrated as various combinations of discreet components, or as a single device. FIG. 2 shows an exemplary system architecture 200 in accordance with embodiments of the present invention. In the embodiment of FIG. 2, control component 120 comprises a vehicle guidance system 210 which is coupled with a steering controller 220. It is appreciated that in embodiments of the present invention, vehicle guidance system 210 and steering controller 220 may be implemented as a single unit, or separately. Implementing steering controller 220 separately is advantageous in that it facilitates implementing the present invention as an after market kit which can be easily added to an existing vehicle navigation system. As a result, the costs for components and for installation of the control system of the present invention are reduced. However, embodiments of the present invention are well suited to be factory installed as original equipment for mobile machine 105 as well. In embodiments of the present invention, vehicle guidance system 210 uses position data from position determining system 110, user input such as a desired pattern or direction, as well as vector data such as desired direction and distance to determine course corrections which are used for guiding mobile machine 105. Roll, pitch, and yaw data from TCM 150 may also be used to determine course corrections for mobile machine 105. For purposes of the present invention, the term “course correction” means a change in the direction traveled by mobile machine 105 such that mobile machine 105 is guided from a current direction of travel to a desired direction of travel. In embodiments of the present invention, vehicle guidance system 210 is a commercially available guidance system such as the AgGPS® guidance system manufactured by Trimble Navigation Ltd. of Sunnyvale Calif. Additional data used to determine course corrections may also comprise swath calculation which takes into account the width of various implements which may be coupled with mobile machine 105. For example, if a harvester can clear a swath of 15 feet in each pass, vehicle guidance system 210 may generate steering commands which cause mobile machine 105 to move 15 feet to one side in the next pass. Vehicle guidance system 210 may also be programmed to follow straight or curved paths which is useful when operating in irregularly shaped or contoured fields or in fields disposed around a center pivot. This is also useful in situations in which the path being followed by mobile machine 105 is obscured. For example, an operator of a snowplow may not be able to see the road being cleared due to the accumulation of snow on the road. Additionally, visibility may be obscured by snow, rain, or fog. Thus, it would be advantageous to utilize embodiments of the present invention to guide mobile machine 105 in these conditions. In embodiments of the present invention, position determining component 110 may be integrated into vehicle guidance system 210 or may be a separate unit. Additionally, as stated above with reference to FIG. 1, position determining component 110, control component 120 and steering component 130 may be integrated into a single unit in embodiments of the present invention. In embodiments of the present invention, the course correction calculated by vehicle guidance system 210 is sent from vehicle guidance system 210 to steering controller 220. Steering controller 220 translates the course correction generated by guidance system 210 into a steering command for manipulating the steering mechanism of mobile machine 105. Steering controller 220 generates a message conveying the steering command to steering component 130. In embodiments of the present invention, the communicative coupling between vehicle guidance system 210, steering controller 220 and steering component 130 is accomplished using coupling 115 (e.g., a serial bus, or CAN bus). In embodiments of the present invention, steering component 130 may comprise an electric steering component 131, or a hydraulic steering component 132. Thus, as shown in FIG. 2, steering controller 220 comprises a first output 221 for coupling steering controller 220 with electric steering component 131, and a second output 222 for coupling steering controller 220 with hydraulic steering component 132. Because coupling 115 may be compliant with the CAN protocol, plug and play functionality is facilitated in system 200. Therefore, in embodiments of the present invention, steering controller can determine which steering component it is coupled with depending upon which output of steering controller 220 is used. Steering controller 220 then generates a message, based upon the steering component with which it is coupled, which causes the steering component to actuate the steering mechanism of mobile machine 105. For example, if steering controller 220 determines that output 221 is being used, it generates a steering command which is formatted for controlling electric steering component 131. If steering controller 220 determines that output 222 is being used, it generates a steering command which is formatted for controlling hydraulic steering component 132. FIGS. 3A and 3B show side and top views respectively of a system 300 for controlling a mobile machine in accordance with embodiments of the present invention. In the embodiment of FIG. 3A, a steering component (e.g., electric steering component 131 of FIG. 2) comprises an electric motor 310 which is coupled with an actuator device via a shaft 312. In the embodiment of FIG. 3A, actuator device comprises a drive wheel 311 which is in contact with steering wheel 330 of mobile machine 105. In embodiments of the present invention, electric motor 310 may be directly coupled with drive wheel 311, or may be coupled via a low ratio gear (not shown). Using these methods to couple electric motor 313 and drive wheel 311 are advantageous in that a smaller electric motor can be used while still generating sufficient torque to control steering wheel 330. Thus, if a user wants to manually steer mobile machine 105, the user will encounter less resistance from electric motor 310 when it is disengaged. Electric steering component 131 further comprises a motor control unit 313 is coupled with electric motor 310 and with a control component 120 of FIG. 2 via coupling 115. In FIG. 3A, electric motor 310 is coupled with the steering column 340 via a bracket 320. It is appreciated that in embodiments of the present invention, electric motor 310 may be coupled with steering column 340 using another apparatus than bracket 320. For example, in one embodiment, electric motor 310 may be coupled with a bracket which is attached via suction cups with the windshield or dashboard of mobile machine 105. In another embodiment, electric motor 310 may be coupled with a pole which is extended between the floor and roof of mobile machine 105. Furthermore, while the present embodiment shows motor control unit 313 directly coupled with electric motor 310, embodiments of the present invention are well suited to utilize other configurations. For example, in one embodiment motor control unit 313 may be implemented as a sub-component of control unit 120 and may only send a control voltage to electric motor 310 via an electrical coupling (not shown). In another embodiment, motor control unit 313 may be implemented as a separate unit which is communicatively coupled with control unit 120 via coupling 115 and with electric motor 310 via an electrical coupling (not shown). In embodiments of the present invention, drive wheel 311 is coupled with steering wheel 330 with sufficient friction such that rotation of drive 311 causes rotation of steering wheel 330. In embodiments of the present invention, a spring (not shown) maintains sufficient pressure for coupling drive wheel 311 with steering wheel 330. However, the spring does not maintain sufficient pressure between drive wheel 311 and steering wheel 330 to pinch a user's fingers if, for example, the user is manually steering mobile machine 105 and the user's fingers pass between drive wheel 311 and steering wheel 330. In embodiments of the present invention, electric motor 310 is reversable, thus, depending upon the steering command sent from control component 120, motor control unit 313 controls the current to electric motor 310 such that it rotates in a clockwise of counter-clockwise direction. As a result, steering wheel 330 is turned in a clockwise or counter-clockwise direction as well. Typically, the current running through electric motor 310 is calibrated so that drive wheel 311 is turning steering wheel 330 without generating excessive torque. This facilitates allowing a user to override electric steering component 131. In embodiments of the present invention, electric motor 310 may be a permanent magnet brush direct current (DC) motor, a brushless DC motor, a stepper motor, or an alternating current (AC) motor. In embodiments of the present invention, motor control unit 313 can detect when a user is turning steering wheel 330 in a direction counter to the direction electric steering component 131 is turning. For example, a shaft encoder (not shown) may be used to determine which direction shaft 312 is turning. Thus, when a user turns steering wheel 330 in a direction which counters the direction electric motor 310 is turning, the shaft encoder detects that the user is turning steering wheel 330 and generates a signal to motor control unit 313. In response to determining that a user is turning steering wheel 330, motor control unit 313 can disengage the power supplied to electric motor 310. As a result, electric motor 310 is now freewheeling and can be more easily operated by the user. In another embodiment, motor control unit 313 when steering wheel 330 is turned counter to the direction electric motor is turning, a circuit in motor control unit 313 detects that electric motor 310 is stalling and disengages the power supplied to electric motor 310. In another embodiment, a switch detects the rotation of steering wheel 330 and sends a signal to motor control unit 313. Motor control unit 313 can then determine that the user is manually steering mobile machine 105 and disengage electric motor 310. As a result, when a user turns steering wheel 330, their fingers will not be pinched if they pass between drive wheel 311 and steering wheel 330 because electric motor 310 is freewheeling when the power is disengaged. Embodiments of the present invention are advantageous over conventional vehicle control systems in that it can be easily and quickly installed as an after market kit. For example, conventional control systems typically control a vehicle using solenoids and hydraulic flow valves which are coupled with the power steering mechanism of the vehicle. These systems are more difficult to install and more expensive than the above described system due to the higher cost of the solenoids and hydraulic flow valves as well as the additional labor involved in installing the system. The embodiment of FIG. 3 can be easily bolted onto steering column 340 and coupled with steering controller 220. Additionally, electric motor 310 can be fitted to a variety of vehicles by simply exchanging bracket 320 for one configured for a particular vehicle model. Furthermore, embodiments of the present invention do not rely upon furrow feelers which typically must be raised from and lowered into a furrow when the end of the furrow is reached. As a result, less time is lost in raising or lowering the furrow feeler. FIGS. 4A and 4B show side and top views respectively of a system 400 for controlling a mobile machine in accordance with embodiments of the present invention. In FIG. 4A, the steering component (e.g., electric steering component 131 of FIG. 2) comprises an electric motor 410 which is coupled with drive wheel 411 via shaft 412 and a motor control unit 413. Motor control unit 413 couples electric motor 410 with steering controller 220 of FIG. 2. In FIG. 4A, electric motor 410 is with steering column 440 via bracket 420. In the embodiment of FIGS. 4A and 4B, drive wheel 411 is coupled with a sub wheel 431 which is coupled with steering wheel 330 via brackets 432. In the embodiment of FIGS. 4A and 4B, electric motor 410 turns in a clockwise or counter-clockwise direction depending upon the steering command received by motor control unit 413. As a result, drive wheel 411 causes sub wheel 431 to turn in clockwise or counter clockwise direction as well. Utilizing sub wheel 431 prevents a user's fingers from being pinched between steering wheel 430 and drive wheel 411 if the user chooses to manually steer the vehicle. In embodiments of the present invention, sub wheel 431 can be easily and quickly coupled with steering wheel 430 by, for example, attaching brackets 432 to the spokes of steering wheel 430. FIGS. 5A and 5B are side and sectional views respectively of a system 500 for controlling a mobile machine in accordance with embodiments of the present invention. In FIG. 5A, the steering component (e.g., electric steering component 131 of FIG. 2) comprises an electric motor 510 which is coupled with gear 511 via shaft 512 and with a motor control unit 513. Motor control unit 413 couples electric motor 510 with steering controller 220 of FIG. 2. In FIG. 5A, electric motor 510 is coupled with steering column 540. FIG. 5B is a section view of system 500 and shows steering shaft 550 disposed within steering column 540. A gear 551 couples steering shaft 550 with gear 511 of electric steering component 131. In the present embodiment, electric motor 510 turns in a clockwise or counter clockwise direction depending upon the steering command received by motor control unit 513. As a result, gear 511 also turns in a clockwise or counter clockwise direction, thus causing steering shaft 550 to turn due to the force conveyed by gear 551. While the present embodiment recites coupling electric steering component 131 with steering shaft 550 using gears, embodiments of the present invention are well suited for using other mechanical couplings such as a gear and chain, a belt and pulleys, etc. FIG. 6 is a flow chart of a method 600 for controlling an agricultural vehicle in accordance with embodiments of the present invention. In step 610 of FIG. 6, a satellite based position determining component is utilized to determine the geographic position of an agricultural vehicle. As described above with reference to FIG. 1, position determining component 110 is a satellite based position determining system such as global positioning system (GPS) navigation system, a differential GPS system, a real-time kinematics (RTK) system, a networked RTK system, etc. Position determining system determines the location of mobile machine 105 in at least two dimensions in embodiments of the present invention. In step 620 of FIG. 6, a control component is used to generate a steering command based upon the geographic position of the agricultural vehicle. As described above with reference to FIG. 2, control component 120 is used to generate steering commands for mobile machine based upon geographic data received from position determining component 110. In embodiments of the present invention, control component 120 comprises a vehicle guidance system (e.g., 210 of FIG. 2) which is coupled with a steering controller (e.g., 220 of FIG. 2). Vehicle guidance system 210 uses the position data received from position determining component 110 to determine course corrections for mobile machine 105. Steering controller 220 translates the course corrections into steering commands In step 630 of FIG. 6, a steering component is used to control the steering mechanism of the agricultural vehicle in response to the steering command. The preferred embodiment of the present invention, a method and system for controlling a mobile machine, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Operating agricultural vehicle such as tractors and harvesters often requires highly repetitive operations. For example, when plowing or planting a field, an operator must make repeated passes across a field. Due to the repetitive nature of the work and irregularities in the terrain, gaps and overlaps in the rows of crops can occur. This can result in damaged crops, overplanting, or reduced yield per acre. As the size of agricultural vehicles and farming implements continues to increase, precisely controlling their motion becomes more important. Guidance systems are increasingly used for controlling agricultural and environmental management equipment and operations such as road side spraying, road salting, and snow plowing where following a previously defined route is desirable. This allows more precise control of the vehicles than is typically realized than if the vehicle is steered by a human. Many rely upon furrow followers which mechanically detect whether the vehicle is moving parallel to a previously plowed plant furrow. However, these guidance systems are most effective in flat terrain and when detecting furrows plowed in a straight line. Additionally, many of these systems require factory installation and are too expensive or inconvenient to facilitate after market installation. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, a need exists for system which is suitable guiding mobile machines such as agricultural vehicles. While meeting the above stated need, it is also desirable that the guidance system is suitable for after market installation in those vehicles. Embodiments of the present invention recite system for controlling a mobile machine. In one embodiment the system comprises a position determining component for determining the geographic position of the mobile machine. The system further comprises a steering component for controlling the steering mechanism of the mobile machine in response to a message. The system further comprises a control component coupled with the position determining component and with the steering component. The control component generates a message to the steering component in response to receiving position data from the position determining component. | 20040714 | 20070306 | 20060119 | 94411.0 | G01C2126 | 0 | CHIN, GARY | METHOD AND SYSTEM FOR CONTROLLING A MOBILE MACHINE | UNDISCOUNTED | 0 | ACCEPTED | G01C | 2,004 |
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10,892,202 | ACCEPTED | Transmit channel policing system, device, and method | Systems and methods are provided for controlling transmit channel utilization in systems providing walkie-talkie-like communications to wireless devices. Parameters such as a maximum talk time and back off time are provided to each wireless device to control how long they can continuously occupy the talk channel, and to control how soon after releasing the talk channel they can again access the talk channel. | 1. A talk control element, for use with a network system adapted to deliver walkie-talkie-like communications capabilities between wireless devices, the network system allowing only one wireless device to occupy a talk channel at a given time, the talk control element being adapted to transmit at least one parameter to each wireless device which controls an amount of time each wireless device is allowed to continuously occupy a talk channel. 2. A talk control element according to claim 1 forming part of and in combination with the network system. 3. A talk control element according to claim 1 wherein the talk control element is external to the network system. 4. A network system according to claim 2 wherein the at least one parameter comprises a maximum talk time parameter for each wireless device representing a maximum amount of time the wireless device can continuously occupy the talk channel. 5. A network system according to claim 2 wherein the at least one parameter further comprises a back off time parameter to each wireless device representing a minimum time after releasing a talk channel before the wireless device can again request the talk channel. 6. A network system according to claim 4 wherein the at least one parameter comprises a back off time parameter for each wireless device representing a minimum time after releasing a talk channel before the wireless device can again request the talk channel. 7. A network system according to claim 2 adapted to send the parameters upon registration of the wireless device. 8. A network system according to claim 2 adapted to, for each wireless device, send the parameters upon registration of the wireless device only if a change to at least one of the parameters has occurred. 9. A network system according to claim 2 in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter. 10. A network system according to claim 4 in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; wherein each wireless device automatically releases the talk channel after expiry of a period of time represented by the maximum talk time parameter for the wireless device. 11. A network system according to claim 5 in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; wherein each wireless device automatically releases the talk channel after expiry of a period of time represented by the maximum talk time parameter; following release of the talk channel by a wireless device, the wireless device does not allow a request for the talk channel to be generated for a period of time represented by the back off time parameter for the wireless device. 12. A network system according to claim 6 in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; following release of the talk channel by a wireless device, the wireless device does not allow a request for the talk channel to be generated for a period of time represented by the back off time parameter for the wireless device. 13. A network system according to claim 2 wherein the network is implemented using at least one of PoC, IDEN, 1xRTT CDMA, UMTS, GSM/GPRS and TDMA. 14. A wireless device adapted to participate in a network delivered walkie-talkie-like communications session, the wireless device comprising: a talk processing element adapted to control amounts of time the wireless device is allowed to continuously occupy a talk channel for the session. 15. A wireless device according to claim 14 adapted to control amounts of time the wireless device is allowed to continuously occupy a talk channel for the session in accordance with at least one parameter received from the network. 16. A wireless device according to claim 14 adapted to automatically release the talk channel after continuously occupying the talk channel for a specified period of time. 17. A wireless device according to claim 14 adapted to prevent the generation of a request for the talk channel for a specified period of time following release of the talk channel by the wireless device. 18. A wireless device according to claim 16 adapted to prevent the generation of a request for the talk channel for a specified period of time following release of the talk channel by the wireless device. 19. A method comprising: providing each wireless device participating in a network-delivered walkie-talkie-like communications session with at least one parameter to control an amount of time each wireless device is allowed to continuously occupy a talk channel; each wireless device controlling access to the talk channel in accordance with the at least one parameter. 20. A method according to claim 19 wherein the at least one parameter comprises a maximum talk time and a back-off time. 21. A method according to claim 19 wherein the at least one parameter is transmitted to each wireless device upon registration of the device with the network. | FIELD OF THE INVENTION The invention relates to wireless communications systems and more particularly to policing of transmit channel possession in wireless communications systems providing half-duplex voice communications services. BACKGROUND OF THE INVENTION Communication systems are available which provide walkie-talkie-like functionality or similar half-duplex voice functionality which may take the form of PTT™ (push-to-talk™) over a dispatch service, PTT™ over cellular (PoC) services (part of the OMA standard), or otherwise. When referred to herein, walkie-talkie-like functionality and half-duplex voice functionality are to be taken generally to mean any voice communication functionality delivered via a network or networks which at any one time is capable of transmitting voice communication from a talking or transmitting party's device to a listening or receiving party's device, but does not simultaneously transmit voice communication from the receiving party's device to the talking party's device, while the talking party's device is transmitting voice to the receiving party's device. During an active PTT™ session or dispatch call session, only one user device (the “talker's” device) participating in the session may be designated as the transmitting or talking device at any one time. The communication can be one to one or one to many. A user device gains the role of transmitting device by requesting the talk/transmit channel from the network and by being granted the talk/transmit channel by the network. While a talker's device is in possession of the transmit channel (during a talk period), all of the other devices (listeners' devices) in the active dispatch call session are in listener mode and cannot transmit voice until the transmitting device requests the network to terminate the talk period and release the talk/transmit channel. Times during which the talk/transmit channel is not occupied are idle periods. In standard implementations of PTT™, the user interface of, for example, a wireless device, includes a “talk” button to allow the user to control the sending of requests to acquire and release the talk/transmit channel, these requests being sent over a logical control channel to the network. An example of a system providing PTT™ functionality as part of its dispatch services is the iDEN™ system of Motorola™. Other example systems which can provide such PTT™ services are 1xRTT CDMA, UMTS, GSM/GPRS, and TDMA. Push-to-talk™ service may be provided as an optional half-duplex service over existing network systems which also provide for full duplex communication, or may be provided as a service over network systems which provide only half-duplex communication. SUMMARY OF THE INVENTION According to one broad aspect, the invention provides a talk control element, for use with a network system adapted to deliver walkie-talkie-like communications capabilities between wireless devices, the network system allowing only one wireless device to occupy a talk channel at a given time, the talk control element being adapted to transmit at least one parameter to each wireless device which controls an amount of time each wireless device is allowed to continuously occupy a talk channel. In some embodiments, a talk control element forms part of and in combination with the network system. In some embodiments, the talk control element is external to the network system. In some embodiments, the at least one parameter comprises a maximum talk time parameter for each wireless device representing a maximum amount of time the wireless device can continuously occupy the talk channel. In some embodiments, the at least one parameter further comprises a back off time parameter to each wireless device representing a minimum time after releasing a talk channel before the wireless device can again request the talk channel. In some embodiments, the at least one parameter comprises a back off time parameter for each wireless device representing a minimum time after releasing a talk channel before the wireless device can again request the talk channel. In some embodiments, a network system is adapted to send the parameters upon registration of the wireless device. In some embodiments, a network system is adapted to, for each wireless device, send the parameters upon registration of the wireless device only if a change to at least one of the parameters has occurred. In some embodiments, a network system in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter. In some embodiments, a network system in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; wherein each wireless device automatically releases the talk channel after expiry of a period of time represented by the maximum talk time parameter for the wireless device. In some embodiments, a network in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; wherein each wireless device automatically releases the talk channel after expiry of a period of time represented by the maximum talk time parameter; following release of the talk channel by a wireless device, the wireless device does not allow a request for the talk channel to be generated for a period of time represented by the back off time parameter for the wireless device. In some embodiments, a network system in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; following release of the talk channel by a wireless device, the wireless device does not allow a request for the talk channel to be generated for a period of time represented by the back off time parameter for the wireless device. In some embodiments, the network is implemented using at least one of PoC, IDEN, 1xRTT CDMA, UMTS, GSM/GPRS and TDMA. According to another broad aspect, the invention provides a wireless device adapted to participate in a network delivered walkie-talkie-like communications session, the wireless device comprising: a talk processing element adapted to control amounts of time the wireless device is allowed to continuously occupy a talk channel for the session. In some embodiments, a wireless device is adapted to control amounts of time the wireless device is allowed to continuously occupy a talk channel for the session in accordance with at least one parameter received from the network. In some embodiments, a wireless device is adapted to automatically release the talk channel after continuously occupying the talk channel for a specified period of time. In some embodiments, a wireless device is adapted to prevent the generation of a request for the talk channel for a specified period of time following release of the talk channel by the wireless device. According to another broad aspect, the invention provides a method comprising: providing each wireless device participating in a network-delivered walkie-talkie-like communications session with at least one parameter to control an amount of time each wireless device is allowed to continuously occupy a talk channel; each wireless device controlling access to the talk channel in accordance with the at least one parameter. In some embodiments, the at least one parameter comprises a maximum talk time and a back-off time. In some embodiments, the at least one parameter is transmitted to each wireless device upon registration of the device with the network. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will now be described with reference to the attached drawings in which: FIG. 1A is a block diagram illustrating an example active PTT™ session of a group according to an example embodiment of the invention in which talk control is performed by the network providing the PTT session; FIG. 1B is a block diagram illustrating an active PTT™ session of a group according to an example embodiment of the invention in which talk control is performed external to the network providing the PTT session; FIG. 2 is a schematic diagram of an example implementation of a wireless device provided by an embodiment of the invention; FIG. 3 is a flow diagram illustrating the steps performed in one embodiment of the invention for transmit channel policing; FIG. 4 is a flow diagram illustrating the steps performed in another embodiment of the invention for transmit channel policing; FIG. 5 is a flow diagram illustrating the steps performed in an embodiment of the invention for transmit channel policing parameter provisioning; and FIG. 6 is a flow diagram illustrating the steps performed in another embodiment of the invention for transmit channel policing parameter provisioning. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the particular examples that follow, the walkie-talkie-like capabilities are assumed to be PTT capabilities. More generally, embodiments of the invention can be employed with any system providing network delivered walkie-talkie-like capabilities and are not limited to PTT™ capabilities of the examples. A network capable of delivering this will be referred to as a “dispatch network”, even though such a network may also deliver non-dispatch functionality. Users on the receiving end of a push-to-talk™ session held on known systems have no way of communicating to any other user in a group while a user of a transmitting device is transmitting, since the talk/transmit channel is occupied by the transmitting device until released. As such, prior to the present invention, there was no mechanism to prevent a user from indefinitely keeping possession of the talk/transmit channel. Embodiments of the present invention attempt to mitigate the potential for abuse and the resulting inconvenience due to a user's possessing the transmit/talk channel indefinitely, or repeatedly taking control of the transmit channel without allowing other users participating in the call a chance to speak. In accordance with the preferred embodiments discussed below, methods, systems, and novel user devices, may be used to automatically provide policing of PTT™ transmit channel possession duration and transmit channel requesting frequency. In preferred embodiments different subscribers may have different rules governing the policing of their PTT™ transmissions based on, for example, the Service Level Agreement(SLA)/policy set for the subscriber. Referring now to FIG. 1A, an example of a transmit channel policing method according to an embodiment of the invention will now be described in the context of an active dispatch call session for a PTT™ group of wireless mobile devices in a half-duplex dispatch system. A communications system, generally indicated by reference numeral 11, which is a modified iDEN™ system, is shown having a PTT™ group (indicated generally by reference numeral 10) consisting of a group of mobile devices participating in an active PTT™ session while a transmit channel is possessed, along with the rest of a dispatch network 39. The group 10 contains a single mobile device 20 in THD (transmitting in half-duplex) mode which is in talk/transmit mode and in possession of the transmit channel, and a set (only four shown) of devices 30 in RHD (receiving in half-duplex) mode which are in listening mode. It should be understood that transmit channel policing is equally applicable to embodiments in which the dispatch call session only involves two devices (a 1-to-1 session) or which involves more than two devices (a 1-to-many session). To simplify this description, a device in THD mode or RHD mode will be referred to as a THD device or an RHD device respectively. However it is to be understood these are temporary designations for the particular mode of operation of the device at any particular time. During the active session, the users of the RHD devices 30 are referred to as listeners, while the user of the THD device 20 is referred to as the talker. Each device of the specific embodiment shown in FIG. 1A is capable of functioning either as a THD device or an RHD device, depending upon which device is in talk/transmit mode and which devices are in listening mode during any particular active session. Upon receipt of a request from a wireless device for the talk channel, if the system grants the device the talk channel, then the device enters THD mode. The establishment of the wireless links between devices of the users, the routing of voice data packets, and the duplication of voice data packets to each of the devices in listening mode are specific to each implementation of a PTT™ or similar half-duplex voice communication system. These functions are represented abstractly by links 25 which represent all of the system components which are part of the network 39 which are necessary to communicate the voice data sent by the THD device 20 to all of the RHD devices 30 and in general support the functions of the active session. The details of these links are not relevant here. During the active session, the THD device 20 possesses the talk/transmit channel. A user can release the channel, for example, by releasing the talk button causing the wireless device 20 to initiate a request for release of the channel or to terminate the call, or using any appropriate interface provided on the device. Within the dispatch network 39 is a dispatch application processor (DAP) 130 which is the processing entity responsible for the overall coordination and control of dispatch services in the iDEN™ system. The DAP 130 is coupled to a dispatch home location register (D-HLR) 120 which is a repository of data for dispatch calling identification and services. In some implementations the D-HLR 120 is resident on the DAP 130. The DAP 130 is coupled to a metro packet switch (MPS) 140 which is in turn coupled to a digital access cross connect switch (DACS) 150. The DACS 150 in turn is coupled to an enhanced base transceiver station (EBTS) 160. The EBTS 160 communicates with user devices over communication channel 8 over the air (OTA). Channel 8 may be outbound and inbound half-duplex voice communication channels (not shown), a control channel, and/or other existing channels (not shown). Various embodiments discussed below may use the DCCH (dedicated control channel) as the communication channel 8 to send and receive messages associated with transmit channel policing. In the course of providing coordination and control of dispatch calls, the DAP 130 may retrieve information from the D-HLR 120 regarding the various services and/or identifications including information pertaining to the particular service level, or policy set which determines the manner in which any particular mobile device is to be policed with respect to the transmit channel policing. In the course of communicating with the user device 20, the DAP 130 sends messages via the MPS 140, the DACS 150, and the EBTS 160 in order to interact with the user device 20. The DAP 130 also has message generating and processing 132 which is adapted to send information pertaining to transmit channel policing including a maximum talk time, and a back-off time as discussed below. In a preferred embodiment, the message generation and processing 132 is implemented as a change to software already implemented on the DAP 130, but it may be implemented as separate software, hardware, firmware or a combination of these types of functionality. FIG. 1A shows a very specific example of network functionality which provides transmit channel policing services. The arrangement of FIG. 1A is particularly suitable for iDEN™ applications. It is to be clearly understood that other network side implementations may be employed for delivering the transmit channel policing methods described herein. These other implementations may be specific to iDEN™ or to other dispatch service implementations. The dispatch service may, of course, include additional system components not shown in FIG. 1A. According to a preferred embodiment, during an active session the listener's devices 30 are no longer at the mercy of the THD device 20 in that the transmit/talk channel is no longer entirely under the control of the user of the THD device 20. As will be described below, parameters related to transmit channel policing which are updated or reassigned within the network may be communicated to the THD device 20 upon the device registering with the network, and/or at other times. Another embodiment of the invention is illustrated in FIG. 1B. In this embodiment, a NAW (network adapted to deliver walkie-talkie like functionality) 50 and a plurality of wireless devices 52,54 (only two shown in the illustrated example). A talk control element 56 has the parameters that are used to control talk channel usage. The talk control element 56 sends these parameters to the wireless devices. In some embodiments, the talk control element 56 is part of the NAW 50. In another embodiment, the talk control element 56 is external to the NAW 50. In the event the talk control element 56 is external to the NAW 50, it might be connected to the dispatch network through a data gateway. For example, a given corporate client may implement the talk channel policing independent of the dispatch network by providing their own talk control element 56. In such an embodiment, the parameters are sent from the talk control element 56 independent of other messages used to implement the walkie-talkie-like functionality, for example by sending packet data. The talk control element may be implemented in hardware, software, firmware to name a few examples or any combination of such elements, and may be centrally located or distributed. For the embodiment of FIG. 1A, the talk control element 56 is implemented as part of the network, and uses the D-HLR to store the parameters. Referring to FIG. 2, an example implementation of a PTT™ capable wireless device 300 provided by an embodiment of the invention will now be described. It is to be clearly understood that this is but one example of a wireless device which can be employed in embodiments of the invention allowing transmit channel policing. It is also to be clearly understood that many other features will typically be included in an actual wireless device. These features are not shown in the interest of clarity. In the embodiment depicted in FIG. 2, the wireless device 300 has a talk request interface in the form of a keypad 312, and has a touchscreen 340. Other embodiments could include any other suitable input/output element(s). The talk request interface is coupled to a processing element 320. The processing element 320 is coupled to message transmission element 332. The message transmission element 332 may share resources with a message reception element 334. The message reception element 334 is coupled to the processing element 320. Elements 332,334 preferably form part of standard reception and transmission capabilities on the wireless device. The processing element 320 represents any suitable processing capabilities implemented within the wireless device to handle the operation of the algorithms for policing the transmit channel. This element may be implemented as one or a combination of hardware, software, firmware. In a preferred embodiment, the processing element 320 is included as an addition to software capabilities already provided on an existing wireless device. In operation, the wireless device 300 depicted in FIG. 2 is able to operate in a network providing walkie-talkie-like half duplex communications capabilities in THD mode and RHD mode. The device 300 is capable of initiating a group session and requesting the transmit channel from the network, upon initiation by the user. In the embodiment of FIG. 2, this initiation is effected by the pressing and holding down of a talk button within the keypad 312. The device does not enter THD mode until the system grants the transmit channel. Processing element 320 performs transmit channel policing functions by obtaining any necessary data from storage 322, and commencing a timer function from the time the device enters THD mode. The transmit channel policing is executed preferably in accordance with the method described below with reference to FIGS. 3 and 4, or similar methods. The policing functions serve to limit the time that the device will possess the transmit channel. These functions also serve to restrain the device from obtaining the transmit channel again until a certain amount of time has passed after the talk button is released by the user. FIG. 2 shows a very specific implementation for a user device capable of implementing the transmit channel policing methods provided by embodiments of the invention. It is to be clearly understood that the particular arrangement of components of FIG. 2 is only one example. The user device 300 may of course include additional components not shown in FIG. 2. The same functionality may be delivered with a different breakdown of components. Referring now to FIGS. 3 and 4, an example of transmit channel policing according to an embodiment of the invention will now be described in the context of an active dispatch call session for a group of wireless devices in a half-duplex group call. Each wireless device may for example be as described with reference to FIG. 2 above, but is not limited thereto. In the communications system, the THD device which is to be policed, first would have had to be powered up and registered on the network at step 400. In step 401, during or following registration, the system sends parameters to control transmit channel utilization. In the example that follows this is a maximum talk time (MTT) which is then stored in the data store. More generally, the device receives the parameter(s) and starts to operate in accordance with the parameter(s). In another embodiment, the parameters are not sent over the air, but rather are configured during manufacture or otherwise prior to deployment. Transmit channel policing processing is initialized at step 402 with the loading of a maximum talk time (MTT) parameter. Preferably, the MTT, or a parameter representing the MTT, is stored by the network, for example in D-HLR 120 for the network of FIG. 1A. This is downloaded upon power up or registration of the device. In another embodiment, all devices are configured with a default MTT which can then be used without requiring any change to the air interface. The transmit channel policing processing remains idle until the user device receives input initiating THD mode at step 403. After being granted the transmit channel, the user device thereafter begins to operate in THD mode at step 404.If the device is still in THD mode upon expiry of the MTT, the device will automatically release the channel. Any appropriate mechanism for timing the THD duration can be employed. A specific example has been included in FIG. 3. In this example, transmit channel policing processing starts a timer function at step 406 to keep track of the passage of an MTT duration. If an interrupt is received as indicated at step 410, for example by as a result of the user releasing the talk button or the call ending, the transmit channel is released as indicated at step 414. Alternatively, if the MTT has expired (yes path 412), then the transmit channel is also released at step 414. Thus at the end of the method steps, the transmit channel will be available to other users. At the latest this will occur a duration of MTT after the user started transmitting. In a preferred embodiment, a plurality of different levels of service or policy sets are defined, each with a respective MTT that may or may not be the same as that associated with others levels of service. The maximum talk time of a particular wireless device therefor is set based upon the level of service associated with the wireless device. Example values of MTT include but are not limited to seconds, minutes, and indefinite. A setting of indefinite could be policy based and assigned to important users or users responsible for critical operations who should be allowed to possess the transmit channel until they see fit to release it. Other possible times for MTT may be associated with for example Gold, Silver, and Bronze service level agreements. In the case where the MTT is set such that the device may possess the transmit channel indefinitely, steps 410 and 412 will be repeated until the user releases the talk button, at which point an interrupt will be assessed at step 412 and the transmit channel is released. Alternatively, no timing of the THD mode needs to take place in such a device. Referring to FIG. 4, another example of transmit channel policing provided by another embodiment of the invention will now be described. As with the steps performed in the embodiment depicted in FIG. 3, the THD device of FIG. 4 which is to be policed, first would have had to be powered up and registered on the network at step 450. The parameters are sent to the user devices at step 451. Transmit channel policing processing initializes at step 452 with the loading of a maximum talk time (MTT) parameter and a back off time (BOT). For the duration of the BOT, after a user releases a talk button, the user cannot request the transmit channel by again pressing the talk button. In this way a user is prevented from requiring the transmit channel before anyone else gets a chance to request the transmit channel. A number of ways of preventing a particular user from accessing the channel following release may be implemented. A particular example is given below, but different methods may be used. The transmit channel policing processing remains idle until the user device receives input initiating THD mode at step 453. The transmit channel policing processing checks to see if the BOT timer has expired (either because it never started, or because a prior started BOT timer is running) at step 455. This would be the case if a user pressed the talk button within the duration of BOT, after previously releasing the channel. If the BOT timer has not expired, the process proceeds back to prior to step 453 when the device detected user input. In the case where the BOT timer is expired, the device is allowed to transmit the request for THD mode, and once the transmit channel is granted, the device will enter THD mode. Steps 404, 406, 410, 412, 414 of the method is the same as those described already with reference to FIG. 3. At step 460, following release of the transmission channel the BOT timer is started at step 460. In a preferred embodiment, for each of the plurality of different levels of service or policy sets is a BOT which may or may not be the same as that associated with other levels of service. The back off time of a particular wireless device therefor is set based upon the level of service associated with the wireless device. Example values of BOT include but are not limited to seconds, minutes, and zero. A set value of zero could be policy based and assigned to important users or users responsible for critical operations, so that they can possess the transmit channel as soon as they wish after having released the talk button. The other possible times for BOT may be associated with for example Gold, Silver, and Bronze SLAs (service level agreements) in which less BOT is assigned to some levels than that which is assigned to others. In the case where the BOT to zero, steps 453 would always return a false as the BOT timer would never be started for that particular device under that SLA. Hence the device would simply proceed to step 454 and enter THD mode. It should be understood that in the embodiments discussed above other processes may be running on the user device and other steps may be inserted into the methods described without changing the nature of the example embodiment. In some embodiments, the method, system, and device are adapted to provide peripheral support for wired devices to participate in a wireless call via a network interworking function, so that although the devices are not within the wireless network, they appear as though they are, and are able to participate therein. Hence, according to this embodiment, not all of the devices in a PTT™ group are wireless, and transmit channel messaging occurs in an analogous manner to that described above in PTT™ groups where one or more of the devices is a stationary or otherwise non-wireless wired device. Hence, a wireless PTT™ session may have wired or landline based devices participating in the PTT™ session in accordance with the embodiments, adapted to police the transmit channel. Some embodiments of the invention provide for the provisioning of the information such as the MTT and the BOT for storage in the wireless device. Two such examples are illustrated in FIGS. 5, and 6. Referring to FIG. 5, a user device is provisioned with the MTT and BOT parameters whenever the network data for that user changes, or when the device is first initialized at step 500, upon power up of the user device. After the user's device powers up and registers at step 502, the network sends MTT and BOT parameters to the user device in step 504. The transfer of this information may occur within a registration accept message through a new control channel, an existing control channel, or through a traffic channel. In step 506 the user device stores MTT and BOT parameters. Referring to FIG. 6, a user device is provisioned with the MTT and BOT parameters whenever the network data for that user changes, or when the device is first initialized at step 600. Even if the user device is idle, the network sends MTT and BOT parameters to the user device in step 604. These values are transmitted over a channel from the network to the user device. This can be transmitted on a separate control channel, or on a traffic channel. In an embodiment implemented in the iDEN™ system of Motorola™, a preferred logical control channel used to send the MTT and BOT is the data link layer sometimes referred to as layer 2. The MTT and BOT could be sent over the L2 control channel, such as the dedicated control channel (DCCH) or packet channel, or an associated control channel (ACCH). In step 606 the user device stores MTT and BOT parameters in the data store. Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | <SOH> BACKGROUND OF THE INVENTION <EOH>Communication systems are available which provide walkie-talkie-like functionality or similar half-duplex voice functionality which may take the form of PTT™ (push-to-talk™) over a dispatch service, PTT™ over cellular (PoC) services (part of the OMA standard), or otherwise. When referred to herein, walkie-talkie-like functionality and half-duplex voice functionality are to be taken generally to mean any voice communication functionality delivered via a network or networks which at any one time is capable of transmitting voice communication from a talking or transmitting party's device to a listening or receiving party's device, but does not simultaneously transmit voice communication from the receiving party's device to the talking party's device, while the talking party's device is transmitting voice to the receiving party's device. During an active PTT™ session or dispatch call session, only one user device (the “talker's” device) participating in the session may be designated as the transmitting or talking device at any one time. The communication can be one to one or one to many. A user device gains the role of transmitting device by requesting the talk/transmit channel from the network and by being granted the talk/transmit channel by the network. While a talker's device is in possession of the transmit channel (during a talk period), all of the other devices (listeners' devices) in the active dispatch call session are in listener mode and cannot transmit voice until the transmitting device requests the network to terminate the talk period and release the talk/transmit channel. Times during which the talk/transmit channel is not occupied are idle periods. In standard implementations of PTT™, the user interface of, for example, a wireless device, includes a “talk” button to allow the user to control the sending of requests to acquire and release the talk/transmit channel, these requests being sent over a logical control channel to the network. An example of a system providing PTT™ functionality as part of its dispatch services is the iDEN™ system of Motorola™. Other example systems which can provide such PTT™ services are 1xRTT CDMA, UMTS, GSM/GPRS, and TDMA. Push-to-talk™ service may be provided as an optional half-duplex service over existing network systems which also provide for full duplex communication, or may be provided as a service over network systems which provide only half-duplex communication. | <SOH> SUMMARY OF THE INVENTION <EOH>According to one broad aspect, the invention provides a talk control element, for use with a network system adapted to deliver walkie-talkie-like communications capabilities between wireless devices, the network system allowing only one wireless device to occupy a talk channel at a given time, the talk control element being adapted to transmit at least one parameter to each wireless device which controls an amount of time each wireless device is allowed to continuously occupy a talk channel. In some embodiments, a talk control element forms part of and in combination with the network system. In some embodiments, the talk control element is external to the network system. In some embodiments, the at least one parameter comprises a maximum talk time parameter for each wireless device representing a maximum amount of time the wireless device can continuously occupy the talk channel. In some embodiments, the at least one parameter further comprises a back off time parameter to each wireless device representing a minimum time after releasing a talk channel before the wireless device can again request the talk channel. In some embodiments, the at least one parameter comprises a back off time parameter for each wireless device representing a minimum time after releasing a talk channel before the wireless device can again request the talk channel. In some embodiments, a network system is adapted to send the parameters upon registration of the wireless device. In some embodiments, a network system is adapted to, for each wireless device, send the parameters upon registration of the wireless device only if a change to at least one of the parameters has occurred. In some embodiments, a network system in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter. In some embodiments, a network system in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; wherein each wireless device automatically releases the talk channel after expiry of a period of time represented by the maximum talk time parameter for the wireless device. In some embodiments, a network in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; wherein each wireless device automatically releases the talk channel after expiry of a period of time represented by the maximum talk time parameter; following release of the talk channel by a wireless device, the wireless device does not allow a request for the talk channel to be generated for a period of time represented by the back off time parameter for the wireless device. In some embodiments, a network system in combination with a plurality of said wireless devices, each wireless device comprising a talk processing element for processing the at least one parameter, and allowing requests for the talk channel to be generated in accordance with the at least one parameter; following release of the talk channel by a wireless device, the wireless device does not allow a request for the talk channel to be generated for a period of time represented by the back off time parameter for the wireless device. In some embodiments, the network is implemented using at least one of PoC, IDEN, 1xRTT CDMA, UMTS, GSM/GPRS and TDMA. According to another broad aspect, the invention provides a wireless device adapted to participate in a network delivered walkie-talkie-like communications session, the wireless device comprising: a talk processing element adapted to control amounts of time the wireless device is allowed to continuously occupy a talk channel for the session. In some embodiments, a wireless device is adapted to control amounts of time the wireless device is allowed to continuously occupy a talk channel for the session in accordance with at least one parameter received from the network. In some embodiments, a wireless device is adapted to automatically release the talk channel after continuously occupying the talk channel for a specified period of time. In some embodiments, a wireless device is adapted to prevent the generation of a request for the talk channel for a specified period of time following release of the talk channel by the wireless device. According to another broad aspect, the invention provides a method comprising: providing each wireless device participating in a network-delivered walkie-talkie-like communications session with at least one parameter to control an amount of time each wireless device is allowed to continuously occupy a talk channel; each wireless device controlling access to the talk channel in accordance with the at least one parameter. In some embodiments, the at least one parameter comprises a maximum talk time and a back-off time. In some embodiments, the at least one parameter is transmitted to each wireless device upon registration of the device with the network. | 20040716 | 20100907 | 20060119 | 93349.0 | H04B700 | 0 | GONZALES, APRIL GUZMAN | TRANSMIT CHANNEL POLICING SYSTEM, DEVICE, AND METHOD | UNDISCOUNTED | 0 | ACCEPTED | H04B | 2,004 |
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10,892,510 | ACCEPTED | Programmable wallbox dimmer | A programmable wallbox dimmer is disclosed. Upon entering a programming mode, the dimmer presents a main menu from which the user may select one or more features to program. The user may scroll through a list of programmable features by actuating the dimmer's raise/lower intensity actuator. The user may select a highlighted feature by actuating the dimmer's control switch. The dimmer may enter a value selection mode that is associated with the selected feature. In the value selection mode, the user may scroll through a list of features that define the selected feature by actuating the dimmer's raise/lower intensity actuator. The user may select a value for the selected feature. The selected value may be stored in the dimmer's memory. | 1. A lighting control device for controlling a light intensity level of a lamp, said lighting control device comprising: an intensity level switch; a control switch; an air gap switch; and a microcontroller operatively coupled to the intensity level switch, the control switch, and the air gap switch, wherein, in a normal operational mode, the intensity level switch enables a user to select a desired light intensity level between a minimum intensity level and a maximum intensity level, the control switch enables the user to toggle the lamp between an on state and an off state, and the air gap switch enables the user to interrupt power supplied to the microcontroller and to the lamp, and wherein the microcontroller is adapted to cause the lighting control device to enter a programming mode after detecting that the control switch had been actuated when the microcontroller was being powered up and that the control switch has remained actuated for at least a prescribed period of time after the microcontroller was powered up. 2. The lighting control device of claim 1, wherein the programming mode includes a feature selection mode wherein the user may select a programmable feature of the lighting control device. 3. The lighting control device of claim 2, wherein the user may select the programmable feature from among a plurality of programmable features. 4. The lighting control device of claim 2, further comprising a programmable feature indicator associated with the programmable feature. 5. The lighting control device of claim 3, further comprising a respective programmable feature indicator associated with each of the plurality of programmable features. 6. The lighting control device of claim 2, wherein the programming mode comprises a value selection mode wherein the user may select a programmable feature value associated with a selected programmable feature. 7. The lighting control device of claim 6, wherein the user may select the programmable feature value from among a plurality of programmable feature values. 8. The lighting control device of claim 6, further comprising a programmable feature value indicator associated with the programmable feature value. 9. The lighting control device of claim 7, further comprising a respective programmable feature value indicator associated with each of the plurality of programmable feature values. 10. The lighting control device of claim 8, further comprising a programmable feature indicator associated with the programmable feature. 11. The lighting control device of claim 10, wherein the programmable feature indicator blinks at a first blink rate. 12. The lighting control device of claim 11, wherein the programmable feature value indicator blinks at a second blink rate that is different from the first blink rate. 13. The lighting control device of claim 12, wherein the first blink rate is slower than the second blink rate. 14. The lighting control device of claim 5, wherein each of the programmable feature indicators includes a respective light source, said light sources are disposed in a sequence, and each of said light sources represents a respective one of the plurality of programmable features. 15. The lighting control device of claim 9, wherein each of the programmable feature value indicators includes a respective light source, said light sources are disposed in a sequence, and each of said light sources represents a respective one of the plurality of programmable feature values. 16. The lighting control device of claim 5, wherein, in the feature selection mode, the microcontroller causes a light source associated with a feature to be selected upon actuation of the control switch to blink at a first rate. 17. The lighting control device of claim 9, wherein, in the feature selection mode, the microcontroller causes a light source associated with a feature to be selected upon actuation of the control switch to blink at a first rate. 18. The lighting control device of claim 17, wherein, in the value selection mode, the microcontroller causes a light source associated with a value to be selected upon actuation of the control switch to blink at a second rate that is different from the first rate. 19. The lighting control device of claim 6, wherein the microcontroller causes a selected programmable feature value to be stored in memory. 20. The lighting control device of claim 7, wherein the microcontroller causes a selected programmable feature value to be stored in memory. 21. The lighting control device of claim 3, wherein actuation of the light intensity level switch enables for subsequent selection a desired one of the plurality of programmable features. 22. The lighting control device of claim 7, wherein actuation of the light intensity level switch enables for subsequent selection a desired one of the plurality of programmable feature values. 23. The lighting control device of claim 1, wherein the microcontroller is adapted to cause the lighting control device to return to the normal operational mode from the programming mode if none of the intensity level switch, the control switch, and the air gap switch has been actuated for at least a prescribed timeout period. 24. The lighting control device of claim 1, wherein the microcontroller is adapted to cause the lighting control device to return to the normal operational mode from the programming mode if, while in the programming mode, the microcontroller detects that the control switch has been actuated for at least a prescribed period of time. 25. A wallbox dimmer for controlling a light intensity level of a lamp, the wallbox dimmer having a normal operational mode and a programming mode, the wallbox dimmer comprising: an intensity level switch; and a microcontroller operatively coupled to the intensity level switch, wherein, in the normal operational mode, the microcontroller causes the light intensity level of the lamp to vary in response to an actuation of the intensity level switch, and, in the programming mode, the microcontroller enables a user to program any of a plurality of programmable features provided by the wallbox dimmer. 26. The wallbox dimmer of claim 25, wherein, in the programming mode, the microcontroller causes the wallbox dimmer to vary between a feature selection mode and a value selection mode in response to an actuation of the control switch. 27. The wallbox dimmer of claim 26, wherein the feature selection mode enables user-selection of a desired one of said plurality of programmable features. 28. The wallbox dimmer of claim 26, wherein the value selection mode enables user-selection of a desired one of a plurality of programmable feature values associated with a desired one of said plurality of programmable features. 29. A wallbox dimmer for controlling a light intensity level of a lamp, the wallbox dimmer having a normal operational mode and a programming mode, the wallbox dimmer comprising: a control switch; and a microcontroller operatively coupled to the control switch, wherein, in the normal operational mode, the microcontroller causes the lamp to toggle between an off state and an on state in response to an actuation of the control switch, and, in the programming mode, the microcontroller enables the user to program any of a plurality of programmable features provided by the wallbox dimmer. 30. The wallbox dimmer of claim 29, wherein, in the programming mode, the microcontroller causes the wallbox dimmer to vary between a feature selection mode and a value selection mode in response to an actuation of the control switch. 31. The wallbox dimmer of claim 30, wherein the feature selection mode enables user-selection of a desired one of said plurality of programmable features. 32. The wallbox dimmer of claim 30, wherein the value selection mode enables user-selection of a desired one of a plurality of programmable feature values associated with a desired one of said plurality of programmable features. 33. A wallbox dimmer for controlling a light intensity level of a lamp, the wallbox dimmer having a normal operational mode and a programming mode, the wallbox dimmer comprising: an intensity level display; and a microcontroller operatively coupled to the intensity level display, wherein, in the normal operational mode, the microcontroller causes the intensity level display to provide a user-perceptible indication representative of a current intensity level of the lamp, and, in the programming mode, the microcontroller enables a user to program any of a plurality of programmable features provided by the wallbox dimmer. 34. The wallbox dimmer of claim 33, wherein, in the programming mode, the microcontroller causes the intensity level display to provide a user-perceptible indication representative of one of said plurality of programmable features. 35. The wallbox dimmer of claim 34, wherein the intensity level display comprises a light source associated with said one of said plurality of programmable features and the microcontroller causes the light source to blink. 36. The wallbox dimmer of claim 33, wherein, in the programming mode, the microcontroller causes the intensity level display to provide a user-perceptible indication representative of a programmable feature value associated with one of said plurality of programmable features. 37. The wallbox dimmer of claim 36, wherein the intensity level display comprises a light source associated with the programmable feature value and the microcontroller causes the light source to blink. 38. A lighting control device for controlling a light intensity level of a lamp, said lighting control device having a normal operational mode and a programming mode, said lighting control device comprising: an intensity level switch; a control switch; and a microcontroller operatively coupled to the intensity level switch and the control switch, wherein, in the normal operational mode, the microcontroller causes the light intensity level of the lamp to vary in response to an actuation of the intensity level switch, and the lamp to toggle between an off state and an on state in response to an actuation of the control switch, and, in the programming mode, the microcontroller is adapted to cause the wallbox dimmer to enter a feature selection mode wherein a user is enabled to select a programmable feature provided by the wallbox dimmer from among a plurality of programmable features, and to enter a value selection mode wherein the user is enabled to select a programmable feature value associated with a selected one of the plurality of programmable features. 39. A method for programming a wallbox dimmer, said wallbox dimmer having an actuator for generating control signals in response to an input from a user and a microcontroller responsive to the control signals, the method comprising: detecting that the actuator is being actuated as the microcontroller is being powered-up, and in response to detecting that the actuator is being actuated as the microcontroller is being powered-up, entering a programming mode wherein the user is enabled to program any of a plurality of features provided by the wallbox dimmer. 40. The method of claim 39, wherein the wallbox dimmer further comprises an air gap switch, the method further comprising: initiating power-up of the microcontroller by opening and then closing the air gap switch. 41. The method of claim 39, wherein detecting that the actuator is being actuated further comprises: detecting that the actuator has been actuated for a predetermined period of time after power-up of the microcontroller. | FIELD OF THE INVENTION Generally, the invention relates to lighting control devices. More particularly, the invention relates to programmable wallbox dimmers. BACKGROUND OF THE INVENTION FIG. 1 depicts a typical dimmer circuit 100 comprising a source of electrical energy or power supply 112, a dimmer 114, and a lighting load 116. The lighting load 116 may be a lamp set comprising one or more lamps adapted to be connected between the hot and neutral terminals of a standard source of electrical energy. The lamp set may include one or more incandescent lamps and/or other lighting loads such as electronic low voltage (ELV) or magnetic low voltage (MLV) loads, for example. The power supply 112 supplies an electrical waveform to the dimmer 114. The dimmer regulates the delivery of electrical energy from the power supply 112 to the lighting load 116. The dimmer 114 may include a controllably conductive device 118 and a control circuit 120. The controllably conductive device 118 may include an input 122 adapted to be coupled to the power supply 112, an output 124 adapted to be coupled to the lighting load 116, and a control input 126. The control circuit 120 may have an input 128 coupled to the input 122 of the controllably conductive device 118 and an output 130 coupled to the control input 126 of the controllably conductive device 118. A typical, AC, phase-control dimmer regulates the amount of energy supplied to the lighting load 116 by conducting for some portion of each half-cycle of the AC waveform, and not conducting for the remainder of the half-cycle. Because the dimmer 114 is in series with the lighting load 116, the longer the dimmer 114 conducts, the more energy will be delivered to the lighting load 116. Where the lighting load 116 is a lamp set, the more energy delivered to the lighting load 116, the greater the light intensity level of the lamp set. In a typical dimming scenario, a user may adjust a control to set the light intensity level of the lamp set to a desired light intensity level. The portion of each half-cycle for which the dimmer conducts is based on the selected light intensity level. The controllably conductive device 118 may include a solid state switching device, which may include one or more triacs, which may be thyristors or similar control devices. Conventional light dimming circuits typically use triacs to control the conduction of line current through a load, allowing a predetermined conduction time, and control the average electrical power to the light. One technique for controlling the average electrical power is forward phase control. In forward phase control, a switching device, which may include a triac, for example, is turned on at some point within each AC line voltage half cycle and remains on until the next current zero crossing. Forward phase control is often used to control energy to a resistive or inductive load, which may include, for example, a magnetic lighting transformer. Because a triac device can only be selectively turned on, a power-switching device, such as a field effect transistor (FET), a MOSFET (metal oxide semiconductor FET), or an insulated gate bipolar transistor (IGBT), for example, may be used for each half cycle of AC line input when turn-off phase is to be selectable. In reverse phase control, the switch is turned on at a voltage zero-crossing of the AC line voltage and turned off at some point within each half cycle of the AC line current. A zero-crossing is defined as the time at which the voltage equals zero at the beginning of each half-cycle. Reverse phase control is often used to control energy to a capacitive load, which may include for example, an electronic transformer connected low voltage lamp. The switching device may have a control or “gate” input 126 that is connected to a gate drive circuit, such as an FET drive circuit, for example. Control inputs on the gate input render the switching device conductive or non-conductive, which in turn controls the energy supplied to the load. FET drive circuitry typically provides control inputs to the switching device in response to command signals from a microcontroller. FET protection circuitry may also be provided. Such circuitry is well known and need not be described herein. The microcontroller may be any processing device such as a programmable logic device (PLD), a microprocessor, or an application specific integrated circuit (ASIC), for example. Power to the microcontroller may be supplied by a power supply. A memory, such as an EEPROM, for example, may also be provided. Inputs to the microcontroller may be received from a zero-crossing detector. The zero-crossing detector determines the zero-crossing points of the input waveform from the power supply 112. The microcontroller sets up gate control signals to operate the switching device to provide voltage from the power supply 112 to the load 116 at predetermined times relative to the zero-crossing points of the waveform. The zero-crossing detector may be a conventional zero-crossing detector, and need not be described here in further detail. In addition, the timing of transition firing pulses relative to the zero crossings of the waveform is also known, and need not be described further. FIGS. 2A and 2B depict an example lighting control device 114 that may be programmable in accordance with the invention. As shown, the lighting control device 114 may include a faceplate 12, a bezel 13, an intensity selection actuator 14 for selecting a desired level of light intensity of a lighting load 16 controlled by the lighting control device, a control switch actuator 16, and an air gap actuator 17. Faceplate 12 need not be limited to any specific form, and is preferably of a type adapted to be mounted to a conventional wall box commonly used in the installation of lighting control devices. Likewise, bezel 13 and actuators 14, 16, and 17 are not limited to any specific form, and may be of any suitable design that permits manual actuation by a user. Actuation of the upper portion 14a of actuator 14 increases or raises the light intensity of lighting load 116, while actuation of lower portion 14b of actuator 14 decreases or lowers the light intensity. Actuator 14 may control a rocker switch, two separate push switches, or the like. Actuator 16 may control a push switch, though actuator 16 may be a touch-sensitive membrane or any other suitable type of actuator. Actuators 14 and 16 may be linked to the corresponding switches in any convenient manner. The switches controlled by actuators 14 and 16 may be directly wired into the control circuitry to be described below, or may be linked by an extended wired link, infrared link, radio frequency link, power line carrier link, or otherwise to the control circuitry. Air gap actuator 17 is provided in order to open an air gap switch in the lighting control device 114. The air gap switch disconnects the power supply 112 from the controllably conductive device 118, the control circuit 130, and the lighting load 116. The air gap switch is opened by pulling the air gap actuator 17 away from the faceplate 12 of the lighting control device 114. Lighting control device 114 may also include an intensity level indicator in the form of a plurality of light sources 18. Light sources 18 may be light-emitting diodes (LEDs), for example, or the like. Light sources 18 may occasionally be referred to herein as LEDs, but it should be understood that such a reference is for ease of describing the invention and in not intended to limit the invention to any particular type of light source. Light sources 18 may be arranged in an array (such as a linear array as shown) representative of a range of light intensity levels of the lighting load being controlled. The intensity levels of the lighting load may range from a minimum intensity level, which is preferably the lowest visible intensity, but which may be zero, or “full off,” to a maximum intensity level, which is typically “full on.” Light intensity level is typically expressed as a percent of full intensity. Thus, when the lighting load is on, light intensity level may range from 1% to 100%. By illuminating a selected one of light sources 18 depending upon light intensity level, the position of the illuminated light source within the array may provide a visual indication of the light intensity relative to the range when the lighting load being controlled is on. For example, seven LEDs are illustrated in FIGS. 2A and 2B. Illuminating the uppermost LED in the array may indicate that the light intensity level is at or near maximum. Illuminating the center LED may indicate that the light intensity level is at about the midpoint of the range. Any convenient number of light sources 18 may be used, and it should be understood that a larger number of light sources in the array will yield a commensurately finer gradation between intensity levels within the range. When the lighting load 116 being controlled is off, the LED representative of the intensity level at which the lighting load will turn on to may be illuminated at a relatively high illumination level, while the remaining light sources may be illuminated at a relatively low level of illumination. This enables the light source array to be more readily perceived by the eye in a darkened environment, which assists a user in locating the lighting control device 114 in a dark room, for example, in order to actuate the lighting control device 114 to control the lights in the room. Still, sufficient contrast may be provided between the level-indicating LED and the remaining LEDs to enable a user to perceive the relative intensity level at a glance. Lighting control device 114 may include a standard back box 20 having a plurality of high voltage screw terminal connections 22H, 22N, 22D that may be connections for hot, neutral, and dimmed hot, respectively. Such lighting control devices typically provide certain features such as, for example, protected preset, fading, and the like. Some such lighting control devices may enable a user to set a value associated with a feature the lighting control device provides. For example, lighting control devices are known that enable a user to set a light intensity value associated with the “protected preset” feature (see, for example, U.S. Pat. No. 6,169,377, which describes a lighting control unit having the protected or “locked” preset feature). Protected preset is a feature that allows the user to lock the present light intensity level as a protected preset light intensity level to which the dimmer should set the lighting load 116 when turned on by actuation of actuator 16. After a protected preset is assigned by a user, the protected preset feature is considered enabled. The user can also disable (or unlock) the protected preset. When the dimmer is turned on via actuator 16 while protected preset is disabled, the dimmer will set the lighting load 116 to the intensity level at which the dimmer was set when the lighting load was last turned off. Accordingly, when the lighting load 116 is turned off via actuator 16, the light intensity level at which the lighting load was set is stored in memory. When the lighting load 116 is turned on via actuator 16, the microcontroller reads from memory the value of the last light intensity level, and causes the lighting load to be set to that level. When the dimmer is turned on via actuator 16 while protected preset is enabled, the dimmer will set the lighting load 116 to the protected preset intensity level. When the lighting load 116 is turned off via actuator 16, the light intensity level at which the lighting load was set is not stored in memory. When the lighting load 116 is turned on, the microcontroller reads the protected preset intensity level value from memory and causes the lighting load to be set to the protected preset level. To enable the protected preset feature by locking the present light intensity level as the protected preset intensity level, a user may follow the following procedure. First, actuator 14 may be used to set the lighting load to a desired intensity level. With the lighting load 116 at the desired intensity level, the user may then “quad tap” actuator 16, i.e., tap actuator 16 four times in rapid succession (e.g., less than ½ sec between taps). The LED corresponding to the level at which the lighting load 116 was initially set will then blink twice, and the microprocessor will cause the selected light intensity level to be stored in memory as the protected preset intensity level. Note that the quad tap is actually a “save” operation. That is, the dimmer enables the user to save in memory a value associated with a current light intensity level as a protected preset value. Thereafter, whenever the lights are turned on, the dimmer will cause the lighting load 116 to go to the stored preset intensity level. Protected preset maybe deactivated by another quad tap. It has been found that, in such a dimmer, protected preset may be accidentally implemented. That is, a user may quad tap actuator 16 and activate or deactivate protected preset inadvertently. Also, the quad tap enables the user to set only one parameter associated with only one feature the dimmer provides. It would be desirable, therefore, if apparatus and methods were available that enabled a user of such a wallbox dimmer to program one or more features of the dimmer using only the limited user interface such a dimmer provides. SUMMARY OF THE INVENTION The invention provides a programmable lighting control device that controls a light intensity level of at least one lamp. The lighting control device may include a user-actuatable intensity selector, a user-actuatable control switch, a user-actuatable air gap controller, and a microcontroller operatively coupled to the intensity selector, the control switch, and the air gap controller. In a normal operational mode, the intensity selector enables a user to select a desired intensity level between a minimum intensity level and a maximum intensity level, the control switch enables the user to turn the lamp on and off, and the air gap controller enables the user to disrupt power to the lighting control device. The device may also include an intensity level indicator in the form of a plurality of light sources, such as LEDs. In normal operational mode, the LED associated with the current light intensity level may be lit. According to the invention, the microcontroller may be adapted to enter a programming mode after determining that the air gap has been opened, that the control switch has been actuated while the air gap is open, that the air gap has been closed while the control switch is actuated, and that the control switch has remained actuated for at least a prescribed period of time after the air gap was closed. Upon entering the programming mode, the dimmer presents a first, or “main,” menu from which the user may select one or more features to program. In the main menu, each of one or more of the LEDs is associated with a respective programmable feature. The microcontroller may cause the LED associated with a default feature to begin to blink at a first, relatively slow rate. While in the main menu, the user may actuate the raise/lower switches to scroll through the list of programmable features. The user may actuate the toggle actuator to select the currently highlighted feature. Depending on the feature selected, the microcontroller may provide either a parameter selection menu or a value selection menu that is associated with the selected feature. In the parameter selection menu, each of one or more LEDs may be associated with a respective parameter that defines the selected feature. Using the raise/lower actuator, the user may scroll through the parameter selection menu and select a highlighted parameter by actuating the control switch actuator. In the value selection menu, each of one or more LEDs may be associated with a respective prescribed value that may be selected for a parameter that defines the selected feature, which parameter may have been selected via a parameter selection menu. Using the raise/lower actuator, the user may scroll through the value selection menu and select a value for the selected parameter. The selected value is stored in memory. The user may exit programming mode and return the dimmer to normal operating mode in a number of ways. For example, the user could do nothing (i.e., not actuate any switch) for a prescribed timeout period. Alternatively, the user could cycle the air gap to exit programming mode, or press and hold the toggle button for a prescribed period of time (e.g., four seconds). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a typical dimmer circuit. FIGS. 2A and 2B depict an example wall control that may be programmable in accordance with the invention. FIG. 3 is a simplified block diagram of example circuitry for a lighting control device according to the invention. FIGS. 4A-C provide a flowchart of a method according to the invention for programming a wallbox dimmer. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS FIG. 3 is a simplified block diagram of example circuitry for a lighting control device 150 according to the invention. The circuitry schematically illustrated in FIG. 3 as W and REM, or any portion thereof, may be contained in a standard back box, such as back box 20. A lighting load 116, which may include one or more lamps, may be connected between the hot and neutral terminals of a standard power source 148 (of 120 V, 60 Hz AC power, for example). Lighting load 116 may include one or more incandescent lamps, for example, though it should be understood that the lighting load 116 may include other loads, such as electronic low voltage (ELV) or magnetic low voltage (MLV) loads, for example, in addition to or instead of incandescent lighting. The lighting load 116 may be connected through a controllably conductive device 118. Controllably conductive device 118 has a control, or gate, input 126, which is connected to a gate drive circuit 131. It should be understood that control inputs on the gate input 126 will render the controllably conductive device 118 conductive or non-conductive, which in turn controls the power supplied to the lighting load 116. Drive circuitry 131 provides control inputs to the controllably conductive device 118 in response to command signals from a microcontroller 132. Phase-controlled dimmers are well known and perform dimming functions by selectively connecting the AC power source 148 to the lighting load 116 during each half-cycle of the AC waveform received from the power source. The AC power may be switched using controllably conductive devices such as triacs, anti-parallel SCRs, field effect transistors (FETs), or insulated gate bipolar transistors (IGBTs). The amount of dimming is determined by the ratio of “ON” time to “OFF” time of the controllably conductive device 118. In conventional forward phase-controlled dimming, the controllably conductive device (triac or SCR) is OFF at the beginning of each half-cycle (i.e., at the zero crossing) and turned ON later in the half-cycle. Forward phase-controlled dimming may be desirable where the load is inductive or resistive, which may include, for example, a magnetic lighting transformer. In reverse phase-controlled dimming, the controllably conductive device (FET or IGBT) is switched ON to supply power to the load at or near the zero crossing and is switched OFF later during the half-cycle. Reverse phase-controlled dimming may be desirable where the load is capacitive, which may include, for example, an electronic transformer connected low voltage lamp. For each method of phase-controlled dimming, the ratio of ON time to OFF time is determined based on a user-selected desired intensity level. Microcontroller 132 may be any programmable logic device (PLD), such as a microprocessor or an application specific integrated circuit (ASIC), for example. Microcontroller 132 generates command signals to LEDs 133. Inputs to microcontroller 132 are received from AC line zero-crossing detector 134 and signal detector 135. Power to microcontroller 132 is supplied by power supply 136. A memory 137, such as an EEPROM (Electrically Erasable Programmable Read-Only Memory), for example, may also be provided. Air gap switch 146 is provided and is normally in the closed state. When air gap switch is opened via air gap switch actuator 17, all components of the lighting control device 150 are cut off from the AC power source 148. Zero-crossing detector 134 determines the zero-crossing points of the input 60 Hz AC waveform from the AC power source 148. The zero-crossing information is provided as an input to microcontroller 132. Microcontroller 132 sets up gate control signals to operate controllably conductive device 118 to provide voltage from the AC power source to lighting load 116 at predetermined times relative to the zero-crossing points of the AC waveform. Zero-crossing detector 134 may be a conventional zero-crossing detector and need not be described here in further detail. In addition, the timing of transition firing pulses relative to the zero crossings of the AC waveform is also known, and need not be described further. Signal detector 135 receives as inputs switch closure signals from switches designated T, R, and L. Switch T corresponds to the toggle switch controlled by switch actuator 16, and switches R and L correspond to the raise and lower switches controlled by the upper portion 14a and lower portion 14b, respectively, of intensity selection actuator 14. Closure of switch T will connect the input of signal detector 135 to the Dimmed Hot terminal of the lighting control device 150 when controllably conductive device 118 is non-conducting, and will allow both positive and negative half-cycles of the AC waveform to reach signal detector 135. Closure of switches R and L will also connect the input of signal detector 135 to the Dimmed Hot terminal when the controllably conductive device 118 is non-conducting. However, when switch R is closed, only the positive half-cycles of the AC waveform are passed to signal detector 135 because of series diode 142. Series diode 142 is connected with its anode to switch R and its cathode to signal detector 135, so that only positive polarity signals are passed by diode 142. In similar manner, when switch L is closed, only the negative half-cycles of the AC waveform are passed to signal detector 135 because of series diode 144, which is connected so as to allow only negative polarity signals to pass to signal detector 135. Signal detector 135 detects when the switches are closed, and outputs signals representative of the state of the switches as inputs to microcontroller 132. Microcontroller 132 determines the duration of closure in response to inputs from signal detector 135. Signal detector 135 may be any form of conventional circuit for detecting a switch closure and converting it to a form suitable as an input to a microcontroller 132. Those skilled in the art will understand how to construct signal detector 135 without the need for further explanation herein. In normal operating mode, closure of a raise switch R, such as by a user depressing actuator 14a, initiates a preprogrammed “raise light level” routine in microcontroller 132 and causes microcontroller 132 to decrease the off (i.e., non-conduction) time of controllably conductive device 118 via gate drive circuit 131. Decreasing the off time increases the amount of time controllably conductive device 118 is conductive, which means that a greater proportion of AC voltage from the AC input is transferred to lighting load 116. Thus, the light intensity level of lighting load 116 may be increased. The off time decreases as long as the raise switch R remains closed. After the raise switch R opens, e.g., by the user releasing actuator 14a, the routine in the microcontroller is terminated, and the off time is held constant. In a similar manner, closure of a lower switch L, such as by a user depressing actuator 14b, initiates a preprogrammed “lower light level” routine in microcontroller 132 and causes microcontroller 132 to increase the off time of controllably conductive device 118 via gate drive circuit 131. Increasing the off time decreases the amount of time controllably conductive device 118 is conductive, which means that a lesser proportion of AC voltage from the AC input is transferred to lighting load 116. Thus, the light intensity level of lighting load 116 may be decreased. The off time is increased (without turning off the dimmer) as long as the lower switch L remains closed. After the lower switch L opens, e.g., by the user releasing actuator 14b, the routine in the microcontroller 132 is terminated, and the off time is held constant. The toggle switch T is closed in response to actuation of actuator 16, and will remain closed for as long as actuator 16 is depressed. Signal detector 135 provides a signal to microcontroller 132 indicating that the toggle switch T has been closed. Microcontroller 132 determines the length of time that the toggle switch T has been closed. Microcontroller 132 can discriminate between a closure of the toggle switch T that is of only transitory duration and a closure of the toggle switch T that is of more than a transitory duration. Thus, microcontroller 132 is able to distinguish between a “tap” of the actuator 16 (i.e., a closure of transitory duration) and a “hold” of the actuator 16 (i.e., a closure of more than transitory duration). Microcontroller 132 is also able to determine when the toggle switch T is transitorily closed a plurality of times in succession. That is, microcontroller 132 is able to determine the occurrence of two or more taps in quick succession. In an example embodiment of a wallbox dimmer operating in normal operational mode, different closures of the toggle switch T will result in different effects depending on the state of lighting load 116 when the actuator 16 is actuated. For example, when the lighting load 116 is at an initial, non-zero intensity level, a single tap of actuator 16, i.e., a transitory closure of toggle switch T, may cause the load to fade to off. Two taps in quick succession may initiate a routine in microcontroller 132 that causes the lighting load 116 to fade from the initial intensity level to the full intensity level at a preprogrammed fade rate. A “hold” of the actuator 16, i.e., a closure of toggle switch T for more than a transitory duration, may initiate a routine in microcontroller 132 that gradually fades in a predetermined fade rate sequence over an extended period of time from the initial intensity level to off. When the lighting load 116 is off and microcontroller 132 detects a single tap or a closure of more than transitory duration, a preprogrammed routine is initiated in microcontroller 132 that causes the lighting load 116 to fade from off to a preset desired intensity level at a preprogrammed fade rate. Two taps in quick succession will initiate a routine in microcontroller 132 that causes the light intensity level of the lighting load 116 to fade at a predetermined rate from off to full. The fade rates may be the same, or they may be different. Preferably, all of the previously-described circuitry is contained in a standard, single-gang wallbox, schematically illustrated in FIG. 3 by the dashed outline labeled W. An additional set of switches R′, L′ and T′ may be provided in a remote location in a separate wallbox, schematically illustrated in FIG. 3 by the dashed outline, labeled REM. The action of switches R′, L′ and T′ corresponds to the action of switches R, L and T. A wallbox dimmer such as described above may be preprogrammed to provide certain features, examples of which are described below. The value(s) associated with the feature(s) may be stored in memory 137 in the wallbox dimmer. When the feature is employed during normal operation of the dimmer, the microcontroller 132 may access the memory 137 to retrieve the value(s) and cause the dimmer to perform according to the stored value(s). According to the invention, a user may “program” the dimmer by selecting respective desired values for each of one or more features provided by the dimmer. It will be appreciated from the description below that, in general, the dimmer will perform differently according to different values for the features. Examples of such features include, without limitation, protected preset, high-end trim, low-end trim, adjustable delay, fade time, and load type. Each of these features will now be described, along with typical values that may be set for the features. As described above, “protected preset” is a feature that allows the user to lock the present light intensity level as a protected preset lighting intensity to which the dimmer should set the lighting load 116 turned on by actuation of actuator 16. When the dimmer is turned on via actuator 16 while protected preset is disabled, the dimmer will set the lighting load 116 to the intensity level at which the dimmer was set when the lighting load was last turned off. When the dimmer is turned on via actuator 16 while protected preset is enabled, the dimmer will set the lighting load 116 to the protected preset intensity level. According to an aspect of the invention, the protected preset value may be user-programmed. That is, the user may select a value from among a plurality of allowable values for the protected preset light intensity level. When the lighting load 116 is turned on with protected preset enabled, the microcontroller 132 will access the memory 137 to retrieve the user-selected value, and cause the lighting load 116 to be set to the intensity level represented by that value. “High end trim” is a feature that governs the maximum intensity level to which the lighting load 116 may be set by the dimmer. Typical values for the high end trim range between about 60% and about 100% of full intensity. In an example embodiment, the high end trim may be preprogrammed to about be 90% of full intensity. In a wallbox dimmer according to the invention, high end trim is a feature that may be user-programmed as described below. Similarly, “low end trim” is a feature that governs the minimum intensity level to which the lighting load 116 may be set by the dimmer. Typical values for the low end trim range between about 1% and about 20% of full intensity. In an example embodiment, the low end trim may be preprogrammed to about be 10% of full intensity. In a wallbox dimmer according to the invention, low end trim is a feature that may be user-programmed as described below. “Delay-to-off” is a feature that causes the lighting load 116 to remain at a certain intensity level for a prescribed period of time before fading to off. Such a feature may be desirable in certain situations, such as, for example, when a user wishes to turn out bedroom lights before retiring, but still have sufficient light to make his way safely to bed from the location of the wallbox dimmer before the lights are completely extinguished. Similarly, the night staff of a large building may need to extinguish ambient lights from a location that is some distance away from an exit, and may wish to delay the fade to off for a period of time sufficient for them to walk safely to the exit. Typical delay-to-off times range from about 10 seconds to about 60 seconds. According to an aspect of the invention, the delay-to-off time may be user-programmed. That is, the user may select a value from among a plurality of allowable values for the delay-to-off time. When the lighting load is turned off with the delay-to-off feature enabled, the microcontroller 132 will access the memory 137 to retrieve the user-selected value of delay-to-off feature. The microcontroller 132 will cause the lighting load 116 to remain at the current intensity level for a time represented by the user-selected value of delay-to-off feature. “Fading” is a feature, described generally above, whereby the dimmer causes the lighting load to change from one intensity level to another at a certain rate or plurality of successive rates based on different closures of the toggle switch T and depending on the state of lighting load 116 when the actuator 16 is actuated. U.S. Pat. No. 5,248,919 (“the 919 patent”) discloses a lighting control device that is programmed to cause a lighting load to fade: a) from an off state to a desired intensity level, at a first fade rate, when the input from a user causes a closure of the intensity actuation switch; b) from any intensity level to the maximum intensity level, at a second fade rate, when the input from a user causes two switch closures of transitory duration in rapid succession; c) from the desired intensity level to an off state, at a third fade rate, when the input from a user causes a single switch closure of a transitory duration; and d) from the desired intensity level to an off state, at a fourth fade rate, when the input from a user causes a single switch closure of more than a transitory duration. The lighting control device may cause the load to fade from a first intensity level to a second intensity level at a fifth fade rate when the intensity selection actuator is actuated for a period of more than transitory duration. The 919 patent is incorporated herein by reference. Co-pending U.S. patent application Ser. No. 10/753,035, filed on Jan. 7, 2004, entitled Lighting Control Device Having Improved Long Fade Off (“the 035 application), discloses a lighting control device that is capable of activating a long fade off from any light intensity and is incorporated herein by reference. According to an aspect of the invention, any or all of the features that define the fade features may be user-programmed. When the actuator 16 is actuated, depending on the state of lighting load 116 when the actuator 16 is actuated, and based on the number and type of closures of the toggle switch T, the microcontroller 132 may access the memory 137 to retrieve one or more of the user-selected values. The microcontroller 132 will cause the lighting load 116 to fade according to a fade profile based on the user-selected value of fade feature. Another feature that may be programmed in accordance with the invention is “load type.” As described above, the load type may be inductive, resistive, or capacitive. Forward phase-controlled dimming may be desirable where the load is inductive or resistive; reverse phase-controlled dimming may be desirable where the load is capacitive. Thus, the load type may be defined, at least in part, by a feature having a value associated with either forward phase control or reverse phase control. FIGS. 4A-C provide flowcharts of an example embodiment of a method according to the invention for programming a wallbox dimmer. Such a method may be implemented as a set of computer-executable instructions stored on a computer-readable medium, such as a random-access or read-only memory within the wallbox dimmer. Such computer-executable instructions may be executed by a microcontroller, such as a microprocessor, within the wallbox dimmer. The microcontroller 132 is referred to as “μC” in FIGS. 4A-C. The flow begins assuming the dimmer is operating in its normal operational mode. In normal operational mode, the toggle actuator 16 toggles the lights between on and off. A double tap on the toggle actuator 16 causes the lights to go to 100% intensity. Pressing and holding the toggle actuator 16 causes the lights to fade to off. Actuating the upper portion 14a of actuator 14 raises the intensity level of the lighting load 116. Actuating the lower portion 14b of actuator 14 lowers the intensity level of the lighting load 116. When the lights are on, the LED corresponding to the current intensity level is lit. When the lights are off, the LEDs are dimly lit, with the LED corresponding to the preset level being slightly brighter than the others. In an example embodiment, the dimmer may enter a programming mode in accordance with the following beginning in normal operation at 800. First, at step 802, the user opens the air gap switch 146 by opening the air gap switch actuator 17. At step 804, power is cutoff from the microcontroller 132 because the air gap switch 146 has been opened. At step 806, with the air gap switch 146 open, the user presses and begins to hold the toggle actuator 16. At step 808, while holding the toggle actuator 16, the user closes the air gap actuator 17. At step 810, the microcontroller 132 detects a power-up condition, i.e., that power has been restored through the air gap switch 146. At step 812, the microcontroller 132 detects that the toggle actuator 16 is being held closed. At step 814, the user continues to press and hold the toggle actuator 16 for at least a prescribed period of time (e.g., four seconds) after the air gap switch 146 is closed. If, at step 816, the microcontroller 132 determines that the toggle actuator 16 has been held for at least the prescribed period of time, then, at step 818, the dimmer enters programming mode. Otherwise, at step 819, the dimmer remains in normal operational mode. Upon entering the programming mode, the dimmer enters a feature selection mode in which the user may select one or more features to program. In the feature selection mode, each of one or more of the LEDs is associated with a respective programmable feature. The microcontroller 132 may cause the LED associated with a default feature to begin to blink at a relatively slow first blink rate. Preferably, the default feature is associated with the lowest LED of light indicators 18. The list of programmable features presented in the feature selection mode may be referred to as the “main menu.” At step 824, the microcontroller 132 causes the LED associated with the default feature to blink at the first blink rate. In an example embodiment, the first blink rate may be 2 Hz, though it should be understood that the first blink rate may be any desired rate. While in the feature selection mode, the user may actuate the raise/lower switches to scroll through the list of programmable features. For example, at step 830, the user may actuate the raise-intensity actuator 14a. At step 832, the microcontroller 132 detects that the raise-intensity switch R has been closed. At step 834, the microcontroller 132 causes the LED associated with the “next” programmable feature to blink at the first blink rate. The decision as to which programmable feature is “next” is purely arbitrary and can be programmed into the microcontroller 132. In an example embodiment, the “next” feature is the feature associated with the LED that is just above the currently blinking LED. The user may continue to scroll through the list of programmable features by continuing to hold down the raise-intensity actuator 14a (or by successively pressing the raise-intensity actuator 14a). If the microcontroller 132 determines that the uppermost LED is currently blinking, then, at step 834, the microcontroller causes the uppermost LED to continue to blink. Similarly, at step 840, the user may actuate the lower-intensity actuator 14b. At step 842, the microcontroller 132 detects that the lower-intensity switch has been closed. At step 846, the microcontroller 132 causes the LED associated with the “next” programmable feature to blink at the first blink rate. Again, the decision as to which programmable feature is “next” is purely arbitrary, and can be programmed into the microcontroller 132. In an example embodiment, the “next” feature is the feature associated with the LED that is just below the currently blinking LED. The user may continue to scroll through the list of programmable features by continuing to hold down the lower-intensity actuator 14b (or by successively pressing the lower-intensity actuator 14b). If the microcontroller 132 determines that the lowermost LED is currently blinking, then, at step 844, the microcontroller causes the lowermost LED to continue to blink. At step 850 the user may actuate the toggle actuator 16 to select the currently presented feature (i.e., the feature associated with the LED that is blinking when the user actuates the toggle actuator 16). At step 852, the microcontroller 132 detects that the toggle switch T has been actuated and, at step 856, the microcontroller enters a value selection mode. In the value selection mode, each of one or more LEDs is associated with a respective prescribed value that may be selected for the selected feature. The user may scroll through the values and select a value for the selected feature. If, at step 900, the microcontroller 132 determines that the selected feature is currently enabled, then, upon entering the value selection mode, at step 902, the LED associated with the current value for the selected feature will begin to blink at a relatively fast, second blink rate (i.e., at a rate that is faster than the first blink rate). In an example embodiment, the second blink rate may be 8 Hz, though it should be understood that the second blink rate may be any desired rate. If, at step 900, the microcontroller 132 determines that the selected feature is not currently enabled (i.e., if the selected feature is disabled), then, at step 903, upon entering the value selection mode, no LED will light or blink. While in the value selection mode, the user may actuate the raise-intensity actuator 14a and the lower-intensity actuator 14b to scroll through the list of available values associated with the selected feature. For example, at step 904, the user may actuate the raise-intensity actuator 14a. At step 906, the microcontroller 132 detects that the raise-intensity switch R has been closed. At step 908, the microcontroller 132 causes the LED associated with the “next” available value to blink at the second blink rate. The decision as to which value is “next” is purely arbitrary, and can be programmed into the microcontroller 132. In an example embodiment, the “next” value is the value associated with the LED that is just above the currently blinking LED. Alternatively, the “next” value could be a value associated with the same LED as the currently blinking LED. For example, this may be the case if the selected feature is the protected preset intensity level, when the value can be any intensity level between 1% and 100% (i.e. each value will not have a unique LED to be associated with). The user may continue to scroll through the list of available values by continuing to hold down the raise-intensity actuator 14a (or by successively pressing the raise-intensity actuator 14a). If the microcontroller 132 determines that the uppermost LED is currently blinking, then, at step 908, the microcontroller causes the uppermost LED to continue to blink. If the microcontroller 132 determines that the feature is disabled and the raise-intensity actuator is pressed, then the microcontroller causes the lowermost LED to blink. Similarly, at step 912, the user may actuate the lower-intensity actuator 14b. At step 914, the microcontroller 132 detects that the lower-intensity switch L has been closed. At step 916, the microcontroller 132 causes the LED associated with the “next” value to blink at the second blink rate. Again, the decision as to which value is “next” is purely arbitrary, and can be programmed into the microcontroller 132. In an example embodiment, the “next” value is the value associated with the LED that is just below the currently blinking LED. Alternatively, the “next” value could be the value associated with the same LED as the currently blinking LED. The user may continue to scroll through the list of available values by continuing to hold down the lower-intensity actuator 14b (or by successively pressing the lower-intensity actuator 14b). If the microcontroller 132 determines that the lowermost LED is currently blinking, then, at step 916, the microcontroller causes no LEDs to blink and disables the current feature. If the microcontroller 132 determines that the feature is disabled and the lower-intensity actuator is pressed, then the microcontroller keeps the feature disabled with no LEDs blinking. At step 922, the user selects a value for the selected feature, and, at step 924, the microcontroller 132 stores the value in memory 137. The user may select the value at step 922 in any of a number of ways. In a first embodiment of the invention, the feature value may be set (i.e., stored in memory 137) as the user cycles through the prescribed values. Thus, the user may select a value for the feature by merely scrolling through the list of prescribed values until the desired value is highlighted (e.g., the LED associated with the desired value is blinking). Also, for certain features, e.g., protected preset, the dimmer may also be programmed to control the intensity of the lighting load 116 as the user cycles through the prescribed values. Thus, the user may see the effect the currently presented value will have on dimmer performance. In an alternate embodiment, the microcontroller 132 stores the currently presented value (i.e., the value that is associated with the LED that is blinking when the rocker is released) after the user releases the raise-intensity actuator 14a or the lower-intensity actuator 14b for a period of time. Thus, the user can scroll through the values without changing the value in memory 137 until the actuator 14 is released for the prescribed period of time. In a third embodiment, the value of the feature does not change in memory 137 unless the toggle actuator 16 is selected within a prescribed period of time from the time at which the raise-intensity actuator 14a or the lower-intensity actuator 14b is released. If a feature is defined by more than one variable parameter, it might be desirable to provide another mode presenting a list of user-programmable parameters similar to the feature selection mode. According to an aspect of the invention, any or all of these variable parameters may be programmed. That is, if the user selects a feature in the feature selection mode that is defined by more than one parameter, then a parameter selection mode (rather than the value selection mode) may be entered wherein each of one or more LEDs is associated with a respective variable parameter that defines the selected feature. The user may scroll through the parameters of the parameter selection mode and select a parameter to program. For example, fading is a feature that may be defined by a number of parameters, such as, fade off rate, fade off time, long fade time, button hold time, etc. Fading may be presented as an option in the feature selection mode by association with one the LEDs. If the user selects fading in the feature selection mode, then a parameter selection mode may be entered wherein each of one or more LEDs is associated with a respective variable parameter that defines the fading feature. It should be understood that, even where the selected feature has only one programmable variable parameter associated with it, a parameter selection mode could be provided (though such a mode would, by definition, offer only one variable parameter from which to choose). It should also be understood that a parameter selection mode need not be provided, even where a programmable feature has more than one variable parameter. For example, the feature selection mode may present not just the feature (e.g., fading), but rather, the programmable parameters that define the feature (e.g., fade off rate, fade off time, long fade time, button hold time, etc). To go back to a previous mode (e.g., to go from the value selection mode to the feature selection mode if there is no parameter selection mode associated with the selected feature, or, if there is a parameter selection mode, to go from the value selection mode to the parameter selection mode or from the parameter selection mode to the feature selection mode), the user may press the toggle actuator 16. In an example embodiment, the user may exit programming mode and return the dimmer to normal operating mode in any of three ways. First, the user could do nothing (i.e., not actuate any switch) for a prescribed timeout period. Alternatively, the user could cycle the air gap switch actuator 17. A third way to exit programming mode is to press and hold the toggle actuator 16 for a prescribed period of time (e.g., four seconds). Preferably, programming mode may be exited from the feature selection mode, any parameter selection mode, or any value selection mode. The following table provides examples of programmable features that may be provided by a wallbox dimmer according to the invention. For each feature, example values that define the feature are provided. Programmable Feature Prescribed Value High End Trim (%) 100, 95, 90, 85, 80, 75, 70 Low End Trim (%) 0, 5, 10, 15, 20, 25, 30 Load Type Reverse Phase Controlled, Forward Phase Controlled Delay-To-Off (sec) 0, 10, 20, 30, 40, 50, 60 Protected Preset Any level between high-end and low-end Fade Off Rate (sec) 0.5, 1, 2, 3, 4 Fade Off Time (sec) 1, 3, 5, 10, 15 It should be understood that the foregoing examples are provided for illustrative purposes only, and that other features may be programmed in accordance with the principles of the invention. Other possible features that may be programmed include, without limitation, zone exclusion, disabling of certain remote commands, and addressing of remote dimmers in a dimming system wherein a number of remote dimmers are controlled by a master control. Thus there have been described apparatus and methods for programming certain features provided by a wallbox dimmer. Other modifications of these apparatus and methods and of their application to the design of electronic dimmers will be readily apparent to one of ordinary skill in the art, but are included within the invention, which is limited only by the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>FIG. 1 depicts a typical dimmer circuit 100 comprising a source of electrical energy or power supply 112 , a dimmer 114 , and a lighting load 116 . The lighting load 116 may be a lamp set comprising one or more lamps adapted to be connected between the hot and neutral terminals of a standard source of electrical energy. The lamp set may include one or more incandescent lamps and/or other lighting loads such as electronic low voltage (ELV) or magnetic low voltage (MLV) loads, for example. The power supply 112 supplies an electrical waveform to the dimmer 114 . The dimmer regulates the delivery of electrical energy from the power supply 112 to the lighting load 116 . The dimmer 114 may include a controllably conductive device 118 and a control circuit 120 . The controllably conductive device 118 may include an input 122 adapted to be coupled to the power supply 112 , an output 124 adapted to be coupled to the lighting load 116 , and a control input 126 . The control circuit 120 may have an input 128 coupled to the input 122 of the controllably conductive device 118 and an output 130 coupled to the control input 126 of the controllably conductive device 118 . A typical, AC, phase-control dimmer regulates the amount of energy supplied to the lighting load 116 by conducting for some portion of each half-cycle of the AC waveform, and not conducting for the remainder of the half-cycle. Because the dimmer 114 is in series with the lighting load 116 , the longer the dimmer 114 conducts, the more energy will be delivered to the lighting load 116 . Where the lighting load 116 is a lamp set, the more energy delivered to the lighting load 116 , the greater the light intensity level of the lamp set. In a typical dimming scenario, a user may adjust a control to set the light intensity level of the lamp set to a desired light intensity level. The portion of each half-cycle for which the dimmer conducts is based on the selected light intensity level. The controllably conductive device 118 may include a solid state switching device, which may include one or more triacs, which may be thyristors or similar control devices. Conventional light dimming circuits typically use triacs to control the conduction of line current through a load, allowing a predetermined conduction time, and control the average electrical power to the light. One technique for controlling the average electrical power is forward phase control. In forward phase control, a switching device, which may include a triac, for example, is turned on at some point within each AC line voltage half cycle and remains on until the next current zero crossing. Forward phase control is often used to control energy to a resistive or inductive load, which may include, for example, a magnetic lighting transformer. Because a triac device can only be selectively turned on, a power-switching device, such as a field effect transistor (FET), a MOSFET (metal oxide semiconductor FET), or an insulated gate bipolar transistor (IGBT), for example, may be used for each half cycle of AC line input when turn-off phase is to be selectable. In reverse phase control, the switch is turned on at a voltage zero-crossing of the AC line voltage and turned off at some point within each half cycle of the AC line current. A zero-crossing is defined as the time at which the voltage equals zero at the beginning of each half-cycle. Reverse phase control is often used to control energy to a capacitive load, which may include for example, an electronic transformer connected low voltage lamp. The switching device may have a control or “gate” input 126 that is connected to a gate drive circuit, such as an FET drive circuit, for example. Control inputs on the gate input render the switching device conductive or non-conductive, which in turn controls the energy supplied to the load. FET drive circuitry typically provides control inputs to the switching device in response to command signals from a microcontroller. FET protection circuitry may also be provided. Such circuitry is well known and need not be described herein. The microcontroller may be any processing device such as a programmable logic device (PLD), a microprocessor, or an application specific integrated circuit (ASIC), for example. Power to the microcontroller may be supplied by a power supply. A memory, such as an EEPROM, for example, may also be provided. Inputs to the microcontroller may be received from a zero-crossing detector. The zero-crossing detector determines the zero-crossing points of the input waveform from the power supply 112 . The microcontroller sets up gate control signals to operate the switching device to provide voltage from the power supply 112 to the load 116 at predetermined times relative to the zero-crossing points of the waveform. The zero-crossing detector may be a conventional zero-crossing detector, and need not be described here in further detail. In addition, the timing of transition firing pulses relative to the zero crossings of the waveform is also known, and need not be described further. FIGS. 2A and 2B depict an example lighting control device 114 that may be programmable in accordance with the invention. As shown, the lighting control device 114 may include a faceplate 12 , a bezel 13 , an intensity selection actuator 14 for selecting a desired level of light intensity of a lighting load 16 controlled by the lighting control device, a control switch actuator 16 , and an air gap actuator 17 . Faceplate 12 need not be limited to any specific form, and is preferably of a type adapted to be mounted to a conventional wall box commonly used in the installation of lighting control devices. Likewise, bezel 13 and actuators 14 , 16 , and 17 are not limited to any specific form, and may be of any suitable design that permits manual actuation by a user. Actuation of the upper portion 14 a of actuator 14 increases or raises the light intensity of lighting load 116 , while actuation of lower portion 14 b of actuator 14 decreases or lowers the light intensity. Actuator 14 may control a rocker switch, two separate push switches, or the like. Actuator 16 may control a push switch, though actuator 16 may be a touch-sensitive membrane or any other suitable type of actuator. Actuators 14 and 16 may be linked to the corresponding switches in any convenient manner. The switches controlled by actuators 14 and 16 may be directly wired into the control circuitry to be described below, or may be linked by an extended wired link, infrared link, radio frequency link, power line carrier link, or otherwise to the control circuitry. Air gap actuator 17 is provided in order to open an air gap switch in the lighting control device 114 . The air gap switch disconnects the power supply 112 from the controllably conductive device 118 , the control circuit 130 , and the lighting load 116 . The air gap switch is opened by pulling the air gap actuator 17 away from the faceplate 12 of the lighting control device 114 . Lighting control device 114 may also include an intensity level indicator in the form of a plurality of light sources 18 . Light sources 18 may be light-emitting diodes (LEDs), for example, or the like. Light sources 18 may occasionally be referred to herein as LEDs, but it should be understood that such a reference is for ease of describing the invention and in not intended to limit the invention to any particular type of light source. Light sources 18 may be arranged in an array (such as a linear array as shown) representative of a range of light intensity levels of the lighting load being controlled. The intensity levels of the lighting load may range from a minimum intensity level, which is preferably the lowest visible intensity, but which may be zero, or “full off,” to a maximum intensity level, which is typically “full on.” Light intensity level is typically expressed as a percent of full intensity. Thus, when the lighting load is on, light intensity level may range from 1% to 100%. By illuminating a selected one of light sources 18 depending upon light intensity level, the position of the illuminated light source within the array may provide a visual indication of the light intensity relative to the range when the lighting load being controlled is on. For example, seven LEDs are illustrated in FIGS. 2A and 2B . Illuminating the uppermost LED in the array may indicate that the light intensity level is at or near maximum. Illuminating the center LED may indicate that the light intensity level is at about the midpoint of the range. Any convenient number of light sources 18 may be used, and it should be understood that a larger number of light sources in the array will yield a commensurately finer gradation between intensity levels within the range. When the lighting load 116 being controlled is off, the LED representative of the intensity level at which the lighting load will turn on to may be illuminated at a relatively high illumination level, while the remaining light sources may be illuminated at a relatively low level of illumination. This enables the light source array to be more readily perceived by the eye in a darkened environment, which assists a user in locating the lighting control device 114 in a dark room, for example, in order to actuate the lighting control device 114 to control the lights in the room. Still, sufficient contrast may be provided between the level-indicating LED and the remaining LEDs to enable a user to perceive the relative intensity level at a glance. Lighting control device 114 may include a standard back box 20 having a plurality of high voltage screw terminal connections 22 H, 22 N, 22 D that may be connections for hot, neutral, and dimmed hot, respectively. Such lighting control devices typically provide certain features such as, for example, protected preset, fading, and the like. Some such lighting control devices may enable a user to set a value associated with a feature the lighting control device provides. For example, lighting control devices are known that enable a user to set a light intensity value associated with the “protected preset” feature (see, for example, U.S. Pat. No. 6,169,377, which describes a lighting control unit having the protected or “locked” preset feature). Protected preset is a feature that allows the user to lock the present light intensity level as a protected preset light intensity level to which the dimmer should set the lighting load 116 when turned on by actuation of actuator 16 . After a protected preset is assigned by a user, the protected preset feature is considered enabled. The user can also disable (or unlock) the protected preset. When the dimmer is turned on via actuator 16 while protected preset is disabled, the dimmer will set the lighting load 116 to the intensity level at which the dimmer was set when the lighting load was last turned off. Accordingly, when the lighting load 116 is turned off via actuator 16 , the light intensity level at which the lighting load was set is stored in memory. When the lighting load 116 is turned on via actuator 16 , the microcontroller reads from memory the value of the last light intensity level, and causes the lighting load to be set to that level. When the dimmer is turned on via actuator 16 while protected preset is enabled, the dimmer will set the lighting load 116 to the protected preset intensity level. When the lighting load 116 is turned off via actuator 16 , the light intensity level at which the lighting load was set is not stored in memory. When the lighting load 116 is turned on, the microcontroller reads the protected preset intensity level value from memory and causes the lighting load to be set to the protected preset level. To enable the protected preset feature by locking the present light intensity level as the protected preset intensity level, a user may follow the following procedure. First, actuator 14 may be used to set the lighting load to a desired intensity level. With the lighting load 116 at the desired intensity level, the user may then “quad tap” actuator 16 , i.e., tap actuator 16 four times in rapid succession (e.g., less than ½ sec between taps). The LED corresponding to the level at which the lighting load 116 was initially set will then blink twice, and the microprocessor will cause the selected light intensity level to be stored in memory as the protected preset intensity level. Note that the quad tap is actually a “save” operation. That is, the dimmer enables the user to save in memory a value associated with a current light intensity level as a protected preset value. Thereafter, whenever the lights are turned on, the dimmer will cause the lighting load 116 to go to the stored preset intensity level. Protected preset maybe deactivated by another quad tap. It has been found that, in such a dimmer, protected preset may be accidentally implemented. That is, a user may quad tap actuator 16 and activate or deactivate protected preset inadvertently. Also, the quad tap enables the user to set only one parameter associated with only one feature the dimmer provides. It would be desirable, therefore, if apparatus and methods were available that enabled a user of such a wallbox dimmer to program one or more features of the dimmer using only the limited user interface such a dimmer provides. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention provides a programmable lighting control device that controls a light intensity level of at least one lamp. The lighting control device may include a user-actuatable intensity selector, a user-actuatable control switch, a user-actuatable air gap controller, and a microcontroller operatively coupled to the intensity selector, the control switch, and the air gap controller. In a normal operational mode, the intensity selector enables a user to select a desired intensity level between a minimum intensity level and a maximum intensity level, the control switch enables the user to turn the lamp on and off, and the air gap controller enables the user to disrupt power to the lighting control device. The device may also include an intensity level indicator in the form of a plurality of light sources, such as LEDs. In normal operational mode, the LED associated with the current light intensity level may be lit. According to the invention, the microcontroller may be adapted to enter a programming mode after determining that the air gap has been opened, that the control switch has been actuated while the air gap is open, that the air gap has been closed while the control switch is actuated, and that the control switch has remained actuated for at least a prescribed period of time after the air gap was closed. Upon entering the programming mode, the dimmer presents a first, or “main,” menu from which the user may select one or more features to program. In the main menu, each of one or more of the LEDs is associated with a respective programmable feature. The microcontroller may cause the LED associated with a default feature to begin to blink at a first, relatively slow rate. While in the main menu, the user may actuate the raise/lower switches to scroll through the list of programmable features. The user may actuate the toggle actuator to select the currently highlighted feature. Depending on the feature selected, the microcontroller may provide either a parameter selection menu or a value selection menu that is associated with the selected feature. In the parameter selection menu, each of one or more LEDs may be associated with a respective parameter that defines the selected feature. Using the raise/lower actuator, the user may scroll through the parameter selection menu and select a highlighted parameter by actuating the control switch actuator. In the value selection menu, each of one or more LEDs may be associated with a respective prescribed value that may be selected for a parameter that defines the selected feature, which parameter may have been selected via a parameter selection menu. Using the raise/lower actuator, the user may scroll through the value selection menu and select a value for the selected parameter. The selected value is stored in memory. The user may exit programming mode and return the dimmer to normal operating mode in a number of ways. For example, the user could do nothing (i.e., not actuate any switch) for a prescribed timeout period. Alternatively, the user could cycle the air gap to exit programming mode, or press and hold the toggle button for a prescribed period of time (e.g., four seconds). | 20040715 | 20070313 | 20060119 | 64436.0 | H05B3702 | 2 | VU, JIMMY T | PROGRAMMABLE WALLBOX DIMMER | UNDISCOUNTED | 0 | ACCEPTED | H05B | 2,004 |
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10,892,588 | ACCEPTED | Semiconductor device having sufficient process margin and method of forming same | According to some embodiments of the invention, a substrate doped with a P type impurity is provided. An N type impurity is doped into the substrate to divide the substrate into a P type impurity region and an N type impurity region. Active patterns having a first pitch are formed in the P type and N type impurity regions. Gate patterns having a second pitch are formed on the active patterns in a direction substantially perpendicular to the active patterns. Other embodiments are described and claimed. | 1. A semiconductor device comprising: P type and n type impurity regions provided to a unit cell region of a substrate; active patterns disposed in the p type and n type impurity regions, the active patterns having a first pitch; and gate patterns disposed on the active patterns in a direction substantially perpendicular to the active patterns, the gate patterns having a second pitch: 2. The semiconductor device of claim 1, wherein the first pitch is substantially identical to the second pitch. 3. The semiconductor device of claim 1, wherein the unit cell region comprises a first side and a second side substantially perpendicular to the first side, and wherein the first side has a length substantially equal to an integral multiple of the first pitch. 4. The semiconductor device of claim 3, wherein the second side has a length substantially equal to an integral multiple of the second pitch. 5. A method of manufacturing a semiconductor device comprising: providing a substrate doped with a P type impurity; doping an N type impurity into the substrate to divide the substrate into a P type impurity region and an N type impurity region; forming active patterns having a first pitch in the P type and N type impurity regions; and forming gate patterns having a second pitch on the active patterns in a direction substantially perpendicular to the active patterns. 6. The method of claim 5, wherein the first pitch is substantially the same as the second pitch. 7. The method of claim 5, wherein the unit cell region comprises a first side and a second side substantially perpendicular to the first side, and wherein the first side has a length substantially equal to an integral multiple of the first pitch. 8. The method of claim 7, wherein the second side has a length substantially equal to an integral multiple of the second pitch. 9. An SRAM device comprising: P type and N type wells provided in a unit cell region of a substrate; active patterns disposed in the P type and N type wells, the active patterns having a first pitch; and gate patterns disposed on the active patterns in a direction substantially perpendicular to the active patterns, the gate patterns having a second pitch. 10. The SRAM device of claim 9, wherein the first pitch is substantially the same as the second pitch. 11. The SRAM device of claim 9, wherein the unit cell region comprises a first side and a second side substantially perpendicular to the first side, and wherein the first side has a length substantially equal to an integral multiple of the first pitch. 12. The SRAM device of claim 11, wherein the first side of the cell region has a length substantially equal to an integral multiple of the first pitch. 13. The SRAM device of claim 11, wherein the second side of the cell region has a length substantially equal to an integral multiple of the second pitch. 14. The SRAM device of claim 9, further comprising: an insulating interlayer formed on the active patterns and the gate patterns; and contacts disposed on the insulating interlayer for being electrically contacted with the active and gate patterns, wherein the contacts are disposed to have third pitches in an X direction and fourth pitches in a Y direction substantially perpendicular to the X direction, wherein the third pitches are substantially equal to an integral multiple of a minimum pitch among the third pitches, and wherein the fourth pitches are substantially equal to an integral multiple of a minimum pitch among the fourth pitches. 15. The method of claim 9, wherein a long side of the unit cell region is substantially an integral multiple of a short side of the unit cell region. 16. The SRAM device of claim 9, wherein the active patterns are disposed substantially in parallel. 17. A method of manufacturing an SRAM device comprising: doping a substrate with a P type impurity; doping an N type impurity into the substrate to divide the substrate into a P type well and an N type well; forming active patterns having a first pitch in the P type and N type wells; and forming gate patterns having a second pitch on the active patterns in a direction substantially perpendicular to the active patterns. 18. The method of claim 17, wherein the first pitch is substantially identical to the second pitch. 19. The method of claim 17, wherein the unit cell region comprises a first side and a second side substantially perpendicular to the first side, and wherein the first side of the unit cell region has a length substantially equal to an integral multiple of the first pitch. 20. The method of claim 19, wherein the second side of the unit cell region has a length substantially equal to an integral multiple of the second pitch. 21. The method of claim 17, further comprising: forming an insulating interlayer on the active and gate patterns; etching the insulating interlayer to form contact holes partially exposing surfaces of the active and gate patterns, the contact holes being disposed to have third pitches in an X direction and fourth pitches in a Y direction substantially perpendicular to the X direction, the third pitches substantially equal to an integral multiple of a minimum pitch among the third pitches, and the fourth pitches substantially equal to an integral multiple of a minimum pitch among the fourth pitches; and filling the contact holes with a conductive layer to form contacts. 22. The method of claim 21, wherein forming the contact holes comprises: forming a photoresist layer on the insulating interlayer; exposing the photoresist layer using an exposure mask to form a photoresist pattern; and etching the insulating interlayer using the photoresist pattern as an etching mask. 23. The method of claim 22, wherein the exposure mask comprises contact patterns for forming the contacts and dummy contact patterns disposed between the contact patterns. 24. The method of claim 23, wherein the contact patterns and the dummy contact patterns are uniformly spaced apart from each other. | CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 USC § 119 to Korean Patent Application No. 2003-48223, filed on Jul. 15, 2003, the contents of which are herein incorporated by reference in their entirety for all purposes. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, a method of manufacturing a semiconductor device, an SRAM device and a method of manufacturing an SRAM device. More particularly, the present invention relates to a semiconductor device, a method of manufacturing a semiconductor device, an SRAM device and a method of manufacturing an SRAM device having a sufficient process margin. 2. Description of the Related Art Generally, semiconductor memory devices may be categorized as either a dynamic random access memory (DRAM) device or a static random access memory (SRAM) device in accordance with memory type. The SRAM device has a rapid speed, low power consumption, and a simply operated structure. Accordingly, the SRAM device is currently noticed in a semiconductor memory field. Information stored in the DRAM device is periodically refreshed. A periodical refresh of information stored in the SRAM device is, however, not necessary. A typical SRAM device includes two pull-down elements, two pass elements, and two pull-up elements. The SRAM device may be classified as either a full CMOS type, a high load resistor (HLR) type, or a thin film transistor (TFT) type in accordance with the configuration of the pull-up element. A p-channel bulk MOSFET is used as the pull-up element in the full CMOS type. A polysilicon layer having a high resistance value is used as the pull-up element in the HLR type. A p-channel polysilicon TFT is used as the pull-up element in the TFT type. The SRAM device having the full CMOS type of a cell has a low standby current, and also stably operates compared to the SRAM having other types of cells. FIG. 1 is a circuit illustrating a conventional full CMOS type SRAM cell. Referring to FIG. 1, a conventional SRAM cell includes first and second pass transistors Q1 and Q2 for electrically connecting first and second bit lines BL1 and BL2 to first and second memory cell nodes Nd1 and Nd2, respectively, a PMOS type pull-up transistor Q5 electrically connected between the first memory cell node Nd1 and a positive supply voltage Vdd, and an NMOS type pull-down transistor Q3 electrically connected between the first memory cell node Nd1 and a negative supply voltage Vss. The PMOS type pull-up transistor Q5 and the NMOS type pull-down transistor Q3 are controlled by a signal outputted from the second memory cell node Nd2 to thereby provide the positive supply voltage Vdd or the negative supply voltage Vss to the first memory cell node Nd1. The conventional SRAM cell further includes a PMOS type pull-up transistor Q6 electrically connected between the positive supply voltage Vdd and the second memory cell node Nd2, and an NMOS type pull-down transistor Q4 electrically connected between the second memory node Nd2 and the negative supply voltage Vss. The PMOS type pull-up transistor Q6 and the NMOS type pull-down transistor Q4 are controlled by a signal outputted from the first memory cell node Nd1 to thereby provide the positive supply voltage Vdd or the negative supply voltage Vss to the second memory cell node Nd2. The first pass transistor Q1, the NMOS type pull-down transistor Q3 and the PMOS pull-up transistor Q5 are interconnected at the first memory cell node Nd1. The second pass transistor Q2, the NMOS type pull-down transistor Q4 and the PMOS pull-up transistor Q6 are interconnected at the second memory cell node Nd2. The full CMOS type SRAM cell includes the NMOS type transistors Q1, Q2, Q3 and Q4, and the PMOS type transistors Q5 and Q6. When the NMOS and PMOS type transistors are disposed adjacently to each other in one cell, a latch-up and the like may occur, which causes an excessive current to flow between a positive supply voltage line and a negative supply voltage line. To prevent the occurrence of the latch-up, active patterns are disposed so that pitches between the active patterns can have more than two sizes. Namely, in such arrangement of the active patterns, a pitch between an active pattern in which the PMOS type transistor is formed and an active pattern in which the NMOS type transistor is formed is relatively [more] lengthened to perform an entirely elemental isolation between the PMOS and NMOS transistors. On the contrary, a pitch between active patterns in which identical MOS type transistors are disposed is relatively shortened. Thus, in the conventional full CMOS type SRAM cell, since the pitches between the active patterns have more than two sizes that are different from each other, pitches between patterns and pitches between contacts formed on the active pattern, respectively, are also more than two sizes. When the pitches between the patterns formed by the same process are varied as described above, a margin of a photolithography process for forming the patterns is determined based on the minimal one of the pitches between the patterns. Accordingly, the process margin is greatly decreased so that a probability of failures in forming the patterns may be high. Furthermore, it may be difficult to manufacture a highly-integrated semiconductor device by shrinking a cell size of the semiconductor device. Embodiments of the invention address these and other disadvantages of the conventional art. SUMMARY OF THE INVENTION The present invention provides a semiconductor device having an increased margin of a photolithography process. The present invention also provides a method of manufacturing a semiconductor device having an increased margin of a photolithography process. The present invention still also provides an SRAM device having an increased margin of a photolithography process. The present invention still also provides a method of manufacturing an SRAM device having an increased margin of a photolithography process. BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the invention will become readily apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings. FIG. 1 is a circuit diagram illustrating a conventional full CMOS type SRAM cell. FIG. 2 is a layout diagram illustrating active patterns and gate patterns of a full CMOS type SRAM cell in accordance with some embodiments of the invention. FIGS. 3A to 3D are layout diagrams illustrating a method of manufacturing a full CMOS type SRAM cell in accordance with the embodiments illustrated in FIG. 2. FIG. 4 is a plan view diagram illustrating a first exposure mask in accordance with the embodiments illustrated in FIG. 2. FIG. 5 is a plan view diagram illustrating a second exposure mask in accordance with the embodiments illustrated in FIG. 2. FIG. 6 is a plan view diagram illustrating a third exposure mask in accordance with the embodiments illustrated in FIG. 2. FIGS. 7A to 7C, 8A to 8C, and 9 are plan views illustrating photoresist patterns manufactured in accordance with conventional processes and having non-uniform pitches. FIGS. 10A to 10C, 11A to 11C, and 12A to 12C are plan views illustrating photoresist patterns having uniform pitches and manufactured in accordance with embodiments of the invention. FIGS. 13A and 13B are plan views illustrating photoresist patterns for forming contacts, the photoresist patterns formed using a conventional exposure mask having non-uniform pitches. FIGS. 14A to 14C are plan views illustrating photoresist patterns for forming contact holes, the contact holes formed using an exposure mask having uniform pitches in accordance with embodiments of the invention. FIGS. 15A to 15C are plan views illustrating contact holes formed using an exposure mask into which a dummy pattern is inserted in accordance with embodiments of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like numbers refer to similar or identical elements throughout. It will be understood that when an element such as a layer, region or substrate is referred to as being “on” or “onto” another element, it can be directly on the other element or intervening elements may also be present. Hereinafter, a semiconductor device according to several embodiments of the invention will be described and illustrated in detail. A semiconductor device generally includes a data input/output interface, a cell array on which memory cells are disposed, an address recorder, and a controller for controlling writing/reading of a data. A plurality of cells is formed in the cell array to form cell regions. Each unit cell region includes a P type impurity region into which a P type impurity is implanted and an N type impurity region into which an N type impurity is implanted. In the P type and N type impurity regions, active patterns including first and second patterns that have a first pitch are disposed. Here, the first pitch represents a distance between a first side of the first pattern and a first side of the second pattern adjacent to the first pattern. On the active patterns, a number of gate patterns having a second pitch are disposed. The gate patterns are disposed in a direction substantially perpendicular to the active patterns. The first pitch may be substantially identical to the second pitch. A first side of the cell region has a length substantially equal to an integral multiple of the first pitch. A second side of the cell region substantially perpendicular to the first side has a length substantially equal to an integral multiple of the second pitch. Here, the first side is substantially perpendicular to the active patterns. The second side is substantially parallel to the active patterns. Hereinafter, a method of manufacturing a semiconductor device is illustrated in detail. A cell region is disposed in a cell array of a substrate doped with a P type impurity. An N type impurity is implanted selectively into a first region of the cell region to form an N type impurity region. Accordingly, a second region of the cell region except for the first region is a P type impurity region. Active patterns having a first pitch are formed in the N type and P type impurity regions. In particular, a first photoresist pattern having the first pitch is formed on the cell region so that the first photoresist pattern may cover an active region of the cell region. The substrate is etched using the photoresist pattern as an etching mask to form a trench. The trench is filled with a field oxide layer to form the active patterns and field patterns. Gate patterns having a second pitch are formed in a direction perpendicular to and on the active patterns. Particularly, a gate oxide layer is formed on the active patterns of the substrate. A conductive layer is formed on the gate oxide layer. A second photoresist pattern having the second pitch is formed on the conductive layer. The conductive layer and the gate oxide layer are etched using the second photoresist pattern as an etching mask to form the gate patterns having the second pitch. Here, the first pitch may have substantially identical to the second pitch. On the contrary, the first pitch may be different from the second pitch. After the active patterns are formed, the unit cell region of a semiconductor device is determined. A first side of the unit cell region has a length substantially equal to integer times of the first pitch. A second side of the unit cell region substantially perpendicular to the first side has a length substantially equal to integer times of the second pitch. Here, the first side is substantially perpendicular to the active patterns. The second side is substantially parallel to the active patterns. Finally, a semiconductor device is manufactured by performing a doping process for forming source/drain regions, a process for forming an insulating interlayer, and a process for forming a contact, etc. FIG. 2 is a layout diagram illustrating active patterns and gate patterns of a full CMOS type SRAM cell according to some embodiments of the invention. An SRAM cell includes first and second pass transistors for electrically connecting first and second bit lines to first and second memory cell nodes, a PMOS type pull-up transistor electrically connected between the first memory cell node and a positive supply voltage, and an NMOS type pull-down transistor electrically connected between the first memory cell node and a negative supply voltage. The SRAM cell further includes another PMOS type pull-up transistor electrically connected between the positive supply voltage and the second memory cell node, and another NMOS type pull-down transistor electrically connected between the second memory node and the negative supply voltages. That is, the full CMOS type SRAM cell includes both NMOS type transistors and PMOS type transistors. Accordingly, the active patterns are formed to provide the regions in which the PMOS type transistors and the NMOS type transistors are formed in the one SRAM cell. Referring to FIG. 2, a plurality of chips are formed on a substrate. A cell array in which a unit cell is formed is provided in the chips. A region in which the single cell is formed is referred to as a unit cell region C. A P type well corresponding to a well of the NMOS transistor is formed in the unit cell region C. A P type impurity is implanted into the P type well. An N type well corresponding to a well of the PMOS transistor is also formed in the cell region C. An N type impurity is implanted into the N type well. Linear active patterns 102 are disposed at a distance of the same first pitch PI from each other on the N type and P type wells. Here, the first pitch P1 indicates the shortest distance between a first side of a first linear active pattern and a first side of a second linear active pattern adjoining the first linear active pattern. Also, a plurality of gate patterns 104 are formed at a distance of the same second pitch P2 from each other on active patterns 102. The gate patterns 104 are disposed in a direction substantially perpendicular to the active patterns 102. The gate patterns 104 include a gate oxide layer (not shown) and a conductive layer (not shown) formed on the gate oxide layer. The gate patterns 104 are provided to function as gate electrodes of the PMOS and NMOS transistors. Here, the first pitch P1 may have a size substantially identical to the second pitch P2. Alternatively, the first pitch P1 may be different from the second pitch P2. A first side L1 of the cell region C has a length substantially equal to an integral multiple of the first pitch P1. A second side L2 of the cell region C substantially perpendicular to the first side L1 has a length substantially equal to an integral multiple of the second pitch P2. Here, the first side L1 is substantially perpendicular to the active patterns 102. The second side L2 is substantially parallel to the active patterns 102. An insulating interlayer (not shown) is formed on the active patterns 102 and the gate patterns 104. Contacts (not shown) are formed through the insulating interlayer. The contacts include a bit line contact electrically connected to the bit lines, a pass gate contact formed on a surface of the gate patterns 104 of the first and second pass transistors, a positive supply voltage contact, and a negative supply voltage contact. Additionally, although there are not shown in drawings, a word line is connected to the pass gate contact. A positive supply voltage line is connected to the positive supply voltage contact. Also, a negative supply voltage is connected to the negative supply voltage contact. FIGS. 3A to 3D are layout diagrams illustrating a method of manufacturing a full CMOS type SRAM cell in accordance with the embodiments illustrated in FIG. 2. Referring to FIG. 3A, a substrate doped with a P type impurity is provided. An N type impurity is implanted into regions within a cell array region of the substrate to form N type wells 10. The N-type wells 10 are used for forming PMOS transistors. Thus, the substrate is divided into N type wells 10 and P type wells. Referring to FIG. 3B, a pad oxide layer (not shown) is formed on the substrate. A silicon nitride layer (not shown) is formed on the pad oxide layer. A photoresist layer (not shown) is formed on the silicon nitride layer. The photoresist layer is exposed and developed using a first exposure mask, which is illustrated in FIG. 4, to form a first photoresist pattern (not shown) having a first pitch P1. The first photoresist pattern is used for forming active patterns 102. FIG. 4 is a plan view diagram illustrating the first exposure mask according to the embodiments illustrated in FIG. 2. With reference to FIG. 4, the first exposure mask 20 includes a plurality of first shield patterns 22 for blocking light. The first shield patterns 22 correspond to regions for forming an active pattern in the cell array. The pitches between the first shield patterns 22 are substantially identical to the first pitch P1. The first shield patterns 22 are disposed substantially parallel to each other. The silicon nitride layer (not shown) is etched using the first photoresist pattern as an etching mask to form a silicon nitride layer pattern (not shown). The pad oxide layer and the substrate are etched using the silicon nitride layer pattern as a hard mask to form a trench (not shown) defining a field region in the substrate. The trench is filled with a silicon oxide layer (not shown). The silicon oxide layer is polished to expose the pad oxide layer. The silicon nitride layer pattern and the pad oxide layer are removed to form field patterns 100 and active patterns 102. By the above-described process, the active patterns 102 having the first pitch P1 and substantially parallel to each other are formed. The active patterns 102 define a unit cell region C. The cell region C has a first side and a second side substantially perpendicular to the first side. The first side is substantially perpendicular to the first pitch P1. The first side has a length L1 substantially equal to an integral multiple of the first pitch P1. The length L2 of the second side is shorter than the length L1 of the first side. Referring to FIG. 3C, a gate oxide layer (not shown) having a thickness of about 30 Å to about 300 Å is formed on the substrate in which the linear active patterns 102 are formed. Successively, a polysilicon layer (not shown) is formed on the gate oxide layer. A metal silicide layer (not shown) is formed on the polysilicon layer. Further, a photoresist layer (not shown) is formed on the metal silicide layer. The photoresist layer is exposed and developed using a second exposure mask, which is illustrated in FIG. 5, to form a second photoresist pattern (not shown) having a second pitch P2. The second photoresist pattern is used for forming a gate pattern. FIG. 5 is a plan view diagram illustrating the second exposure mask according to the embodiments illustrated in FIG. 2. With reference to FIG. 5, the second exposure mask 30 includes a plurality of second shield patterns 32 for blocking light. The second shield patterns 32 correspond to regions for forming the gate patterns 104. The pitches between second shield patterns 32 are substantially identical to the second pitch P2. The shield patterns 32 are substantially perpendicular to the active patterns 102. Here, the second pitch P2 may be substantially identical to the first pitch P1. Alternatively, the second pitch P2 may be different from the first pitch P1. Returning to FIG. 3C, the metal silicide layer, the polysilicon layer, and the gate oxide layer in turn are subsequently etched using the second photoresist pattern 30 as an etching mask to form the gate patterns 104. The gate patterns 104 having the second pitch P2 are disposed substantially perpendicular to the active patterns 102. The length L2 of the second side is substantially equal to an integral multiple of the second pitch P2. Here, the second side is substantially parallel to the active patterns 102. Referring to FIG. 3D, an insulating interlayer (not shown) is formed on the gate patterns 104. The insulating interlayer may include silicon oxide. A photoresist layer (not shown) is formed on the insulating interlayer. The photoresist layer is exposed and developed using a third exposure mask, which is illustrated in FIG. 6, to form a third photoresist pattern (not shown) used for forming a contact hole. FIG. 6 is a plan view diagram illustrating the third exposure mask 40 according to the embodiments illustrated in FIG. 2. With reference to FIG. 6, the third exposure mask 40 includes contact patterns 42 for exposing regions in which the contact holes are formed, and also includes dummy contact patterns 44 irregularly disposed between the contact patterns 42. Pitches between the contact patterns 42 in an X direction have a length substantially equal to an integral multiple of a minimum pitch between contact patterns 42 in the X direction. Pitches between the contact patterns 42 in a Y direction have a length substantially equal to an integral multiple of a minimum pitch between contact patterns 42 in the Y direction. For example, in FIG. 6, a pitch X1 is substantially identical to a pitch X2. A pitch Y2 is about two times larger than the pitch Y1. Although light is irradiated through the dummy contact patterns 44 onto portions of the photoresist layer, the portions of the photoresist layer are not developed. Thus, the portions of the photoresist layer are not patterned. However, the dummy contact patterns 44 give a proximity effect to the contact patterns 42 adjacent to the dummy contact patterns 44 so that the third photoresist pattern has uniform openings. The dummy contact patterns 44 are disposed in spaces between the contact patterns 42 that have a wide pitch. The pitches between the contact patterns 42 in the X and Y directions have a length substantially equal to an integral multiple of the minimum pitch in the corresponding direction, respectively. Thus, the dummy contact patterns 44 are interpositioned such that a pitch between the dummy contact pattern 44 and the contact pattern 42 is substantially similar to the minimum pitch between the contact patterns 42. Therefore, the entire patterns including the dummy contact patterns 44 and the contact patterns 42 are regularly disposed. As a result, exposure conditions in a space between the contact patterns 42 having a relatively narrow pitch and in a space between the contact patterns 42 having relatively wide pitch are similar so that the third photoresist pattern has the uniform openings. Returning to FIG. 3D, the insulating interlayer is etched using the third photoresist pattern as an etching mask to form contact holes 110 that partially expose surfaces of the gate patterns 104 and the active patterns 102. The contact holes 110 include a bit line contact electrically connected to the bit lines, a pass gate contact formed on a surface of the gate patterns 104 of the first and second pass transistors, a positive supply voltage contact and a negative supply voltage contact. Here, pitches between the contact holes 110 in an X direction have a length substantially equal to an integral multiple of a minimum pitch between the contact holes 110 in the X direction. Pitches between the contact holes 110 in a Y direction have a length substantially equal to an integral multiple of a minimum pitch between contact holes 110 in the Y direction. The contact holes 110 are filled with a conductive layer therein. The conductive layer is planarized to form contacts. The contacts include bit lines, bit line contacts electrically connected to the bit lines, pass gate contacts formed on a surface of the gate patterns 104 of the first and second pass transistors, positive supply voltage contacts, and negative supply voltage contacts. Additionally, a word line is connected to the pass gate contact. A positive supply voltage line is connected to the positive supply voltage contact. A negative supply voltage is connected to the negative supply voltage contact. According to the above described embodiments for forming the SRAM cell, a margin of the processes increases. FIGS. 7A to 7C, 8A to 8C, and 9 show simulation results of forming photoresist patterns for an active region using conventional processes, which results in non-uniform pitches. The exposure equipment used in this simulation had a numerical aperture of about 0.78 and an annular illuminator having a diameter of about 0.72 mm to 0.92 mm. The photoresist pattern in FIG. 7A was formed under conditions where a focus margin was about 0.0 μm. The photoresist pattern in FIG. 7B was formed under conditions where the focus margin was about 0.1 μm. The photoresist pattern in FIG. 7C was formed under conditions where the focus margin was about 0.2 μm. As shown in FIG. 7C, even though the focus margin was about 0.2 μm, the photoresist pattern was not normally formed. FIGS. 8A to 8C show photoresist patterns that were formed using exposure masks whose sizes were shrunk by about 80% from those of the exposure masks that were used for forming the photoresist patterns in FIGS. 7A to 7C. The photoresist pattern in FIG. 8A was formed under conditions where a focus margin was about 0.0 μm. The photoresist pattern in FIG. 8B was formed under conditions where the focus margin was about 0.1 μm. The photoresist pattern in FIG. 8C was formed under conditions where the focus margin was about 0.2 μm. As shown in FIG. 8C, even though the focus margin was about 0.2 μm, the photoresist pattern was not normally formed. FIG. 9 shows an active photoresist pattern that was formed using an exposure mask whose size was shrunk by about 65% from that of the exposure mask that was used for forming the photoresist patterns in FIGS. 7A to 7C. The photoresist pattern in FIG. 9 was formed under conditions where the focus margin was about 0.0 μm. As shown in FIG. 9, even though the focus margin was about 0.0 μm, the photoresist pattern was not normally formed. From the above experimental results, it should be noted that, when the pitches are non-uniform, it is very difficult to normally form the photoresist pattern due to a low focus margin. FIGS. 10A to 10C, 11A to 11C, and 12A to 12C show simulation results of forming photoresist patterns for an active region, the photoresist patterns having uniform pitches in accordance with embodiments of the invention. The exposure equipment used in this experiment had a numerical aperture of about 0.78 and an annular illuminator having a diameter of about0.72 mm to 0.92 mm. The photoresist pattern in FIG. 10A was formed under conditions where a focus margin was about 0.0 μm. The photoresist pattern in FIG. 10B was formed under conditions where the focus margin was about 0.1 μm. The photoresist pattern in FIG. 10C was formed under conditions where the focus margin was about 0.2 μm. As shown in FIG. 10C, even though the focus margin was about 0.2 μm, the photoresist pattern was normally formed. FIGS. 11A to 11C show photoresist patterns that were formed using an exposure mask whose sizes were shrunk by about 80% from those of the exposure masks that were used for forming the photoresist patterns in FIGS. 10A to 10C. The photoresist pattern in FIG. 11A was formed under conditions where a focus margin was about 0.0 μm. The photoresist pattern in FIG. 11B was formed under conditions where the focus margin was about 0.1 μm. The photoresist pattern in FIG. 11C was formed under conditions where the focus margin was about 0.2 μm. As shown in FIG. 11C, even though the focus margin was about 0.2 μm, the photoresist pattern was normally formed. Also, FIGS. 12A to 12C show photoresist patterns that were formed using exposure masks whose sizes were shrunk by about 65% from those of the exposure masks that were used for forming the photoresist patterns in FIGS. 10A to 10C. The photoresist pattern in FIG. 12B was formed under conditions where a focus margin was about 0.1 μm. As shown in FIG. 12B, even though the focus margin was about 0.1 μm, the photoresist pattern was normally formed. From the above experimental results, it should be noted that, because the focus margin is increased when the pitches are uniform, it is easy to normally form the active photoresist pattern and the ability to shrink the resulting pattern is thereby increased. FIGS. 13A and 13B show simulation results of forming photoresist patterns for a contact, the photoresist patterns formed using a conventional exposure mask having non-uniform pitches. In FIGS. 13A and 13B, squares represent contact patterns on an exposure mask, and circles represent photoresist patterns for contacts to be formed by an exposure process. The exposure equipment used in this simulation had a numerical aperture of about 0.78 and a conventional illuminator having a diameter of about 0.8 mm. The photoresist pattern in FIG. 13A was formed under conditions where a focus margin was about 0.0 μm. The photoresist pattern in FIG. 13B was formed under conditions where the focus margin was about 0.1 μm. Although this is not represented in drawings, when the focus margin was about 0.2 μm, the photoresist pattern might not be formed. FIGS. 14A to 14C show simulation results of forming photoresist patterns for a contact hole, the photoresist patterns formed using an exposure mask having uniform pitches according to embodiments of the invention. In FIGS. 14A to 14C, squares represent contact patterns on an exposure mask, and circles represent photoresist patterns for contacts to be formed by an exposure process. The exposure equipment used in this simulation had a numerical aperture of about 0.78 and a conventional illuminator having a diameter of about 0.8 mm. The photoresist pattern in FIG. 14A was formed under conditions where a focus margin was about 0.0 μm. The photoresist pattern in FIG. 14B was formed under conditions where the focus margin was about 0.1 μm. The photoresist pattern in FIG. 14C was formed under conditions where the focus margin was about 0.2 μm. As shown in FIG. 14C, even though the focus margin was about 0.2 μm, the photoresist pattern was normally formed. FIGS. 15A to 15C show simulation results of forming contact holes that were formed in accordance with embodiments of the invention, the contact holes formed using an exposure mask on which dummy pattern were interposed to form the uniform pitches between the contact patterns. In FIGS. 15A to 15C, squares represent contact patterns on an exposure mask, and circles represent photoresist patterns for contacts to be formed by an exposure process. The exposure equipment used in this simulation had a numerical aperture of about 0.78 and a conventional illuminator having a diameter of about 0.8 mm. The photoresist pattern in FIG. 15A was formed under conditions where a focus margin was about 0.0 μm. The photoresist pattern in FIG. 15B was formed under conditions where the focus margin was about 0.1 μm. The photoresist pattern in FIG. 15C was formed under conditions where the focus margin was about 0.2 μm. As shown in FIG. 15C, even though the focus margin was any one of 0.0 μm to 0.2 μm, the photoresist pattern for contacts was normally and uniformly formed. Thus, according to embodiments of the invention, a semiconductor device having an increased margin of a photolithography process may be manufactured, and the resulting semiconductor device may be highly integrated by shrinking a cell size of the semiconductor device. The invention may be practiced in many ways. What follows are exemplary, non-limiting descriptions of some embodiments of the invention. A semiconductor device in accordance with some embodiments of the invention includes a P type impurity region and an N type impurity region provided on a substrate, active patterns, and gate patterns. The active patterns are disposed to have a first pitch from each other in the P type and N type impurity regions. The gate patterns are disposed in a direction substantially perpendicular to and on the active patterns to have a second pitch between them. In a method of manufacturing a semiconductor device in accordance with other embodiments of the invention, a substrate doped with a P type impurity is provided. An N type impurity is doped into the substrate to divide the substrate into a P type impurity region and an N type impurity region. Active patterns having a first pitch are formed in the P type and N type impurity regions. Gate patterns having a second pitch are formed in a direction substantially perpendicular to the active patterns and on the active patterns. An SRAM device in accordance with other embodiments of the invention includes an N type well and a P type well provided on a substrate. Active patterns having a first pitch are disposed in the N type and P type wells. Gate patterns having a second pitch are disposed in a direction substantially perpendicular to the active patterns and on the active patterns. In a method of manufacturing an SRAM device in accordance with still other embodiments of the invention, a substrate doped with a P type impurity is provided. An N type impurity is doped into the substrate to divide the substrate into a P type well and an N type well. Active patterns having a first pitch are formed in the P type and N type wells. Gate patterns having a second pitch are formed in a direction substantially perpendicular to the active patterns and on the active patterns. According to embodiments of the invention, a semiconductor device having an increased margin of a photolithography process may be formed. Because it is easy to shrink the cell size of such an semiconductor device, the semiconductor device may be highly integrated. Furthermore, a failure rate in manufacturing the semiconductor device on the photolithography process is reduced so that the manufacturing yield of the semiconductor device may increase. Having described preferred embodiments of the invention, it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made to the particular embodiments of the invention disclosed that are nevertheless still within the scope and the spirit of the invention as defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a semiconductor device, a method of manufacturing a semiconductor device, an SRAM device and a method of manufacturing an SRAM device. More particularly, the present invention relates to a semiconductor device, a method of manufacturing a semiconductor device, an SRAM device and a method of manufacturing an SRAM device having a sufficient process margin. 2. Description of the Related Art Generally, semiconductor memory devices may be categorized as either a dynamic random access memory (DRAM) device or a static random access memory (SRAM) device in accordance with memory type. The SRAM device has a rapid speed, low power consumption, and a simply operated structure. Accordingly, the SRAM device is currently noticed in a semiconductor memory field. Information stored in the DRAM device is periodically refreshed. A periodical refresh of information stored in the SRAM device is, however, not necessary. A typical SRAM device includes two pull-down elements, two pass elements, and two pull-up elements. The SRAM device may be classified as either a full CMOS type, a high load resistor (HLR) type, or a thin film transistor (TFT) type in accordance with the configuration of the pull-up element. A p-channel bulk MOSFET is used as the pull-up element in the full CMOS type. A polysilicon layer having a high resistance value is used as the pull-up element in the HLR type. A p-channel polysilicon TFT is used as the pull-up element in the TFT type. The SRAM device having the full CMOS type of a cell has a low standby current, and also stably operates compared to the SRAM having other types of cells. FIG. 1 is a circuit illustrating a conventional full CMOS type SRAM cell. Referring to FIG. 1 , a conventional SRAM cell includes first and second pass transistors Q 1 and Q 2 for electrically connecting first and second bit lines BL 1 and BL 2 to first and second memory cell nodes Nd 1 and Nd 2 , respectively, a PMOS type pull-up transistor Q 5 electrically connected between the first memory cell node Nd 1 and a positive supply voltage Vdd, and an NMOS type pull-down transistor Q 3 electrically connected between the first memory cell node Nd 1 and a negative supply voltage Vss. The PMOS type pull-up transistor Q 5 and the NMOS type pull-down transistor Q 3 are controlled by a signal outputted from the second memory cell node Nd 2 to thereby provide the positive supply voltage Vdd or the negative supply voltage Vss to the first memory cell node Nd 1 . The conventional SRAM cell further includes a PMOS type pull-up transistor Q 6 electrically connected between the positive supply voltage Vdd and the second memory cell node Nd 2 , and an NMOS type pull-down transistor Q 4 electrically connected between the second memory node Nd 2 and the negative supply voltage Vss. The PMOS type pull-up transistor Q 6 and the NMOS type pull-down transistor Q 4 are controlled by a signal outputted from the first memory cell node Nd 1 to thereby provide the positive supply voltage Vdd or the negative supply voltage Vss to the second memory cell node Nd 2 . The first pass transistor Q 1 , the NMOS type pull-down transistor Q 3 and the PMOS pull-up transistor Q 5 are interconnected at the first memory cell node Nd 1 . The second pass transistor Q 2 , the NMOS type pull-down transistor Q 4 and the PMOS pull-up transistor Q 6 are interconnected at the second memory cell node Nd 2 . The full CMOS type SRAM cell includes the NMOS type transistors Q 1 , Q 2 , Q 3 and Q 4 , and the PMOS type transistors Q 5 and Q 6 . When the NMOS and PMOS type transistors are disposed adjacently to each other in one cell, a latch-up and the like may occur, which causes an excessive current to flow between a positive supply voltage line and a negative supply voltage line. To prevent the occurrence of the latch-up, active patterns are disposed so that pitches between the active patterns can have more than two sizes. Namely, in such arrangement of the active patterns, a pitch between an active pattern in which the PMOS type transistor is formed and an active pattern in which the NMOS type transistor is formed is relatively [more] lengthened to perform an entirely elemental isolation between the PMOS and NMOS transistors. On the contrary, a pitch between active patterns in which identical MOS type transistors are disposed is relatively shortened. Thus, in the conventional full CMOS type SRAM cell, since the pitches between the active patterns have more than two sizes that are different from each other, pitches between patterns and pitches between contacts formed on the active pattern, respectively, are also more than two sizes. When the pitches between the patterns formed by the same process are varied as described above, a margin of a photolithography process for forming the patterns is determined based on the minimal one of the pitches between the patterns. Accordingly, the process margin is greatly decreased so that a probability of failures in forming the patterns may be high. Furthermore, it may be difficult to manufacture a highly-integrated semiconductor device by shrinking a cell size of the semiconductor device. Embodiments of the invention address these and other disadvantages of the conventional art. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a semiconductor device having an increased margin of a photolithography process. The present invention also provides a method of manufacturing a semiconductor device having an increased margin of a photolithography process. The present invention still also provides an SRAM device having an increased margin of a photolithography process. The present invention still also provides a method of manufacturing an SRAM device having an increased margin of a photolithography process. | 20040715 | 20070522 | 20050120 | 63418.0 | 2 | PIZARRO CRESPO, MARCOS D | SEMICONDUCTOR DEVICE HAVING SUFFICIENT PROCESS MARGIN AND METHOD OF FORMING SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,892,607 | ACCEPTED | Insertion/deployment catheter system for intrafallopian contraception | Contraceptive methods, systems, and devices generally improve the ease, speed, and reliability with which a contraceptive device can be deployed transcervically into an ostium of a fallopian tube. A distal portion of the contraceptive device can function as a guidewire. The proximal portion may remain in a small profile configuration while a sheath is withdrawn proximally, and is thereafter expanded to a large profile configuration engaging the surrounding tissues. | 1. A contraceptive method comprising: guiding a contraceptive device distally into an ostium of a fallopian tube wherein a sheath covers the contraceptive device; uncovering the contraceptive device by withdrawing the sheath from the contraceptive device; and releasing the uncovered contraceptive device so that the contraceptive device inhibits conception. 2. The method of claim 1, wherein the contraceptive device comprises an axially elongate flexible structure, and further comprising supporting the axially elongate flexible structure with the surrounding sheath during the guiding step. 3. The method of claim 2, further comprising supporting at least a portion of the axially elongate flexible structure with a core support disposed within an axially oriented lumen of the axially elongate flexible structure during the guiding step. 4. The method of claim 3, further comprising removing the core support during the releasing step. 5. The method of claim 1, further comprising maneuvering the contraceptive device into the ostium while the contraceptive device flexes laterally to track through the uterotubal junction. 6. The method of claim 1, further comprising positioning the contraceptive device across the muscular isthmus of the uterotubal junction. 7. The method of claim 1, further comprising avoiding perforation of the fallopian tube and facilitating tubal navigation of the fallopian tube with a distal ball tip of a distal portion of the contraceptive device, the ball tip having a diameter in a range from about 0.020 to about 0.050 inches. 8. A contraceptive method comprising: inserting a contraceptive device distally into an ostium of a fallopian tube; uncovering the inserted contraceptive device by withdrawing a sheath from around the contraceptive device; maintaining an expandable structure of the contraceptive device in a small profile configuration during the uncovering step so as to avoid restricting movement of the sheath during the withdrawing step; radially expanding the uncovered expandable structure to a large profile configuration so as to affix the contraceptive device within the ostium; and releasing the uncovered contraceptive device so that the contraceptive device inhibits contraception. 9. The contraceptive method of claim 8, wherein the expandable structure is maintained in the small profile configuration by sustaining a restraint on the expandable structure between a first elongate body extending from a proximal handle to the expandable structure and a second elongate body extending from the proximal handle to the contraceptive device, whereby the restraint is releasable so as to expand the exposed expandable structure from the proximal handle. 10. The contraceptive method of claim 9, wherein the first and second elongate bodies sustain a wind-down torque on the expandable structure, the radially expanding step comprising actuating the proximal handle so as to release a proximal end of the expandable structure relative to a distal end of the expandable structure, and so that the expandable portion unwinds and expands. 11. The contraceptive method of claim 12, wherein the wind-down torque twists the first elongate body in a first direction, and wherein the releasing step comprises rotating the first elongate body in a second direction opposite the first direction to decouple the first elongate body from the contraceptive device. 12. A contraceptive method comprising: guiding a contraceptive device distally into an ostium of a fallopian tube of a patient body wherein a sheath supports the contraceptive device, the contraceptive device comprising an elongate flexible structure; uncovering the contraceptive device by withdrawing the sheath while maintaining an expandable structure of the proximal portion in a small profile configuration with a wind-down torque between first and second elongate bodies so as to avoid restricting movement of the sheath; radially expanding the uncovered expandable structure to a large profile configuration so as to affix the contraceptive device within the ostium by actuating a proximal handle disposed outside the patient body, the proximal handle coupling proximal ends of the elongate bodies, so that the expandable portion unwinds and expands; and releasing the uncovered contraceptive device so that the contraceptive device inhibits conception by rotating the first elongate body in a direction opposite the direction of the wind-down torque to decouple the first elongate body from the contraceptive device, and by removing a core support extending into an axial lumen of the contraceptive device. 13-25. (cancelled) | CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of priority from U.S. Provisional Patent Application Ser. No. 60/150,521 filed on Aug. 23, 1999, the full disclosure of which is incorporated herein by reference. The subject matter of this application is related to that of U.S. patent application Ser. No. ______, filed concurrently herewith for a “Deployment Actuation System for Intrafallopian Contraception”, (Attorney Docket No. 16355-003910US), the full disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION The present invention generally relates to contraception and/or sterilization, and more particularly to temporary or permanent intrafallopian contraceptive devices, delivery systems, and non-surgical methods for their deployment. While the theoretical effectiveness of existing non-surgical contraceptive techniques, including barrier methods and hormonal therapies, is well established, the actual effectiveness of most known methods is disappointing. One reason for these disappointing results is that many of the presently available methods for inhibiting pregnancy without surgery depend upon significant user involvement. Non-compliance typically results in quite high rates of failure, and overcoming user non-compliance to improve overall efficacy has proven quite difficult. One form of long term contraception which is less susceptible to user non-compliance is the intrauterine device (IUD). IUDs have been found to have higher rates of reliability, and are effective for a longer period of time, then most other commercially available contraceptives. Unfortunately, IUDs are also associated with serious infectious complications. For this reason, the use of IUDs within the United States has decreased dramatically. Additionally, IUDs are subject to unplanned expulsion, and are removed due to excessive pain or bleeding in a significant percentage of cases, further reducing acceptance of the IUD as a method of inhibiting pregnancy. Commercially available options for permanent sterilization include fallopian tube ligation and vasectomy. These methods are surgical and are not available to many people in the world. It is common knowledge that fertilization occurs in the fallopian tubes where the sperm and ovum meet. Tubal ligation avoids this by surgical and complete occlusion of the fallopian tubes. In work done in connection with the present invention, it has previously been proposed to transcervically introduce a resilient coil into a fallopian tube so as to inhibit conception. PCT Patent Application No. 99/15116, assigned to the present assignee (the full disclosure of which is incorporated herein by reference) describes devices which are transcervically inserted into a tubal ostium and mechanically anchored within the fallopian tube. The described devices may promote a tissue ingrowth network to provide long term conception and/or permanent sterilization without the need for surgical procedures, and should avoid the risks of increased bleeding, pain, and infection associated with intrauterine devices. While the recently proposed intrafallopian contraceptive devices represent a significant advancement in the art, still further improvements would be desirable. In general, it would be desirable to provide improved non-surgical devices, systems, and methods for inhibiting pregnancy. It would be beneficial if these improved techniques increased the ease with which these contraceptive devices could be deployed, and if the improvements further enhanced the long term retention of the contraceptive device once it has been deployed. It would be further beneficial if these improved access and deployment techniques were suitable for a wide variety of physiological geometries, ideally without having to tailor the device, deployment system, or deployment method for specific individuals. Some or all of these advantages are provided by the devices and methods described hereinbelow. SUMMARY OF THE INVENTION The present invention generally provides improved contraceptive and/or sterilization methods, systems, and devices. The invention generally improves the ease, speed, and reliability with which a contraceptive device can be deployed transcervically into an ostium of a fallopian tube. In many embodiments, a distal portion of the contraceptive device will function as a guidewire, facilitating advancement of the device (and the deployment system) into the tubal ostium. Typically, a proximal portion of the device will remain covered by a deployment sheath until the device is in position. Thereafter, the sheath can be withdrawn proximally, exposing a surface which is well adapted for retaining the device within the tube and/or uterotubal junction (but which would not be ideal for facilitating advancement of the device if left unsheathed during positioning). In the exemplary embodiment, the proximal portion remains in a small profile configuration while the sheath is withdrawn proximally, and is thereafter expanded to a large profile configuration engaging the surrounding tissues. Actuation may be affected after withdrawal of the sheath by a variety of mechanisms, ideally by restraining a helical coil of the proximal portion using first and second elongate bodies. Releasing one of the bodies relative to the other can release the exposed helical coil to expand resiliently. The released helical coil can safely engage and anchor the contraceptive device within a wide variety of physiological tissue geometries. Using the distal end of the contraceptive device as a guidewire avoids the complexity of multiple step deployments (which might otherwise involve separate guidewire access, catheter access, and advancement of the device), while still providing a smooth, easily advanced outer system profile. In a first aspect, the invention provides a contraceptive method comprising guiding a contraceptive device distally into an ostium of a fallopian tube with an exposed distal portion of the contraceptive device while a sheath covers a proximal portion of the contraceptive device. The proximal portion of the guided contraceptive device is uncovered by withdrawing a sheath proximally from the proximal portion. The uncovered contraceptive device is released so that the contraceptive device inhibits conception. Typically, the contraceptive device comprises an axially elongate flexible structure. Advantageously, the proximal portion of this flexible structure can be supported by the surrounding sheath while the distal portion is acting as a guidewire. Often times, at least a portion of the exposed distal portion can be supported with a core support (for example, a removable core wire) disposed within an axially oriented lumen of the contraceptive device. Preferably, the distal portion will flex laterally to track through the uterotubal junction so that the contraceptive device is positioned across the muscular lumen narrowing adjacent of the uterotubal junction. A distal ball tip having a diameter in a range from about 0.020 inches to 0.050 inches can help avoid perforation and facilitate tubal navigation. In another aspect, the invention provides a contraceptive method comprising inserting a contraceptive device distally into an ostium of a fallopian tube. A proximal portion of the inserted contraceptive device is uncovered by withdrawing a sheath from around the proximal portion. An expandable structure of the proximal portion is maintained in a small profile configuration during the uncovering step so as to avoid restricting movement of the sheath while the sheath is withdrawn. The uncovered expandable structure is radially expanded to a large profile configuration so as to affix the contraceptive device within the ostium. The uncovered contraceptive device is released so that the contraceptive device inhibits conception. Preferably, the expandable portion is maintained in the small profile configuration using a restraining force or torque. This restraint can be transmitted proximally using a first elongate body and a second elongate body. Typically, the first and second elongate bodies sustain a wind-down torque on the expandable structure. The expandable structure can be expanded by actuating the proximal handle so as to rotationally and/or axially release a proximal end of the elongate bodies relative to each other. In another aspect, the invention provides a contraceptive system comprising an intrafallopian contraceptive device having a proximal portion adjacent a proximal end and a distal portion adjacent a distal end. The distal portion has a flexibility suitable to function as a guidewire. A sheath is releasably secured over the proximal portion of the contraceptive device so that the distal portion of the contraceptive device remains exposed when the contraceptive device and sheath are inserted transcervically into an ostium of the fallopian tube. A first elongate body extends from a proximal end distally into detachable engagement with the contraceptive device for withdrawing the sheath from around the inserted contraceptive device. In yet another aspect, the invention provides a contraceptive kit comprising a contraceptive device and instructions for deploying the contraceptive device. The instructions describe the method steps of guiding the contraceptive device into an ostium of a fallopian tube with a distal portion of the contraceptive device. The instructions also describe uncovering a proximal portion of the contraceptive device so that the proximal portion can restrain the contraceptive device within the ostium. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the uterine and tubal anatomy for deployment of the contraceptive devices of the present invention. FIG. 1A schematically illustrates method steps for an exemplary contraceptive device deployment method. FIG. 1B is a partial cut-away side view of a contraceptive system according to the principles of the present invention. FIG. 2 is a side view of a removable core wire of the contraceptive system of FIG. 1B. FIG. 3 is a contraceptive device of the contraceptive system of FIG. 1B, in which an outer helical coil is in a large profile configuration. FIG. 3A is an end view of the contraceptive device of FIG. 3. FIG. 3B illustrates a contraceptive device having a tubular band for smoothly disengaging a release pin of a release catheter. FIG. 4 is a side cross-section of a distal end of a delivery catheter of the contraceptive system of FIG. 1B. FIG. 4A is an axial cross-sectional view of the delivery catheter of FIG. 4. FIG. 5 is an axial cross-sectional view of an outer sheath of the delivery system of FIG. 1B. FIGS. 5A through 5F illustrate sheaths having positioning surfaces for axially positioning the contraceptive device relative to the tubal ostium. FIG. 6 is a partial cut-away view showing engagement between the outer helical coil of the contraceptive device and the release catheter so as to maintain the wind-down torque on the outer helical coil. FIG. 7 schematically illustrates a contraceptive kit according to the principles of the present invention. FIGS. 8, 8A, 8A1, 8A2, 8B, 8B1, 8B2, 8C, 8C1, and 8D are illustrations schematically showing a method for deploying a contraceptive device using the system of FIG. 1A. FIG. 9 illustrates an alternative deployment method using an alternative imaging system. FIG. 10 schematically illustrates a side view of alternative distal components for a contraceptive system. FIGS. 11A and 11B illustrate alternative coupling structures at a proximal end of an outer helical coil, the coil couplers adapted to releasably maintain torque on the coil in cooperation with a release catheter. FIG. 12 is a partial cut-away view of a proximal end of a primary coil showing an alternative threaded connector for coupling the primary coil to a core wire. FIG. 13 is a schematic illustration of an alternative core wire structure having a threaded connector suitable for engagement with the primary coil connector of FIG. 12. FIG. 14 schematically illustrates a release catheter suitable for releasably maintaining torque in cooperation with the connectors of FIGS. 11A and 11B. FIG. 15 schematically illustrates a separate positioning catheter slidably disposed over the sheath for axially positioning the contraceptive device. FIGS. 16A and 16B are end views of alternative embodiments of an integrated release catheter/sheath for both maintaining a wind-down torque on, and being slidably disposed over, an expandable outer coil. FIG. 17 schematically illustrates a tool and method for loading a radially expandable contraceptive device into a combination release catheter/sheath. FIG. 18 illustrates a method for using a positioning surface of a sheath or positioning catheter. FIG. 19 illustrates an alternative outer sheath structure. FIG. 20 schematically illustrates an optional proximal handle to facilitate coordinated movement of the structures of the delivery system. DESCRIPTION OF THE SPECIFIC EMBODIMENTS The present invention provides a contraceptive device, system, and method which can be used to inhibit pregnancy, typically for the long-term inhibition of pregnancy, and often providing permanent contraception or sterilization. By introducing at least a portion of these contraceptive devices into an ostium of a fallopian tube, the risks of unplanned expulsion, pelvic pain, and infectious complications may be significantly reduced. Although the present invention may be included within a group of contraceptive techniques generally referred to as fallopian tube occlusion methods, the invention need not be advanced fully into the fallopian tube, and in some embodiments, need not fully block the tubal lumen to effectively disrupt fertilization. As described in U.S. patent application Ser. No. 09/324,078, assigned to the present assignee (the full disclosure of which is incorporated herein by reference), contraception may optionally be provided by fully occluding the tubal lumen, and/or by sufficiently disrupting the fertilization process without total occlusion. In some embodiments, including a bioactive material such as copper may enhance the device's effectiveness. As used herein, a structure is inserted “within a tubal ostium” whenever the structure is advanced from the uterus into (and optionally beyond) the tubal ostium, the uterotubal junction, and/or the fallopian tubes. Referring now to FIG. 1, access to uterus U will generally be gained through cervix C. From within uterus U, fallopian tubes F are accessed via tubal ostia O. Fallopian tubes F generally include three segments between ostium O and the fimbria FIM. Beginning adjacent uterus U, the intramural segment INT of fallopian tubes F are surrounded by the muscular uterine tissues. Beginning at uterotubal junction UTJ, fallopian tubes F extend beyond the uterine tissues and within the peritoneal cavity along an isthmic segment ISC, and then along an ampullary segment AMP. In general, the ideal placement for the intrafallopian contraceptive devices of the present invention is spanning the intramural INT to isthmic ISC portion of the fallopian tube. Where a radially expandable attachment mechanism such as an outer coil is included on the intrafallopian contraceptive device, that expandable or anchoring structure will preferably span the uterotubal junction UTJ. It should be noted that the uterotubal junction UTJ may be defined as the plane where the fallopian tube meets the peritoneal cavity. It should also be noted that the narrowest portion of the fallopian tube need not necessarily be disposed in the isthmic segment ISC, particularly once the contraceptive fallopian device (often having a radially expandable anchoring structure) is deployed therein. In fact, work in connection with the present invention has shown that the effectively narrowest portion of the tube may be at or adjacent the uterotubal junction UTJ. Referring now to FIG. 1A, an overview of an exemplary method 2 for deploying and using the contraceptive devices of the present invention is helpful to understand the selection of structures used in those devices. It should be understood that not all steps need be performed in every deployment. Nonetheless, reviewing the exemplary deployment method 2 will help to understand the structures described hereinbelow. Identification of the anatomy and target location 3 allows the operator to determine the preferred placement of the contraceptive device within the ostium, and also to determine if any special circumstances are present for a particular device placement procedure. Anatomy and target location identification can be facilitated using a variety of known visualization modes, including hysteroscopy, sonography (ultrasound), fluoroscopy, and the like. Hence, an exemplary contraceptive device may be adapted to delivery using more than one imaging modality. The exemplary contraceptive device will also preferably be able to accommodate a wide variety of anatomies. Two factors contribute to the importance of this variability: First, a wide variation may be observed between tubal anatomies of differing patients. Secondly, it can be quite difficult to determine and identify the specific tubal anatomy of a particular patient. As a result, the preferred contraceptive device may incorporate safeguards allowing sufficiently accurate placement (with tolerance for normal operator error), as well as for the variance in the length and diameter of the various segments of the fallopian tube. Exemplary deployment method 2 in FIG. 1A will also include positioning of the device at the target location 4. Once again, a wide variety of techniques might be used to assist a healthcare professional in positioning the device in the correct location, including visualization techniques, providing high-contrast markers (such as radiopaque markers, echogenic markers, or the like), providing tactile indication of the placement position by including physical stops or “bumpers” (which may be adapted to engage reference tissues in such a tactile way as to send a signal to the healthcare professional), or the like. Device positioning can be significantly facilitated by providing an appropriate device and/or deployment system design having the proper flexibility, navigation characteristics, friction reduction surfaces, small delivery profile, coatings, and the like. Once again, device positioning 4 will preferably compensate for anatomical variations, operator error, and difficulties in visualization so as to help promote accurate placement. In the exemplary deployment method 2, the device is deployed and/or expanded at the target location in the step indicated by reference numeral 5. Optionally, the device and/or deployment system may allow visualization and/or confirmation of device expansion while expansion takes place. Generally, the contraceptive device will be detached from its deployment system at the target location in step 6. Once again, it is helpful to provide visualization and/or confirmation of detachment, which may be provided visually, via ultrasound, fluoroscopy, or the like. It should be understood that a wide variety of detachment mechanisms might be used to decouple the device from the deployment system. In the exemplary method, it should be possible to confirm the position of the device at the target location 7. Confirmation may be provided, once again, by visualizing at least a portion of the device after detachment, often using the same visualization modality used during placement. In addition to optical visualization techniques, this may be provided by including radiopaque markers for fluoroscopic placement confirmation, sonographic markers for ultrasound placement confirmation, or the like. Optionally, specific marker locations may be provided along the contraceptive device 2, for example, to indicate the specific locations of proximal and/or distal ends of the device. Exemplary method 2 further includes a step 9 for anchoring and stability of the device at the target location. Aspects of this step include accommodating visualization of the device so as to monitor it's stability. Anchoring of the device at the target location may include anchoring on an acute basis (such as using an expanded helical coil that can adjust and adapt to variations in the tubal lumen, an expanded stent-like structure, expanded braid, or the like) and long-term (such as may be provided by including a fiber mesh or lattice which incites a tissue reaction such as ingrowth, thereby providing fibrous tissues which affix the device in place within the fallopian tube). Similarly, stability will preferably be provided for both a short-term and a long-term, typically by designing a device with the proper resiliency and shape to accommodate physiological movement without shifting. The device will preferably be wear-profile balanced to provide sufficient anchoring without inducing pain or losing its stability due to erosion for the life of the patient. The final step indicated on the exemplary method 2 of FIG. 1A is efficacy. This may be provided by incorporating a lumen/space filling design that sufficiently alters the function and architecture of the fallopian tube so as to inhibit conception. This may include the use of polyester fibers or the like to incite the desired tissue reaction. In general, the devices of the present invention may be adapted to incite a reaction tissue response in the fallopian tube through the presence polyester fibers, or the like. Ideally, this reaction can be classified as a highly localized, benign tissue reaction. The reaction results in the incorporation of the contraceptive device into the tubal lumen tissues, so that the device is firmly embedded into the surrounding tissue structure. This reaction can typically be characterized by the proliferation of smooth muscle cells and associated fibrosis. Additionally, the tubal lumen will generally exhibit an absence of the normal tubal architecture which is generally necessary for conception. The tubal lumen may also be obstructed, occluded, and/or functionally occluded by the presence of the device and associated fibrosis sufficiently to inhibit conception. The reaction is a benign one, and there appears to be no change in anatomy or structure of the outer tubal wall beyond approximately 5 to 10 mm radially outwardly from the outer coil of the device. Similarly, normal tubal architecture will often be visible about 5 mm axially beyond the device (typically distal of the device, as the device often extends into the uterus), again indicating a very localized reaction. Referring now to FIG. 1B, an exemplary contraceptive system 10 generally includes a contraceptive device 12, a sheath 14 partially surrounding the contraceptive device, a release catheter 16, and a core shaft 18. Contraceptive device 12 generally has a proximal portion 20 adjacent a proximal end 22 (disposed within sheath 14), and a distal portion 24 adjacent a distal end 26 (which are exposed beyond the distal end of sheath 14). Distal portion 24 generally functions as a distal guidewire while system 10 is advanced within the tubal ostium. Proximal portion 20 includes a radially expandable structure which can be expanded after sheath 14 is withdrawn so as to affix the contraceptive device in the deployed position. Sheath 14 is generally a tubular structure having a distal end 28 and extending proximally to a proximal housing 30. Sheath 14 will generally have a length in a range from about 25 to about 50 cm, and will typically have an outer diameter in a range from about 0.020 to about 0.060 inches, the exemplary sheath having a length of about 39.5 cm and an outer diameter of about 0.04 inches. The inner diameter of sheath 14 may be in a range from about 0.02 inches to about 0.05 inches, with the exemplary sheath having an inner diameter of about 0.033 inches. Proximal housing 30 includes a side arm with an injection port to allow infusion of fluids for patency checks, delivery of local anesthetic, or the like. Proximal housing 30 also includes a Touhy-Borst valve 32 releasably securing sheath 14 to release catheter 16. Release catheter 16 generally comprises a tube having a distal end 34 which releasably engages contraceptive device 12, and a proximal end adjacent a proximal fitting 36. Release catheter 16 will generally be longer than sheath 14, and fitting 36 will include another Touhy-Borst valve releasably securing release catheter 16 to core shaft 18. The release catheter length is sufficiently longer than the sheath 14 so that full retraction of the sheath exposes the distal end of the release catheter, thereby allowing the release of the expandable structure upon movement of the release catheter to be hysteroscopically monitored. It should be understood that the Touhy-Borst valve may be replaced by any coupling structure which inhibits axial and rotational movement between the coupled devices, such as a key-slot arrangement or the like. In the exemplary embodiment, core shaft 18 comprises a resilient tapering structure extending from within distal portion 24 of contraceptive device 12 proximally through fitting 36 of release catheter 16 to a proximal handle 38. Core shaft 18 threadably engages contraceptive device 12 proximally of distal end 28 of sheath 14 before deployment. In the exemplary embodiment, core shaft 18 and release catheter 16 transmit a wind-down torque onto an expandable structure of the contraceptive device so as to maintain the expandable structure in the small profile configuration. Hence, release catheter 16 relative to releasing core shaft 18 by actuating the Touhy-Borst valve of fitting 36 allows the expandable structure to be activated independently of movement of the surrounding sheath. While exemplary contraceptive device 12 makes use of a radially expandable helical coil to help restrain the structure during tissue ingrowth, a wide variety of mechanical and other restraint mechanisms might be included. For example, alternative mechanical anchors might be attached to the device, such as resilient coils biased to form bends, loops, and/or other secondary shapes having enhanced cross-sections, slotted tubes, Malecot-type structures, radially expandable braids, stent-like devices, and the like. The mechanical structures may be resilient, plastically deformable, or the like, and suitable structures are described in more detail in, for example, PCT Publication No. WO 99/15116. Still further device-restraint techniques might be employed, including thermal, chemical, adhesive, and the like. These techniques can be used to avoid expulsion by increasing friction between the device and the surrounding tissues, by imposing limited tissue damage to promote scar tissue formation, and/or by promoting tissue ingrowth into the device. Thermal techniques may include, for example, transmission of electrical or laser energy along contraceptive system 10. Resistive heating of contraceptive device 10 might be effected by applying an electrical potential across the device with conductors extending along sheath 14 and release catheter 16, laser energy along an optical wave guide attached to core wire 18, or the like. Monopolar tissue desiccation might be effected via a large return electrode patch by energizing core wire 18 with radiofrequency energy, or an adhesive and/or caustic agent (such as a cyanoacrylate or silver nitrate) might be introduced via any of the lumens of the delivery system, via a dedicated lumen or structure, or the like. Biodegradable plugs and the like might also be included, and the retained structure may optionally comprise copper or other bioactive agents to help inhibit conception. Tissue reaction to the retained contraceptive device 12 can help to provide long term contraception and/or sterilization. To promote conception inhibiting tissue reaction, device 12 will often include a tissue reaction material, the material often comprising fibers. The fibers may comprise a polyester, such as Dacron® polyesters, silk, nylon, or the like. The fibers may be in the form of a weave, a knit, a braid, a felt, or the like, or may comprise stands attached to the device body. The components of contraceptive system 10 can be further understood with reference to FIGS. 2 through 5, in which these components are illustrated individually. Beginning with FIG. 2, core shaft 18 tapers to a gradually increasing diameter proximally of distal end 40 so as to provide increasing support of distal portion 24, proximal portion 20, and the catheter structures proximal of contraceptive device 12. This increasing support (and the associated increase in column strength) enhances the pushability of the contraceptive system while accessing the target deployment site. Threads 42 threadingly engage a coil of the contraceptive device, and are generally formed by affixing a coil with separated windings to a central core wire at a bond 44. A tube 43 may also be affixed at bond 44 to prevent binding and/or jumping of the cooperating threads, the tube ideally comprising stainless steel, platinum, or the like. In the exemplary device, core wire 18 comprises a high strength metallic structure having a diameter in a range from about 0.003 inches to about 0.037 inches. The ideal core wire has a total length of about 65 cm between distal end 40 and proximal handle 38, while threads 42 are separated from the distal end by a distance of about 3 cm. Core wire 18 tapers from a minimum diameter of about 0.003 inches near the distal end to a diameter of about 0.011 inches adjacent threads 42, and to a maximum diameter of about 0.029 inches proximally of the threads. The exemplary core wire comprises nickel titanium, while threads 42 comprise stainless steel attached to the central wire by a bond 44 of silver tin. While the exemplary system uses threads to couple the core wire (or other deployment shaft) with the contraceptive device, a variety of alternative detachable connections might be used, including cooperating keys/slots, BNC connectors, or the like. The exemplary contraceptive device 12 is illustrated in more detail in FIG. 3. Contraceptive device 12 includes a primary coil 50 which extends from a distal ball tip 52 to proximal threads 54, which may conveniently be formed by separating the proximal windings of the primary coil. The expandable structure, here in the form of a helical outer coil 56, has a proximal end bent to form a wind-down attachment 58, and has a distal end affixed to coil 50 at coil bond 60. Fiber 62 extends between the inner and outer coils, and is also disposed within primary coil 50 so as to promote tissue ingrowth throughout the cross-section of contraceptive device 12. The arrangement of coil attachment 58 and position of fiber 62 can be seen in the axial view of FIG. 3A. By making use of a contraceptive device having a distal portion 24 which can act as a guidewire, no open lumen need be provided through the center of the contraceptive device (for example, for a separate guidewire), and multiple access/deployment steps (for example, accessing the target location with a guidewire, advancing a catheter over the guidewire, removing the guidewire from the positioned catheter, and then advancing the contraceptive device) can be avoided. A slight variation upon the wind-down attachment is illustrated in FIG. 3B. An alternative contraceptive device 12a includes a small tube or band 59 soldered within a small diameter proximal section of outer coil 56. Band 59 can have a relatively large interface area with coil 56 to facilitate bonding, avoids stress concentrations, and presents a smooth inner lumen which may inhibit binding of the release catheter. Band 59 may comprise stainless steel or platinum, ideally having an inner diameter of about 0.023 inches and an outer diameter, with the thickness of the surrounding outer coil and solder bond, of about 0.03 inches. A similar band 59′ may be disposed within threads 54 of coil 50 to provide a radiopaque marker, and to inhibit thread jump. Band 59′ may be similar in structure to band 59, but shorter in length. Still further alternative attachment mechanisms are possible. For example, a mass or knob may be formed at the proximal end of outer coil 56 from a simple ball of solder or coil material, bend, or the like, which is slidably receivable within a slot or other opening of the delivery catheter. In the exemplary embodiment, coil 50 is formed of a high strength resilient material, ideally comprising stainless steel wire having a diameter of about 0.005 inches, and wound to form a coil having an outer diameter of about 0.022 inches. Ball tip 52 preferably has a cross-section which is larger than the cross-section of coil 50, the ball tip generally having a diameter in a range from about 0.020 inches to about 0.050 inches, the exemplary ball tip having a diameter of 0.027 inches. Helical coil 56 comprises a highly elastic high strength metal which is biased to expand from the low profile configuration illustrated in FIG. 1 to the larger profile configuration illustrated in FIG. 3 when released within the target site. In the exemplary embodiment, outer coil 56 comprises a ribbon of a superelastic or shape memory alloy, and has a thickness in the range from about 0.001 inches to 0.002 inches and a width in a range from about 0.010 inches to 0.020 inches, with the ribbon being biased to form a helical coil having an outer diameter of about 0.080 inches and a length of about 3.5 cm when not otherwise restrained. Outer coil 56 is preferably fixed to primary coil 50 by a bond 60 of solder. Bond 60 will preferably be separated from ball tip 52 by a distance in a range from about 0.4 cm to about 0.7 cm. Advantageously, bond 60 may be aligned with the distal end 28 of sheath 14 so as to help present an atraumatic increase in diameter between distal portion 24 of contraceptive device 12 and the sheathed proximal portion 20 prior to deployment. Fiber 62 may comprise a polyester or the like. The fiber may be loosely woven or matted strands, with at least one end of the fibers affixed to primary coil 50 or outer coil 56. In the exemplary embodiment, fiber 62 comprises between about 20 and 70 filaments of textured PET fibers. Generally, the expandable structure will help hold contraceptive device 12 in place at least until tissue ingrowth occurs sufficiently so as to permanently retain the contraceptive device and/or may restrain the device permanently. Hence, the expandable structure will often benefit from a relatively high friction outer surface. Such an outer surface might make it difficult to advance the contraceptive device into position if the device is advanced without sheath 14. Work in connection with the present invention has shown that resiliently expandable structures which have sufficient strength to reliably hold the contraceptive device within the ostium of the fallopian tube may impose significant frictional forces against a surrounding sheath. These frictional forces can significantly complicate the accurate delivery of contraceptive device. Hence, outer coil 56 is preferably maintained in a small profile configuration within sheath 14 by applying a wind-down torque between core wire 18 and release catheter 16. The core wire can transfer the wind-down torque to outer coil 56 through cooperating threads 42, 54, with the direction of the wind-down torque preferably being arranged so that the wind-down torque discourages decoupling of the threads. In other words, rotation of core wire 18 relative to contraceptive device 12 in a direction opposed to the wind-down torque is used to detach core wire 18 from contraceptive device 12. It should be understood that a variety of alternative deployment/expansion mechanisms might be used with alternative expandable structures, such as stent-like expandable structures, braids, etc. The distal structure of release catheter 16 is shown in FIGS. 4 and 4A. The wind-down torque is releasably transferred between outer coil 56 and release catheter 16 by cooperation between bend 58 and pin 66 at the distal end 34 of the release catheter 16. Release catheter 16 generally includes a tubular body 68 formed of polyimide. Pin 66 is disposed within a lumen of tubular body 68, and is supported within the tubular body by a helical support coil 70 and adhesive 72. Pin 66 comprises a stainless steel bar having a width of about 0.008 inches, a thickness of about 0.003 inches, and a total length of about 1 cm, and extends distally from distal end 34 by a distance of about 3 mm. Support coil 70 also comprises stainless steel, and the support coil and pin 70 are bonded within tubular body 68 by cyanoacrylate, with the exemplary tubular body having an inner diameter of about 0.030 inches and an outer diameter of about 0.033 inches. Interestingly, these tubular body dimensions may be driven by the wind-down torque transferred proximally by release catheter 16. Optionally, the device and/or delivery system may be adapted to facilitate visualization and/or confirmation that release is successful. For example, the outer coil may look visibly different before and after deployment due to gaps in the coil winding, or the like. Similar feedback may be provided by fluoroscopic or sonographic image changes. The structure of sheath 14 is illustrated in more detail in FIG. 5. Distal end 28 (see FIG. 5A) of sheath 14 will preferably be rounded, with the distal end ideally cooperating with coil bond 60 of contraceptive device 12 so as to avoid friction and facilitate distal navigation of delivery system 16 through the uterotubal junction and into the fallopian tube. The rounded distal end 28 may optionally be rounded along both the inner and outer diameter of sheath 14, or may primarily be rounded along the outer diameter so as to taper inwardly distally. Sheath 14 will preferably have a multi-layer structure, with the layers comprising (beginning at the outside) a hydrophilic coating 76 to reduce friction during tracking and navigation. Such hydrophilic coatings become quite slippery when exposed to fluid. Below hydrophilic coating 76 is a structural layer of a polymer 78 such as Tecoflex™ along the proximal portion of sheath 14, and a reinforcing braid 80 of a metal, ideally of stainless steel, is disposed within a layer of polyimide below polymer layer 78. Along the more distal portion of sheath 14, metal braid 82 is disposed within polymer layer 78 of Tecoflex™, or the like, and the polyimide layer is absent so as to provide enhanced flexibility. The inner lumen of sheath 14 is defined by a low friction polymer coating 84, the low friction polymer ideally comprising a PTFE such as Teflon®. Suitable sheaths 14 may be commercially available from a variety of vendors. Exemplary structures may be described in more detail in published PCT patent application WO 98/57589, the full disclosure of which is incorporated herein by reference. As schematically illustrated in FIGS. 5A through F, alternative sheaths 14A, B, and C, include bumpers 57, 57′, and 57″, respectively. Bumper 57 has an outer surface extending radially from the outer surface of the underlying sheath. Although bumper 57 may optionally provide a tactile indication that the sheath 14A is advancing distally beyond the target deployment position, it does not necessarily prevent the sheath from advancing so that the bumper can enter into the tubal ostium. Bumper 57 may also provide a visible marker that hinders pushing of the sheath so that the bumper moves past the ostium. Optionally, bumper 57 may comprise a colored adhesive, or may comprise a clear adhesive with a colored band of material disposed underneath. Alternative bumpers 57′ and 57″ may comprise polymer or metallic structures, ideally comprising a polyethylene or a super-elastic shape memory alloy. These radially expandable bumper structures can be collapsed for delivery through a working lumen of a hysteroscope, and can then expand to impede advancement of the sheath by engaging the uterine tissue adjacent to the tubal ostium. Referring now to FIG. 6, the sliding engagement between pin 66 of release catheter 16 and bend 58 of outer coil 56 is more clearly illustrated. FIG. 6 also shows how the wind-down torque imposed on the outer coil by the core shaft 18 and release catheter 16 help maintain the outer coil in a small profile configuration within sheath 14, allowing the sheath to be withdrawn easily. The wind-down torque can be released by sliding release catheter 16 so that pin 66 slides free of bend 58. Optionally, the release catheter may first be allowed to rotate relative to the core shaft to reduce the engagement forces between bend 58 and pin 66. Referring now to FIG. 7, a contraceptive kit 90 generally includes packaging 92 containing delivery system 10 and instructions for its deployment 94. Contraceptive system 10 will generally be hermetically sealed within a sterile pouch 96. Alternatively, packaging 92 may hermetically seal the contraceptive system. Instructions for use 94 will describe method steps for deployment of the contraceptive system, as described herein. The instructions for use may comprise printed material, and/or may optionally include machine-readable code (such as a CD ROM, floppy disk, or the like) and/or graphical information (such as a video tape). In some embodiments, the instructions for use may at least in part be incorporated into packaging 92 or sterile pouch 96. An exemplary method for use of contraceptive system 10 can be understood with reference to FIGS. 8 through 8D. System 10 is introduced transcervically through uterus U, generally under optical direction. Using hysteroscope S the physician directs the distal end of the system toward ostium O of fallopian tube F. Alternatively, some or all of the procedure may be performed under any medical imaging modality, including fluoroscopy, sonography, computer tomography, or the like. Uterus U may be irrigated using scope S and/or a separate irrigation system. Once ostium O is located and the scope S is oriented toward the ostium, system 10 is advanced distally through the working lumen of the scope and through the ostium and into the fallopian tube using distal portion 24 of the contraceptive device as a guidewire, while the remainder of the contraceptive device remains covered by sheath 14. The outer hydrophilic coating of sheath 14 minimizes friction while advancing system 10, and the sheath also provides structural column strength to the system. The distal ball tip of distal portion 24 aids tracking and navigation through fallopian tube F, while the primary coil structure flexes laterally to track the tortuous bends often found within the fallopian tube. In the exemplary embodiment, core wire 18 extends into distal portion 24 to enhance column strength of the distal portion beyond sheath 14, but does not extend to the ball tip. Hence, the stiffness of distal portion 24 increases proximally, further enhancing the distal portion's ability to track the lumen. In the exemplary embodiment, sheath 14 includes a visual marker 98 which can be seen from the scope of hysteroscope S (see FIG. 8B). Marker 98 will preferably be positioned partially within ostium O and partially within uterus U, thereby indicating that contraceptive device 12 is disposed at the target position, as the sheath, core shaft, and contraceptive device are releasably locked together during advancement and positioning. As described above, marker 98 may comprise a bumper, a structure which extends radially from the sheath to provide a tactile position indication. Preferred positioning of contraceptive device 12 is illustrated in FIG. 8B. Preferably, device 12 extends along the uterotubal junction UTJ, with the device ideally extending both proximally and distally of the uterotubal junction. The uterotubal junction UTJ typically has a length in a range from about 1 to about 2 cm, and outer coil 56 will preferably extend proximally beyond ostium O into uterus U by a distance in a range from about 0.5 to about 1.0 cm. Outer coil 56 will preferably extend distally of the uterotubal junction UTJ by a distance of at least 0.6 cm. Ideally, outer coil 56 will extend both proximally and distally of the plane of the uterotubal junction UTJ by a distance of at least about 0.275 inches. Extending the expandable structure both distally and proximally of this effective isthmus can provide anchoring proximally and distally of the isthmus, thereby avoiding movement of contraceptive device 12 from the target position while tissue ingrowth takes place. Advantageously, positioning accuracy with a range of about 1 cm may be provided by limiting marker 98 to a 1 cm length. This provides a sufficient positional tolerance for ease of use while helping to ensure reliable, well-anchored deployments. Referring now to FIGS. 8A, 8A1, and 8A2, positioned contraceptive device 12 is deployed by first withdrawing sheath 14 from over the expandable structure. Touhy-Borst valve 32 of proximal housing 30 is actuated to allow sliding movement between sheath 14 and release catheter 16, and the proximal housing slides proximally along the release catheter while maintaining fitting 36 of the release catheter in a fixed position, as illustrated in FIG. 8A2. Advantageously, core shaft 18 and release catheter 16 remain locked together by fitting 36, so that the expandable structure does not impede proximal movement of the sheath. Retraction of sheath 14 from the positioned (but as yet unexpanded) device 12 leaves the distal end of deployment system 10 in the configuration illustrated in FIG. 8B. Advantageously, it may still be possible to adjust the position of the device while viewing a proximal portion of outer coil 56. As can be understood with reference to FIGS. 8B and 8B1, once proximal housing 30 engages fitting 36, the Touhy-Borst valve of the fitting can be actuated so as to allow movement between core shaft 18 and release catheter 16. The core shaft and/or release catheter may be allowed to rotate relative to each other to at least partially expand outer coil 56. The surgeon slides release catheter 16 proximally while holding handle 38 of core shaft 18 in a fixed position, as shown in FIG. 8B2, thereby disengaging the release catheter from the outer coil and allowing the outer coil to expand fully and firmly attaching contraceptive device 12 to the surrounding tissue, as seen in FIG. 8C. Referring now to FIG. 8C1, to fully release contraceptive device 12 from the remaining components of delivery system 10, core shaft 18 is rotated to disengage the threaded coupling 42 between the core shaft and the contraceptive device. As described above, the direction of rotation of the core shaft for disengagement will be opposite that imposed by the wind-down torque, so that the wind-down torque helps maintain the threaded engagement prior to release of the core shaft relative to release catheter 16. Once core shaft 18 is unthreaded from contraceptive device 12, the core shaft and other delivery components can be withdrawn proximally into scope S, as shown in FIG. 8D. Scope S can view outer coil 56 to verify that the amount of the coil extending proximally of the ostium is within an acceptable range (and hence that device 12 is disposed at the target position) and the scope can be withdrawn after visually verifying that the deployment has been successful. Referring now to FIG. 9, a variety of alternative deployment methods might be used to deploy the contraceptive system 10. For example, using a simple cervical catheter 102, deployment might be directed sonographically, fluoroscopically, under magnetic resonance imaging, and possibly even solely from tactile information. In the alternative exemplary method illustrated in FIG. 9, a balloon 104 of cervical catheter 102 is inflated via inflation port 106. This allows the uterus U to be distended by introduction of distention media through a uterine catheter 108 inserted through the working lumen of cervical catheter 102. Preferably, anatomy and target location identification, device positioning, deployment, detachment, and position confirmation (as outlined in method 2 with reference to FIG. 1A) is performed under the guidance of ultrasound and/or fluoroscopic imaging. Relevant uterine catheter manipulation structures and methods are described in U.S. Pat. Nos. 5,346,498; and 5,389,100, the full disclosure of which are incorporated herein by reference. As described above, the delivery systems of the present invention will often hold the contraceptive device in a fixed position while the contraceptive device is uncovered, expanded, and/or released. When moving, for example, outer sheath 14 so as to expose the proximal portion of the contraceptive device, friction between the outer sheath and the surrounding hysteroscope (or other introducing structure, surrounding tissue, or the like) may cause inadvertent movement of the contraceptive device. To avoid such inadvertent movement, an outer sleeve may be slidably disposed around outer sheath 14. The sleeve provides a sliding interface between the sheath and surrounding structures. By axially coupling the sleeve and core shaft 18, friction between the sleeve and surrounding structures may inhibit movement of the contraceptive device. Such a sleeve will typically be shorter in length than sheath 14, and is more fully described in a concurrently filed application for a Deployment Actuation System for Intrafallopian Contraception, previously incorporated by reference. Referring now to FIGS. 10 and 11A, an alternative contraceptive system 150 includes a contraceptive device 152 having many of the components described above, but having an alternative wind-down outer coil connector 154 disposed at a proximal end of outer coil 56. An alternative release catheter 158 having a corresponding connector 160 for engagement with connector 154 of contraceptive device 152 again allows a wind-down torque to be released, as described above. In this embodiment, wind-down connector 160 of release catheter 158 comprises an opening which receives a protrusion 162 extending radially from a tubular band 156 of connector 154. In the exemplary embodiment, band 156 comprises a platinum tube having a length of about 2.2 mm, and is affixed to coil 56 using a solder bond. Protrusion 162 also comprises solder. Referring now to FIG. 11B, an alternative wind-down connector 164 may be affixed to a proximal end of outer coil 56 using a stainless steel ring 166, with the outer coil welded to band 156 and the stainless steel ring welded to the band over the outer coil. In this embodiment, protrusion 162′ is formed by welding a bent platinum ribbon to band 156. Band 156 may have a length of about 1.6 mm and an outer diameter of about 0.031″, while protrusion 162′ has an axial length of about 0.020″, and is formed of a ribbon having a thickness of about 0.0015″, with the ribbon being bent so as to extend about 0.04″ radially beyond band 156. Typically, protrusions 162, 162′ will extend radially a sufficient distance to extend into opening 160 of release catheter 158, with the release catheter and/or protrusion often having sufficient flexibility to allow disengagement of the wind-down connectors. Referring now to FIGS. 10, 12, and 13, contraceptive system 150 also uses alternative threaded connectors 170, 172 for engagement between primary coil 50 and core wire 18. Threaded connector 170 is affixed to primary coil 50 of contraceptive device 152 by solder, and includes first and second interleaved coils 174, with one of the interleaved coils terminating ¼ turn distally of the other to define a ¼ open-winding or thread 176. An outer tube or stopper band 178 inhibits radial displacement of the threads, particularly when the threads are engaged between core wire 18 and the stopper. Preferably, primary coil 50 comprises 0.005″ diameter 316L stainless steel wound to have an outer diameter of 0.0125″ with a 0.005″ pitch and a length of about 2.9 cm. First and second interleaved coils 174 comprise 0.0039″×0.008″ 316L stainless steel ribbon wound to have an outer diameter of about 0.0205″ and a 0.018″ pitch. Stopper 178 may comprise a platinum or PtIr band having an outer diameter of about 0.026″ and a length of about 1 mm. The stopper 178 and/or other components of at least one of the connectors coupling inner coil 50 to corewire 18 and outer coil 56 to a deployment catheter will preferably provide a high contrast imaging marker. Threaded connector 172 may similarly comprise interleaved coils 174 having differing lengths or axially positions so as to provide a ¼ turn open winding or thread, with the interleaved coils typically having more windings than used on threaded connector 170. An additional blocker coil 180 is disposed over and/or proximally of interleaved coils 174, with the coil being soldered to core wire 18, typically using a SnAg solder. Preferably, threaded connectors 170, 172 will have less than five windings engagement therebetween, more preferably having less than two engaged windings and ideally having less than a single winding of engagement. These limited engaged windings are sufficient to maintain coupling between core wire 18 and the contraceptive device so long as wind-down torque is maintained, and facilitate detachment after release of the wind-down torque by limiting the number of rotations of core wire 18, friction between the core wire and the contraceptive device, and the like. Release catheter 158 is shown in isolation in FIG. 14. The specific configuration of connector or opening 160 may vary, for example, with the opening being nearer a distal end 182 of release catheter 14 when alternative protrusion 162′ is used (rather than protrusion 162 formed of solder). Still further variations are possible, including rectangular openings or channels having differing shapes or extending axially to distal end 182. In general, coupler or opening 160 will have a circumferentially oriented surface to releasably maintain a wind-down torque by corresponding engagement with an associated connector of the contraceptive device. In the exemplary embodiment, release catheter 158 comprises an polyimide affixed to a proximal release catheter housing by an adhesive such as a Lock-Tite™ 3321 adhesive. During assembly, core wire 18 may be inserted through release catheter 158 and coupled to the contraceptive device with the outer coil 56 being wound-down over the primary coil, and the wind-down torque maintained by coupling the proximal portions of the core wire 18 and release catheter. Referring now to FIGS. 15 and 18, positioning surface 57 may optionally be affixed to sheath 14 to help axially position contraceptive device 152 across intermural region INT, as described above. Engagement between radially protruding positioning surface 57 and the uterine tissues surrounding ostium O allows initial axial positioning by taking advantage of the axially coupling of sheath 14 to contraceptive device 152. However, sheath 14 will be withdrawn proximally into scope S early-on during deployment, and it is often desirable to maintain the axially positioning of the contraceptive device at least until proximal coil 56 begins to expand radially. As schematically illustrated in FIG. 15, by affixing positioning surface 57 (which may optionally comprise any of the alternative positioning surface configurations described hereinabove, or still further alternative structures such as radially expandable torroidal balloons, or the like) at a distal end of a separate positioning catheter 184 slidably disposed over sheath 14, the axial positioning provided by the positioning surface may be maintained during and/or after withdrawal of sheath 14. Optionally, a proximal portion of release catheter 184 may be axially coupled to a proximal portion of release catheter 16, core wire 18, or another of the axially elongate structures so as to maintain an axial position of contraceptive device 152 using positioning surface 57. Alternatively, the positioning surface may be movable independently of these structures. Still further structures and methods for releasably restraining the proximal, radially expandable portion of the contraceptive device might be provided, as can be understood with reference to FIGS. 16A, 16B, and 17. FIGS. 16A and 16B each illustrate a distal end of an integrated sheath/release catheter 186, 188 having an axially channel 190 defining a circumferentially oriented channel surface. Channel 190 cooperates with a protrusion 162 of connector 154 so as maintain wind-down torque on the radially expandable proximal coil of contraceptive device 152 via cooperation between core wire 18 and the integrated release catheter/sheath. Additionally, the integrated release catheter/sheath slidingly surrounds the proximal, radially expandable portion of contraceptive device 152 so as to facilitate insertion of the device into the fallopian tube. As illustrated in FIG. 17, a tubular tool 192 having a lumen (which receives the contraceptive device) and a notch 194 (which receives protrusion 162) may facilitate winding-down proximal coil 56 and insertion of the proximal coil into the integrated release catheter/sheath, particularly if the tool has an outer diameter sufficiently to allow introduction of the tool into the lumen over the contraceptive device. Channel 190 will generally have a length sufficient so as to allow an integrated release catheter/sheath to slide axially from over protrusion 162 and over the outer coil 56, typically having a length of about 2.5 cms. Channel 190 may be formed during fabrication of the tubular sheath structure as shown in FIG. 16A, or may be defined by structures (such as a stainless steel, or NiTi ribbon) affixed within the lumen using an adhesive, a supporting coil, and/or the like. Referring now to FIG. 19, an alternative outer sheath 214 may be used in place of outer sheath 14 in the system of FIG. 1B. Sheath 214 has a proximal portion 216 with a relatively stiff, thicker-walled tubular structure, such as a PeBax® polymer tube having an outer diameter of about 0.062″, and an inner diameter of about 0.042″. A distal portion of sheath 14 includes an inner tube 218 of a low friction polymer and an outer tube 220 of a polymer, (such as carbothane® 73A) with at least one ribbon coil 222 therebetween. Inner tube 218 may comprise a PTFE (such as a Teflon™ material) with an inner diameter of about 0.034″ and a wall thickness of about 0.001″ with the outer diameter etched, and a length of about 5.0 cm, while there are preferably two counterwound ribbon coils 222 of a superelastic or shape memory alloy, such as nickel titanium (optionally with chromium) of about 0.007″ by about 0.010″ with a pitch of about 0.015″ and a length of about 4.0 cm. Inner tube 218 might alternatively comprise ETFE, gamma stable PTFE, FEP, or the like, while ribbon coils 222 may comprise a stainless steel or other medical grade materials. An inner diameter of the distal portion may be about 0.034″, with the distal outer diameter of sheath 214 being about 0.041″. An intermediate outer tube 224 may comprise a polyurethane having a durometer of about 55. A length of outer tube 220 may be about 1.0 cm, a length of intermediate tube 224 may be about 5 mm, and a length of proximal portion 216 may be about 40 cm. As can be understood with reference to FIG. 20, and as explained in detail in co-pending application Ser. No. ______ (Attorney Docket No. 16355-003910US), a proximal handle mechanism 230 may be provided to help coordinate motion of the outer sheath, delivery catheter, corewire, and/or the like. This proximal handle may have a handle body which is axially coupled to the contraceptive device, and any of a wide variety of actuation mechanisms (such as syringe-like sliders, ratcheting trigger handles, rack-and-pinion thumb wheels, and the like) can be used to move, for example, a proximal end of the outer sheath 14 and/or a proximal end of release catheter 16 relative to a proximal end of core wire 18. Advantageously, these proximal handle mechanisms can be arranged to, for example, expose the proximal portion of contraceptive device 12, then deploy the retention structure, and then detach the deployed device from the delivery system (as explained above), with two or more of these steps integrated into a continuous actuation movement at handle 230. Such actuation handles may greatly reduce the workload on the attending medical staff, possibly reducing the number of persons needed to effect deployment, and/or allowing contraceptive device exposure, deployment, and/or detachment to be effected with one hand on handle 230 (allowing the other hand to position a hysteroscope or the like). Still further modifications of the contraceptive device and/or delivery system are possible. For example, polyester fibers may be disposed both within primary coil 50 (ideally in the form of fiber loops) and around coil 50 (ideally in the form of wound Dacron® layers disposed between primary coil 50 and outer coil 56) so as to more fully occlude the tubal lumen. While the exemplary embodiment of the present invention has been described in some detail, for clarity of understanding and by way of example, a variety of adaptations, changes, and modifications will be obvious to those who are skilled in the art. Hence, the scope of the present invention is limited solely by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention generally relates to contraception and/or sterilization, and more particularly to temporary or permanent intrafallopian contraceptive devices, delivery systems, and non-surgical methods for their deployment. While the theoretical effectiveness of existing non-surgical contraceptive techniques, including barrier methods and hormonal therapies, is well established, the actual effectiveness of most known methods is disappointing. One reason for these disappointing results is that many of the presently available methods for inhibiting pregnancy without surgery depend upon significant user involvement. Non-compliance typically results in quite high rates of failure, and overcoming user non-compliance to improve overall efficacy has proven quite difficult. One form of long term contraception which is less susceptible to user non-compliance is the intrauterine device (IUD). IUDs have been found to have higher rates of reliability, and are effective for a longer period of time, then most other commercially available contraceptives. Unfortunately, IUDs are also associated with serious infectious complications. For this reason, the use of IUDs within the United States has decreased dramatically. Additionally, IUDs are subject to unplanned expulsion, and are removed due to excessive pain or bleeding in a significant percentage of cases, further reducing acceptance of the IUD as a method of inhibiting pregnancy. Commercially available options for permanent sterilization include fallopian tube ligation and vasectomy. These methods are surgical and are not available to many people in the world. It is common knowledge that fertilization occurs in the fallopian tubes where the sperm and ovum meet. Tubal ligation avoids this by surgical and complete occlusion of the fallopian tubes. In work done in connection with the present invention, it has previously been proposed to transcervically introduce a resilient coil into a fallopian tube so as to inhibit conception. PCT Patent Application No. 99/15116, assigned to the present assignee (the full disclosure of which is incorporated herein by reference) describes devices which are transcervically inserted into a tubal ostium and mechanically anchored within the fallopian tube. The described devices may promote a tissue ingrowth network to provide long term conception and/or permanent sterilization without the need for surgical procedures, and should avoid the risks of increased bleeding, pain, and infection associated with intrauterine devices. While the recently proposed intrafallopian contraceptive devices represent a significant advancement in the art, still further improvements would be desirable. In general, it would be desirable to provide improved non-surgical devices, systems, and methods for inhibiting pregnancy. It would be beneficial if these improved techniques increased the ease with which these contraceptive devices could be deployed, and if the improvements further enhanced the long term retention of the contraceptive device once it has been deployed. It would be further beneficial if these improved access and deployment techniques were suitable for a wide variety of physiological geometries, ideally without having to tailor the device, deployment system, or deployment method for specific individuals. Some or all of these advantages are provided by the devices and methods described hereinbelow. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention generally provides improved contraceptive and/or sterilization methods, systems, and devices. The invention generally improves the ease, speed, and reliability with which a contraceptive device can be deployed transcervically into an ostium of a fallopian tube. In many embodiments, a distal portion of the contraceptive device will function as a guidewire, facilitating advancement of the device (and the deployment system) into the tubal ostium. Typically, a proximal portion of the device will remain covered by a deployment sheath until the device is in position. Thereafter, the sheath can be withdrawn proximally, exposing a surface which is well adapted for retaining the device within the tube and/or uterotubal junction (but which would not be ideal for facilitating advancement of the device if left unsheathed during positioning). In the exemplary embodiment, the proximal portion remains in a small profile configuration while the sheath is withdrawn proximally, and is thereafter expanded to a large profile configuration engaging the surrounding tissues. Actuation may be affected after withdrawal of the sheath by a variety of mechanisms, ideally by restraining a helical coil of the proximal portion using first and second elongate bodies. Releasing one of the bodies relative to the other can release the exposed helical coil to expand resiliently. The released helical coil can safely engage and anchor the contraceptive device within a wide variety of physiological tissue geometries. Using the distal end of the contraceptive device as a guidewire avoids the complexity of multiple step deployments (which might otherwise involve separate guidewire access, catheter access, and advancement of the device), while still providing a smooth, easily advanced outer system profile. In a first aspect, the invention provides a contraceptive method comprising guiding a contraceptive device distally into an ostium of a fallopian tube with an exposed distal portion of the contraceptive device while a sheath covers a proximal portion of the contraceptive device. The proximal portion of the guided contraceptive device is uncovered by withdrawing a sheath proximally from the proximal portion. The uncovered contraceptive device is released so that the contraceptive device inhibits conception. Typically, the contraceptive device comprises an axially elongate flexible structure. Advantageously, the proximal portion of this flexible structure can be supported by the surrounding sheath while the distal portion is acting as a guidewire. Often times, at least a portion of the exposed distal portion can be supported with a core support (for example, a removable core wire) disposed within an axially oriented lumen of the contraceptive device. Preferably, the distal portion will flex laterally to track through the uterotubal junction so that the contraceptive device is positioned across the muscular lumen narrowing adjacent of the uterotubal junction. A distal ball tip having a diameter in a range from about 0.020 inches to 0.050 inches can help avoid perforation and facilitate tubal navigation. In another aspect, the invention provides a contraceptive method comprising inserting a contraceptive device distally into an ostium of a fallopian tube. A proximal portion of the inserted contraceptive device is uncovered by withdrawing a sheath from around the proximal portion. An expandable structure of the proximal portion is maintained in a small profile configuration during the uncovering step so as to avoid restricting movement of the sheath while the sheath is withdrawn. The uncovered expandable structure is radially expanded to a large profile configuration so as to affix the contraceptive device within the ostium. The uncovered contraceptive device is released so that the contraceptive device inhibits conception. Preferably, the expandable portion is maintained in the small profile configuration using a restraining force or torque. This restraint can be transmitted proximally using a first elongate body and a second elongate body. Typically, the first and second elongate bodies sustain a wind-down torque on the expandable structure. The expandable structure can be expanded by actuating the proximal handle so as to rotationally and/or axially release a proximal end of the elongate bodies relative to each other. In another aspect, the invention provides a contraceptive system comprising an intrafallopian contraceptive device having a proximal portion adjacent a proximal end and a distal portion adjacent a distal end. The distal portion has a flexibility suitable to function as a guidewire. A sheath is releasably secured over the proximal portion of the contraceptive device so that the distal portion of the contraceptive device remains exposed when the contraceptive device and sheath are inserted transcervically into an ostium of the fallopian tube. A first elongate body extends from a proximal end distally into detachable engagement with the contraceptive device for withdrawing the sheath from around the inserted contraceptive device. In yet another aspect, the invention provides a contraceptive kit comprising a contraceptive device and instructions for deploying the contraceptive device. The instructions describe the method steps of guiding the contraceptive device into an ostium of a fallopian tube with a distal portion of the contraceptive device. The instructions also describe uncovering a proximal portion of the contraceptive device so that the proximal portion can restrain the contraceptive device within the ostium. | 20040715 | 20070703 | 20050303 | 76617.0 | 1 | BROWN, MICHAEL A | INSERTION/DEPLOYMENT CATHETER SYSTEM FOR INTRAFALLOPIAN CONTRACEPTION | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,892,791 | ACCEPTED | Packet switching node | To provide fast access times with very large key fields, an associative memory utilizes a location addressable memory and lookup table to generate from a key the address in memory storing an associated record. The lookup tables, stored in memory, are constructed with the aid of arithmetic data compression methods to create a near perfect hashing of the keys. For encoding into the lookup table, keys are divided into a string of symbols. Each valid and invalid symbol is assigned an index value, such that the sum of valid index values for symbols of a particular key is a unique value that is used as an address to the memory storing the record associated with that key, and the sum of keys containing invalid index values point to a location in memory containing similar data. Utilizing the lookup tables set and relational operations maybe carried out that provide a user with a maximum number of key records resulting from a sequence of intersection, union and mask operations. | 1. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address; circuitry for, determining if a MAC source address of a received packet has been stored and associated with one of the at least three communications ports; if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which the received packet is received, storing an association of the MAC source address with the one of the at least three communications ports at which the packet was received and causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and if the MAC source address of the received packet is associated by the node with the one of the at least three communications ports at which it is received, causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received. 2. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; circuitry for, determining if a MAC source address of a received packet has been stored by the node and associated with one of the at least three communications ports at which the packet was received; if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which it was most recently received, (i) storing an association of the MAC source address with the one of the at least three communications ports at which the packet was most recently received, (ii) causing the received packet to be forwarded on one of the at least three communications ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received, and (iii) storing in the node an indication that the MAC source address has been recently used; if the MAC source address is associated with the one of the at least three communications ports at which it arrived, storing an indication that the MAC source address has been recently used, and causing the received packet to be forwarded on one of the at least three communications ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and disassociating MAC addresses from any of the at least three communications ports that have not been the MAC source address in any packet at the node within a preceding period of time. 3. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; circuitry for, determining if a MAC source address of a received packet has been stored by the node and associated with one of the at least three communications ports at which the packet was received; accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the packet according to the source filtering information; if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which it was most recently received, storing an association of the MAC source address with the one of the at least three communications ports at which the packet was received, and causing the received packet to be forwarded on one of the at least three communications ports with which the received packet's MAC destination address is associated, or, if the received packet's MAC destination address is not associated with any of the at least three communications ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and if the MAC source address is associated with the one of the at least three communications ports at which it arrived, causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received. 4. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; circuitry for, storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address. 5. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; circuitry for, storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; if the destination MAC address associated by the node with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and if the destination MAC address associated by the node with the IP destination address does not have an association with one of the at least three-communications ports stored by the node, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets except for the one of the at least three communications ports on which the packet was received. 6. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; circuitry for, storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and. if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node. 7. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; circuitry for, storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node; and broadcasting an IP address resolution protocol packet on each of the at least three communications ports, the IP address resolution protocol packet containing the MAC address and IP address of the packet switching node, and receiving in response the MAC address and IP address of each device that is coupled at a MAC level with one of the at least three communications ports and that has been assigned an IP address. 8. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; circuitry for, storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and if the destination MAC address associated with the IP destination address of the received packet does not have a stored association with one of the at least three communications ports, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets except for the one of the at least three communications ports on which the packet was received; transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node; broadcasting an IP address resolution protocol packet on each of the at least three communications ports, the IP address resolution protocol packet containing the MAC address and IP address of the packet switching node, and receiving in response the MAC address and IP address of each device that is coupled at a MAC level with one of the at least three communications ports and that has been assigned an IP address. 9. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; circuitry for, storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the received packet according to the source filtering information; if the received packet is to be forwarded, encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address. 10. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; circuitry for, storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the received packet according to the source filtering information; if the received packet is to be forwarded, encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and if the node has no stored association between the destination MAC address associated with the IP destination address of the received packet and at one of the least three communications ports, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets according to the source filtering information associated with the source IP address, but not out the one of the at least three communications ports on which the packet was received. 11. A packet switching node comprising: a least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; circuitry for, if a first MAC address contained in a MAC source address field of a packet received on one of the at least three communications ports has a stored association with one of the three least communications ports at which it was received, and if source address filtering information is associated with the first MAC address contained in the received packet, filtering the received packet according to the source filtering information; if the node has no stored association between the first MAC address and one of the at least three communications ports at which it is received, associating the first MAC address with the one of the at least three communications ports at which the packet was received and, if source address filtering information is associated with the first MAC address, filtering the received packet according to the source filtering information; if a second MAC address contained in a MAC destination address field of the received packet has stored association with one of the least three communications ports, causing the packet to be forwarded out the one of the at least three communications with which the second MAC is associated if allowed by the source filtering information associated with the first MAC address; and if the second MAC address contained in the received packet does not have a stored association with any one of the least three communications ports, forwarding the received packet from each one of the at least three communications ports except the one of the at least the communications ports at which the packet was received if allowed b the source filtering information associated with the first MAC address. 12. A packet switching node comprising: a least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; circuitry for, determining if a first MAC address contained in a MAC source address field of a packet received on one of the at least three communications ports does not have a stored association with one of the three least communications ports at which it was received, and associating the first MAC address with the one of the at least three communications ports at which the packet was received; if a second MAC address contained in a MAC destination address field of the received packet has a stored association with one of the least three communications ports, causing the received packet to be forwarded on the one of the at least three communications ports with which the second MAC address is associated unless the one of the at least three communications ports, with which the second MAC address is associated, is associated with a stored protection record indicating protection of that communications port from packets containing the first MAC address as a MAC source address; and if the second MAC address contained in the received packet does not have a stored association with any one of the least three communications ports, forwarding the received packet on each one of the at least three communications ports, except the one of the at least the communications ports at which the packet was received, that are allowed by the stored protection record to forward packets having been received with the first MAC as a MAC source address. 13. A method for switching packets at a node at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: determining if a MAC source address of a received packet has been stored and associated with one of the at least three communications ports; if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which the received packet is received, storing an association of the MAC source address with the one of the at least three communications ports at which the packet was received and causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and if the MAC source address of the received packet is associated by the node with the one of the at least three communications ports at which it is received, causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received. 14. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: determining if a MAC source address of a received packet has been stored by the node and associated with one of the at least three communications ports at which the packet was received; if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which it was most recently received, (i) storing an association of the MAC source address with the one of the at least three communications ports at which the packet was most recently received, (ii) causing the received packet to be forwarded on one of the at least three communications ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received, and (iii) storing in the node an indication that the MAC source address has been recently used; if the MAC source address is associated with the one of the at least three communications ports at which it arrived, storing an indication that the MAC source address has been recently used, and causing the received packet to be forwarded on one of the at least three communications ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and disassociating MAC addresses from any of the at least three communications ports that have not been the MAC source address in any packet at the node within a preceding period of time. 15. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: circuitry for, determining if a MAC source address of a received packet has been stored by the node and associated with one of the at least three communications ports at which the packet was received; accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the packet according to the source filtering information; if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which it was most recently received, storing an association of the MAC source address with the one of the at least three communications ports at which the packet was received, and causing the received packet to be forwarded on one of the at least three communications ports with which the received packet's MAC destination address is associated, or, if the received packet's MAC destination address is not associated with any of the at least three communications ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and if the MAC source address is associated with the one of the at least three communications ports at which it arrived, causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received. 16. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address. 17. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; if the destination MAC address associated by the node with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and if the destination MAC address associated by the node with the IP destination address does not have an association with one of the at least three-communications ports stored by the node, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets except for the one of the at least three communications ports on which the packet was received. 18. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node. 19. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node; and broadcasting an IP address resolution protocol packet on each of the at least three communications ports, the IP address resolution protocol packet containing the MAC address and IP address of the packet switching node, and receiving in response the MAC address and IP address of each device that is coupled at a MAC level with one of the at least three communications ports and that has been assigned an IP address. 20. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and if the destination MAC address associated with the IP destination address of the received packet does not have a stored association with one of the at least three communications ports, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets except for the one of the at least three communications ports on which the packet was received; transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node; broadcasting an IP address resolution protocol packet on each of the at least three communications ports, the IP address resolution protocol packet containing the MAC address and IP address of the packet switching node, and receiving in response the MAC address and IP address of each device that is coupled at a MAC level with one of the at least three communications ports and that has been assigned an IP address. 21. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the received packet according to the source filtering information; if the received packet is to be forwarded, encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address. 22. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; removing the source and destination MAC addresses of a received packet; accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the received packet according to the source filtering information; if the received packet is to be forwarded, encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and if the node has no stored association between the destination MAC address associated with the IP destination address of the received packet and at one of the least three communications ports, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets according to the source filtering information associated with the source IP address, but not out the one of the at least three communications ports on which the packet was received. 23. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: if a first MAC address contained in a MAC source address field of a packet received on one of the at least three communications ports has a stored association with one of the three least communications ports at which it was received, and if source address filtering information is associated with the first MAC address contained in the received packet, filtering the received packet according to the source filtering information; if the node has no stored association between the first MAC address and one of the at least three communications ports at which it is received, associating the first MAC address with the one of the at least three communications ports at which the packet was received and, if source address filtering information is associated with the first MAC address, filtering the received packet according to the source filtering information; if a second MAC address contained in a MAC destination address field of the received packet has stored association with one of the least three communications ports, causing the packet to be forwarded out the one of the at least three communications with which the second MAC is associated if allowed by the source filtering information associated with the first MAC address; and if the second MAC address contained in the received packet does not have a stored association with any one of the least three communications ports, forwarding the received packet from each one of the at least three communications ports except the one of the at least the communications ports at which the packet was received if allowed b the source filtering information associated with the first MAC address. 24. A method for switching packets at a node having at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address, comprising: determining if a first MAC address contained in a MAC source address field of a packet received on one of the at least three communications ports does not have a stored association with one of the three least communications ports at which it was received, and associating the first MAC address with the one of the at least three communications ports at which the packet was received; if a second MAC address contained in a MAC destination address field of the received packet has a stored association with one of the least three communications ports, causing the received packet to be forwarded on the one of the at least three communications ports with which the second MAC address is associated unless the one of the at least three communications ports, with which the second MAC address is associated, is associated with a stored protection record indicating protection of that communications port from packets containing the first MAC address as a MAC source address; and if the second MAC address contained in the received packet does not have a stored association with any one of the least three communications ports, forwarding the received packet on each one of the at least three communications ports, except the one of the at least the communications ports at which the packet was received, that are allowed by the stored protection record to forward packets having been received with the first MAC as a MAC source address. 25. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each communications port having an associated with it a MAC address; means for determining if a MAC source address of a received packet has been stored and associated with one of the at least three communications ports; if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which the received packet is received, means for storing an association of the MAC source address with the one of the at least three communications ports at which the packet was received and causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and if the MAC source address of the received packet is associated by the node with the one of the at least three communications ports at which it is received, means for causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, means causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received. 26. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; means for determining if a MAC source address of a received packet has been stored by the node and associated with one of the at least three communications ports at which the packet was received; means for, if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which it was most recently received, (i) storing an association of the MAC source address with the one of the at least three communications ports at which the packet was most recently received, (ii) causing the received packet to be forwarded on one of the at least three communications ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received, and (iii) storing in the node an indication that the MAC source address has been recently used; means for, if the MAC source address is associated with the one of the at least three communications ports at which it arrived, storing an indication that the MAC source address has been recently used, and causing the received packet to be forwarded on one of the at least three communications ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and means for disassociating MAC addresses from any of the at least three communications ports that have not been the MAC source address in any packet at the node within a preceding period of time. 27. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; means for determining if a MAC source address of a received packet has been stored by the node and associated with one of the at least three communications ports at which the packet was received; means for accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the packet according to the source filtering information; means for, if the MAC source address of the received packet is not stored by the node, or if the MAC source address of the received packet is not associated with the one of the at least three communications ports at which it was most recently received, storing an association of the MAC source address with the one of the at least three communications ports at which the packet was received, and causing the received packet to be forwarded on one of the at least three communications ports with which the received packet's MAC destination address is associated, or, if the received packet's MAC destination address is not associated with any of the at least three communications ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received; and means for, if the MAC source address is associated with the one of the at least three communications ports at which it arrived, causing the received packet to be forwarded on one of the at least three ports with which the packet's MAC destination address is associated or, if the MAC destination address is not associated with any of the at least three ports, causing the received packet to be forwarded on all of the at least three communications ports except the one of the at least three communications ports at which the packet was received. 28. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; means for storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; means for removing the source and destination MAC addresses of a received packet; means for encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and means for, if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address. 29. The packet switching node of claim 28, further comprising means for, if the destination MAC address associated by the node with the IP destination address does not have an association with one of the at least three-communications ports stored by the node, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets except for the one of the at least three communications ports on which the packet was received. 30. The packet switching node of claim 28, further comprising means for transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node. 31. The packet switching node of claim 30, further comprising means for broadcasting an IP address resolution protocol packet on each of the at least three communications ports, the IP address resolution protocol packet containing the MAC address and IP address of the packet switching node, and receiving in response the MAC address and IP address of each device that is coupled at a MAC level with one of the at least three communications ports and that has been assigned an IP address. 32. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; means for storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received, if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet, means for removing the source and destination MAC addresses of a received packet; means for encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; means for, if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address; and means for, if the destination MAC address associated with the IP destination address of the received packet does not have a stored association with one of the at least three communications ports, sending the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets except for the one of the at least three communications ports on which the packet was received; and means for transmitting IP routing protocol packets to other packet switching nodes, and receiving IP routing protocol packets from other packet switching nodes, on one or more of the at least three communications ports in order to identify IP addresses that may be reached from each of the at least three communications ports of the packet switching node; means for broadcasting an IP address resolution protocol packet on each of the at least three communications ports, the IP address resolution protocol packet containing the MAC address and IP address of the packet switching node, and receiving in response the MAC address and IP address of each device that is coupled at a MAC level with one of the at least three communications ports and that has been assigned an IP address. 33. A packet switching node comprising: at least three IEEE 802 media access controller (MAC) communications ports, each of the at least three communications ports having a MAC address; means for storing an association between a MAC source address of a received packet and one of the at least three communications ports at which the packet was received by the node if there is no association between the MAC source address and the one of the at least three communications ports at which the packet is received; and if the received packet contains a destination MAC address that is a MAC address associated with the node, and if the packet encapsulates an Internet Protocol (IP) packet; means for removing the source and destination MAC addresses of a received packet; means for accessing stored source filtering information associated with a source Internet Protocol (IP) address contained in the received packet and filtering the received packet according to the source filtering information; means for, if the received packet is to be forwarded, encapsulating the IP packet as a MAC packet with a destination MAC address associated by the node with an IP destination address contained in the IP packet; and means for, if the destination MAC address associated with the IP destination address has an association stored by the node with one of the at least three communications ports, sending the encapsulated IP packet out the one of the at least three communications ports associated with the destination MAC address. 34. The packet switching node of claim 33, further comprising means for sending, if the node has no stored association between the destination MAC address associated with the IP destination address of the received packet and at one of the least three communications ports, the encapsulated IP packet out all of the at least three communications ports that are allowed to forward MAC packets according to the source filtering information associated with the source IP address, but not out the one of the at least three communications ports on which the packet was received. 35. A packet switching node comprising: a least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; means for, if a first MAC address contained in a MAC source address field of a packet received on one of the at least three communications ports has a stored association with one of the three least communications ports at which it was received, and if source address filtering information is associated with the first MAC address contained in the received packet, filtering the received packet according to the source filtering information; means for, if the node has no stored association between the first MAC address and one of the at least three communications ports at which it is received, associating the first MAC address with the one of the at least three communications ports at which the packet was received and, if source address filtering information is associated with the first MAC address, filtering the received packet according to the source filtering information; means for, if a second MAC address contained in a MAC destination address field of the received packet has stored association with one of the least three communications ports, causing the packet to be forwarded out the one of the at least three communications with which the second MAC is associated if allowed by the source filtering information associated with the first MAC address; and means for, if the second MAC address contained in the received packet does not have a stored association with any one of the least three communications ports, forwarding the received packet from each one of the at least three communications ports except the one of the at least the communications ports at which the packet was received if allowed b the source filtering information associated with the first MAC address. 36. A packet switching node comprising: a least three IEEE 802 media access controller (MAC) communications ports, each communications port having associated with it a MAC address; means for determining if a first MAC address contained in a MAC source address field of a packet received on one of the at least three communications ports does not have a stored association with one of the three least communications ports at which it was received, and associating the first MAC address with the one of the at least three communications ports at which the packet was received; means for, if a second MAC address contained in a MAC destination address field of the received packet has a stored association with one of the least three communications ports, causing the received packet to be forwarded on the one of the at least three communications ports with which the second MAC address is associated unless the one of the at least three communications ports, with which the second MAC address is associated, is associated with a stored protection record indicating protection of that communications port from packets containing the first MAC address as a MAC source address; and means for, if the second MAC address contained in the received packet does not have a stored association with any one of the least three communications ports, forwarding the received packet on each one of the at least three communications ports, except the one of the at least the communications ports at which the packet was received, that are allowed by the stored protection record to forward packets having been received with the first MAC as a MAC source address. | RELATED APPLICATIONS This application is a continuation application of U.S. application Ser. No. 09/227,688, filed on Jan. 8, 1999, which is a continuation of U.S. application Ser. No. 08/174,361, filed Dec. 28, 1993, which is a continuation-in-part of U.S. application Ser. No. 07/952,988, filed on Sep. 29, 1992, now U.S. Pat. No. 5,490,258, which is a continuation-in-part of U.S. application Ser. No. 07/737,147, filed on Jul. 29, 1991, now abandoned, which is a continuation-in-part of U.S. application Ser. No. 07/367,012, now U.S. Pat. No. 5,095,480. THE FIELD OF THE INVENTION The present invention relates to associative memory systems, and more particularly to associative memory systems for handling large key set and spaced. BACKGROUND OF THE INVENTION Data communication between computers has become a standard part of worldwide networks in many areas of endeavors. These individual networks gather data about diverse subjects and exchange information of common interest among various media groups. Most of these networks are independent communication entities that are established to serve the needs of a particular group. Some use high speed connections while others use slow speed networks. Some use one type of protocol while others use a different type of protocol. Other well-known differences between networks also exist. There has been considerable effort expended in an attempt to make it possible to interconnect disparate physical networks and make them function as a coordinated unit. Whether they provide connections between one computer and another or between terminals and computers, communication networks are divided basically into circuit-switched or packet-switched types. Circuit-switched networks operate by forming a dedicated connection between two points. Such a dedicated circuit could be represented by a telephone connected through a circuit from the originating phone to a local switching, office, across trunk lines to a remote switching office and finally to the destination telephone. When that circuit is complete, no other communications can travel over the wires that form the circuit. The advantage of such circuit lies in the fact that once it is established, no other network activity will decrease the capacity of the circuit. The disadvantage is that concurrent communication cannot take place on the line or circuit. Packet-switched networks take an entirely different approach. In such system, traffic on the network is divided into small segments of information called packets that are multiplexed on high capacity intermachine connections. Each packet carries identification that enables other units on the network to know whether they are to receive the data or are to transmit it to another destination. The chief advantage of packet-switching is that multiple communications among information sources such as computers can proceed concurrently with connections between machines being shared by all machines that are communicating. The disadvantage is that as activity increases, a given pair of communicating devices can use less of the network capacity. A new technology has been developed that is called Internet and it accommodates information or communication networks having multiple, diverse underlying hardware technologies, or physical media protocols, by adding both physical connections and a new set of conventions. One of the problems with the use of Internet is that addresses refer to connections and not to the device itself that is sending the information. Thus, if a communication source, such as an aircraft for example, moves from one communication network to another, its Internet address must change. Specifically, if an aircraft is transmitting a particular location address code in one communication network in the Internet system and it moves to another, its Internet address must change. It is similar to a traveler who has a personal computer operating with a first communication network. If the computer is taken on a trip and connected into the information system after reaching the new destination, a new location address for the computer must be obtained for the new destination. It is also similar to moving a telephone from one location to another. A new telephone number must be assigned to the telephone at the new location. The telephone cannot be reached at the new location with the old number. Further, when routing a signal from one station to another through a plurality of nodes forming multipath connections, the message format contains a destination location address that is used to make the routing decisions. When the system has multiple addresses, the route taken by the packets traveling to a particular station address depends upon the location code embedded in the station address. Thus, two problems occur in such message communication networks. The first is the requirement to change the address code of the communication source when it is at different locations in the network and the second is routing the message to the receiver if the address has changed. It can be seen, then, that with the presently existing system, if host A transmits a message to host B with a specific location code, by the time the message arrives at that location, host B may have moved to a new information processing network and changed its location code to conform to the new system and thus could not receive the message transmitted by host A. Host A must know that host B has entered the new information processing system and then must change the format of the new location address in order to contact host B. The present system overcomes the disadvantages of the prior art by simply assigning a fixed, unique and unchanging identification code to both host A and host B. As host B enters into a new network access system, it transmits its identification code to the nearest node and all of the nodes interconnecting all of the disparate networks each store, with the unique identification code of host B, the address of those nodes which can communicate with host B so that a path can be completed through the nodes between host A and host B. In the prior art, hierarchical logical routing is used to address highly mobile end-systems (computers on ships and aircraft, etc.) that are simultaneously connected to multiple communication paths and employ multicast message traffic. Hierarchical routing schemes have great difficulty solving this combined set of problems and a new approach must be used to overcome the difficulties in using hierarchical routing to meet the user's diverse requirements. Further, in the prior art, a logical network address of larger than 32 bits was too large to be used as a directory access method to locate a receiver at a location address specified in the message format. Specialized hierarchical address structures which embed network location information have been employed to reduce the size of the access index to the routing table and also to reduce the size of the routing table. This approach couples the address structure to the Internet routing software design. There are various “hidden assumptions” of hierarchical addressing. These “hidden assumptions” are (1) the processing load of the router CPU increases as the size of the routing table increases and (2) computer memory is a scarce and expensive resource. The present invention overcomes the first of these problems while computer memory technology has addressed the second problem by making very large memories cost effective. Traditional approaches for designing a network address structure have either been intimately entwined in the design of efficient routing look-up tables or assigned by a central authority such as ARPANET. Neither of these approaches gives much if any thought to the needs, desires or ease of use of the group which must make operational use of the system. In an age of fourth generation database languages and high level compilers, network addresses are basically hand-coded in low level language. Addresses and address structures are difficult to change as a mobile end-unit moves from one communication network to another. Experts are often required to ensure that operational equipment is properly integrated into the system. ISO (International Standards Organization) addressing provides a basis for a much better approach but the overall design and administration of a network addressing structure must be elevated to an easily supported, user friendly, distributed architecture to effectively support the user's long-term needs. Traditional directory access methods, whether for Internet routing, databases or compiler symbol tables, fall into three basic categories: (1) Sorted Tables. The keys are sorted by some rule which allows a particular search strategy (e.g., binary search) to locate the key. Associated with the key location is a pointer to the data. (2) Tree Structures. Parts of the key field are used to traverse a tree data structure to a leaf node which holds the data or a pointer to the data. (3) Hashing. Some arithmetic function is applied to the key which compresses the key field into a chosen integer range which is the initial directory size. This integer is the index into the directory which usually contains a pointer to the data. Each of these techniques has advantages and disadvantages when applied to the Internet routing table access design. Sorted tables provide the potentially most compact storage utilization at the cost of having access computations which grow with the number of addresses (keys) active in the system. Computations for sorted tables grow proportional to the log of the number of keys plus one. Using sorted tables, the router processing will slow down as the number of active addresses increases. But the desirable result is to make computation independent of the number of active addresses. It has been theorized, without providing a method, that a scheme to access sorted tables could exist which always allows access in two probes. To date, no methods have been proposed which approaches this theoretical result. Tree data structures have been widely employed for directories, particularly for file systems, such as the UNIX file system where larger amounts of auxiliary disc storage is being managed. Trees offer access times that are proportional to the length of the address (key). Trees trade off memory space for processing load. More branches at each level decreases the processing but uses much more memory. For example, a binary tree uses two locations at each level for each bit in the address field for which there is an active address. The binary tree processing of an eight bit octet requires eight memory accesses as well as unpacking the bits from the octet. On the other hand, processing a 256 way tree takes one memory access using the address octet as an index at each level. A 256 way tree requires 256 locations at the next level for every different octet active (a valid value) at the current level. An address of six octets with ten valid octet values in each octet position would require 256×106 (256 million) locations, rapidly reaching an unrealizable size on current computer equipment. With current realizable computer memory sizes, pure tree structures do not appear to offer a viable structure for real time, address independent directory access method. Hashing has often been used over the last several decades to create directories where fast access is desired. One system uses a multi-level hashing scheme as the file system directory structure. The Total database system is based on hashed key access. Many language compilers use hash tables to store symbols. Hash table schemes have good average access costs—often a single access, but can degrade drastically when the table becomes too full or the hashing function does not perform a good job of evenly distributing the keys across the table. Some techniques called “linear hashing” and “dynamic hashing” have provided the method of expanding the hash table when a particular bucket becomes too full instead of using the traditional linked list overflow methods. These techniques generally require about 40% more space than the number of active addresses (keys) to achieve single access speed without employing overflow methods. All general hashing techniques use a variation of several common randomizing functions (such as dividing the key by a prime number and using the remainder) to “compress” the key field into a much smaller integer index into the hash table. Hashing functions have traditionally been viewed as one-way, randomized mapping of the key set into the hash space. The index computed by the hashing function could not be used to reconstruct the key. If for a particular hash function there exists a reciprocal function which maps the index to the unique key which generated the index, then the compressed keys could be stored in the directory. The present invention overcomes the disadvantages of the prior art by considering a flat, as opposed to hierarchical, logical routing address space with unique identifiers assigned to each transmitter and receiver to vastly simplify the modern communication problems of addressing highly mobile end-systems which are simultaneously connected to multiple communication paths and employ multicast message traffic. Further, the present invention employs a reversible arithmetic code compression technique to reduce the logical network address of up to 128 bits to a unique integer value which preserves any hierarchical ordering of the network address. Also, the present invention employs dynamic hashing and memory allocation techniques to automatically adjust the size of the routing table directory and routing records to accommodate the number of end-system addresses currently active in the communication system. These techniques provide a selection of approaches to allow graceful degradation of the routing efficiency when the memory available for routing tables is full. Finally, the system improves over the prior art by using a message format that is structure independent of the location of the destination of the message receiver. Arithmetic coding, when applied to addresses as known length keys, provides several advantages for table look-up when the addresses are known or can be learned in advance as they are in communications applications. The proposed arithmetic coding routing table design provides direct support for mobile, multi-homed, shared network end-systems employing multicast and unicast messaging while minimizing the effects of the “hidden assumptions” that have lead to reducing the routing table size by embracing hierarchical routing schemes. First, the identification encoding parameter tables are easily constructed by counting the occurrence of a particular symbol value and the accumulative distribution over all octet occurrences. That is, the tables are scaled to the statistical occurrence of each octet value. When a “bucket” overflows, dynamic hashing approaches can be used to expand the directory or parameter tables. Secondly, arithmetic coding can be constructed to operate on each symbol position in the address field as it arrives, allowing processing to begin as soon as the first address symbol arrives. Thirdly, arithmetic coding preserves the hierarchical (left to right precedence) of the ISO addresses being encoded. This is desirable if an Internet router only has knowledge of the network address but the Internet header carries the full destination address of a succeeding system node. Finally, a constant known set of computations is required for each symbol of the address field independent of the number of address symbols or the number of active Internet addresses. These features make the arithmetic coding used herein an ideal candidate for the routing table directory structure that is independent of a location address in a router, gate way or end-system. The present invention provides a very fast, automatically expandable, source filtered Internet routing scheme totally independent of the internal logical or physical structure of the network addresses in the message format that it is routing. Addresses are just unique identification numbers represented by a string of symbols of known length. Each Internet router learns the location of these numbers within the network from the Internet protocol traffic, from the source addresses of the packets it receives, and from a network management protocol. Address independent routing tables provides the following direct benefits: They provide a very fast routing table access scheme that is capable of supporting fast packet switch designs for very high speed media such as FDDI (i.e., routers which begin the outbound transmission of the packet as soon as possible after receiving the Internet header and before the whole packet has been received). They allow source address filtering for efficient multicast operation and security partitioning of the network. They allow independent automatic generation of network addresses from a user name space by a network name service. This facilitates using the same Internet software in disconnected networks with different addressing authorities and different address structures. They allow for orderly expansion, restructuring and redesign of the user name space without changing the Internet code or table structure. They reduce initial system procurement and logistic support costs because no special coding is needed for different networks. They reduce life cycle system costs because the Internet routers automatically adapt to network changes and they can be expanded without routing table modification. The present invention combines arithmetic coding with dynamic hashing to provide a very high speed method and system for detecting the 48 bit physical addresses in a Media Access Controller (MAC). The present system guarantees the acceptance or rejection of a frame. This technique always performs address detection functions within the transmission time of the address field plus a small fixed number of octet clocks depending on the logic implementation chosen. Specifically, the present system provides the following features: (1) variable length addresses with no known internal structure and processed with a number of memory accesses and a processing time proportional to the number of octets in the address field; (2) the size of the routing tables is directly proportional to the number of active addresses known to the router and within the practical limits of currently available microprocessing systems; (3) and the computational operations required to access the routing table for any address is linearly proportional to the length of the address field and these computations are reasonably performed by currently available microprocessor systems. SUMMARY OF THE INVENTION Thus the present invention relates to a system for routing a message between a source and a destination and which utilizes a message format that is structure-independent of the location of the message destination, said system comprising at least a first signal transceiver device having only a first fixed unique identification code wherever the transceiver device may be located; at least a second signal transceiver device for communicating with the first transceiver device and having only a second fixed unique identification code wherever the second transceiver device may be located; and routing nodes for coupling a transmitted signal from the first transceiver device to the second transceiver device at an unknown physical location within the system using a routing message format containing only the first and second transceiver fixed unique identification codes and addresses of the routing nodes with a message format that is structure-independent of any transceiver location code. Another aspect of the invention is an apparatus and method for implementing a routing table directory to provide for fast access times to look up routing information. This apparatus is an application of a novel associative memory utilizing arithmetic coding to associate a key presented to the memory with a record stored in the memory, but has a very-wide range of application in many different types of data processing systems. The associative memory includes an index table stored in memory and a record memory for storing the records of data. The index table is constructed such that each symbol of a key, a key being divided into a string of symbols and each symbol being defined by its position within the key and its value, addresses an index value in the index table memory. These index values are assigned such that the sum of index values for a given key is a unique value that is used to address the record memory. Several methods and apparatus are disclosed the permit random assignment of index values to new keys as they are presented, as well as for keys that are presented in sorted order for addition to the memory. Another aspect of the invention provides a method and apparatus for utilizing use-count tables created by the arithmetic coding process to determine the maximum number of key sets resulting from the set operations union and intersection, used to combine two or more different key sets. The intersection of the key for two or more relational database tables is essentially the relational join operations. This method can perform the relational join operations in a much faster and efficient method than presently utilized joined operations. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood in connection with the accompanying drawings in which: FIG. 1 is a general diagrammatic representation of an Internet communication system that, as used in the prior art, uses information handling nodes and network addresses for each host that must be changed as the host moves from one communication network to another thereby requiring a complex and cumbersome system to enable data communication from a message transmitting host to a system receiving host; when modified by the present invention, the system of FIG. 1 enables a message routing system using a message format having an internal logical or physical structure that is totally independent of the message receiving host location address; FIG. 2 is a schematic representation of the circuitry in an individual system node using parallel processing to detect the address of the next node or nodes in the system that are to receive a packet of information; FIG. 3 is a schematic representation of an alternate circuit using serial processing at any particular node in the system to determine the address of any other node or nodes that are to receive the data packet; and FIG. 4 is a diagrammatic representation of the circuitry for enabling the message format used by the routing system to be totally independent of the internal logical or physical structure of the address of the receiving host to whom the message format is being routed and further illustrates the manner in which a destination address or source address can be compressed to provide a usable index for accessing the address directory. FIG. 5 is a schematic representation of components of an associative memory module. FIG. 6 is schematic representation of a circuit for learned key logic for the associative memory of FIG. 5. FIG. 8 is a schematic representation of a circuit implementing symbol use count logic and delete key logic for the learned key logic circuit of FIG. 6. FIG. 9 is a schematic representation of a circuit embodying a second method of implementing a method for adding keys to the associative memory of FIG. 5, comprising add key logic component of the learned key logic of FIG. 6. FIG. 10 is a flow diagram describing the operation of a create new index logic component for the add key logic circuit of FIG. 9. FIG. 11 is a flow diagram describing the operation of a change old index value component of the add key logic of FIG. 9. FIG. 12 is a continuation of the flow diagram of FIG. 11 describing the operation of add the change old index value component. FIG. 13 is a continuation of the flow diagram of FIG. 12. FIG. 14 is flow diagram describing the operation of a save new index logic component of the add key logic of FIG. 9. FIGS. 15A and 15B are a flow diagram describing a method for assigning index values to an entire key set. FIGS. 16A, 16B and 16C are a flow diagram describing another method for assigning index values to an entire key set. FIG. 17 is a flow diagram describing a method for assigning an index value and expanding the directory to accommodate the new index value. FIG. 18 is a flow diagram describing a method for removing an index value and contracting the directory to accommodate the removed index value. FIG. 19 is a schematic representation of a circuit implementing symbol use count logic, maximum suffix logic, minimum suffix logic and delete key logic for the method of FIG. 16. FIG. 20 is a schematic representation of an alternative embodiment of an associative memory module. FIG. 21 is a schematic representation of a circuit for learned key logic for the associative memory of FIG. 20. FIG. 22 is a schematic representation of a circuit implementing symbol use-count logic and delete key logic for the learned key logic circuit of FIG. 21. FIG. 23 is a flow diagram illustrating the method for assigning index values to an entire key set group, including all invalid symbol values. FIG. 24 is a schematic diagram for an associative set processor and its included circuitry. FIG. 25 is a flow diagram of a union function for use with the associative set processor of FIG. 24. FIG. 26 is a flow diagram of a intersect function for use with the associative set processor of FIG. 24. FIG. 27 is a flow diagram of a mask function for use with the associative set processor of FIG. 24. FIG. 28 is a block diagram illustrating the use of an associative set processor to combine a plurality of use count tables. FIG. 29 is a block diagram illustrating the preparation of a result record memory from a plurality of results tables. FIG. 30 is a flow diagram illustrating the symbol sequence scanner logic of FIG. 29. FIGS. 31A thru 31D are flow diagrams of the highest thru lowest order bank functions. DETAILED DESCRIPTION OF THE DRAWINGS There are many communication networks existing today which are independent entities with respect to each other such as shown in FIG. 1. Each system 1-5 uses a particular hardware technology appropriate for its own communication problems; some use high speed networks; others use slower speed networks to interconnect machines. There are long haul networks and local area networks (LANS). There are shared media networks such as ETHERNET, TOKEN RING, TOKEN BUS, FDDI and the like, each of which has a different physical media protocol. Each of these network information systems may have its own protocol for handling information within the system. When electrical wires or cables are used to couple shared media networks, the size of the net is limited by signal attenuation to a few hundred meters; thus, the name Local Area Networks. There is no reason to limit the area of coverage other than the restrictions of the media itself. With the increased use of fiber optics, the span of these shared media networks is expanding to several kilometers and eventually will be able to span the entire continent. In the prior art, when an external device or host such as an aircraft 10, ship 12 or other receiver/transmitter (transceiver) station is communicating with anyone of these systems 1-5, it must have an identification of its own which is recognized by the protocol of the system with which it is communicating. In such systems, if aircraft 10 wishes to communicate with ship 12, aircraft 10 must transmit into the system, among other things, a fixed address of the message receiving ship 12. The protocol of the system can then use the address information to route the message through the system to the ship 12 at the address indicated. However, when a host passes from one communication system to another, the address code of that host must be changed to be conformed with or admitted to the new communication system. Thus, if a host passes from an FDDI to an ETHERNET system, the address code of the host must be changed in order to enable the new system to accommodate it. This change may require a great deal of manipulation of data within the system and require expensive additional equipment to enable the appropriate changes to be made. Further, by the time one host (ship 12) sends a message to the last known address of the moving host (aircraft 10), the moving host may have entered the range of a new communication network and have a different address code thereby causing a problem in receiving the message sent with a network dependent address from the message sending host. The present invention modifies the system of FIG. 1 to overcome the disadvantages of the prior art by allowing each host to have a fixed unique identification code instead of an address code which changes to identify itself with whatever communication network it may operating. With the present invention, if host A passes from a first communication network system to a second network system (as for instance aircraft 10 flying from communication network 1 to network 2) host A may be located by host B (ship 12) who simply transmits into the communication routing system the unique identification code of the host A with which it desires to communicate. It does not know where in the system, or in a plurality of interconnected communication systems, the host A is located. The interconnecting systems shown in FIG. 1 include a plurality of nodes 16, 20, 24, 26, 30 and 32 forming multipath connections between the plurality of network communication systems 1-5. The nodes can interface with each other even though they are in different communication systems simply by using protocols and procedures that are well-known in the art. If aircraft 10 desires to contact ship 12, it simply transmits a message format including its own unique code and the unique identification code for ship 12 to the nearest system 14. The receiving system 14 sends the message to node 18 which checks its memory tables to determine if it has stored the address of the last node (26 or 32) communicating with ship 12. If not, it stores the unique identification code of aircraft 10. It also forwards to all interconnecting nodes, except the one from which the message was received, 26 and 32 in this case, the message including the identification code of ship 12 as well as the identification code of aircraft 10. In like manner, each of the interconnecting nodes 26 and 32 checks its memory storage tables to see if it has received and stored the identification code for either aircraft 10 or ship 12. If not stored, it stores the unique identification code of aircraft 10 and the address of the forwarding node, and forwards that information to the succeeding nodes. Thus node 26 forwards that information to nodes 20 and 24 but would not forward it to node 32 since node 32 is also coupled to node 16 which has that information. Node 20 will be updated by node 26 since it is the closest node. Eventually, ship 12 will contact its nearest node 20 coupled to communication network system 5 through radio receiver 18 to identify itself. Source node 20 has the unique identification code for aircraft 10 stored in its memory table and will store the identification code and received route for ship 12 in its memory table. Node 20 will now contact the nearest node 26 from which it received the identification code for aircraft 10 and couple ship 12 to that node. Node 26 again will check its memory bank and find the nearest node from which it had received the identification code for aircraft 10 (node 16). A communication path is thus completed between aircraft 10 and ship 12 and they can communicate with each other even though initially one did not know the location of the other in the system. It will be noted that in this case there were no specific address locations of either aircraft 10 or ship 12 in any of the message formats that were transmitted or received. They simply contained the identification code of the message source and message receiver that was stored by the nodes and the addresses of each node in the path having that information, and the information was recalled as necessary to establish communication paths between aircraft 10 and ship 12. If ship 12 is moving and passes from the control of a first network communication system 4 to a second network communication system 5, the nearest node 32 in the first communication system 4, after a predetermined period of time, drops from its memory bank the identification code and routing information of ship 12. However, the transmission by ship 12 of its identification code to the nearest node 20 in the second communication system 5 is recorded by that node and transmitted to the other nodes throughout the interconnected system so that each node now knows the updated location of node 20 that is nearest to ship 12. In that manner, either aircraft 10 or ship 12, even though either or both are moving, can continually communicate with each other through an interconnected system of communication networks without having the specific system address of the other. Since any given node may receive information from one or more nodes, standard protocol is used to determine the node from which the given node first received the information. That would be the closest node. If, in the event of a transmission back along that path, it was found that the closest node was for some reason out of the system, it could then pick one of the other possible routes and send the information to a different node along one of those routes. Further, each of the nodes must be able to recognize when a message is for a single node (unicast), a group of nodes (multicast) or all nodes (broadcast). Such requirements can be accomplished by systems that are already well-known in the art. Further, each node is an information source to some nodes and an information destination for other nodes. Thus, each node has to keep a source index table and a destination index table. See FIG. 2. When aircraft 10 attempts to contact ship 12, aircraft 10 transmits into the nearest node its own identification code as well as the identification code of ship 12. The nearest node stores the source (aircraft 10) identification code in a source index table and in a destination index table. If a node has the destination identification code stored, it also has stored the address of the node from which it received that information in both its source protection record and destination route record. Of course, it may have received that information from several nodes and the addresses of all of those nodes are stored as sources and destinations. The source protection record, when combined with the destination route record, eliminates the routes to all of the other nodes except the nearest route through the use of a buffered routing logic circuit. Thus a path is connected between the two closest nodes for carrying the packet of information from aircraft 10 to the next nearest node. This process repeats in each node until the information packet arrives at ship 12. Referring again to FIG. 1, as aircraft 10 is detected by receiver 14, the identification code information transmitted by aircraft 10 is fed into a communication network or system 1 and node or router 16 notifies the other nodes or routers in the system of the identification code. In like manner, as receiver 18 detects ship or vessel 12, communication network or system 5 updates node or router 20 with the ship 12 identification code. It, in turn, notifies the other nodes or routers within the complex communication network or system. As receiver 22 detects the movement of aircraft 10 into its area, communication network or system 2 updates node or router 24 which then updates the other nodes or routers within the system. Node 16 no longer receives information from system 1 but now updates its information from system 2 through nodes or routers 24 and 26. As aircraft 10 continues to move, receiver 28 will detect aircraft 10 and notify router 30 through system 3. Again, router 30 notifies the other nodes or routers within the system. Node or router 24 will no longer receive its information from network 2 but will be updated through router 30 as to the identification code of aircraft 10. The problem with such vehicle movement with the prior art system, as stated, is that each of the communication systems 1-5 are different networks and may use different types of media access protocols for operation which require the network address of the moving vehicle to be changed. Thus many communication networks service their stationary and mobile users with a wide variety of media ranging from satellite links, high frequency radio, local area networks (LANS) and dedicated point to point circuits as illustrated in FIG. 1. Shipboard LANS, including SAFENET I (IEEE 802.5 Token Ring) and SAFENET II (ANSI X.3-139FDDI), are used to support command, control, communications and intelligence in certain systems. The use of standard ISO (International Standards Organization) Internet protocols and the development of very high performance, low latency packet-switched gate ways between these networks is critical to reliable communications between mobile vehicles. As stated, in the prior art, the aircraft 10 must have assigned to it a code representing its physical address with respect to communication system 1. Physical addresses are associated with interface hardware. Thus, moving the hardware interface to a new machine or replacing a hardware interface that has failed changes the physical address of a particular host. In like manner, as the aircraft moves from system 1 to system 2 in FIG. 1, because system 2 may operate with a different media access protocol, the coding of the physical address of aircraft 10 must be changed to meet the standards of system 2. This means that if ship 12 attempts to communicate with aircraft 10 using the physical address at the last known address location in system 1, it cannot locate aircraft 10 without a new location code because aircraft 10 has moved into a new communication system network and has changed its physical address code. The novel system of the present invention modifies FIG. 1 to provide an Internet routing table that uses a flat logical address structure to provide fast and efficient route processing of both multicast and unicast message traffic. In the present system, the physical address structure is removed from the design and operation of the Internet routing by treating the message addresses as a symbol string without predetermined internal structure and processing them as if they are a unique identification code representing the host. This approach is made possible by employing an arithmetic code compression technique as a hashing function for the routing table access method. By managing and manipulating logical network addresses within the system, mobile end-systems can keep the same network identification code (not physical address) as they move from communication network to communication network. Similarly, group or multicast addresses may be allocated without regard to their physical network connection. Thus, considering the use of the present system with the networks of FIG. 1, aircraft 10 and ship 12 maintain the same identification code even though they move from one of the networks 1-5 to another. When aircraft 10 is in communication with network 1, node 16 notifies all of the other nodes 20, 24, 26, 30 and 32 in the system that node 16 is in contact with aircraft 10. In a like manner, when ship 12 is in communication with node 20 through network system 5, node 20 notifies the other nodes in the system that it is in communication with ship 12. If aircraft 10 moves to network system 2, node 24 updates all of the other nodes in the system and their data is changed to identify node 24 as the new node in contact with aircraft 10. This system then enables each node to store data representing the address of the last node communicating with a particular mobile vehicle and not the physical address of the vehicle. This allows communication from aircraft 10 to ship 12 throughout the various communication systems without either aircraft 10 or ship 12 being required to change network addresses as they move from access point to access point and without knowing the specific network location of the other. Each of the nodes 16, 20, 24, 26, 30 and 32, may utilize any well-known means in the art for providing point-to-point and demand assignment access protocol message transmissions to communicate with each other. There are various systems well-known in the art which allow communication network systems using one protocol to communicate with another system using a second protocol and they will not be described here. The present system may be utilized as a Media Access Controller (MAC) multi-way switch in each node as an electronic module which detects the physical layer node address fields of the data packets arriving from one node and uses those addresses to route (switch or bridge) the packet to another node which is a path to the physical station with a particular node destination address. The MAC level multi-way switch examines the bits which constitute the node destination address field to identify which, if any, of the nodes connected to the switch should be presented the message packet for transmission. This operation is often called “destination address filtering.” A number of shared media networks previously mentioned have been standardized for common use and inter-operation of different vendor equipment. The most common of the LAN standards are ETHERNET, TOKEN BUS, TOKEN RING AND FDDI. Each of these shared media networks sends information as a variable length sequence of bits called a packet. Each packet has a fixed number of the initial bits transmitted which are dedicated both in position and size to a packet header. This header contains a destination address field and a source address field along with other housekeeping information bits. All four of the LAN standards listed above employ the same number of bits with the same meaning for both the source and destination address fields, although the housekeeping fields are different for each. Shared media networks operate basically in the same way. The media is shared so only one node or station (one MAC) may transmit at a time and all of the other nodes or stations listen. In order to identify the recipient of the message, a destination node address is located in a specific location at the beginning of each information frame. Each listening station examines these destination node address bits to determine if the packet is for it. The receiving station (the destination node) needs to know where to send a response to the received packet and thus the packet has source node address bits at a specific location (usually just after the destination node address). The major differences in the various LAN standards are transmission speed and the scheme each uses to guarantee that only one station at a time is allowed to transmit on the media. The Media Access Controller (MAC) is the defined entity in each of the above-listed LAN standards which connects the computer side logical level interface to the physical media. MAC isolates the logical data stream from the physical media so the circuitry on the computer side of the MAC only deals with the header and information bits. Thus, the MAC-level switch or bridge is an electronic module which connects similar or dissimilar physical shared media networks each of which employ identical addressing field definitions. The switch transfers information packets originating from stations or nodes on one network to destination stations or nodes on another network. If station A on a shared media network desires to send a packet to station F, then station A places codes representing “F” in the destination node address field and “A” in the source node address field of the packet header of the packet being transmitted. When the MAC of station A gains access to the shared media, it transmits the packet along with other packets it may have queued for transmission. Other connected MACs all receive the packet header and examine the destination node address field. Station F recognizes the address as his own and receives the remainder of the packet. All of the other stations on the network see that the packet is not for them and disregard the rest of the packet. Neither the source node address nor the destination node address are changed in any way. All of the standard LANS listed above have a group addressing scheme where one station may send one packet simultaneously to many other stations belonging to the group. This feature is called multicast and takes advantage of the shared media to send the packet just once rather than having to send an individual packet to each station in the group. Suppose station A wishes to send a packet to all stations in a group identified as 110 which includes stations identified as F, G and N. Station A would then put the group “110” in the destination node address field and “A” in the source node address field. When MAC A gains access to the first network, it transmit the packet. Stations F, G and N would then detect their group address and accept the packet. Other MACs would not. FIG. 2 is a schematic diagram of a MAC switch 38 which couples a Media Access Controller 34 at one node level to desired Media Access Controllers 40, 42, 44 and 46 at other levels. The MAC level switch 38 shown in FIG. 2 examines the source node address field of the incoming information to determine if any or all of the other connected nodes are protected from receiving the information from the incoming source. This operation is often called “source address filtering.” Thus in FIG. 2, MAC 34 may transmit data and clock information on lines 36 to switch 38 which determines which of the destination MACs 40, 42, 44 and 46 are to receive the information. In switch 38, the data and clock signals on line 36 are serially coupled to a source address shift buffer 48 and then to destination address shift buffer 50. The data is then transferred from destination shift buffer 50 to delay buffer 52 which is a first-in, first-out device. The output of delay buffer 52 on line 54 is coupled to the buffer routing logic 56 which generates an output on lines 58, 60, 62 and 64 depending upon the destination address filtering operation performed by the switch 38. The Media Access Controller switch 38 transmits or forwards data it receives, and accepts data for transmission as eight parallel data bits called a data octet. It processes address symbols which are a fixed number of consecutive bits from the address bit string and may be from two to any number of bits in length. One size symbol is the “eight” bit octet which is the symbol size used in the address routing table circuits presented in FIGS. 2 and 3. The number of symbols in the maximum address length to be processed for a particular implementation is a design and management decision. The examples presented in FIGS. 2 and 3 use six octets as the maximum address length, since this is the length of the IEEE standard physical layer (MAC level) address used by Ethernet, Token Ring, and FDDI. The International Standards Organization (ISO) network layer (IP.ISO 124) employs a variable length, up to 20 octets, for the source and destination address 128 and 126, as shown in FIG. 4. The designs shown in FIG. 2 and FIG. 3 would be able to process IP.ISO 124 addresses 126, 128 up to “six” octets in length. MAC 38 is responsible for aligning the data properly on the octet boundaries such that the destination and source addresses start and end on octet boundaries. Furthermore, in the LAN standards listed above, the source address field always immediately follows the destination address field and the two are always the same size. A common size for the address fields is 48 bits or 6 octets each. The address detection logic examines both the destination and source address fields represented by the octets shifted into buffer 48 and buffer 50. Six octets are in each buffer. When the twelve octets are all stored, each octet is used as an address into a 256 element index table for that address octet position. This requires six destination index tables 66 and six source index tables 68. The output of these tables (the contents of the location addressed by each octet) is then arithmetically combined in combiners 70 and 72. One method of arithmetically combining these outputs adds the six outputs of the source index table 68 to compute the source index 74. It also adds the six destination table 66 outputs to compute the route index 76. The source index 74 is used as the address into the source protect table 78 and the output of that location is the source protection record 80 which is coupled to the routing logic 82. Similarly, the route index 76 is used as the address of a location in the destination routing table 84 and the contents of that location is coupled to route record 86. The outputs of the protect record 80 and route record 86 are used by the routing logic 56 in a well-known manner to determine which destination MAC is to receive the message. FIG. 2 may also operate as an internet level switch (router) 38, operating on IP.ISO header 124 destination 126 and source addresses 128 by shifting in the IP destination and source addresses. When aircraft 10 in FIG. 1 transmits a packet with its unique internet source identification code to one of the nodes in a network, the source address of aircraft 10 is shifted from source address buffer 48 (FIG. 2) into learned address logic 88. If that source address is a new address not stored in source index table as indicated by a zero detect, it is stored in both the source and destination index tables 66 and 68. If, after a predetermined amount of time, that information is not confirmed by a subsequent transmission, the learned route logic 94 generates an output 97 to the learned address logic 88 telling it to delete the address from the both source and destination index tables 66 and 68. This means that the aircraft 10 has moved to a different network and may be updating a new node in the new network. Subsequently, the new network node then sends a message to switch 38 in the old node and stores the source address of the new node in the route record 86 associated with the unique source address for aircraft 10. By keeping track of the source addresses of the various nodes that are transmitting information concerning a particular identification code, learned route logic 94 causes the destination routing table 84 to delete old source nodes as destinations for particular incoming data packets and add the addresses of new nodes as the destination. The source protect table 78 in each node stores the source protect record 80 (also called the MultiCast Record List 134 in FIG. 4), which has information defining a shortest path from a particular source to that node. This shortest path information is computed from the messages received from forwarding nodes using a shortest path spanning tree algorithm well known in the art. The source protect record 80 may be modified by management decision to prevent messages from a particular source identification code from being forwarded on particular paths to other nodes. The destination routing table 84 (also called the Outbound Record Linked List 132 in FIG. 4) contains the shortest path information from this node to the current connected nodes for each unique identification code currently stored in the source and destination index tables. The current route record 86 is this shortest path information for the destination address currently in buffer 50. This information is computed from the messages received from forwarding nodes using a shortest path spanning tree algorithm well known in the art. Thus, in FIG. 1, if node 26 has received information from source nodes 16, 24 and 32, and it receives a data packet for node 20, the protect record 80 from the source protect table 78 and the route record 86 in FIG. 2, when processed by the buffered routing logic 56, will prevent node 26 from transmitting the information back to nodes 16, 24 and 32 but allow it to be transmitted to the destination node 20. Thus, the information from an incoming node or MAC 34 to a particular switch 38 may be transferred to the desired destination MAC 40, 42, 44 or 46 by the buffered routing logic 56 in the manner explained. In FIG. 2, the address detection logic employs separate tables and arithmetic processing elements for both the source and destination address detection. While this approach allows the arithmetic processing and record table access to be relatively slow the slower elements are not sufficiently economical in price to be cost effective. Neither does the circuit of FIG. 2 utilize the fact that because the data octets arrive sequentially, they could be processed through the index look-up table and partial arithmetic computed each octet time. FIG. 3 is a circuit diagram of an alternate logic layout for serial processing of the incoming data by a switch 96 which is similar to switch 34. The data octets arrive sequentially and FIG. 3 discloses a logic layout which uses one bank of index table memory 98, one bank of address record memory 100 and one arithmetic computation unit 102 to accomplish both source and destination address detection. In this approach, the octet data bits are coupled serially into octet register 104 and are used as the low order address bits into the index table 98. A byte counter 106 which counts the address octets from one to twelve as they arrive in the octet register 104 is used as the high order address bits into the index table 98. From byte count one to six, the arithmetic unit 102 partially computes the final index with each output from the index table. After byte count six, the computation for the destination address mask index is complete and transferred to the index buffer 108. The arithmetic unit 102 is then reset and the six octets of source address are computed. By the time the source protection record index 110 has been computed, the data in destination route record 112 has been loaded into its output buffer on line 114. The source protect record 110 is then accessed from a second bank of the mask memory 100 using the count twelve signal on line 116 as the high order address bit. This sequential detection approach shown in FIG. 3 places special performance requirements on the index table memory and each reiteration of the arithmetic computation. That is, the access to the index table 98 and the partial computation with the table output each must be complete in less than one octet time. However, the computation is delayed one octet clock time behind the table access. Each of these timing requirements is within the available speeds of commercially available VLSI computer memory and arithmetic components. Current DRAM memories regularly run at less than 300 nanosecond access times making all but the FDDI real-time address routing practical with DRAM parts. Static RAM memories are currently available with 50 nanosecond and faster access times which makes even FDDI routing realizable. The address record memory 100 is only required to be ⅙ the speed of the index memory 98 since there are six octets between completion of the first and second record indexes. The source protect record 110 and the destination route record 112 feed into the buffered routing logic 56 of FIG. 2 to select the outbound path (MAC) for the message. The record memory indexes may be computed by adding and accumulating the succession of six index table values to compute the mask memory index. Integer add/accumulator devices of 16 to 32 bit precision are currently available which execute a single add function in less than 80 nanoseconds. Many 16 and 32 bit microprocessors have integer add/accumulate times under 500 nanoseconds. The address directory access circuit overview is shown schematically in FIG. 4. The arriving data packet contains a preamble 118, the first protocol layer 120 which is the Media Access Control protocol header containing the physical media destination address of the MAC receiving the packet, the second protocol layer 122 which is the logical link control and the third protocol layer 124 which is the IP.ISO Internet layer. The remainder of the packet contains the message data and housekeeping information. The third protocol layer 124 contains the unique code identifier of the receiver as the destination address data 126 and the unique code identifier of the transmitter as the source address data 128. The physical link data 120 is the actual communication channel hardware with its associated coding and modulation techniques. Physical link 120 is separated from the Internet data 124 by a combination of computer interface hardware and software called the logical link control entity data 122. Besides logically isolating the Internet layer 124 from the physical layer 120, the logical link control 122 provides a capability to multiplex packets from various higher level protocols such as TCP/IP, DECNET, and ISO/OSI over the same physical link. Each different protocol is assigned a different logical service access point (LSAP). Each LSAP is serviced by a separate set of software providing processing for each protocol as is well known with prior art. It is thus possible that one physical Internet router might be required to route packets of different protocols and therefore require two or more Internet software processes. This prospect is likely in an environment where existing networks using the TCP/IP protocols are phased over to the ISO/OSI protocols. This invention allows the same routing table access method to be employed by multiple protocols. The IP/ISO Internet protocol data 124 provides a connectionless or datagram service between nodes on a network. Data to be sent from one node to another is encapsulated in an Internet datagram with an IP header specifying the unique global network addresses of the destination and source node. This IP datagram is then encapsulated in the logical link control 122 and physical layer protocol headers 120 and sent to a router or node. The router strips off the incoming physical header 120 and the LLC header 122. It looks up the destination and source addresses 126 and 128 in its routing table 130, selects the appropriate outbound link, or a plurality of outbound links in the case of a multicast group destination address from table 132 and reduces the plurality of outbound links using restrictions from table 134 in the case of a multicast transmission and passes the IP datagram packet to those selected channels for LLC encapsulation and transmission. With multicast datagrams, the router must determine which outbound links represent the shortest path from the multicast source to the destinations which are members of this particular group. Without this source filtering, well-known in the art, a destination station within a group might receive many copies of the datagram transported over different paths. Such multicast “flooding” wastes networks bandwidth and causes unnecessary congestion on busy segments of the network. The ISO Internet Protocol (IP) header 124 has a number of fields. From the IP header format 124 it is apparent that the starting position and length of both the destination and source address fields are known or can be determined from the information within the IP header. The proposed routing table directory structure 130 needs only to know the length and values of the address octets to locate a unique table entry for that address. This novel directory access technique does not rely on any known structure of the address field other than knowing that it is a sequence containing a known number of symbols. It can be seen from the discussion of FIG. 4 that the circuit therein could be used in an alphanumeric system such as, for example only, a library wherein an author and/or book name could be used to access a data table storing all books by author and title. In that case, destination address 126 in FIG. 4 would be an alphanumeric string of data representing the author's name and/or book titles. The arithmetic compression techniques illustrated by blocks 138, 142, and 144 could be used to compress the alphanumeric string as needed to obtain an index 136 which would select the appropriate address in table 130 which would contain all of the library material by author and book title. The selected information could then be obtained through routing tables 132 and 134. Since the destination and source address are from the same network address space, they have an identical form and can use the same directory. Source addresses must be individual nodes and cannot be group addresses. To constrain the Internet overhead, the initial versions of the ISO Internet have been restricted to 16 octets maximum. This is a huge number of possible addresses on the order of 1036 and should be more than adequate for many years of global Internet operation. Routing is accomplished by maintaining a routing table directory 130 at each node in the network as is well-known in the art. These tables are indexed by the destination and source address and contain information indicating which outbound communication links reach the destination node or nodes in the case of a multicast group address. The Internet routing task or program accesses the table 130, gets the outbound route information, analyzes the route information and queues the packet for transmission on one or more of the outbound ports stored in tables 132 and constrained by the records in 134. For all addresses, the Internet task also accesses the source address table which contains information defining which outbound ports should not be used for a multicast transmission to this group (destination address) from a particular source and other source filtered information. Efficient multicast transmission requires some evaluation of the shortest route to all members of the group from the source location. The present system utilizes the directory 130 and routing table structure 132 and 134 for the already existing Link-state approach. Other existing methods have similar needs and could be incorporated into the design if another routing method is employed by a network. The novel Internet routing task set forth herein is self learning. No information about any existing addresses or their routes need be stored in the task prior to start up. The routing information is entered into the routing table 130 as a result of the Internet routing protocol activity or network management protocols. When a router starts up, it sends out “I am here” messages using the Internet routing protocol. All of the adjacent routers or nodes send back IP routing protocol packets which, when combined with the input bound channel, contain the information necessary to fill in the routing tables for all active Internet addresses. The novel system uses arithmetic coding of the directory index 130 as shown by the diagrammatic illustration in FIG. 4. Arithmetic coding is a powerful technique for obtaining the near minimum entropy compression of a sequence of data bits. Since a network address is just a sequence of binary data bits of known length, the minimum entropy compression of all the combinations of bit strings represented by all of the active network addresses should produce the shortest number of bits which would uniquely identify all of the addresses. This encoding could then be used as an index 136 into the routing directory 130. Essentially arithmetic coding uses the distribution statistics of the symbols (in this case octet values) to divide a unit space into a unique fraction based on the sequence of symbols (octets) presented. As each symbol (octet) is presented, the unit space is subdivided into a smaller range. Symbols (Octets) with higher probability of occurrence reduce the range less than those with small probability, causing fewer bits to be used in encoding the higher probability octets. A detailed discussion of such method including program fragments and examples is disclosed in a paper published by Witten, Neal, and Cleary, Communications of the ACM, June, 1987. This paper is oriented to adaptive encoding and decoding of data streams and does not deal with the specific application of address detection. However, the method disclosed in that paper can be used for that purpose. Thus in FIG. 4, the destination address 126 is compressed by the arithmetic code process 138 to obtain an integer 140 which represents the address. If further compression is needed, the integer can be compressed through truncation 142 by methods well-known in the art and further compressed if needed by hashing 144, a technique also well-known in the art. The resulting index 136 is then used to find the unique address in the compressed address directory 130. The routing switch designs 38 and 96 shown in FIGS. 2 and 3 are specific implementations of the novel arithmetic compression process employed by this invention. After all the address octets have been processed, the last value is then the compressed value of the input address octet string. It is sufficiently compressed to be useful as a routing table index. The novel index table construction and address compression processing of this invention takes place as follows: Addresses can be fixed and variable length bit strings embedded in the Media Access Control (MAC) 120 and Internet protocol (IP.ISO) 124 headers of the received communication packet. The maximum size (Address_length) of an address which can be compressed is set by a management decision and the physical design of a particular implementation of the process. Symbols are consecutive sets of adjacent bits taken in sequence from the address bit string. Successive symbols may have a fixed overlap incorporating a fraction (Overlap fraction) of the same bits from the address bit string in an adjacent symbol. All the valid bits in the address string must be included in symbols processed. For a particular implementation of the process the symbols are a fixed number of bits in length (Symbol_size) which can vary from 2 bits to any number of bits. In the embodiments presented in FIGS. 2 and 3, a symbol is an “eight” bit octet. The number of symbol positions in an address string (Num_symbol_positions) is the length of the address string in bits divided by the symbol size minus the product of the symbol size and the overlap fraction. Thus, Divisor=Symbol_size−(Symbol_size×Overlap_fraction) Num_symbol_positions=Address_length/Divisor An address index table (66, 68 and 98 in FIGS. 2 and 3) has a number of banks equal to the number of symbol positions in the address string. Each bank of memory in the address index table has a number of memory locations (Bank_size) equal to. “two” to the power of the symbol size. Sub-index values are stored in the non-zero locations of each bank. Thus, Bank_size=2 raised to the Symbol_size power. The address index table size (AI_table_size) is the product of the bank size (Bank_size) and the maximum number of symbol positions (Num_symbol_positions) being processed. The maximum number of non-zero entries, called the allowed maximum count (Allowed_max_count), in each bank of an address index table is set by a management decision. Addresses may be encoded into the address index table until the number of non-zero entries reaches the allowed maximum count for any symbol position. If the encoding of any address value into the address index table results in the number of non-zero entries in one of the symbol positions exceeding the maximum allowed number of entries, then the address cannot be encoded into the table until another entry in this symbol position is removed, that location made zero, and the current count decremented by one. Alternately, the allowed maximum count may be increased by a management decision and all the existing address bit strings must be recoded into the address index table using the new maximum non-zero entry values. The address index tables (66, 68 or 98) are then incrementally filled in with sub-index values as particular address bit strings are encoded into the address tables. This processing takes the following steps. Initially the table (66, 68, and 198 in FIGS. 2 and 3) is entirely filled with zero entries and the value of all locations in the table is set to zero. (1) A counter (Current_count) is established by the learned address logic 88 for each symbol position to keep track of the number of non-zero entries in this bank of the address index table and these counters are initially set to zero. In order to keep track of the number of addresses using a particular non-zero location in the address index table, a use counter is established in the learned address logic 88 for each non-zero location in each bank of the address index table. (2) The allowed maximum non-zero entries value for each symbol position is obtained from a management decision. (3) A range value (Range) is computed for each symbol position. The first range value is computed by setting the range for some symbol position to the allowed maximum count for that symbol position. The range value for the next symbol position is the range value for the previous symbol position times the allowed maximum count for this symbol position. The range value for each symbol position is the product of the range value of the next previously computed symbol position and the allowed maximum count for this symbol position. The order of the symbol positions used to compute the range values is only important in that the decoding operation used to recover the original address before encoding to an integer value must use the same symbol order as that used to compute the range values. The sequence of range value computations from the last address symbol to the first address symbol must be used to preserve hierarchical structure of the structure of the original address being encoded. Range (I)=Range (I+1) times Allowed_max_count (I) Each symbol from an address bit string to be encoded into the address index table is processed in the same sequence as that used to process the address symbols during receipt of the packets from a transmitter for routing table access. (1) Use the numeric value of the symbol as the address of the location in this symbol's bank of the address index table (66, 68 and 98). (a) If the existing entry in this location of this bank of the address index table is not zero, then increment the use count for this location and no further processing of this symbol is required and the next symbol may begin processing. (b) If the existing entry at this location in this bank of address index table is zero, then non-zero entry value is computed by (1) incrementing the current count for this symbol position, (2) checking to be sure the incremented current count is less than or equal to the allowed maximum count for this symbol position, and (3) (if the count is not greater than the maximum) computing the value of the incremented current count multiplied by the range value for this octet position and divided by the allowed maximum count for this position and storing this value in this location in the address index table and setting the use count for this location to “one”. If the incremented current count is greater than the allowed maximum count for this symbol position, then this address cannot be encoded into the address-index table and the management entity is notified that the address index table has overflowed unless another address is removed from the table making a use count go to “zero” and reducing the current count for this symbol position. (2) Continue processing address bit string symbols until the entire address has been encoded into the address index table by having for each symbol in the address a non-zero value for that symbol value location in every symbol position bank of the address index table. Address bit strings embedded in the incoming packets are compressed in the combine table outputs 70 and 72 in FIG. 2 and in arithmetic computation 102 of FIG. 3 to an integer value by adding together the stored values from the address index table bank for each symbol position where the symbol value is used as a location address into the bank for that symbol in the address index table. If any index table value accessed is zero, the processing stops and the zero detect 90 is activated. This zero indicates the address has not been encoded into the address index table. If the number of significant bits in the encoded integer are larger than the size of the compressed address directory 130, then truncation 142 (removing some low order bits) and Modulo N hashing 144 (removing some of the high order bits) may be used to reduce the size of the encoded address integer to the number of locations in the compressed address directory 130. To decode the original address from the encoded integer and to remove the encoded address from the address index table, the decoding process starts with the symbol position for which the Range value was set to the allowed maximum count and proceeds in the same symbol sequence as the Range values were computed. (a) Starting with the first range symbol position (the position that was set to the allowed maximum count), the encoded integer—before truncation or hashing—is searched in the low order bits for a value between 1 and the allowed maximum count for the symbol position. The result of this operation is the value obtained from the address index table for this symbol position and that table sub-index value was added to the integer value to create the final integer number. (b) The location for this remainder value in this symbol position bank of the address index table is found, the use count for this location is decremented by “one”, and the position of this location in the bank is the original symbol value for this symbol position. If the decremented use count is zero, then the current count is also decremented by one. If the current count reaches zero, then no addresses are encoded into this position in the address index table. (c) To decode the second symbol in the sequence of symbol positions used to compute the range values, the value from the previous operation is subtracted from the integer value. The resulting integer value is then searched for the low order bits for a sub-index value between the previous range value and this range value. This sub-index value is the value obtained from the address index table for this symbol position which was added to the integer value to create the final integer number. The location for this sub-index value in this bank of the address index table is found, the use count for this location is decremented by “one”, and the position of this location in the bank is the original symbol value for this symbol position. If the decremented use count is zero, then the current count is also decremented by one. If the current count reaches zero, then no addresses are encoded into this position in the address index table. (d) To decode each successive symbol in the sequence of symbol positions used to compute the range values, the sub-index value from the previous operation is subtracted from the integer value used in the previous operation. The resulting integer value is then searched in the low order bits for a sub-index value between the previous range and the current range for this symbol position. The resulting sub-index obtained with this operation is the value obtained from the address index table for this symbol position which was added to the integer value to create the final integer number. The location for this sub-index value in this bank of the address index table is found, the use count for this location is decremented by “one”, and the position of this location in the bank is the original symbol value for this symbol position. If the decremented use count is zero, then the current count is also decremented by one. If the current count reaches zero, then no addresses are encoded into this position in the address index table. This process is repeated until the integer value is reduced to zero. The sequence of symbol values produced are the symbol values used to encode the integer from the original address bit string. From these symbol values the original address bit string can be reconstructed by placing the symbol values in their symbol positions in the original bit string. Thus there has been disclosed a data communication system which uses a routing table access method that treats network addresses as variable length symbol strings without internal structure—i.e., as flat addresses—to simplify the handling of mobile end-systems simultaneously connected to multiple access points. The system utilizes high speed, Media Access Control and Internet processes which handle multicast messages to multiple, mobile hosts. The technique is also applicable to real time database applications such as a network name service which relates a logical name (alphanumeric name) to its universal identification code. For example, an automatic telephone directory service could use this system to enable entry of a particular name and receive the telephone number of that name. Thus, the novel system allows one entity having a universal identification number to communicate with any other entity in the system having a universal identification number but whose physical location is unknown. Because the Internet router system is based on a flat logical address space, it provides efficient routing of both multicast and unicast packets independent of the internal network address format or structure. Further, reversible arithmetic code compression techniques are used to reduce the size of the network address index and dynamic hashing is used to reduce the size of the routing table directory. Importantly, a message address is used that is structure-independent of the location or network attachment of the message receiver. Referring now to FIGS. 5-9, two additional methods of constructing index tables are disclosed. The routing table access method and apparatus described in connection with FIGS. 2-4 has, as already discussed, real time data base applications other than the date communications network of FIG. 1. Those of ordinary skill in the art will readily recognize that the routing table access method and apparatus of FIGS. 2-4 describe an associative memory employed in context of a communications switching application. The possible applications of this same associative memory scheme are numerous and diverse; it is not confined to communications switching systems. For example, it has application in such diverse systems as those for on-line telephone directories, radar target tracking, and sonar signal classification—almost any system or application requiring or using high speed access to real-time databases where information is accessed with key values without knowledge of precisely where it is stored within a memory system. It is especially useful for systems utilizing very large key-spaces, when the number of keys that are actually used to access data records stored in memory constitute a fraction of the total number of possible keys. For these reasons, the two additional methods of constructing the index table will be described with reference to a generic application in a host system. Referring now to FIG. 5, this figure essentially illustrates the associative memory of FIG. 3, shown with the addition of learned logic 88 and 94 of FIG. 2. The only difference between FIGS. 2 and 3 are the manner is which symbols comprising the addresses are processed: in parallel in FIG. 2; and in serial in FIG. 3. The purpose of FIG. 5 is to introduce generic terminology for the associative memory of FIGS. 2-4. For example, the addresses, both destination and source, of FIGS. 2-4 are simply types of “keys”. A key is a unique string of bits that will be used to look up or access a “record” or a “key record”. The routing information or “address record” of FIGS. 2-4 is simply a type of “record”. A record is another, typically much longer and not necessarily unique, string of bits that the system in which the associative memory is located is trying to store, access, update or delete. In most applications, at least part of the key is found in the record. The key has a maximum predetermined length or number of bits, as previously explained, which are divided into “symbols” of predetermined length and positions. These symbols may or may not represent alphanumeric characters, as those of the ASCII code, or any other type of characters. The key, for example, may be part of a digitized waveform stored as a record. The symbols may also be overlapping—that is, share bits. There is no limitation on what the record and the key represent. They need only be a string of data values. An associative memory module 500, a preferred embodiment of invention, is used with a host system. One such host system, embodying an associative memory module, is the communications switching apparatus of FIGS. 1-4. The associative memory module receives from the host system a key on input line 501 in a sequence of key symbols, Symbol[i], where i=1 to N and where N is the number of symbols in a key. Associative memory 500 processes one key symbol at a time. Associative memory module 500 may also be reconfigured to process all the symbols of the key at the same time, in parallel, as shown in FIG. 2. A key symbol, when received, is stored in key symbol buffer 104. Symbol counter 106 counts the symbols as they are received so that the position where the current symbol is stored in the key symbol buffer 104 is always known. The value of the symbol counter is the current symbol position “i”. As represented by block 503, an address for index table 68 is generated from the position “i” and the value of the key symbol stored in the buffer 104. The position of the symbol within the key taken from the symbol counter 106 selects a bank, Bank[i], in key index table memory 68, and the value of the key symbol taken from buffer 104, Symbol[i], is the offset address within the bank. Key index table memory 68 basically stores a table of values, called key index values. The memory storing this key index table must then be divided, either physically or logically, into banks 1 to N, as shown. Each bank is, in turn, divided, either physically or logically, into offset addresses that a predetermined number of bits that store a key index value. The size or number of bits addressed by the offset must be large enough to accommodate the size of index values stored therein, and the number of offset addresses depends on the size of the key symbols. The number and size of offset addresses depends entirely on the application. The index table memory 68 is any type of memory capable of, at minimum, storing a table of values: for example, a random access memory (RAM) or a read only memories (ROM). There is no inherent limitation of the storage media, whether it is electronic, magnetic, optical or some other type. Nor is there any limitation on the hardware configuration of the memory. The only limitation is that it can be addressed as just described, while, preferably, meeting desired performance criteria. Generally, a very fast memory is preferable so that keys are processed as rapidly as is necessary for the application. For example, where k number of bits are required for storing an index value, a single k-wide memory chip is likely to be the simplest and quickest way of implementing the index table memory, presuming the chip is large enough. Minimal address decode circuitry is required. On the other extreme, use extensive address decoding circuitry may slow performance. Cost, size, and durability constraints, restrictions posed by operating environment and many other design criteria associated with a particular application will determine what type of memory is best suited for implementing the index table. For example, where, as in several of the embodiments of the invention, data is written to the index table memory during processing of a key, the memory must be randomly accessed. Where index table memory is not updated, Read-Only random access memory may be used. The data value or index that is addressed is read onto line 505 to arithmetic computation logic circuitry 72. Arithmetic computation logic is primarily comprised of a Modulo (P) adder, where P is approximately the number of logically addressable memory locations in key record memory 78. In the preferred embodiment, P is chosen to be a prime number. Arithmetic computation logic circuitry 72 is initialized or set to zero before receipt of the first symbol in a key is presented on line 501. As the index value is read onto bus 505 from the index table memory, symbol counter 106 provides an enabling or clock signal on line 507. The enabling or clock signal from the symbol counter is delayed by delay device 509 by a time greater than the access time required for the index table memory 68 but less than the period between symbols presented on input bus 501. When enabled, the arithmetic computation logic circuitry adds an index value on line 505 to a previously computed sum, in effect keeping running total. When the running total exceeds P, P is subtracted from the running total. The arithmetic computation logic circuitry thus performs a Modulo (P) addition of the index values stored in the index table memory for each symbol in the key to create a final sum called a record index. The record index is a data value that will be used as a logical address to the place within key record memory 78 in which the record corresponding to the key presented on input lines 501 is stored. Arithmetic computation logic circuitry also includes zero detect circuitry 90 for indicating that an index value received on line 505 from the index table memory 68 is zero. By definition, a zero value stored in an entry the index table for a symbol, as defined by its position within the key and its value, indicates that the symbol value has not been encoded into the index table and therefore no key record is stored in the key record memory 78 associated with the key that has been presented. The zero detect or “No Index” signal is provided on line 92 to the host system. The choice of zero as the value which indicates an index has not been assigned to that location in 68 is not critical to correct operation. Any bit pattern may be selected to indicate “no index” has been assigned. The index tables 68 are then initialized with that bit pattern and “zero detect” is changed to detect that pattern. Using bit patterns of all “zero” or all “ones” are convenient choices. Once the last symbol of the key is processed, the final sum or record index in the arithmetic computation logic circuit 72 is read to the record index buffer 74, also called a key record memory address buffer. This value is the key record memory address that is presented on address lines 517 to key record memory 78 in order to access the record associated with that key. An enabling or clocking signal on line 513 causes the record index buffer 74 to store the record index and provide it on address lines 517 to the key record memory 517. To generate the enabling or clocking signal on line 513, the enabling signal provided to arithmetic computation logic circuit is divided by N, the number of symbols in the key, by divider circuitry 515. Record memory 78 stores records of data that are accessed by presenting a key to the associative memory module 500 and decoding it into a record memory address as described above. Upon presentation to the record memory, the record memory address enables access of a record associated with the key and, with an appropriate read command (not shown) reads it onto output lines 519 to be stored by key record buffer 80 when enabled by a signal from delay element 515 (the delay element providing sufficient time for accessing the memory and reading out the record of data onto lines 519). In essence, therefore, a record of data desired by a host system using the associative memory module 500 is accessed by presenting a key associated with that data and generating an address where the record is stored in a memory from a specially encoded index table 68. The key is uniquely associated with that record of data, though the record of data is not necessarily uniquely associated with that key. How the record memory address is physically and logically constructed, as well as the form of the record memory address presented to the memory for access, are innumerable. The record memory address need only access the record of data associated with the key; how it does so depends on the memory chosen and the application. For example, the record memory address can be the actual physical address of the record where the memory bandwidth is equal to the largest size of any of the records stored. Where memory bandwidth is too small, the key memory address may be comprised of block-frame address, with a block-offset address being generated by separate circuitry (for example, a counter that would be included with the record memory 78) that strobes block-offset address lines to read out the record of data. On the other hand, the record memory 78 may be constructed as a virtual memory of some type, where the record memory address is mapped to the actual location. The mapping circuitry is included within record memory 78. A virtual memory implementation is generally not preferred, as this simply adds a second layer of mapping that slows access times. However, as the associative memory module 500 is designed to handle large numbers of keys, it may be desirable possibly to use it with some types of virtual memory. It should be further noted that the amount of memory space allocated for a record of data is usually fixed (though, if desired, it can be variable). If the record is too large, a pointer is stored in the record space pointing to the location of part or all of the actual record of data. No limitation is placed, as with like the index table memory 68, on the actual hardware configuration or hardware of the key record memory 78. Again, any media may be employed, preferably of a random access variety so that key records may be updated, added and deleted. However, some applications will need only ROM, which is generally faster. For reasons of speed, the type of memory should be chosen to have access times suitable to meet the particular application, subject to the limitations of space, cost, power consumption, heat dissipation, and durability. Where adding, deleting and updating records of data are desired, as with the communications system of FIGS. 1-4, several additional logic circuits are incorporated in the associative memory module 500. These logic circuits may be dedicated circuits or programmable devices which implement the logical functions of the circuits. The host system for the associative memory module may also augment or be used in place of some or all of these devices to handle some or all of the processing that is carried out by this circuitry. To update a record already stored by record memory 78, an “UPDATE” command on line 521 is presented to store record logic at the same time the record's associated key is placed on input key bus 501. Store record logic 94 then writes the updated record stored by the host system in key record buffer 525 into record memory 78 at the record memory address generated from the key. Adding records and their keys requires that its key be “learned”. The key for the record to be added is presented to the associative memory module on input lines 501; the record to be added is placed in key record buffer 523; and an “ADD RECORD” command is given on line 517. Each symbol of the key is processed as previously described. Frequently, at least one, and sometimes all but one, of the symbols in the key has already been encoded. If a symbol (as defined by its value and position within the key) has been encoded, learned key logic performs no function, and the key index values are read into arithmetic computation logic circuitry 72. However, when zero detect circuitry 90 reads a zero on line 505 from the key index memory 68, a zero detect signal is provided on line 92 to learned key logic 88, as well as to the host system as a “No Index” signal. This “no index” or zero detect signal means that the table entry—the symbol position and value—contains a zero. At this point, learned key logic circuitry 88 generates a new key index value and provides it to key index table 68 on write index bus 520. The index table memory then stores it in the entry of the key index table memory indicated by table address 503. As will be discussed in connection with the remaining Figures, learned key logic circuitry 88 requires, in order to generate the new index value for the key symbol, the key symbol value and position, and index values on read index line 505. Therefore, learned key logic is coupled to the key symbol buffer 104, the symbol position counter 106, and read index bus 505. Processing the key symbols presented on lines 501 then continues as before, with learned key logic generating new key indexes as necessary. When all of the symbols of the key have been processed, and their corresponding key index values added to a record index value 74 by the arithmetic computation circuitry 72, the record in buffer 523 is stored in the key record memory 78 at the location indicated by the record index. To delete records, the host system presents a “DELETE RECORD” command on line 519. To perform the delete function, the key must be presented on input key bus 501. Learned key logic 88 then deletes any key index value that is being used only by the key associated with that record by writing a zero into the table entry with write index bus 520. Deleting any unused index values permits them to be reused for the un-encoded key symbols that may be subsequently presented, thereby providing more efficient use of the record memory 78. The “deleted” record is simply overwritten with a new record when one is presented. Please note that where an ability to add, delete and update records is not desired, learned key logic circuitry is not necessary. All that is required is an encoded index table memory 68, arithmetic computation circuitry 72, key record memory 78 written with all of the records and suitable timing circuits and buffers. The index values that are stored in the index table memory 68 may be generated separately on a general purpose digital computer, from a known set of keys, and then stored in the memory. One of these methods for doing so has already been described in connection with FIGS. 2-4. Other methods will be described in connection with the remaining figures. If the index table memory is a ROM, for example, the index values are stored in the manner provided by the ROM device. Referring now to FIG. 6, learned key logic circuitry 88 includes three main components: add key logic circuitry 601; symbol use count logic circuitry 603 and delete key logic circuitry 605. The function of add key logic circuitry is to generate new keys that are provided to write index bus 520 for storing in the key index table memory 68 (FIG. 5). In one embodiment, add key logic recycles key symbols to key symbol buffer 104 with bus 609. Add key logic is coupled to symbol counter 106, key symbol buffer 104, read key index bus 505, zero detect line 92 and “ADD RECORD” command line 517 so that it receives the current key symbol position or count, key symbol value and key index in addition to the zero detect and add command. Add key logic provides an increment (INC) command on line 607 to symbol use count logic 603 for each key symbol presented on line 501 during an add key operation. Symbol use count logic 603 tracks for each key symbol value and position, or entry in the key index table memory 68, the number of different keys that share that particular symbol value and position. Symbol use count logic receives the symbol value and symbol position from key symbol buffer 104 and symbol counter 106, and the increment command signal from add key logic on line 607. A key index value for a particular symbol that is shared by more than one key cannot be deleted. If symbol use count logic circuitry indicates that a particular symbol has been encoded into the index table for only one key, then delete key logic circuitry 605 writes a zero to the write index bus 520. Referring now to FIG. 8, symbol use count logic circuit 603 tracks the number of times a particular symbol, Symbol[i] in a particular symbol position or bank i, is used by different keys. The key index value assigned to Symbol[i], INDEX[i,Symbol[i], can be deleted when it is no longer being used by any key. Essentially, it uses a symbol use count table memory 801 that is constructed and addressed like the key index table memory 68 (FIG. 5). As indicated by summer 802, values in symbol counter 106 and key symbol buffer 104 are used as bank and offset addresses, respectively, to a particular table entry for the key currently being processed. The data value stored in each entry is the number of keys that are currently encoded that share or use the value Symbol[i] in position 1. When the table memory 803 is addressed, the use count for Symbol[i] is read into counter 803. When a key is being added, the value in counter 803 is then incremented by one with an INC command signal on line 707 from add key logic circuit 601 (FIG. 7). In essence, this counts the number of times a particular symbol[i] has been presented to the associative memory as part of a key that is being added. When a record is being deleted, counter 803 is decremented by one with the delete record command on line 519. After expiration of a period of time allowed for the step of incrementing or decrementing, the value in the counter 803 is written back into the table memory 801 at the same table address. It is, further, read by zero detect circuit 805. If a zero count is detected during a delete record operation, a logic signal on line 807 goes high. This signal and the delete record command on line 509, also a logic high signal, are provided to AND gate 809, which is part of delete key logic circuit 605. Both signals going high causes a zero to be written on to write index bus 520 by circuit 811. Referring now to FIGS. 9 to 14, these figures disclose a third method (in addition to the two methods previously described in connection with FIGS. 2-4 and 7, respectively) of adding keys (the actual records may be stored later) using a different add key logic circuit. Basically, this method or process assigns key index values for key symbols when keys are presented in a monotonically sorted or lexigraphical order (either ascending or descending) for entry into the associative memory. The sorted order of the keys helps to eliminate “holes” for possible combinations of key symbols which are not presented in a sorted order or sequences, creating a near “perfect hashing” or “perfect packing”. Should a key be presented whose sum of key index values is the same as the sum of key index values for a previously entered key, current or previous key index value assignments are changes, and any previously stored key records are moved in memory to create a “hole” for the new key. The adding process is completed when the highest or last record memory location is filled. Referring now to FIG. 9 only, showing in schematic representation a dedicated circuit embodiment utilizing this method, add key logic circuitry 601 includes as major components: save table 901; change table 903; create index values logic circuit 905; change old value logic circuit 907; save new index logic circuit 909; and a directory table 911. The save table 901, change table 903 and directory table 909 are data structures stored in a random access memory. The logic circuits 905, 907 and 909 are shown to be dedicated circuits (possibly LSI or VLSI devices), but may implemented with programmed logic devices, general purpose computers, a microprocessor, or a combination of these performing the steps of the method. Both the save table and the change table have one row of values for each symbol position i in a key, i=1 to N, as shown by symbol position columns 913 in each table. Symbol counter 106 is therefore used to select a row in the save table, identified as Save[i], and in the change table, identified as Change[i]. Each table has three additional columns for storing values: associated with Save[i] and Change[i]. The save table keeps values of the symbols for the current key being added. In the save table 901, column 915 stores a value Save[i].symbol. This value is set equal to the symbol value, Symbol[i], from symbol buffer 104. Thus, Save[i].symbol=Symbol[i]. Column 917 receives from the key index table on read key index bus 505 an index value for Symbol[i], Index[i,Symbol[i]], and stores it. The column 919 receives the zero detect logic signal on line 92 and stores a value for a variable Save[i].new. This value is “new” (actually a data value arbitrarily chosen to represent “new”) when a zero detect signal is received, indicating that the value for Save[i].index is new and that Symbol[i] had not been previously encoded into the key index table memory. Thus, Save[i].new=new. Otherwise, a data value representing “old” is stored: Save[i].new=old. Symbol position counter 106 selects a row of the Save table corresponding to the key symbol position currently being processed. Selection enables the values in each column of the selected row to be accessed (read and written to) with bus 920. The change table 903 keeps information on the last index values assigned for each symbol position to allow “holes” to be made for new keys and to move any records if required. The change table 903 stores the previous symbol, record index and key index values for each symbol position [i] that are need to generate the next key index values for the next new key presented to the associative memory. Change table 903 therefore has three columns, one for the last assigned values of the following variables or data elements: for the record index value, Change[i].record; for the key index value, Change[i].index; and for the symbol value, Change[i].symbol. Like the Save table, the symbol position counter selects the row in the table, enabling entries on that row to be accessed (for reading and writing) by bus 922. A directory table 923 is also kept. A row of the table is selected with a data value generated by create index values logic 905 and save new index logic 909. This value is notated simply as “sum”, as it is a sum of all of the key index values for a key that is being processed. The number of rows in the table equals the number of record locations in record memory 78. The value “sum” is in fact equivalent to the record index value for the key being processed. Each row of the table has one entry, Change[sum].dir, for each record location in the record memory, sum=1 to P. This entry has one of two values; one representing the location is “assigned” and the other indicating the location is “unassigned”. This data structure may be set up in any memory element in the associative memory or host system. It can even be made part of the record memory 78 (FIG. 5). Coupled between buses 920 and 922 are create index logic 905, change old index logic 907 and save new index logic 909 which permit the logic elements to read and write values to the respective tables. Please note, however, the buses 920 and 922 are merely a functional representation, intended to simplify presentation. The actual data exchange structures between the different elements of add key logic 601 may differ substantially depending on the memory and logic elements selected to implement the data structures of the tables and the logic. For example, when implemented on a specially programmed general purpose digital computer, the data exchange structures will be those of the particular computer chosen. Save new index logic 909 is further coupled to the write key index table bus 520 so that new index values can be stored in the key index table memory 68, as well as to key symbol buffer for recycling key symbol values. Referring now to FIGS. 9 and 10, illustrated is a flow diagram describing the operation of create index value logic 905. Create index values logic 905 may be implemented with either dedicated circuitry or programmable logic circuitry, possibly shared with the other logic circuits in the associative memory module, or some combination of the two. In the latter case, the steps of the flow diagram would be implemented with programmed instructions. At start-up of the associative memory, as indicated by circle 1001, all logic components are reset at step 1003, and all tables initialized to zero (written with all zero values) at step 1005. Step 1005 includes setting Index[i,Symbol[i]] to zero, for all i and Symbol[i]. When the host system presents a new key for addition or encoding into key index table memory 68 (FIG. 5), it signals at step 1007 that a new key is being presented on key symbol bus 501 (FIG. 5) and the create new index value process begins. Step 1009, (FIG. 9) indicates when each symbol within the key is presented for processing as indicated by the symbol count being greater than zero. When a symbol is presented, the create new index value process continues to decision step 1011. If the new symbol is the first symbol of the key, then Sum is set equal to zero and i equals one. Further, a variable Any_New is set equal to “old”. Any_New is subsequently set to “new” if any Save[i].new=“new” from i=1 to N. In other words, “new” is entered in the new column 919 for any symbol position in the Save table; otherwise it is “old”. Any_New is a flag which indicates that one or more of the Save [i].new values is set to “new”. At decision block 1015, if the key being presented to the associative memory is to be added, as indicated by the Add command signal on line 517 (FIG. 6) being turned on, create index logic performs the steps outlined in block 1017. If the key is not being added, the created index value process ends. The process steps of block 1017 involve setting the Save table entry Save[i].symbol equal to the symbol value Symbol[i] from the key symbol buffer 104 (FIG. 6). Create index value logic next reads, as indicated by decision block 1019, the index value, Index[i.Symbol[i]], from the read index bus 505 (FIG. 5), and if it is equal to zero, proceeds to the process steps of block 1023. These steps include setting Save[i].index=Change[i].index+1; Any_New=“new”; and Save[i].new=“new”. Otherwise, the steps of block 1021 are undertaken: setting Save[i].index=Index[i,Symbol[i]]; and Save[i].new=“old”. After either the steps of block 1019 or block 1021 are performed, as the case may, the value assigned to the variable Sum is updated to Sum=Sum+Save[i].index at block 1025, and i is incremented by one, i=i+1. If i is less the N, the number of symbols in a key, then the steps indicated by blocks 1011 to 1025 are repeated. Once i=N, then create index value logic signals change old index logic 907 (FIG. 9) and passes the current value for Sum, as represented by blocks 1029 and 1031. The process of create index logic then ends until a new key is presented. Referring now to FIGS. 9 and 11, if the sum of the record index values is a record index value addressing a location in record memory 78 (FIG. 5) already having a key assigned to it, then this new key cannot be entered until either the previous key is moved to a new location or the new key's sum is increased until an unassigned location is found. Either of these moves are accomplished by increasing the value of an index value assigned to some previous key and also used by the new key being processed or increasing the value of an index newly assigned to this key. First, change old index logic 907 checks to see if the sum of the Index values for the new key, the sum of Index[i,Symbol[i]] from i=1 to N has been assigned. To do this, change old index value logic gets the value for Sum for create index logic 905 on bus 922. As indicated by decision block 1103, change old index value logic selects from the directory table 923 using the select line 925 the value for Directory[sum], which then reads this value out onto bus 922 for retrieval by change old index logic. If Directory[sum] equals “unassigned”, this indicates that the index values for the new key sum to a record index that has not previously been assigned to a key. Change old index logic then determines whether Any_New=“new”, as indicated by decision block 1105. If Any_New=“old”, the process ends. If Any_New=“new”, then save new key logic 909 is signalled to begin and the value for the variable Sum passed to it, as indicated by blocks 1107 and 1109, and the process carried out by change old index logic ends. If, on the other hand, Directory[sum] is assigned, the process of change old index logic continues at decision block 1111. If Any_New=“old”, a previously assigned index value must be increased to make a “hole” for the new key. The process proceeds to the steps shown in FIG. 12, which are discussed in connection with that figure. Otherwise, if Any_New=“new”, indicating that one of the index values for the current key was newly assigned or created by create index value, this new index value is incremented by one, thereby incrementing Sum until an “unassigned” location in the Directory table, Directory[sum]=“unassigned”, is found. An “unassigned” value indicates that the that a record memory location addressed by the a record index value equaling Sum has not been assigned to a key and is available for storing a record associated with the new key. The steps for increasing the newly assigned index value are carried out by a loop shown between blocks 1113 to 1121, the loop being repeated for each symbol position i from i=1 to N, as indicated by block 1113. First, the value of Save[i].new is tested for whether it is “new” or “old”, as shown by block 1115. If it is “old”, the process moves to the step of block 1117, where i is incremented by 1 or, if i=N, is set equal to 1, and the loop restarts by returning to block 1113. If Save[i].new=“new”, the process moves to steps shown by block 1119. There, Save[i].index and Sum are incremented by one, and i is also incremented by 1 unless i=N, then it is set equal to 1. The incremented Sum value must be tested to see if it has been assigned; as shown in block 1121, whether Directory[Sum]=“assigned”. If it has been “assigned”, the loop must continue at block 1113. If unassigned, the new index value is saved by signalling save new index value logic 909 and passing the Sum value on line 926, as indicated by blocks 1123 and 1125. Referring now to FIGS. 9 and 12, where Directory[Sum]=“assigned” and Any_New=“old” at steps 1103 and 1111 in FIG. 11, the processes of change old index logic 907 carry on by increasing a previously assigned index value in order to make a “hole” in the record memory for the record associated with the new key. Three additional variables are required to continue the change old index value process. Directory_Position is a pointer to the Directory table 923 that will point to the record memory location at which the hole is made. Symbol_Position keeps track of the symbol position of the index value which will be increased to make a hole. As indicated by block 1201, Directory_Position is initially set equal to Sum, and Symbol_Position is set equal to 0. Starting with block 1203, a loop begins that is designed to find an index value in the change table 903 that was previously assigned to one of the symbols of the key currently being processed. To do this, the loop begins at i=1 and compares Change[i].Symbol in the change table and Save[i].symbol in the save table to see if Change[i] Symbol Save[i].Symbol, as shown in block 1205. Where Change[i].Symbol=Save[i].Symbol, two other conditions are tested. First, Change[i].record, the record index value or Sum at the time the Symbol[i] was assigned, is compared against the current Sum, as shown in block 1207. Second, it is compared with Directory_Position, as shown by block 1209. If Change[i].Symbol is greater than both, then: in block 1211, Symbol_Position is set equal to i and Directory_Position is set equal to Change[i].Record; and, in block 1213 and decision block 1215, i is incremented by one and the loop repeated until i=N. Otherwise, the steps of block 1211 are not performed and the loop repeated for i=i+1 until i=N. In effect, this loop is not only trying to find an index value in the save table having a symbol shared by the current or new key, it also finds, where there is more than one such symbol, the index value that, when assigned, had the largest record index value. The Directory_Position variable keeps track of the largest record index value found as the loop is performed. At the termination of this loop, change old index logic tests, at decision block 1217, whether the final value for Directory_Position is greater than Sum. If not, then this new key was not in a sorted order with respect to previously presented keys and an error message is flashed to the host system, as indicated by block 1219. Otherwise, it continues to another loop, starting with by block 1220. Before beginning this loop, a variable Increase is set equal to 1, as shown in block 1222. The value of increase is the number by which the records in the record memory must be moved to create the “hole”. The first step in the loop is to increase Sum by one, as shown in block 1221. Next, at block 1223, Sum is compared against Directory_Position. If it is less than Directory_Position, Directory[Sum] is looked up in the Directory table 923 to see if that record index has been assigned, as indicated by decision block 1225. If it is assigned, one is added to the value of Increase, as shown in block 1227. The loop repeated until Sum is either equal to Directory_Position or Directory[Sum] is “unassigned”. Referring now to FIG. 13, once the processes of FIG. 12 are complete, change old index logic then signals store record logic 94 (FIG. 5), as indicated by block 1301, and passes to stored record logic the values for Directory_Position, Increase and Last_Assigned (a value is assigned to this variable by save new index logic as shown in FIG. 14). Store index logic utilizes these values to move a block of records within the record memory 78 (FIG. 5) addressed by record index values between Directory_Position and Last_Assigned to new a new block of locations addressed by record index values from Directory_Position+Increase to Last_Assign+Increase, thereby making the “hole” in the record memory for storing the record associated with the new key. Change old index value logic then updates the Save table and the Last_Assigned variable. “ii” is set equal to Symbol_Position, and Save[i].Index=Change[i].Index+Increase, Save[i].New=“new”, and Last_Assigned=Last_Assigned+Increase, all as shown in block 1303. Then, as indicated by blocks 1305, 1307, and 1309, a loop is performed for each i beginning with i=Symbol_Position+1 and continuing to i>N to update the Change table to reflect the movement of the records in the record memory by store record logic, particularly Change[i].Record. To do this, the loop tests Change[i].Record, as shown in block 1311, to see if it is greater or equal to Directory_Position. If so, the step of block 1313 is performed, setting Change[i].Record=Change[i].Record+Increase. After completion of the loop at block 1309, change old index value logic signals save new index value logic on line 926 and passes Sum, as shown by blocks 1315 and 1317. Referring now to FIGS. 9 and 14, processes of save new index logic 909 begin with block 1401, in which i=1 and Symbol_Count=0. The remaining process steps are part of a loop that is set up by steps shown in blocks 1403, 1405 and 1407 and repeated for each i, from i=1 to N. The loop therefore essentially sequences through each symbol position in the Save table 901. For each symbol position, it reads the symbol value, Save[i].Symbol, from the Save table and writes it to symbol buffer 104 using bus 929, as described in block 1409. Writing the symbol value to the symbol buffer 104 also strobes the symbol counter 104, as indicated by line 931. After a delay, indicated by block 1411, the value in symbol buffer 104 is tested against the value of Save[i].Symbol to ensure that the value of Save[i].Symbol has been placed in the symbol buffer, as shown in block 1413. If, as indicated by decision block 1415, the symbol position i has a new index value, Save[i].new=“new”, then the new index value is stored in the index memory 68 (FIG. 5) by simply writing it write index bus 520 (the symbol counter and symbol buffer already are set to select the correct symbol position and value entry). The new index value is also stored in the Change table 903. Save new index logic further stores the symbol value and Sum, the sum of the index values, in the change table. These steps are shown in block 1417, and described as: Index[i,Symbol[i]]=Save[i].Index; Change[i]Record=Sum; Change[i].Index=Save[i].Index; and Change[i].Symbol=Save[i].Symbol. The variable Last_Assign is also set equal to Sum, as indicated in block 1419, but only if Sum is greater than Last_Assign. Otherwise, it remains unchanged. If Save[i].new=“old”, then the steps of block 1417 are not performed, as there are no new index values that need to be updated. As shown in step 1421, only Change[i].Record needs to be updated by setting it equal to Sum, but only if Change[i].Symbol=Save[i].Symbol and Change[i].Record>Sum. When i>N, the processes of save new index logic 909 exit the loop and signal the host system that the new key has been added, as indicated by block 1423. The value of variable Last_Assigned is passed to change old index logic 907 on line 927, as indicated by block 1425. This then completes the processes for adding a key according to a third method for keys presented in sorted order to the associative memory module 500 for adding. Further keys are added in the same manner. Referring now to FIGS. 3, 8 and 15, there is illustrated the hardware and a flow diagram required for the assigning of index values to an entire key-set group using an alternative method for assigning index values. The use-count table (801 of FIG. 8) is updated as a set of keys are presented to the system. Before the process of updating the use-count table begins, all positions within the use-count table are reset to zero or a null value at step 1500. The first key is then presented at step 1502 to the system logic and the first symbol of the key is read at step 1504. At step 1506, the USE COUNT for the symbol value in the present symbol position is incremented by one to indicate a use of the symbol value. Next, a determination is made at step 1508 as to whether the final symbol has been presented for a key. If the last symbol has not been presented, control passes to step 1504 and the next symbol is read. If the last symbol for the key has been presented, step 1510 determines if another key is to be presented to the control logic. If another key is to be presented, control passes back to step 1502. Otherwise, control will pass to step 1512. At step 1512, the BASE value for the least significant symbol position is set equal to one. For each subsequent symbol position or bank, the base value will equal the maximum index value for the previous symbol position. The CURRENT COUNT for the symbol position is then set equal to one at step 1514. The control logic scans at step 1516 the least significant bank values of the use count table. The first symbol value entry for the bank is read at step 1517. A determination is made at step 1518 if the initial use count table entry is greater than zero. If the entry is not greater than zero control passes back to step 1517 and the next symbol position for the present bank in the use-count table is read. If the value is greater than zero, an index value is assigned to the symbol at step 1520 and placed in the corresponding bank and position in the index table 98 of FIG. 3. An inquiry at step 1540 determines if another symbol value exists for the present symbol position. If so, the CURRENT COUNT is incremented by one at step 1542 and control returns to step 1517. When no further symbol values exists in the current bank, the control logic looks for the next bank at step 1546. If another bank exists, the BASE value is set equal to the present BASE value times current count at step 1548 and control returns to step 1514. Otherwise, all index values for the keys have been assigned and the process is complete. Referring now to FIGS. 8, 16, and 18 another process is illustrated for assigning index values to symbols for an entire key set. Initially all index-value tables and use-count values are reset to zero or a null value at step 1600. This includes initializing values in the maximum suffix table 1910 to the minimum suffix symbol string and initializing the minimum suffix table 1920 values to the maximum suffix string. Next, a key is presented at step 1602 to the control logic and the first symbol of the key is read at step 1604. The use count for the read symbol value at the present symbol position is incremented at step 1606 to indicate a use of the symbol value at the symbol position. An inquiry is made at step 1608 to determine if the suffix of the present symbol is greater in the collating order than the stored MAX SUFFIX. The suffix of a symbol in a key is the key ordered sequence of all the symbols of lower collating value than the current symbol. For example, the suffix of 3 in the key 12345 is 45 and the suffix of B in key ABCDE is CDE. The suffix relative size determination is based on the collating order of symbol in the suffix and not the index value. If the current suffix exceeds the previously stored MAX SUFFIX in collating order, the MAX SUFFIX is set equal to the present suffix at step 1610 and stored in the max suffix table 1910 (FIG. 19). Should the suffix be less than MAX SUFFIX in collating order or after MAX SUFFIX is set equal to the present suffix, control passes to step 1612 where an inquiry is made to determine if the present suffix is less than the previously stored MIN SUFFIX symbol string. If so, at step 1614 the MIN SUFFIX is set equal to the present suffix symbol string and stored in the min suffix table 1920 (FIG. 19). Otherwise, step 1616 determines if another symbol value exists within the present key. If another symbol exists, the next symbol is presented to the control logic at step 1604; if not, step 1618 determines if another key must be presented to the control logic. Additional keys return control to step 1602. Once all keys have been presented to the use count table 801 of 8 and 18, max suffix table 1910 of FIG. 19, and min suffix table 1920 of FIG. 18, control passes to step 1620 to begin the process of assigning index values to the key symbols. The use count table 801 of FIG. 8 and FIG. 19 stores integer count values. The max 1910 and min 1920 suffix table memories store symbol sequences. At step 1620, the base value for the least significant symbol position is set equal to one and the value for LAST NON-ZERO ENTRY is set equal to zero. Next at step 1622, the value for CURRENT COUNT is set equal to one. The least significant bank in the use-count table is scanned at step 1624. The initial symbol value in the bank is read at step 1626 and an inquiry is made at step 1628 to determine if the first symbol value use-count number is greater than zero. If not, control returns to step 1626 and the next symbol value in the bank is scanned. Otherwise, an inquiry is made at step 1630 to determine if the LAST NON-ZERO ENTRY value is greater than zero. If not, the symbol value is assigned an index value of one at step 1632, LAST MAX SUFFIX is set at step 1633 equal to a null string, the CURRENT COUNT is incremented at step 1634 and the LAST NON-ZERO ENTRY value is set equal to one at step 1636. Control then passes back to step 1626 and the USE COUNT value of the next symbol value in the use-count table is read. If inquiry step 1630 determines the last non-zero value is greater than zero, the symbol position is assigned at step 1632 an index value according to the following equation: Index value=last non-zero index value+max suffix index value for the last non-zero index value−min suffix index value for the present symbol value. The max suffix and min suffix index values are equal to the sum of the index values of the key symbols comprising the suffix. The CURRENT COUNT is incremented and the LAST NON-ZERO ENTRY value is set equal to the present index value at step 1634. At 1643, the last max-suffix value is set equal to the max-suffix value for the current position. The max and min suffix values for the least significant symbol position or bank are both zero. Inquiry step 1636 determines if the last symbol value for the bank has been scanned. If not, control returns to step 1626 and the next symbol value is read. If the last symbol value has been read, step 1638 determines if another symbol position exists in the use-count table and if so returns control to step 1622; otherwise, the procedure is completed and all the symbol values have been assigned an index value. Referring now to FIGS. 8, 17 and 20 there is described a method for incrementally updating the index tables and directory table of the present invention. This dynamic directory sizing process allows the number of non-zero entries in the index value tables to expand and contract as new keys are added or deleted and to minimize the size of the directory. This method expands the ADD KEY and DELETE KEY logic (601 and 605 of 88 in FIG. 6) processes earlier described. The USE-COUNT logic (603 in FIGS. 6 and 8) remains the same. As before, the ADD-KEY logic will only operate when the ZERO DETECT (92 of FIG. 6) indicates that a symbol value location in a bank of the index value table has no index value assigned or the compare keys (2009 of FIG. 20) indicates a key mismatch. When the ZERO DETECT or key mismatch is indicated, the ADD KEY logic 601 activates the ADD-NEW-SYMBOL process. The ADD-NEW-SYMBOL process produces a non-zero index value for a symbol value which previously had a zero or null index value or in which the count flag was zero. In addition, the ADD-NEW-SYMBOL process increases the higher order index values above the new index value. The ADD-NEW-SYMBOL process operates as illustrated in FIG. 17. First, several parameters are initialized at step 1700 to track the symbol positions within the index value table and directory table. The size of the spaces to be left to accommodate the new symbol value is calculated and set equal to NEW SIZE. NEW SIZE equals the base value of the bank where the partition point will occur. The size of the directory block to be moved, BLOCK SIZE, is set equal to the maximum index value in the bank were the partition point will occur before the index values are changed. The number of BLOCK SIZE directory blocks to be moved is calculated by dividing the size of the old directory by BLOCK SIZE. This value is set equal to NUMBER OF BLOCKS. Next, the partition point within the bank where the new symbol value will be added is determined at step 1702. When count flags are used, the compare keys logic 2009 of FIG. 20 compares the new key with the stored key and provides the learned key logic 88 with the symbol positions and symbol values that are different between the two keys. One of the symbol positions is selected and the symbol value having a count flag equal to zero has its count flag set to one. At least one of the two symbol values must have its count flag set to zero or the symbols would not have the same index value. The partition point is the point at which any pre-existing index values will be lower in symbol value than the new symbol to be added. The partition point is determined by counting the number the of non zero count flags or non-zero index values from the beginning of a bank to the new symbol value including the new symbol value. When non-zero index values are counted, this count value is multiplied by the base of the present bank. The product is the index value for the new symbol. When count flags are used, the index value is already assigned to the partition point location in the index table. The new index value(s) within a bank is assigned at step 1704 by increasing each non-zero index value located higher in the bank by the base value for the bank. The symbol value of the partition point is saved in a register PARTITION SYMBOL and the index value for the partition point is saved in PARTITION INDEX. At step 1706 new base values for banks above the partition point in the collating sequence are computed based upon the added symbol value where a present base value equals the previous base value times the number of non-zero index values in the present bank. Then the size of the new directory is computed at step 1707 as the new base value for the most significant symbol position times the number of non-zero index values in that bank or symbol position. This is the same as the largest new index value in that bank. Next, memory space is appended to the top of the old directory at step 1708 to accommodate the new symbol value within the new directory. The amount of memory appended equals the new directory size minus the old directory size. First, the block between the top of the old directory and the index value of the next non-zero count flag above the partition point are moved at step 1709 from the old directory location to the end of the new directory location. The size of the first block equals the number of non-zero count flags or index values above the partition point to the end of the bank multiplied by the base value for the bank. The result is saved as ABOVE COUNT. At step 1710, the key values in each of the NEW SIZE locations just below the block in the old directory moved at either step 1709 or 1712 are examined to determine if the symbol value at the partition point is greater than the PARTITION SYMBOL value. If the stored key symbol has a symbol value greater than PARTITION SYMBOL, the record associated with the key symbol is moved up from its current location in the old directory to the corresponding point in the NEW SIZE hole below the block just moved at either step 1709 or 1712. If the symbol value is equal to or less than PARTITION SYMBOL the record is left in its present position in the old directory. This process creates a hole below the previously moved block with selected records moved into the hole in the new directory table at step 1710. The hole size is equal to NEW SIZE. This hole accommodates entries using the new symbol value, including those which already used that value if count flags are used. At the end of the hole, another block of directory locations are added to the new directory at step 1712. The size of this block equals BLOCK SIZE. This next block to be moved starts at the next location below the last location of the previous block moved from the old directory to the new directory by either step 1709 or 1712. The elements of each block moved are selected in descending order between: partition points in the old directory. An inquiry step 1714 determines if the final old directory block has been reached. The final block is already stored at the correct location in the new directory if the same memory location is used for both the new and old directory. If not the final block, the next new index value space of block size is skipped at step 1710. The size of the final directory block equals BLOCK SIZE minus the size of the first block. This process of moving directory records from the old directory to the new directory allows the new directory to be built on top of the old directory location. Finally, at step 1718 the new index values for the symbol positions in the banks following the partition point are calculated using the new base values. The new index values are assigned by assigning the base value to each location in the bank from the first location up to and including the first location having a non-zero count flag or a non-zero index value. After each non-zero count flag or non-zero index value location, the index value assigned is increased by adding one more base value to the previous value until all previous non-zero index value or non-zero count flag entries in the bank have been assigned. When a key symbol is removed from the index table, the REMOVE KEY LOGIC executes a compact process. The compact process is the reverse of the expand process and removes the index value of the symbol from its bank of the index value table and adjusts the value of the remaining symbol value indexes to compact the directory to a minimal size. Referring now to FIG. 18, once a use of a symbol value discontinues at step 1800, the use count for that symbol value is decremented by one at step 1802. A determination is then made at step 1804 to determine if the use count for the symbol value equals zero. If not, the process stops and no further action is taken. Should the use count equal zero, then all the other use counts using this index value must also be zero, before the index value may be removed. In other words, all symbol values with the same index values must all have zero use counts before the REMOVE KEY LOGIC begins a compact process to decrease the size of the directory table and reassign index values in the index-value table. First, tracking parameters are set at step 1806. These parameters include determining NEW SIZE, BLOCK SIZE, and NUMBER OF BLOCKS. These values are calculated is the same manner as described earlier for the ADD NEW SYMBOL process. The partition point of the bank where the symbol is to be removed is set equal to the index value of the removed symbol at step 1807 and the index values within the bank are reset by subtracting the base value from every non-zero index larger than the partition point in the bank at step 1808. Next, the new base values for the index value table are computed at step 1810. Then the size of the new directory NEW MAX is computed at 1812. NEW MAX equals the base value of the most significant symbol, position times the number of non-zero index values or valid flags plus one in that bank. The STORED RECORD LOGIC 94 moves the old directory to its new location. The MOVE directory process iterates over the old directory starting at the bottom and going up until all blocks have been processed. Initially the data between the beginning of the directory and the partition point is already the beginning of the new directory. Next, at step 1816 a group of data corresponding to directory locations utilizing the removed index value are skipped or removed from the directory. This group of removed data blocks is equal to the value of NEW SIZE. Next, a block of data directly after the removed block and equal to BLOCK SIZE is moved down to fill in the removed block of data at step 1818. If inquiry step 1820 determines the last block has not been reached, control passes to step 1816 where a block of data is skipped in the old directory corresponding to NEW SIZE and a BLOCK SIZE number of entries are moved down to fill the removed data. Finally, the last block of data having a size corresponding to the value of BLOCK SIZE minus the length of the block of data between the beginning of the directory and the original partition point is moved below the final block at step 1822. After the new directory has been created, new index values are assigned at step 1824 in the index value table and are calculated using the new base values and current count for the bank as described earlier. The new index values may be calculated at any point after the NEW BASE values are calculated 1810. Once the new index values are assigned, the compact processing is complete. Referring now to FIGS. 20 to 22, there is illustrated yet another embodiment of the invention. The embodiments in FIGS. 20 to 22 are slightly altered from the apparatus disclosed in FIGS. 5, 6 and 8 and enables index values to be assigned to valid and invalid key symbol locations within the INDEX VALUE TABLE 68. This allows an index value to be calculated for record keys containing invalid key symbols. The calculated index value will point to a location in the neighborhood of index values for record data with similar key values. Referring now to FIG. 20, this figure illustrates the generic associative memory of FIG. 5, shown with the addition of count flag logic 2000 and in-use logic 2002, flag count logic 2003 and compare keys logic 2009. Other than the above mentioned components, the circuitry and logic are the same as described with respect to FIG. 5 and similar reference numbers have been used. The count flag logic 2000 counts the number of invalid key symbols in a key symbol string. An invalid key symbol is one whose corresponding valid symbol flag bit in the INDEX TABLE of FIG. 5 is zero. In the method of FIG. 20, all index table entries are non-zero (zero value entries may also be used) and each index table entry includes a valid symbol flag bit to indicate whether a symbol value is valid or invalid. The count flag logic 2000 determines the number of invalid symbols by checking the valid symbol flag bit for a symbol position in the INDEX VALUE TABLE 68 for each symbol presented. Each integer value in the INDEX VALUE TABLE 68 has an additional flag bit which is set to one (1), if the index value stored at that location is different from the next higher location in that bank. This occurs when the table location (i.e., the BANK and symbol value) was used to compute the index value stored at this location. The flag is set to zero (0) if the table location is not used to determine a record index value stored at this location. Index values stored at these zero flag locations are duplicate of the higher adjacent location. The memory in-use logic 2002 checks a memory in-use flag bit within the key record memory 78 to determine if record data is stored in the location pointed to by a record index 74 value. The bit is set to one (1) if data is currently stored at a location and zero (0) if no data is currently stored at the location. The flag count logic 2003 is the value from the count flag logic 2000 generated when the record index 74 is computed. In addition, the input key 501 being presented to the associative memory must be compared in compare keys logic 2009 to the sequence stored in the key record to determine if the keys are identical. If the input key 501 and the stored key 2010 are not identical, the learn key logic 88 is notified by the keys not equal flag line 2011. Referring now to FIG. 21, this figure illustrates the learned key logic circuitry 88 from FIG. 20. The learned key logic 88 functions in a similar manner as that discussed in FIG. 6. Where appropriate, the reference numbers in FIGS. 6 and 21 are the same. The circuitry is similar to that of FIG. 6 with the following exceptions. The add key logic 601 no longer is connected to a zero detect line but instead receives input over the count flag line 2100. The count flag line indicates when an invalid input key symbol has been detected. Also connected to the add key logic 601 is the flags count line 2102 which inputs to the add key logic 68 the number of invalid symbols contained within a key record stored in record memory 78. The in-use flag line 2104 provides the add key logic 68 with an indication of whether a key record memory 78 location presently contains record data. The keys not equal flag line 2011 provides the add key logic 68 with an indication of whether the stored key (if there is a stored record) and the input key match. The delete key logic 605 receives commands over the compress logic line 2106 and the delete record line 519. Referring now to FIG. 22, there is shown the symbol use-count logic 603 and delete key logic 605. The circuitry shown in FIG. 22 is similar to that of FIG. 8. Where applicable the previous description and reference numbers remain the same. The circuitry functions in a similar fashion with the following exceptions. The compress line 2106, as described in FIG. 21, enters the delete key logic 605 and connects to AND gate 809. The compress signal command and a logical signal from the zero detect circuitry 805 are applied to AND gate 809. Both signals being true causes the execute compress logic 2107 to compress record data to fill in locations vacated by removed data. Referring now to FIGS. 23a and 23b, there is illustrated a flow diagram describing the method for assigning index values to an initial or entire key-set group including valid and invalid symbol values using an alternative method for assigning index values. The USE-COUNT TABLE (801 of FIGS. 8 and 22) is updated as a set of keys are presented to the circuitry. Before the process of updating the USE-COUNT TABLE 801 begins, all positions within the USE-COUNT TABLE are reset to zero or a null value at step 2300. The first key (for instance a text string or DNA sequence) is then presented at step 2302 to the system logic and the first symbol of the key is read at step 2304. At step 2306, the USE-COUNT for the symbol value in the present symbol position is incremented by one and the index table count flags set to one to indicate a use, of the symbol value at, the present symbol position. Next, a determination is made at step 2308 as to whether the final symbol has been presented for a key. If the last symbol has not been presented, control passes to step 2304 and the next symbol is read. If the last symbol for the key has been presented, step 2310 determines if another key is to be presented to the control logic. If another key is to be presented, control passes back to step 2302. At step 2303, the build index logic 2305 initiates the building of the INDEX VALUE TABLE. At step 2312, the BASE value for the least significant symbol position is set equal to one. For each subsequent symbol position or BANK, the base value will equal the maximum index value for the previous symbol position. The CURRENT COUNT for the symbol position is then set equal to one at step 2314. The control logic initially scans at step 2316 the least significant BANK values of the USE-COUNT TABLE. The first symbol value entry for the BANK is read at step 2317. An index value is assigned to the symbol position in the INDEX VALUE TABLE at step 2320 by multiplying the CURRENT COUNT by the BASE VALUE and the result is placed in the corresponding BANK and position in the INDEX VALUE TABLE 68 of FIG. 20. Inquiry step 2340 determines if another symbol value exists for the current symbol BANK. If so, a determination is made at step 2318 if the SYMBOL VALID FLAG entry equals zero. If the entry equals zero, control passes back to step 2317 and the next symbol position for the present BANK in the USE-COUNT TABLE is read and assigned an index value which is the same as the previously assigned index value. If the count flag equals one, CURRENT COUNT is incremented by one at step 2342 and control returns to step 2317. When no further symbol values exists in the current BANK, the control logic determines if another BANK exist at step 2346. If another BANK exists, the BASE value is set equal to the present BASE value times current count at step 2348 and control returns to step 2314. Otherwise, all index values for the keys have been assigned and the process is complete. Once completed, each symbol position within the INDEX VALUE TABLE 68 is assigned an index value, including invalid symbol positions not used by the presently stored symbol key set. With all the index table locations assigned a value, one can rapidly determine the “closeness” of an input key string sequence containing invalid symbols to key sequences already encoded into the USE-COUNT TABLE. Once the initial INDEX VALUE TABLE 68 values have been assigned using the process of FIGS. 23a thru 23c, additional keys may be added to associative memory. If the sum of the symbol index values identifies a location in RECORD MEMORY 78 where the IN-USE flag is not set (location not currently used) then the IN-USE flag is set and the record and key are stored with no modification to any index values in the INDEX VALUE TABLE 68. The USE-COUNT TABLE is updated with counts for all the new key symbols. If RECORD MEMORY 78 location for the new key (i.e., the sum of the symbol index values) is IN-USE (IN-USE set) and the keys are different then the values in the INDEX VALUE TABLE 68 must be modified to make room for the new key using the method described in FIG. 17. When a key is entered for which the sum of the symbol index values equals a record location which is already in use, and the key already stored in the location is different from the new key, the values in the INDEX VALUE TABLE 68 must be expanded to make room for the new key (or one of the keys must be discarded). The new key and the stored key are compared in the compare keys logic 2009. The compare keys logic 2009 informs the learned key logic 88 of the symbol positions and symbol values that differentiate the two keys. Symbol positions with different symbol values must be assigned the same index value or the two keys would not have the same index sum. To distinguish the two keys, one of the different symbol values must be assigned a different index value. The process defined in FIG. 17 describes the method for assigning one symbol a new-index value and relocating all the effected key records. In yet another embodiment of the invention, the USE-COUNT TABLES for various key sets may be applied to an associative set processor to obtain information regarding maximum key set sizes resulting from set operations union or intersection of one or more key sets. Referring now to FIG. 24, there is shown a block diagram for an associative set processor 2400 and its included circuitry. Two separate memory locations contain the set A symbol USE-COUNT TABLE 2402 and the set B symbol USE-COUNT TABLE 2404. It is to be understood that while the following description of operations relates to the use of two USE-COUNT TABLES, the operations are not limited to the union or intersection of two USE-COUNT TABLES. Both of these memory locations are connected to the associative set processor 2400. The associative set processor 2400 is capable of performing a number of set operations. These operations include a union function 2406 for creating a table of all elements existing within the two USE-COUNT TABLES (2402 and 2404), an intersect function 2408 for creating a table containing all common elements between the two USE-COUNT TABLES and a mask function 2410 for combining a mask table, where some or all of the entries equals one (1), with a symbol USE-COUNT TABLE to create an output table, wherein each USE-COUNT position, having a value greater than zero (0) and the corresponding location in the mask table is equal to one (1), then the resulting table location is set to the USE-COUNT. The associative set processor 2400 outputs to a result table location 2412. A table access counter 2414 allows the associative set processor 2400 to sequentially read through all the locations of the two input tables 2402 and 2404 and place the results of the set operation in the corresponding location of the result table 2412. The table access counter includes the BANK and COUNT of FIG. 25. At the end of an operation on two input tables, set A and set B, the maximum set size 2415 has been computed for the resulting set C which is the largest number of records in the set resulting from the same union, interest or mask operation being performed on the two key sets represented by table A 2402 and table B 2404. Referring now to FIG. 25, there is shown a flow diagram illustrating the method for carrying out the union function 2406. Initially, several counters are set at step 2500. COUNT and BANK, the table access counter 2314, are both set equal to one (1) and SUM is set equal to zero (0). MAX is set equal to the largest integer count. At step 2502, the maximum value of the first COUNT and first BANK position between the first USE-COUNT TABLE and second USE-COUNT TABLE is determined and stored at RESULT. RESULT is added to SUM at step 2504. Then RESULT is stored in the corresponding location of table 2412. Next, COUNT is incremented by one (1) at step 2506, and inquiry step 2508 determines if the value of COUNT has exceeded the size of the largest bank position. If the value of COUNT is less than the size of the bank position control passes back to step 2502 to determine the maximum value of the next position within the bank of the USE-COUNT TABLES A 2402 and B 2404. The RESULT is stored in TABLE C 2412. Once the maximum value of all symbol positions within a bank have been determined by (COUNT>BANK size) at 2508, control passes to step 2510 where COUNT is set equal to one (1). If SUM is less than MAX the value of the MAX is set equal to SUM. SUM is then set equal to zero (0), and BANK is incremented by one (1). Inquiry step 2512 determines if another bank exists, and proceeds to step 2502 to determine the maximum values within the next bank. If other banks do not exist, the value of MAX is output at step 2514 into maximum set size 2415 (FIG. 24). The value of MAX stored in maximum set size 2415 (FIG. 24) represents the maximum number of RECORD MEMORY 78 entries that could result from a union of the key sets of the RECORD MEMORIES corresponding to USE-COUNT TABLES A and B. That is a union of the keys of RECORD MEMORIES A and B can result in a RECORD MEMORY C with no more than MAX key records. Referring now to FIG. 26, there is illustrated a flow diagram of the operation of the intersect function 2408. Counters are initialized at step 2600. These counters include COUNT and BANK, which are set equal to one (1), and the SUM counter, which is set equal to zero (0). MAX is set to the largest count value. The initial value of RESULT is determined by finding the minimum value in the first BANK, first COUNT position of the A and B USE-COUNT TABLES (2402, 2404) at step 2602. RESULT is added to the value of SUM at step 2604 and the value of RESULT is output to the RESULT TABLE 2412. Next, COUNT is incremented by one (1) at step 2506 and inquiry step 2608 determines if the COUNT is greater than the size of the present bank. If count is less than the present bank size, control returns to step 2602. Otherwise at step 2610, COUNT is reset to one (1), the BANK value is incremented by one (1) and the value of MAX is set equal to SUM if SUM is less than MAX. SUM is then reset to zero (0). Inquiry step 2612 determines if another bank exists within the USE-COUNT TABLES. If additional banks exists control returns to step 2602. If all banks have been reviewed by the intersect function, the value of MAX is output to maximum set size 2415 (FIG. 24) at step 2514 by the associative processor. MAX represents the maximum number of key records contained in the record memory C from an intersect of the keys of record memories A and B. Referring now to FIG. 27, there is shown the method for performing the mask function of the associative set processor 2400. The mask table may be either table A or B. Counters are initialized at step 2700, wherein COUNT and BANK are set equal to one (1) and SUM is set equal to zero (0). MAX is set to the largest count value. Decision step 2702 determines if the value in the symbol position presently pointed to by the COUNT and BANK counters in USE-COUNT TABLES A and B, are both greater than zero (0). If so, then RESULT is set equal to the maximum value at this symbol position in either USE-COUNT TABLE A or B. If the symbol position in USE-COUNT TABLES A and B are not both greater than zero (0), RESULT is set equal to zero (0) SUM is then set at step 2704 equal to the value of SUM plus RESULT and the value of RESULT is output to the RESULT TABLE 2412. COUNT is incremented at step 2706 and inquiry step 2708 determines if COUNT is greater than the size of the present bank. If COUNT is less than or equal to BANK SIZE then all symbol positions within a bank have not been examined and control returns to step 2702. If all symbol positions have been examined, control passes to step 2710, COUNT is reset to one (1) and BANK is incremented by one (1). Also at step 2710, if SUM is less than the value of MAX, MAX is set equal to SUM then SUM is set equal to zero (0). Inquiry step 2712 determines if another bank exists to be examined. If another bank exists control passes to step 2702. If no other banks are present, the value of MAX is output at step 2714 to indicate the maximum number of key records that can be in the key record memory resulting from the mask operation. Referring now to FIG. 28, a series of USE-COUNT or INDEX tables 2800(a) through 2800(k) may be combined by a series of set operations into a result table 2802. This sequence of set operations is performed on like tables (either USE-COUNT or INDEX) using the associative set processor 2400. Initially, the RESULT table 2802 has all its entries set to the counts in the first table 2800(a). The table select switch 2810 selects the next table 2800(b) and the set operation is performed with set A stored in the result table 2802. Result table 2802 holds the USE-COUNT results of the operation between the first two record memories tables, for example the results of A intersect B. The input table selector switch 2810 is then set to the third USE-COUNT Table C 2800(c) and the set operation with the result table 2802.1s preformed, for example R union C. is (A intersection B) union C. The input and output table selection switches (2810 and 2812) are controlled by the associative set processor 2400 and sequence through all the USE-COUNT tables for all the record memory to be combined according to a user specified sequence of operations to perform the required set operations on each input USE-COUNT table. The result of each set operation includes a MAX value 2806 which is the maximum number of key records which meet the combined set operations. If during the processing, no union operations are left to be performed and the MAX value is zero (0), then there are no records in the resulting set, all the values in one bank of the result table 2802 are zero (0), and processing may stop with a null result. If after processing all the input tables, MAX is greater than zero (0), then the result table 2802 stores the resulting USE-COUNT table. This resulting USE-COUNT table may be used to filter all the original record memories to produce the record memory data set resulting from the sequence of operations. The resulting record memory can have no more than the final MAX records. To filter the original record memory data sets, the following operations are executed. First the result table 2802 containing the resulting USE-COUNTS for the sequence of set operations is intersected using the associative set processor 2400 with a unit table 2812 containing all one counts in every location. This intersection operation produces a results MASK table where every entry is either zero (0) if the result count was zero (0), or one (1) if the result count was greater than zero (0). Using the associative set processor 2400, a MASK operation as illustrated in FIG. 27 is performed with each of the initial input index tables 2800(a), 2800(b) . . . 2800(k) to produce result index tables 2802(a), 2802(b) . . . 2802(k) for the original record memory data sets. If the MAX value is zero (0), then the results set has no records. Referring now to FIG. 29, the results table 2802 in FIG. 28 containing the USE-COUNTS resulting from a sequence of set operations is used to generate an result index table 2900 using one of the index table creation processes previously described in FIGS. 5 to 23. Wherein similar functional elements to those previously described in FIGS. 5 to 23 are used, the same reference numerals have been utilized and the previous drawings and related description may be referred to for a more detailed disclosure of the functional element. By cycling through only the combinations of index values greater than zero (0) in each input index result table 2802, only the records belonging to the resulting set are selected from the record memory for each original set. The table selector switch 2902 and the record memory selector switch 2904 provide access to a result index table 2802(n) and its associated record memory 2906(n). For each resulting index table 2802(A), 2802(B) . . . 2802(K) the record memory 2906(A), 2906(B) . . . 2906(K) is accessed for each combination of non-zero index values. For each such record memory location which has a record stored indicated by INUSE flag bit 2002, that record is placed in the results record memory 2908. The location in the results record memory 2908 is computed using the sum of index values from the new result index table 2900. FIG. 30, is a flow chart of the symbol sequence scanner logic 2910 of FIG. 29. The scanner sequences through the all input result index table 2802(A) . . . 2802(K) at step 3000 and selects one at a time. At steps 3002 through 3010 the scanner generates all the non-zero input record indexes for the table. These are the records which could possibly meet the results set of a sequence of set operations between this set and all of other sets. First, the highest order bank or symbol position is scanned for a non-zero index value or count flag at step 3004. For each non-zero value found in the highest order bank, all the lower order bank values are scanned at step 3006 through 3010 and each non-zero index value is used to compute a record index. A record index is the sum of a non-zero index value from bank. FIG. 31a shows a flow chart for the highest order bank process. INPUT is the index value at the current symbol value location in the masked input index table 67. OUTPUT is the index value from the result index table 2900 for the same location. FIGS. 31b and 31c are continuations of the flow chart for the next lower order bank processes. A partial index sum INPUT-COUNT and OUTPUT-COUNT is kept for each bank. FIG. 31d illustrates the lowest order bank process where all INUSE=true records are copied from the input record memory to the results record memory. Each record is stored at a location which is the sum of the index values from the result index table 2900 of FIG. 29. Although preferred and alternative embodiments of the present invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions of parts and elements without departing from the spirit of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Data communication between computers has become a standard part of worldwide networks in many areas of endeavors. These individual networks gather data about diverse subjects and exchange information of common interest among various media groups. Most of these networks are independent communication entities that are established to serve the needs of a particular group. Some use high speed connections while others use slow speed networks. Some use one type of protocol while others use a different type of protocol. Other well-known differences between networks also exist. There has been considerable effort expended in an attempt to make it possible to interconnect disparate physical networks and make them function as a coordinated unit. Whether they provide connections between one computer and another or between terminals and computers, communication networks are divided basically into circuit-switched or packet-switched types. Circuit-switched networks operate by forming a dedicated connection between two points. Such a dedicated circuit could be represented by a telephone connected through a circuit from the originating phone to a local switching, office, across trunk lines to a remote switching office and finally to the destination telephone. When that circuit is complete, no other communications can travel over the wires that form the circuit. The advantage of such circuit lies in the fact that once it is established, no other network activity will decrease the capacity of the circuit. The disadvantage is that concurrent communication cannot take place on the line or circuit. Packet-switched networks take an entirely different approach. In such system, traffic on the network is divided into small segments of information called packets that are multiplexed on high capacity intermachine connections. Each packet carries identification that enables other units on the network to know whether they are to receive the data or are to transmit it to another destination. The chief advantage of packet-switching is that multiple communications among information sources such as computers can proceed concurrently with connections between machines being shared by all machines that are communicating. The disadvantage is that as activity increases, a given pair of communicating devices can use less of the network capacity. A new technology has been developed that is called Internet and it accommodates information or communication networks having multiple, diverse underlying hardware technologies, or physical media protocols, by adding both physical connections and a new set of conventions. One of the problems with the use of Internet is that addresses refer to connections and not to the device itself that is sending the information. Thus, if a communication source, such as an aircraft for example, moves from one communication network to another, its Internet address must change. Specifically, if an aircraft is transmitting a particular location address code in one communication network in the Internet system and it moves to another, its Internet address must change. It is similar to a traveler who has a personal computer operating with a first communication network. If the computer is taken on a trip and connected into the information system after reaching the new destination, a new location address for the computer must be obtained for the new destination. It is also similar to moving a telephone from one location to another. A new telephone number must be assigned to the telephone at the new location. The telephone cannot be reached at the new location with the old number. Further, when routing a signal from one station to another through a plurality of nodes forming multipath connections, the message format contains a destination location address that is used to make the routing decisions. When the system has multiple addresses, the route taken by the packets traveling to a particular station address depends upon the location code embedded in the station address. Thus, two problems occur in such message communication networks. The first is the requirement to change the address code of the communication source when it is at different locations in the network and the second is routing the message to the receiver if the address has changed. It can be seen, then, that with the presently existing system, if host A transmits a message to host B with a specific location code, by the time the message arrives at that location, host B may have moved to a new information processing network and changed its location code to conform to the new system and thus could not receive the message transmitted by host A. Host A must know that host B has entered the new information processing system and then must change the format of the new location address in order to contact host B. The present system overcomes the disadvantages of the prior art by simply assigning a fixed, unique and unchanging identification code to both host A and host B. As host B enters into a new network access system, it transmits its identification code to the nearest node and all of the nodes interconnecting all of the disparate networks each store, with the unique identification code of host B, the address of those nodes which can communicate with host B so that a path can be completed through the nodes between host A and host B. In the prior art, hierarchical logical routing is used to address highly mobile end-systems (computers on ships and aircraft, etc.) that are simultaneously connected to multiple communication paths and employ multicast message traffic. Hierarchical routing schemes have great difficulty solving this combined set of problems and a new approach must be used to overcome the difficulties in using hierarchical routing to meet the user's diverse requirements. Further, in the prior art, a logical network address of larger than 32 bits was too large to be used as a directory access method to locate a receiver at a location address specified in the message format. Specialized hierarchical address structures which embed network location information have been employed to reduce the size of the access index to the routing table and also to reduce the size of the routing table. This approach couples the address structure to the Internet routing software design. There are various “hidden assumptions” of hierarchical addressing. These “hidden assumptions” are (1) the processing load of the router CPU increases as the size of the routing table increases and (2) computer memory is a scarce and expensive resource. The present invention overcomes the first of these problems while computer memory technology has addressed the second problem by making very large memories cost effective. Traditional approaches for designing a network address structure have either been intimately entwined in the design of efficient routing look-up tables or assigned by a central authority such as ARPANET. Neither of these approaches gives much if any thought to the needs, desires or ease of use of the group which must make operational use of the system. In an age of fourth generation database languages and high level compilers, network addresses are basically hand-coded in low level language. Addresses and address structures are difficult to change as a mobile end-unit moves from one communication network to another. Experts are often required to ensure that operational equipment is properly integrated into the system. ISO (International Standards Organization) addressing provides a basis for a much better approach but the overall design and administration of a network addressing structure must be elevated to an easily supported, user friendly, distributed architecture to effectively support the user's long-term needs. Traditional directory access methods, whether for Internet routing, databases or compiler symbol tables, fall into three basic categories: (1) Sorted Tables. The keys are sorted by some rule which allows a particular search strategy (e.g., binary search) to locate the key. Associated with the key location is a pointer to the data. (2) Tree Structures. Parts of the key field are used to traverse a tree data structure to a leaf node which holds the data or a pointer to the data. (3) Hashing. Some arithmetic function is applied to the key which compresses the key field into a chosen integer range which is the initial directory size. This integer is the index into the directory which usually contains a pointer to the data. Each of these techniques has advantages and disadvantages when applied to the Internet routing table access design. Sorted tables provide the potentially most compact storage utilization at the cost of having access computations which grow with the number of addresses (keys) active in the system. Computations for sorted tables grow proportional to the log of the number of keys plus one. Using sorted tables, the router processing will slow down as the number of active addresses increases. But the desirable result is to make computation independent of the number of active addresses. It has been theorized, without providing a method, that a scheme to access sorted tables could exist which always allows access in two probes. To date, no methods have been proposed which approaches this theoretical result. Tree data structures have been widely employed for directories, particularly for file systems, such as the UNIX file system where larger amounts of auxiliary disc storage is being managed. Trees offer access times that are proportional to the length of the address (key). Trees trade off memory space for processing load. More branches at each level decreases the processing but uses much more memory. For example, a binary tree uses two locations at each level for each bit in the address field for which there is an active address. The binary tree processing of an eight bit octet requires eight memory accesses as well as unpacking the bits from the octet. On the other hand, processing a 256 way tree takes one memory access using the address octet as an index at each level. A 256 way tree requires 256 locations at the next level for every different octet active (a valid value) at the current level. An address of six octets with ten valid octet values in each octet position would require 256×10 6 (256 million) locations, rapidly reaching an unrealizable size on current computer equipment. With current realizable computer memory sizes, pure tree structures do not appear to offer a viable structure for real time, address independent directory access method. Hashing has often been used over the last several decades to create directories where fast access is desired. One system uses a multi-level hashing scheme as the file system directory structure. The Total database system is based on hashed key access. Many language compilers use hash tables to store symbols. Hash table schemes have good average access costs—often a single access, but can degrade drastically when the table becomes too full or the hashing function does not perform a good job of evenly distributing the keys across the table. Some techniques called “linear hashing” and “dynamic hashing” have provided the method of expanding the hash table when a particular bucket becomes too full instead of using the traditional linked list overflow methods. These techniques generally require about 40% more space than the number of active addresses (keys) to achieve single access speed without employing overflow methods. All general hashing techniques use a variation of several common randomizing functions (such as dividing the key by a prime number and using the remainder) to “compress” the key field into a much smaller integer index into the hash table. Hashing functions have traditionally been viewed as one-way, randomized mapping of the key set into the hash space. The index computed by the hashing function could not be used to reconstruct the key. If for a particular hash function there exists a reciprocal function which maps the index to the unique key which generated the index, then the compressed keys could be stored in the directory. The present invention overcomes the disadvantages of the prior art by considering a flat, as opposed to hierarchical, logical routing address space with unique identifiers assigned to each transmitter and receiver to vastly simplify the modern communication problems of addressing highly mobile end-systems which are simultaneously connected to multiple communication paths and employ multicast message traffic. Further, the present invention employs a reversible arithmetic code compression technique to reduce the logical network address of up to 128 bits to a unique integer value which preserves any hierarchical ordering of the network address. Also, the present invention employs dynamic hashing and memory allocation techniques to automatically adjust the size of the routing table directory and routing records to accommodate the number of end-system addresses currently active in the communication system. These techniques provide a selection of approaches to allow graceful degradation of the routing efficiency when the memory available for routing tables is full. Finally, the system improves over the prior art by using a message format that is structure independent of the location of the destination of the message receiver. Arithmetic coding, when applied to addresses as known length keys, provides several advantages for table look-up when the addresses are known or can be learned in advance as they are in communications applications. The proposed arithmetic coding routing table design provides direct support for mobile, multi-homed, shared network end-systems employing multicast and unicast messaging while minimizing the effects of the “hidden assumptions” that have lead to reducing the routing table size by embracing hierarchical routing schemes. First, the identification encoding parameter tables are easily constructed by counting the occurrence of a particular symbol value and the accumulative distribution over all octet occurrences. That is, the tables are scaled to the statistical occurrence of each octet value. When a “bucket” overflows, dynamic hashing approaches can be used to expand the directory or parameter tables. Secondly, arithmetic coding can be constructed to operate on each symbol position in the address field as it arrives, allowing processing to begin as soon as the first address symbol arrives. Thirdly, arithmetic coding preserves the hierarchical (left to right precedence) of the ISO addresses being encoded. This is desirable if an Internet router only has knowledge of the network address but the Internet header carries the full destination address of a succeeding system node. Finally, a constant known set of computations is required for each symbol of the address field independent of the number of address symbols or the number of active Internet addresses. These features make the arithmetic coding used herein an ideal candidate for the routing table directory structure that is independent of a location address in a router, gate way or end-system. The present invention provides a very fast, automatically expandable, source filtered Internet routing scheme totally independent of the internal logical or physical structure of the network addresses in the message format that it is routing. Addresses are just unique identification numbers represented by a string of symbols of known length. Each Internet router learns the location of these numbers within the network from the Internet protocol traffic, from the source addresses of the packets it receives, and from a network management protocol. Address independent routing tables provides the following direct benefits: They provide a very fast routing table access scheme that is capable of supporting fast packet switch designs for very high speed media such as FDDI (i.e., routers which begin the outbound transmission of the packet as soon as possible after receiving the Internet header and before the whole packet has been received). They allow source address filtering for efficient multicast operation and security partitioning of the network. They allow independent automatic generation of network addresses from a user name space by a network name service. This facilitates using the same Internet software in disconnected networks with different addressing authorities and different address structures. They allow for orderly expansion, restructuring and redesign of the user name space without changing the Internet code or table structure. They reduce initial system procurement and logistic support costs because no special coding is needed for different networks. They reduce life cycle system costs because the Internet routers automatically adapt to network changes and they can be expanded without routing table modification. The present invention combines arithmetic coding with dynamic hashing to provide a very high speed method and system for detecting the 48 bit physical addresses in a Media Access Controller (MAC). The present system guarantees the acceptance or rejection of a frame. This technique always performs address detection functions within the transmission time of the address field plus a small fixed number of octet clocks depending on the logic implementation chosen. Specifically, the present system provides the following features: (1) variable length addresses with no known internal structure and processed with a number of memory accesses and a processing time proportional to the number of octets in the address field; (2) the size of the routing tables is directly proportional to the number of active addresses known to the router and within the practical limits of currently available microprocessing systems; (3) and the computational operations required to access the routing table for any address is linearly proportional to the length of the address field and these computations are reasonably performed by currently available microprocessor systems. | <SOH> SUMMARY OF THE INVENTION <EOH>Thus the present invention relates to a system for routing a message between a source and a destination and which utilizes a message format that is structure-independent of the location of the message destination, said system comprising at least a first signal transceiver device having only a first fixed unique identification code wherever the transceiver device may be located; at least a second signal transceiver device for communicating with the first transceiver device and having only a second fixed unique identification code wherever the second transceiver device may be located; and routing nodes for coupling a transmitted signal from the first transceiver device to the second transceiver device at an unknown physical location within the system using a routing message format containing only the first and second transceiver fixed unique identification codes and addresses of the routing nodes with a message format that is structure-independent of any transceiver location code. Another aspect of the invention is an apparatus and method for implementing a routing table directory to provide for fast access times to look up routing information. This apparatus is an application of a novel associative memory utilizing arithmetic coding to associate a key presented to the memory with a record stored in the memory, but has a very-wide range of application in many different types of data processing systems. The associative memory includes an index table stored in memory and a record memory for storing the records of data. The index table is constructed such that each symbol of a key, a key being divided into a string of symbols and each symbol being defined by its position within the key and its value, addresses an index value in the index table memory. These index values are assigned such that the sum of index values for a given key is a unique value that is used to address the record memory. Several methods and apparatus are disclosed the permit random assignment of index values to new keys as they are presented, as well as for keys that are presented in sorted order for addition to the memory. Another aspect of the invention provides a method and apparatus for utilizing use-count tables created by the arithmetic coding process to determine the maximum number of key sets resulting from the set operations union and intersection, used to combine two or more different key sets. The intersection of the key for two or more relational database tables is essentially the relational join operations. This method can perform the relational join operations in a much faster and efficient method than presently utilized joined operations. | 20040716 | 20061205 | 20050324 | 92313.0 | 2 | NGUYEN, HANH N | PACKET SWITCHING NODE | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,892,824 | ACCEPTED | DEVICES FOR CREATING VOIDS IN INTERIOR BODY REGIONS AND RELATED METHODS | Several embodiments of cutting tips for tools for creating voids in interior body regions are provided. The cutting tips provide for rotational and translational cutting. An actuator mechanism for deploying a cutting tip converts the rotational movement of a wheel into translational movement of a plunger rod. The actuator mechanism provides positive cutting action as the cutting tip is moved from a first, non-deployed position to a second, deployed position and from the second, deployed position to the first, non-deployed position. Methods of creating a void in bone provide one or more mechanical cutting tools that may be used in combination with one or more expandable void-creating structures to form a void of a desired size and configuration. | 1. A method of creating a void in bone comprising establishing a percutaneous access path leading into a bone, introducing through the access path a tool having a cutting tip that extends radially from the access path to contact bone, manipulating the cutting tip in cancellous bone to create a void in the cancellous bone, withdrawing the tool, introducing a first expandable structure through the access path, the expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, expanding the first expandable structure in the cancellous bone to enlarge or further define the void, withdrawing the first expandable structure, introducing a second expandable structure through the access path, and expanding the second expandable structure in the cancellous bone to enlarge or further define the void. 2. A method according to claim 1, further comprising introducing a filling material into the void. 3. A method according to claim 1, further comprising, withdrawing the second expandable structure. 4. A method according to claim 1 wherein the second expandable structure is of a different size than the first expandable structure. 5. A method according to claim 1 wherein the second expandable structure is of a different configuration than the first expandable structure. 6. A method according to claim 1 wherein the second expandable structure is of the same size and configuration as the first expandable structure. 7. A method according to claim 1 wherein at least one of the first and second expandable structures is a balloon. 8. A method of creating a void in bone comprising establishing a percutaneous access path leading into a bone, introducing through the access path a first tool having a cutting tip that extends radially from the access path to contact bone, manipulating the cutting tip in cancellous bone to create a void in the cancellous bone, withdrawing the first tool, introducing an expandable structure through the access path, the expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, expanding the expandable structure in the cancellous bone to enlarge or further define the void, withdrawing the expandable structure, introducing through the access path a second tool having a cutting tip that extends radially from the access path to contact bone, and manipulating the cutting tip of the second cutting tool in the cancellous bone to enlarge or further define the void. 9. A method according to claim 8, further comprising introducing a filling material into the void. 10. A method according to claim 8 wherein the cutting tip of the second tool is of a different size than the cutting tip of the first tool. 11. A method according to claim 8 wherein the cutting tip of the second tool is of a different configuration than the cutting tip of the first tool. 12. A method according to claim 8 wherein the cutting tip of the second tool is of the same size and configuration as the cutting tip of the first tool. 13. A method according to claim 8 wherein the expandable structure is a balloon. 14. A method of creating a void in bone comprising establishing a percutaneous access path leading into a bone, introducing through the access path a first tool having a cutting tip that extends radially from the access path to contact bone, manipulating the cutting tip of the first tool in cancellous bone to create a void in the cancellous bone, withdrawing the first tool, introducing through the access path a second tool having a cutting tip that extends radially from the access path to contact bone, manipulating the cutting tip of the second tool in the cancellous bone to enlarge or further define the void, withdrawing the second tool, introducing an expandable structure through the access path, the expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, and expanding the expandable structure in the cancellous bone to enlarge or further define the void. 15. A method according to claim 14, further comprising withdrawing the expandable structure. 16. A method according to claim 14, further comprising introducing a filling material into the void. 17. A method according to claim 14 wherein the expandable structure is a balloon. 18. A method according to claim 14 wherein the cutting tip of the second tool is of a different size than the cutting tip of the first tool. 19. A method according to claim 14 wherein the cutting tip of the second tool is of a different configuration than the cutting tip of the first tool. 20. A method according to claim 14 wherein the cutting tip of the second tool is of the same size and configuration as the cutting tip of the first-tool. 21. A method of creating a void in bone comprising establishing a percutaneous access path leading into a bone, introducing a first expandable structure through the access path, the first expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, expanding the first expandable structure in cancellous bone to create a void, withdrawing the first expandable structure, introducing a second expandable structure through the access path, the second expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, expanding the second expandable structure in the cancellous bone to enlarge or further define the void, withdrawing the second expandable structure, introducing through the access path a tool having a cutting tip that extends radially from the access path to contact bone, and manipulating the cutting tip in the cancellous bone to enlarge or further define the void. 22. A method according to claim 21, further comprising introducing a filling material into the void. 23. A method according to claim 21 wherein the second expandable structure is of a different size than the first expandable structure. 24. A method according to claim 21 wherein the second expandable structure is of a different configuration than the first expandable structure. 25. A method according to claim 21 wherein the second expandable structure is of the same size and configuration as the first expandable structure. 26. A method according to claim 21 wherein at least one of the first and second expandable structures is a balloon. 27. A method of creating a void in bone comprising establishing a percutaneous access path leading into a bone, introducing a first expandable structure through the access path, the first expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, expanding the first expandable structure in cancellous bone to create a void, withdrawing the first expandable structure, introducing through the access path a tool having a cutting tip that extends radially from the access path to contact bone, manipulating the cutting tip in the cancellous bone to enlarge or further define the void, withdrawing the tool, introducing a second expandable structure through the access path, the second expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, and expanding the second expandable structure in cancellous bone to enlarge or further define the void. 28. A method according to claim 27, further comprising introducing a filling material into the void. 29. A method according to claim 27 wherein the second expandable structure is of the same size and configuration as the first expandable structure. 30. A method according to claim 27 wherein the second expandable structure is of a different size from the first expandable structure. 31. A method according to claim 27 wherein the second expandable structure is of a different configuration from the first expandable structure. 32. A method according to claim 27 wherein at least one of the first and second expandable structures is a balloon. 33. A method according to claim 27 withdrawing the second expandable structure. 34. A method of creating a void in bone comprising establishing a percutaneous access path leading into a bone, introducing an expandable structure through the access path, the expandable structure being adapted to undergo expansion in cancellous bone to compact cancellous bone to create a void in the cancellous bone, expanding the expandable structure, introducing through the access path a first tool having a cutting tip that extends radially from the access path to contact bone, manipulating the cutting tip in the cancellous bone to enlarge or further define the void, withdrawing the first tool, introducing through the access path a second tool having a cutting tip that extends radially from the access path to contact bone, and manipulating the cutting tip of the second tool in the cancellous bone to enlarge or further define the void. 35. A method according to claim 34, further comprising introducing a filling material into the void. 36. A method according to claim 34 wherein the expandable structure is a balloon. 37. A method according to claim 34 wherein the cutting tip of the second tool is of a different size than the tip of the first tool. 38. A method according to claim 34 wherein the cutting tip of the second tool is of a different configuration than the tip of the first tool. 39. A method according to claim 34 wherein the cutting tip of the second tool is of the same size and configuration as the cutting tip of the first tool. | RELATED APPLICATION This application claims the benefit of provisional U.S. application Ser. No. 60/499,934, filed Sep. 3, 2003, and entitled “Mechanical Devices for Creating Voids in Interior Body Regions and Related Methods.” FIELD OF THE INVENTION This invention relates generally to tools for creating cavities or voids in interior body regions. In particular, the invention relates to creating voids in bone for diagnostic or therapeutic purposes. BACKGROUND OF THE INVENTION A minimally invasive method of forming a cavity or void within one of the body's solid organs, for both diagnostic and treatment purposes, is becoming increasingly important as radiological and other types of scanning techniques improve a physician's ability to view inside the body without having to make an incision. The most common solid organ currently making use of a minimally invasive technique to form a void is bone. Typically this is any pathological bone in the body with a fracture, osteoporosis, or a tumor. The most commonly used void-forming method for bones is the inflatable bone tamp, as described in U.S. Pat. Nos. 4,969,888 and 5,108,404. Void formation in this case is usually followed by filling with a filling substance like bone cement or a bone substitute. Mechanical methods are also available for making voids inside solid organs. Those solid organs include the brain, the kidneys, the spleen, the liver and bone. In the brain, for example, an abscess could be easily debrided and irrigated with a minimally invasive mechanical void technique. A fractured spleen could be approached with a minimally invasive technique, to make a small void to fill with gelfoam or some other coagulant to stop hemorrhage. An osteoporotic, fractured vertebral body or bone tumor could be approached by a minimally invasive mechanical system in order to create a cavity or void and then refill with a bone substitute. A demand exists for systems or methods that are capable of forming voids in bone and other interior body regions in safe and efficacious ways. SUMMARY OF THE INVENTION The invention provides systems and methods for creating voids in interior body regions. One aspect of the invention provides a cutting tip for cutting or scraping bone. In one embodiment, a curette-type instrument at the end of a shaft can be mechanically angled into different positions to scrape material to form a void. In another embodiment, a mechanical device at the end of a shaft resembles a T-type configuration and allows both translational and rotational cutting to form a void. In a third embodiment, the cutting tip includes a turned and tapered trunk. In a fourth embodiment, the cutting tip includes a conical trunk. In a fifth embodiment, a sharp, stout, metal spring is provided on the end of a shaft. In a sixth embodiment, the distal end of a shaft carries two or more fingers to grab tissue for extraction. In a seventh embodiment, a hinged void-forming device is carried by a shaft and allows for formation of a void, which may be of a rectangular or any other pre-determined shape. Another aspect of the invention provides an actuator mechanism for deploying a cutting tip. In one embodiment, rotational movement of a thumbwheel is converted to translational movement of a plunger rod. In an alternative embodiment, rotational movement of a control knob is converted to translational movement of a plunger rod through interaction of a series of gears. Another aspect of the invention provides a tool for creating voids in interior body regions. The tool comprises a shaft, a tip for contacting bone, and a hinge member coupling the tip to the shaft. The tip becomes uncoupled if the torque applied exceeds a maximum hinge torque. The shaft includes a region of weakness proximal to the tip along which the shaft will break if the torque applied exceeds a maximum shaft torque. The maximum hinge torque is greater than the maximum shaft torque. According to another aspect of the invention, a tool for creating voids in interior body regions comprises a shaft assembly including a lumen, a tip for contacting bone coupled to the shaft, and a rod slidable within the lumen. The rod is tethered to the tip. According to another aspect of the invention, a tool for creating voids in interior body regions comprises a shaft including a lumen, and a tip for contacting bone coupled to the shaft by a coupling element. The tip is additionally tethered to the shaft such that the tip remains tethered to the shaft if the coupling element becomes inoperable. According to another aspect of the invention, a tool for creating voids in interior body regions comprises a cannula and a shaft. The shaft has a handle and is sized and configured for passage through the cannula. A projection extends radially from the shaft to restrict forward advancement of the shaft within the cannula. Another aspect of the invention provides methods of creating a void in bone. The methods provide one or more mechanical cutting tools that may be used in combination with one or more expandable void-creating structures to form a void of a desired size and configuration. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a mechanical tool for creating voids in interior body regions and illustrating pivoting movement of the cutting tip in phantom. FIG. 2 is a perspective view of a bone treatment device. FIG. 3 is a perspective view illustrating insertion and use of the device of FIG. 2 in a vertebra. FIG. 4 is a perspective view of an alternative embodiment of a cutting tip and illustrating pivoting movement of the tip in phantom. FIG. 5 is a front plan view of the tip shown in FIG. 4 and illustrating rotational movement of the cutting tip. FIG. 6 illustrates 180° rotational movement of the cutting tip in a vertebra to create a 180° void. FIG. 7 illustrates the shaft rotated 180° relative to FIG. 6 and the cutting tip again rotated 180° to form a 360° void. FIG. 8 is a side view of the tip shown in FIG. 4 and illustrating translational movement of the cutting tip in a sawing-like motion. FIG. 9 illustrates the translational movement of the cutting tip and formation of a void in a vertebra. FIG. 10 is a perspective view illustrating the use of a marker band to identify the position of the cutting tip in relation to the distal end of the cannula. FIG. 11 is a perspective view illustrating use of a stop to limit translational advancement of the shaft within a cannula. FIG. 12A is an enlarged view of a groove located on the shaft of the cutting tool. FIG. 12B is a perspective view of an alternative embodiment of a shaft in which a portion of the shaft is formed of a material of reduced strength and/or rigidity relative to the rest of the shaft. FIG. 13 is a perspective view of an alternative embodiment of a stop that limits translational and rotational movement of the shaft along and within the cannula. FIG. 13A is a perspective view of an alternative embodiment of a T-shaped slot that limits translation and rotational movement of the shaft along and within the cannula. FIG. 14 is a schematic view representing the preset size and configuration of a void formed by performing a full sweep motion of a cam follower along a cam surface. FIG. 15 is a perspective view of an alternative embodiment of a cutting tip and illustrating pivoting movement of the tip in phantom. FIG. 16 is a front plan view of the tip shown in FIG. 15 and illustrating rotational movement of the cutting tip. FIG. 17 is a perspective view of an alternative embodiment of a cutting tip and illustrating pivoting movement of the tip in phantom. FIG. 18 is a front plan view of the tip shown in FIG. 17 and illustrating rotational movement of the cutting tip. FIG. 19 is a sectional view of an actuator mechanism for deploying a cutting tip and showing placement of the tool in the user's hand. FIG. 20 is a close-up and partial sectional view of the thumbwheel, threaded cap, flange, and stop of FIG. 19. FIG. 21 is a cut-away view of the tether and hinge mechanism of the cutting tip. FIG. 22 is a side sectional view of an alternative embodiment of an actuator mechanism in which a lever actuates movement of the plunger rod. FIG. 23 is a perspective view of a tool incorporating an alternative embodiment of an actuator mechanism. FIG. 24 is a top sectional view of an alternative embodiment of an actuator mechanism. FIG. 25 is a side sectional view of an alternative embodiment of an actuator mechanism and showing placement of the tool in the user's hand. FIG. 26 is a side partial section view illustrating an alternative embodiment of a mechanical bone cutting tool illustrating the cutting tip in a straightened or malleable state and retracted within a cannula. FIG. 27 is a view similar to FIG. 26 and illustrating advancement of the cutting tip beyond the distal tip of the cannula and the introduction of fluid to activate the cutting tip. FIG. 28 is a view similar to FIG. 27 and illustrating activation of the cutting tip to a predetermined configuration. FIG. 29 is a side view of an alternative embodiment of a cutting tip illustrating the cutting tip in a straightened or malleable state. FIG. 30 is a view similar to FIG. 29 illustrating the cutting tip in the activated state. FIG. 31 is a side view of an alternative embodiment of a cutting tip illustrating the cutting tip in a straightened or malleable state. FIG. 32 is a view similar to FIG. 31 illustrating the cutting tip in the activated state. FIG. 33 is a side view of an alternative embodiment of a cutting tip carried by a shaft and illustrating a dual lumen extending through the shaft into the cutting tip. FIG. 34 is a side view of an alternative embodiment of a cutting tip illustrating a throughbore extending through the cutting tip. FIG. 35A is a side view illustrating a pre-bent or formed cutting tip confined by a cannula. FIG. 35B is a side view similar to FIG. 35A illustrating the deployment of the pre-bent or formed cutting tip by extension of the tip beyond the cannula. FIG. 36 is a side view of an alternative embodiment of a mechanical void-creating device. FIG. 37 is a side view of an alternative embodiment of a mechanical void-creating device. FIG. 38 is a side view of an alternative embodiment of a mechanical void-creating device. FIG. 39 is a top view of the device shown in FIG. 38. FIG. 40 is a side view of an alternative embodiment of the device of FIGS. 38 and 39 in which spring blades extend from the device. FIGS. 41A-D illustrate a method of creating and filling a void in bone in which a first mechanical cutting tool is used to create a void in bone and a second mechanical cutting tool is used to expand and/or further define the void. FIGS. 42A-E illustrate an alternative method of creating and filling a void in bone in which a first mechanical cutting tool is used to create a void in bone and a second mechanical cutting tool and then an expandable body are used to expand and/or further define the void. FIGS. 43A-D illustrate an alternative method of creating and filling a void in bone in which a first expandable body is used to create a void in bone and a second expandable body is used to expand and/or further define the void. FIGS. 44A-E illustrate an alternative method of creating and filling a void in bone in which a first expandable body is used to create a void in bone and a second expandable body and then a mechanical cutting tool are used to expand and/or further define the void. FIGS. 45A-E illustrate an alternative method of creating and filling a void in bone in which a first expandable body is used to create a void in bone and a mechanical cutting tool and then a second expandable body are used to expand and/or further define the void. FIGS. 46A-E illustrate an alternative method of creating and filling a void in bone in which an expandable body is used to create a void in bone and a first mechanical cutting tool and then a second mechanical cutting tool are used to expand and/or further define the void. FIGS. 47A-E illustrate an alternative method of creating and filling a void in bone in which a first cutting tool is used to create a void in bone and an expandable body and then a second mechanical cutting tool are used to expand and/or further define the void. FIGS. 48A-E illustrate an alternative method of creating and filling a void in bone in which a mechanical cutting tool is used to create a void in bone and a first expandable body and then a second expandable body are used to expand and/or further define the void. DESCRIPTION OF THE PREFERRED EMBODIMENT Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention that may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. The systems and methods embodying the invention can be adapted for use virtually in any interior body region, where the formation of a cavity or void within tissue is required for a therapeutic or diagnostic purpose. The preferred embodiments show the invention in association with systems and methods used to treat bones. This is because the systems and methods which embody the invention are well suited for use in this environment. It should be appreciated that the systems and methods which embody features of the invention can be used in other interior body regions, as well. Various embodiments of cutting tips are described below in detail. In each case their sizes and shapes could be produced to fit the ideal void to be formed, whether it is a void in a tibia or a vertebral body. In addition, these mechanical tools could be made of any bio-compatible metal (for example, but not limited to stainless steel, titanium, titanium alloys, tantalum, aluminum, aluminum alloys, or other metals) that has adequate shear and tensile strength to perform their void-forming function. Plastic polymers having suitable biomechanical properties may also be used for these tools. Alternatively, the tool may be plated or coated with a biocompatible material. I. Mechanical Cutting Tool A. Curette FIGS. 1-3 show a tool 10 capable of forming a cavity or void in a targeted treatment area. The tool 10 comprises a shaft 12 having a proximal and a distal end, respectively 14 and 16. The shaft 12 preferable includes a handle 18 to aid in gripping and maneuvering the shaft 12 through a pre-formed access path into bone. The handle 18 can be made of any suitable material, e.g., any rigid polymer or metal or combination thereof, secured about the shaft 12. The handle 18 is desirably sized and configured to be securely and comfortably grasped by the physician. The shaft 12 carries a void-forming structure 20 at its distal end 16. In the illustrated embodiment, the structure 20 takes the form of a multi-faceted cutting tip 20. The cutting tip 20 may be adapted for use in various body regions, e.g., to create a void in bone. The cutting tip 20 may also serve to remove hard or soft tumors from tissue. As used in this specification, a cutting tip is a surface adapted to mechanically form a void in bone through contact with the bone, e.g., by cutting, shearing, scooping, shaving, sciving, dissecting, or scoring of the bone. The cutting tip 20 is hingedly coupled to distal end 16 of the shaft 12. The cutting tip 20 is desirably adapted to extend radially from the shaft 12 and radially from the pre-formed access path to a diameter that is greater than a diameter of the access path. The cutting tip 20 can be made of any suitable biocompatible material, e.g., stainless steel, cobalt chromium, titanium and alloys or mixtures thereof. The shaft 12 and cutting tip 20 can alternatively be made of different materials (e.g. alloys of stainless steel with different strengths: 303 stainless steel, 304 stainless steel, 17-4 stainless steel, 17-7 stainless steel) and welded or otherwise bonded together. As will be described in detail later, an actuator, e.g., wheel 22 (see also, e.g., FIGS. 19 and 23), permits selective movement of the cutting tip 20 from a first, closed or non-deployed position to a second, open or deployed position. In the closed position (represented by solid lines in FIG. 1), the cutting tip 20 extends from the distal end 16 of the shaft 12 along the axis S of the shaft 12. In this position, the shaft 12 can be easily passed through a cannula 23 or other instrument. The hinge mechanism permits pivoting of the tip 20 at an angle A transverse to axis S of shaft 12 to the opened position (represented in phantom in FIG. 1). In a preferred embodiment, the cutting tip 20 is adapted to pivot and be selectively secured in any pivot position from 0-90° relative to the axis S of the shaft 12. Desirably, the actuating mechanism provides positive, controlled movement in both directions (i.e., from the open, deployed position to the closed, non-deployed position and from the closed, non-deployed position to the open, deployed position) during all degrees of actuation. That is, the secured pivot position and angle A are maintained regardless of the rotational orientation of the shaft 12. The actuator mechanism provides positive cutting action as the tip is actuated in either direction to provide bi-directional cutting. Actuation may be repeated so as to provide continuous cutting. The speed of actuation may be varied to vary the speed of cutting. The cutting tip 20 also permits translational (i.e., longitudinal) movement along the axis S of the shaft 12 in a push-pull or sawing motion with the tip in the deployed position. The physician creates a desired void by repeated actuation, translational movement, or by performing a series of combined actuation and translational movements. In use, the cutting tip 20 is placed in the closed position extending from the distal end 16 of the shaft 12, i.e., at a 0° angle A relative to axis S. The tool 10 may be introduced into a targeted treatment site through an open procedure. Desirably, the tool 10 is introduced in a closed and minimally invasive procedure in which a percutaneous cannula 23 is advanced into a desired treatment region, e.g., a vertebral body 37. The shaft 12 is then passed through the cannula 23 and the cutting tip 20 is extended beyond the distal end of the cannula 23. Alternatively, the cannula 23 may be removed after introduction of the tool 10. Fluoroscopy or other visualization techniques may be employed to aid in introducing the cannula 23 and tool into the targeted treatment area. The cutting tip 12 is then pivoted to a desired position, i.e., preferably any position between 0-150°, and most preferably about 90°. Also, conceivably the tip 20 could deploy in either direction without stopping in the non-deployed condition. Actuation may be repeated and the shaft 12 advanced in fore and aft directions by pushing and pulling in a sawing-like motion to thereby create a void. If rotational cutting is desired, turning of shaft 12 is required to reposition the tip 20 to continue cutting. In this case, the cutting tip 20 is returned to the closed position and the shaft 12 turned or rotated to a new position. The cutting tip 20 is again pivoted to a desired angle A (open position) and the shaft 12 again advanced in fore and aft directions using a push-pull motion. It is apparent that the shaft 12 may be repositioned any number of times to produce a void of a desired configuration. With reference now to FIGS. 2 and 3, the cannula 23 desirably incorporates a distal portion having a reduced profile. The cannula 23 includes a large diameter portion 25, a small diameter distal portion 27, and a transition portion 29. Alternatively, the cannula 23 may provide a taper between the large and small diameter portions 25 and 27 (not shown). The shaft 12 of the tool 10 is desirably sized to fit within a lumen 31 extending through the cannula 23, and may be of a constant or varying size. Desirably, the reduced distal tip diameter of the cannula 23 will allow the tip of the tool 10 to be inserted into the targeted bone, with a corresponding reduction in the size of the access path created in the bone. The smaller diameter section 27 of the cannula 23 will pass through the cortical wall into the bone, while the larger diameter section 25 can abut against the outside of the bone (sealing the opening, if desired), and will desirably stretch, but not tear, softer tissues. In a preferred embodiment, the smaller diameter portion 27 is desirably sized such that, when the larger diameter portion 25 abuts the cortical bone 33 of the pedicle 35, the distal end of the smaller diameter portion 27 extends through the pedicle 35 and emerges into the vertebral body 37 and enters into cancellous bone 39. In this embodiment, the tool 10 could be sized such that, when fully inserted into the cannula 23, the distal cutting tip 20 would be prevented from contacting and/or breaching the anterior cortical wall 41 of the vertebral body 37 or targeted bone. Other low profile bone access tools are described in U.S. patent application Ser. No. 09/952,014, filed Sep. 11, 2001, entitled “Systems and Methods for Accessing and Treating Diseased or Fractured Bone Employing a Guide Wire,” which is herein incorporated by reference. B. T-Tip Embodiment In many cases, it is desirable to cut in both a rotational as well as in a translational direction. In such cases, it is preferable that the rotational cutting motion reflects an ergonomic and natural motion for the physician. FIGS. 4-9 illustrate an embodiment of a cutting tool 100 having a cutting tip 120 which permits translational, rotational, or simultaneous translational and rotational movement of the cutting tip using an ergonomic and natural motion. The cutting tip is made from any suitable biocompatible material, e.g., stainless steel. As FIG. 4 illustrates, the cutting tip 120 provides a pivot region 124 hingedly attached to a shaft 112, e.g., pivot pin 126 passes through hole 128 in pivot region 124 and into shaft 112. This arrangement permits a wide range of pivot motion allowing the cutting tip to pivot at virtually any desired angle. In a preferred embodiment, the cutting tip 120 is adapted to pivot from 0-90° relative to the axis S of the shaft 112. Similar to the embodiment of FIG. 1, the actuating mechanism is positive in both directions. A collar 130 divides the pivot region 124 and a trunk region 132 and provides additional strength and support to the cutting tip 120. The maximum width (W) of the trunk 132 is parallel to the axis S of the shaft 112 when the tip 120 is deployed at 90° (illustrated in phantom in FIG. 4). The trunk 132 carries a cutting disc 134 providing a dual rounded cutting surface extending on either side of the trunk 132, providing a 360° cutting surface. In a preferred embodiment, the diameter of disc 134 is approximately the same as the diameter of the shaft 112 so as to minimize stress on the tip 120 during cutting and to provide ease of passage through a cannula. The tip includes a flat or straight cutting surface 136 along the tip of the disc 134 that provides greater ease in cutting bone on the pullback motion. When pushing, the shaft 112 provides the strength and force for cutting. The disc 134 and trunk 132 together provide a large surface contact area that enables the tip 120 to take an aggressive bite into bone and gouge bone material in large chunks. The disc configuration allows rotational cutting in both clockwise and counterclockwise directions. With reference to FIG. 5, the tip 120 is extended to a desired angle A, e.g., 90° along axis T. The shaft 112 is then rotated 0-90° in a first direction (represented by arrow 138) relative to axis T. The shaft 112 can be rotated 0-90° in the opposite direction (represented by arrow 140) relative to axis T to create a void extending 180° by a simple turning of the physician's wrist. FIG. 6 illustrates rotation of the cutting tip 120 in bone, e.g., a vertebra 142, to create a 180° void. In many cases, it may be desirable to create a void extending 360°. As FIG. 7 shows, after formation of a 180° void, the shaft 112 may be rotated 180° and again aligned approximately along axis T. The shaft 112 is then rotated 0-90° in a first direction (represented by arrow 144) relative to axis T. The shaft 112 can be rotated 0-90° in the opposite direction (represented by arrow 146) relative to axis T to create a void extending 360°. The physician can monitor the position of the tip 120 with use of fluoroscopy. The disc configuration also allows translational cutting in a push-pull or sawing motion as represented by arrows in FIGS. 8 and 9. In use, the physician may deliver translational and rotational forces simultaneously by pushing in and pulling out while simultaneously rotating a handle or alternating rotational and translational motions. In this manner, the physician controls rotational and translational movement of the cutting tip 120 to create a void of desired size and shape, e.g., cylindrical. Desirably, as seen in FIG. 10, the shaft 112 carries a boss or stop 102 designed to limit forward, i.e., translational, motion of the shaft 112 within a cannula 104. The diameter of the stop 102 approximates the diameter of the cannula 104 so that the stop 102 rests against the face or top 106 of the cannula 104 to stop forward advancement of the shaft 112 within the cannula 104. The stop 102 is positioned on the shaft 112 such that there is sufficient room to accommodate the physician's fingers wrapped around and under the handle 18. The stop 102 thus provides clearance between the physician's fingers and the percutaneous access cannula 104, preventing pinching or catching of the physician's fingers. The stop 102 stops insertion of the shaft 112 to leave a comfortable working distance for the physician's hand when rotating the shaft 112 (i.e., a sweeping cutting motion) or when using a push-pull cutting motion or a combination of both cutting motions. In a representative embodiment, the stop 102 is positioned approximately 1.75 inches (about 4.5 cm.) from the base of the handle 18. By restricting or preventing further advancement of the shaft 112, the stop 112 prevents advancement of the shaft 112 (and void-forming structure 20) within the vertebral body. This prevents the possibility of puncturing or breaching the anterior cortical wall of the vertebra 142 (see also FIG. 9). Desirably, a marker band 101 is positioned distal of the stop 102. As seen in FIG. 10, when the shaft 112 is fully inserted into the access cannula 104, the marker band 101 is aligned with the face 106 of the cannula 104 as the cutting tip 120 is exiting the cannula 104 into a bone, e.g., a vertebra 142. As shown in FIG. 11, when the shaft 112 is fully inserted into the cannula 104, the tip 120 extends beyond the distal end 103 of the cannula 103. In a representative embodiment, the marker band 101 is located approximately 3 cm. distal of the stop 102. In this embodiment, when the shaft 112 is fully inserted into the cannula 104 (i.e., resting against the stop 102), the tip 120 extends approximately 3.5 cm. from the distal end 103 of the cannula 104 when the cutting tip 120 is in the non-deployed position (i.e., aligned with the axis S of the shaft 112), and approximately 3 cm. from the distal end 103 of the cannula 104 when the tip 120 is in the deployed position (e.g., at 90°). In a preferred embodiment, a groove 105 is positioned proximal the stop 102. As best seen in FIG. 12, the groove 105 is a turned angular cut having an angle G with a radius R on the shaft 112 to define a line of weakness on the shaft 112. In a representative embodiment, the groove 105 is a 60° angular cut (i.e., G=approximately 60°) having a radius R of approximately 0.006 inch. The mean torque required for failure of the shaft 112 at groove 105 (the maximum shaft torque) is less than the torque required for failure of the shaft 112 at pin 126 (the maximum hinge torque) (see also FIG. 4), or more generally, of the cutting assembly itself. For example, it has been found that the mean torque required to scrape normal bone is approximately 2.0 in.-lb. In a representative embodiment, the mean torque required for failure of the shaft 105 at groove 105 is approximately 7.3 in.-lb. and the mean torque required for failure at pin 128 is 9.3 in.-lb. In the event that excessive torque is translated through the shaft 112, the groove 105 results in the shaft 112 breaking or severing at the groove 112 before the tip 120 breaks or fails at the pivot region 124. This provides an additional safety feature that allows the shaft 112 and undeformed pivot region 124 to be safely removed from the cannula 104 without complications. Failure or deformation of the pivot region 124 is avoided. It is contemplated that the region of weakness can also be formed by any of a variety of other suitable means that provide that the shaft 112 will sever or break prior to the tip 120 becoming uncoupled from the shaft 112 (i.e., that provide that the maximum hinge torque is greater than the maximum shaft torque). For example, as shown in FIG. 12B, a portion 111 of the shaft 112 may be formed of a material of reduced strength and/or rigidity relative to the remaining portions 113A and 113B of the shaft 112 to define a region of weakness. In one representative embodiment, shaft portions 113A and 113B are formed of a biocompatible metal and shaft portion 111 is formed of a biocompatible plastic material. With reference to FIG. 13, the shaft 112 may also carry a boss or stop 102 with a tine or lug 108 that selectively mates with a complementary slot or groove 110 in a cannula 104 or other access device so as to limit rotational motion to a preset angle. In this arrangement, the slot or groove 110 defines a cam surface. The tine or lug 108 serves as a cam follower. The configuration of the cam surface and cam follower can vary, but preferably define a system in which a sweep of the cam follower across the full range of motion of the cam surface consistently creates a void of a predetermined size and shape. FIG. 13 shows an embodiment in which the cam surface takes the form of an elongated slot 110 in the circumferential margin of the cannula 104. The depth of reach is defined by the depth of the slot. That is, the length LS of the slot limits forward advancement of the stop 102 (and therefore the shaft 112) within the cannula 104. The width WS of the slot is greater than the width WC of the lug or tine 102 by a pre-determined amount. The angle of rotation is controlled by the extent of the slot 110, i.e., the difference in width between the slot 110 and the width of tine or lug 108 (i.e., the difference between WS and WC). Because the depth of the reach and the angle of rotation are pre-determined and constant, a sweep of the full range of motion of the cam surface and the cam follower consistently creates a void of a predetermined size and shape. For example, FIG. 14 illustrates the formation of a pre-determined pie-shaped void having an angle Al. The pre-determined void has a length corresponding to the length LS of slot 110 as shown in FIG. 13. The slot 110 can be varied, e.g., by varying the width of the slot 110 along its length, to form voids of a desired, pre-determined shape and size. For example, FIG. 13A illustrates an alternative embodiment of a slot 110A in which the slot 110A is generally T-shaped and adapted to form a pre-determined void biased such that the most forward portion is of greater volume, with each volume also being wedge shaped. In use, the tool 100 is introduced into a targeted treatment site. Desirably, the tool 100 is introduced in a closed and minimally invasive procedure in which a percutaneous cannula 104 is advanced into a desired treatment region, e.g., a vertebral body. Introduction of the tool may be assisted by conventional visualization techniques, as previously described. The shaft 112 is then passed through the cannula 104 and the cutting tip 120 is extended beyond the distal end of the cannula 104. The cutting tip 112 is then pivoted to the desired position, i.e., any position between 0-90°. The physician manipulates the cutting tip 120 by sweeping the shaft 112 along the full range of motion of the cam surface and cam follower. The stop 102 serves to limit translational movement of the shaft 112 along the cannula 104 and the lug or tine 108 limits rotational movement of the shaft 112 within the cannula 104 to create a void of a pre-determined size and shape. Because the void created is of a consistent and pre-determined size and shape, visualization is not required during cutting and void formation. The need for fluoroscopy or other visualization techniques is thereby reduced, limiting the patient's exposure to radiation or dyes. Upon completion of the procedure, the cutting tip 112 is returned to the non-deployed position and the cannula 104 and tool 100 are withdrawn. C. Turned and Tapered Trunk Embodiment FIGS. 15 and 16 illustrate an alternative embodiment of a tool 200 for creating voids in interior body regions. In this embodiment, the trunk 232 is tapered and rotated 90° relative to the embodiment shown in FIGS. 4-9 so that the maximum width W of the trunk is perpendicular to the axis S of the shaft 212 when the tip 220 is deployed at a 90° angle A from the axis S of the shaft 212. This arrangement minimizes the combined surface area of the disc 234 and trunk 232 in contact with the bone during scraping and cutting and thus minimizes transmission of significant force and stress to the hinge mechanism. The disc 234 has a convex front surface 248 providing a dome-shape. Preferably, the disc 234 has a diameter that is approximately the same as the diameter of the shaft 212, minimizing stress on the tip 220 during cutting and providing ease of passage of the tip 220 through a cannula. The domed configuration facilitates cutting and scraping of bone by producing leverage on the bone that allows the tip 220 to roll out of the bone easily. The domed configuration allows the tip to easily release from bone and to disengage from the bone for easy withdrawal. The disc 234 provides a 360° cutting surface and permits both translational and rotational movement of the cutting disc 234 when deployed at the desired angle A, as previously described. D. Conical Trunk Configuration FIGS. 17 and 18 illustrate another alternative embodiment of a tool 300 for creating voids in interior body regions. In this embodiment, the trunk 332 is tapered similar to the embodiment of FIGS. 15 and 16, but is conical. The trunk 332 also carries a dome-shaped disc 334 allowing both translational and rotational cutting, similar to the embodiment of FIGS. 15 and 16. The combined cutting surface of the disc 334 and trunk 332 is minimized and is designed to reduce the force and stress on the hinged mechanism by minimizing the contact area in the bone in all directions. The same profile (symmetrical cross-section of the conical trunk 332) is presented to the bone regardless of whether pushing or pulling (translational) force, turning (rotational) force, or a combination of both forces is applied. II. Actuator Mechanism A. Thumbwheel Embodiment FIGS. 19-22 illustrate one embodiment of an actuator mechanism for use with a void-forming tool. The actuator mechanism converts rotational motion into translational movement to control the deployment of a cutting tip. By way of illustration and not limitation, the actuator mechanism is illustrated with the cutting tip 120 embodiment of FIGS. 4-9. The actuator mechanism provides a thumbwheel 150, an insert or cap 152, flange 154, plunger rod 156, and rotational stop 158. The thumbwheel 150, cap 152, flange 154, plunger rod 156, and stop 158 may be made of any suitable metal. The thumbwheel is seated in a free-floating manner in a slot 160 within handle 18. In a preferred embodiment, the handle 18 is made of a strong and durable polymer plastic. The thumbwheel 150 extends, at least in part, from the handle 18 for manipulation by the thumb or index finger of the user, as seen in FIG. 19. The thumbwheel 150 desirably includes grooves or knurls for easy grasping and manipulation. While the thumbwheel 150 may be configured for manual manipulation, it is contemplated that the actuator may also be power-driven. The cap 152 is seated within the thumbwheel 150 and is desirably threaded or otherwise adapted to engage the wheel 150 so as to move with the wheel 150. The cap 152 is connected, e.g., by welding, to the plunger rod 156. The transmission ratio, and therefore the amount of torque delivered, may be controlled by altering the thread pitch of the cap 152. The plunger rod 156 is sized and configured to be seated within the shaft 112 and to extend beyond the shaft 112 and thumbwheel 150 through bores in the cap 152 and thumbwheel 150. In the illustrated embodiment, the thumbwheel 150 and shaft 112 are positioned offset on the handle 18 for placement of the shaft 112 between the index and middle finger, as seen in FIG. 19. As shown in FIG. 21, the distal end of the plunger rod 156 is coupled to tether wire 166. The tether 160 is looped to pass through holes 168 in cutting tip 120 below pin 126 and is swaged or welded to the plunger rod 156. Movement of plunger rod 156 regulates pressure on the tether 160 to actuate the tip 120 between the deployed and non-deployed positions. The tether 160 will keep the tip 120 attached to shaft 112 in the event of breakage or failure of pin 126 to permit easy removal. This prevents parts from being left behind during removal, thereby providing an additional safety feature. While the illustrated embodiment shows the tip 120 coupled to the shaft 112 and additionally tethered to the shaft 112 by a rod 156, it is contemplated that the tip 120 may be additionally tethered to the shaft 112 by any of a variety of ways to provide that the tip 120 remains tethered to the shaft 112 if the coupling element (e.g., pin 126) becomes inoperable. For example, in an alternative embodiment, the tip 120 is additionally tethered to shaft 112 by a cable or pulley (not shown). The flange 154 is seated in a slot 170 within the handle 18 and is coupled to the shaft 112, e.g., by welding or by interference or compression fit. Desirably, the flange 154 includes an offset bore such that there is only one way in which it may be seated with slot 170. The flange 154 engages the shaft 112 within the handle 18 and is sized and configured to essentially prevent rotational movement of the shaft 112. In the illustrated embodiment, the rod 156 has a rectangular end 172 sized and configured to pass through a complementary rectangular opening 174 in the stop 158. The stop 158 engages the rod 156 to prevent rotation of the rod 156 during actuation. The stop 158 is mounted to the plunger rod 156 and seated exterior to and against slot 160. The arrangement of the metal stop 158 against the plastic slot 160 creates additional frictional forces to provide additional strength and reinforcement and serves to limit the amount of torque delivered to the plunger rod 156. Rotation of the thumbwheel 150 in a first direction advances the plunger rod 156 in a first direction along the shaft 112 to decrease tension on wire 166 and actuate deployment of the cutting tip 120. Rotation of the thumbwheel 150 in the opposite direction advances the plunger rod in the opposite direction within the shaft 112 and increases tension on wire 166 to actuate movement of the cutting tip 120 from the deployed to the non-deployed position. This arrangement converts the rotational movement of the thumbwheel 150 into the translational movement of the plunger rod 156. In an alternative embodiment, shown in FIG. 22, a lever 176 is hingedly attached to the plunger rod 156. Movement of the lever 176 in a first direction advances the plunger in a first direction to deploy the cutting tip 120, and movement of the lever 176 in the opposite direction advances the plunger 156 in a second direction to move the cutting tip 120 from the deployed to the non-deployed position. In this manner, the lever 176 permits the physician to continuously and conveniently move the tip 120 itself without moving the shaft 112 to create a reciprocating cutting motion. B. Gear Embodiment FIGS. 23-25 illustrate an embodiment of an actuator similar to the embodiment of FIGS. 19-21. The actuator provides a series of gears that interact to convert rotational motion to translational motion. A central gear 178 is similar in configuration and function to the thumbwheel 150 shown in FIGS. 19-21. The central gear 178 and shaft 112 are centered along the bottom of the handle 18 for placement of the shaft 112 between the middle and ring fingers. Control knobs 180A and 180B are provided at each end of the handle 18 for actuation by the user's thumb. Alternatively, the control knobs 180A and 180B may be driven by a motor. Each control knob 180A and 180B defines a gear that actuates a corresponding intermediate gear 182A or 182B positioned between the control knob 180A or 180B and the central gear 178. Rotation of the control knob 180A or 180B actuates the corresponding intermediate gear 182A or 182B and the central gear 178. Rotational movement of the control knob 180 is thereby converted into translational movement of the plunger rod 156, similar to the previous embodiment. The symmetric design is designed for easy use by either the right or left hand. Further, the symmetric design allows easy rotation of the handle 18. In use, the shaft 112 is advanced through a cannula 104. The cutting tip 120 is extended beyond the distal end of the cannula 104. A control knob 180A or 180B is rotated to deploy the cutting tip 130 to the desired angle. The physician then creates a desired void by performing a series of translational and rotational movements of the shaft 112. The physician then returns the cutting tip 120 to the non-deployed position. If desired, the handle 18 can then be rotated 180°. The opposing control knob 180A or 180B is then manipulated to again deploy the cutting tip 120 to a desired angle and another series of translational and rotational movements may be performed. Once the desired void is created, the physician returns the tip 120 to the non-deployed position. The tool 100 is withdrawn from the patient. The physician then completes the procedure by filling the void with a bone cement or bone substitute, removing the cannula 104, and closing the incision. The rate and/or force of cutting may be controlled by altering the transmission ratio. The force may be varied by varying the screw thread pitch or the transmission gear ratio. The rate of motion (i.e., speed of actuation) may be varied by manually or mechanically varying the speed of actuation. III. Alternative Embodiments of Mechanical Void Creators A. Shape Memory Alloys FIGS. 26-28 illustrate an embodiment of a tool 700 employing a cutting tip 720 formed of a shape memory alloy. Use of a shape memory alloy allows for a smaller instrument as the hinge mechanism is no longer needed to activate the tip. Smaller instruments are safer and can access smaller vertebral bodies located higher in the spine. Smaller instruments are also less invasive and are less traumatic to the patient, allowing for a faster recuperation time. A malleable rod 701 formed of a shape memory alloy, e.g., Nitinol, is provided. It is contemplated that the rod 701 may be of a variety of different diameters, tip configurations, and actuation angles. The rod 701 has a malleable or straightened state (FIGS. 26 and 27) and an activated or articulated predetermined, desired state (FIG. 28). The rod 701 is sized and configured for passage in a straightened or malleable state through a cannula 104 into a vertebra or any bone surface. Once inserted into the bone, the rod 701 returns to its predetermined, desired memory shape as a result of either the body temperature of the patient or by means of an electrical impulse (e.g., cooling, heat, voltage, etc.). For example, the distal end of the rod 701 is activated to an angle, e.g., 90°, to form an elbow defining a cutting tip, as shown in FIG. 28. In a representative embodiment, the length from the distal end of the rod to the bend is approximately 0.5 cm. Cutting of the bone is accomplished by a rotating motion or a push-pull motion or a combination of both motions, as previously described. The rod 701 desirably includes a lumen 703 that permits introduction of a cooling or heating media (S), e.g., saline, to return the rod 701 to a straightened state allowing for easy withdrawal. In another embodiment, the rod 701 is formed from a shape memory alloy with an activation temperature that is equal to room temperature, i.e., the rod 701 is fully austenitic at room temperature. Therefore, the rod 701 is fully articulated to its predetermined shape at room temperature. The rod 701 is chilled to a martensitic condition (malleable state) prior to insertion into bone, allowing for easy insertion. The rod 701 articulates to the predetermined, desired position upon returning to room temperature. This ensures that the proximal end of the cutting tip 720 attains full activation without depending on heat transfer from the distal end of the rod 701 (which is in contact with the patient) or any outside means (e.g., heat, voltage, etc.). A lumen 703 is provided in the rod 701 to facilitate the introduction of a cooling media (S), e.g., chilled saline, to deactivate the material and allow for easy withdrawal. In another alternative embodiment, the alloy is super-elastic and the cannula 104 confines the pre-bent or formed cutting tip 720 until the activation mechanism deploys the cutting tip 720 to extend beyond the cannula 104 (see FIGS. 35A and 35B). In another alternative embodiment, the rod 701 may be used to straighten the cannula 104 which is formed of a shape memory alloy. In this embodiment, the cutting tip 720 is disposed on the shape memory cannula 104 (not shown). The cannula 104 is educated to have a curved tip and the rod 701 is moveably disposed within the cannula 104 to straighten the cannula 104 by fully engaging the rod 701 within the cannula 104 (i.e. by pushing the rod 701) and to allow the cannula 104 and cutting tip 720 to curve or articulate by pulling back on the rod 701. Desirably, the rod 701 is made of a rigid material, such as stainless steel. In another embodiment, the activation temperature of the alloy is set at a temperature higher than body temperature. In this embodiment, the rod 701 is malleable for insertion and withdrawal. The rod 701 achieves full activation to its predetermined shape only through the application of heat or voltage. This permits control of the change of the state of the rod 701 from malleable to the predetermined shape, or any percentage there between, using a potentiometer or other suitable device. The rod 701 may be attached to a handle by a standard square drive or Hudson-style orthopedic fitting on the proximal end (not shown). A torque-regulating handle could be mated to the rod 701 to allow for torque-limiting rotational scraping. In one embodiment, the rod 701 is fixedly attached or otherwise coupled to a handle 18 having an actuator mechanism. For example, in the illustrated embodiment, the rod 701 is coupled to a thumbscrew 152 and is driven by an actuator mechanism similar to the mechanism illustrated in FIGS. 19 and 20. The rod 701 is actuated (moved in fore and aft directions) within the cannula 104 by the actuator mechanism. This permits the cutting tip 720 to be retracted (FIG. 26) in a malleable state within the cannula 104 for easy insertion and withdrawal and then extended (FIG. 27) beyond the distal end of the cannula 104 within bone and activated for use (FIG. 28). In a preferred embodiment, the handle 18 includes a luer fitting 705. The fitting 705 is sized and configured to mate with a complementary luer fitting 707 on a fluid introduction device, e.g., a syringe 709, to establish fluid communication between the lumen 703 and the fluid introduction device 709. Fluid, e.g., chilled or heated saline, may be introduced from the syringe 709 through the rod lumen 703 to control movement of the rod 701 between the malleable (deactivated) and activated states. In an alternative embodiment, shown in FIGS. 29 and 30, a cutting tip 720A of a desired configuration is formed at the distal end of the malleable rod 701. The tip 720A may be a separate piece welded to the rod 701, or the tip 720A may be carved or otherwise formed in the rod 701, e.g., by conventional machining techniques. In the illustrated embodiment, the cutting tip 720A is of a conical trunk and domed disc configuration similar to the embodiment illustrated in FIGS. 17 and 18. It is apparent, however, that the configuration of the cutting tip 720A can be varied according to the procedure being performed and/or to accommodate individual anatomy. In one embodiment, the entire rod 701, including the cutting tip 720A, are formed of the shape memory alloy. The rod 701 yields from a malleable state (FIG. 29) to the activated state (FIG. 30) as previously described. The rod 701 desirably includes a lumen 703 to permit introduction of a fluid media to control movement between the deactivated and activated states, as also previously described. In an alternative embodiment, illustrated in FIGS. 31 and 32, the tip 720A and a distal portion 711 of the rod 701 are formed of a shape memory alloy. A rod body 713 is formed of any suitable biocompatible, surgical grade material. The distal portion 711, carrying the cutting tip 720A, is welded or otherwise fixed to the rod body 713. The distal portion 711 of the rod 701 yields from a malleable state (FIG. 31) to the activated state (FIG. 32). The rod 701 desirably includes a lumen 703 to permit introduction of a fluid media to control movement between the deactivated and activated states. In an alternative embodiment, the rod 701 may include a dual lumen 714 so that fluid media can circulate through the shaft 112 and desirably through the cutting tip 720 (see FIG. 33) In another alternative embodiment, the rod 701 may include a throughbore703A to accommodate more thermal flow (see FIG. 34). B. Alternative Mechanical Void Creators FIG. 36 shows an alternative embodiment of a mechanical tool 400 for creating a void in an interior body region. A shaft 412 carries a sharp, stout, metal spring 420 on the end of a shaft 412. The shaft 412 can be rotated against the direction of the spring 420 causing it to cut bone (or other tissue) in an expanding fashion. The tool 400 is sized and configured to be introduced through a cannula (not shown) with the spring 420 extending beyond the cannula and the shaft 412 rotated into the tissue a short distance at a time. The shaft 412 can then be withdrawn to remove any captured tissue. If no tissue is captured, the tool 400 is reintroduced farther into the tissue and tissue removal is again attempted. The tool 400 may also be used to loosen tissue to allow better cutting and/or removal by other mechanical tools. FIG. 37 shows another embodiment of a mechanical tool 500 for creating a void in an interior body region. Two or more fingers 520 are carried on the distal end of a shaft 512. Preferably, the shaft 512 carries four fingers 520, two fingers 520 facing each other. The fingers 520 are introduced into the tissue through a cannula (not shown), and then mechanically closed with a pulley-type system or other similar system to grab tissue for extraction. Desirably, the fingers 520 are adapted to further expand as the size of the void increases. It is apparent that the length of the fingers 520 may be chosen to suit the intended use and particular individual anatomy. FIGS. 38 and 39 show another embodiment of a mechanical tool 600 for creating a void in an interior body region. The tool includes a hinged void-creating device 620 carried on the distal end of the shaft 612. The void-creating device 620 may be used to create a void or to loosen tissue to allow better cutting and removal by other mechanical tools. The void-creating device 620 provides for adjusting the height of the device 620. A positioning rod 621 is coupled to the device 620 for expanding and contracting the device 620. The height may be adjusted by drawing in the rod 621 to increase the height H and pushing out on the rod to decrease the height H of the device 620. Calibrated markings (not shown) may be provided on the rod handle to indicate the dimension of the device 620 as the rod 621 is drawn back or advanced. The height H may also be chosen to suit the intended use and particular individual anatomy. FIG. 40 shows an embodiment similar to FIGS. 35 and 36, but additionally providing a spring blade or series of spring blades 623 for more aggressive cutting. The spring blades 623 are coupled to the last blades out of the cannula and desirably pre-bent to cut parallel to the end plates. IV. Creation of Voids in Bone Two or more different mechanical cutting tools of the type described may also be used in combination to form a cavity or void of a desired size and configuration in a targeted bone. In addition, one or more mechanical cutting tools may be used in combination with one or more expandable void-creating tools to form the desired void. Expandable structures for creating voids in bones are described in U.S. Pat. Nos. 4,969,888, 5,827,289, 5,972,015, 6,235,043, 6,248,110, and 6,607,544, all of which are herein incorporated by reference. Fracture reduction and deformity correction is influenced by a variety of factors, including, but not limited to, acuteness of the fracture, bone quality (e.g. osteoporosis, bone cancers, steroid-induced osteoporosis), and healing. In some fractures, expansion of the expandable structure may be distorted by a region or regions of hard bone. This results in a high pressure within the expandable structure and low volume of expansion media within the expandable structure. The use of a mechanical cutting tool to selectively break up the region of hard bone will allow the expandable structure to achieve a more consistent and reliable fracture reduction. Mechanical cutting or scraping tools will break bone, but an expandable structure is required for the en-masse endplate reduction and deformity correction. In use, an access path to bone is made using a conventional access cannula by techniques commonly known in the art. A first void creator, which may be a mechanical cutting tool or an expandable structure, is then introduced into a bone to create a void. The first void creator is then removed. A second void creator, which may be the same as or different from the first void creator, is then inserted into the bone to enlarge or further define the void to form a void of a desired size and configuration. The second void creator is then removed. If desired, a third void creator, which may be the same or different from the first and/or second void creators, may then be introduced to further enlarge and define the void and then removed. Desirably, a filling material, e.g., bone cement or bone substitute, is then injected or otherwise introduced into the void to fill the void. In one embodiment, illustrated in FIGS. 41A-41D, a first mechanical cutting tool 800A and a second mechanical cutting tool 800B, which may be different in size and/or configuration from the first cutting tool 800A, are used to create a void 802 of a desired size and configuration. An access cannula 104 is percutaneously introduced to provide an access path into a bone, e.g., a vertebra 142 (FIG. 41A). The first mechanical cutting tool 800A is introduced through the cannula 104 into the cancellous bone 39 of the vertebra 142. The cutting tip 820A is manipulated in a series of longitudinal and/or rotational movements to create a void 802 in the cancellous bone 39 (FIG. 41B). The first cutting tool 800A is then removed. The second mechanical cutting tool 800B is then introduced and manipulated in a series of longitudinal and/or rotational movements (FIG. 41C). The second cutting tool 800B desirably has a cutting tip 820B of a different size and/or configuration to enlarge and/or otherwise further define the void 802 created by the first tool 800A. For example, in the illustrated embodiment, the second cutting tool 800B has a cutting tip 820B of a greater height than the first cutting tip 820A to enlarge the void 802, but is of a similar configuration. The second cutting tool 800B is then removed. A filler material 804, e.g., bone cement or bone substitute, may then be introduced into the void 802 to fill the void 802 (FIG. 41D). Alternatively, as shown in FIGS. 42A-42E, after removal of the second cutting tool 800B, an expandable structure 900may be introduced through the cannula 104 and expanded to enlarge and/or further define the void 802 created by the first and second mechanical cutting tools 802A and 802B. While in the illustrated embodiment the expandable structure 900 takes the form of a balloon adapted to expand or form a void by compression of cancellous bone, the expandable structure 900 may be any suitable device which can be expanded to enlarge and/or further define the void. For example, the expandable structure 900 may also be a mechanical jack, retractor, or spring. Desirably, the expandable structure 900 has a collapsed condition permitting insertion of the expandable structure 900 through the cannula 104 and an expanded condition in which the expandable structure 900 compacts cancellous bone 39 upon expansion within the cancellous bone 39. The expandable structure 900 is then removed. The void 802 may then be filled, as previously described. In another embodiment, illustrated in FIGS. 43A-43D, a first expandable structure 900A and a second expandable structure 900B, which may be different in size and/or configuration from the first expandable structure 900A, are used to create a void 802 of a desired size and configuration. An access cannula 104 is percutaneously introduced to provide an access path into a vertebra 142 (FIG. 43A). The first expandable structure 900A is introduced through the cannula 104 in the collapsed condition into the cancellous bone 39 of the vertebra 142. The expandable structure 900A is then expanded to create a void 802 in cancellous bone 39 (FIG. 43B). The first expandable structure 900A is then removed. The second expandable structure 900B is then introduced and expanded (FIG. 43C). The second expandable structure 900B is desirably of a different size and/or configuration such that expansion of the second expandable structure 900B enlarges and/or otherwise further defines the void 802 created by the first expandable structure 900A. For example, in the illustrated embodiment, the second expandable structure 900B is of a larger volume, but is of a similar configuration. It is contemplated, however, that the second expandable structure 900B may be of a different configuration than the first expandable structure 900A. The second expandable structure 900B is then removed. A filler material 804, e.g., bone cement or bone substitute, may then be introduced into the void 802 to fill the void 802 (FIG. 43D). Alternatively, as shown in FIGS. 44A-44E, after removal of the second expandable structure 900B, if desired, a mechanical cutting tool 800 may be introduced through the cannula 104 to enlarge and/or further define the void 802 created by the first and second expandable structures 900A and 900B. The cutting tool 800 is then removed. The void 802 may then be filled, as previously described. FIGS. 45A-45E illustrate another method of creating a void 802 in bone of a desired size and configuration. An access cannula 104 is percutaneously introduced to provide an access path into a vertebra 142 (FIG. 45A). A first expandable structure 900A is introduced through the cannula 104 in the collapsed condition into the cancellous bone 39 of the vertebra 142. The expandable structure 900A is then expanded to create a void 802 in cancellous bone 39 (FIG. 45B) Because the reticulum of the cancellous bone 39 may be somewhat dense, it may be difficult for the expandable structure 900A to sufficiently compact the cancellous bone 39 to permit full expansion of the expandable body 900A. This may occur with older fractures or in normal bone that has been injured by trauma, but is not necessarily osteoporotic. In this case, the expandable structure 900A may expand preferentially in a given direction depending on the density of the reticulum, but is not able to expand to its full preformed shape, as seen in FIG. 45B. The first expandable structure 900A is then removed. A mechanical cutting tool 800 is then introduced (FIG. 45C). The cutting tip 820 is manipulated in a series of longitudinal and/or rotational movements to enlarge and/or otherwise further define the void 802 created by the expandable structure 900A. The cutting tool 800 is then removed. If desired, a second expandable structure 900B, which may be of a different size and/or configuration from the first expandable structure 900A, is then introduced prior to filling the void 802 (FIG. 45D). Use of the cutting tool 800 to break or cut the reticulum and expand the void 802 allows the second expandable structure 900A to fully expand. The second expandable structure 900A is then expanded to enlarge and/or otherwise further define the previously created void 802. The second expandable structure 900B is then removed. Alternatively, instead of a second expandable structure 900B, the first expandable structure 900A may be reintroduced, re-expanded, and then removed. A filler material 804 may then be introduced into the void 802 to fill the void (FIG. 45E). In an alternative method shown in FIGS. 46A-46E, an access cannula 104 is percutaneously introduced to provide an access path into a vertebra 104 (FIG. 46A). An expandable structure 900 is introduced and expanded to create a void 802 in cancellous bone 39 (FIG. 46B) The first expandable structure 900A is then removed. A first mechanical cutting tool 800A is then introduced (FIG. 46C). The cutting tip 820A is manipulated in a series of longitudinal and/or rotational movements to enlarge and/or otherwise further define the void 802 created by the expandable structure 900. The cutting tool 800 is then removed. If desired, a second mechanical cutting tool 800B, which may be of a different size and/or configuration from the first mechanical cutting tool 800A, is then introduced prior to filling the void 802 (FIG. 46D). The cutting tip 820B is manipulated in a series of longitudinal and/or rotational movements to enlarge and/or otherwise further define the void 802 created by the expandable structure 900 and first cutting tool 800A. The second cutting tool 800B is then removed. A filler material 804 may then be introduced into the void 802 to fill the void 802 (FIG. 46E) In an alternative method shown in FIGS. 47A-47E, a first mechanical cutting tool 800A is introduced and manipulated in a series of longitudinal and/or rotational movements to create a void 802. The first cutting tool 800A is then removed. An expandable structure 900 is then introduced and expanded to enlarge and/or otherwise further define the void 802 created by the first cutting tool 800A. The expandable structure 900 is then removed. If desired, a second mechanical cutting tool 800B, which may be of a different size and/or configuration from the first mechanical cutting tool 800A, is then introduced prior to filling the void 802. The cutting tip 820B is manipulated in a series of longitudinal and/or rotational movements to enlarge and/or otherwise further define the void 802 created by the expandable structure 900A and first cutting tool 802A. The second cutting tool 802B is then removed. A filler material 804 may then be introduced into the void 802 to fill the void 802. Alternatively, as seen in FIGS. 48A-48E, instead of a second mechanical cutting tool, a second expandable structure 900B, is introduced and expanded to enlarge and/or otherwise further define the void created by the first expandable structure 900A and first cutting tool 800A. | <SOH> BACKGROUND OF THE INVENTION <EOH>A minimally invasive method of forming a cavity or void within one of the body's solid organs, for both diagnostic and treatment purposes, is becoming increasingly important as radiological and other types of scanning techniques improve a physician's ability to view inside the body without having to make an incision. The most common solid organ currently making use of a minimally invasive technique to form a void is bone. Typically this is any pathological bone in the body with a fracture, osteoporosis, or a tumor. The most commonly used void-forming method for bones is the inflatable bone tamp, as described in U.S. Pat. Nos. 4,969,888 and 5,108,404. Void formation in this case is usually followed by filling with a filling substance like bone cement or a bone substitute. Mechanical methods are also available for making voids inside solid organs. Those solid organs include the brain, the kidneys, the spleen, the liver and bone. In the brain, for example, an abscess could be easily debrided and irrigated with a minimally invasive mechanical void technique. A fractured spleen could be approached with a minimally invasive technique, to make a small void to fill with gelfoam or some other coagulant to stop hemorrhage. An osteoporotic, fractured vertebral body or bone tumor could be approached by a minimally invasive mechanical system in order to create a cavity or void and then refill with a bone substitute. A demand exists for systems or methods that are capable of forming voids in bone and other interior body regions in safe and efficacious ways. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention provides systems and methods for creating voids in interior body regions. One aspect of the invention provides a cutting tip for cutting or scraping bone. In one embodiment, a curette-type instrument at the end of a shaft can be mechanically angled into different positions to scrape material to form a void. In another embodiment, a mechanical device at the end of a shaft resembles a T-type configuration and allows both translational and rotational cutting to form a void. In a third embodiment, the cutting tip includes a turned and tapered trunk. In a fourth embodiment, the cutting tip includes a conical trunk. In a fifth embodiment, a sharp, stout, metal spring is provided on the end of a shaft. In a sixth embodiment, the distal end of a shaft carries two or more fingers to grab tissue for extraction. In a seventh embodiment, a hinged void-forming device is carried by a shaft and allows for formation of a void, which may be of a rectangular or any other pre-determined shape. Another aspect of the invention provides an actuator mechanism for deploying a cutting tip. In one embodiment, rotational movement of a thumbwheel is converted to translational movement of a plunger rod. In an alternative embodiment, rotational movement of a control knob is converted to translational movement of a plunger rod through interaction of a series of gears. Another aspect of the invention provides a tool for creating voids in interior body regions. The tool comprises a shaft, a tip for contacting bone, and a hinge member coupling the tip to the shaft. The tip becomes uncoupled if the torque applied exceeds a maximum hinge torque. The shaft includes a region of weakness proximal to the tip along which the shaft will break if the torque applied exceeds a maximum shaft torque. The maximum hinge torque is greater than the maximum shaft torque. According to another aspect of the invention, a tool for creating voids in interior body regions comprises a shaft assembly including a lumen, a tip for contacting bone coupled to the shaft, and a rod slidable within the lumen. The rod is tethered to the tip. According to another aspect of the invention, a tool for creating voids in interior body regions comprises a shaft including a lumen, and a tip for contacting bone coupled to the shaft by a coupling element. The tip is additionally tethered to the shaft such that the tip remains tethered to the shaft if the coupling element becomes inoperable. According to another aspect of the invention, a tool for creating voids in interior body regions comprises a cannula and a shaft. The shaft has a handle and is sized and configured for passage through the cannula. A projection extends radially from the shaft to restrict forward advancement of the shaft within the cannula. Another aspect of the invention provides methods of creating a void in bone. The methods provide one or more mechanical cutting tools that may be used in combination with one or more expandable void-creating structures to form a void of a desired size and configuration. | 20040716 | 20050802 | 20050526 | 95675.0 | 1 | REIP, DAVID OWEN | DEVICES FOR CREATING VOIDS IN INTERIOR BODY REGIONS AND RELATED METHODS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,892,828 | ACCEPTED | Steroid derived antibiotics | A series of novel steroid derivatives are described. The steroid derivatives are antibacterial agents. The steroid derivatives also act to sensitize bacteria to other antibiotics including erythromycin and novobiocin. | 1. A compound according to formula I wherein: fused rings A, B, C, and D are independently saturated or fully or partially unsaturated; and R1 through R4, R6, R7, R11, R12, R15, R16, and R17 is each independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and R5, R8, R9, R10, R13, and R14 is each independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)—C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and provided that at least two of R1 through R14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof. 2. The compound of claim 1, wherein at least one of the following pairs is deleted and the valency of the ring carbon atoms at these deleted positions is completed with a double bond: R5, and R9; R8 and R10; and R13 and R14. 3. The compound of claim 1, wherein at least three of R1 through R14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, (C1-C10) quaternaryammoniumalkylcarboxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy. 4. The compound of claim 3, wherein the 3 of R1 through R14 independently selected from the group consisting of a substituted or unsubstituted (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, and (C1-C10) quaternaryammoniumalkylcarboxy. 5. The compound of claim 1, wherein the second steroid is a compound of formula I. 6. The compound of claim 1, wherein the linking group is (C1-C10) alkyl-oxy-(C1-C10) alkyl. 7. The compound of claim 1, wherein none of R5, R8, R9, R13, and R14 is deleted. 8. The compound of claim 1, wherein each of R3, R7, and R12 is independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkylcarboxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group or a pharmaceutically acceptable salt thereof. 9. The compound of claim 8, wherein R1, R2, R4, R5, R6, R8, R10, R11, R13, R14, R15, and R16 are hydrogen. 10. The compound of claim 9, wherein R17 is —CR18R19R20, where each of R18, R19, and R20, is independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, (C1-C10) haloalkyl, (C2-C6) alkenyl, (C2-C6) alkynyl, oxo, and a linking group attached to a second steroid. 11. The compound of claim 8, wherein each of R3, R7, and R12, is independently selected from the group consisting of —O—(CH2)n-NH2, —O—CO—(CH2)n-NH2, —O—(CH2)n-NH—C(NH)—NH2, —O—(CH2)n-N3, —O—(CH2)n-CN, where n is 1 to 3, and —O—C(O)—HC(Q5)-NH2, where Q5 is a side chain of any amino acid. 12. The compound of claim 8, wherein each of R3, R7, and R12, is —O—CO—(CH2)n-NH2, where n is 1 to 4. 13. The compound of claim 12, wherein R17 is —CH(CH3)(CH2)3—O—(CH2)n—NH2, wherein n is 1-7. 14. The compound of claim 12, wherein R17 is —CH(CH3)—(CH2)n—NR1R2, wherein n is 0-2, R1 and R2 are independently (C1-C6) alkyl, aryl or aralkyl. 15. The compound of claim 1, wherein R17 is —CH(CH3)(CH2)n1—CO—OR3, where R3 is selected from —CH2)n2N+(CH3)3, wherein n1 and n2 are independently 1-4. 16. The compound of claim 15, wherein R3, R7, and R12 are —O—C(O)—(CH2)n—NH2, wherein n is 1-5. 17. The compound of claim 1 having the following formula: wherein n is 1-3, and Bn is a benzyl group. 18. The compound of claim 1 having the following formula: wherein n is 1-3, and R is selected from n-octyl, and trimethylethylammonio. 19. The compound of claim 1 having the formula: 20. A method of preparing the compound according to formula I wherein fused rings A, B, C, and D are independently saturated or fully or partially unsaturated; and R1 through R4, R6, R7, R11, R12, R15, R16, and R17 is each independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and R5, R8, R9, R10, R13, and R14 is each independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)—C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and provided that at least two of R1 through R14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)—C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof; the method comprising contacting a compound of formula IV, where at least two of R1 through R are hydroxyl, and the remaining moieties on the fused rings A, B, C, and D are defined for formula I, with an electrophile to produce an alkyl ether compound of formula IV, wherein at least two of R1 through R14 are (C1-C10)alkyloxy; converting the alkyl ether compounds into an amino precursor compound wherein at least two of R1 through R14 are independently selected from the group consisting of (C1-C10) azidoalkyloxy and (C1-C10) cyanoalkyloxy; and reducing the amino precursor compound to form a compound of formula I. 21. The method of claim 20, wherein the electrophile is allylbromide. 22. A method of producing a compound of formula I: wherein fused rings A, B, C, and D are independently saturated or fully or partially unsaturated; and R1 through R4, R6, R7, R11, R12, R15, R16, and R17 is each independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and R5, R8, R9, R10, R13, and R14 is each independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and provided that at least two of R1 through R14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof; the method comprising contacting a compound of formula IV, where at least two of R1 through R14 are hydroxyl, and the remaining moieties on the fused rings A, B, C, and D are defined for formula I, with an electrophile to produce an alkyl ether compound of formula IV, wherein at least two of R1 through R14 are (C1-C10) alkyloxy; converting the alkyl ether compound into an amino precursor compound wherein at least two of R1 through R14 are independently selected from the group consisting of (C1-C10) azidoalkyloxy and (C1-C10) cyanoalkyloxy; reducing the amino precursor compound to produce an aminoalkyl ether compound wherein at least two of R1 through R14 are (C1-C10) aminoalkyloxy; and contacting the aminoalkyl ether compound with a guanidino producing electrophile to form a compound of formula I. 23. The method of claim 22, wherein the guanidino producing electrophile is HSO3—C(NH)—NH2. 24. A pharmaceutical composition comprising an effective amount of a compound of claim 1. 25. The pharmaceutical composition of claim 24, wherein the composition includes additional antibiotics. 26. A method of treating a microbial infection of a host by administering to the host an effective amount of an anti-microbial composition comprising a compound according to claim 1. 27. The method of claim 26 wherein the host is a human. 28. The method of claim 26 wherein the anti-microbial composition further comprises a second anti-microbial substance to be delivered into a microbial cell. 29. The method of claim 28 wherein the second anti-microbial substance is an antibiotic. 30. The method of claim 26 wherein the infection is a bacterial infection. 31. The method of claim 30 wherein the infection is a infection a Gram-negative bacterial infection. 32. The method of claim 30 wherein the bacterial infection is an infection with a bacterium characterized by an outer membrane comprising a substantial percentage of lipid A. 33. A method of enhancing cell permeability by administering to the cell a permeability-enhancing amount of the compound of claim 1. 34. The method of claim 33 further comprising administering to the cell a substance to be introduced into the cell. 35. The method of claim 34 in which the cell is a bacterium. 36. The method of claim 35 in which the bacterium is a Gram-negative bacterium. 37. The method of claim 34 in which the cell is a sperm cell and the compound is part of a spermicidal composition. 38. A method of identifying compounds effective against a microbe comprising administering a candidate compound and a compound according to claim 1 to the microbe and determining whether the candidate compound has a static or toxic effect on the microbe. 39. The method of claim 38 in which the microbe is a Gram-negative bacterium. 40. A method of microbial growth control comprising contacting a microbe with an effective amount of anti-microbial composition comprising a compound according to claim 1. 41. A composition of matter comprising the compound of claim 1 in combination with an anti-microbial substance to be introduced into a cell. 42. A compound comprising a ring system of at least 4 fused rings, each of the rings having from 5-7 atoms, the ring system having two faces, wherein the compound comprises 3 chains attached to the same face of the ring system, each of the chains containing a multiple nitrogen-containing group, wherein the multiple nitrogen-containing group is separated from the ring system by at least one atom, and wherein the multiple nitrogen-containing group is a (C1-C10) alkylamino (C1-C10) alkyamino group or a (C1-C10) alkylamino (C1-C10) alkyamino (C1-C10) alkyamino group. 43. The compound of claim 42, wherein each of the mulitiple nitrogen-containing groups is separated from the steroid backbone by at least two atoms. 44. The compound of claim 43, wherein each of the multiple nitrogen-containing groups is separated from the steroid backbone by at least three atoms. 45. The compound of claim 44, wherein each of the multiple nitrogen-containing groups is separated from the steroid backbone by at least four atoms. 46. The compound of claim 42, wherein the compound further comprises a hydrophobic group attached to the steroid backbone. 47. The compound of claim 42, wherein the hydrophobic group is selected from the group consisting of a substituted (C3-10) aminoalkyl group, a (C1-10) alkyloxy (C3-10) alkyl group, and a (C1-10) alkylamino (C3-10)alkyl group. 48. A pharmaceutical composition comprising an effective amount of a compound of claim 42. 49. A method of enhancing cell permeability by administering to the cell a permeability enhancing amount of the compound of claim 42. 50. A compound of claim 1 having the formula: wherein R1 is selected from hydrogen, or (C1-C10) alkylamino, R2 is selected from (C1-C10) alkylamino or (C1-C10) alkylamino-(C1-C10) alkylamino, and n is 1-3. 51. The compound of claim 1, wherein R1 is hydrogen and R2 is (C1-C10) alkylamino-(C1-C10) alkylamino. 52. The compound of claim 1, wherein R1 is (C1-C10) alkylamino, and R2 is (C1-C10) alkylamino. 53. A compound according to formula I wherein: fused rings A, B, C, and D are independently saturated or fully or partially unsaturated; and R1 through R4, R6, R7, R11, R12, R15, and R16, is each independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and R5, R8, R9, R10, R13, and R14 is each independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and R17 is selected from the group consisting of substituted or unsubsituted alkylcarboxyalkyl and protected or unprotected poly(aminoalkyl), provided that at least two of R1 through R14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof. 54. The compound of claim 53, wherein the compound has the formula: wherein n is 1-3. 55. The compound of claim 53, wherein the compound has the formula: wherein n is 1-3. 56. Canceled. 57. Canceled. 58. Canceled. | CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of U.S. patent application Ser. No. 09/234,008, filed Jan. 19, 1999, which is a continuation-in-part of PCT/US 98/04489, filed Mar. 6, 1998, each of which is hereby incorporated by reference in its entirety. This application claims priority from provisional application U.S. 60/225,467, filed Aug. 15, 2000, which is hereby incorporated by reference in its entirety. STATEMENT OF GOVERNMENT INTEREST This invention was made with support from the National Institutes of Health (GM 54619). The government has certain rights in this invention. BACKGROUND OF THE INVENTION The invention relates to novel steroid derivatives and processes and intermediates for the preparation of these compounds. Some compounds that associate strongly with the outer membrane of Gram-negative bacteria are known to disrupt the outer membrane and increase permeability. The increased permeability can increase the susceptibility of Gram-negative bacteria to other antibiotics. The best studied of this type of compound are the polymyxin antibiotics. For an example of a study involving the binding of polymyxin B to the primary constituent of the outer membrane of Gram-negative bacteria (lipid A) see: D. C. Morrison and D. M. Jacobs, Binding of Polymyxin B to The Lipid a Portion of Bacterial Lipopolysaccharides, Immunochemistry 1976, vol. 13, 813-819. For an example of a study involving the binding of a polymyxin derivative to Gram-negative bacteria see: M. Vaara and P. Viljanen, Binding of Polymyxin B Nonapeptide to Gram-negative Bacteria, Antimicrobial Agents and Chemotherapy, 1985, vol. 27, 548-554. Membranes of Gram-negative bacteria are semipermeable molecular “sieves” which restrict access of antibiotics and host defense molecules to their targets within the bacterial cell. Thus, cations and polycations which interact with and break down the outer membrane permeability barrier are capable of increasing the susceptibility of Gram-negative pathogenic bacteria to antibiotics and host defense molecules. Hancock and Wong demonstrated that a broad range of peptides could overcome the permeability barrier and coined the name “permeabilizers” to describe them (Hancock and Wong, Antimicrob. Agents Chemother., 26:48, 1984). SUMMARY OF THE INVENTION The present invention features compounds of the formula I wherein: fused rings A, B, C, and D are independently saturated or fully or partially unsaturated; and each of R1 through R4, R6, R7, R11, R12, R15, R16, and R17 is independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—C(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid (including the side chain of glycine, i.e., H), P.G. is an amino protecting group, and R5, R8, R9, R10, R13, and R14 is each independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and provided that at least two of R1 through R14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof. The term fused ring used herein can be heterocyclic or carbocyclic, preferably. The term “saturated” used herein refers to the fused ring of formula I having each atom in the fused ring either hydrogenated or substituted such that the valency of each atom is filled. The term “unsaturated” used herein refers to the fused ring of formula I where the valency of each atom of the fused ring may not be filled with hydrogen or other substituents. For example, adjacent carbon atoms in the fused ring can be doubly bound to each other. Unsaturation can also include deleting at least one of the following pairs and completing the valency of the ring carbon atoms at these deleted positions with a double bond; such as R5 and R9; R8 and R10; and R13 and R14. The term “unsubstituted” used herein refers to a moiety having each atom hydrogenated such that the valency of each atom is filled. The term “halo” used herein refers to a halogen atom such as fluorine, chlorine, 0.10 bromine, or iodine. Examples of amino acid side chains include but are not limited to H (glycine), methyl (alanine), —CH2—(C═O)—NH2 (asparagine), —CH2—SH (cysteine), and —CH(OH)CH3 (threonine). An alkyl group is a branched or unbranched hydrocarbon that may be substituted or unsubstituted. Examples of branched alkyl groups include isopropyl, sec-butyl, isobutyl, tert-butyl, sec-pentyl, isopentyl, tert-pentyl, isohexyl. Substituted alkyl groups may have one, two, three or more substituents, which may be the same or different, each replacing a hydrogen atom. Substituents are halogen (e.g., F, Cl, Br, and I), hydroxyl, protected hydroxyl, amino, protected amino, carboxy, protected carboxy, cyano, methylsulfonylamino, alkoxy, acyloxy, nitro, and lower haloalkyl. The term “substitued” used herein refers to moieties having one, two, three or more substituents, which may be the same or different, each replacing a hydrogen atom. Examples of substituents include but are not limited to halogen (e.g., F, Cl, Br, and I), hydroxyl, protected hydroxyl, amino, protected amino, carboxy, protected carboxy, cyano, methylsulfonylamino, alkoxy, alkyl, aryl, aralkyl, acyloxy, nitro, and lower haloalkyl. An aryl group is a C6-20 aromatic ring, wherein the ring is made of carbon atoms (e.g., C6-14, C6-10 aryl groups). Examples of haloalkyl include fluoromethyl, dichloromethyl, trifluoromethyl, 1,1-difluoroethyl, and 2,2-dibromoethyl. An aralkyl group is a group containing 6-20 carbon atoms that has at least one aryl ring and at least one alkyl or alkylene chain connected to that ring. An example of an aralkyl group is a benzyl group. A linking group is any divalent moiety used to link a compound of formula to another steroid, e.g., a second compound of formula I. An example of a linking group is (C1-C10) alkyloxy-(C1-C10) alkyl. Numerous amino-protecting groups are well-known to those in the art. In general, the species of protecting group is not critical, provided that it is stable to the conditions of any subsequent reaction(s) on other positions of the compound and can be removed at the appropriate point without adversely affecting the remainder of the molecule. In addition, a protecting group may be substituted for another after substantive synthetic transformations are complete. Clearly, where a compound differs from a compound disclosed herein only in that one or more protecting groups of the disclosed compound has been substituted with a different protecting group, that compound is within the invention. Further examples and conditions are found in T. W. Greene, Protective Groups in Organic Chemistry, (1st ed., 1981, 2nd ed., 1991). The present invention also includes methods of synthesizing compounds of formula I where at least two of R1 through R14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy. The method includes the step of contacting a compound of formula IV, where at least two of R1 through R14 are hydroxyl, and the remaining moieties on the fused rings A, B, C, and D are defined for formula I, with an electrophile to produce an alkyl ether compound of formula IV, wherein at least two of R1 through R14 are (C1-C10)alkyloxy. The alkyl ether compounds are converted into an amino precursor compound wherein at least two of R1 through R14 are independently selected from the group consisting of (C1-C10) azidoalkyloxy and (C1-C10) cyanoalkyloxy and the amino precursor compound is reduced to form a compound of formula I. The electrophiles used in the method include but are not limited to 2-(2-bromoethyl)-1,3-dioxolane, 2-iodoacetamide, 2-chloroacetamide, N-(2-bromoethyl)phthalimide, N-(3-bromopropyl)phthalimide, and allybromide. The preferred electrophile is allylbromide. The invention also includes a method of producing a compound of formula I where at least two of R1 through R14 are (C1-C10) guanidoalkyloxy. The method includes contacting a compound of formula IV, where at least two of R1 through R14 are hydroxyl, with an electrophile to produce an alkyl ether compound of formula IV, where at least two of R1 through R14 are (C1-C10)alkyloxy. The allyl ether compound is converted into an amino precursor compound where at least two of R1 through R14 are independently selected from the group consisting of (C1-C10) azidoalkyloxy and (C1-C10) cyanoalkyloxy. The amino precursor compound is reduced to produce an aminoalkyl ether compound wherein at least two of R1 through R14 are (C1-C10) aminoalkyloxy. The aminoalkyl ether compound is contacted with a guanidino producing electrophile to form a compound of formula I. The term “guanidino producing electrophile” used herein refers to an electrophile used to produce a guanidino compound of formula I. An example of an guanidino producing electrophile is HSO3—C(NH)—NH2. The invention also includes a method of producing a compound of formula I where at least two of R1 through R14 are H2N—HC(Q5)-C(O)—O— and Q5 is the side chain of any amino acid. The method includes the step of contacting a compound of formula IV, where at least two of R1 through R14 are hydroxyl, with a protected amino acid to produce a protected amino acid compound of formula IV where at least two of at least two of R1 through R14 are P.G.-HN—HC(Q5)-C(O)—O— and Q5 is the side chain of any amino acid and P.G. is an amino protecting group. The protecting group of the protected amino acid compound is removed to form a compound of formula I. The present invention also includes pharmaceutical compositions of matter that are useful as antibacterial agents, sensitizers of bacteria to other antibiotics and disrupters of bacterial membranes. The pharmaceutical compositions can be used to treat humans and animals having a bacterial infection. The pharmaceutical compositions can include an effective amount of the steroid derivative alone or in combination with other antibacterial agents. The invention further includes a method of preparing the compound (A): by (a) contacting 5β-cholanic acid 3,7,12-trione methyl ester with hydroxylamine hydrochloride and sodium acetate to form the trioxime (B): (b) contacting trioxime (B) with NaBH4 and TiCl4 to yield compound (A). The invention also includes a compound comprising a ring system of at least 4 fused rings, where each of the rings has from 5-7 atoms. The ring system has two faces, and contains 3 chains attached to the same face. Each of the chains contains a nitrogen-containing group that is separated from the ring system by at least one atom; the nitrogen-containing group is an amino group, e.g., a primary amino group, or a guanidino group. Preferably, the compound also contains a hydrophobic group, such as a substituted (C3-10) aminoalkyl group, a (C1-10) alkyloxy (C3-10) alkyl group, or a (C1-10) alkylamino (C3-10)alkyl group, attached to the steroid backbone. For example, the compound may have the formula V, where each of the three chains containing nitrogen-containing groups is independently selected from R1 through R4, R6, R7, R11, R12, R15, R16, R17, and R18, defined below. where: each of fused rings A, B, C, and D is independently saturated, or is fully or partially unsaturated, provided that at least two of A, B, C, and D are saturated, wherein rings A, B, C, and D form a ring system; each of m, n, p, and q is independently 0 or 1; each of R1 through R4, R6, R7, R11, R12, R15, R16, R17, and R18 is independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid (including the side chain of glycine, i.e., H), P.G. is an amino protecting group; and each of R5, R8, R9, R10, R13, and R14 is independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, provided that at least three of R1 through R4, R6, R7, R11, R12, R15, R16, R17, and R18 are disposed on the same face of the ring system and are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof. Preferably, at least two, or at least, three, of m, n, p, and q are 1. Without wishing to be bound to any particular theory, the steroid derivatives described herein act as bacteriostatic and bactericidal agents by binding to the outer cellular membrane of bacteria. The interaction between the steroid derivatives and the bacteria membrane disrupts the integrity of the cellular membrane and results in the death of the bacteria cell. In addition, compounds of the present invention also act to sensitize bacteria to other antibiotics; At concentrations of the steroid derivatives below the corresponding minimum bacteriostatic concentration, the derivatives cause bacteria to become more susceptible to other antibiotics by increasing the permeability of the outer membrane of the bacteria. Measurements used to quantitate the effects of the steroid derivatives on bacteria include: measurement of minimum inhibitory concentrations (MICs), measurement of minimum bactericidal concentrations (MBCs) and the ability of the steroid derivatives to lower the MICs of other antibiotics, e.g., erythromycin and novobiocin. A person of skill will recognize that the compounds described herein preserve certain stereochemical and electronic characteristics found in steroids. The term “same configuration” as used herein refers to substituents on the fused steroid having the same stereochemical orientation. For example substituents R3, R7 and R12 are all β-substituted or α-substituted. The configuration of the moieties R3, R7, and R12 substituted on C3, C7, and C12 may be important for interaction with the cellular membrane. In another aspect, the invention features several methods of using the above-described compounds. For example, an effective amount of an anti-microbial composition comprising such a compound is administered to a host (including a human host) to treat a microbial infection. The compound by itself may provide the anti-microbial effect, in which case the amount of the compound administered is sufficient to be anti-microbial. Alternatively, an additional anti-microbial substance to be delivered to the microbial cells (e.g., an antibiotic) is included in the anti-microbial composition. By facilitating delivery to the target cells, the compounds can enhance the effectiveness of the additional antimicrobial substance. In some cases the enhancement may be substantial. Particularly important target microbes are bacteria (e.g., Gram-negative bacteria generally or bacteria which have a substantial (>40%) amount of a lipid A or lipid A-like substance in the outer membrane). Other microbes including fungi, viruses, and yeast may also be the target organisms. The compounds can also be administered in other contexts to enhance cell permeability to introduce any of a large number of different kinds of substances into a cell, particularly the bacterial cells discussed above. In addition to introducing anti-microbial substances, the invention may be used to introduce other substances such as macromolecules (e.g., vector-less DNA). The invention can also be used to make anti-microbial compositions (e.g., disinfectants, antiseptics, antibiotics etc.) which comprise one of the above compounds. These compositions are not limited to pharmaceuticals, and they may be used topically or in non-therapeutic contexts to control microbial (particularly bacterial) growth. For example, they may be used in applications that kill or control microbes on contact. In yet another aspect, the invention generally features methods of identifying compounds that are effective against a microbe by administering a candidate compound and a compound according to the invention the microbe and determining whether the candidate compound has a static or toxic effect (e.g, an antiseptic, germicidal, disinfectant, or antibiotic effect) on the microbe. Again, bacteria such as those discussed above are preferred. This aspect of the invention permits useful testing of an extremely broad range of candidate anti-microbials which are known to have anti-microbial effect in some contexts, but which have not yet been shown to have any effect against certain classes of microbes such as the bacteria discussed above. As described in greater detail below, this aspect of the invention permits testing of a broad range of antibiotics currently thought to be ineffective against Gram-negative or lipid A-like containing bacteria. In yet another aspect the invention features compositions which include one of the above compounds in combination with a substance to be introduced into a cell such as an antimicrobial substance as described in greater detail above. The compound and the additional substance may be mixed with a pharmaceutically acceptable carrier. Other features or advantages of the present invention will be apparent from the following detailed description of several embodiments, and also from the appending claims. The invention encompasses steroid derivatives that can be made by the synthetic routes described herein, and methods of treating a subject having a condition mediated by a bacterial infection by administering an effective amount of a pharmaceutical composition containing a compound disclosed herein to the subject. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing showing compounds of the invention. FIG. 2 is a graph showing the concentrations of compounds of the invention required to lower the MIC of erythromycin to 1 μg/ml, as well as MIC and MBC values of each of the compounds. FIG. 3 is a scheme showing the proposed mechanism of action of cholic acid derivatives. FIG. 4 is a drawing showing compounds of the invention. FIG. 5 is a graph showing MIC and MBC values for compounds of the invention. FIG. 6 is a graph showing MIC values for compounds of the invention. FIG. 7 is a drawing showing compound 132. FIG. 8 is a drawing showing compound 211. FIG. 9 is a drawing showing compounds 352-354. FIG. 10 is a drawing showing compound 355. FIG. 11 is a drawing showing compounds 341-343 and 324-327. FIG. 12 is a drawing showing compounds 356-358. DETAILED DESCRIPTION In general, the present invention provides the compounds of formula I described above. The preparation methods and the MIC and MBC of compounds of formula I are described. The cellular membrane permeability is also measured and described. Compounds that are useful in accordance with the invention, as described below, include novel steroid derivatives that exhibit bacteriostatic, bactericidal, and bacterial sensitizer properties. Those skilled in the art will appreciate that the invention extends to other compounds within the formulae given in the claims below, having the described characteristics. These characteristics can be determined for each test compound using the assays detailed below and elsewhere in the literature. Known compounds that are used in accordance with the invention and precursors to novel compounds according to the invention can be purchased, e.g., from Sigma Chemical Co., St. Louis; Aldrich, Milwaukee; Steroids and Research Plus. Other compounds according to the invention can be synthesized according to known methods and the methods described below using publicly available precursors. The compounds of the present invention include but are not limited to compounds having amine or guanidine groups covalently tethered to a steroid backbone, e.g., cholic acid. Other ring systems can also be used, e.g., 5-member fused rings. Compounds with backbones having a combination of 5- and 6-membered rings are also included in the invention. The amine or guanidine groups are separated from the backbone by at least one atom, and preferably are separated by at least two, three, or four atoms. The backbone can be used to orient the amine or guanidine groups on one face, or plane, of the steroid. For example, a scheme showing a compound having primary amino groups on one face, or plane, of a backbone is shown below: The biological activity of the compounds can be determined by standard methods known to those of skill in the art, such as the “minimal inhibitory concentration (MIC)” assay described in the present examples, whereby the lowest concentration at which no change in optical density (OD) is observed for a given period of time is recorded as MIC. When the compound alone is tested against a control that lacks the compound, the antimicrobial effect of the compound alone is determined. Alternatively, “fractional inhibitory concentration (FIC)” is also useful for determination of synergy between the compounds of the invention, or the compounds in combination with known antibiotics. FICs can be performed by checkerboard titrations of compounds in one dimension of a microtiter plate, and of antibiotics in the other dimension, for example. The FIC is calculated by looking at the impact of one antibiotic on the MIC of the other and vice versa. An FIC of one indicates that the influence of the compounds is additive and an FIC of less than one indicates synergy. Preferably, an FIC of less than 0.5 is obtained for synergism. As used herein, FIC can be-determined as follows: FIC = MIC ( compound in combination ) MIC ( compound alone ) + MIC ( antibiotic in combination ) MIC ( antibiotic alone ) This procedure permits determination of synergistic effects of the compound with other compounds. For example, substances that generally may not be sufficiently effective against certain bacteria at safe dosages can be made more effective with the compound of the invention, thus enabling use of the substances against new categories of infections. Specifically, many existing antibiotics are effective against some Gram-positive bacteria, but are not currently indicated to treat Gram-negative bacterial infection. In some cases, the antibiotic may be ineffective by itself against Gram-negative bacteria because it fails to enter the cell. Compounds of the invention may increase permeability so as to render the antibiotics effective against Gram-negative bacteria. In addition, fractional inhibitory concentration is also useful for determination of synergy between compounds of the invention in combination with other compounds having unknown anti-bacterial activity or in combination with other compounds, e.g., compounds which have been tested and show anti-bacterial activity. For example, compounds of the invention may increase permeability so as to render compounds lacking anti-bacterial activity effective against bacteria. The FIC can also be used to test for other types of previously unappreciated activity of substances that will be introduced into the cell by means of permeability enhancing compounds according to the invention. While we do not wish to be bound to any single specific theory, and such a theory is not necessary to practice the invention, one mechanism of action is the lipid A interaction of multiple (usually three) moieties, which under physiological conditions are positively charged, e.g., guanidino or amino moieties. The moieties extend away from the general plane of the remainder of the molecule, thus mimicking certain aspects of the structure of polymyxins. In this regard, compounds of the invention will generally be useful in the way that polymyxins are useful. For example, polymyxin B (PMB) and polymyxin B nonapeptide (PMBN) are useful for permeabilizing bacterial membranes. Moreover, in regard to systemic administration, those skilled in the art will recognize appropriate toxicity screens that permit selection of compounds that are not toxic at dosages that enhance microbial permeability. As noted, the invention also involves topical as well as non-therapeutic (antiseptic, germicidal, or disinfecting) applications in which the compounds are contacted with surfaces to be treated. The term “contacting” preferably refers to exposing the bacteria to the compound so that the compound can effectively inhibit, kill, or lyse bacteria, bind endotoxin (LPS), or permeabilize Gram-negative bacterial outer membranes. Contacting may be in vitro, for example by adding the compound to a bacterial culture to test for susceptibility of the bacteria to the compound. Contacting may be in vivo, for example administering the compound to a subject with a bacterial disorder, such as septic shock. “Inhibiting” or “inhibiting effective amount” refers to the amount of compound which is required to cause a bacteriostatic or bactericidal effect. Examples of bacteria which may be inhibited include E. coli, P. aeruginosa, E. cloacae, S. typhimurium, M. tuberculosis and S. aureus. In addition, the compounds of the invention can be used to inhibit antibiotic-resistant strains of microorganisms. The method of inhibiting the growth of bacteria may further include the addition of antibiotics for combination or synergistic therapy. The appropriate antibiotic administered will typically depend on the susceptibility of the bacteria such as whether the bacteria is Gram-negative or Gram-positive, and will be easily discernable by one of skill in the art. Examples of particular classes of antibiotics to be tested for synergistic therapy with the compounds of the invention (as described above) include aminoglycosides (e.g., tobramycin), penicillins (e.g., piperacillin), cephalosporins (e.g., ceftazidime), fluoroquinolones (e.g., ciprofloxacin), carbepenems (e.g., imipenem), tetracyclines and macrolides (e.g., erythromycin and clarithromycin). The method of inhibiting the growth of bacteria may further include the addition of antibiotics for combination or synergistic therapy. The appropriate antibiotic administered will typically depend on the susceptibility of the bacteria such as whether the bacteria is Gram-negative or Gram-positive, and will be easily discernable by one of skill in the art. Further to the antibiotics listed above, typical antibiotics include aminoglycosides (amikacin, gentamicin, kanamycin, netilmicin, tobramycin, streptomycin, azithromycin, clarithromycin, erythromycin, erythromycin estolate/ethylsuccinate, gluceptate/lactobionate/stearate, beta-lactams such as penicillins (e.g., penicillin G, penicillin V, methicillin, nafcillin, oxacillin, cloxacillin, dicloxacillin, ampicillin, amoxicillin, ticarcillin, carbenicillin, mezlocillin, azlocillin and piperacillin), or cephalosporins (e.g., cephalothin, cefazolin, cefaclor, cefamandole, cefoxitin, cefuroxime, cefonicid, cefinetazole, cefotetan, cefprozil, loracarbef, cefetamet, cefoperazone, cefotaxime, ceftizoxime, ceftriaxone, ceftazidime, cefepime, cefixime, cefpodoxime, and cefsulodin). Other classes of antibiotics include carbapenems (e.g., imipenem), monobactams (e.g., aztreonam), quinolones (e.g., fleroxacin, nalidixic acid, norfloxacin, ciprofloxacin, ofloxacin, enoxacin, lomefloxacin and cinoxacin), tetracyclines (e.g., doxycycline, minocycline, tetracycline), and glycopeptides (e.g., vancomycin, teicoplanin), for example. Other antibiotics include chloramphenicol, clindamycin, trimethoprim, sulfamethoxazole, nitrofurantoin, rifampin and mupirocin, and polymyxins, such as PMB. Administration The compounds may be administered to any host, including a human or non-human animal, in an amount effective to inhibit not only growth of a bacterium, but also a virus or fungus. These compounds are useful as antimicrobial agents, antiviral agents, and antifingal agents. The compounds may be administered to any host, including a human or non-human animal, in an amount effective to inhibit not only growth of a bacterium, but also a virus or fungus. These compounds are useful as antimicrobial agents, antiviral agents, and antifingal agents. The compounds of the invention can be administered parenterally by injection or by gradual infusion over time. The compounds can be administered topically, intravenously, intraperitoneally, intramuscularly, subcutaneously, intracavity, or transdermally. Preferred methods for delivery of the compound include orally, by encapsulation in microspheres or proteinoids, by aerosol delivery to the lungs, or transdermally by iontophoresis or transdermal electroporation. Other methods of administration will be known to those skilled in the art. Preparations for parenteral administration of a compound of the invention include sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media. Parenteral vehicles include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's, or fixed oils. Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers (such as those based on Ringer's dextrose), and the like. Preservatives and other additives may also be present such as, for example, antimicrobials, anti-oxidants, chelating agents, and inert gases and the like. The invention provides a method of treating or ameliorating an endotoxemia or septic shock (sepsis) associated disorder, or one or more of the symptoms of sepsis comprising administering to a subject displaying symptoms of sepsis or at risk for developing sepsis, a therapeutically effective amount of a compound of the invention. The term “ameliorate” refers to a decrease or lessening of the symptoms of the disorder being treated. Such symptoms which may be ameliorated include those associated with a transient increase in the blood level of TNF, such as fever, hypotension, neutropenia, leukopenia, thrombocytopenia, disseminated intravascular coagulation, adult respiratory distress syndrome, shock and multiple organ failure. Patients who require such treatment include those at risk for or those suffering from toxemia, such as endotoxemia resulting from a Gram-negative bacterial infection, venom poisoning, or hepatic failure, for example. In addition, patients having a Gram-positive bacterial, viral or fungal infection may display symptoms of sepsis and may benefit from such a therapeutic method as described herein. Those patients who are more particularly able to benefit from the method of the invention are those suffering from infection by E. coli, Haemophilus influenza B, Neisseria meningitidis, staphylococci, or pneumococci. Patients at risk for sepsis include those suffering from gunshot wounds, renal or hepatic failure, trauma, burns, immunocompromised (HIV), hematopoietic neoplasias, multiple myeloma, Castleman's disease or cardiac myxoma. In addition, the compounds may be incorporated into biodegradable polymers allowing for sustained release, the polymers being implanted in the vicinity of where delivery is desired, for example, at the site of a bacterial infection. The biodegradable polymers and their use are described in detail in Brem et al., J. Neurosurg, 74:441-446 (1991). As mentioned above, the present invention provides a pharmaceutical formulation having an effective amount of a compound of formula I for treating a patient having a bacterial infection. As used herein, an effective amount of the compound is defined as the amount of the compound which, upon administration to a patient, inhibits growth of bacteria, kills bacteria cells, sensitizes bacteria to other antibiotics, or eliminates the bacterial infection entirely in the treated patient. The dosage of the composition will depend on the condition being treated, the particular derivative used, and other clinical factors such as weight and condition of the patient and the route of administration of the compound. However, for oral administration to humans, a dosage of 0.01 to 100 mg/kg/day, preferably 0.01-1 mg/kg/day, is generally sufficient. Effective doses will also vary, as recognized by those skilled in the art, dependent on route of administration, excipient usage, and the possibility of co-usage with other therapeutic treatments including other antibiotic agents. For example, the term “therapeutically effective amount” as used herein for treatment of endotoxemia refers to the amount of compound used is of sufficient quantity to decrease the subject's response to LPS and decrease the symptoms of sepsis. The term “therapeutically effective” therefore includes that the amount of compound sufficient to prevent, and preferably reduce by at least 50%, and more preferably sufficient to reduce by 90%, a clinically significant increase in the plasma level of TNF. The dosage ranges for the administration of compound are those large enough to produce the desired effect. Generally, the dosage will vary with the age, condition, sex, and extent of the infection with bacteria or other agent as described above, in the patient and can be determined by one skilled in the art. The dosage can be adjusted by the individual physician in the event of any contraindications. In any event, the effectiveness of treatment can be determined by monitoring the level of LPS and TNF in a patient. A decrease in serum LPS and TNF levels should correlate with recovery of the patient. In addition, patients at risk for or exhibiting the symptoms of sepsis can be treated by the method as described above, further comprising administering, substantially simultaneously with the therapeutic administration of compound, an inhibitor of TNF, an antibiotic, or both. For example, intervention in the role of TNF in sepsis, either directly or indirectly, such as by use of an anti-TNF antibody and/or a TNF antagonist, can prevent or ameliorate the symptoms of sepsis. Particularly preferred is the use of an anti-TNF antibody as an active ingredient, such as a monoclonal antibody with TNF specificity as described by Tracey, et al. (Nature, 330:662, 1987). A patient who exhibits the symptoms of sepsis may be treated with an antibiotic in addition to the treatment with compound. Typical antibiotics include an aminoglycoside, such as gentamicin or a beta-lactam such as penicillin, or cephalosporin or any of the antibiotics as previously listed above. Therefore, a preferred therapeutic method of the invention includes administering a therapeutically effective amount of cationic compound substantially simultaneously with administration of a bactericidal amount of an antibiotic. Preferably, administration of compound occurs within about 48 hours and preferably within about 2-8 hours, and most preferably, substantially concurrently with administration of the antibiotic. The term “bactericidal amount” as used herein refers to an amount sufficient to achieve a bacteria-killing blood concentration in the patient receiving the treatment. The bactericidal amount of antibiotic generally recognized as safe for administration to a human is well known in the art, and as is known in the art, varies with the specific antibiotic and the type of bacterial infection being treated. Because of the antibiotic, antimicrobial, and antiviral properties of the compounds, they may also be used as preservatives or sterillants of materials susceptible to microbial or viral contamination. The compounds of the invention can be utilized as broad-spectrum antimicrobial agents directed toward various specific applications. Such applications include use of the compounds as preservatives in processed foods when verified as effective against organisms including Salmonella, Yersinia, Shigella, either alone or in combination with antibacterial food additives such as lysozymes; as a topical agent (Pseudomonas, Streptococcus) and to kill odor producing microbes (Micrococci). The relative effectiveness of the compounds of the invention for the applications described can be readily determined by one of skill in the art by determining the sensitivity of any organism to one of the compounds. While primarily targeted at classical Gram-negative-staining bacteria whose outer capsule contains a substantial amount of lipid A, it may also be effective against other organisms with a hydrophobic outer capsule. For example, Mycobacterium spp. have a waxy protective outer coating, and compounds of the invention in combination with antibiotics may provide enhanced effectiveness against Mycobacterial infection, including tuberculosis. In that case, the compounds could be administered nasally (aspiration), by any of several known techniques. Apart from anti-microbial action, the permeability provided by the compounds may enhance introduction of a great variety of substances into microbes. For example, the compounds may be used to enhance introduction of macromolecules such as DNA or RNA into microbes, particularly Gram-negative bacteria. In that case, there may be no need for the traditional vectors (e.g., phages) used to package nucleic acids when transfecting the microbes. Conditions and techniques for introducing such macromolecules into microbes using the compounds of the invention will in most cases be routine. The formulations include those suitable for oral, rectal, nasal, topical (including buccal and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intraocular, intratracheal, and epidural) administration. The formulations may conveniently be presented in unit dosage form and may be prepared by conventional pharmaceutical techniques. Such techniques include the step of bringing into association the active ingredient and the pharmaceutical carrier(s) or excipient(s). In general, the formulations are prepared by uniformly and intimately bringing into associate the active ingredient with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product. Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil emulsion and as a bolus, etc. A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing, in a suitable machine, the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, preservative, surface-active or dispersing agent. Molded tablets may be made by molding, in a suitable machine, a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide a slow or controlled release of the active ingredient therein. Formulations suitable for topical administration in the mouth include lozenges comprising the ingredients in a flavored basis, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the ingredient to be administered in a suitable liquid carrier. Formulations suitable for topical administration to the skin may be presented as ointments, creams, gels and pastes comprising the ingredient to be administered in a pharmaceutical acceptable carrier. A preferred topical delivery system is a transdermal patch containing the ingredient to be administered. Formulations for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter or a salicylate. Formulations suitable for nasal administration, wherein the carrier is a solid, include a coarse powder having a particle size, for example, in the range of 20 to 500 microns which is administered in the manner in which snuff is taken, i.e., by rapid inhalation through the nasal passage from a container of the powder held close up to the nose. Suitable formulations, wherein the carrier is a liquid, for administration, as for example, a nasal spray or as nasal drops, include aqueous or oily solutions of the active ingredient. Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such as carriers as are known in the art to be appropriate. Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, other bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example, sealed ampules and vials, and may be stored in a freeze-dried (lyophilized) conditions requiring only the addition of the sterile liquid carrier, for example, water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tables of the kind previously described. Preferred unit dosage formulations are those containing a daily dose or unit, daily sub-dose, as herein above recited, or an appropriate fraction thereof, of the administered ingredient. It should be understood that in addition to the ingredients, particularly mentioned above, the formulations of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example, those suitable for oral administration may include flavoring agents. The carrier in the pharmaceutical composition must be “acceptable” in the sense of being compatible with the active ingredient of the formulation (and preferably, capable of stabilizing it) and not deleterious to the subject to be treated. Without further elaboration, it is believed that the above description has adequately enabled the present invention. The following specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. All of the publications cited herein, including patents, are hereby incorporated by reference. Examples 1-14 represent typical syntheses of compounds 1 through 343, some of which are shown in Schemes 1 through 16. Example 14 shows stability of compounds 352-354 under acidic, neutral and basic conditions. Example 15 represents other compounds of formula I which can be synthesized using known starting materials and reaction schemes that are similar to those described herein. For example, the hydroxyl groups on cholic acid can be converted into amine groups by the method found in Hsieh et al., Synthesis and DNA Binding Properties of C3-, C12-, and C24-Substituted Amino-Steroids Derived from Bile Acids, Biorganic and Medicinal Chemistry, 1995, vol. 6, 823-838. Example 16 represents MIC and MCB testing, and Example 17 represents the ability of the compounds of formula I to lower the MIC's of other antibiotics. EXAMPLES The examples illustrate particular synthesis of some particular compounds useful in the methods described herein. For example, representative syntheses of some of the compounds 1-343 are presented below. 1H and 13C NMR spectra were recorded on a Varian Gemini 2000 (200 MHz), Varian Unity 300 (300 MHz), or Varian VXR 500 (500 MHz) spectrometer and are referenced to TMS, residual CHCl3 (1H) or CDCl3 (13C), or residual CHD2OD (1H), or CD3OD (13C). IR spectra were recorded on a Perkin Elmer 1600 FTIR instrument. Mass spectrometric data were obtained on a JOEL SX 102A spectrometer. THF was dried over Na/benzophenone and CH2Cl2 was dried over CaH2 prior to use. Other reagents and solvents were obtained commercially and were used as received. Example 1 Syntheses of Compounds 1, 2, 4, 5, 13-20 and 22-27 Compound 13: To a 1 L round-bottom flask were added methyl cholate (30.67 g, 72.7 mmol) in dry THF (600 mL) and LiAlH4 (4.13 g, 109 mmol). After reflux for 48 hours, saturated aqueous Na2SO4(100 mL) was introduced slowly, and the resulted precipitate was filtered out and washed with hot THF and MeOH. Recrystallization from MeOH gave colorless crystals of 13 (28.0 g, 98% yield). m.p. 236.5-238° C.; IR (KBr) 3375, 2934, 1373, 1081 cm−1; 1H NMR (CDCl3/MeOH-d4, 200 MHz) δ 3.98 (bs, 1 H), 3.83 (bs, 1 H), 3.60-3.46 (m, 2 H), 3.38 (bs, 5 H), 2.30-2.10 (m, 2 H), 2.05-1.05 (series of multiplets, 22 H), 1.03 (bs, 3 H), 0.92 (s, 3 H), 0.71 (s, 3 H); 13C NMR (CDCl3/MeOH-d4, 50 MHz) δ 73.89, 72.44, 68.99, 63.51, 48.05, 47.12, 42.49, 40.37, 39.99, 36.62, 36.12, 35.58, 35.40, 32.77, 30.69, 30.04, 29.02, 28.43, 27.27, 23.96, 23.08, 18.00, 13.02; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 417.2992 (55.3%); calcd. 417.2981. Compound 14: To a round-bottom flask were added 13 (28.2 g, 71.7 mmol) in DMF (300 ml), Et3N (20 mL, 143.4 mmol), trityl chloride (25.98 g, 93.2 mmol) and DMAP (0.13 g, 1.07 mmol). The mixture was stirred at 50° C. under N2 for 30 hours followed by the introduction of water (1000 mL) and extraction with EtOAc (5×200 mL). The combined extracts were washed with water and brine and then dried over MgSO4. After removal of solvent in vacuo, the residue was purified using SiO2 chromatography (CH2Cl2, Et2O and MeOH as eluents) to give 14 as a pale yellow solid (31.9 g, 70% yield). m.p. 187° C. (decomposition); IR (KBr) 3405, 2935, 1448, 1075 cm−1; 1H NMR (CDCl3, 200 MHz) δ 7.46-7.42 (m, 6 H), 7.32-7.17 (m, 9 H), 3.97 (bs, 1 H), 3.83 (bs, 1 H), 3.50-3.38 (m, 1 H), 3.01 (bs, 1 H), 2.94 (dd, J=14.2, 12.2 Hz, 2 H), 2.64 (bs, 1 H), 2.51 (bs, 1 H), 2.36-2.10 (m, 2 H), 2.00-1.05 (series of multiplets, 22 H), 0.96 (d, J=5.8 Hz, 3 H), 0.87 (s, 3 H), 0.64 (s, 3 H); 13C NMR (CDCl3, 50 MHz)-144.77, 128.93, 127.91, 127.01, 86.43, 73.35, 72.06, 68.66, 64.28, 47.47, 46.53, 41.74, 41.62, 39.64, 35.57, 35.46, 34.91, 34.82, 32.40, 30.55, 28.21, 27.69, 26.80, 26.45, 23.36, 22.59, 17.83, 12.61; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 659.4069 (100%); calcd. 659.4076. Compound 15: To a round-bottom flask were added 14 (20.0 g, 31.4 mmol) in dry THF (600 mL) and NaH (60% in mineral oil, 6.3 g, 157.2 mmol). The mixture was refluxed for 30 min under N2 followed by addition of allyl bromide (27 mL, 314 mmol). After 60 hours of reflux, additional NaH (3 eq.) and allyl bromide (4 eq.) were added. Following another 50 hours of reflux, water (20 mL) was introduced slowly followed by addition of 1% HCl until the aqueous layer became neutral. The mixture was then extracted with ether (3×100 mL) and the combined extracts were washed with water (100 mL) and brine (2×100 mL). The ether solution was dried over anhydrous Na2SO4, and after removal of solvent, the residue was purified using SiO2 chromatography (hexanes and EtOAc/hexanes 1:8 as eluents) to give 15 (22.76 g, 96% yield) as a pale yellow glass. IR (neat) 2930, 1448, 1087 cm−1; 1H NMR (CDCl3, 200 M Hz) δ 7.48-7.30 (m, 6 H), 7.32-7.14 (m, 9 H), 6.04-5.80 (m, 3 H), 5.36-5.04 (series of multiplets, 6 H), 4.14-3.94 (m, 4 H), 3.74 (td, J=13.8, 5.8 Hz, 2 H), 3.53 (bs, 1 H), 3.20-2.94 (m, 3 H), 3.31 (bs, 1 H), 2.38-1.90 (m, 4 H), 1.90-0.96 (series of multiplets, 20 H), 0.90 (d, J=5.4 Hz, 3 H), 0.89 (s, 3 H), 0.64 (s, 3 H); 13C NMR (CDCl3, 50 MHz) δ 144.83, 136.27, 136.08, 128.94, 127.90, 126.98, 116.46, 115.70, 86.42, 80.94, 79.29, 74.98, 69.52, 69.39, 68.86, 64.39, 46.51, 46.42, 42.67, 42.14, 39.92, 35.63, 35.51, 35.13, 32.45, 28.98, 28.09, 27.66, 27.57, 26.72, 23.32, 23.11, 17.92, 12.69; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 779.5013 (86.1%); calcd. 779.5015. Compound 16: To a three-necked round bottom flask was added 15 (3.34 g, 4.4 mmol) in CH2Cl2 (200 mL) and methanol (100 mL). Through the cold solution (−78° C.) ozone was bubbled through until a blue color persisted. Excess ozone was removed with oxygen flow. The mixture was left in a dry ice-acetone bath for an hour. Methyl sulfide (2.4 mL) was added and 15 minutes later, the mixture was treated with NaBH4 (1.21 g, 32 mmol) in 5% aqueous NaOH solution (10 mL)/methanol (10 mL) and allowed to warm to room temperature. The mixture was washed with brine (3×50 mL), and the combined brine wash was extracted with CH2Cl2 (2×50 mL). The organic solution was dried over MgSO4. After SiO2 chromatography (MeOH (5%) in CH2Cl2), 3.30 g (95% yield) of 16 was isolated as an oil. IR (neat) 3358, 2934, 1448, 1070 cm−1; 1H NMR (CDCl3, 200 MHz) a 7.50-7.42 (m, 6 H), 7.32-7.17 (m, 9 H), 3.80-2.96 (series of multiplets, 20 H), 2.25-0.96 (series of multiplets, 24 H), 0.89 (bs, 6 H), 0.65 (s, 3 H); 13C NMR (CDCl3, 50 MHz) δ 144.73, 128.88, 127.87, 126.96, 86.38, 81.05, 79.75, 76.59, 70.33, 69.66, 69.30, 64.20, 62.25, 62.16, 62.03, 46.77, 46.36, 42.63, 41.77, 39.60, 35.43, 35.23, 35.05, 34.89, 32.42, 28.91, 27.93, 27.56, 27.15, 26.68, 23.35, 22.98, 22.85, 18.15, 12.60; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 791.4860 (100%), calcd. 791.4863. Compound 17: To a round-bottom flask was added 16 (1.17 g, 1.55 mmol) in dry THF (30 mL) under N2 in ice-bath followed by 9-BBN/THF solution (0.5 M, 10.2 mL, 5.51 mmol). The mixture was stirred at room temperature for 12 hours. Aqueous NaOH (20%) (2 mL) and hydrogen peroxide (30%) (2 mL) were added in sequence. The mixture was refluxed for 1 hour followed by the addition of brine (60 mL) and extraction with EtOAc (4×30 mL). The combined extracts were dried over anhydrous Na2SO4. The product (1.01 g, 80% yield) was obtained as a colorless-oil after SiO2 chromatography (5% MeOH in CH2Cl2). IR (neat) 3396, 2936, 1448, 1365, 1089 cm−1; 1H NMR(CDCl3, 200 MHz) δ 7.50-7.42 (m, 6 H), 7.34-7.16 (m, 9 H), 3.90-3.56 (m, 13H), 3.50 (bs, 1 H), 3.40-2.96 (series of multiplets, 6 H), 2.30-0.94 (series of multiplets, 30H), 0.90 (s, 3 H), 0.88 (d, J=5.4 Hz, 3 H), 0.64 (s, 3 H); 13C NMR(CDCl3, 50 MHz) δ 144.73, 128.88, 127.85, 126.94, 86.36, 80.52, 78.90, 76.36, 66.82, 66.18, 65.77, 64.22, 61.53, 61.41, 61.34, 46.89, 46.04, 42.60, 41.59, 39.60, 35.37, 35.27, 34.88, 32.75, 32.44, 32.31, 28.82, 27.65, 27.48, 27.13, 26.77, 23.35, 22.74, 22.38, 18.08, 12.48; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 833.5331 (100%), calcd. 833.5332. Compound 18: To a round-bottom flask were added 16 (3.30 g, 4.29 mmol) in CH2Cl2 (150 mL) and NEt3(2.09 mL, 15.01 mmol). The mixture was put in ice-bath under N2 followed by addition of mesyl chloride (1.10 mL, 14.16 mmol). After 30 minutes, water (30 mL) and brine (200 mL) were added. The CH2Cl2 layer was washed with brine (2×50 mL) and dried over anhydrous Na2SO4. The combined aqueous mixture was extracted with EtOAc (3×100 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. The desired product (3.35 g, 78% yield) was isolated as a pale yellow oil after SiO2 chromatography (EtOAc/hexanes 1:1). IR (neat) 2937, 1448, 1352, 1174, 1120, 924 cm−1; 1H NMR (CDCl3, 200 MHz) δ 7.52-7.40 (m, 6 H), 7.34-7.20, (m, 9 H), 4.42-4.24 (m, 6 H), 3.90-3.64 (m, 4 H), 3.60-3.30 (m, 4 H), 3.24-3.00 (m, 3 H), 3.10 (s, 6 H), 3.05 (s, 3 H), 2.20-1.96 (m, 3 H)1.96-1.60 (m, 8 H), 1.60-0.94 (series of multiplets, 13 H), 0.91 (bs, 6 H), 0.65 (s, 3 H); 13C NMR(CDCl3, 50 MHz) δ 114.68, 128.85, 127.85, 126.96, 86.37, 81.37, 79.58, 76.58, 69.95, 69.43, 69.34, 66.52, 66.31, 65.59, 64.11, 46.80, 46.20, 42.65, 41.48, 39.35, 37.82, 37.48, 35.36, 34.92, 34.73, 32.37, 28.66, 28.01, 27.44, 27.03, 26.72, 23.17, 22.91, 22.72, 18.13, 12.50; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 1205.4176 (81.5%), calcd. 1205.4189. Compound 19: To a round-bottom flask were added 17 (1.01 g, 1.25 mmol) in CH2Cl2 (50 mL) and NEt3 (0.608 mL, 4.36 mmol). The mixture was put in ice-bath under N2 followed by addition of mesyl chloride (0.318 mL, 4.11 mmol). After 30 minutes, water (10 mL) and then brine (80 mL) were added. The CH2Cl2 layer was washed with brine (2×20 mL) and dried over anhydrous Na2SO4. The combined aqueous mixture was extracted with EtOAc (3×40 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. The desired product (1.07 g, 82%) was isolated as a pale yellowish oil after SiO2 chromatography (EtOAc/hexanes 1:1). IR (neat) 2938, 1356, 1176, 1112 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.46-7.43, (m, 6 H), 7.32-7.22 (m, 9 H), 4.40-4.31 (m, 6 H), 3.72-3.64 (m, 2 H), 3.55 (dd, J=6.3, 5.8 Hz, 2H), 3.51 (bs, 1 H), 3.32-3.14 (m, 3 H), 3.14-2.92 (m, 3 H), 3.01 (s, 3 H), 3.01 (s, 3 H), 3.00 (s, 3 H), 2.10-1.92 (m, 10 H), 1.92-1.58 (m, 8 H), 1.56-0.92 (series of multiplets, 12H), 0.90 (s, 3 H), 0.89 (d, J=5.4 Hz, 3 H), 0.64 (s, 3 H); 13C NMR(CDCl3, 75 MHz) δ 144.67, 128.85, 127.85, 126.96, 86.42, 81.06, 79.83, 76.81, 68.12, 68.06, 68.02, 64.26, 64.06, 63.42, 46.76, 46.38, 42.73, 41.87, 39.73, 37.44, 37.32, 37.29, 35.52, 35.48, 35.32, 35.06, 32.53, 30.55, 30.28, 30.02, 29.15, 27.96, 27.69, 27.61, 26.75, 23.52, 23.02, 18.17, 12.64; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 1067.4672 (100%), calcd. 1067.4659. Compound 20: To a round-bottom flask were added 18 (1.50 g, 1.50 mmol) in dry DMSO (20 mL) and NaN3 (0.976 g, 15 mmol). The mixture was heated to 80° C. and stirred under N2 overnight then diluted with water (100 mL). The resulted aqueous mixture was extracted with EtOAc (3×50 mL), and the combined extracts washed with brine and dried over anhydrous Na2SO4. The desired product (0.83 g, 66% yield) was isolated as a clear glass after SiO2 chromatography (EtOAc/hexanes 1:5). IR (neat) 2935, 2106, 1448, 1302, 1114 cm−1; 1H NMR (CDCl3, 200 MHz) δ 7.50-7.42 (m, 6 H), 7.36-7.20 (m, 9 H), 3.84-3.70 (m, 2 H), 3.65 (t, J=4.9 Hz, 2 H), 3.55 (bs, 1 H), 3.44-3.08 (m, 10 H), 3.02 (t, J=6.4 Hz, 2 H), 2.38-0.96 (series of multiplets, 24 H), 0.92 (d, J=5.6 Hz, 3 H), 0.91 (s, 3 H), 0.65 (s, 3 H); 13C NMR (CDCl3, 50 MHz) δ 114.84, 128.97, 127.92, 126.99, 86.42, 81.24, 80.12, 76.59, 67.84, 67.29, 66.66, 64.36, 51.67, 51.44, 51.18, 46.53, 46.23, 42.21, 41.93, 39.73, 35.66, 35.36, 35.06, 34.78, 32.40, 28.95, 27.76, 27.39, 26.87, 23.45, 22.98, 22.92, 17.98, 12.53; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 866.5040 (100%), calcd. 866.5057. Compound 22: To a round-bottom flask were added 20 (830 mg, 0.984 mmol) in MeOH (30 mL) and CH2Cl2 (30 mL) and p-toluenesulfonic acid (9.35 mg, 0.0492 mmol). The solution was stirred at room temperature for 2.5 hours then saturated aqueous NaHCO3 (10 mL) was introduced. Brine (30 mL) was added, and the mixture was extracted with EtOAc (4×20 mL). The combined extracts were dried over anhydrous Na2SO4. The desired product (0.564 g, 95% yield) was isolated as a pale yellowish oil after SiO2 chromatography (EtOAc/hexanes 1:2). IR (neat) 3410, 2934, 2106, 1301, 1112 cm−1; 1H NMR (CDCl3, 200 MHz) δ 3.80-3.54 (m, 7 H), 3.44-3.20 (m, 10 H), 2.35-0.96 (series of multiplets, 24 H), 0.95 (d, J=6.4 Hz, 3 H), 0.92 (s, 3 H), 0.68 (s, 3 H); 13C NMR (CDCl3, 50 MHz) δ 81.10, 80.01, 76.60, 67.75, 67.16, 66.56, 63.63, 51.57, 51.34, 51.06, 46.29, 46.12, 42.12, 41.81, 39.60, 35.55, 35.23, 34.94, 34.66, 31.75, 29.48, 28.81, 27.72, 27.66, 27.29, 23.32, 22.86, 22.80, 17.85, 12.39; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 624.3965 (100%), calcd. 624.3962. Compound 23: To a round-bottom flask were added 19 (1.07 g, 1.025 mmol) and NaN3 (0.666 g, 10.25 mmol) followed the introduction of dry DMSO (15 mL). The mixture was heated up to 80° C. under N2 overnight. After the addition of H2O (100 mL), the mixture was extracted with EtOAc (4×40 mL) and the combined extracts were washed with brine (2×50 mL) and dried over anhydrous Na2SO4. After removal of solvent, the residue was dissolved in MeOH (15 mL) and CH2Cl2 (15 mL) followed by the addition of catalytic amount of p-toluenesulfonic acid (9.75 mg, 0.051 mmol). The solution was stirred at room temperature for 2.5 hours before the addition of saturated NaHCO3 solution (15 mL). After the addition of brine (60 mL), the mixture was extracted with EtOAc (5×30 mL). The combined extracts were washed with brine (50 mL) and dried over anhydrous Na2SO4. The desired product (0.617 g, 94% yield for two steps) was obtained as a yellowish oil after SiO2 chromatography (EtOAc/hexanes 1:2). IR (neat) 3426, 2928, 2094, 1456, 1263, 1107 cm−1; 1H NMR (CDCl3, 300 MHz) δ 3.68-3.56 (m, 3 H), 3.56-3.34 (series of multiplets, 10 H), 3.28-3.00 (series of multiplets, 4 H), 2.20-2.00 (m, 3 H), 1.98-1.55 (series of multiplets, 15 H), 1.55-0.96 (series of multiplets, 13 H), 0.92 (d, J=6.6 Hz, 3 H), 0.89 (s, 3 H), 0.66 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.63, 79.79, 76.04, 64.99, 64.45, 64.30, 63.72, 49.01, 48.94, 48.74, 46.49, 46.39, 42.70, 41.98, 39.80, 35.65, 35.42, 35.28, 35.08, 31.99, 29.78, 29.75, 29.70, 29.49, 29.06, 27.87, 27.79, 27.65, 23.53, 23.04, 22.85, 18.05, 12.59; HRFAB-MS (thioglycerol+Na matrix) m/e: ([M+Na]+) 666.4415 (100%), calcd. 666.4431. Compound 24: To a round-bottom flask were added 22 (0.564 g, 0.938 mmol) in CH2Cl2 (30 mL) and NEt3 (0.20 mL, 1.40 mmol). The mixture was put in ice-bath under N2 followed by addition of mesyl chloride (0.087 mL, 1.13 mmol). After 30 minutes, water (20 mL) and brine (100 mL) were added. The CH2CL2 layer was washed with brine (2×20 mL) and dried over anhydrous Na2SO4. The combined aqueous mixture was extracted with EtOAc (3×30 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. The desired product (0.634 g, 99% yield) was isolated as a pale yellowish oil after SiO2 chromatography (EtOAc/hexanes 1:2). IR (neat) 2935, 2106, 1356, 1175, 1113 cm−1; 1H NMR (CDCl3, 300 MHz) δ 4.20 (t, J=6.8 Hz, 2 H), 3.80-3.75 (m, 1 H), 3.70-3.64 (m, 3 H), 3.55 (bs, 1 H), 3.44-3.01 (m, 10 H), 3.00 (s, 3 H), 2.32-2.17 (m, 3 H), 2.06-2.03 (m, 1 H), 1.90-0.88 (series of multiplets, 20 H), 0.95 (d, J=6.6 Hz, 3 H), 0.91 (s, 3 H), 0.68 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.90, 79.86, 76.43, 70.78, 67.64, 66.99, 66.48, 51.50, 51.26, 50.97, 46.05, 45.96, 42.08, 41.71, 39.51, 37.33, 35.15, 34.86, 34.60, 31.34, 28.73, 27.62, 27.59, 27.51, 25.68, 23.22, 22.80, 22.70, 17.62, 12.33; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 702.3741 (100%), calcd. 702.3737. Compound 25: To a round-bottom flask were added 23 (0.617 g, 0.96 mmol) in CH2Cl2 (30 mL) and NEt3 (0.20 mL, 1.44 mmol). The mixture was put in ice-bath under N2 followed by addition of mesyl chloride (0.089 mL, 1.15 mmol). After 30 minutes, water (20 mL) and brine (120 mL) were added. The CH2Cl2 layer was washed with brine (2×20 mL) and dried over anhydrous Na2SO4. The combined aqueous mixture was extracted with EtOAc (3×30 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. The desired product (0.676 g, 97% yield) was isolated as a pale yellowish oil after removal of solvent. IR (neat) 2934, 2094, 1454, 1360, 1174, 1112 cm−1; 1H NMR (CDCl3, 300 MHz) δ 4.17 (t, J=6.6 Hz, 2 H), 3.65-3.28 (series of multiplets, 11 H), 3.64-3.00 (series of multiplets, 4 H), 2.97 (s, 3 H), 2.18-1.96 (series of multiplets, 16 H), 1.54-0.94 (series of multiplets, 11 H), 0.89 (d, J=6.6 Hz, 3 H), 0.86 (s, 3 H), 0.63 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.47, 79.67, 75.92, 70.84, 64.90, 64.37, 64.17, 48.90, 48.86, 48.66, 46.32, 46.26, 42.63, 41.87, 39.70, 37.39, 35.34, 35.28, 35.20, 34.99, 31.61, 29.68, 29.60, 28.96, 27.78, 27.68, 27.57, 25.79, 23.41, 22.95, 22.74, 17.82, 12.50; HRFAB-MS (thioglycerol matrix) m/e: ([M+H]+) 722.4385 (22.1%), calcd. 722.4387. Compound 26: To a 50 mL round-bottom flask was added 24 (0.634 g, 0.936 mmol) and N-benzylmethylamine (2 mL). The mixture was heated under N2 at 80° C. overnight. Excess N-benzylmethylamine was removed under vacuum, and the residue was subjected to SiO2 chromatography (EtOAc/hexanes 1:2). The desired product (0.6236 g, 95% yield) was isolated as a pale yellow oil. IR (neat) 2935, 2106, 1452, 1302, 1116 cm−1; 1H NMR (CDCl3, 200 MHz) δ 7.32-7.24 (m, 5 H), 3.80-3.76 (m, 1 H), 3.70-3.60 (m, 3 H), 3.54 (bs, 1 H), 3.47 (s, 2 H), 3.42-3.10 (m, 10 H), 2.38-2.05 (m, 5 H), 2.17 (s, 3 H), 2.02-0.88 (series of multiplet, 21 H), 0.93 (d, J=7.0 Hz, 3 H), 0.91 (s, 3 H), 0.66 (s, 3 H); 13C NMR (CDCl3, 50 MHz) δ 139.60, 129.34, 128.38, 127.02, 81.22, 80.10, 76.71, 67.85, 67.29, 66.65, 62.45, 58.38, 51.65, 51.44, 51.16, 46.50, 46.21, 42.40, 42.20, 41.93, 39.72, 35.80, 35.34, 35.05, 34.76, 33.65, 28.93, 27082, 27.75, 27.38, 24.10, 23.45, 22.98, 22.91, 18.05, 12.50; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M−H]+) 703.4748 (90.2%), calcd. 703.4772; ([M+H]+) 705.4911 (100%), calcd. 705.4928; ([M+Na]+) 727.4767 (1.5%), calcd. 727.4748. Compound 27: To a 50 mL round-bottom flask was added 25 (0.676 g, 0.937 mmol) and N-benzylmethylamine (2 mL). The mixture was heated under N2 at 80° C. overnight. Excess N-benzylmethylamine was removed under vacuum and the residue was subjected to SiO2 chromatography (EtOAc/hexanes 1:2). The desired product (0.672 g, 96% yield) was isolated as a pale yellow oil. IR (neat) 2934, 2096, 1452, 1283, 1107 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.34-7.20 (m, 5 H), 3.68-3.37 (series of multiplets, 13 H), 3.28-3.04 (m, 4 H), 2.33 (t, J=7.0 Hz, 2 H), 2.18 (s, 3 H), 2.20-2.00 (m, 3 H), 1.96-1.56 (series of multiplets, 14 H), 1.54-1.12 (m, 10 H), 1.10-0.96 (m, 3 H), 0.91 (d, J=8.7 Hz, 3 H), 0.89 (s, 3 H), 0.65 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 139.48, 129.23, 128.30, 126.96, 80.66, 79.81, 76.08, 65.00, 64.46, 64.34, 62.50, 58.37, 49.02, 48.95, 48.75, 46.65, 46.40, 42.69, 42.43, 42.00, 39.83, 35.86, 35.45, 35.30, 35.10, 33.83, 29.81, 29.78, 29.72, 29.09, 27.88, 27.81, 27.66, 24.19, 23.57, 23.06, 22.87, 18.15, 12.62; HRFAB-MS (thioglycerol matrix) m/e: ([M+H]+) 747.5406 (77.2%), calcd. 747.5398. Compound 1: To a round-bottom flask were added 26 (0.684 g, 0.971 mmol) in dry THF (30 mL) and LiAlH4 (113.7 mg, 3.0 mmol) under N2. The mixture was stirred at room temperature for 12 hours, and then Na2SO4.10H2O powder (10 g) was added slowly. After the grey color disappeared, the mixture was filtered through Celite and washed with dry THF. The product (0.581 g, 95% yield) was obtained as a colorless glass. IR (neat) 3372, 2937, 1558, 1455, 1362, 1102 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.34-7.20 (m, 5 H), 3.68-3.48 (m, 5 H), 3.47 (s, 2 H), 3.29 (bs, 1 H), 3.22-3.00 (m, 3 H), 2.96-2.80 (m, 6 H), 2.32 (t, J=6.8, 5.4 Hz, 2 H), 2.17 (s, 3 H), 2.20-2.00 (m, 3 H), 1.96-0.96 (series of multiplets, 27 H), 0.93 (d, J=6.8 Hz, 3 H), 0.90, (s, 3 H), 0.67 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 139.50, 129.22, 128.31, 126.96, 80.76, 79.85, 76.10, 70.90, 70.33, 70.24, 62.48, 58.27, 46.55, 46.45, 42.72, 42.58, 42.33, 41.99, 39.77, 35.78, 35.37, 35.01, 33.73, 29.07, 27.95, 27.71, 24.06, 23.46, 22.99, 18.14, 12.55; HRFAB-MS (thioglycerol matrix) m/e: ([M+H]+) 627.5211 (100%), calcd. 627.5213. HCl salt of compound 1: Compound 1 was dissolved in a minimum amount of CH2Cl2 and excess HCl in ether was added. Solvent and excess HCl were removed in vacuo and a noncrystalline white powder was obtained. 1H NMR (methanol-d4/15% CDCl3, 300 MHz) δ 7.61-7.57 (m, 2 H), 7.50-7.48 (m, 3 H), 4.84 (bs, 10 H), 4.45 (bs, 1H), 4.30 (bs, 1 H), 3.96-3.82 (m, 2 H), 3.78-3.69 (m, 2 H), 3.66 (bs, 1 H), 3.59-3.32 (series of multiplets, 4 H), 3.28-3.02 (m, 8 H), 2.81 (s, 3 H), 2.36-2.15 (m, 4 H), 2.02-1.68 (m, 8 H), 1.64-0.90 (series of multiplets, 12 H), 1.01 (d, J=6.35 Hz, 3 H), 0.96 (s, 3 H), 0.73 (s, 3 H); 13C NMR (methanol-d4/15% CDCl3, 75 MHz) δ 132.31, 131.20, 130.92, 130.40, 83.13, 81.09, 78.48, 65.54, 64.98, 64.11, 60.87, 57.66, 47.51, 46.91, 43.52, 43.00, 41.38, 41.19, 41.16, 40.75, 40.30, 36.37, 36.08, 36.00, 35.96, 33.77, 29.68, 29.34, 28.65, 28.37, 24.42, 24.25, 23.33, 21.51, 18.80, 13.04. Compound 2: To a round-bottom flask were added 27 (0.82 g, 1.10 mmol) in dry THF (150 mL) and LiAlH4 (125 mg, 3.30 mmol) under N2. The mixture was stirred at room temperature for 12 hours and Na2SO4.10H2O powder (10 g) was added slowly. After the grey color disappeared, the mixture was filtered through a cotton plug and washed with dry THF. THF was removed in vacuo and the residue dissolved in CH2Cl2 (50 mL). After filtration, the desired product was obtained as a colorless glass (0.73 g, 99% yield). IR (neat) 3362, 2936, 2862, 2786, 1576, 1466, 1363, 1103 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.32-7.23 (m, 5 H), 3.67-3.63 (m, 1 H), 3.60-3.57 (m, 1 H), 3.53 (t, J=6.4 Hz, 2 H), 3.47 (s, 2 H), 3.46 (bs, 1 H), 3.24-3.17(m, 2 H), 3.12-2.99 (m, 2 H), 2.83-2.74 (series of multiplets, 6 H), 2.30 (t, J=7.3 Hz, 2 H), 2.15 (s, 3 H), 2.20-2.00 (m, 3 H), 1.95-1.51 (series of multiplets, 20 H), 1.51-1.08, (series of multiplets, 10 H), 1.06-0.80 (m, 3 H), 0.87 (d, J=8.1 Hz, 3 H), 0.86 (s, 3 H), 0.61 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 139.35, 129.16, 128.22, 126.88, 80.44, 79.29, 75.96, 66.70, 66.52, 66.12, 62.45, 58.26, 46.76, 46.27, 42.69, 42.41, 42.02, 40.68, 40.10, 40.02, 39.82, 35.84, 35.47, 35.30, 35.06, 34.15, 34.09, 34.03, 33.80, 28.96, 27.93, 27.75, 27.71, 24.32, 23.53, 23.03, 22.75, 18.17, 12.58; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 691.5504 (38.5%), calcd. 691.5502. HCl salt of compound 2: Compound 2 was dissolved in a minimum amount of CH2Cl2 and excess HCl in ether was added. Removal of the solvent and excess HCl gave a noncrystalline white powder. 1H NMR (methanol-d4/15% CDCl3, 300 MHz) δ 7.60-7.59(m, 2 H), 7.50-7.47 (m, 3 H), 4.82 (bs, 10 H), 4.43 (bs, 1 H), 4.32 (bs, 1 H), 3.85-3.79 (m, 1 H), 3.75-3.68 (m, 1 H), 3.64 (t, J=5.74 Hz, 2 H), 3.57 (bs, 1 H), 3.36-3.28 (m, 2 H), 3.25-3.00 (series of multiplets, 10 H), 2.82 (s, 3 H), 2.14-1.68 (series of multiplets, 19 H), 1.65-1.15 (series of multiplets, 11 H), 0.98 (d, J=6.6 Hz, 3 H), 0.95 (s, 3 H), 0.72 (s, 3 H); 13C NMR (methanol-d4/15% CDCl3, 75 MHz) δ 132.21, 131.10, 130.58, 130.28, 81.96, 80.72, 77.60, 66.84, 66.58, 66.12, 61.03, 57.60, 44.16, 42.77, 40.62, 39.57, 39.43, 36.28, 36.03, 35.96, 35.78, 33.65, 29.48, 29.27, 29.11, 29.01, 28.61, 28.56, 28.35, 24.25, 23.56, 23.30, 21.17, 18.64, 12.90. Compound 4: A suspension of 1 (79.1 mg, 0.126 mmol) and aminoiminomethanesulfonic acid (50.15 mg, 0.404 mmol) in methanol and chloroform was stirred at room temperature for 24 hours, and the suspension became clear. An ether solution of HCl (1 M, 1 mL) was added followed by the removal of solvent with N2 flow. The residue was dissolved in H2O (5 mL) followed by the addition of 20% aqueous NaOH (0.5 mL). The resulting cloudy mixture was extracted with CH2Cl2 (4×5 mL). The combined extracts were dried over anhydrous Na2SO4. Removal of solvent gave the desired product (90 mg, 95%) as white powder. m.p. 111-112° C. IR (neat) 3316, 2937, 1667, 1650, 1556, 1454, 1348, 1102 cm−1; 1H NMR (5% methanol-d4/CDCl3, 300 MHz) δ 7.26-7.22 (m, 5 H), 4.37 (bs, 3 H), 3.71-3.51(series of multiplets, 5 H), 3.44 (s, 2 H), 3.39-3.10 (series of multiplets, 10 H), 2.27 (t, J=6.83 Hz, 2 H), 2.13 (s, 3 H), 2.02-0.94 (series of multiplets, 33 H), 0.85 (d, J=5.62 Hz, 3 H), 0.84 (s, 3 H), 0.61 (s, 3 H); 13C NMR (5% methanol-d4/CDCl3, 75 MHz) δ 158.54, 158.48, 158.43, 138.27, 129.47, 128.32, 127.19, 81.89, 80.30, 77.34, 69.02, 68.46, 67.21, 62.36, 58.00, 47.36, 46.18, is 43.26, 43.00, 42.73, 42.18, 41.48, 39.32, 35.55, 34.97, 34.89, 34.67, 33.63, 28.93, 28.28, 27.53, 27.16, 23.96, 23.28, 23.16, 22.77, 18.36, 12.58; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 753.5858 (100%), calcd. 753.5867. HCl salt of compound 4: Compound 4 was dissolved in minimum amount of CH2Cl2 and MeOH followed by addition of excess HCl in ether. The solvent was removed by N2 flow, and the residue was subjected to high vacuum overnight. The desired product was obtained as noncrystalline white powder. 1H NMR (methanol-d4/20% CDCl3, 300 MHz) δ 7.58 (bs, 2 H), 7.50-7.48 (m, 3 H), 4.76 (bs, 13 H), 4.45 (d, J=12.9 Hz, 1 H), 4.27 (dd, 1 H, J=12.9, 5.4 Hz), 3.82-3.00 (series of multiplets, 17 H), 2.81-2.80 (m, 3 H), 2.20-1.02 (series of multiplets, 27 H), 0.98 (d, J=6.59 Hz, 3 H), 0.95 (s, 3 H), 0.72 (s, 3 H); 13C NMR (methanol-d4/20% CDCl3, 75 MHz) δ 158.88, 158.72, 132.00, 131.96, 130.98, 130.15, 82.51, 81.07, 78.05, 68.50, 68.02, 67.94, 67.10, 60.87, 60.53, 57.38, 47.16, 46.91, 43.91, 43.11, 43.01, 42.91, 42.55, 40.28, 39.88, 39.95, 35.90, 35.73, 35.64, 33.53, 29.18, 28.35, 27.99, 24.02, 23.30, 21.35, 18.52, 18.44, 13.06. Compound 5: A suspension of 2 (113 mg, 0.169 mmol) and aminoiminomethanesulfonic acid (67.1 mg, 0.541 mmol) in methanol and chloroform was stirred at room temperature for 24 hours. HCl in ether (1 M, 1 mL) was added followed by the removal of solvent with N2 flow. The residue was subject to high vacuum overnight and dissolved in H2O (5 mL) followed by the addition of 20% NaOH solution (1.0 mL). The resulting mixture was extracted with CH2Cl2 (5×5 mL). The combined extracts were dried over anhydrous Na2SO4. Removal of solvent gave desired the product (90 mg, 95% yield) as a white solid. m.p. 102-104° C. IR (neat) 3332, 3155, 2939, 2863, 1667, 1651, 1558, 1456, 1350, 1100 cm−1; 1H NMR (5% methanol-d4/CDCl3, 300 MHz) δ 7.35-7.24 (m, 5 H), 3.75-3.64 (m, 1 H), 3.57 (bs, 5 H), 3.50 (s, 2H), 3.53-3.46 (m, 1 H), 3.40-3.10 (series of multiplets, 14 H), 2.34 (t, J=7.31 Hz, 2 H), 2.19 (s, 3 H), 2.13-0.96 (series of multiplets, 36H), 0.91 (bs, 6 H), 0.66 (s, 3 H); 13C NMR (5% methanol-d4/CDCl3, 75 MHz) δ 157.49, 157.31, 157.23, 138.20, 129.52, 128.34, 127.23, 81.17, 79.19, 76.42, 65.63, 65.03, 64.70, 62.36, 58.02, 47.23, 46.24, 42.89, 42.18, 41.45, 39.45, 39.40, 39.30, 38.71, 35.61, 35.55, 35.02, 34.82, 33.69, 29.87, 29.59, 29.42, 28.84, 27.96, 27.56, 23.95, 23.40, 22.82, 22.64, 18.28, 12.54; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 795.6356 (84.3%), calcd. 795.6337. HCl salt of compound 5: Compound 5 was dissolved in minimum amount of CH2Cl2 and MeOH followed by the addition of excess HCl in ether. The solvent and excess HCl were removed by N2 flow and the residue was subject to high vacuum overnight. The desired product was obtained as noncrystalline white powder. 1H NMR (methanol-d4/10% CDCl3, 300 MHz) δ 7.62-7.54 (m, 2 H), 7.48-7.44 (m, 3 H), 4.84 (bs, 16 H), 4.46 (d, J=12.7 Hz, 1 H), 4.26 (dd, J=12.7, 3.42 Hz, 1 H), 3.78-3.56 (series of multiplets, 5 H), 3.38-3.05 (series of multiplets, 13 H), 2.80 (d, 3 H), 2.19-2.04 (m, 3 H), 2.02-1.04 (series of multiplets, 30 H), 0.98 (d, J=6.35 Hz, 3 H), 0.95 (s, 3 H), 0.72 (s, 3H); 13C NMR (methanol-d4/10% CDCl3, 75 MHz) δ 158.75, 158.67, 132.32, 131.24, 130.83, 130.43, 82.49, 81.02, 77.60, 66.47, 65.93, 61.19, 60.85, 57.69, 47.79, 47.60, 44.29, 43.07, 40.86, 40.42, 40.19, 40.09, 39.76, 36.68, 36.50, 36.15, 35.94, 33.91, 30.75, 30.46, 29.74, 29.33, 28.71, 24.41, 24.03, 23.38, 22.21, 22.16, 18.59, 18.52, 13.09. Example 2 Syntheses of Compounds 3, 28 and 29 Compound 28: A suspension of 19 (0.641 g, 0.614 mmol) and KCN (0.40 g, 6.14 mmol) in anhydrous DMSO (5 mL) was stirred under N2 at 80° C. overnight followed by the addition of H2O (50 mL). The aqueous mixture was extracted with EtOAc (4×20 mL). The combined extracts were washed with brine once, dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was dissolved in CH2Cl2 (3 mL) and MeOH (3 mL) and catalytic amount of p-toluenesulfonic acid (5.84 mg, 0.03 mmol) was added. The solution was stirred at room temperature for 3 hours before the introduction of saturated NaHCO3 solution (10 mL). After the addition of brine (60 mL), the mixture was extracted with EtOAc (4×30 mL). The combined extracts were washed with brine once and dried over anhydrous Na2SO4 and concentrated. The residue afforded the desired product (0.342 g, 92% yield) as pale yellowish oil after column chromatography (silica gel, EtOAc/hexanes 2:1). IR (neat) 3479, 2936, 2864, 2249, 1456, 1445, 1366, 1348, 1108 cm−1; 1H NMR (CDCl3, 300 MHz) δ 3.76-3.53 (m, 7 H), 3.32-3.06 (series of multiplets, 4 H), 2.57-2.46 (m, 6 H), 2.13-1.00 (series of multiplets, 31 H), 0.93 (d, J=6.35 Hz, 3 H), 0.90 (s, 3 H), 0.67 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 119.91, 119.89, 80.75, 79.65, 76.29, 65.83, 65.37, 65.19, 63.63, 46.57, 46.44, 42.77, 41.79, 39.71, 35.63, 35.26, 35.02, 32.00, 29.46, 29.03, 27.96, 27.74, 26.64, 26.42, 26.12, 23.56, 22.98, 22.95, 18.24, 14.65, 14.54, 14.30, 12.60; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 618.4247 (67.8%), calcd. 618.4247. Compound 29: To a solution of 28 (0.34 g, 0.57 mmol) in dry CH2Cl2 (15 mL) under N2 at 0° C. was added NEt3 (119.5 μL, 0.857 mmol) followed by the addition of mesyl chloride (53.1 μL, 0.686 mmol). The mixture was allowed to stir at 0° C. for 30 minutes before the addition of H2O (6 mL). After the introduction of brine (60 mL), the aqueous mixture was extracted with EtOAc (4×20 mL). The combined extracts were washed with brine once, dried over anhydrous Na2SO4 and concentrated. To the residue was added N-benzylmethyl amine (0.5 mL) and the mixture was stirred under N2 at 80° C. overnight. Excess N-benzylmethylamine was removed in vacuo and the residue was subject to column chromatography (silica gel, EtOAc/hexanes 2:1 followed by EtOAc) to afford product (0.35 g, 88% yield) as a pale yellow oil. IR (neat) 2940, 2863, 2785, 2249, 1469, 1453, 1366, 1348, 1108 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.34-7.21 (m, 5H), 3.76-3.69 (m, 1 H), 3.64-3.50 (m, 4 H), 3.48 (s, 2 H), 3.31-3.05 (series of multiplets, 4 H), 2.52-2.46 (m, 6 H), 2.33 (t, J=7.32 H, 2 Hz), 2.18 (s, 3 H), 2.13-0.95 (series of multiplets, 30 H), 0.91 (d, J=6.80 H, 3 Hz), 0.90 (s, 3 H), 0.66 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 139.37, 129.17, 128.26; 126.93, 119.96, 119.91, 80.73, 79.59, 76.26, 65.79, 65.35, 65.13, 62.47, 58.25, 46.74, 46.40, 42.72, 42.38, 41.76, 39.68, 35.78, 35.22, 34.98, 33.79, 28.99, 27.92, 27.71, 26.63, 26.38, 26.09, 24.21, 23.54, 22.96, 22.90, 18.28, 14.62, 14.51, 14.26, 12.58; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 699.5226 (100%), calcd. 699.5213. Compound 3: A solution of 29 (0.074 g, 0.106 mmol) in anhydrous THF (10 mL) was added dropwise to a mixture of AlCl3 (0.1414 g, 1.06 mmol) and LiAlH4 (0.041 g, 1.06 mmol) in dry THF (10 mL). The suspension was stirred for 24 hours followed by the addition of 20% NaOH aqueous solution (2 mL) at ice-bath temperature. Anhydrous Na2SO4 was added to the aqueous slurry. The solution was filtered and the precipitate washed twice with THF. After removal of solvent, the residue was subject to column chromatography (silica gel, MeOH/CH2Cl2 1:1 followed by MeOH/CH2Cl2/NH3.H2O 4:4:1) to afford the desired product (0.038 g, 50% yield) as a clear oil. IR (neat) 3362, 2935, 2863, 2782, 1651, 1574, 1568, 1557, 1471, 1455, 1103 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.32-7.22 (m, 5 H), 3.60-3.02 (series of broad multiplets, 18 H), 2.90-2.70 (m, 5H), 2.33 (t, J=7.20 Hz, 2 H), 2.24-2.04 (m, 3 H), 2.18 (s, 3 H), 1.96-0.96 (series of multiplets, 30 H), 0.90 (d, J=7.57 Hz, 3 H), 0.89 (s, 3 H), 0.64 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 139.44, 129.24, 128.31, 126.97, 80.63, 79.65, 75.97, 68.44, 68.00, 67.96, 62.54, 58.40, 46.77, 46.30, 42.73, 42.43, 42.07, 41.92, 41.74, 41.72, 39.81, 35.82, 35.48, 35.07, 33.84, 31.04, 30.30, 30.10, 29.03, 28.11, 27.82, 27.81, 27.74, 27.67, 27.64, 24.31, 23.50, 23.04, 22.93, 18.22, 12.63; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 711.6139 (100%), calcd. 711.6152; ([M+Na]+) 733.5974 (46.1%), calcd. 733.5972. Example 3 Syntheses of Compounds 6, 7, and 30-33 Compound 30: Cholic acid (3.0 g, 7.3 mmol) was dissolved in CH2Cl2 (50 mL) and methanol (5 mL). Dicyclohexylcarbodiimide (DCC) (1.8 g, 8.8 mmol) was added followed by N-hydroxysuccinimide (˜100 mg) and benzylmethylamine (1.1 g, 8.8 mmol). The mixture was stirred for 2 hours, then filtered. The filtrate was concentrated and chromatographed (SiO2, 3% MeOH in CH2Cl2) to give 3.0 g of a white solid (81% yield). m.p. 184-186° C.; IR (neat) 3325, 2984, 1678 cm−1; 1H NMR (CDCl3, 200 MHz) δ 7.21 (m, 5 H), 4.51 (m, 2 H), 3.87 (m, 1 H), 3.74 (m, 2 H), 3.36 (m, 2 H), 2.84 (s, 3 H), 2.48-0.92 (series of multiplets, 28 H), 0.80 (s, 3 H), 0.58 (d, J=6.5 Hz, 3 H); 13C NMR (CDCl3, 50 MHz) δ 174.30, 173.94, 137.36, 136.63, 128.81, 128.46, 127.85, 127.50, 127.18, 126.28, 72.96, 71.76; 68.35, 53.39, 50.65, 48.77, 46.91, 46.33, 41.44, 39.36, 39.18, 35.76, 35.27, 34.76, 33.87, 31.54, 34.19, 31.07, 30.45, 28.11, 27.63, 26.14, 25.59, 24.92, 23.26, 17.51, 12.41; FAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 512 (100%), calcd. 512. Compound 31: Compound 30 (2.4 g, 4.7 mmol) was added to a suspension of LiAlH4 (0.18 g, 4.7 mmol) in THF (50 mL). The mixture was refluxed for 24 hours, then cooled to 0° C. An aqueous solution of Na2SO4 was carefully added until the grey color of the mixture dissipated. The salts were filtered out, and the filtrate was concentrated in vacuo to yield 2.1 g of a white solid (88%). The product proved to be of sufficient purity for further reactions. m.p. 70-73° C.; IR (neat) 3380, 2983, 1502 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.23 (m, 5 H), 3.98 (bs, 2 H), 3.81 (m, 3 H), 3.43 (m, 3 H), 2.74 (m, 2 H), 2.33 (m, 3 H), 2.25 (s, 3 H), 2.10-0.90 (series of multiplets, 24 H), 0.98 (s, 3 H), 0.78 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 135.72, 129, 63, 128.21, 128.13, 125.28, 72.91, 71.63, 62.05, 60.80, 56.79, 47.00, 46.23, 41.44, 40.81, 39.41, 35.42, 35.24, 34.63, 34.02, 33.22, 31.73, 30.17, 29.33, 29.16, 28.02, 27.49, 26.17, 25.55, 23.10, 22.48, 22.33, 17.54, 12.65; FAB-MS (thioglycerol matrix) m/e: ([M+H]+) 498 (100%), calcd. 498. Compound 32: Compound 31 (0.36 g, 0.72 mmol) was dissolved in CH2Cl2 (15 mL) and Bocglycine (0.51 g, 2.89 mmol), DCC (0.67 g, 3.24 mmol) and dimethylaminopyridine (DMAP) (˜100 mg) were added. The mixture was stirred under N2 for 4 hours then filtered. After concentration and chromatography (SiO2, 5% MeOH in CH2Cl2), the product was obtained as a 0.47 g of a clear glass (68%). 1H NMR (CDCl3, 300 MHz) δ 7.30 (m, 5 H), 5.19 (bs, 1 H), 5.09 (bs, 3 H), 5.01 (bs, 1 H), 4.75 (m, 1 H), 4.06-3.89 (m, 6 H), 2.33 (m, 2 H), 2.19 (s, 3 H) 2.05-1.01 (series of multiplets, 26H), 1.47 (s, 9 H), 1.45 (s, 18 H), 0.92 (s, 3 H), 0.80 (d, J=6.4 Hz, 3 H), 0.72 (s, 3 H). 13C NMR (CDCl3, 75 MHz) δ 170.01, 169.86, 169.69, 155.72, 155.55, 139.90, 129.05, 128.17, 126.88, 79.86, 76.53, 75.09, 72.09, 62, 35, 57.88, 47.78, 45.23, 43.12, 42.79, 42.16, 40.81, 37.94, 35.51, 34.69, 34.57, 34.36, 33.30, 31.31, 29.66, 28.80, 28.34, 27.22, 26.76, 25.61, 24.02, 22.83, 22.47, 17.93, 12.19; FAB-MS (thioglycerol matrix) m/e: ([M+H]+) 970 (100%), calcd. 970. Compound 33: Compound 31 (0.39 g, 0.79 mmol) was dissolved in CH2Cl2 (15 mL) and Boc-β-alanine (0.60 g, 3.17 mmol), DCC (0.73 g, 3.56 mmol) and dimethylaminopyridine (DMAP) (˜100 mg) were added. The mixture was stirred under N2 for 6 hours then filtered. After concentration and chromatography (SiO2, 5% MeOH in CH2Cl2), the product was obtained as a 0.58 g of a clear glass (72%). IR (neat) 3400, 2980, 1705, 1510 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.27 (m, 5 H), 5.12 (bs, 4 H), 4.93 (bs, 1 H), 4.71 (m, 1 H), 3.40 (m, 12 H), 2.59-2.48 (m, 6 H), 2.28 (m, 2 H), 2.17 (s, 3 H) 2.05-1.01 (series of multiplets, 26H), 1.40 (s, 27 H), 0.90 (s, 3 H), 0.77 (d, J=6.1 Hz, 3H), 0.70 (s, 3 H). 13C NMR (CDCl3, 75 MHz) δ 171.85, 171.50, 171.44, 155.73, 138.62, 129.02, 128.09, 126.87, 79.18, 75.53, 74.00, 70.91, 62.20, 57.67, 47.84, 44.99, 43.28, 41.98, 40.73, 37.67, 36.12, 34.94, 34.65, 34.47, 34.20, 33.29, 31.23, 29.57, 28.74, 28.31, 28.02, 27.86, 27.12, 26.73, 25.46, 24.86, 23.95, 22.77, 22.39, 17.91, 12.14; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 1011.6619 (100%), calcd. 1011.6634. Compound 6: Compound 32 (0.15 g, 0.15 mmol) was stirred with excess 4 N HCl in dioxane for 40 minutes. The dioxane and HCl were removed in vacuo leaving 0.12 g of a clear glass (˜100%). 1H NMR (CD3OD, 300 MHz) δ 7.62 (bs, 2 H), 7.48 (bs, 3 H), 5.30 (bs, 1 H), 5.11 (bs, 1 H), 4.72 (bs (1 H), 4.46 (m, 1 H), 4.32 (m, 1 H) 4.05-3.91 (m, 4H), 3.10 (m, 2 H), 2.81 (s, 3 H), 2.15-1.13 (series of multiplets, 25 H), 1.00 (s, 3 H), 0.91 (bs, 3 H), 0.82 (s, 3 H). 13C NMR (CD3OD, 125 MHz) δ 166.86, 166.50, 131.09, 130.18, 129.17, 128.55, 76.60, 75.43, 72.61, 72.04, 70.40, 66.22, 60.07, 58.00, 57.90, 54.89, 54.76, 46.44, 44.64, 43.39, 42.22, 38.56, 36.78, 34.14, 33.92, 33.84, 31.82, 30.54, 29.67, 28.79, 27.96, 26.79, 26.00, 24.99, 23.14, 22.05, 21.82, 19.91, 17.27, 11.60; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M−4 Cl−3 H]+) 669.4576 (100%), calcd. 669.4591. Compound 7: Compound 33 (0.20 g, 0.20 mmol) was stirred with excess 4 N HCl in dioxane for 40 minutes. The dioxane and HCl were removed in vacuo leaving 0.12 g of a clear glass (˜100%). 1H NMR (CD3OD, 500 MHz) δ 7.58 (bs, 2 H), 7.49 (bs, 3 H), 5.21 (bs, 1 H), 5.02 (bs, 1 H), 4.64 (m, 1 H), 4.44 (m, 1 H), 4.28 (m, 1 H), 3.30-2.84 (m, 14 H), 2.80 (s, 3 H), 2.11-1.09 (series of multiplets, 25 H), 0.99 (s, 3 H), 0.89 (d, J=4.1 Hz, 3 H), 0.80 (s, 3 H); 13C NMR (CD3OD, 125 MHz) δ 171.92, 171.56, 171.49, 132.44, 131.32, 131.02, 130.51, 78.13, 76.61, 61.45, 57.94, 46.67, 44.80, 42.36, 40.85, 39.33, 37.03, 36.89, 36.12, 36.09, 35.79, 35.63, 33.81, 33.10, 32.92, 32.43, 30.28, 28.43, 28.04, 26.65, 24.02, 22.86, 21.98, 18.70, 12.68; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M−4 Cl−3 H]+) 711.5069 (43%), calcd. 711.5061. Example 4 Syntheses of Compounds 8-10 and 34-40 Compound 34: Diisopropyl azodicarboxylate (DIAD) (1.20 mL, 6.08 mmol) was added to triphenylphosphine (1.60 g, 6.08 mmol) in THF (100 mL) at 0° C. and was stirred for half an hour during which time the yellow solution became a paste. Compound 14 (2.58 g, 4.06 mmol) and p-nitrobenzoic acid (0.81 g, 4.87 mmol) were dissolved in THF (50 mL) and added to the paste. The resulted mixture was stirred at ambient temperature overnight. Water (100 mL) was added and the mixture was made slightly basic by adding NaHCO3 solution followed by extraction with EtOAc (3×50 mL). The combined extracts were washed with brine once and dried over anhydrous Na2SO4. The desired product (2.72 g, 85% yield) was obtained as white powder after SiO2 chromatography (Et2O/hexanes 1:2). m.p. 207-209° C.; IR (KBr) 3434, 3056, 2940, 2868, 1722, 1608, 1529, 1489, 1448, 1345 cm−1; 1H NMR (CDCl3, 300 MHz) δ 8.30-8.26 (m, 2 H), 8.21-8.16 (m, 2 H), 7.46-7.42 (m, 6 H), 7.31-7.18 (m, 9 H)5.33 (bs, 1 H), 4.02 (bs, 1 H), 3.90 (bs, 1 H), 3.09-2.97 (m, 2 H), 2.68 (td, J=14.95, 2.56 Hz, 1 H), 2.29-2.19 (m, 1 H), 2.07-1.06 (series of multiplets, 24 H), 1.01 (s, 3 H), 0.98 (d, J=6.6 Hz, 3 H), 0.70 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 164.21, 150.56, 144.70, 136.79, 130.77, 128.88, 127.86, 126.98, 123.70, 86.47, 73.24, 73.00, 68.70, 64.22, 47.79, 46.79, 42.15, 39.76, 37.47, 35.52, 35.34, 34.23, 33.79, 32.46, 31.12, 28.74, 27.71, 26.85, 26.30, 25.16, 23.41, 17.98, 12.77; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 808.4203 (53.8%), calcd. 808.4189. The nitrobenzoate (2.75 g, 3.5 mmol) was dissolved in CH2Cl2 (40 mL) and MeOH (20 mL) and 20% aqueous NaOH (5 mL) were added. The mixture was heated up to 60° C. for 24 hours. Water (100 mL) was introduced and extracted with EtOAc. The combined extracts were washed with brine and dried over anhydrous Na2SO4. The desired product (1.89 g, 85% yield) was obtained as white solid after SiO2 chromatography (3% MeOH in CH2Cl2 as eluent). m.p. 105-106° C.; IR (KBr) 3429, 3057, 2936, 1596, 1489, 1447, 1376, 1265, 1034, 704 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.46-7.42 (m, 6 H), 7.32-7.19 (m, 9 H), 4.06 (bs, 1 H), 3.99-(bs, 1 H), 3.86 (bd, J=2.44 Hz, 1 H), 3.09-2.97 (m, 2 H), 2.47 (td, J-=14.03, 2.44 Hz, 1 H), 2.20-2.11 (m, 1H), 2.04-1.04 (series of multiplets, 25 H), 0.97 (d, J=6.59 Hz, 3 H), 0.94 (s, 3 H), 0.68 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 144.70, 128.88, 127.86, 126.97, 86.45, 73.31, 68.84, 67.10, 64.23, 47.71, 46.74, 42.10, 39.70, 36.73, 36.73, 36.15, 35.53, 35.45, 34.45, 32.46, 29.93, 28.67, 27.86, 27.71, 26.87, 26.04, 23.43, 23.16, 17.94, 12.75; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 659.4064 (100%), calcd. 659.4076. Compound 35: To a round-bottom flask were added 34 (2.0 g, 3.14 mmol), NaH (60% in mineral oil, 3.8 g, 31.4 mmol) and THF (150 mL). The suspension was refluxed for 2 hours followed by the addition of allyl bromide (2.72 mL, 31.4 mL). After refluxing for 28 hours, another 10 eq. of NaH and allyl bromide were added. After 72 hours, another 10 eq. of NaH and allyl bromide were added. After 115 hours, TLC showed almost no starting material or intermediates. Water (100 mL) was added to the suspension carefully, followed by extraction with EtOAc (5×50 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. The desired product (1.81 g, 79% yield) was obtained as a yellowish glass after SiO2 chromatography (5% EtOAc/hexanes). IR (neat) 3060, 3020, 2938, 2865, 1645, 1596, 1490, 1448, 1376, 1076, 705 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.46-7.42 (m, 6 H), 7.31-7.18 (m, 9 H), 6.06-5.85 (m, 3 H), 5.35-5.20 (m, 3 H), 5.15-5.06 (m, 3 H), 4.10-4.00 (m, 2 H), 3.93-3.90 (m, 2 H), 3.85-3.79 (ddt, J=13.01, 4.88, 1.59 Hz, 1 H), 3.73-3.66 (ddt, i=13.01, 5.38, 1.46 Hz, 1 H), 3.58 (bs, 1 H), 3.54 (bs, 1 H), 3.32 (d, J=2.93 Hz, 1 H), 3.07-2.96 (m, 2 H), 2.36 (td, J=13.67, 2.68 Hz, 1 H), 2.24-2.10 (m, 2 H), 2.03-1.94 (m, 1 H), 1.87-0.86 (series of multiplets, 20 H), 0.91 (s, 3 H), 0.90 (d, J=6.83 Hz, 3 H), 0.64 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 144.77, 136.29, 136.21, 136.13, 128.90, 127.86, 126.94, 116.13, 115.51, 115.42, 86.44, 81.11, 75.65, 73.92, 69.40, 68.81, 64.43, 46.68, 46.54, 42.93, 39.93, 36.98, 35.66, 35.14, 35.14, 32.83, 32.54, 30.48, 28.51, 27.72, 27.64, 26.82, 24.79, 23.65, 23.43, 23.40, 18.07, 12.80; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 757.5185 (12.9%), calcd. 757.5196. Compound 36: Ozone was bubbled through a solution of 35 (0.551 g, 0.729 mmol) in CH2Cl2 (40 mL) and MeOH (20 mL) at −78° C. until the solution turned a deep blue. Excess ozone was blown off with oxygen. Methylsulfide (1 mL) was added followed by the addition of NaBH4 (0.22 g, 5.80 mmol) in 5% NaOH solution and methanol. The resulted mixture was stirred overnight at room temperature and washed with brine. The brine was then extracted with EtOAc (3×20 mL). The combined extracts were dried over Na2SO4. The desired product (0.36 g, 65% yield) was obtained as a colorless glass after SiO2 chromatography (5% MeOH/CH2Cl2). IR (neat) 3396, 3056, 2927, 1596, 1492, 1462, 1448, 1379, 1347, 1264, 1071 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.46-7.42 (m, 6 H), 7.32-7.18 (m, 9 H), 3.77-3.57 (series of multiplets, 10 H) 3.48-3.44 (m, 2 H), 3.36-3.30 (m, 2 H), 3.26-3.20 (m, 1 H), 3.04-2.99 (m, 2 H), 2.37-0.95 (series of multiplets, 27 H), 0.92 (s, 3 H), 0.91 (d, J=6.59 Hz, 3 H), 0.67 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 144.69, 128.87, 127.84, 126.94, 86.44, 81.05, 76.86, 74.65, 69.91, 69.22, 68.77, 64.24, 62.44, 62.42, 62.26, 46.92, 46.54, 42.87, 39.73, 36.86, 35.52, 35.13, 32.82, 32.54, 30.36, 28.71, 27.61, 27.44, 26.79, 24.82, 23.51, 23.38, 23.31, 18.28, 12.74; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 791.4844 (96.4%), calcd. 791.4863. Compound 37: NEt3 (0.23 mL, 1.66 mmol) was added to a solution of 36 (0.364 g, 0.47 mmol) in dry CH2Cl2 (30 mL) at 0° C. under N2 followed by the introduction of mesyl chloride (0.12 mL, 1.56 mmol). The mixture was stirred for 10 minutes and H2O (10 mL) added to quench the reaction, followed by extraction with EtOAc (3×30 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. SiO2 chromatography (EtOAc/hexanes 1:1) gave the desired product (0.41 g, 86% yield) as white glass. IR (neat) 3058, 3029, 2939, 2868, 1491, 1461, 1448, 1349, 1175, 1109, 1019 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.46-7.42 (m, 6 H), 7.31-7.19 (m, 9 H), 4.35-4.26 (m, 6 H), 3.84-3.74 (m, 2 H), 3.64-3.56 (m, 4 H), 3.49-3.34 (m, 3 H), 3.06 (s, 3 H), 3.04 (s, 3 H), 3.02 (s, 3 H), 3.09-2.95 (m, 2 H), 2.28 (bt, J=14.89 Hz, 1 H), 2.09-0.86 (series of multiplets, 21 H), 0.92 (s, 3 H), 0.90 (d, J=6.78 Hz, 3 H), 0.66 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 144.66, 128.86, 127.86, 126.97, 86.46, 81.28, 77.18, 75.00, 70.14, 69.89, 69.13, 66.49, 65.85, 65.72, 64.22, 47.06, 46.35, 42.77, 39.58, 37.81, 37.64, 37.55, 36.75, 35.48, 35.02, 32.59, 32.52, 30.27, 28.43, 27.56, 27.52, 26.92, 24.62, 23.34, 23.25, 23.10, 18.24, 12.64; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 1025.4207 (100%), calcd. 1025.4189. Compound 38: The suspension of 37 (0.227 g, 0.227 mmol) and NaN3 (0.147 g, 2.27 mmol) in dry DMSO (5 mL) was stirred at 80° C. overnight, diluted with H2O (50 mL) and extracted with EtOAc (3×20 mL). The extracts were washed with brine once and dried over anhydrous Na2SO4. SiO2 chromatography (EtOAc/hexanes 1:8) afforded the desired product (0.153 g, 80% yield) as a yellow oil. IR (neat) 2929, 2866, 2105, 1490, 1466, 1448, 1107, 705 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.46-7.42 (m, 6 H), 7.32-7.19 (m, 9 H), 3.80-3.74 (m, 1 H), 3.70-3.55 (series of multiplets, 5 H), 3.41-3.19 (series of multiplets, 9 H), 3.04-2.98 (m, 2 H), 2.41 (td, J=13.1, 2.44 Hz, 1 H), 2.29-2.14 (m, 2 H), 2.04-0.86 (series of multiplets, 20 H), 0.93 (s, 3 H), 0.91 (d, J=6.60 Hz, 3 H), 0.66 (s, 3. H); 13C NMR (CDCl3, 75 MHz) δ 144.78, 128.93, 127.87, 126.96, 86.46, 81.30, 77.16, 75.21, 67.99, 67.44, 67.03, 64.41, 51.64, 51.57, 51, 33, 46.71, 46.30, 42.35, 39.75, 36.72, 35.64, 35.20, 32.52, 32.42, 30.17, 28.63, 27.80, 27.22, 26.90, 24.80, 23.55, 23.30, 23.24, 18.23, 12.65; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 866.5049 (96.9%), calcd. 866.5057. Compound 39: p-Toluenesulfonic acid (1.72 mg) was added into the solution of 38 (0.153 g, 0.18 mmol) in CH2Cl2 (5 mL) and MeOH (5 mL), and the mixture was stirred for 2.5 hours. Saturated NaHCO3 solution (5 mL) was introduced followed by the introduction of brine (30 mL). The aqueous mixture was extracted with EtOAc and the combined extracts washed with brine and dried over Na2SO4. The desired product (0.10 g, 92% yield) was obtained as a pale yellowish oil after SiO2 chromatography (EtOAc/hexanes 1:3). IR (neat) 3426, 2926, 2104, 1467, 1441, 1347, 1107 cm−1; 1H NMR (CDCl3, 300 MHz) δ 3.81-3.74 (m, 1 H), 3.71-3.54 (m, 7 H), 3.41-3.19 (m, 9 H), 2.41 (td, J=13.61, 2.32 Hz, 1 H), 2.30-2.14 (m, 2 H), 2.07-1.98 (m, 1 H), 1.94-0.95 (series of multiplets, 21 H), 0.95 (d, J=6.35 Hz, 3 H), 0.93 (s, 3 H), 0.69 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 81.22, 77.08, 75.13, 67.94, 67.36, 66.97, 63.76, 51.59, 51.51, 51.26, 46.51, 46.24, 42.31, 39.68, 36.64, 35.58, 35.12, 32.34, 31.92, 30.11, 29.55, 28.54, 27.82, 27.16, 24.75, 23, 47, 23.23, 23.18, 18.15, 12.56; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 624.3966 (54.9%), calcd. 624.3962. Compound 40: To a solution of 39 (0.10 g, 0.166 mmol) in CH2Cl2 (8 mL) at 0° C. was added NEt3 (34.8 μL, 0.25 mmol) under N2 followed by the introduction of mesyl chloride (15.5 μL, 0.199 mmol). The mixture was stirred 15 minutes. Addition of H2O (3 mL) and brine (20 mL) was followed by extraction with EtOAc (4×10 mL). The combined extracts were washed with brine once and dried over Na2SO4. After removal of solvent, the residue was mixed with N-benzylmethylamine (0.5 mL) and heated to 80° C. under N2 overnight. Excess N-benzyl methylamine was removed in vacuo and the residue was subjected to SiO2 chromatography (EtOAc/hexanes 1:4) to give the product (0.109 g, 93% yield) as a yellow oil. IR (neat) 2936, 2784, 2103, 1467, 1442, 1346, 1302, 1106, 1027 cm−1; 1H NMR (CDCl3, 300 MHz) δ 7.32-7.23 (m, 5 H), 3.81-3.74 (m, 1 H), 3.71-3.55 (m, 5 H), 3.47 (s, 2 H), 3.41-3.19 (m, 9 H), 2.46-2.11 (m, 5 H), 2.18 (s, 3H), 2.03-0.85 (series of multiplets, 20 H), 0.93 (s, 3 H), 0.93 (d, J=6.35 Hz, 3 H,), 0.67 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 139.54, 129.26, 128.32, 126.97, 81.26, 77.12, 75.17, 67.98, 67.42, 67.00, 62.50, 58.41, 51.61, 51.54, 51.29, 46.66, 46.28, 42.46, 42.32, 39.72, 36.68, 35.76, 35.16, 33.75, 32.38, 30.15, 28.59, 27.85, 27.19, 24.77, 24.15, 23.53, 23.28, 23.22, 18.28, 12.60; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 705.4929 (100%), calcd. 705.4928. Compound 8: A suspension of 40 (0.109 g, 0.155 mmol) and LiAlH4 (23.5 mg, 0.62 mmol) in THF (20 mL) was stirred under N2 overnight. Na2SO4 10 H2O was carefully added and stirred until no grey color persisted. Anhydrous Na2SO4 was added and the white precipitate was filtered out and rinsed with dry THF. After removal of solvent, the residue was dissolved in minimum CH2Cl2 and filtered. The desired product (0.091 g, 94% yield) was obtained as a colorless oil after the solvent was removed. IR (neat) 3371, 3290, 3027, 2938, 2862, 2785, 1586, 1493, 1453, 1377, 1347, 1098 cm−1; 1H NMR (CDCl3, 300 MHz)_b 7.31-7.21 (m, 5 H), 3.65-3.53 (m, 4 H), 3.47 (s, 2 H), 3.42-3.34 (m, 2 H), 3.30 (bs, 1 H), 3.26-3.20 (m, 1 H), 3.14-3.09 (m, 1 H), 2.89-2.81 (m, 6 H), 2.39-2.27 (m, 3 H), 2.17 (s, 3 H), 2.15-0.88 (series of multiplets, 29 H), 0.93 (d, J=6.59 Hz, 3 H), 0.92 (s, 3 H), 0.67 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 139.34, 129.16, 128.24, 126.90, 80.75, 76.44, 74.29, 70.58, 69.88, 69.75, 62.47, 58.27, 46.66, 46.47, 42.75, 42.63, 42.51, 42.35, 39.77, 36.87, 35.73, 35.04, 33.77, 32.90, 30.38, 28.71, 27.70, 27.32, 24.89, 24.09, 23.53, 23.36, 23.25, 18.24, 12.62; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 627.5199 (23.3%), calcd. 627.5213. Compound 9: To a solution of 23 (0.18 g, 0.28 mmol) in dry DMF (4 mL) were added NaH (0.224 g, 60% in mineral oil, 5.60 mmol) and 1-bromo octane (0.48 mL, 2.80 mmol). The suspension was stirred under N2 at 65° C. overnight followed by the introduction of H2O (60 mL) and extraction with ether (4×20 mL). The combined extracts were washed with brine and dried over Na2SO4. SiO2 chromatography (hexanes and 5% EtOAc in hexanes) afforded the desired product (0.169 g, 80% yield) as a pale yellowish oil. IR (neat) 2927, 2865, 2099, 1478, 1462, 1451, 1350, 1264, 1105 cm−1; 1H NMR (CDCl3, 300 MHz) δ 3.69-3.35 (series of multiplets, 15 H), 3.26-3.02 (series of multiplets, 4 H), 2.19-2.02 (m, 3 H), 1.97-1.16 (series of multiplets, 37 H), 1.12-0.99 (m, 2 H), 0.92-0.86 (m, 9 H), 0.65 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.69, 79.84, 76.13, 71.57, 71.15, 65.07, 64.49, 64.39, 49.08, 48.99, 48.80, 46.68, 46.45, 42.72, 42.05, 39.88, 35.74, 35.49, 35.36, 35.14, 32.42, 32.03, 30.01, 29.85, 29.81, 29.76, 29.67, 29.48, 29.14, 27.92, 27.80, 27.70, 26.58, 26.42, 23.59, 23.09, 22.92, 22.86, 18.11, 14.31, 12.65, HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 778.5685 (22.1%), calcd. 778.5683. The triazide (0.169 g, 0.224 mmol) and LiAlH4 (0.025 g, 0.67 mmol) were suspended in anhydrous THF (10 mL) and stirred under N2 at room temperature overnight followed by careful introduction of Na2SO4 hydrate. After the grey color disappeared, anhydrous Na2SO4 was added and stirred. The white precipitate was removed by filtration and washed with TBF. After removal of solvent, the residue was dissolved in 1 M hydrochloric acid and the aqueous solution was extracted with ether (5 mL) once. The aqueous solution was then made basic by adding 20% aqueous NaOH solution followed by extraction with Et2O (4×5 mL). The combined extracts were washed, dried and concentrated. The residue was then subject to SiO2 chromatography (MeOH/CH2Cl2 (1:1) followed by MeOH/CH2Cl2/NH3.H2O (4:4:1)) to afford the desired product (0.091 g, 60% yield) as a colorless oil. IR (neat) 3361, 2927, 2855, 1576, 1465, 1351, 1105 cm−1; 1H NMR (CD3OD, 300 MHz) δ 4.86 (bs, 6 H), 3.77-3.72 (m, 1 H), 3.70-3.61 (m, 1 H), 3.57-3.53 (m, 3 H), 3.43-3.38 (m, 4 H), 3.34-3.27 (m, 2 H), 3.18-3.10 (m, 2 H), 2.84-2.71 (m, 6 H), 2.22-2.07 (m, 3 H), 2.00-1.02 (series of multiplets, 39 H), 0.97-0.88 (m, 9 H), 0.71 (s, 3 H); 13C NMR (CD3OD, 75 MHz) δ 82.20, 81.00, 77.62, 72.52, 72.06, 68.00, 67.92, 67.39, 48.20, 47.53, 44.26, 43.40, 41.42, 41.15, 40.84, 40.35, 36.88, 36.73, 36.42, 36.11, 34.24, 34.05, 33.94, 33.67, 33.17, 30.95, 30.72, 30.62, 29.81, 29.35, 28.87, 28.79, 27.51, 24.57, 23.90, 23.83, 23.44, 18.76, 14.62, 13.07; HRFAB-MS (thioglycerol matrix) m/e: ([M+H]+) 678.6133 (100%), calcd. 678.6149. Compound 10: A suspension of 23 (0.126 g, 0.196 mmol) and LiAlH4 (0.037 g, 0.98 mmol) in THF (40 mL) was stirred at room temperature under N2 overnight followed by careful addition of Na2SO4.10 H2O. After the grey color in the suspension disappeared, anhydrous Na2 SO4 was added and stirred until organic layer became clear. The white precipitate was removed by filtration and washed with twice THF. The THF was removed in vacuo, and the residue was subject to SiO2 chromatography (MeOH/CH2Cl2/NH3.H2O (4:4:1)) to afford the desired product (0.066 g, 60% yield) as a colorless oil. IR (neat) 3365, 2933, 2865, 1651, 1471, 1455, 1339, 1103 cm−1; 1H NMR (CDCl3/30% CD3OD, 300 MHz) δ 4.43 (bs, 7 H), 3.74-3.68 (m, 1 H), 3.66-3.60 (m, 1H), 3.57-3.50 (m, 5 H), 3.34-3.25 (M, 2 H), 3.17-3.06 (M, 2 H), 2.84-2.74 (M, 6 H), 2.19-2.01 (M, 3 H), 1.97-0.96 (series of multiplets, 27 H), 0.94 (d, J=7.2 Hz, 3 H), 0.92 (s, 3 H), 0.69 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.44, 79.27, 75.77, 66.59, 66.53, 65.86, 62.51, 46.21, 45.84, 42.55, 41.53, 40.09, 39.43, 39.31, 39.02, 35.16, 34.93, 34.86, 34.57, 32.93, 32.71, 31.57, 28.66, 28.33, 27.64, 27.22, 23.04, 22.40, 22.29, 17.60, 11.98; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 566.4889 (8.9%), calcd. 566.4897. Example 5 Syntheses of Compounds 11 and 43-47 Compound 43: Compound 41 was prepared following the method reported by D. H. R. Barton, J. Wozniak, S. Z. Zard, A SHORT AND EFFICIENT DEGRADATION OF THE BILE ACID SIDE CHAIN. SOME NOVEL REACTIONS OF SULPHINES AND A-KETOESTERS, Tetrahedron, 1989, vol. 45, 3741-3754. A mixture of 41 (1.00 g, 2.10 mmol), ethylene glycol (3.52 mL, 63 mmol) and p-TsOH (20 mg, 0.105 mmol) was refluxed in benzene under N2 for 16 hours. Water formed during the reaction was removed by a Dean-Stark moisture trap. The cooled mixture was washed with NaHCO3 solution (50 mL) and extracted with Et2O (50 mL, 2×30 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. Removal of the solvent gave the product (1.09 g, 100%) as a white glass. IR (neat) 2939, 2876, 1735, 1447, 1377, 1247, 1074, 1057, 1039 cm−1; 1H NMR (CDCl3, 300 MHz) δ 5.10 (t, J=2.70 Hz, 1 H), 4.92 (d, J=2.69 Hz, 1 H), 4.634.52 (m, 1 H), 3.98-3.80 (m, 4 H), 2.32 (t, J=9.51 Hz, 1H), 2.13 (s, 3 H), 2.08 (s, 3 H); 2.05 (s, 3 H), 2.00-1.40 (series of multiplets, 15 H), 1.34-0.98(m, 3 H), 1.20(s, 3 H), 0.92(s, 3 H), 0.82(s, 3 H); 13C NMR(CDCl3, 75 MHz) 170.69, 170.63, 170.47, 111.38, 75.07, 74.23, 70.85, 64.95, 63.43, 49.85, 44.73, 43.39, 41.11, 37.37, 34.84, 34.80, 34.52, 31.42, 29.18, 27.02, 25.41, 24.16, 22.72, 22.57, 22.44, 21.73, 21.63, 13.40; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 521.3106 (38.6%), calcd. 521.3114. The triacetate (1.09 g, 2.10 mmol) was dissolved in MeOH (50 mL). NaOH (0.84 g, 21 mmol) was added to the solution. The suspension was then refluxed under N2 for 24 hours. MeOH was then removed in vacuo and the residue was dissolved in Et2O (100 mL) and washed with H2O, brine, and then dried over anhydrous Na2SO4. The desired product (0.80 g, 96% yield) was obtained as white solid after removal of solvent. m.p. 199-200° C. IR (neat) 3396, 2932, 1462, 1446, 1371, 1265, 1078, 1055 cm−1; 1H NMR (10% CD3OD in CDCl3, 300 MHz) δ 4.08-3.83 (series of multiplets, 9 H), 3.44-3.34 (m, 1 H), 2.41 (t, J=9.28 Hz, 1 H), 2.22-2.10 (m, 2 H), 1.96-1.50 (series of multiplets, 12 H), 1.45-0.96 (series of multiplets, 4 H), 1.32 (s, 3 H) 0.89 (s, 3 H), 0.78 (s, 3 H); 13C NMR (10% CD3OD in CDCl3, 75 MHz) δ 112.11, 72.35, 71.57, 68.09, 64.54, 63.24, 49.36, 45.90, 41.48, 41.45, 39.18, 38.79, 35.29, 34.71, 34.45, 29.90, 27.26, 26.60, 23.65, 22.54, 22.44, 22.35, 13.46; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 417.2622 (87.3%), calcd. 417.2617. Compound 44: To a round-bottom flask were added 43 (0.80 g, 2.03 mmol) and dry THF (100 mL) followed by the addition of NaH (60% in mineral oil, 0.81 g, 20.3 mmol). The suspension was refluxed under N2 for 30 minutes before the addition of allyl bromide (1.75 mL, 20.3 mmol). After 48-hours of reflux, another 10 eq. of NaH and allyl bromide were added. After another 48 hours, TLC showed no intermediates left. Cold water (50 mL) was added to the cooled suspension. The resulted mixture was extracted with Et2O (60 mL, 2×30 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. SiO2 column chromatography (6% EtOAc in hexanes) gave the desired product (0.94 g, 90% yield) as a pale yellow oil. IR (neat) 3076, 2933, 2866, 1645, 1446, 1423, 1408, 1368, 1289, 1252, 1226, 1206, 1130, 1080, 1057 cm−1; 1H NMR (CDCl3, 300 MHz) δ 6.02-5.84 (m, 3 H), 5.31-5.04 (m, 6 H), 4.12-4.05 (m, 2 H), 4.01-3.81 (m, 7 H), 3.70 (dd, J=12.94, 5.62 Hz, 1 H), 3.55 (t, J=2.56 Hz, 1 H), 3.33 (d, J-=2.93 Hz, 1 H), 3.18-3.08 (m, 1 H), 2.65 (t, J=10.01 Hz, 1 H), 2.32-2.14 (m, 3 H), 1.84-1.45 (series of multiplets, 10 H), 1.41-1.22 (m, 3 H), 1.27 (s, 3 H), 1.14-0.92 (m, 2 H), 0.89 (s, 3 H), 0.75 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 136.38, 136.07, 136.00, 116.31, 115.54, 115.38, 112.34, 80.07, 79.22, 75.05, 69.83, 69.34, 68.82, 65.14, 63.24, 48.80, 45.96, 42.47, 42.15, 39.40, 35.55, 35.16, 35.15, 29.04, 28.22, 27.52, 24.21, 23.38, 23.11, 22.95, 22.58, 13.79; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 537.3549 (100%), calcd. 537.3556. Compound 45: To the solution of 44 (0.94 g, 1.83 mmol) in dry THF (50 mL) was added 9-BBN (0.5 M solution in THF, 14.7 mL, 7.34 mmol) and the mixture was stirred under N2 at room temperature for 12 hours before the addition of 20% NaOH solution (4 mL) and 30% H2O2 solution (4 mL). The resulted mixture was then refluxed for an hour followed by the addition of brine (100 mL) and extracted with EtOAc (4×30 mL). The combined extracts were dried over anhydrous Na2SO4. After the removal of solvent, the residue was purified by SiO2 column chromatography (EtOAc followed by 10% MeOH in CH2Cl2) to give the product (0.559 g, 54% yield) as a colorless oil. IR (neat) 3410, 2933, 2872, 1471, 1446, 1367, 1252, 1086 cm−1; 1H NMR (CDCl3, 300 MHz) δ 4.02-3.52 (series of multiplets, 17 H), 3.41-3.35 (m, 1 H), 3.29 (d, J=2.44 Hz, 1H), 3.22-3.15 (m, 3 H), 2.58 (t, J=10.01 Hz, 1 H), 2.27-1.95 (m, 3 H), 1.83-1.48 (series of multiplets, 16 H), 1.40-0.93 (series of multiplets, 5 H), 1.27 (s, 3 H), 0.90 (s, 3 H), 0.75 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 112.41, 80.09, 79.09, 76.31, 66.70, 66.02, 65.93, 64.80, 63.26, 61.53, 61.25, 60.86, 48.59, 45.80, 42.51, 41.72, 39.10, 35.36, 35.02, 34.98, 32.87, 32.52, 32.40, 28.88, 27.94, 27.21, 24.33, 23.02, 22.84 (2 C's), 22.44, 13.69; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 591.3881 (100%), calcd. 591.3873. Compound 46: To a solution of 45 (0.559 g, 0.98 mmol) in acetone (40 mL) and water (4 mL) was added PPTS (0.124 g, 0.49 mmol) and the solution was refluxed under N2 for 16 hours. The solvent was removed under reduced pressure. Water (40 mL) was then added to the residue and the mixture was extracted with EtOAc (40 mL, 2×20 mL). The combined extracts were washed with brine, dried and evaporated to dryness. SiO2 column chromatography (8% MeOH in CH2Cl2) of the residue afforded the desired product (0.509 g, 98% yield) as clear oil. IR (neat) 3382, 2941, 2876, 1699, 1449, 1366, 1099 cm−1; 1H NMR (CDCl3, 300 MHz) δ 3.83-3.72 (m, 8 H), 3.66 (t, J=5.62 Hz, 2 H), 3.54 (bs, 2 H), 3.43-3.28 (m, 4 H), 3.24-3.12 (m, 2 H), 2.26-2.00 (m, 4 H), 2;08 (s, 3 H), 1.98-1.50 (series of multiplets, 15 H), 1.42-0.96 (series of multiplets, 6 H), 0.90 (s, 3 H), 0.62 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 210.49, 78.87 (2 C's), 76.30, 66.86, 66.18, 65.69, 61.74, 61.43, 60.71, 55.31, 48.05, 43.02, 41.58, 39.53, 35.28, 35.09, 34.96, 32.77, 32.70, 32.31, 31.12, 28.72, 27.88, 27.14, 23.47, 22.75, 22.47, 22.34, 13.86; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 547.3624 (100%), calcd. 547.3611. Compound 47: To a solution of 46 (0.18 g, 0.344 mmol) in dry CH2Cl2 (10 mL) at 0° C. was added Et3N (0.168 mL, 1.20 mmol) followed by the addition of mesyl chloride (0.088 mL, 1.13 mmol). After 10 minutes, H2O (3 mL) and brine (30 mL) were added. The mixture was extracted with EtOAc (30 mL, 2×10 mL) and the extracts were washed with brine and dried over anhydrous Na2SO4. After removal of solvent, the residue was dissolved in DMSO (5 mL) and NaN3 (0.233 g, 3.44 mmol). The suspension was heated up to 50° C. under N2 for 12 hours. H2O (50 mL) was added to the cool suspension and the mixture was extracted with EtOAc (30 mL, 2×10 mL) and the extracts were washed with brine and dried over anhydrous Na2SO4. SiO2 column chromatography (EtOAc/hexanes 1:5) afforded the product (0.191 g, 88% yield for two steps) as a pale yellow oil. IR (neat) 2933, 2872, 2096, 1702, 1451, 1363, 1263, 1102 cm−1; 1H NMR (CDCl3, 300 MHz). δ 3.72-3.64 (m, 2 H), 3.55-3.24 (series of multiplets, 11 H), 3.18-3.02 (m, 2 H), 2.22-2.02 (m, 4 H), 2.08 (s, 3 H), 1.95-1.46 (series of multiplets, 15 H), 1.38-0.96 (series of multiplets, 6 H), 0.89 (s, 3 H), 0.62 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 210.36, 79.69, 79.22, 75.98, 65.08, 64.80, 64.53, 55.31, 48.93, 48.86, 48.76, 48.06, 43.03, 41.91, 39.66, 35.44, 35.31, 35.12, 31.04, 29.77, 29.69, 29.67, 28.99, 28.10, 27.65, 23.60, 22.99, 22.95, 22.50, 14.00; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 622.3820 (100%), calcd. 622.3805. Compound 11: Compound 47 (0.191 g, 0.319 mmol) was dissolved in dry ThF (20 mL) followed by the addition of LiAlH4 (60.4 mg, 1.59 mmol). The grey suspension was stirred under N2 at room temperature for 12 hours. Na2SO4.10H2O powder was carefully added. After the grey color in the suspension disappeared, anhydrous Na2SO4 was added and the precipitate was filtered out. After the removal of solvent, the residue was purified by column chromatography (silica gel, MeOH/CH2Cl2/28% NH3—H2O 3:3:1). After most of the solvent was rotavapped off from the fractions collected, 5% HCl solution (2 mL) was added to dissolve the milky residue. The resulted clear solution was then extracted with Et2O (2×10 mL). 20% NaOH solution was then added until the solution became strongly basic. CH2Cl2 (20 mL, 2×10 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4 and removal of solvent gave the desired product (0.115 g, 69% yield) as a colorless oil. From 1H NMR it appears that this compound was a mixture of two stereoisomers at C20 with a ratio of approximately 9:1. The stereoisomers were not separated, but used as recovered. Spectra for the most abundant isomer: IR (neat) 3353, 2926, 2858, 1574, 1470, 1366, 1102 cm−1; 1H NMR (20% CDCl3 in CD3OD, 300 MHz) δ 4.69 (bs, 7 H), 3.76-3.69 (m, 1 H), 3.63-3.53 (m, 5 H), 3.50-3.40 (m, 1 H), 3.29 (bs, 1 H), 3.18-3.07 (m, 2 H), 2.94-2.83 (m, 1 H), 2.81-2.66 (m, 5 H), 2.23-2.06 (m, 4 H), 1.87-1.50 (series of multiplets, 15 H), 1.39-0.96 (series of multiplets, 6 H), 1.11 (d, J=6.10 Hz, 3 H), 0.93 (s, 3 H), 0.75 (s, 3 H); 13C NMR (20% CDCl3 in CD3OD, 75 MHz) δ 81.46, 80.67, 77.32, 70.68, 67.90, 67.66, 67.18, 50.32, 47.17, 43.30, 43.06, 40.74, 40.64, 40.38, 40.26, 36.31, 36.28, 35.93, 34.30, 34.02, 33.29, 29.63, 29.31, 28.43, 26.10, 24.67, 24.09, 23.96, 23.50, 13.30 for the major isomer; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 524.4431 (64.2%), calcd. 524.4427. Example 6 Syntheses of Compounds 12, 48 and 49 Compound 48: To a solution of 23 (0.15 g, 0.233 mmol) in dq CH2Cl2 (15 mL) at 0° C. was added Et3N (48.8 μL, 0.35 mmol) followed by the addition of CH3SO2Cl (21.7 μL, 0.28 mmol). The mixture was stirred for 15 minutes before H2O (3 mL) was added. Saturated NaCl solution (20 mL) was then added, and the mixture was extracted with EtOAc (40 mL, 2×20 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. The solvent was rotovapped off and to the residue were added NaBr (0.12 g, 1.17 mmol) and DMF (10 mL). The suspension was heated up to 80° C. under N2 for 2 hours. DMF was removed under vacuum and the residue was chromatographed on silica (EtOAc/hexanes 1:10) to give the desired product (0.191 g, 97% yield) as a pale yellow oil. 1H NMR (CDCl3, 300 MHz) δ 3.69-3.35 (series of multiplets, 13 H), 3.28-3.02 (series of multiplets, 4 H), 2.18-2.04 (m, 3 H), 2.00-1.60 (series of multiplets, 16 H), 1.58-0.96 (series of multiplets, 11 H), 0.92 (d, J=6.34 Hz, 3H), 0.89 (s, 3 H), 0.66 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.62, 79.81, 76.08, 65.07, 64.50, 64.34, 49.03, 48.98, 48.79, 46.49, 46.46, 42.73, 42.02, 39.85, 35.47, 35.34, 35.12, 34.79, 34.72, 29.82, 29.80, 29.74, 29.11, 27.91, 27.78, 27.69, 23.55, 23.07, 22.88, 18.10, 12.62; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M−H]+) 706.3609 (63.1%), calcd. 706.3591; 704.3616 (52.8%), calcd. 704.3611. Compound 49: Compound 48 (0.191 g, 0.269 mmol) and 23 (0.295 g, 0.459 mmol) was dissolved in DMF (3 mL, distilled over BaO at 6 mm Hg before use) followed by the addition of NaH (0.054 g, 60% in mineral oil). The suspension was stirred under N2 at room temperature for 24 hours. H2O (100 mL) was added to quench excess NaH and the mixture was then extracted with Et2O (40 mL, 3×20 mL) and the combined extracts were washed with brine and dried over anhydrous Na2SO4. The desired product (0.177 g, 52% yield based on compound 23) was obtained as a pale yellow oil after SiO2 chromatography (EtOAc/hexanes 1:6, then 1:2). IR (neat) 2940, 2862, 2095, 1472, 1456, 1362, 1263, 1113 cm−1; 1H NMR(CDCl3, 300 MHz) δ 3.68-3.35 (series of multiplets, 26 H), 3.28-3.02 (series of multiplets, 8 H), 2.20-2.04 (m, 6 H), 1.96-1.60 (series of multiplets, 30 H), 1.52-0.98 (series of multiplets, 12 H), 0.91 (d, J=6.59 Hz, 6 H), 0.89 (s, 6 H), 0.65 (s, 6 H); 13C NMR(CDCl3, 75 MHz) δ 80.68, 79.83, 76.13, 71.71, 65.06, 64.48, 64.39, 49.08, 48.98, 48.80, 46.64, 46.44, 42.71, 42.04, 39.88, 35.73, 35.49, 35.36, 35.14, 32.41, 29.84, 29.81, 29.76, 29.14, 27.92, 27.78, 27.69, 26.58, 23.59, 23.08, 22.92, 18.12, 12.64. Compound 12: Compound 49 (0.219 g, 0.173 mmol) was dissolved in dry THF (10 mL) followed by the addition of LiAlH4 (65 mg, 1.73 mmol). The grey suspension was stirred under N2 at room temperature for 12 hours. Na2SO4.10H2O powder was carefully added. After the grey color in the suspension disappeared, anhydrous Na2SO4 was added and the precipitate was filtered out. After the removal of solvent, the residue was purified by column chromatography (silica gel, MeOH/CH2Cl2/28% NH3H2O 2.5:2.5:1). After most of the solvent was rotavapped off from the fractions collected, 5% HCl solution (2 mL) was added to dissolve the milky residue. The resulted clear solution was then extracted with Et2O (2×10 mL). 20% NaOH solution was then added until the solution became strongly basic. CH2Cl2 (20 mL, 2×10 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4 and removal of solvent gave the desired product (0.147 g, 76% yield) as a white glass. IR (neat) 3364, 3287, 2934, 2861, 1596, 1464, 1363, 1105 cm−1; 1H NMR (20% CDCl3 in CD3OD, 500 MHz) δ 4.74 (bs, 12 H), 3.75-3.70 (m, 2 H), 3.65-3.61 (m, 2 H), 3.57-3.52 (m, 6 H), 3.40 (t, J=3.60 Hz, 4 H), 3.30 (bs, 4 H), 3.16-3.10 (m, 4 H), 2.84-2.73 (m, 12 H), 2.18-2.07 (m, 6 H), 1.97-1.61 (series of multiplets, 30 H), 1.58-0.98 (series of multiplets, 24 H), 0.95 (d, J=6.84 Hz, 6 H), 0.94 (s, 6 H), 0.70 (s, 6 H); 13C NMR (20% CDCl3 in CD3OD, 125 MHz) δ 81.70, 80.52, 77.09, 72.34, 67.75 (2 C's), 67.07, 47.80, 47.13, 43.76, 42.87, 41.20, 40.65, 40.58, 40.14, 36.43, 36.25, 36.08, 35.77, 34.15, 33.87 (2 C's), 33.18, 29.55, 28.92, 28.47, 28.42, 27.25, 24.27, 23.54, 23.41, 18.70, 13.07; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 1113.9625 (68.8%), calcd. 1113.9610. Example 7 Syntheses of Compounds 111-113 and 116 a-d Compounds 116a-d: Representative procedure: preparation of 116b. NaH (0.06 g, 60% in mineral oil, 1.49 mmol) and propyl bromide (0.136 mL, 1.49 mmol) were added to a DMF solution of compound 23 (described in Li et al., J. Am. Chem. Soc. 1998, 120, 2961) (0.096 g, 0.149 mmol). The suspension was stirred under N2 for 24 hr. H2O (20 mL) was added, and the mixture was extracted with hexanes (3×10 mL). The combined extracts were dried over Na2SO4 and concentrated in vacuo. Silica gel chromatography (10% EtOAc in hexanes) afforded the desired product (92 mg, 90% yield) as a pale yellow oil. 1H NMR (CDCl3, 500 MHz) δ 3.68-3.64 (m, 1 H), 3.61-3.57 (m, 1 H), 3.52 (t, J=6.1 Hz, 2 H), 3.49 (bs, 1 H), 3.46-3.35 (m, 10 H), 3.25 (d, J=2.4 Hz, 1 H), 3.23-3.19 (m, 1 H), 3.16-3.11 (m, 1 H), 3.09-3.03 (m, 1 H), 2.17-2.03 (m, 3 H), 1.95-1.55 (m, 17 H), 1.51-1.40 (m, 4 H), 1.38-1.17 (m, 5 H), 1.11-0.96 (m, 3 H), 0.93-0.89 (m, 9 H), 0.65 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.64, 79.79, 76.08, 72.67, 71.59, 65.01, 64.44, 64.33, 49.04, 48.94, 48.75, 46.61, 46.40, 42.68, 42.00, 39.83, 35.72, 35.45, 35.30, 35.10, 32.38, 29.81, 29.77, 29.72, 29.09, 27.88, 27.76, 27.65, 26.52, 23.55, 23.12, 23.04, 22.87, 18.06, 12.60, 10.79; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 708.4910 (23.5%), calcd. 708.4920. Compounds 111-113: Representative procedure: preparation of 112. Compound 116b (0.092 g, 0.134 mmol) was dissolved in THF (10 mL) followed by the addition of LiAlH4 (0.031 g, 0.81 mmol). The suspension was stirred under N2 for 12 hr. Na2SO4.10H2O (˜1 g) was then carefully added. After the gray color in the suspension dissipated, anhydrous Na2SO4 was added, and the precipitate was removed by filtration. Concentration and silica gel chromatography (CH2Cl2/MeOH/28% NH3.H2O 12:6:1, then 10:5:1) yielded a glass which was dissolved in 1 M HCl (2 mL). The resulting clear solution was washed with Et2O (2×10 mL). 20% NaOH solution was added to the aqueous phase until the solution became strongly basic. CH2Cl2 (3×10 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4 and concentrated in vacuo to give the desired product (0.045 g, 55% yield) as a white glass. 112: 1H NMR (˜20% CDCl3 in CD3OD, 500 MHz) δ 4.73 (bs, 6 H), 3.74-3.70 (m, 1 H), 3.65-3.61 (m, 1 H), 3.55 (t, J=6.3 Hz, 2 H), 3.42-3.38 (m, 4 H), 3.33-3.30 (m, 2 H), 3.16-3.10 (m, 2 H), 2.83-2.73 (m, 6 H), 2.18-2.06 (m, 3 H), 1.96-1.20 (series of multiplets, 26 H), 1.12-0.98 (m, 3 H), 0.95-0.92 (m, 9 H), 0.70 (s, 3 H); 13C NMR (˜20% CDCl3 in CD3OD, 75 MHz) δ 81.67, 80.49, 77.04, 73.44, 72.28, 67.77, 67.71, 67.06, 47.74, 47.08, 43.75, 42.82, 41.21, 40.60, 40.56, 40.12, 36.47, 36.19, 36.04, 35.74, 34.09, 33.82, 33.78, 33.16, 29.49, 28.87, 28.43, 27.18, 24.22, 23.66, 23.49, 23.40, 18.64, 13.04, 11.03; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 608.5348 (100%), calcd. 608.5330. 111: 1H NMR (˜20% CDCl3 in CD3OD, 500 MHz) δ 4.79 (bs, 6 H), 3.74-3.71 (m, 1 H), 3.66-3.62 (m, 1 H), 3.55 (t, J=6.1 Hz, 2 H), 3.52 (bs, 1 H), 3.38-3.28 (series of multiplets, 4 H), 3.33 (s, 3 H), 3.16-3.10 (m, 2H), 2.83-2.72 (m, 6 H), 2.19-2.07 (m, 3 H), 1.97-1.62 (series of multiplets, 15 H), 1.58-1.20 (series of multiplets, 9 H), 1.13-0.98 (m, 3 H), 0.95 (d, J=6.3 Hz, 3 H), 0.93 (s, 3 H), 0.70 (s, 3 H); 13C NMR (˜20% CDCl3 in CD3OD, 75 MHz) δ 81.82, 80.65, 77.20, 74.43, 67.85, 67.18, 58.90, 47.80, 47.22, 43.91, 43.01, 41.31, 40.78, 40.69, 40.22, 36.63, 36.35, 36.18, 35.86, 34.27, 33.97, 33.26, 29.60, 29.03, 28.58, 28.53, 27.14, 24.33, 23.61, 23.45, 18.68, 13.06; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 602.4855 (100%), calcd. 602.4873. 113: 1H NMR (˜50% CDCl3 in CD3OD, 500 MHz) δ 4.08 (bs, 6 H), 3.71-3.67 (m, 1 H), 3.62-3.58 (m, 1 H), 3.53 (t, J=6.3 Hz, 2 H), 3.49 (bs, 1 H), 3.43-3.38 (m, 4 H), 3.31-3.27 (m, 2 H), 3.14-3.07 (m, 2 H), 2.83-2.73 (m, 6 H), 2.16-2.03 (m, 3 H), 1.93-1.17 (series of multiplets, 30 H), 1.10-0.96 (m, 3 H), 0.93-0.89 (m, 9 H), 0.67 (s, 3 H); 13C NMR (˜50% CDCl3 in CD3OD, 75 MHz) δ 80.51, 79.35, 75.85, 71.29, 70.83, 66.73, 66.62, 65.96, 46.68, 45.98, 42.59, 41.63, 40.20, 39.53, 39.43, 39.21, 35.34, 35.04, 35.00, 34.71, 33.11, 32.90, 32.82, 32.00, 29.15, 28.49, 28.15, 27.75, 27.35, 26.22, 23.18, 22.60, 22.45, 22.34, 17.77, 13.75, 12.22; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 636.5679 (100%), calcd. 636.5669. Example 8 Syntheses of Compounds 106 and 124 Compound 124: Compound 47 (0.256 g, 0.489 mmol) was dissolved in CH2Cl2 (10 mL), and cooled to 0° C. followed by the addition of Na2HPO4 (0.69 g, 4.89 mmol) and urea-hydrogen peroxide complex (UHP) (0.069 g, 0.733 mmol). Trifluoroacetic anhydride (TFAA) (0.138 mL, 0.977 mmol) was then added dropwise. The suspension was stirred for 12 hr, and additional UHP (23 mg, 0.25 mmol) and TFAA (0.069 mL, 0.49 mmol) were added. After another 12 hr, H2O (30 mL) was added, and the resulting mixture was extracted with EtOAc (3×20 mL). The combined extracts were washed with brine (50 mL), dried over anhydrous Na2SO4, and concentrated in vacuo. SiO2 chromatography (EtOAc/hexanes 1:5) afforded the desired product (0.145 g, 55% yield) as a colorless oil. 1H NMR (CDCl3, 300 MHz) δ 5.21 (dd, J=9.3 and 7.3 Hz, 1 H), 3.70-3.57 (m, 2 H), 3.55 (t, J=6.0 Hz, 2 H), 3.43-3.37 (m, 6 H), 3.32-3.25 (m, 3 H), 3.17-3.02 (m, 2 H), 2.28-2.05 (m, 4 H), 2.03 (s, 3 H), 1.86-1.19 (series of multiplets, 19 H), 0.97 (dd, J=14.5 and 3.3 Hz, 1 H), 0.90 (s, 3 H), 0.78 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 171.08, 79.71, 78.03, 75.72, 75.53, 65.41, 65.04, 64.53, 48.79, 48.70, 46.49, 41.92, 39.44, 37.81, 35.45, 35.22, 35.10, 29.73, 29.63, 28.89, 28.33, 27.50, 27.34, 23.39, 22.97, 22.92, 21.28, 12.72; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M−H]+) 614.3798 (24.5%), calcd. 614.3778. Compound 106: Compound 124 (0.145 g, 0.236 mmol) was dissolved in CH2Cl2 (2 mL) and MeOH (1 mL). 20% NaOH solution (0.2 mL) was added. The mixture was stirred for 12 hr, and anhydrous Na2SO4 was used to remove water. After concentration in vacuo, the residue was purified by silica gel chromatography (EtOAc/hexanes 1:3) to afford the desired product (0.124 g, 92% yield) as a colorless oil. 1H NMR (CDCl3, 300 MHz) δ 4.29 (bs, 1 H), 3.69-3.60 (m, 2 H), 3.52 (t, J=6.0 Hz, 2 H), 3.45-3.32 (m, 8 H), 3.26 (d, J=2.7 Hz, 1 H), 3.17-3.02 (m, 2 H), 2.19-1.94 (m, 4 H), 1.90-1.62 (series of multiplets, 13 H), 1.57-1.20 (series of multiplets, 7 H), 0.97 (dd, J=14.3 and 3.1 Hz, 1H), 0.90 (s, 3 H), 0.73 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 79.69, 78.03, 75.47, 73.38, 65.46, 65.00, 64.47, 48.87, 48.68, 46.83, 41.93, 39.71, 37.87, 35.43, 35.20, 35.09, 29.96, 29.69, 29.59, 29.53, 28.89, 28.44, 27.48, 23.72, 22.91, 22.71, 11.77. The alcohol (0.124 g, 0.216 mmol) was dissolved in dry THF (20 mL) followed by the addition of LiAlH4 (33 mg, 0.866 mmol). The gray suspension was stirred under N2 for 12 hr. Na2SO4.10H2O (˜2 g) was carefully added. After the gray color in the suspension dissipated, anhydrous Na2SO4 was added and the precipitate was removed by filtration. After the removal of solvent, the residue was purified by column chromatography (SiO2, MeOH/CH2Cl2/28% NH3.H2O 2.5:2.5:1). After concentration of the relevant fractions, 1 M HCl (2 mL) was added to dissolve the milky residue. The resulting clear solution was washed with Et2O (2×10 mL). To the aqueous phase, 20% NaOH solution was added until the solution became strongly basic. CH2Cl2 (20 mL, 2×10 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4 and removal of solvent gave the desired product (0.050 g, 47% yield) as a colorless oil. 1H NMR (20% CDCl3 in CD3OD, 300 MHz) δ 4.77 (s, 7 H), 4.25 (t, J=8.5 Hz, 1 H), 3.75-3.68 (m, 1 H), 3.66-3.58 (m, 1 H), 3.55 (t, J=6.1 Hz, 2 H), 3.48-3.41 (m, 1 H), 3.34 (bs, 1 H), 3.30 (d, J=3.6 Hz, 1 H), 3.17-3.08 (m, 2 H), 2.86-2.70 (m, 6H), 2.20-1.91 (m, 4 H), 1.88-1.16 (series of multiplets, 19 H), 1.00 (dd, J-=14.2 and 3.0 Hz, 1 H), 0.93 (s, 3 H), 0.73 (s, 3 H); 13C NMR (20% CDCl3 in CD3OD, 75 MHz) δ 80.62, 79.12, 76.74, 73.77, 68.50, 67.79, 67.17, 47.69, 43.04, 40.76, 40.64, 40.62, 40.22, 39.01, 36.32, 36.25, 35.94, 34.27, 33.97, 33.72, 30.13, 29.53, 28.43, 24.48, 23.58, 23.40, 12.38; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 496.4108 (100%), calcd. 496.4114. Example 9 Syntheses of Compounds 109, and 126-129 Compound 126: Compound 125 (2.30 g, 3.52 mmol) was dissolved in MeOH (50 mL) and CH2Cl2 (100 mL). A small amount of Et3N was added, and the solution was cooled to −78° C. Ozone was bubbled through the solution until a blue color persisted. Me2S (4 mL) was introduced followed by the addition of NaBH4 (0.266 g, 0.703 mmol) in MeOH (10 mL). The resulting solution was allowed to warm and stir overnight. The solution was concentrated in vacuo, and brine (60 mL) was added. The mixture was extracted with EtOAc (40 ml, 2×30 mL), and the combined extracts were washed with brine and dried over anhydrous Na2SO4. Silica gel chromatography (EtOAc) afforded the product (1.24 g, 76% yield) as a white solid. m.p. 219-220° C.; 1H NMR (CDCl3, 300 MHz) δ 5.10 (t, J=2.8 Hz, 1 H), 4.90 (d, J=2.7 Hz, 1 H), 3.73-3.59 (m, 2 H), 3.56-3.44 (m, 1 H), 2.13 (s, 3 H), 2.09 (s, 3 H), 2.07-0.95 (series of multiplets, 23 H), 0.91 (s, 3 H), 0.83 (d, J=6.3 Hz, 3 H), 0.74 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 170.84, 170.82, 75.63, 71.77, 71.03, 60.73, 48.10, 45.26, 43.54, 41.16, 38.78, 37.89, 35.00, 34.43, 32.26, 31.50, 30.60, 29.07, 27.50, 25.70, 22.96, 22.71, 21.81, 21.63, 18.18, 12.35; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 465.3197 (20%), calcd. 465.3216. Compound 127: Compound 126 (1.24 g, 2.67 mmol) was dissolved in MeOH (30 mL), and NaOH (0.54 g, 13.4 mmol) was added. The suspension was refluxed under N2 for 24 hr. The MeOH was removed in vacuo followed by the addition of H2O (50 mL). The precipitate was filtered, washed with H2O and then dried in vacuo to give a white solid (1.02 g). This solid was dissolved in DMF (40 mL) followed by the sequential addition of NEt3 (1.12 mL, 8.02 mmol), DMAP (16.3 mg, 0.13 mmol) and trityl chloride (1.49 g, 5.34 mmol). The suspension was stirred under N2 for 12 hr and then heated up to 50° C. for 24 hr. H2O (100 mL) was added to the cooled suspension, and the mixture was extracted with EtOAc (3×50 mL). The combined extracts were washed with brine (100 mL), dried over anhydrous Na2SO4, and concentrated in vacuo. Silica gel chromatography (EtOAc) afforded the product (1.20 g, 72% yield) as a pale yellow glass. To this glass was added dry THF (80 mL) and NaH (60% in mineral oil, 0.77 g, 19.3 mmol). The suspension was refluxed under N2 for half an hour before the introduction of allylbromide (1.67 mL, 19.3 mmol). After 48 hr at reflux, another 10 eq. of NaH and allylbromide were introduced. After another 48 hr, the reaction mixture was cooled and H2O (100 mL) was slowly added. The resulting mixture was extracted with hexanes (3×50 mL), and the combined extracts were washed with brine (100 mL) and dried over anhydrous Na2SO4. Silica gel chromatography (5% EtOAc in hexanes) afforded the product (1.27 g, 64% yield for all three steps) as a clear glass. 1H NMR (CDCl3, 300 MHz) δ 7.46-7.43 (m, 6 H), 7.29-7.16 (m, 9 H), 5.98-5.81 (m, 3 H), 5.29-5.18 (m, 3 H), 5.14-5.03 (m, 3 H), 4.11-3.97 (m, 4 H), 3.75-3.67 (m, 2 H), 3.49 (bs, 1 H), 3.32-3.13 (d, J=2.4 Hz, 1 H), 3.20-3.13 (m, 2 H), 3.00 (m, 1 H), 2.33-2.12 (m, 3 H), 2.03-0.92 (series of multiplets, 19 H), 0.88 (s, 3 H), 0.78 (d, J=6.6 Hz, 3 H), 0.65 (s, 3 H); C NMR (CDCl3, 75 MHz) δ 144.71, 136.08, 136.04, 135.94, 128.80, 127.76, 126.86, 116.30, 115.57, 86.53, 80.77, 79.20, 74.96, 69.42, 69.34, 68.81, 62.00, 46.87, 46.48, 42.67, 42.11, 39.90, 36.15, 35.50, 35.14, 35.10, 33.23, 28.99, 28.09, 27.75, 27.56, 23.36, 23.32, 23.12, 18.24, 12.66; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 765.4875 (100%), calcd. 765.4859. Compound 128: To a THF (40 mL) solution of 127 (1.27 g, 1.71 mmol) was added 9-BBN (0.5 M solution in THF, 17.1 mL). The mixture was stirred for 12 hr before the addition of NaOH (20% solution, 10 mL) and H2O2 (30% solution, 10 mL). The resulted mixture was refluxed for 1 hr followed by the addition of brine (100 mL) and extraction with EtOAc (4×30 mL). The combined extracts were dried over anhydrous Na2SO4 and concentrated in vacuo. Silica gel chromatography (5% MeOH in CH2Cl2) afforded the product (1.26 g, 93% yield) as a clear glass. 1H NMR (5% CD3OD in CDCl3, 300 MHz) δ 7.46-7.43 (m, 6 H), 7.32-7.20 (m, 9 H), 3.94 (s, 3 H), 3.78-3.56 (m, 10 H), 3.48 (bs, 1 H), 3.32-3.26 (m, 2 H), 3.24-3.12 (m, 3 H), 3.00 (dd, J=8.2 and 6.1 Hz, 1 H), 2.23-1.96 (m, 3 H), 1.90-0.95 (series of multiplets, 25 H), 0.90 (s, 3 H), 0.77 (d, J=6.6 Hz, 3 H), 0.66 (s, 3 H); 13C NMR (5% CD3OD in CDCl3, 75 MHz) δ 144.52, 128.64, 127.64, 126.76, 86.43, 80.55, 79.31, 77.65, 77.23, 76.80, 76.06, 66.17, 66.01, 65.41, 61.93, 61.20, 60.73, 60.39, 47.29, 46.08, 42.65, 41.62, 39.49, 36.02, 35.10, 34.89, 34.77, 32.89, 32.71, 32.41, 32.26, 28.68, 27.70, 27.51, 27.19, 23.26, 22.66, 22.50, 18.23, 12.34; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 819.5169 (100%), calcd. 819.5099. Compound 129: To a CH2Cl2 (50 mL) solution of compound 128 (1.26 g, 1.58 mmol) at 0° C. was added Et3N (0.92 mL, 6.60 mmol) followed by mesyl chloride (0.47 mL, 6.05 mmol). After 15 minutes, H2O (10 mL) was followed by brine (80 mL). The mixture was extracted with EtOAc (60 mL, 2×30 mL) and the combined extracts were dried over anhydrous Na2SO4. After removal of solvent in vacuo, the residue was dissolved in DMSO (10 mL) and NaN3 (1.192 g, 18.3 mmol) was added. The suspension was heated to 60° C. under N2 overnight. H2O (100 mL) was added, and the mixture was extracted with EtOAc (3×40 mL). The combined extracts were washed with brine and dried over anhydrous Na2SO4. Removal of the solvent in vacuo afforded a pale yellow oil. The oil was dissolved in MeOH (10 mL) and CH2Cl2 (20 mL) and TsOH (17.4 mg, 0.092 mmol) was added. After 12 hr, saturated aqueous NaHCO3 (20 mL) and brine (50 mL) were added and the mixture was extracted with EtOAc (3×40 mL). The combined extracts were washed with brine (50 mL) and dried over anhydrous Na2SO4. Silica gel chromatography (EtOAc/hexanes 1:3) afforded the desired product (0.934, 94%) as a pale yellow oil. 1H NMR (CDCl3, 500 MHz) δ 3.75-3.70 (m, 1 H), 3.68-3.63 (m, 2 H), 3.62-3.57 (m, 1 H), 3.53 (t, J=6.1 Hz, 2 H), 3.50 (bs, 1 H), 3.46-3.38 (m, 6 H), 3.26 (d, J=2.4 Hz, 1 H), 3.24-3.20 (m, 1 H), 3.16-3.12 (m, 1 H), 3.10-3.04 (m, 1 H), 2.17-2.04 (m, 3 H), 1.96-1.63 (m, 14 H), 1.53-1.45 (m, 3 H), 1.35-1.20 (m, 7 H), 1.08-1.00 (m, 1H), 0.97-0.88 (m, 1 H), 0.94 (d, J=6.8 Hz, 3 H), 0.89 (s, 3 H), 0.67 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.64, 79.81, 76.06, 65.05, 64.49, 64.34, 61.03, 49.02, 48.98, 48.78, 46.93, 46.53, 42.76, 42.01, 39.83, 39.14, 35.46, 35.33, 35.12, 32.97, 29.79, 29.73, 29.10, 27.90, 27.68, 23.56, 23.06, 22.88, 18.24, 12.60; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 652.4285 (100%), calcd. 652.4295. Compound 109: Compound 129 (0.245 g, 0.391 mmol) was dissolved in THF (30 mL) followed by the addition of LiAlH4 (59 mg, 1.56 mmol). The gray suspension was stirred under N2 12 hr. Na2SO4. 10H2O powder (˜1 g) was carefully added. After the gray color in the suspension dissipated, anhydrous Na2SO4 was added and the precipitate was removed by filtration. After the removal of solvent, the residue was purified by silica gel chromatography (CH2Cl2/MeOH/28% NH3.H2O 10:5:1 then 10:5:1.5). The solvent was removed from relevant fractions, and 1 M HCl (4 mL) was added to dissolve the residue. The resulting clear solution was extracted with Et2O (3×10 mL). 20% NaOH solution was added until the solution became strongly basic. CH2Cl2 (4×10 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4, and removal of solvent in vacuo gave the desired product (0.15 g, 71% yield) as a colorless oil. 1H NMR (˜20% CD3OD in CDCl3, 500 MHz) δ 4.73 (bs, 7 H), 3.74-3.70 (m, 1 H), 3.65-3.60 (m, 2 H), 3.56-3.52 (m, 4 H), 3.31-3.28 (m, 2 H), 3.16-3.09 (m, 2H), 2.82-2.71 (m, 6 H), 2.19-2.06 (m, 3 H), 1.97-1.66 (series of multiplets, 15 H), 1.58-1.48 (m, 3 H), 1.38-0.98 (m, 7 H), 0.96 (d, J=6.8 Hz, 3 H), 0.93 (s, 3 H), 0.71 (s, 3 H); 13C NMR (˜20% CD3OD in CDCl3, 75 MHz) δ 81.80, 80.60, 77.17, 67.88, 67.86, 67.18, 60.73, 48.11, 47.28, 43.93, 42.99, 41.34, 40.76, 40.72, 40.24, 39.70, 36.33, 36.18, 35.86, 34.29, 33.99, 33.96, 33.83, 29.60, 29.00, 28.57, 28.54, 24.33, 23.59, 23.48, 18.86, 13.04; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 552.4756 (100%), calcd. 552.4772. Example 10 Syntheses of Compounds 108 and 130 Compound 130: o-NO2C6H4SeCN (0.094 g, 0.21 mmol) and Bu3P (0.095 mL, 0.38 mmol) were stirred in dry THF (5 mL) at 0° C. for ½ hr followed by the addition of compound 129 (0.10 g, 0.159 mmol) in THF (2 mL). The suspension was stirred for 1 hr followed by the addition of H2O2 (30% aqueous solution, 2 mL). The mixture was stirred for 12 hr followed by extraction with hexanes (4×10 mL). The combined extracts were dried over anhydrous Na2SO4. The desired product (0.035 g, 36% yield) was obtained as pale yellowish oil after silical gel chromatography (10% EtOAc/hexanes). 1H NMR (CDCl3, 500 MHz) δ 5.73-5.66 (ddd, J=17.1, 10.2, 8.3 Hz, 1 H), 4.90 (dd, J=17.1, 2.0 Hz, 1 H), 4.82 (dd, J=10.2 Hz, 1.96 Hz, 1 H), 3.68-3.64 (m, 1 H), 3.62-3.58 (m, 1 H), 3.54-3.26 (m, 9 H), 3.25-3.22 (m, 2 H), 3.15-3.11 (m, 1 H), 3.10-3.04 (m, 1 H), 2.17-1.62 (series of multiplets, 18 H), 1.51-1.43 (m, 2 H), 1.35-1.18 (m, 4 H), 1.06-0.91 (m, 2 H), 1.02 (d, J=6.3 Hz, 3 H), 0.90 (s, 3 H), 0.68 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 145.50, 111.72, 80.60, 79.82, 76.09, 65.06, 64.50, 64.45, 49.05, 48.97, 48.79, 46.43, 46.13, 42.76, 42.03, 41.30, 39.84, 35.49, 35.34, 35.15, 29.82, 29.80, 29.75, 29.11, 28.00, 27.84, 27.68, 23.56, 23.08, 22.95, 19.79, 12.87; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 634.4167 (90.6%), calcd. 634.4169. Compound 108: Compound 130 (0.105 g, 0.172 mmol) was dissolved in CH2Cl2 (5 mL) and MeOH (5 mL) at −78° C. 03 was bubbled into the solution for ca. 20 min. Me2S (1 mL) was added followed, and the solvent was removed in vacuo. The residue was dissolved in THF (15 mL), and LiAlH4 (0.033 g, 0.86 mmol) was-added. The suspension was stirred for 12 hr. Na2SO4. 10H2O (˜2 g) was carefully added. After the gray color of the suspension dissipated, anhydrous Na2SO4 was added and the precipitate was removed by filtration. Concentration and silica gel chromatography (CH2Cl2/MeOH/28% NH3.H2O 10:5:1.5 then 9:6:1.8) yielded a white glass. To this material was added 1 M HCl (4 mL). The resulting clear solution was washed with Et2O (3×10 mL). 20% NaOH solution was added to the aqueous phase until the solution became strongly basic. CH2Cl2 (4×10 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4 and removal of solvent gave the desired product (0.063 g, 68% yield) as a colorless oil. 1H NMR (˜10% CD3OD in CDCl3, 500 MHz) δ 4.76 (bs, 7 H), 3.75-3.71 (m, 1 H), 3.66-3.62 (m, 1 H), 3.58-3.52 (in, 4 H), 3.33-3.29 (m, 2 H), 3.22 (dd, J=10.5 and 7.6 Hz, 1 H), 3.15-3.09 (m, 2 H), 2.81 (t, J=6.8 Hz, 2 H), 2.76-2.71 (m, 4 H), 2.19-2.08 (m, 3 H), 2.00-1.66 (series of multiplets, 14 H), 1.58-1.45 (m, 3 H), 1.40-1.08 (m, 5 H), 1.03 (d, J=6.8 Hz, 3 H), 1.02-0.96 (m, 1 H), 0.93 (s, 3 H), 0.72 (s, 3 H); 13C NMR (˜10% CD3OD in CDCl3, 75 MHz) δ 81.74, 80.64, 77.23, 67.95, 67.87, 67.18, 47.32, 44.59, 43.72, 43.01, 41.26, 40.80, 40.71, 40.23, 40.02, 36.36, 36.20, 35.87, 34.27, 33.99, 33.90, 29.60, 29.05, 28.58, 28.08, 24.49, 23.62, 23.46, 16.84, 13.12; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 538.4578 (4.7%), calcd. 538.4584. Example 11 Syntheses of Compounds 132-135 Compound 132: Compound 115 (0.118 g, 0.183 mmol) was dissolved in dry CH2Cl2 (10 mL), and SO3 pyridine complex (0.035 g, 0.22 mmol) was added. The suspension was stirred for 12 hr. The solvent was removed in vacuo to give white powder. To the white powder was added 1 M HCl (10 mL) and the resulting mixture was extracted with CH2Cl2 (4×10 mL). The combined extracts were dried over anhydrous Na2SO4. The desired product (0.11 g, 84%) was obtained as a pale yellow oil after silica gel chromatography (10% MeOH in CH2Cl2). 1H NMR (˜10% CD3OD in CDCl3, 500 MHz) δ 4.03 (t, J=6.8 Hz, 2 H), 3.69-3.65 (m, 1 H), 3.62-3.58 (m, 1 H), 3.55 (t, J=6.1 Hz, 2 H), 3.51 (bs, 1 H), 3.46-3.38 (m, 6 H), 3.27 (d, J=2.4 Hz, 1 H), 3.26-3.21 (m, 1H), 3.18-3.07 (m, 2 H), 2.18-2.03 (m, 3 H), 1.95-1.47 (series of multiplets, 19 H), 1.40-0.96 (series of multiplets, 9 H), 0.92 (d, J=6.8 Hz, 3 H), 0.91 (s, 3 H), 0.66 (s, 3, H); 13C NMR (˜10% CD3OD in CDCl3, 75 MHz) δ 80.43, 79.68, 75.87, 69.30, 64.82, 64.32, 64.14, 48.78, 48.73, 48.50, 46.44, 46.21, 42.49, 41.76, 39.61, 35.36, 35.17, 35.06, 34.85, 31.73, 29.53, 29.46, 29.44, 28.84, 27.68, 27.48, 27.38, 25.91, 23.30, 22.75, 22.66, 17.70, 12.32; HRFAB-MS (thioglycerol+Na30 matrix) m/e: ([M−H+2Na]+) 768.3831 (100%), calcd. 768.3843. The azides were reduced by treating the triazide (0.11 g, 0.15 mmol) with Ph3P (0.20 g, 0.77 mmol) in THF (10 mL) and H2O (1 mL). The mixture was stirred for 3 days. The solvent was removed in vacuo, and the residue was purified by silica gel chromatography (CH2Cl2/MeOH/28% NH3.H2O 12:6:1 then 10:5:1.5) to afford the desired product (0.077 g, 78% yield) as a glass. HCl in Et2O (1 M, 0.5 mL) was added to the glass to give the corresponding HCl salt. 1H NMR (˜10% CDCl3 in CD3OD, 500 MHz) δ 4.81 (s, 10 H), 4.07-3.97 (m, 2 H), 3.82 (bs, 1 H), 3.11 (bs, 1 H), 3.65 (t, J=5.2 Hz, 2 H), 3.57 (bs, 1 H), 3.37-3.30 (m, 2 H), 3.22-3.02 (m, 8 H), 2.12-1.71 (series of multiplets, 17 H), 1.65-1.01 (series of multiplets, 13 H), 0.97 (d, J=6.8 Hz, 3 H), 0.94 (s, 3 H), 0.73 (s, 3 H); 13C NMR (˜10% CDCl3 in CD3OD, 75 MHz) δ 81.89, 80.58, 77.50, 70.04, 66.71, 66.56, 66.02, 47.11, 46.76, 44.20, 42.66, 40.50, 39.60, 39.40, 36.24, 36.11, 35.89, 35.67, 32.28, 29.38, 29.23, 29.10, 28.94, 28.49, 26.06, 24.21, 23.46, 23.30, 18.50, 12.86; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 668.4271 (100%), calcd. 668.4258. Compound 133: The mesylate derived from 23 (0.19 g, 0.264 mmol) was stirred with excess octyl amine (2 mL) at 80° C. for 12 hr. After removal of octylamine in vacuo, the residue was chromatographed (silica gel, EtOAc/hexanes 1:4 with 2% Et3N) to afford the desired product (0.19 g, 95% yield) as a pale yellow oil. 1H NMR (CDCl3, 300 MHz) δ—3.69-3.37 (series of multiplets, 11 H), 3.26-3.00 (m, 4 H), 2.61-2.53 (m, 4H), 2.20-2.02 (m, 3 H), 1.98-0.99 (series of multiplets, 40 H), 0.92-0.85 (m, 9 H), 0.65 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 80.60, 79.74, 76.05, 64.97, 64.40, 64.28, 50.79, 50.25, 49.00, 48.90, 48.71, 46.47, 46.34, 42.65, 41.96, 39.80, 35.77, 35.41, 35.27, 35.05, 33.73, 31.96, 30.25, 29.76, 29.74, 29.67, 29.39, 29.05, 27.84, 27.61, 27.55, 26.70, 23.50, 23.00, 22.82, 22.79, 18.06, 14.23, 12.54; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 755.6012 (100%), calcd. 755.6024. The triazide (0.18 g, 0.239 mmol) was dissolved in THF (10 mL) and EtOH (10 mL). Lindlar catalyst (44 mg) was added, and the suspension was shaken under H2 (50 psi) for 12 hr. After removal of the solvent in vacuo, the residue was purified by silica gel chromatography (CH2Cl2/MeOH/28% NH3.H2O 10:5:1, then 10:5:1.5). To the product, 1 M HCl (2 mL) and the resulting clear solution was extracted with Et2O (2×10 mL). 20% NaOH solution was added until the solution became strongly basic. CH2Cl2 (20 mL, 2×10 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4, and removal of solvent in vacuo gave the desired product (0.114 g, 68% yield) as a clear oil. 1H NMR (˜20% CDCl3 in CD3OD, 500 MHz) δ 4.79 (bs, 7 H), 3.74-3.70 (m, 1 H), 3.66-3.61 (m, 1 H), 3.56-3.51 (m, 3 H), 3.31-3.29 (m, 2 H), 3.16-3.09 (m, 2 H), 2.88-2.72 (m, 6 H), 2.59-2.51 (m, 4 H), 2.18-2.07 (m, 3 H), 1.97-1.66 (series of multiplets, 14 H), 1.62-0.97 (series of multiplets, 25 H), 0.95 (d, J=6.3 Hz, 3 H), 0.93 (s, 3 H), 0.89 (t, J=6.8 Hz, 3H), 0.70 (s, 3 H); 13C NMR (˜20% CDCl3 in CD3OD, 75 MHz) δ 81.82, 80.63, 77.23, 67.85, 67.19, 51.20, 50.69, 47.82, 47.24, 43.92, 43.01, 41.30, 40.80, 40.68, 40.22, 36.74, 36.38, 36.20, 35.87, 34.66, 34.15, 33.87, 32.90, 30.54, 30.39, 30.30, 29.64, 29.03, 28.59, 28.41, 26.96, 24.37, 23.65, 23.48, 18.75, 14.63, 13.09; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 677.6309 (46.6%), calcd. 677.6309. Compound 134: Compound 133 (0.08 g, 0.12 mmol) was dissolved in CHCl3 (5 mL) and MeOH (5 mL), aminoiminosulfonic acid (0.045 g, 0.36 mmol) was added, and the suspension was stirred for 12 hr. The solvent was removed in vacuo, and the residue was dissolved in 1 M HCl (6 mL) and H2O (10 mL). The solution was washed with Et2O (3×5 mL), and 20% NaOH solution was then added dropwise until the solution became strongly basic. The basic mixture was extracted with CH2Cl2 (4×5 mL). The combined extracts were dried over anhydrous Na2SO4 and concentrated in vacuo to give the desired product (0.087 g, 91% yield) as a white glass. 1H NMR (˜20% CDCl3 in CD3OD, 500 MHz) δ 4.96 (bs, 13 H), 3.74-3.68 (m, 1 H), 3.65-3.50 (m, 4 H), 3.38-3.18 (series of multiplets, 10 H), 2.60-2.50 (m, 4 H), 2.15-1.99 (m, 3 H), 1.88-1.72 (m, 14 H), 1.60-0.99 (series of multiplets, 25 H), 0.94 (bs, 6 H), 0.89 (t, J=6.6 Hz, 3 H), 0.71 (s, 3 H); 13C NMR (˜20% CDCl3 in CD3OD, 75 MHz) δ 159.00, 158.87, 158.72, 81.68, 79.93, 76.95, 66.59, 65.93, 65.45, 50.82, 50.40, 47.64, 46.94, 43.67, 42.27, 40.18, 39.25, 36.19, 35.66, 35.40, 34.21, 32.45, 30.51, 30.26, 30.18, 30.10, 29.86, 29.35, 28.71, 28.15, 28.00, 26.87, 23.94, 23.44, 23.23, 23.12, 18.61, 14.42, 12.98; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 803.6958 (18.4%), calcd. 803.6953. Compound 135: The mesylate derived from 23 (0.092 g, 0.128 mmol) was dissolved in DMSO (2 mL) followed by the addition of NaN3 (0.0167 g, 0.256 mmol). The suspension was heated to 70° C. for 12 hr. H2O (20 mL) was added to the cooled suspension, and the mixture was extracted with EtOAc/hexanes (1:1) (20 mL, 3×10 mL). The combined extracts were washed with brine (30 mL), dried over anhydrous Na2SO4, and concentrated in vacuo to give the product (0.081 g, 95% yield) as a pale yellow oil. 1H NMR (CDCl3, 300 MHz) δ 3.69-3.36 (m, 11 H), 3.25-3.02 (m, 6 H), 2.20-2.02 (m, 3 H), 1.97-1.60 (m, 15 H), 1.55-0.98 (m, 13 H), 0.92 (d, J=6.3 Hz, 3 H), 0.89 (s, 3 H), 0.66 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ—80.59, 79.77, 76.03, 65.01, 64.46, 64.30, 52.12, 48.99, 48.95, 48.76, 46.44, 46.42, 42.70, 41.99, 39.82, 35.56, 35.44, 35.31, 35.09, 33.09, 29.79, 29.77, 29.71, 29.08, 27.88, 27.78, 27.66, 25.65, 23.53, 23.03, 22.85, 18.00, 12.58; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 691.4512 (100%), calcd. 691.4496. The tetraazide (0.081 g, 0.12 mmol) was dissolved in THF (5 mL) and EtOH (10 mL). Lindlar catalyst (30 mg) was added, and the suspension was shaken under H2 (50 psi) for 12 hr. After removal of the solvent in vacuo, the residue was purified by silica gel chromatography (CH2Cl2/MeOH/28% NH3.H2O 5:3:1, then 2:2:1). To the product, 1 M HCl (2 mL) was added, and the resulting solution was washed with Et2O (2×10 mL). 20% NaOH solution was added to the aqueous phase until the solution became strongly basic. CH2Cl2 (10 mL, 2×5 mL) was used to extract the basic solution. The combined extracts were dried over anhydrous Na2SO4, and concentration in vacuo gave the desired product (0.044 g, 64% yield) as a colorless oil. 1H NMR (˜20% CDCl3 in CD3OD, 500 MHz) δ 4.79 (bs, 8 H), 3.74-3.70 (m, 1 H), 3.66-3.62 (m, 1 H), 3.56-3.52 (m, 3 H), 3.31-3.27 (m, 2 H), 3.16-3.10 (m, 2 H), 2.82-2.70 (m, 6 H), 2.64-2.54 (m, 2 H), 2.19-2.07 (m, 3 H), 1.99-1.66 (series of multiplets, 14 H), 1.58-0.96 (series of multiplets, 13 H), 0.96 (d, J=6.6 Hz, 3 H), 0.93 (s, 3 H), 0.70 (s, 3 H); 13C NMR (˜20% CDCl3 in CD3OD, 75 MHz) δ 81.96, 90.76, 77.33, 67.92, 67.26, 47.84, 47.33, 44.04, 43.24, 43.15, 41.40, 40.91, 40.78, 40.29, 36.82, 36.48, 36.28, 35.96, 34.39, 34.11, 30.59, 29.69, 29.13, 28.68, 28.64, 24.43, 23.69, 23.48, 18.77, 13.06; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+H]+) 565.5041 (100%), calcd. 565.5057. Example 12 Syntheses of Compounds 203a-b, 207a-c, 208a-c, 209a-c, and 210a-b Compounds 203a-b, 207a-c, 208a-c, 209a-c, and 210a-b: BOC-glycine was reacted with DCC, DMAP and cholic acid derivative 201 (Scheme 11) to give triester 202a in good yield. A similar reaction incorporating BOC-β-alanine was also successful, giving 202b. Deprotection of 202a and 202b with HCl in dioxane, followed by purification (SiO2 chromatography with a CH2Cl2MeOH/NH4OH eluent), gave triesters 203a and 203b in good yield. Triamides of glycine and β-alanine (207a and 207b, respectively) were formed using the same reaction conditions (Scheme 12). Triamides with α-branched amino acids could also be formed. For example, under the conditions described, a triamide with bis-BOC-lysine side chains was formed (compound 207c). The C24 esters of 207a-c were hydrolyzed with LiOH in THF and methanol to give alcohols 208a-c. Deprotection using HCl in dioxane (208a-c) gave triamides 209a-c in good yield. In addition, alcohols 208a and 208b were mesylated and reacted with benzylmethyl amine. Deprotection of the resulting compounds with HCl in dioxane gave triamides 210a and 210b (Scheme 12). The antibacterial properties of these compounds are summarized in Table 14. Example 13 Synthesis of Compounds 302, 312-321, 324-326, 328-331 and 341-343 Compound 302: Compound 308 (5β-cholanic acid 3,7,12-trione methyl ester) was prepared from methyl cholate and pyridinium dichromate in near quantitative yield from methyl cholate. Compound 308 can also be prepared as described in Pearson et al., J. Chem. Soc. Perkins Trans. l 1985, 267; Mitra et al., J. Org. Chem. 1968, 33, 175; and Takeda et al., J. Biochem. (Tokyo) 1959, 46, 1313. Compound 308 was treated with hydroxylamine hydrochloride and sodium acetate in refluxing ethanol for 12 hr (as described in Hsieh et al., Bioorg. Med. Chem. 1995, 3, 823), giving 309 in 97% yield. A 250 ml three neck flask was charged with glyme (100 ml); to this was added 309 (1.00 g, 2.16 mmol) and sodium borohydride (2.11 g, 55.7 mmol). TiCl4 (4.0 mL, 36.4 mmol) was added to the mixture slowly under nitrogen at 0° C. The resulting green mixture was stirred at room temperature for 24 hours and then refluxed for another 12 h. The flask was cooled in an ice bath, and ammonium hydroxide (100 mL) was added. The resulting mixture was stirred for 6 hours at room temperature. Conc. HCl (60 mL) was added slowly, and the acidic mixture was stirred for 8 hours. The resulting suspension was made alkaline by adding solid KOH. The suspension was filtered and the solids were washed with MeOH. The combined filtrate and washings were combined and concentrated in vacuo. The resulting solid was suspended in 6% aqueous KOH (100 mL) and extracted with CH2Cl2 (4×75 mL). The combined extracts were dried over Na2SO4, and solvent was removed in vacuo to give 1.14 g of a white solid. The mixture was chromatographed on silica gel (CH2Cl2/MeOH/NH4OH 12:6:1) giving 302 (0.282 g, 33% yield), 3 (0.066 g, 8% yield), 4 (0.118 g, 14% yield). Compound 302: m.p. 200-2020 C; 1H NMR (˜10% CDCl3 in CD3OD, 300 MHz) δ 4.81 (bs, 7 H), 3.57-3.49 (m, 2 H), 3.14 (t, J=3.2 Hz, 1 H), 2.97 (bs, 1 H), 2.55-2.50 (m, 1 H), 2.15-2.10 (m, 1 H), 1.95-1.83 (m, 3 H), 1.74-0.99 (series of multiplets, 20 H), 1.01 (d, J=6.4 Hz, 3 H), 0.95 (s, 3 H), 0.79 (s, 3 H); 13C NMR (˜10% CDCl3 in CD3OD, 75 MHz) 63.28, 55.01, 52.39, 49.20, 48.69, 47.00, 43.24, 42.77, 41.03, 40.27, 36.82, 36.35, 35.75, 35.12, 32.77, 31.36, 30.10, 28.54, 27.88, 26, 96, 24.35, 23.38, 18.18, 14.23, HRFAB-MS (thioglycerol+Na+ matrix) m/e; ([M+H]+) 392.3627 (100%); calcd. 392.3641. Octanyl cholate (328): Cholic acid (3.14 g, 7.43 mmol) and 10-camphorsulfonic acid (0.52 g, 2.23 mmol) were dissolved in octanol (3.5 mL, 23.44 mmol). The solution was warmed to 40-50° C. in oil bath under vacuum (˜13 mm/Hg). After 14 h, the remaining octanol was evaporated under high vacuum. The crude product was purified via chromatography (silica gel, 5% MeOH in CH2Cl2) to afford the desired product (2.81 g, 73% yield) as a white powder. 1H NMR (CDCl3, 500 MHz) δ 4.06 (t, J=6.7 Hz, 2 H), 3.98 (s, 1 H), 3.86 (s, 1 H), 3.48-3.44 (m, 1 H), 2.41-2.34 (m, 1 H), 2.28-2.18 (m, 3 H), 1.98-1.28 (series of multiplets, 35 H), 0.99 (d, J=3.3 Hz, 3 H), 0.90 (s, 3 H), 0.89 (t, J=7 Hz, 3 H), 0.69 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 154.38, 73.18, 72.14, 68.63, 56.07, 50.02, 49.32, 47.07, 46.74, 41.96, 41.67, 39.84, 39.76, 35.66, 35.45, 34.95, 34.86, 34.15, 32.97, 32.91, 31.65, 31.11, 30.68, 28.39, 27.78, 26.66, 26.52, 25.82, 25.70, 25.54, 25.15, 24.95, 23.45, 22.69, 17.77, 12.71; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 543.4015 (100%), calcd. 543.4026. Representative synthesis of compounds 329-331: Octanyl cholate (328) (0.266 g, 0.511 mmol), N-t-Boc-glycine (0.403 g, 2.298 mmol), DCC (0.474 g, 2.298 mmol) and DMAP (0.0624 g, 0.051 mmol) were mixed in CH2Cl2 (15 mL) for 3 h. The resulting white precipitate was removed by filtration. The filtrate was concentrated, and the product was purified by chromatography (silica gel, EtOAc/Hexane 1:2) to afford the desired product (0.481 g, 95% yield) as a white powder. Compound 329 1H NMR (CDCl3, 300 MHz) δ 5.18 (br, 3 H), 5.01 (s, 1 H), 4.61 (m, 1 H), 4.04 (t, J=6.5 Hz, 2 H), 3.97-3.88 (series of multiplets, 6 H), 2.39-2.15 (series of multiplets, 2 H), 2.06-1.02 (series of multiplets, 35 H), 1.46 (s, 18 H), 1.45 (s, 9 H), 0.93 (s, 3 H), 0.88 (t, J=6.7 Hz, 3 H), 0.81 (d, J=6 Hz, 3 H), 0.74 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 174.26, 170.19, 169.9, 169.78, 155.87, 155.67, 79.95, 76.47, 75.167, 72.11, 64.55, 47.40, 45.28, 43.17, 42.86, 40.82, 37.94, 34.71, 34.63, 34.43, 31.86, 31.340, 31.20, 30.76, 29.29, 29.25, 28.80, 28.72, 28.42, 28.06, 27.96, 27.19, 26.81, 26.29, 26.012, 25.66, 22.87, 22.71, 22.57, 17.55, 14.18, 12.27; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+)-1014.6261 (100%), calcd. 1014.6242. Compound 330: 1H NMR (CDCl3, 500 MHz) δ 5.10 (s, 1 H), 4.92 (d, J=2.44 Hz, 1 H), 4.55 (m, 1 H), 4.00 (t, J=6.8 Hz, 2 H), 3.39-3.33 (series of multiplets, 6 H), 2.595-2.467 (series of multiplets, 6 H), 2.31-2.12 (series of multiplets, 2 H), 2.01-1.00 (series of multiplets, 37 H), 1.39 (s, 27 H), 0.88 (s, 3 H), 0.84 (t, J=6.8 Hz, 3 H), 0.76 (d, J=6.3 Hz, 3 H), 0.69 (s, 3 H); 13C NMR (CDCl3, 75 MHz) δ 174.16, 172.10, 171.78, 171.67, 155.95, 79.45, 75.67, 74.21, 71.10, 64.63, 47.79, 45.27, 43.52, 40.97, 37.92, 36.35, 35.14, 35.05, 34.90, 34.71, 34.46, 31.91, 31.45, 30.95, 29.35, 29.31, 28.96, 28.78, 28.56, 28.55, 27.22, 26.98, 26.269, 25.71, 23.00, 22.77, 22.64, 17.75, 14.24, 12.39; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 1056.6702 (100%), calcd. 1056.6712. Compound 331 13C NMR (CDCl3, 125 MHz) δ 174.00, 172.75, 172.41, 172.30, 156.03, 79.00, 75.28, 73.79, 70.77, 64.39, 47.43, 45.04, 43.21, 40.76, 40.00, 39.93, 37.78, 34.74, 34.62, 34.23, 32.19, 32.01, 31.70, 31.24, 30.77, 29.13, 29.10, 28.67, 38.58, 28.38, 25.86, 25.37, 22.56, 22.38, 17.51, 14.05, 12.13; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 1098.7181 (100%), calcd. 1098.7181. Representative synthesis of compounds 341-343: To compound 329 (0.463 g, 0.467 mmol) was added HCl in dioxane (0.3 mL, 4.0 M). After stirring the mixture for 30 min, the excess HCl and solvent were removed in vacuo. The product was isolated, after chromatography (silica gel, CH2Cl2/MeOH/NH3.H2O 10:1.2:0.1) as a (0.271 g, 84%) pale oil. The trihydrochloride salt of 341 was prepared by addition of HCl in dioxane and evaporation of excess HCl and dioxane in vacuo giving a white powder. Compound 341: 1H NMR (CDCl3 with ˜10% CD3OD, 500 MHz) δ 5.16 (s, 1 H), 4.99 (t, J=3.6 Hz, 1 H), 4.61 (m, 1 H), 4.04 (t, J=6.8 Hz, 2 H), 3.51-3.36 (m, 6 H), 2.34-2.15 (m, 2 H), 2.00-1.05 (series of multiplets, 40 H), 0.93 (s, 3 H), 0.88 (t, J=7.1 Hz, 3H), 0.80 (d, J=3.2 Hz, 3 H), 0.74 (s, 3 H); 13C NMR (CDCl3 and ˜10% CD3OD, 75 MHz) δ 174.32, 173.92, 173.81, 76.08, 74.67, 71.61, 64.73, 47.64, 45.39, 44.41, 43.49, 40.97, 37.99, 34.99, 34.77, 34.71, 34.52, 31.96, 31.54, 31.35, 30.96, 29.39, 29.36, 29.02, 28.82, 27.32, 27.11, 26.11, 25.83, 23.01, 22.82, 22.69, 17.79, 14.28, 12.41; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 714.4651 (100%), calcd. 714.4669. Compound 342: 1H NMR (CDCl3 and ˜10% CD3OD, 300 MHz) δ 5.142 (s, 1 H), 4.96 (d, J=2.7 Hz, 1 H), 4.60, (m, 1 H), 4.04 (t, J=6.6 Hz, 2 H), 3.07-2.95 (series of multiplets, 6 H), 2.56-2.43 (series of multiplets, 6 H), 2.38-2.13 (series of multiplets, 2 H), 2.07-1.02 (series of multiplets, 36 H), 0.92 (s, 3 H), 0.88 (t, J-=6.6 Hz, 3 H), 0.82 (d, J=6.6 Hz, 3 H), 0.73 (s, 3 H); 13C NMR (CDCl3 and CD3OD, 75 MHz) δ 174.29, 172.29, 171.98, 171.92, 75.52, 74.09, 70.98, 64.67, 47.78, 45.26, 43.52, 40.98, 38.73, 38.62, 38.35, 38.07, 38.03, 37.99, 35.01, 34.81, 34.77, 34.49, 31.92, 31.50, 31.40, 30.99, 29.36, 29.33, 28.93, 28.80, 27.43, 26.96, 26.08, 25.56, 23.07, 22.79, 22.62, 17.73, 14.25, 12.34; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 714.4651 (100%), calcd. 714.4669. Compound 343: 1H NMR (CDCl3 and CD3OD, 500 MHz) δ 5.12 (s, 1 H) 4.93 (s, 1 H), 4.59 (m, 1 H), 4.04 (t, J=7 Hz, 2 H), 2.79-2.69 (series of multiplets, 6 H), 2.4621-2.2999 (series of multiplets, 6 H), 2.2033-1.0854-(series of multiplets, 42 H), 0.94 (s, 2 H), 0.91 (s, 1 H), 0.88 (t, J=7 Hz, 3 H), 0.82 (d, J=6.4 Hz, 3 H), 0.75 (s, 3 H); 13C NMR (CDCl3 and CD3OD, 75 MHz) δ 174.70, 171.97, 171.86, 171.75, 76.10, 74.55, 71.56, 64.85, 47.96, 45.31, 43.37, 40.87, 38.09, 34.86, 34.80, 34.73, 34.46, 32.84, 32.62, 32.27, 31.87, 31.75, 31.42, 31.08, 29.31, 29.28, 29.26, 28.78, 28.73, 27.38, 26.91, 26.05, 25.37, 23.24, 23.15, 22.95, 22.74, 22.71, 22.43, 17.78, 14.11, 12.28; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 798.5624 (100%), calcd. 798.5609. Benzyl cholate (312): Cholic acid (4.33 g, 10.62 mmol) and 10-caphorsulfonic acid (0.493 g, 2.21 mmol) were dissolved in benzyl alcohol (1.97 mL, 19.3 mmol). The suspension was heated to 50° C. in oil bath and stirred under vacuum (Q13 mm/Hg) for 16 h. Excess benzyl alcohol was removed in vacuo, and the crude product was chromatographed (silica gel, 5% MeOH in CH2Cl2) to give the desired product as a white powder (4.23 g, 81% yield). 1H NMR (CDCl3, 500 MHz) 67.34-7.33 (m, 5 H), 5.10 (d, J=1.5 Hz, 2 H), 3.92 (s, 1 H), 3.81 (s, 1 H), 3.42 (s, 1 H), 3.40 (br, m, 3 H), 2.44-2.38 (m, 1 H), 2.31-2.25 (m, 1 H), 2.219 (t, J=12 Hz, 2 H), 0.96 (d, J=5.5 Hz, 3 H), 0.86 (s, 3 H), 0.63 (s, 3 H); 13C NMR (CDCl3, 125 MHz) δ 174.25, 136.30, 128.66, 128.63, 128.32, 128.28, 128.24, 73.18, 71.98, 68.54, 66.18, 47.14, 46.56, 41.69, 39.65, 35.51, 35.37, 34.91, 34.84, 31.49, 31.08, 30.50, 28.31, 27.62, 26.47, 23.35, 22.65, 22.60, 17.42, 12.63, 12.57; HRFAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 521.3235 (100%), calcd. 521.3242. Representative synthesis of compounds 313-315: Benzyl cholate (312) (0.248 g, 0.499 mmol), N-t-Boc-glycine (0.404 g, 2.30 mmol), DCC (0.338 g, 1.49 mmol) and DMAP (0.051 g, 0.399 mmol) were added to CH2Cl2 (15 mL), and the suspension was stirred for 16 h. The resulting white precipitate was removed by filtration, and the filtrate was concentrated. The product was obtained after chromatorgraphy (silica gel, EtOAc/Hexane 0.6:1) as a white powder (0.329 g, 68%). Compound 313: 1H NMR (CDCl3, 300 MHz) δ 7.34-7.33 (m, 5 H), 5.16 (s, 1 H), 5.08 (dd, J=22.5 Hz, 12.3 Hz, 4 H), 5.00 (s, 1 H), 4.60 (m, 1 H), 4.04-3.81 (series of multiplets, 6 H), 2.43-1.01 (series of multiplets, 25 H), 1.46 (s, 9 H), 1.44 (s, 18 H), 0.92 (s, 3 H), 0.797 (d, J=5.7. Hz, 3 H), 0.69 (s, 1 H); 13C NMR (CDCl3, 75 MHz) δ 173.99, 170.25, 170.05, 169.85, 155.73, 136.19, 128.69, 128.45, 128.35, 80.06, 77.65, 77.23, 76.80, 76.53, 75.24, 72.19, 66.29, 47.46, 45.35, 43.24, 42.91, 40.89, 38.00, 34.79, 34.66, 34.49, 31.43, 31.25, 30.77, 28.88, 28.40, 27.23, 26.89, 25.74, 22.94, 22.65, 17.61, 12.32; FAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 992.5468 (100%), calcd. 992.5460. Representative synthesis of compounds 316-318: Compound 313 (0.505 g, 0.520 mmol) and Pd (5 wt. % on active carbon, 0.111 g, 0.0521 mmol) were added to MeOH (5 mL). The suspension was stirred under H2 (50 psi) for 20 hours. The solids were removed by filtration and the filtrate was concentrated. Purification of the product via chromatography (silica gel, 5% MeOH in CH2Cl2) gave a white powder (0.450 g, 98% yield). Compound 316: 1H NMR (CDCl3, 500 MHz) δ 5.20 (s, 1 H), 5.12 (br., 2H), 4.92 (s, 1 H), 4.55 (m, 1 H), 3.98-3.83 (series of multiplets, 6 H), 2.30-2.13 (series of multiplets, 2 H), 1.96-0.98 (series of multiplets, 30 H), 1.40 (s, 9 H), 1.39 (s, 18 H), 0.87 (s, 3 H), 0.76 (d, J=6.3 Hz, 3 H), 0.68 (s, 3 H); 13C NMR (CDCl3 75 MHz) δ 174.11, 165.60, 165.41, 165.22, 151.28, 151.14, 75.48, 75.26, 71.81, 70.57, 67.50, 45.95, 42.58, 40.65, 38.52, 38.16, 36.17, 33.28, 30.01, 29.78, 26.71, 26.42, 25.95, 24.16, 23.78, 23.40, 23.31, 22.55, 22.16, 21.03, 18.23, 17.93, 12.91, 7.61; FAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 902.4997 (21%), calcd. 902.4990. Representative synthesis of compounds 319-321: Compound 316 (0.375 g, 0.427 mmol), DCC (0.105 g, 0.512 mmol) and DMAP (0.062 g, 0.512 mmol) and N,N-dimethylethanolamine (0.09 ml, 0.896 mmol) were added to CH2Cl2 (15 mL). The mixture for 16 h, and solvent and excess N,N-dimethylethanolamine were removed in vacuo. The product was purified via chromatography (silica gel EtOAc/hexane/Et3N, 12:10:0.6) giving a white powder (0.330 g, 82% yield). 1H NMR (CDCl3 and ˜10% CD3OD, 500 MHz) δ 5.18 (s, 1 H), 5.00 (s, 1 H), 4.19 (t, J=5.0 Hz, 2 H), 3.92 (s, 3 H), 3.81 (s, 3 H), 2.62 (t, J=10 Hz, 2 H), 2.30 (s, 6 H), 1.47 (s, 9H), 1.47 (s, 1 H), 1.45 (s, 1 H), 2.12-1.05 (series of multiplets, 27 H), 0.96 (s, 3 H), 0.84 (d, J=10.5 Hz, 3 H), 0.78 (s, 3 H); 13C NMR (CDCl3 and ˜10% CD3OD, 125 MHz) δ 174.19, 170.05, 169.87, 156.21, 79.36, 79.27, 76.06, 76.90, 71.80, 61.19, 57.04, 46.88, 44.87, 44.67, 44.53, 42.78, 42.15, 42.01, 40.43, 37.47, 34.32, 34.11, 33.92, 33.35, 33.25, 30.74, 30.56, 30.16, 28.40, 27.67, 27.62, 26.73, 26.19, 25.18, 25.10, 24.72, 24.49, 22.29, 21.81, 16.76, 11.56; FAB-MS (thioglycerol+Na+ matrix) m/e: ([M+Na]+) 973.5723 (100%), calcd. 973.5725. The white solid from the previous reaction (0.680 g, 0.714 mmol) and MeI (1 M in CH2Cl2, 1.5 mL) were stirred together for 2 h. The solvent and excess MeI were removed in vacuo giving a white solid (0.812 g 100%). The product was carried on without further purification. Representative synthesis of compounds 324-326: Compound 319 (0.812 g, 0.714 mmol) was dissolved in CH2Cl2 (5 mL) and trifluoroacetic acid (0.5 mL) was added. The mixture was stirred for 16 min. The solvent and excess acid were removed in vacuo, and the resulting oil was chromatographed (silica gel, CH2Cl2/MeOH/NH3—H2O 4:4:1) to give the desired product as a pale glass (0.437 g, 90% yield). Addition of HCl (2 M in ethyl ether, 2.5 mL) gave the trihydrochloride salt of 324 as a pale yellow powder. Compound 324: 1H NMR (50% CDCl3, 50% CD3OD, 300 MHz) δ 5.43 (s, 1H), 5.24 (s, 1 H), 4.84 (m, 1 H), 4.66 (m, 2 H), 4.16-3.96 (series of multiplets, 6 H), 3.88 (m, 2 H), 3.37 (s, 9 H), 0.67 (s, 3 H), 0.59 (d, J=6.3 Hz, 3 H), 0.56 (s, 3 H); 13C NMR (50% CDCl3, 50% CD3OD, 75 MHz) δ 173.47, 167.06, 167.01, 166.70, 78.01, 76.49, 73.78, 64.98, 57.67, 53.36, 47.49, 46.99, 45.61, 43.28, 40.83, 40.23, 40.10, 37.69, 34.80, 34.48, 34.28, 31.03, 30.63, 30.44, 28.94, 27.05, 26.56, 25.50, 22.53, 21.56, 16.95, 11.37; FAB-MS (thioglycerol+Na+ matrix) m/e: ([M−I]+) 665.4475 (85;6%), cacld 665.4489. Compounds 325 and 326 proved too unstable to chromatograph using the basic eluent used for the purification of 324. Consequently, 325 and 326 were prepared by deprotection of 320 and 321 using HCl (2 M in diethyl ether), followed by tituration with ethyl acetate. The compounds were then used without further purification. 1H NMR spectroscopy indicated that compounds 325 and 326 were >95% pure. Compound 325: 1H NMR (50% CDCl3, 50% CD3OD, 500 MHz) δ 5.21 (s, 1 H), 5.02 (d, J=4 Hz, 1 H), 4.64 (m, 1 H), 4.53 (m, 2 H), 3.74 (m, 2 H), 3.31-3.01 (series of multiplets, 6 H), 3.23 (s, 9 H), 2.96-2.73 (series of multiples, 6 H), 2.51-2.44 (m, 1 H), 2.35-2.29 (m, 1 H), 2.14-1.09 (series of multiplets, 26 H), 0.99 (s, 3 H), 0.85 (d, J=6.5 Hz, 3 H), 0.80 (s, 3 H); 13C NMR (50% CDCl3, 50% CD3OD, 125 MHz) δ 172.77, 169.88, 169.56, 169.50, 75.94, 74.44, 71.57, 64.31, 56.94, 52.92, 46.78, 44.59, 42.70, 40.21, 37.16, 34.80, 34.72, 34.66, 34.05, 34.00, 33.78, 33.62, 30.95, 30.91, 30.81, 30.41, 29.96, 29.81, 28.20, 26.37, 26.06, 24.74, 24.24, 22.04, 21.13, 16.54, 10.97; FAB-MS (thioglycerol+Na+ matrix) m/e: ([M−I]+) 707.4958 (25.6%), cacld 707.4958. Compound 326: 1H NMR (50% CDCl3, 50% CD3OD, 500 MHz) δ 5.12 (s, 1 H), 4.94 (d, J=2.5 Hz, 1 H), 4.56 (m. 1 H), 4.51 (t, J=2.3 Hz, 2 H), 3.74 (m, 2 H), 3.23 (s, 9 H), 3.05-3.01 (m, 4 H), 2.98 (t, J=7.5 Hz, 2 H), 2.63-2.43 (series of multiplets, 6 H), 2.31-2.24 (series of multiplets, 2 H), 2.07-1.87 (series of multiplets, 12 H), 1.17-1.05 (series of multiplets, 23 H), 0.94 (s, 3 H), 0.82 (d, J=6.0 Hz, 3 H), 0.76 (s, 3 H); 13C NMR (50% CDCl3, 50% CD3OD, 125 MHz) δ 171.87, 169.79, 169.59, 169.50, 76.12, 74.70, 71.65, 65.57, 65.08, 64.40, 57.68, 53.74, 52.78, 45.33 43.54, 41.04, 39.12, 37.92, 43.85, 34.72, 34.56, 34.34, 32.30, 31.47, 31.27, 30.87, 30.58, 29.03, 27.053, 26.84, 25.51, 24.95, 24.91, 22.87, 22.82, 22.65, 21.93, 17.31, 11.81; FAB-MS (thioglycerol+Na+ matrix) m/e: ([M−I]+) 749.5432 (100%), cacld 749.5436. Example 14 Stability Tests of Compounds 352-354 Compounds 352-354 were dissolved in 50 mM phosphate buffered water (pH 2.0, 7.0 or 12.0) at approximately 10 mM concentrations. The structures of compounds 352-354 are given in FIG. 9. Decomposition of the compounds was observed via HPLC (cyano-silica column, 0.15% TFA water-acetonitrile gradient elution). Table 15 shows the stabilities (half-lives) of compounds 352-354 in phosphate buffer at room temperature, pH 2.0, pH 7.0 and pH 12.0. These compounds were used since they contain a chromophore that facilitated monitoring of decomposition by absorption methods common in the HPLC apparatus used. At low pH, the amines are expected to be protonated and the compounds showed relative stability. At higher pH, the amines were less strongly protonated and became involved in ester hydrolysis. The γ-aminobutyric acid-derived compound was especially susceptible to hydrolysis, presumably yielding pyrrolidone. In general, the compounds are believed to hydrolyse to give cholic acid, choline or octanol, and glycine, beta-alanine, or pyrrolidone, depending on the particular compound. Decomposition through ester hydrolysis yielded compounds that were less polar and easily separable from the starting compounds. Initially, only one benezene-containing decomposition product was observed; at longer reaction times, two other decomposition products were observed which presumably corresponded to sequential ester hydrolysis. Example 15 Further Syntheses of Compounds of Formula I Compounds of formula I can also be prepared as shown in the following scheme. Alterations in the stereochemistry within the steroid (AB ring juncture in this case) Alterations in the saturation within the steroid (AB ring juncture in this case) Alterations in the number of hydroxyl groups on the steroid (OH-12 in this case) Alterations in other groups on the steroid (in the A ring in this case) Descriptions of the steroid starting materials shown above can be found in Dictionary of Steroids, Hill, R. A.; Kirk, D. N.; Makin, H. L. J.; Murphy, G. M., eds., Chapman and Hall: New York, 1991. Example 15 Testing of Compounds With Gram-Negative Bactenra MIC and MBC Measurements General: Microorganisms. Reference strains were purchased from the American Type Culture Collection (Rockville, Md.) or Bactrol disks from Difeo Laboratories (Detroit, Mich.). The following specific ATCC strains were used: 10798 Escherichia coli, 25922 Escherichia coli, 13883 Klebsiella pneumoniae, 27853 Pseudomonas aeruginosa, 14028 Salmonella typhimurium, 29212 Enterococcus faecalis, 25923 Staphylococcus aureus, 19615 Streptococcus pyogenes, and 90028 Candida albicans. Bacterial strains were maintained on Mueller-Hinton agar plates, and Candida albicans was maintained on Sabouraud Dextrose agar plates. Tryptic soy broth (TSB) was made by dissolving 27.5 grams of tryptic soy broth without dextrose (DIFCO Laboratories) in 1 liter of deionized water and sterilizing at 121° C. for 15 minutes. Solid agar (TSA) plates were made by dissolving 6.4 grams of tryptic soy broth and 12 grams of agar (purified grade, Fischer Scientific) in 800 mL of deionized water and sterilizing at 121° C. for 20 minutes. Aliquots (20 mL) of the homogeneous solution were then poured in sterile plastic petri dishes (100×15 mm, Fisher Scientific). Solutions of compounds were made by dissolving the HCl salt of the respective compound into an appropriate amount of deionized and sterilized water followed by microfiltration. Representative procedure for measuring MIC and MBC values: A suspension was prepared of E. coli (ATCC 10798) containing ˜106 CFU (colony forming units)/mL from a culture incubated in TSB at 37° C. for 24 hours., Aliquots of 1 mL of the suspension were added to test tubes containing 1 mL TSB and incrementally varied concentrations of cholic acid derivatives and/or erythromycin or novobiocin. In the sensitization experiments, erythromycin or novobiocin were added 15 minutes later than the cholic acid derivatives. The samples were subjected to stationary incubation at 37° C. for 24 hours. Sample turbidity was determined by measuring absorption at 760 nm (HP 8453 UV-Visible Chemstation, Hewlett Packard). Additionally, an alliquot from each of the samples showing no measurable turbidity was subcultured on TSA plates (alliquots were diluted to provide fewer than 300 CFU). Colonies that grew on the subculture after overnight incubation were counted and the number of CFU/mL in the samples were calculated. The calculated values were compared to the number of CFU/mL in the original inoculum. MIC values were determined as the concentrations of the studied compounds at which the number of CFU/mL remained constant or decreased after incubation for 24 hours. The MBC values were determined as the lowest concentrations of the studied compounds that allowed less than 0.1% of the original bacterial suspension to survive. Example 16 Demonstration of Membrane Disrupting Properties of the Cholic Acid Derivatives Using a technique described by J. M. Shupp, S. E. Travis, L. B. Price, R. F. Shand, P. Keim, RAPID BACTERIAL PERMEABILIZATION REAGENT USEFUL FOR ENZYME ASSAYS, Biotechniques, 1995, vol. 19, 18-20, we have shown that the cholic acid derivatives increase the permeability of the outer membrane of Gram-negative bacteria. The values for half maximum luminescence (indicating permeabilization of the outer membrane allowing luciferin to enter the cell) for 2 is 7 μg/mL and for 10 is 33 μg/mL. These values correspond to the measured MICs of 2 and 10. PMB is known to have membrane permeabilization and bactericidal properties. PMB has a hydrophobic acyl group and a macrocylic heptapeptide containing a D amino acid and four diaminobutyric acid (DAB) residues. One of the DAB side chains is involved in forming the macrocylic ring, leaving the other three side chains with free amines. Thus, PMB has an array of amines oriented on one face, or plane, of a hydrophobic scaffolding. It has been suggested that the primary role of the macrocylic ring is to orient the amine groups in a specific arrangement necessary for binding the lipid A portion of LPS. The relative spatial orientation of these primary amine groups is the same in the cholic acid derivatives as in PMB. The stereochemistry of the steroid backbone results in different activities of the cholic acid derivatives (compare 2 and 8, Tables 1, 2, 6 and 7). Compounds with guanidine groups attached to the steroid have lower MIC values than compounds containing amine groups (compare 1, 2, 4 and 5, compare Tables 1-8). The length of the tether between the amine or guanidine groups and the steroid backbone also influences activity (compare 1-3, Tables 1, 2, 6 and 7). Ester tethers between amine groups and the steroid backbone provide compounds with MIC values that are higher than the corresponding compounds containing ether tethers (compare 1, 2, 6 and 7, tables 1 and 2). The group attached to the backbone at C-20 or C-24 also influences the activity of the cholic acid derivatives. A long carbon chain attached to the steroid via an ether linkage at C-24 lowers the MIC of the compound as compared to the compound with a hydroxyl group at C-24 (compare 2, 9 and 10, Tables 1, 2, 6 and 7). Short chains of carbon or oxygen attached at C-20 decrease the MIC values of the cholic acid derivatives (compare 10 and 11, Tables 1 and 2). Covalently linking the cholic acid derivatives increases the activity of the compounds (compare 10 and 12, Tables 1 and 2). Ability to permeabilize outer membrane: Compounds 11, 106, and 108-114 (FIG. 1) were tested for antibiotic activity. They were also tested for the ability to permeabilize the outer membrane of Gram-negative bacteria, causing sensitization to hydrophobic antibiotics that cannot cross the outer membrane. The permeabilization of the outer membrane was measured using erythromycin and novobiocin. These antibiotics are active against Gram-positive bacteria, but inactive against Gram-negative bacteria, due to the barrier formed by the outer membrane of Gram-negative bacteria. Most of the experiments were performed with Escherichia coli K-12 strain ATCC 10798; however, to demonstrate that the activity of the cholic acid derivatives was not species dependent, the activity of selected compounds was also measured with Pseudomonas aeruginosa (ATCC 27853). The MICs of erythromycin and novobiocin against E. coli (ATCC 10798) at 70 and >500 μg/mL were measured. The threshold measure of permeabilization was the concentration of the cholic acid derivatives required to lower the MIC of either erythromycin or novobiocin to 1 μg/mL. Results of the MIC, MBC and permeabilization (with erythromycin) measurements are shown in FIG. 2 (in FIG. 2, Compound A is polymyxin B nonapeptide). As FIG. 2 illustrates, the MIC and MBC values of the compounds dropped dramatically as the length of the side chain extending from C-17 increased. The apparent role of the hydrophobic steroid side chain is to facilitate membrane insertion and self-promoted transport after initial association with the outer membrane of Gram-negative bacteria (as shown in FIG. 3). Outer membrane permeabilization occurs as a result of association with the lipid A on the outer leaflet of the membrane. Permeabilization of the outer membrane alone does not cause cell death, suggesting that the compounds must pass through the outer membrane to kill bacteria. This ability to traverse the outer membrane, and thereby disrupt the cytoplasmic membrane, is required for the compounds to have lethal activity. As observed, compounds lacking a hydrophobic side chain are less effective in killing bacteria. It is hypothesized that these compounds are capable of permeabilizing the outer membrane (i.e., associating with the lipid A on the outer leaflet of the membrane), but incapable of crossing through the outer membrane. The fractional inhibition concentration (FIC) values of the compounds, were calculated using erythromycin and novobiocin as the secondary compounds. With the exception of 114, the compounds displayed FIC values of less than 0.5 with erythromycin, with some values near 0.05 (Table 9). Details from studies with novobiocin are also shown in Table 9. The fact that results with erythromycin and novobiocin were comparable demonstrates that the activity of the cholic acid derivatives is not antibiotic-dependent. Similar trends were observed with E. coli (ATCC 10798) and P. aeruginosa (ATCC 27853), although, as expected, P. aeruginosa was more resistant than E. coli. These results suggest that the activity of the compounds tested is not species-dependent. Compounds with hydrophobic alkylaminoalkyl side chains were prepared (compounds 133 and 134, FIG. 4). As observed with other compounds, the incorporation of guanidine groups (in 134) increased the activity of the cholic acid derivatives as compared to compounds containing primary amines. As a control, 135 (FIG. 4), which did not have a hydrophobic side chain, was prepared. The MIC of the control (135) was relatively high, as expected, as was the MBC (FIG. 5). In contrast, the MICs of 133 and 134 were very low; in fact they rivaled PMB in activity. Notably, the MBCs of 133, 134, and PMB were very similar to the MICs; that is, at a threshold concentration these compounds killed all of the bacteria in solution. As an additional means of demonstrating the membrane disrupting capabilities of the cholic acid derivatives 133 and 134, a luciferin/luciferase-based cell lysis assay was used (as described in Willardson et al., Appl. Environ. Microbiol. 1998, 64, 1006 and Schupp et al., Biotechniques 1995, 19, 18). In this assay, E. coli containing an inducible luciferase coding plasmid was incubated with the inducing agent (toluene), then treated with a lysis buffer containing either PMB or one of the cholic acid derivatives, and Triton X-100. Luciferin and ATP were then added. Cell lysis resulted in luminescence. The concentrations of the membrane disrupting agents (PMB and the cholic acid derivatives) were varied, and the resulting luminescence was measured. In the absence of the membrane disrupting agents, no luminescence was observed. The MICs of 133, 134 and. PMB and the concentrations required for half maximal luminescence are shown in FIG. 6. As is the case with the MIC values, the compounds 133 and 134 rival PMB in activity in the luminescence assay. Effect of sulfate group: To observe if the presence of a sulfate group at C-24 in a cholic acid derivative would increase the activity of the compounds, 132 (shown in FIG. 7) was tested. The MIC of 132 with E. coli (ATCC 10798) was 60 μg/mL. The concentration required to lower the MIC of erythromycin to 1 μg/mL was 4.0 μg/mL with the same strain. The antibiotic and permeabilization activities of 132 were lower than those of the parent alcohol 110 (shown in FIG. 1). Additional experiments: Additional experiments were carried out using compounds 1, 2, 5, 106, 10, 112, 133, and 134. MIC and MBC data for these compounds with representative strains of Gram-negative and Gram-positive organisms are shown in Table 10. For comparison purposes, the MICs of PMB with various organisms were also measured and are presented in Table 10. In addition to PMB, compounds 1, 2, 5, 106, 10, 112, 133, and 134 share some features with other steroid antibiotics. For example, squalamine includes a steroid nucleus and a polyamine side chain (Moore et al., Proc. Natl. Acad. Sci. 1993, vol. 90, 1354-1358). It is proposed that squalamine incorporates into lipid bilayers and thus disrupts the bacterial membrane. In squalamine, the polar polyamine functionality is located at the distal end of the molecule, leaving a hydrophobic core. In 1, 2, 5, 106, 10, 112, 133, and 134, the amines are located on one side of the steroid, giving compounds that are facially anphiphilic. An additional series of compounds related to 1, 2, 5, 106, 10, 112, 133, and 134 includes cholic acid derivatives with amines at C-24 (e.g., 140 in FIG. 7). In contrast to 1, 2, 5, 106, 10, 112, 133, and 134, these compounds have been shown to have only weak antibacterial activity against Gram-positive strains and no activity against Gram-negative strains. The cholic acid derivatives 1, 2, 5, 106, 10, 112, 133, and 134 display a range of activities, some with submicrogram per milliliter MICs. With many organisms, MIC and MBC values are very similar, especially with the most active compounds. Some of the compounds have lethal activity, presumably due to disruption of the cytoplasmic membrane. Others have only sublethal activity, due to permeabilization of the outer membrane. Compounds lacking a hydrophobic chain (e.g., 106 and 10) have high MIC values, but are effective permeabilizers of the outer membrane of Gram-negative bacteria. Because these compounds lack a hydrophobic chain, they have sublethal, but not lethal activity against these bacteria. Compounds with hydrophobic chains (e.g., 133 and 134) have lethal activity. The hemolytic behavior of the cholic acid derivatives 1, 2, 5, 106, 10, 112, 133, and 134 suggests that they can act as membrane-disrupting agents, and their antimicrobial activity likely involves membrane disruption. With Gram-negative strains, the target of inactivity is expected to be the cytoplasmic membrane., Compounds such as 106 and 10 ineffectively cross the outer membrane and do not display lethal activity. The hydrophobic chains in 133 and 134 may facilitate self-promoted transport across the outer membrane, allowing them to disrupt the cytoplasmic membrane. The results shown in Table 10 indicate that the presence of a hydrophobic chain is much less important for lethal activity against Gram-positive strains. Without the requirement for crossing an outer membrane, compounds lacking a hydrophobic chain extending from C-17 can effectively kill Gram-positive bacteria. Various tether lengths were investigated to determine the optimal spacing of the amine or guanidine groups from the steroid. It was found that three carbon tethers gave compounds that were more effective than those with two carbon tethers (e.g., compare the MICs of 1 with those of 2. The resultant increase in antibiotic activity upon substitution of guanidine groups for amines suggests a central role for amine/guanidine-phosphate interactions. The nature of the group attached to the steroid backbone at C-17 greatly influenced the activity of the compounds with Gram-negative bacteria. For example, the differences among the MIC and MBC values for 106, 10, and 112 were notable. This trend was also observed in the MIC and MCB values of 2 and 5, as compared to those of 133 and 134 (in this comparison, the benzyl groups in 2 and 5 are expected to be less hydrophobic than the octyl chains found in 133 and 134). The influence of the group attached to the steroid at C-17 is less pronounced with Gram-positive strains; e.g., 5 and 134 have similar MIC values with Staphylococcus aureus. To measure permeabilization, the FIC values for compounds 1, 2, 5, 106, 10, 112, 133, and 134 with erythromycin, novobiocin, and rifampicin were determined. Concentrations of 0.5, 1.0 or 3.0 μg/mL of these antibiotics were used, and the concentrations of the cholic acid derivatives required to inhibit bacterial growth of Gram-negative strains were determined. The concentrations required for bacterial growth inhibition and the FIC values are shown in Tables 11-13. Interestingly, the MIC values of the compounds do not directly correlate with their ability to permeabilize the outer membrane. For example, compounds 106 and 10 have relatively high MIC values, but are potent permeabilizers. Nearly all of the compounds demonstrated FIC values of less than 0.5, with some less than 0.03. The cholic acid derivatives that give relatively high FIC values (i.e., 5, 133, and 134) are themselves potent antibiotics. Ester and amide side chains: Additional compounds, for example, compounds with amide and ester side chains, were tested. Compounds 203b, 6, and 210a (Scheme 12) displayed potent synergism with erythromycin and novobiocin (Table 14). In the triester series (203a, 203b, 6, and 7), the β-alanine derived compounds are more active than those derived from glycine. Substitution at C24 had minimal effect on the activity of these compounds (compare 203b and 7). Triamides 209a-c (Scheme 12) were less active than the esters, possibly due to conformational constraints imposed by the amide bonds. With the triamides, substitution at C24 had significant effects on the activity of the compounds (compare 209a and 210a, Table 14). In this series, the glycine derivative was more active than the corresponding β-alanine derivative. The relative lack of synergism displayed by the lysine derivative may be attributable to the length of the side chain. As a control, compound 211 (FIG. 8), a derivative of 209c lacking the α-amino group, was prepared; this compound was less active than 209c as a permeabilizer. Compound 206 also proved to be ineffective as a permeabilizer. These results suggest that the optimal length for the tether between the steroid and the amine functionality is between zero and six atoms. Further compounds 341-343 and 324-327 were, investigated similarly. The structures of compounds 341-343 and 324-327 are shown in FIG. 11. The MIC of these compounds against S. aureus (ATTC 25923) are presented in Table 16 as MICa, the MIC of these compounds against E. coli (ATTC 25922) are presented in Table 16 as MICb, the concentration of the compounds required to lower the MIC of erythromycin from 36 to 1 μg/mL with E. coli is shown in Table 16 as c, and the minimum hemolytic concentration of the compounds is shown in Table 16 as MHCd. Minimum inhibition concentrations (MIC) and minimum hemolytic concentrations (MHC) were measured as described in Li et al., Antimicrob. Agents. Chemother., 1999, 43, 1347. The compounds in Table 16 containing a hydrophobic chain at carbon 24 (341-343) were the most active against the Gram-negative strain. The compounds with choline at carbon 24 (324-326) were much less active alone against the Gram-negative strain, yet retained the ability to inhibit the growth of the Gram-positive strain. This difference may be due to the inability of compounds 324-326 to traverse the ourter membrane of the Gram-negative strain studied here. Compound 327 was inactive. Compounds 341-343 exhibited very low MHC; however, compounds 324-326 appear to be non-hemolytic, presumably due to the additional positive charge at carbon 24. The structures of compounds 356-358 are shown in FIG. 12. An outline of the synthesis of compounds 356-357 is shown in Scheme 16. TABLE 1 Measurement of MIC and MBC values of 1-12 with E. coli (ATCC 10798) Compound MIC (μg/mL) MBC (μg/mL) 1 20 34 2 7 16 3 6 a 4 5 10 5 2 4 6 65 a 7 28 a 8 46 a 9 3 10 10 36 60 11 140 >160 12 4 4 aValue not measured. TABLE 2 Measurement of the concentrations of 1-12 required to lower the MIC of erythromycin from 70 μg/mL to 1 μg/mL with E. coli (ATCC 10798). Compound MIC (μg/mL) MBC (μg/mL) 1 2 20 2 1 10 3 1.5 a 4 1.5 10 5 1 3 6 22 a 7 2.5 a 8 10 a 9 3 3 10 2 50 11 40 >160 12 1.5 2.5 aValue not measured. TABLE 3 Measurement of the concentrations of 1, 2, 4 and 5 required to lower the MIC of novobiocin from >500 μg/mL to 1 μg/mL with E. coli (ATCC 10798). Compound MIC (μg/mL) MBC (μg/mL) 1 20 34 2 7 16 4 5 10 5 2 4 11 40 140 12 2.5 a aValue not measured. TABLE 4 Measurement of MIC and MBC values of 1, 2, 4 and 5 with E. coli (ATCC 25922). Compound MIC (μg/mL) MBC (μg/mL) 1 25 40 2 10 20 4 6 9 5 2 4 TABLE 5 Measurement of the concentrations of 1, 2, 4 and 5 required to lower the MIC of erythromycin from 60 μg/mL to 1 μg/mL with E. coli (ATCC 25922). Compound MIC (μg/mL) MBC (μg/mL) 1 2 14 2 1 5 4 1 5 5 1.5 1.5 TABLE 6 Measurement of MIC and MBC values of 1-5, 8-12 with P. aureginosa (ATCC 27853). Compound MIC (μg/mL) MBC (μg/mL) 1 15 >50 2 9 40 3 16 a 4 15 40 5 6 15 8 50 a 9 8 a 10 23 a aValue not measured. TABLE 7 Measurement of the concentrations of 1-5, 8-12 required to lower the MIC of erythromycin from 240 μg/mL to 5 μg/mL with P. aureginosa (ATCC 27853). Compound MIC (μg/mL) MBC (μg/mL) 1 8 45 2 4 25 3 6 a 4 5 40 5 3 10 8 40 a 9 5 a 10 7 a aValue not measured. TABLE 8 Measurement of the concentrations of 1, 2, 4 and 5 required to lower the MIC of novobiocin from >500 μg/mL to 1 μg/mL with P. aureginosa (ATCC 27853). Compound MIC (μg/mL) 1 6 2 4 4 6 5 6 TABLE 9 Com- MIC MBC (a) (b) (d) pound (μg/mL) (μg/mL) (μg/mL) (μg/mL) FICc (μg/mL) FICe 106 140 >200 30 160 0.23 50 0.36 11 140 >160 20 180 0.16 40 0.29 108 70 140 4.0 140 0.071 12 0.17 109 70 120 4.0 80 0.071 15 0.22 110 36 60 2.0 50 0.070 4.0 0.11 111 30 33 1.0 20 0.048 2.0 0.069 112 12 17 0.4 4.0 0.048 0.8 0.085 113 3.0 5.0 0.8 2.0 0.28 1.0 0.27 114 3.0 10 3.0 3.0 1.0 n.d. n.d. MIC, MBC, permeabilization and FIC data with Escherichia coli (ATCC 10798). (a) Concentration required to lower the MIC of erythromycin from 70 to 1 μg/mL. (b) MBC with 1 μg/mL erythromycin. cFIC values with erythromycin. (d) Concentration required to lower the MIC of novobiocin from >500 to 1 μg/mL. eFIC values with novobiocin. TABLE 10 1 (μg/mL) 2 (μg/mL) 5 (μg/mL) 106 (μg/mL) 10 (μg/mL) 112 (μg/mL) 133 (μg/mL) 134 (μg/mL) PMB (1) ORGANISM MIC MBC MIC MBC MIC MBC MIC MBC MIC MBC MIC MBC MIC MBC MIC MBC MIC MBC Gram-negative rods Escherichia 22 22 5.1 6.8 1.4 3.8 80 90 36 40 6.6 7.4 3.0 3.0 0.31 0.37 1.8 1.8 coli ATCC 25922 Klebsiella 24 >36 14 17 3.0 6.7 >100 100 47 50 23 27 2.6 5.8 0.84 3.0 5.3 6.8 pneumonia ATCC 13883 Pseudomonas 26 38 11 >17 5.9 9.9 85 97 21 36 4.6 6.4 2.0 3.2 2.0 2.9 0.20 3.9 aeruginosa ATCC 27853 Salmonella 21 >25 13 16 2.2 3.8 >100 >100 43 >17 86 90 2.6 6.7 0.81 1.8 nm nm typhimurium ATCC 14028 Gram-positive coccl Enterococcus 4.9 50 3.4 19 2.2 16 12 >100 3.3 19 3.1 4.7 3.1 5.5 3.0 5.8 40 >100 faecalis ATCC 29212 Staphylococcus 3.1 5.7 1.0 4.7 0.6 3.2 8.6 54 2.0 9.2 0.55 4.2 0.4 2.0 0.59 1.4 26 >100 aureus ATCC 25923 Streptococcus 3.0 4.4 2.0 2.3 2.0 2.1 18 37 4.2 5.8 2.4 3.0 2.3 2.9 3.5 3.5 9.0 16.3 pyrogenes ATCC 19615 Candida 49 >50 30 42 11 50 75 92 14 29 41 45 31 45 53 76 albicans ATCC 90028 MHC 78 58 26 >100 100 5.9 29 9.0 TABLE 11 1 2 5 106 10 112 133 134 μg/ μg/ μg/ μg/ μg/ μg/ μg/ μg/ ORGANISM a mL FIC mL FIC mL FIC mL FIC mL FIC mL FIC mL FIC ml FIC Escherichia coli 30 2.5 0.15 0.23 0.078 0.38 0.31 3.2 0.073 1.5 0.074 0.59 0.12 1.2 0.42 0.37 0.36 ATCC 25922 Klebsiella 33 1.0 0.072 0.25 0.048 0.15 0.080 3.6 0.66 0.21 0.035 0.1 0.035 0.11 0.073 0.18 0.24 pneumonia ATCC 13883 Pseudomonas >100 6.6 0.29 2.4 0.25 2.3 0.42 16 0.22 2.1 0.13 1.0 0.59 0.35 0.21 0.70 0.42 aeruginosa ATCC 27853 Salmonella 61 3.6 0.19 2.0 0.17 0.46 0.23 7.1 0.088 0.87 0.037 0.20 0.019 0.72 0.29 0.34 0.44 typhimurium ATCC 14028 TABLE 12 1 2 106 10 112 ORGANISM a μg/mL FIC μg/mL IC μg/mL FIC μg/mL FIC μg/mL FIC Escherichia coli 41 0.35 0.041 0.33 0.089 4.7 0.084 0.30 0.033 0.40 0.085 ATCC 25922 Klebsiella pneumonia 75 4.7 0.21 0.49 0.048 8.9 0.10 0.73 0.029 0.19 0.022 ATCC 13883 Pseudomonas aeruginosa >100 3.9 0.16 2.9 0.27 30 0.36 5.3 0.26 0.72 0.17 ATCC 27853 Salmonella typhimurium >100 4.4 0.22 4.5 0.36 8.4 0.094 1.8 0.052 0.39 0.015 ATCC 14028 TABLE 13 1 2 106 10 112 ORGANISM a μg/mL FIC μg/mL IC μg/mL FIC μg/mL FIC μg/mL FIC Escherichia coli 7.6 0.74 0.099 0.80 0.22 4.2 0.12 0.70 0.085 0.81 0.19 ATCC 25922 Klebsiella pneumonia 19 0.40 0.043 0.12 0.035 1.8 0.044 0.16 0.030 0.11 0.031 ATCC 13883 Pseudomonas aeruginosa 26 1.5 0.096 0.50 0.086 11 0.17 0.84 0.083 0.50 0.15 ATCC 27853b Salmonella typhimurium 21 0.84 0.089 0.39 0.079 1.4 0.064 0.55 0.063 0.10 0.051 ATCC 14028b TABLE 14 MIC Compound (μg/mL) a (μg/mL) b (μg/mL) 203a 85 18 55 203b 80 4 10 6 85 15 40 7 70 3 13 209a >100 25 75 209b >100 40 75 209c 85 45 60 210a 80 6 18 210b 100 15 40 a: concentration of cholic acid derivatives required to lower MIC of erythromycin to 1 μg/ML. b: concentration of cholic acid derivatives required to lower MIC of novobiocin to 1 μg/ML. TABLE 15 Compound pH 2.0 pH 7.0 pH 12.0 352 >37 days 28 days <30 minutes 353 >37 days 37 days <30 minutes 354 33 days 12 days <30 minutes TABLE 16 MIC MIC MHC Compound (μg/mL) (μg/mL) c (μg/mL) (μg/mL) 341 1.8 1.0 0.7 4.0 342 4.0 7.0 3.0 2.0 343 1.2 3.5 3.5 <10 324 15 60 10 >200 325 11 30 2.0 >200 326 14 23 2.0 >200 327 >100 >100 >100 >100 Other Embodiments All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features. From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. For examples, salts, esters, ethers and amides of novel steroid compounds disclosed herein are within the scope of this invention. Thus, other embodiments are also within the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The invention relates to novel steroid derivatives and processes and intermediates for the preparation of these compounds. Some compounds that associate strongly with the outer membrane of Gram-negative bacteria are known to disrupt the outer membrane and increase permeability. The increased permeability can increase the susceptibility of Gram-negative bacteria to other antibiotics. The best studied of this type of compound are the polymyxin antibiotics. For an example of a study involving the binding of polymyxin B to the primary constituent of the outer membrane of Gram-negative bacteria (lipid A) see: D. C. Morrison and D. M. Jacobs, Binding of Polymyxin B to The Lipid a Portion of Bacterial Lipopolysaccharides , Immunochemistry 1976, vol. 13, 813-819. For an example of a study involving the binding of a polymyxin derivative to Gram-negative bacteria see: M. Vaara and P. Viljanen, Binding of Polymyxin B Nonapeptide to Gram - negative Bacteria , Antimicrobial Agents and Chemotherapy, 1985, vol. 27, 548-554. Membranes of Gram-negative bacteria are semipermeable molecular “sieves” which restrict access of antibiotics and host defense molecules to their targets within the bacterial cell. Thus, cations and polycations which interact with and break down the outer membrane permeability barrier are capable of increasing the susceptibility of Gram-negative pathogenic bacteria to antibiotics and host defense molecules. Hancock and Wong demonstrated that a broad range of peptides could overcome the permeability barrier and coined the name “permeabilizers” to describe them (Hancock and Wong, Antimicrob. Agents Chemother., 26:48, 1984). | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention features compounds of the formula I wherein: fused rings A, B, C, and D are independently saturated or fully or partially unsaturated; and each of R 1 through R 4 , R 6 , R 7 , R 11 , R 12 , R 15 , R 16 , and R 17 is independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—C(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid (including the side chain of glycine, i.e., H), P.G. is an amino protecting group, and R 5 , R 8 , R 9 , R 10 , R 13 , and R 14 is each independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, and provided that at least two of R 1 through R 14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof. The term fused ring used herein can be heterocyclic or carbocyclic, preferably. The term “saturated” used herein refers to the fused ring of formula I having each atom in the fused ring either hydrogenated or substituted such that the valency of each atom is filled. The term “unsaturated” used herein refers to the fused ring of formula I where the valency of each atom of the fused ring may not be filled with hydrogen or other substituents. For example, adjacent carbon atoms in the fused ring can be doubly bound to each other. Unsaturation can also include deleting at least one of the following pairs and completing the valency of the ring carbon atoms at these deleted positions with a double bond; such as R 5 and R 9 ; R 8 and R 10 ; and R 13 and R 14 . The term “unsubstituted” used herein refers to a moiety having each atom hydrogenated such that the valency of each atom is filled. The term “halo” used herein refers to a halogen atom such as fluorine, chlorine, 0.10 bromine, or iodine. Examples of amino acid side chains include but are not limited to H (glycine), methyl (alanine), —CH 2 —(C═O)—NH 2 (asparagine), —CH 2 —SH (cysteine), and —CH(OH)CH 3 (threonine). An alkyl group is a branched or unbranched hydrocarbon that may be substituted or unsubstituted. Examples of branched alkyl groups include isopropyl, sec-butyl, isobutyl, tert-butyl, sec-pentyl, isopentyl, tert-pentyl, isohexyl. Substituted alkyl groups may have one, two, three or more substituents, which may be the same or different, each replacing a hydrogen atom. Substituents are halogen (e.g., F, Cl, Br, and I), hydroxyl, protected hydroxyl, amino, protected amino, carboxy, protected carboxy, cyano, methylsulfonylamino, alkoxy, acyloxy, nitro, and lower haloalkyl. The term “substitued” used herein refers to moieties having one, two, three or more substituents, which may be the same or different, each replacing a hydrogen atom. Examples of substituents include but are not limited to halogen (e.g., F, Cl, Br, and I), hydroxyl, protected hydroxyl, amino, protected amino, carboxy, protected carboxy, cyano, methylsulfonylamino, alkoxy, alkyl, aryl, aralkyl, acyloxy, nitro, and lower haloalkyl. An aryl group is a C 6-20 aromatic ring, wherein the ring is made of carbon atoms (e.g., C 6-14 , C 6-10 aryl groups). Examples of haloalkyl include fluoromethyl, dichloromethyl, trifluoromethyl, 1,1-difluoroethyl, and 2,2-dibromoethyl. An aralkyl group is a group containing 6-20 carbon atoms that has at least one aryl ring and at least one alkyl or alkylene chain connected to that ring. An example of an aralkyl group is a benzyl group. A linking group is any divalent moiety used to link a compound of formula to another steroid, e.g., a second compound of formula I. An example of a linking group is (C1-C10) alkyloxy-(C1-C10) alkyl. Numerous amino-protecting groups are well-known to those in the art. In general, the species of protecting group is not critical, provided that it is stable to the conditions of any subsequent reaction(s) on other positions of the compound and can be removed at the appropriate point without adversely affecting the remainder of the molecule. In addition, a protecting group may be substituted for another after substantive synthetic transformations are complete. Clearly, where a compound differs from a compound disclosed herein only in that one or more protecting groups of the disclosed compound has been substituted with a different protecting group, that compound is within the invention. Further examples and conditions are found in T. W. Greene, Protective Groups in Organic Chemistry , (1st ed., 1981, 2nd ed., 1991). The present invention also includes methods of synthesizing compounds of formula I where at least two of R 1 through R 14 are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy. The method includes the step of contacting a compound of formula IV, where at least two of R 1 through R 14 are hydroxyl, and the remaining moieties on the fused rings A, B, C, and D are defined for formula I, with an electrophile to produce an alkyl ether compound of formula IV, wherein at least two of R 1 through R 14 are (C1-C10)alkyloxy. The alkyl ether compounds are converted into an amino precursor compound wherein at least two of R 1 through R 14 are independently selected from the group consisting of (C1-C10) azidoalkyloxy and (C1-C10) cyanoalkyloxy and the amino precursor compound is reduced to form a compound of formula I. The electrophiles used in the method include but are not limited to 2-(2-bromoethyl)-1,3-dioxolane, 2-iodoacetamide, 2-chloroacetamide, N-(2-bromoethyl)phthalimide, N-(3-bromopropyl)phthalimide, and allybromide. The preferred electrophile is allylbromide. The invention also includes a method of producing a compound of formula I where at least two of R 1 through R 14 are (C1-C10) guanidoalkyloxy. The method includes contacting a compound of formula IV, where at least two of R 1 through R 14 are hydroxyl, with an electrophile to produce an alkyl ether compound of formula IV, where at least two of R 1 through R 14 are (C1-C10)alkyloxy. The allyl ether compound is converted into an amino precursor compound where at least two of R 1 through R 14 are independently selected from the group consisting of (C1-C10) azidoalkyloxy and (C1-C10) cyanoalkyloxy. The amino precursor compound is reduced to produce an aminoalkyl ether compound wherein at least two of R 1 through R 14 are (C1-C10) aminoalkyloxy. The aminoalkyl ether compound is contacted with a guanidino producing electrophile to form a compound of formula I. The term “guanidino producing electrophile” used herein refers to an electrophile used to produce a guanidino compound of formula I. An example of an guanidino producing electrophile is HSO 3 —C(NH)—NH 2 . The invention also includes a method of producing a compound of formula I where at least two of R 1 through R 14 are H2N—HC(Q5)-C(O)—O— and Q5 is the side chain of any amino acid. The method includes the step of contacting a compound of formula IV, where at least two of R 1 through R 14 are hydroxyl, with a protected amino acid to produce a protected amino acid compound of formula IV where at least two of at least two of R 1 through R 14 are P.G.-HN—HC(Q5)-C(O)—O— and Q5 is the side chain of any amino acid and P.G. is an amino protecting group. The protecting group of the protected amino acid compound is removed to form a compound of formula I. The present invention also includes pharmaceutical compositions of matter that are useful as antibacterial agents, sensitizers of bacteria to other antibiotics and disrupters of bacterial membranes. The pharmaceutical compositions can be used to treat humans and animals having a bacterial infection. The pharmaceutical compositions can include an effective amount of the steroid derivative alone or in combination with other antibacterial agents. The invention further includes a method of preparing the compound (A): by (a) contacting 5β-cholanic acid 3,7,12-trione methyl ester with hydroxylamine hydrochloride and sodium acetate to form the trioxime (B): (b) contacting trioxime (B) with NaBH 4 and TiCl 4 to yield compound (A). The invention also includes a compound comprising a ring system of at least 4 fused rings, where each of the rings has from 5-7 atoms. The ring system has two faces, and contains 3 chains attached to the same face. Each of the chains contains a nitrogen-containing group that is separated from the ring system by at least one atom; the nitrogen-containing group is an amino group, e.g., a primary amino group, or a guanidino group. Preferably, the compound also contains a hydrophobic group, such as a substituted (C3-10) aminoalkyl group, a (C1-10) alkyloxy (C3-10) alkyl group, or a (C1-10) alkylamino (C3-10)alkyl group, attached to the steroid backbone. For example, the compound may have the formula V, where each of the three chains containing nitrogen-containing groups is independently selected from R 1 through R 4 , R 6 , R 7 , R 11 , R 12 , R 15 , R 16 , R 17 , and R 18 , defined below. where: each of fused rings A, B, C, and D is independently saturated, or is fully or partially unsaturated, provided that at least two of A, B, C, and D are saturated, wherein rings A, B, C, and D form a ring system; each of m, n, p, and q is independently 0 or 1; each of R 1 through R 4 , R 6 , R 7 , R 11 , R 12 , R 15 , R 16 , R 17 , and R 18 is independently selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted arylamino-(C1-C10) alkyl, (C1-C10) haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, oxo, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, a substituted or unsubstituted (C1-C10) aminoalkylcarboxamido, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyl oxy, (C1-C10) quaternaryammoniumalkylcarboxy, and (C1-C10) guanidinoalkyl carboxy, where Q5 is a side chain of any amino acid (including the side chain of glycine, i.e., H), P.G. is an amino protecting group; and each of R 5 , R 8 , R 9 , R 10 , R 13 , and R 14 is independently: deleted when one of fused rings A, B, C, or D is unsaturated so as to complete the valency of the carbon atom at that site, or selected from the group consisting of hydrogen, hydroxyl, a substituted or unsubstituted (C1-C10) alkyl, (C1-C10) hydroxyalkyl, (C1-C10) alkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyl, a substituted or unsubstituted aryl, C1-C10 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, a linking group attached to a second steroid, a substituted or unsubstituted (C1-C10) aminoalkyloxy, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy, where Q5 is a side chain of any amino acid, P.G. is an amino protecting group, provided that at least three of R 1 through R 4 , R 6 , R 7 , R 11 , R 12 , R 15 , R 16 , R 17 , and R 18 are disposed on the same face of the ring system and are independently selected from the group consisting of a substituted or unsubstituted (C1-C10) aminoalkyloxy, (C1-C10) alkylcarboxy-(C1-C10) alkyl, (C1-C10) alkylamino-(C1-C10) alkylamino, (C1-C10) alkylamino-(C1-C10) alkylamino-(C1-C10) alkylamino, a substituted or unsubstituted (C1-C10) aminoalkylcarboxy, a substituted or unsubstituted arylamino-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkyloxy-(C1-C10) alkyl, a substituted or unsubstituted (C1-C10) aminoalkylaminocarbonyl, (C1-C10) quaternaryammonium alkylcarboxy, H2N—HC(Q5)-C(O)—O—, H2N—HC(Q5)-C(O)—N(H)—, (C1-C10) azidoalkyloxy, (C1-C10) cyanoalkyloxy, P.G.-HN—HC(Q5)-C(O)—O—, (C1-C10) guanidinoalkyloxy, and (C1-C10) guanidinoalkylcarboxy; or a pharmaceutically acceptable salt thereof. Preferably, at least two, or at least, three, of m, n, p, and q are 1. Without wishing to be bound to any particular theory, the steroid derivatives described herein act as bacteriostatic and bactericidal agents by binding to the outer cellular membrane of bacteria. The interaction between the steroid derivatives and the bacteria membrane disrupts the integrity of the cellular membrane and results in the death of the bacteria cell. In addition, compounds of the present invention also act to sensitize bacteria to other antibiotics; At concentrations of the steroid derivatives below the corresponding minimum bacteriostatic concentration, the derivatives cause bacteria to become more susceptible to other antibiotics by increasing the permeability of the outer membrane of the bacteria. Measurements used to quantitate the effects of the steroid derivatives on bacteria include: measurement of minimum inhibitory concentrations (MICs), measurement of minimum bactericidal concentrations (MBCs) and the ability of the steroid derivatives to lower the MICs of other antibiotics, e.g., erythromycin and novobiocin. A person of skill will recognize that the compounds described herein preserve certain stereochemical and electronic characteristics found in steroids. The term “same configuration” as used herein refers to substituents on the fused steroid having the same stereochemical orientation. For example substituents R3, R7 and R12 are all β-substituted or α-substituted. The configuration of the moieties R3, R7, and R12 substituted on C3, C7, and C12 may be important for interaction with the cellular membrane. In another aspect, the invention features several methods of using the above-described compounds. For example, an effective amount of an anti-microbial composition comprising such a compound is administered to a host (including a human host) to treat a microbial infection. The compound by itself may provide the anti-microbial effect, in which case the amount of the compound administered is sufficient to be anti-microbial. Alternatively, an additional anti-microbial substance to be delivered to the microbial cells (e.g., an antibiotic) is included in the anti-microbial composition. By facilitating delivery to the target cells, the compounds can enhance the effectiveness of the additional antimicrobial substance. In some cases the enhancement may be substantial. Particularly important target microbes are bacteria (e.g., Gram-negative bacteria generally or bacteria which have a substantial (>40%) amount of a lipid A or lipid A-like substance in the outer membrane). Other microbes including fungi, viruses, and yeast may also be the target organisms. The compounds can also be administered in other contexts to enhance cell permeability to introduce any of a large number of different kinds of substances into a cell, particularly the bacterial cells discussed above. In addition to introducing anti-microbial substances, the invention may be used to introduce other substances such as macromolecules (e.g., vector-less DNA). The invention can also be used to make anti-microbial compositions (e.g., disinfectants, antiseptics, antibiotics etc.) which comprise one of the above compounds. These compositions are not limited to pharmaceuticals, and they may be used topically or in non-therapeutic contexts to control microbial (particularly bacterial) growth. For example, they may be used in applications that kill or control microbes on contact. In yet another aspect, the invention generally features methods of identifying compounds that are effective against a microbe by administering a candidate compound and a compound according to the invention the microbe and determining whether the candidate compound has a static or toxic effect (e.g, an antiseptic, germicidal, disinfectant, or antibiotic effect) on the microbe. Again, bacteria such as those discussed above are preferred. This aspect of the invention permits useful testing of an extremely broad range of candidate anti-microbials which are known to have anti-microbial effect in some contexts, but which have not yet been shown to have any effect against certain classes of microbes such as the bacteria discussed above. As described in greater detail below, this aspect of the invention permits testing of a broad range of antibiotics currently thought to be ineffective against Gram-negative or lipid A-like containing bacteria. In yet another aspect the invention features compositions which include one of the above compounds in combination with a substance to be introduced into a cell such as an antimicrobial substance as described in greater detail above. The compound and the additional substance may be mixed with a pharmaceutically acceptable carrier. Other features or advantages of the present invention will be apparent from the following detailed description of several embodiments, and also from the appending claims. The invention encompasses steroid derivatives that can be made by the synthetic routes described herein, and methods of treating a subject having a condition mediated by a bacterial infection by administering an effective amount of a pharmaceutical composition containing a compound disclosed herein to the subject. | 20040716 | 20091006 | 20050210 | 72050.0 | 1 | BADIO, BARBARA P | STEROID DERIVED ANTIBIOTICS | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,893,790 | ACCEPTED | Liquid crystal display device and method of fabricating the same | When radiating light onto a liquid crystal composition containing a photosensitive material, the alignment of liquid crystal molecules is adjusted by applying a voltage to the liquid crystal composition layer, to achieve substantially orderly alignment of the liquid crystal molecules, or the alignment of the liquid crystal molecules is made uniform by adjusting the structure of the liquid crystal display device, or any display defect is driven out of the display area. When radiating light to the liquid crystal composition containing the photosensitive material, the alignment of the liquid crystal molecules can be adjusted so as to achieve substantially orderly alignment of the liquid crystal molecules, and the liquid crystal display device can thus be driven stably. | 1. A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light to the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying AC voltages to the common electrode and the Cs bus line. 2. A method of fabricating a liquid crystal display device as described in claim 1, wherein the common electrode and the Cs bus line are insulated from each other or connected via high resistance when radiating the light to the liquid crystal layer. 3. A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connected to the thin-film transistor, and a Cs bus line that forms an electrical capacitance with the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; insulating the common electrode from the three bus lines, or connecting the common electrode to the three bus lines via high resistance; and radiating light onto the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the three bus lines (the gate bus line, the data bus line, and the Cs bus line) formed on the second substrate. 4. A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with at least one of the data bus and gate bus lines; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light onto the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the four bus lines (the gate bus line, the data bus line, the Cs bus line, and the repair line) formed on the second substrate. 5. A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and connecting the common electrode via high resistance to the three bus lines (the gate bus line, the data bus line, and the Cs bus line,) formed on the second substrate, and radiating light onto the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and at least one of the bus lines. 6. A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; electrically connecting adjacent data bus lines at both ends thereof; and radiating light onto the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line. 7. A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with the data bus line; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; connecting at least one data bus line with at least one repair line by laser radiation or another method; and radiating light onto the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line and repair line (the repair line is at the same potential as the data bus line). 8. A method of fabricating a vertical alignment liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition into a gap between two substrates each having a transparent electrode and an alignment control film for causing liquid crystal molecules to align vertically, the liquid crystal composition having a negative dielectric anisotropy and containing a polymerizable monomer; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to the liquid crystal molecules, and wherein: before polymerizing the monomer, a constant voltage not smaller than a threshold voltage but not greater than a saturation voltage is applied between the opposing transparent electrodes for a predetermined period of time, and thereafter, the voltage is changed to a prescribed voltage and, while maintaining the prescribed voltage, ultraviolet radiation or heat is applied to the liquid crystal composition to polymerize the monomer. 9. A method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between two substrates each having a transparent electrode; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to liquid crystal molecules while, at the same time, controlling the direction in which the liquid crystal molecules tilt in the presence of an applied voltage, and wherein: light radiation for polymerizing the polymerizable monomer is performed in at least two steps. 10. A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a plurality of injection ports for injecting therethrough the liquid crystal composition containing the polymerizable component are formed in one side of the liquid crystal display device, and the spacing between the respective injection ports is not larger than one-fifth of the length of the side in which the injection ports are formed. 11. A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein the cell gap in a frame edge BM area is not larger than the cell gap of a display area. 12. A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a main seal or an auxiliary seal is formed in a frame edge BM area to eliminate the cell gap in the frame edge BM area. 13. A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein an auxiliary seal is formed so that a material, whose concentration of the polymerizable material relative to liquid crystal is abnormal, is guided into a BM area. 14. A method of fabricating a liquid crystal display device, comprising: forming a common electrode and a color filter layer on a first substrate; constructing a second substrate from an array substrate on which are formed a gate bus line layer, a gate insulating film layer, a drain bus line layer, a protective film layer, and a pixel electrode layer; forming fine slits in the pixel electrode layer in such a direction that a pixel is divided by the slits into at least two sub-regions; forming on each of the two substrates a vertical alignment film for vertically aligning liquid crystal molecules; forming a liquid crystal layer by filling an n-type liquid crystal composition having a negative dielectric anisotropy into a gap between the two substrates, the liquid crystal composition containing an ultraviolet curable resin having a liquid crystal backbone; radiating ultraviolet light while applying to the liquid crystal molecules a voltage not smaller than a threshold value of the liquid crystal molecules, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage; and arranging two polarizers on top and bottom surfaces of the liquid crystal display device in a crossed Nicol configuration with the absorption axes thereof oriented at an angle of 45 degrees to the alignment directions of the liquid crystal molecules. 15. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein any portion where the cell thickness varies by 10% or more due to design constraints is located at a liquid crystal domain boundary. 16. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a source electrode and a pixel electrode is formed at a liquid crystal domain boundary. 17. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a Cs intermediate electrode and a pixel electrode is formed at a liquid crystal domain boundary. 18. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one portion where cell thickness varies by 10% or more due to design constraints does not exist. 19. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one contact hole is not formed in the same sub-region. 20. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a pixel electrode, a source electrode, and a Cs intermediate electrode are connected by a single contact hole. 21. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a metal electrode is added along a liquid crystal domain boundary within a display pixel. 22. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein an electrode having the same potential as a pixel electrode is not added to a slit portion of the pixel electrode within a display pixel. 23. A method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between a pair of substrates having electrodes; and polymerizing the monomer by radiating ultraviolet light to the liquid crystal composition while applying a prescribed liquid crystal driving voltage between opposing electrodes, and wherein: after polymerizing the monomer, additional ultraviolet radiation is applied to the liquid crystal composition without applying the liquid crystal driving voltage or while applying a voltage of a magnitude that does not substantially drive the liquid crystal. | CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 107,989, filed Mar. 27, 2002, now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device to be used for television and other display apparatuses, to a method of fabricating the same and, more particularly, to a liquid crystal display device that uses a liquid crystal material containing a photosensitive material and a method of fabricating the same. 2. Description of the Related Art A liquid crystal display device is a display device that comprises a liquid crystal sealed between two opposing substrates and that uses electrical stimulus for optical switching by exploiting the electro-optical anisotropy of a liquid crystal. Utilizing the refractive index anisotropy that the liquid crystal possesses, the brightness of the light transmitted by the liquid crystal panel is controlled by applying a voltage to the liquid crystal and thereby reorienting the axis of the refractive index anisotropy. In such a liquid crystal display device, it is extremely important to control the alignment of liquid crystal molecules when no voltage is applied to the liquid crystal. If the initial alignment is not stable, when a voltage is applied to the liquid crystal, the liquid crystal molecules do not align in a predictable manner, resulting in an inability to control the refractive index. Various techniques have been developed to control the alignment of liquid crystal molecules, representative examples including a technique that controls the initially formed angle (pretilt angle) between the alignment film and the liquid crystal and a technique that controls the horizontal electric field formed between the bus line and the pixel electrode. The same can be said of a display device that uses a liquid crystal material containing a photosensitive material; specifically, in a liquid crystal display mode in which the initial alignment is controlled by radiation of light in the presence of an applied voltage, the voltage application method during the radiation becomes important. The reason is that, if the magnitude of the applied voltage differs, a change will occur in the initially formed pretilt angle, resulting in a change in transmittance characteristics. In connection with a first aspect of the invention, techniques called passive matrix driving and active matrix driving have usually been used to drive liquid crystals; nowadays, with an increasing demand for higher resolution, the active matrix display mode that uses thin-film transistors (TFTs) is the dominant liquid crystal display mode. In a liquid crystal display having such TFTs, when radiating light onto the liquid crystal while applying a voltage to it, it is usually practiced to expose the liquid crystal to light radiation while applying a TFT ON voltage to each gate bus line and a desired voltage to each data bus line, as shown in FIGS. 1 and 2. However, when such a liquid crystal exposure method is employed, if there is a line defect due to a bus line break or short, as shown in FIG. 3, the liquid crystal will be exposed to light when the liquid crystal in the affected area cannot be driven, and a pretilt angle different from that in other areas will be formed in this defect area, resulting in the problem that the brightness in this area differs from the brightness in other areas. Or, in the TFT channel ON state, a shift in the TFT threshold value can occur due to exposure to ultraviolet radiation, as shown in FIG. 4, resulting in the problem that the region where the TFTs can be driven stably shifts from the desired region. On the other hand, in connection with a second aspect of the invention, displays using the TN mode have been the predominant type of active matrix liquid crystal display, but this type of display has had the shortcoming that the viewing angle is narrow. Nowadays, a technique called the MVA mode or a technique called the IPS mode is employed to achieve a wide viewing angle liquid crystal panel. In the IPS mode, liquid crystal molecules are switched in the horizontal plane by using comb-shaped electrodes, but a strong backlight is required because the comb-shaped electrodes significantly reduce the molecules are aligned vertically to the substrates, and the alignment of the liquid crystal molecules is controlled by the use of protrusions or slits formed in a transparent electrode (for example, an ITO electrode). The decrease in the effective numerical aperture due to the protrusions or slits used in MVA is not so large as that caused by the comb-electrodes in IPS, but compared with TN mode displays, the light transmittance of the liquid crystal panel is low, and it has not been possible to employ MVA for notebook computers that require low power consumption. When fine slits are formed in the ITO electrode, the liquid crystal molecules tilt parallel to the fine slits, but in two different directions. If the fine slits are sufficiently long, liquid crystal molecules located farther from a structure such as a bank that defines the direction in which the liquid crystal molecules tilt are caused to tilt randomly in two directions upon application of a voltage. However, the liquid crystal molecules located at the boundary between the liquid crystal molecules caused to tilt in different directions, cannot tilt in either direction, resulting in the formation of a dark area such as that shown in FIG. 29. Further, in a structure where the liquid crystal molecules are caused to tilt in two different directions in order to improve viewing angle, if there are liquid crystal molecules that are caused to tilt in the opposite direction, as shown in FIG. 29, the viewing angle characteristics degrade. In connection with a third aspect of the invention, in an LCD (MVA-LCD) in which an N-type liquid crystal is aligned vertically and in which, upon application of a voltage, the molecules of the liquid crystal are caused to tilt in a number of predefined directions by using alignment protrusions or electrode slits, the liquid crystal molecules are almost completely vertically aligned in the absence of an applied voltage, but are caused to tilt in the various predefined directions when a voltage is applied. The tilt directions of the liquid crystal molecules are controlled so that they always make an angle of 45° to the polarizer absorption axis, but the liquid crystal molecules as a continuum can tilt in a direction intermediate between them. Furthermore, areas where the tilt direction of the liquid crystal molecules is displaced from the predefined direction inevitably exist because of the effects of the horizontal electric field, etc. at the time of driving or irregularities in the structure. In normally black displays where the polarizers are arranged in a crossed Nicol configuration, this means that dark areas appear when the display is driven in the white display state, and the screen brightness thus decreases. To address this problem, in a liquid crystal display device constructed by sandwiching between two substrates a liquid crystal composition containing a photopolymerizable or thermally polymerizable component, there is employed a technique that polymerizes the polymerizable component while applying a voltage, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage. With this technique, however, if the polymerization is insufficient, image sticking can occur. This is believed to occur because the rigidity of the polymerized polymer is insufficient and deformation occurs due to the realignment of the liquid crystal molecules at the time of voltage application. On the other hand, to sufficiently polymerize the polymer, the duration of light radiation must be increased, but in that case, takt time at the time of volume production becomes a problem. In connection with a fourth aspect of the invention, conventional liquid crystal display devices predominantly use the TN mode in which horizontally aligned liquid crystal molecules are twisted between the top and bottom substrates, but gray-scale inversion occurs in the mid gray-scale range because the tilt angle of the liquid crystal differs depending on the viewing direction, that is, the viewing angle. To address this, a technique called the MVA mode has been proposed in which vertically aligned liquid crystal molecules are tilted symmetrically in opposite directions to compensate for the viewing angle. In this technique, alignment control members made of an insulating material are formed on electrodes to control the liquid crystal tilt directions. However, since the liquid crystal molecules tilt in 180° opposite directions on both sides of each alignment control member, a dark line is formed and transmittance decreases. To obtain sufficient transmittance, it is preferable to reduce the area occupied by the alignment control members by forming them spaced farther apart, but this would in turn slow the propagation speed of the tilt, resulting in a slow response speed. To address this, a technique has been proposed in which a liquid crystal composition containing a polymerizable component is sandwiched between substrates and, while applying a voltage, the polymerizable component is polymerized, thereby defining the tilt direction of the liquid crystal molecules. This achieves a faster response speed while retaining the transmittance. However, in the case of a liquid crystal display device in which the tilt direction of the liquid crystal molecules is defined by polymerizing the polymerizable component in the liquid crystal while applying a voltage, there arises the problem that display unevenness occurs after the polymerization of the polymerizable component, because of the separation of the liquid crystal and the polymerizable component which occurs when the liquid crystal material is injected at high speed at the initial stage of injection or when there is an abrupt change in speed near a frame edge. In connection with a fifth aspect of the invention, in a liquid crystal display device, it has traditionally been practiced to control the alignment direction of the vertically aligned panel by a TFT substrate having slits in pixel electrodes and a color filter substrate having insulating protrusions, and it has therefore been necessary to form the dielectric protrusions on one of the substrates. Fabrication of such a liquid crystal display device therefore has involved the problem that the number of processing steps increases. Furthermore, forming the protrusions within display pixels leads to the problem that the numerical aperture decreases, reducing the transmittance. In view of this, it has been proposed to control the alignment of the liquid crystal molecules by a polymerizable component added in the liquid crystal, in order to achieve multi-domains without using dielectric layer protrusions. That is, the liquid crystal to which the polymerizable component is added is injected into the panel and, while applying a voltage, the polymerizable component is polymerized, thereby controlling the alignment of the liquid crystal molecules. However, if the polymer composition that defines the alignment direction does not have a sufficient cross-linked structure, the polymer becomes flexible, and its restoring force weakens. If the polymer has such properties, then, when a voltage is applied to the liquid crystal to cause the liquid crystal molecules to tilt, and the liquid crystal is still held in that state, the pretilt angle of the liquid crystal does not return to its initial state even after the applied voltage is removed. This means that the voltage-transmittance characteristic has changed, and this defect manifests itself as a pattern image sticking. In connection with a sixth aspect of the invention, in an MVA-LCD in which liquid crystals having a negative dielectric anisotropy are vertically aligned, and in which the alignment of the liquid crystal in the presence of an applied voltage is controlled in a number of predefined directions, without using a rubbing treatment but by utilizing the banks or slits formed on the substrates, the LCD provides excellent viewing angle characteristics compared with conventional TN mode LCDs, but there is a disadvantage that white brightness is low and the display is therefore relatively dark. The major reason is that portions above the banks or slits correspond to the boundaries across which the liquid crystal alignment changes, and these portions appear optically dark, reducing the transmittance of white. To improve this, the spacing between the banks or slits should be made sufficiently wide, but in that case, as the number of banks or slits for controlling the liquid crystal alignment decreases, it takes time until the alignment stabilizes, thus slowing the response speed. To obtain a brighter, faster response MVA panel by alleviating the above deficiency, it is effective to use a technique in which a liquid crystal composition containing a polymerizable component is sandwiched between substrates and, while applying a voltage, the polymerizable component is polymerized, thereby defining the tilt direction of the liquid crystal molecules. For the polymerizable component, a monomer material that polymerizes by ultraviolet radiation or heat is usually used. It has, however, been found that this method has a number of problems associated with display unevenness. That is, as this method is a rubbing-less method, if there occurs even a slight change in the structure or in electric lines of force, the liquid crystal molecules may not align in the desired direction. As a result, there are cases where a contact hole or the like formed outside the display area disrupts the alignment of the liquid crystal molecules and the disruption affects the alignment of the liquid crystal molecules within the display area, resulting in the formation of an abnormal domain and causing the alignment to be held in that state. Furthermore, if structures that cause such disruptions in liquid crystal molecular alignment are located in the same alignment sub-region, abnormal domains formed from the respective structures are concatenated, forming a larger abnormal domain. This causes the liquid crystal molecules outside and inside the display area to be aligned in directions other than the desired directions, and the polymerizable component is polymerized in that state, resulting in such problems as reduced brightness, slower response speed, and display unevenness. FIG. 44 is a plan view showing a pixel in the prior art. In the pixel shown here, contact holes that cause variations in cell thickness are not located at liquid crystal domain boundaries, and two contact holes are located within the same alignment sub-region. As a result, an abnormal domain is formed in such a manner as to connect the two contact holes and, with the alignment held in this state, the polymerizable component is polymerized, resulting in display performance degradations such as reduced brightness, slower response speed, and display unevenness. Further, when a metal electrode such as a source electrode or a Cs intermediate electrode is extended into the display pixel, there occurs the problem of reduced numerical aperture, and hence, reduced brightness. Moreover, if an electrode with the same potential as the pixel electrode is extended into the display pixel, this also causes reduced brightness, slower response speed, and display unevenness. In connection with a seventh aspect of the invention, while conducting studies on the technique in which a liquid crystal composition containing a polymerizable component is sandwiched between substrates and, while applying a voltage, the polymerizable component is polymerized, thereby defining the tilt direction of the liquid crystal molecules, the inventor et al. encountered the problem that when the same pattern was displayed for a certain length of time, image sticking occurred in the portion where the pattern was displayed. This is believed to occur because the polymerization is insufficient and the polymer deforms. On the other hand, to sufficiently polymerize the polymer, the duration of light radiation or heating must be increased, but in that case, tact time at the time of volume production becomes a problem. BRIEF SUMMARY OF THE INVENTION The present invention aims to solve the above-enumerated problems of the prior art and to provide a method of fabricating a liquid crystal display device which, during fabrication of the liquid crystal display device, controls the alignment of liquid crystal molecules when radiating light onto a liquid crystal composition containing a photosensitive material, and thereby achieves substantially uniform alignment of the liquid crystal molecules and ensures stable operation. The invention also aims to provide such a liquid crystal display device. To solve the above-enumerated problems, the first aspect of the invention provides methods based on the following three major concepts. 1. Avoid the effects of wiring defects by driving the liquid crystal by applying an AC voltage and using an electrical capacitance. 2. Avoid the effects of wiring defects by holding the wiring lines and electrodes on the second substrate at the same potential. 3. Avoid the effects of wiring defects while screening TFT channel portions from light. More specifically, based on the first concept, the first aspect of the invention provides (1) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light to the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying AC voltages to the common electrode and the Cs bus line. Based on the second concept, the invention provides (2) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; insulating the common electrode from the three bus lines, or connecting the common electrode to the three bus lines via high resistance; and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the three bus lines (the gate bus line, the data bus line, and the Cs bus line) formed on the second substrate, or (3) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with at least one of the data bus and gate bus lines; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the four bus lines (the gate bus line, the data bus line, the Cs bus line, and the repair line) formed on the second substrate, or (4) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and connecting the common electrode, via high resistances, to the three bus lines (the gate bus line, the data bus line, and the Cs bus line,) formed on the second substrate, and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and at least one of the bus lines. Based on the third concept, the invention provides (5) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; electrically connecting adjacent data bus lines at both ends thereof; and radiating light to the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line, or (6) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with the data bus line; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; connecting at least one data bus line with at least one repair line by laser radiation or another method; and radiating light to the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line and repair line (the repair line is at the same potential as the data bus line). In the second aspect of the invention, there is provided (7) a method of fabricating a vertical alignment liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition into a gap between two substrates each having a transparent electrode and an alignment control film for causing liquid crystal molecules to align vertically, the liquid crystal composition having a negative dielectric anisotropy and containing a polymerizable monomer; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to the liquid crystal molecules, and wherein: before polymerizing the monomer, a constant voltage not smaller than a threshold voltage but not greater than a saturation voltage is applied between the opposing transparent electrodes for a predetermined period of time, and thereafter, the voltage is changed to a prescribed voltage and, while maintaining the prescribed voltage, ultraviolet radiation or heat is applied to the liquid crystal composition to polymerize the monomer. That is, when polymerizing the polymerizable monomer, a voltage slightly higher than the threshold voltage is applied and, after the liquid crystal molecules are tilted in the right direction, the voltage is raised to a higher level; then, while maintaining the voltage at the higher level, the polymerizable monomer is polymerized. In the third aspect of the invention, there is provided (8) a method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between two substrates each having a transparent electrode; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to liquid crystal molecules while, at the same time, controlling the direction in which the liquid crystal molecules tilt in the presence of an applied voltage, and wherein: light radiation for polymerizing the polymerizable monomer is performed in at least two steps. In the fourth aspect of the invention, there is provided (9) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is photopolymerized or thermally polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a plurality of injection ports for injecting therethrough the liquid crystal composition containing the polymerizable component are formed in one side of the liquid crystal display device, and spacing between the respective injection ports is not larger than one-fifth of the length of the side in which the injection ports are formed, or (10) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a cell gap in a frame edge BM area is not larger than the cell gap of a display area, or (11) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a main seal or an auxiliary seal is formed in a frame edge BM area to eliminate a cell gap in the frame edge BM area, or (12) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein an auxiliary seal is formed so that a material whose concentration of the polymerizable material relative to liquid crystal is abnormal is guided into a BM area. In the fifth aspect of the invention, there is provided (13) a method of fabricating a liquid crystal display device, comprising: forming a common electrode and a color filter layer on a first substrate; constructing a second substrate from an array substrate on which are formed a gate bus line layer, a gate insulating film layer, a drain bus line layer, a protective film layer, and a pixel electrode layer; forming fine slits in the pixel electrode layer in such a direction that a pixel is divided by the slits into at least two sub-regions; forming on each of the two substrates a vertical. alignment film for vertically aligning liquid crystal molecules; forming a liquid crystal layer by filling an n-type liquid crystal composition having a negative dielectric anisotropy into a gap between the two substrates, the liquid crystal composition containing an ultraviolet curable resin having a liquid crystal backbone; radiating ultraviolet light while applying to the liquid crystal molecules a voltage not smaller than a threshold value of the liquid crystal molecules, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage; and arranging two polarizers on top and bottom surfaces of the liquid crystal display device in a crossed Nicol configuration with the absorption axes thereof oriented at an angle of 45 degrees to the alignment directions of the liquid crystal molecules. In the sixth aspect of the invention, there is provided (14) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein any portion where cell thickness varies by 10% or more due to design constraints is located at a liquid crystal domain boundary, or (15) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a source electrode and a pixel electrode is formed at a liquid crystal domain boundary, or (16) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a Cs intermediate electrode and a pixel electrode is formed at a liquid crystal domain boundary, or (17) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one portion where cell thickness varies by 10% or more due to design constraints does not exist, or (18) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one contact hole is not formed in the same sub-region, or (19) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a pixel electrode, a source electrode, and a Cs intermediate electrode are connected by a single contact hole, or (20) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a metal electrode is wired along a liquid crystal domain boundary within a display pixel, or (21) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein an electrode having the same potential as a pixel electrode is not wired in a slit portion of the pixel electrode within a display pixel. In the seventh aspect of the invention, there is provided a (22) a method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between a pair of substrates having electrodes; and polymerizing the monomer by radiating ultraviolet light to the liquid crystal composition while applying a prescribed liquid crystal driving voltage between opposing electrodes, and wherein: after polymerizing the monomer, additional ultraviolet radiation is applied to the liquid crystal composition without applying the liquid crystal driving voltage or while applying a voltage of a magnitude that does not substantially drive the liquid crystal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view showing one example of a liquid crystal display device fabricated according to the prior art. FIG. 2 is a schematic cross-sectional view of the liquid crystal display device of FIG. 1. FIG. 3 is a schematic plan view showing one example of the liquid crystal display device fabricated according to the prior art. FIG. 4 is a graph showing one example of a TFT threshold value shift as observed in the liquid crystal display device fabricated according to the prior art. FIG. 5 is a schematic plan view showing one example of electrical coupling in a prior art TFT liquid crystal panel. FIG. 6 is a schematic plan view showing another example of electrical coupling in a prior art TFT liquid crystal panel. FIG. 7 is a schematic plan view for explaining one example of a fabrication method for a liquid crystal display device according to the present invention. FIG. 8 is a schematic plan view for explaining one example of a fabrication method for a liquid crystal display device according to the present invention. FIG. 9 is a schematic plan view showing a liquid crystal display device according to a first embodiment. FIG. 10 is a graph showing the display characteristics of the liquid crystal display device according to the first embodiment. FIG. 11 is a graph showing the display characteristics of the liquid crystal display device according to the first embodiment. FIG. 12 is a schematic plan view showing a liquid crystal display device according to a second embodiment. FIG. 13 is a diagram for explaining one method used in a third embodiment to short a Cs bus line to a common electrode. FIG. 14 is a diagram for explaining another method used in the third embodiment to short the Cs bus line to the common electrode. FIG. 15 is a schematic plan view showing a liquid crystal display device according to a fourth embodiment. FIG. 16 is a graph showing results in a sixth embodiment. FIG. 17 is a schematic plan view showing a liquid crystal display device according to a seventh embodiment. FIG. 18 is a schematic plan view showing a liquid crystal display device according to an eighth embodiment. FIG. 19 is a schematic plan view showing a liquid crystal display device according to a ninth embodiment. FIG. 20 is a schematic plan view showing another example of the liquid crystal display device according to the ninth embodiment. FIG. 21 is a schematic plan view showing another example of the liquid crystal display device according to the ninth embodiment. FIG. 22 is a schematic plan view showing a liquid crystal display device according to a 10th embodiment. FIG. 23 is a schematic cross-sectional view showing a liquid crystal display device according to an 11th embodiment. FIG. 24 is a schematic plan view showing a liquid crystal display device according to a 12th embodiment. FIG. 25 is a schematic plan view of a liquid crystal panel fabricated according to a 13th embodiment. FIG. 26 is a schematic cross-sectional view showing one example of the liquid crystal panel of FIG. 25. FIG. 27 is a schematic cross-sectional view showing another example of the liquid crystal panel of FIG. 25. FIG. 28 is a schematic plan view of a liquid crystal panel fabricated according to a 14th embodiment. FIG. 29 is a schematic plan view for explaining a prior art example. FIG. 30 is a schematic plan view for explaining a prior art example. FIG. 31 is a schematic cross-sectional view showing the liquid crystal panel of FIG. 30. FIG. 32 is a schematic diagram for explaining a prior art example. FIG. 33 is a schematic diagram showing UV radiation methods used in first and second comparative examples and 15th to 17th embodiments. FIG. 34 is a schematic plan view showing a liquid crystal panel according to an 18th embodiment. FIG. 35 is a schematic cross-sectional view showing a liquid crystal panel according to a 19th embodiment. FIG. 36 is a schematic cross-sectional view showing a liquid crystal panel according to a 20th embodiment. FIG. 37 is a schematic plan view showing a liquid crystal panel according to a 21st embodiment. FIG. 38 is a schematic cross-sectional view showing a liquid crystal panel according to a 22nd embodiment. FIG. 39 is a schematic plan view of the liquid crystal panel according to the 22nd embodiment. FIG. 40 is a schematic diagram for explaining how the alignments of liquid crystal molecules are controlled in the 22nd embodiment. FIG. 41 is a process flow diagram of the 22nd embodiment. FIG. 42 is a schematic diagram showing equipment used in a 23rd embodiment. FIG. 43 is a schematic cross-sectional view showing a liquid crystal panel according to a 24th embodiment. FIG. 44 is a plan view showing a pixel in a prior art liquid crystal display device. FIG. 45 is a diagram showing a plan view and a cross-sectional view of a pixel in a liquid crystal display device according to a 25th embodiment. FIG. 46 is a diagram showing a plan view of a pixel in a liquid crystal display device according to a 26th embodiment. FIG. 47 is a diagram showing a plan view of a pixel in a liquid crystal display device according to a 27th embodiment. FIG. 48 is a diagram showing a plan view and a cross-sectional view of a pixel in a liquid crystal display device according to a 28th embodiment. FIG. 49 is a schematic diagram showing a plan view and a side view illustrating a method of additional ultraviolet radiation according to a 29th embodiment. FIG. 50 is a graph showing the relationship between the amount of additional ultraviolet radiation and the image sticking ratio according to the 29th embodiment. DETAILED DESCRIPTION OF THE INVENTION The first aspect of the invention discloses the following methods as specific implementations thereof. 1) The method described in above item (1), wherein the common electrode and the Cs bus line are insulated from each other or connected via high resistance when radiating the light to the liquid crystal layer. 2) The method described in above item (1), wherein after radiating the light to the liquid crystal layer, the common electrode and the Cs bus line are electrically connected together. 3) The method described in above item (1), wherein a transistor OFF voltage is applied to the gate bus line. 4) The method described in above item (1), wherein initially the liquid crystal layer is vertically aligned and, by radiating the light while applying a voltage to the liquid crystal composition containing the photosensitive material, the average angle of the liquid crystal to an alignment film is set smaller than a polar angle of 90°. 5) The method described in above item (1), wherein the AC frequency, when applying the AC voltage, is set within a range of 1 to 1000 Hz. 6) The method described in above item (2), wherein adjacent gate bus lines or data bus lines are electrically connected together at both ends thereof. 7) The method described in above item (2), wherein after radiating the light to the liquid crystal layer, the common electrode and the Cs bus line are electrically connected together. 8) The method described in above item (2), wherein initially the liquid crystal layer is vertically aligned and, by radiating light while applying a voltage to the liquid crystal composition containing the photosensitive material, the average angle of the liquid crystal to the alignment film is set smaller than a polar angle of 90°. Usually, a TFT liquid crystal panel has electrical couplings such as shown in FIG. 5. At this time, the two electrodes, that is, the common electrode and the pixel electrode, form an electrical capacitance Clc by holding therebetween such materials as the liquid crystal and alignment film. The Cs bus line in the figure forms an electrical capacitance Cs between it and each pixel electrode, and controls the amount of voltage fluctuation and the amount of charge to be written to the pixel electrode. Usually, the writing of a charge to the pixel electrode is done via a thin-film transistor (TFT), and to achieve this, the gate bus line that acts as a switch for writing and the data bus line used to write a voltage to the pixel electrode are arranged in a matrix form in such a manner as to sandwich the pixel electrode between them. Fatal pattern defects (wiring defects) that can occur in the TFT liquid crystal panel include: a. Gate bus line breakage b. Data bus line breakage c. Cs bus line breakage d. Intra-layer short between gate bus line and Cs bus line e. Interlayer short between gate bus line and data bus line f. Interlayer short between Cs bus line and data bus line These defects decrease fabrication yields. To counter these defects, redundant design techniques are employed, and repairs are frequently done not only immediately after the formation of the pattern but also after the cell is completed by injecting the liquid crystal. Since the defects a, c, and d are defects introduced in the first layer formed on the substrate, rework is easy, and usually they are not defects that require reworking after the cell has been completed. In particular, for the defect c, since the Cs bus line is a common electrode, it is easy to form a redundant pattern, for example, by bundling the lines at both ends of the LCD panel, as shown in FIG. 6, and if the electrical conductivity of the film is higher than a certain value, this defect can be avoided. On the other hand, the defects b, e, and f are defects that often require reworking after the cell has been completed and, when radiating light to the liquid crystal, the liquid crystal cannot be driven normally by applying a write voltage via the data bus line. In view of this, in the method of the invention based on the first concept, writing is performed by applying a voltage between the two common electrodes, rather than applying a write voltage to the liquid crystal via the data bus line. The above-described problem that arises when writing via the data bus line can then be ignored to some degree. The reason is that, as the pixel electrode is treated as a floating layer, it is unaffected by such defects as b and e. This is because the application of an AC voltage between the common electrode and the Cs bus line results in the formation of a circuit that applies an AC voltage across a series coupling where pixel potential is approximately Cls and Cs, the applied voltage to the liquid crystal part being given by Applied voltage to liquid crystal part=Zlc/(Zlc+Zc)×AC voltage where Zlc and Zc are the respective impedances. At this time, if the gate bus line voltage is floating, the TFT is substantially OFF, and avoidance of the threshold value shift, another object of the invention, is automatically achieved. In practice, it is also possible to actively apply an OFF voltage to the gate bus line; in this case, the electrical capacitance Cgc that the gate bus line and the common electrode form and the capacitance Cgs that the gate bus line and the pixel electrode form affect the value of the applied voltage to the liquid crystal part. The method of the invention based on the second concept proposes to avoid the defects b, e, and f by applying a DC voltage and holding the wiring lines and electrodes on the second substrate at the same potential as specified in the present invention. For the defects e and f, in theory, a condition in which the short is completely invisible can be achieved if voltages on the data bus line, the Cs bus line, and the gate bus line are all the same. Of course, this is intended to be achieved only during exposure to light. For example, when a DC voltage of 0 V is applied to the common electrode and a DC voltage of 5 V to the data bus line, the Cs bus line, and the gate bus line, it follows that 5 V is applied to the pixel electrode. That is, though the data bus line and the pixel electrode are connected via the TFT, the charge gradually flows into the pixel electrode which is thus charged up to 5 V after a sufficient time. This means that the condition of common electrode (0 V)−pixel electrode (5 V) is achieved, and the voltage can thus be applied to the liquid crystal. Since liquid crystals used for TFT displays usually have high resistance, movement of ions in the liquid crystal layer can virtually be neglected. According to the above concept, means for avoiding the defect b can also be obtained. That is, usually an ESD circuit (Electrostatic Discharge circuit) is formed in a TFT panel for protection against electrostatic discharge, as shown in FIG. 6. This is equivalent to achieving a condition in which the respective bus lines are connected via high resistance. As in the case of FIG. 6, even when there is a break in a data bus line, if there is any voltage input path on the opposite side, the desire voltage for application can be obtained after a sufficient time even if the connection is made by high resistance. The method of the invention based on the third concept is aimed at radiating light to the liquid crystal by avoiding a wiring defect while directly preventing UV radiation to TFT channel portions. In this case, normal driving is possible when applying a voltage to the liquid crystal. This method, however, proposes to apply a voltage to the bus line from both ends thereof in order to avoid the effects of a line defect. This makes it possible to avoid the effects of the defect b. With advances in inspection techniques in recent years, it has become possible to detect defect coordinates with high accuracy before the cell is completed. If only defect coordinates can be confirmed, then a defect of type e or f can be converted to a defect of type b by the processing such as shown in FIG. 7. If this repair can be done before radiating light onto the liquid crystal, the effects of a line defect can be avoided by combining this technique with the method proposed here. The method of the invention can also be applied to the following cases. First, the method can be applied to the TFT design called the Cs-on-gate type, as shown in FIG. 8. Though the structure shown does not have Cs bus lines, the method of the invention based on the second or third concept can likewise be applied to this type of design. In the case of the method of the invention based on the first concept, when the capacitances formed by the pixel electrode and the respective gate bus lines are denoted by Cgs1 and Cgs2, it is expected that the applied voltage to the liquid crystal part is substantially determined by Applied voltage to the liquid crystal part=Zlc/(Zlc+Zgs)×AC voltage where Zgs is the impedance. Second, the method can be applied to the fabrication process of a liquid crystal display device in which a uniform DC voltage is applied to the liquid crystal during the fabrication thereof. For example, when determining the initial alignment of a ferroelectric liquid crystal, there are cases where it is required to apply a DC voltage uniformly over the entire surface; in such cases also, line defects may become a problem as in the case of the method of the present invention. Third, the method can be applied to the case where the IPS mode is combined with a photosensitive material. In the case of IPS, the direction of the electric field formed at the time of exposure is assumed not only between the top and bottom substrates but also between the comb-shaped electrodes. Though the method of the invention assumes that the common electrode is formed on the first substrate, the method can also be applied to the case where a voltage is applied between the pixel electrode and the common electrode on the second substrate. In the liquid crystal display device fabricated according to the method of the present invention, generally, the spacing between the first and second substrates is maintained constant by means of a structure supporting them or by means of gap support members such as plastic beads as shown in FIG. 2, and the liquid crystal material held between the two substrates is sealed into the gap between them by fixing its periphery with an adhesive layer. The second aspect of the invention discloses the following methods as specific implementations thereof. 1) The method described in above item (7) wherein, after a constant voltage not smaller than the threshold voltage but not greater than the threshold voltage+1 V is applied between the opposing transparent electrodes for a time not shorter than 10 seconds, the voltage is changed by applying a voltage not smaller than a voltage to be applied to produce a white display state and, while maintaining the voltage, the ultraviolet radiation or heat is applied to the liquid crystal composition to polymerize the monomer. 2) The method described in above item (7), wherein the transparent electrode on at least one of the substrates has a 0.5- to 5-micron fine slit structure. 3) The method described in above item (7), wherein the fine slit structure is formed from fine ITO slits formed in vertical direction. 4) The method described in above item (7), wherein the length of each of the fine ITO slits is approximately one half the vertical length of the pixel electrode. 5) The method described in above item (7), wherein the fine slit structure is formed from fine ITO slits formed in horizontal direction. 6) The method described in above item (7), wherein the length of each of the fine ITO slits is approximately equal to the horizontal length of the pixel electrode. 7) The method described in above item (7), wherein at least one of the substrates has 0.1- to 5-micron high protrusions protruding into the gap between the substrates. In today's MVA, light transmittance is low because banks or ITO slits are arranged in complicated manner so that, to achieve a wider viewing angle, the liquid crystal molecules tilt in four different directions when a voltage is applied. To simplify this structure, a structure such as shown in FIGS. 30 and 31, in which the liquid crystal molecules tilt in two different directions when a voltage is applied, has been considered. In MVA, the direction in which the liquid crystal molecules tilt is sequentially defined by the electric field formed on the banks or ITO slits in the order of increasing distance from the banks or slits. If the spacing between the banks or ITO slits is very wide as shown in FIGS. 30 and 31, it takes time to propagate the molecular tilt throughout the liquid crystal, and this greatly slows the panel response when a voltage is applied. In view of this, a technique has been employed in which a liquid crystal composition containing a polymerizable monomer is injected and, while applying a voltage, the monomer is polymerized, thereby fixing the direction in which the liquid crystal molecules tilt. Another problem has been that since liquid crystal molecules are caused to tilt in a direction rotated 90° from the intended direction due to the electric field formed at a pixel electrode edge near the data bus line, a relatively large dark area is formed in the pixel, as illustrated in FIG. 32 which shows the pixel observed under a microscope. In view of this, fine slits are formed in the ITO pixel electrode on the TFT side substrate to control the molecular alignment by means of electric fields. When fine slits are formed in the ITO pixel electrode, the liquid crystal molecules tilt in parallel to the fine slits. Furthermore, since the alignment direction of all the liquid crystal molecules is determined by the electric fields, the effects of the electric field formed at the pixel edge can be minimized. When a high voltage is applied abruptly, the liquid crystal molecules are caused to tilt wildly by electrostatic energy. Those liquid crystal molecules that are tilted in the direction opposite to the direction in which they should have been tilted attempt to stand up and tilt in the right direction because the molecules in that state are unstable from the viewpoint of energy. It takes much elastic energy for them to stand up and tilt in the right direction because, in the process, they must overcome the electrostatic energy. If they cannot overcome the electrostatic force, the liquid crystal molecules tilted in the opposite direction will enter a metastable state and remain in that state. However, if a voltage slightly higher than the threshold is applied, the liquid crystal molecules tilted in the opposite direction can be caused to stand up and tilt in the right direction by overcoming the electrostatic energy with small elastic energy. Once the liquid crystal molecules are tilted in the right direction, they will not tilt in the opposite direction if the voltage is raised. Therefore, when the monomer is polymerized with the liquid crystal molecules tilted in the right direction, the state of alignment in the right direction is memorized, and when the voltage is applied next time, the liquid crystal molecules will not tilt in the opposite direction. In view of this, after the alignment is set by applying a voltage slightly higher than the threshold voltage, if the voltage is raised to a prescribed level and, in this condition, the polymerizable monomer is polymerized, good molecular alignment can be achieved. As for the fine ITO slits, if the slit width is too small, the slits may break, and conversely, if the slit width is made too large, the liquid crystal molecules may not tilt in the direction parallel to the slits. Further, if the fine ITO slits are made too close together, the risk of shorts between them increases, and conversely, if the slits are spaced too far apart, the liquid crystal molecules may not tilt in the direction parallel to the slits. It is therefore preferable that the fine slits and fine electrodes be each formed to have a width within a range of 0.5 microns to 5 microns. The third aspect of the invention discloses the following methods as specific implementations thereof. 1) The method described in above item (8), wherein at least one of the plurality of light radiation steps is performed while applying a voltage to the liquid crystal layer. 2) The method described in above item (8), wherein the plurality of light radiation steps are performed without applying a voltage, either before or after or both before and after the light radiation that is performed in the presence of an applied voltage. 3) The method described in above item (8), wherein the plurality of light radiation steps are respectively performed with different light intensities. 4) The method described in above item (8), wherein the light radiation that is performed in the presence of an applied voltage is performed with a light intensity of 50 mW/cm2 or higher. 5) The method described in above item (8), wherein the light radiation that is performed without applying a voltage is performed with a light intensity of 50 mW/cm2 or lower. 6) The method described in above item (8), wherein the liquid crystal is an N-type liquid crystal, and the liquid crystal molecules are substantially vertically aligned in the absence of an applied voltage. 7) The method described in above item (8), wherein the liquid crystal display device is an active matrix LCD in which an array of TFTs as switching devices is formed on one of the two substrates. 8) The method described in above item (8), wherein the polymerizable monomer is a liquid crystalline or non-liquid-crystalline monomer, and is polymerized by ultraviolet radiation. 9) The method described in above item (8), wherein the polymerizable monomer is bifunctional acrylate or a mixture of bifunctional acrylate and monofunctional acrylate. To prevent polymer image sticking, it is preferable that there be no residual monomers and all monomers be polymerized. It was experimentally found that if polymerization is performed with insufficient UV radiation or with strong UV radiation but for a short period, unreacted monomers will remain due to insufficient radiation time, and therefore that it is preferable to perform polymerization with low UV strength for a sufficient period of time. However, if the amount of radiation is increased enough that no unreacted monomers remain, then there arises the problem that the contrast decreases, but this problem occurs when the UV radiation is performed in the presence of an applied voltage. In view of this, in the present invention, the UV radiation for polymerization is performed in a plurality of steps. By performing the radiation steps, some in the presence of an applied voltage and others in the absence of an applied voltage, the residual monomer problem can be solved without excessively reducing the pretilt of liquid crystal molecules. It is also preferable to vary the UV radiation strength between the steps. For example, after performing the first radiation step with low UV strength, the second radiation is performed with high UV strength in the presence of an applied voltage, which is followed by the radiation performed with low UV strength. Since a plurality of panels can be processed together in the radiation step performed in the absence of an applied voltage, the increase in the radiation time in this step does not become a problem; this means that the radiation time in the step performed in the presence of an applied voltage, which is the rate-determining step, can be reduced by increasing the UV radiation strength. In the method of the present invention, pretilt decreases during the UV radiation performed in the presence of an applied voltage, but no change occurs in the pretilt during the UV radiation performed in the absence of an applied voltage. Accordingly, the UV radiation process is divided into a plurality of steps, and the time of UV radiation is reduced when performing it in the presence of an applied voltage and increased when performing it in the absence of an applied voltage; by so doing, the pretilt angle is prevented from becoming too large, and the monomers can be completely polymerized, leaving no unreacted monomers. Alternatively, if preliminary radiation is performed to slightly promote the reaction of the monomers preparatory to the UV radiation performed in the presence of an applied voltage, unreacted residual monomers can be further reduced. The effect of performing the UV radiation in intermittent fashion will be described below. In the case of a TFT-LCD, if UV is radiated from either the TFT side or the CF side, there remain unradiated portions because of the presence of light blocking portions. Unreacted monomers in these portions migrate into the display area as the time elapses, and eventually cause image sticking. However, when a time interval is provided between the radiation steps as described above, unreacted monomers are allowed to migrate into the display area during that interval, and are exposed to UV radiation, and eventually, almost all monomers hidden behind the light blocking portions are reacted, achieving an LCD substantially free from image sticking. Thus, according to the present invention, a polymer-fixed MVA-LCD having high contrast and free from image sticking can be achieved, and besides, the time of the polymerization step can be reduced compared with the prior art. The fourth aspect of the invention discloses the following devices as specific implementations thereof. 1) The device described in above item (9), wherein the injection ports are spaced away from a display edge by a distance not greater than two-fifths of the length of the side in which the injection ports are formed. 2) The device described in above item (10), wherein the area where the cell gap is not larger than the cell gap of the display area is spaced away from a cell forming seal by a distance not greater than 0.5 mm. 3) The device described in any one of the above items (9) to (12), wherein the liquid crystal composition contains a non-liquid-crystal component or a component whose molecular weight and surface energy are different from those of a liquid-crystal component. In the device (9) of the present invention, to reduce display unevenness which could occur after polymerization of the polymerizable component due to separation of the liquid crystal and the polymerizable component, the liquid crystal composition must be thoroughly stirred at the initial stage of the injection process of the liquid crystal composition so that abnormal concentration portions of the polymerizable component and liquid crystal will not be formed, and so that localized increases in speed will not occur during the injection process. In the above device, this is achieved by optimizing the number of injection ports and the positions of the injection ports. In the devices (10) and (11) of the present invention, to reduce display unevenness which could occur after polymerization of the polymerizable component due to separation of the liquid crystal and the polymerizable component, it becomes necessary, at the initial stage of the liquid crystal injection process, to prevent abnormal concentration portions of the polymerizable component and liquid crystal from forming and migrating from the frame edge into the display area resulting in agglomeration of the abnormal portions, and also to prevent the separation of the liquid crystal and polymerizable component due to increases in speed in the frame edge portion. In the above devices, therefore, to reduce the display unevenness, the cell thickness at the frame edge is made not greater than that of the display area, the distance between the frame edge and the seal is made not greater than a predetermined value, and the frame edge portion is filled with the auxiliary seal. In the device (12) of the present invention, any abnormal concentration portion of the polymerizable component and liquid crystal is guided outside the display area before polymerizing the polymerizable component, thereby preventing the occurrence of display unevenness. According to the invention, in the liquid crystal display device in which the polymerizable component dispersed in the liquid crystal is photopolymerized or thermally polymerized while applying a voltage, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage, display unevenness does not occur near the side where the injection ports for the liquid crystal composition are formed. Accordingly, the liquid crystal display device of the invention can achieve high display quality. The fifth aspect of the invention discloses the following methods as specific implementations thereof. 1) The method described in above item (13), wherein the step of radiating the ultraviolet light to the liquid crystal composition injected between the two substrates is divided in two or more steps and performed by using ultraviolet light of different intensities. 2) The method described in above item (13), wherein the step of radiating the ultraviolet light to the liquid crystal composition injected between the two substrates is divided in two steps consisting of the step of radiating the ultraviolet light while applying to the liquid crystal molecules a voltage not smaller than the threshold value of the liquid crystal molecules and the step of radiating the ultraviolet light without applying a voltage to the liquid crystal molecules. 3) The method described in above item (13), wherein the step of radiating the ultraviolet light to the liquid crystal composition injected between the two substrates is divided in two steps and performed by applying respectively different voltages to the liquid crystal molecules. 4) The method described in above item (13), wherein the step of radiating the ultraviolet light for polymerizing the ultraviolet polymerizable resin contained in the liquid crystal composition injected between the two substrates is divided in two or more steps and performed by using a plurality of ultraviolet radiation units of different light intensities. 5) The method described in above item (13), wherein the ultraviolet radiation to the liquid crystal composition injected between the two substrates is applied from the array substrate side. 6) The method described in above item (13), wherein the second substrate is constructed from an array substrate on which the color filter layer is formed, the common electrode being formed on the first substrate, and the ultraviolet radiation to the liquid crystal composition injected between the two substrates is applied from the first substrate side. According to the present invention, the polymer material added to control the tilt angle and azimuth angle of the liquid crystal molecules can take a structure that suitably controls the tilt angle of the liquid crystal molecules. For example, if light is radiated sufficiently in the presence of an applied voltage, a rigid cross-linked structure can be formed, but processing takes too much time, and the cost increases because the number of processing units must be increased for mass production or because the processing capacity decreases. As described above, according to the present invention, a fast response liquid crystal display device can be achieved that is free from image sticking, has a wide viewing angle made possible by reliable four-domain technology, provides high contrast by vertical alignment, and has the alignment of the liquid crystal molecules controlled using a polymer. The sixth aspect of the invention discloses the following devices as specific implementations thereof. 1) The device described in any one of the above items (14) to (21), wherein the liquid crystal layer is sandwiched between a substrate in which a color filter layer of red, blue, and green is formed on a TFT substrate, and a substrate on which a common electrode is formed. In the devices (14) to (16) of the present invention, to prevent the formation of an abnormal domain in the liquid crystal and to align the liquid crystal in the desired direction, it is essential that any area where the cell thickness varies, which could become the start point of an abnormal domain, be located at a domain boundary when the liquid crystal is aligned in the desired direction. This serves to alleviate the problems of low brightness, slow response speed, and display unevenness caused by the presence of an abnormal domain. In the devices (17) and (18) of the present invention, if a liquid crystal domain occurs, the area of that domain must be minimized. To achieve this, provision must be made so that more than one structure that could become the start point of an abnormal domain will not be contained in the same alignment sub-region. This serves to alleviate the problems of low brightness, slow response speed, and display unevenness caused by the presence of an abnormal domain. In the device (19) of the present invention, the number of contact holes that could become the start points of abnormal domains is reduced to one, thus making it possible to reduce the number of abnormal domains and increase the numerical aperture. In the device (20) of the present invention, to prevent the numerical aperture from decreasing due to the presence of the metal electrode within the display pixel, it is effective to wire the metal electrode along the region within the pixel electrode that will appear as a dark line even in the presence of an applied voltage. In the device (21) of the present invention, to prevent the formation of an abnormal domain in the liquid crystal and to align the liquid crystal in the desired direction, it is essential that any electrode having the same potential as the pixel electrode be not formed in the slit portion of the pixel electrode. This prevents an abnormal domain from being formed by an electric field arising from the electrode having the same potential as the pixel electrode, and serves to alleviate the problems of low brightness, slow response speed, and display unevenness caused by the presence of an abnormal domain. As described above, according to the present invention, in the liquid crystal display device in which the photopolymerizable component dispersed in the liquid crystal is photopolymerized while applying a voltage, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage, it becomes possible to prevent the formation of abnormal domains in the liquid crystal and align the liquid crystal in the desired direction, and the liquid crystal display device of the invention can thus achieve high display quality. The seventh aspect of the invention discloses the following methods as specific implementations thereof. 1) The method described in above item (22), wherein the additional ultraviolet radiation is applied using ultraviolet light whose wavelength is different from that of the ultraviolet light used for the polymerization of the monomer before the application of the additional ultraviolet radiation. 2) The method described in above item (22), wherein the ultraviolet light used in the additional ultraviolet radiation has a spectrum having a maximum energy peak at 310 to 380 nm. 3) The method described in above item (22), wherein the ultraviolet light used in the additional ultraviolet radiation has a spectrum having a maximum energy peak at 350 to 380 nm. 4) The method described in above item (22), wherein the ultraviolet light used in the additional ultraviolet radiation has a spectrum having a maximum energy peak at 310 to 340 nm. 5) The method described in above item (22), wherein the additional ultraviolet radiation is applied for 10 minutes or longer. 6) The method described in above item (22), wherein substrate surfaces are treated for vertical alignment in accordance with a vertical alignment mode, and liquid crystals in a non-display area also are substantially vertically aligned. In the method of the present invention, after performing the polymerization step for alignment control, additional ultraviolet radiation is applied as an aftertreatment to react residual monomers. The additional radiation is performed by only radiating ultraviolet light to the liquid crystal component, without driving the liquid crystal panel. The radiation should be applied for a relatively long time by using light that efficiently emits ultraviolet light only of a wavelength necessary for polymerization (i.e., the light that does not contain visible light components, etc.) and whose intensity is not very strong. Generally, a radiation time of 10 minutes to 24 hours is preferred, though it depends on the intensity of the ultraviolet light used. In this method, since the radiated light contains hardly any wavelength components longer than the ultraviolet light, the radiation does not cause a temperature rise and it becomes possible to radiate light at an effective wavelength with a relatively strong intensity. As a result, residual monomers can be polymerized without causing a temperature rise, and a panel virtually free from image sticking can be achieved. Furthermore, since the additional ultraviolet radiation does not require driving the panel but can be implemented using a simple apparatus, many such radiation apparatuses can be installed so that many panels can be treated at the same time even when radiation takes a long time; accordingly, the additional ultraviolet radiation does not affect the overall time of the panel fabrication process and degrade the productivity. [Embodiments] The first aspect of the invention will be described further with reference to specific embodiments thereof. Embodiment 1 As shown in FIG. 9, gate bus lines and data bus lines are arranged in an matrix array on a first substrate, and the respective bus lines are bundled at one end. A TFT is located at each intersection of the bus lines, and a pixel electrode is formed via the TFT. On a second substrate on the opposite side is formed a common electrode which forms an electrical capacitance to each of the pixel electrodes, and a pad for applying a voltage to it is drawn out in the lower left corner. The pixel electrodes also form a layer called a Cs bus line and an auxiliary capacitance Cs within the first substrate. It can be said that the Cs bus line is another common electrode. The Cs bus line is drawn out as a pad (Cs) in the upper right corner. The cross section of the thus constructed liquid crystal panel is the same as that shown in FIG. 2; here, the first substrate corresponds to the bottom substrate and the second substrate to the substrate on which color filters are deposited. On the surface of each substrate is formed an alignment film that determines the initial alignment of the liquid crystal (the liquid crystal alignment before the liquid crystal is exposed to light radiation); in the illustrated example, a polyimide alignment film exhibiting vertical alignment is used. Here, a liquid crystal material that has a negative dielectric anisotropy Δ∈ of −3 to −5, and to which a trace amount (0.1 to 1.0%) of liquid crystalline acrylic material exhibiting photosensitivity has been added, is used as the liquid crystal. In the thus constructed liquid crystal panel, when an AC voltage (rectangular wave) of ±20 V is applied to the common electrode pad (C) and 0 V to the pad (Cs), the voltage applied to the liquid crystal part, as earlier described, is given by Zlc/(Zlc+Zc)×AC voltage If the liquid crystal capacitance Clc=250 fF and the auxiliary capacitance Cs=250 fF, then it can be seen from calculation that a voltage of about ±10 V has been applied to the liquid crystal part. When UV radiation is applied to the liquid crystal panel in this condition, the liquid crystalline acrylic material polymerizes by tilting in the direction in which the liquid crystal molecules are tilted. By removing the applied voltage after the radiation, a condition in which the initial alignment is slightly tilted from the vertical alignment can be achieved. The display characteristics of the completed panel are shown in FIGS. 10 and 11; as can be seen, the characteristics are influenced by the voltage applied when polymerizing the liquid crystalline acrylic material, and when the AC voltage (rectangular wave) of ±20 V is applied, a panel having a white brightness of 320 cd/m2 and a black brightness of 0.53 cd/m2 (backlight of 5000 cd/m2) can be obtained. Embodiment 2 Compared with the structure of the first embodiment shown in FIG. 1, the common electrode and the Cs bus line are completely insulated from each other in the structure shown in FIG. 12 (generally, they are short-circuited using conductive particles or silver paste). It is preferable to completely insulate the common electrode from the Cs bus line as illustrated here, because deterioration of the applied AC voltage can then be alleviated. In particular, the resistance per Cs bus line is often of the order of several thousand ohms and, depending on the magnitude of leakage, the applied voltage drops. Embodiment 3 As described above, it is desirable that the common electrode and the Cs bus line be electrically insulated from each other, considering the voltage application when exposing the liquid crystal to radiation. This method, however, requires that a separate pattern from the voltage supply pattern to the Cs bus line be formed for the common electrode that needs to be supplied with currents from the four sides. In view of this, if the common electrode is shorted to the Cs bus line after the radiation, as shown in the example shown here, supply of currents from the four sides can be easily accomplished. More specifically, as shown in the example of. FIG. 13, portions that can be shorted using a laser are provided in advance within the panel structure. For this purpose, it is generally practiced to electrically connect the top and bottom substrates by using silver paste or conductive spacer means. On the other hand, in the example shown in FIG. 14, the connection is made at the terminal side. In the example shown here, the connection between the common electrode and the Cs bus line is made outside the panel. Embodiment 4 In a liquid crystal panel having the structure shown in FIG. 15 which is similar to that of the first embodiment, an AC voltage (rectangular wave) of ±8 V is applied to the common electrode pad (C) and 0 V to the pad (Cs), and further, −5 V is applied to the gate bus line. As earlier described, the voltage applied to the liquid crystal part is given by Zlc/(Zlc+Zc)×AC voltage With the voltage applied to the gate bus line, the current that flows from the transistor to the data bus line can be suppressed. As in the first embodiment, when UV radiation is applied to the liquid crystal panel, the liquid crystalline acrylic material polymerizes by being dragged in the direction in which the liquid crystal molecules are tilted. Embodiment 5 The foregoing embodiments have been described specifically dealing with the case of the liquid crystal to which a liquid crystalline acrylic material has been added. It will, however, be recognized that any of the methods described in the above embodiments can be applied to a panel, such as a polymer-dispersed liquid crystal display panel, that contains a photosensitive material, or to ferroelectric panel that needs treatment for alignment. Embodiment 6 In the method of the first embodiment, if the frequency of the AC voltage applied is high, the high resistance of the Cs bus line becomes a problem, and insufficient writing results. Conversely, if the frequency is low, voltage leaks occur at high resistance connection portions, resulting in an inability to write a uniform voltage over the entire surface of the panel. Considering that the wiring resistance varies depending on the material, etc., the relationship between the frequency and brightness was measured while varying the applied AC voltage. The results are shown in FIG. 16. As can be seen, it is preferable to set the AC frequency of the AC voltage within the range of about 1 Hz to 1 kHz. Embodiment 7 This embodiment concerns an example in which a wiring defect is made invisible by applying a DC voltage while holding the wiring lines and electrodes on the second substrate at the same potential. In this example, the DC voltage is applied between the common electrode and the three bus lines. Here, 10 V is applied to the common electrode, and 0 V is applied to the three bus lines. Then, as the voltage actually applied to the liquid crystal is the same as the model explained in the description of the first embodiment, a panel having substantially the same display characteristics (white brightness of 320 cd/m2 and black brightness of 0.53 cd/m2) can be obtained. Needless to say, in this case, shorts between the bus lines, etc. do not present any problem because they are held at the same voltage. Embodiment 8 This embodiment is the same as the seventh embodiment, except that the data bus lines are bundled at the opposite ends as well, as shown in FIG. 18. With this arrangement, if there is a break in a data bus line, the voltage can be supplied from the opposite end. In this case, the bundled portion should be separated afterwards by cutting the glass. Embodiment 9 One method of avoiding the cutting process in the eighth embodiment is to connect the data bus lines via high resistance at the opposite end as shown in FIG. 19, instead of bundling them together. In the case of a DC voltage, if a sufficient time elapses, the potential can be equalized despite the presence of high resistance connections, as explained in connection with FIG. 5. Using this, it is also possible to apply a Dc voltage by forming a pattern such as shown in FIG. 20 or 21. In FIG. 20, the data bus lines, the gate bus lines, the Cs bus lines (including the repair line described later), and the common electrode are all connected via high resistance such as ESD circuits. In this example, radiation is applied to the liquid crystal while applying 10 V to the data bus lines, 10 V to the gate bus lines (including the repair line described later), and 0 V to the common electrode. In FIG. 21, the data bus lines, the gate bus lines, and the Cs bus lines (including the repair line described later) are all connected via high resistance such as ESD circuits. However, these bus lines are insulated from the common electrode. In this example, radiation is applied to the liquid crystal while applying 10 V to the data bus lines, and 0 V to the common electrode. In each of the examples of FIGS. 20 and 21, the bus lines on the second substrate are all held at the same potential. Embodiment 10 In this embodiment, voltages are applied not only to the data bus lines, gate bus lines, Cs bus lines, and common electrode, but also to the repair line, as shown in FIG. 22. The repair line is usually formed at both ends of the data bus lines or at the end opposite from the signal input end. In the device shown in the figure, the repair line is located at the end opposite from the signal input end. In a typical example of repair, any defect, including a line defect caused by an interlayer short, is converted to a defect of type b (data bus line breakage), as explained with reference to FIG. 7, and the defective line is connected to the repair line, as shown in FIG. 20. In this case, since the voltage from the signal input end does not propagate beyond the broken point, the voltage may be rerouted via an ESD circuit or the like within the panel, as in other embodiments earlier described, but compared with that method, applying a voltage directly to the repair line is a much more reliable method. Based on the above concept, in the device of FIG. 22, a voltage is applied to the repair line directly or via a high resistance connection. In the figure, the bus lines and the TFTs are arranged on the second substrate. A transparent electrode as the common electrode is formed on the first substrate. An alignment film is formed on each substrate by printing, spinning, or other techniques. Liquid crystal with a trace amount of liquid crystalline acrylic material added to it is sandwiched between the two substrates. Next, 0 V is applied to the common electrode, while a DC voltage of 10 V is applied to the portions connected via high resistance to the gate bus lines, data bus lines, and repair line. After applying the voltage to the liquid crystal in this way, UV radiation is applied to the liquid crystal part. Embodiment 11 This embodiment concerns an example in which a CF-ON-TFT structure is employed as the panel structure, as shown in FIG. 23. As previously shown in FIG. 4, a shift in TFT threshold value occurs when ultraviolet radiation is directly applied when the TFTs are ON. When color filters are formed on the TFT substrate in such a manner as to cover the TFTs, most of the ultraviolet radiation falling on the substrate can be cut off, as a result of which shifting in the threshold value can be suppressed. In FIG. 23, the TFTs are arranged on the second substrate, and the color filters are formed over the TFTs, on top of which pixel electrodes are formed. A transparent electrode as the common electrode is formed on the first substrate. An alignment film is formed on each substrate by printing, spinning, or other techniques. Liquid crystal with a trace amount of liquid crystalline acrylic material added to it is sandwiched between the two substrates. Next, 0 V is applied to the common electrode and 20 V to the gate bus lines, while an 30-Hz AC square wave voltage of ±10 V is applied to the data bus lines. The data bus lines are bundled at both ends, as shown in FIG. 18. After applying the voltage to the liquid crystal in this way, UV radiation is applied from the first substrate side. Embodiment 12 This embodiment concerns an example in which not only is a light blocking film formed on the TFTs in order to suppress the shifting in TFT threshold, but the same signal as input to the data bus lines is applied to the repair line, as shown in FIG. 24, in order to apply a voltage uniformly to a line defect portion as well. As in the 11th embodiment, the TFTs are arranged on the second substrate, and the color filters are formed over the TFTs, on top of which pixel electrodes are formed. A transparent electrode as the common electrode is formed on the first substrate. An alignment film is formed on each substrate by printing, spinning, or other techniques. Liquid crystal with a trace amount of liquid crystalline acrylic material added to it is sandwiched between the two substrates. Next, 0 V is applied to the common electrode and 20 V to the gate bus lines, while an 30-Hz AC square wave voltage of ±10 V is applied to the repair line as well as to the data bus lines. Here, the repair line is connected to the bus line to be repaired. After applying the voltage to the liquid crystal in this way, UV radiation is applied from the first substrate side. Next, the second aspect of the invention will be described with reference to specific embodiments thereof. In each of the following embodiments, the display device uses vertical alignment films and a liquid crystal material having a negative dielectric anisotropy, and since the polarizers are arranged in a crossed Nicol configuration and attached to both sides of the liquid crystal panel, the display device is normally black. The polarization axis of each polarizer is oriented at 45° to the bus lines. The panel size is 15 inches in diagonal, and the resolution is XGA. Liquid crystalline acrylate monomer UCL-001 manufactured by Dainippon Ink and Chemicals, Inc. was used as the polymerizable monomer, and a liquid crystal material having negative Δ∈ was used as the liquid crystal. Embodiment 13 A liquid crystal panel having an ITO pattern such as shown in FIG. 25 was fabricated. Since the gap between the data bus line and the ITO is approximately equal to the width of each fine ITO slit, liquid crystal molecules tilt in the direction parallel to the data bus line even in the portion corresponding to the gap between the data bus line and the ITO, that is, all the liquid crystal molecules tilt in the same direction, preventing the formation of dark areas. To achieve symmetrical viewing angle characteristics, the area where the liquid crystal molecules tilt toward the top of FIG. 23 and the area where the liquid crystal molecules tilt toward the bottom of FIG. 25 are substantially equal in size. In FIG. 25, the fine electrodes are connected together at the center of the pixel. As shown in FIG. 26 which is a cross-sectional view showing one example of the device of FIG. 25, the direction in which the liquid crystal molecules tilt can be controlled by an electric field alone, but as shown in FIG. 27 which is a cross-sectional view showing another example of the device of FIG. 25, protruding banks may be formed in order to more clearly define the direction in which the liquid crystal molecules tilt. Instead of providing the banks, the alignment film may be rubbed in the direction shown, or an optical alignment technique may be used. A voltage 0.1 V higher than the threshold voltage was applied to the liquid crystal composition filled into the panel, and one minute was allowed to pass; then, after confirming by observation under a microscope that the alignment had been controlled in the desired direction, the voltage was raised to 3 V at a rate of 0.01 V per second, and then to 10 V at a rate of 0.1 V per second, and with the voltage of 10 V applied, ultraviolet radiation was applied to polymerize the monomer. The fabrication of a liquid crystal panel free from alignment disruptions was thus achieved. Embodiment 14 A liquid crystal panel having an ITO pattern such as shown in FIG. 28 was fabricated. A voltage 0.1 V higher than the threshold voltage was applied to the liquid crystal composition filled into the panel, and one minute was allowed to pass to allow the alignment of the liquid crystal molecules to stabilize; after that, the voltage was raised to 3 V at a rate of 0.01 V per second, and then to 10 V at a rate of 0.1 V per second, and with the voltage of 10 V applied, ultraviolet radiation was applied to polymerize the monomer. The fabrication of a liquid crystal panel free from alignment disruptions was thus achieved. Next, the third aspect of the invention will be described with reference to specific embodiments thereof. Embodiments 15 to 17 and Comparative Examples 1 and 2 Embodiments of the present invention, each using a 15-inch XGA-LCD, are shown in FIG. 33 for comparison with comparative examples fabricated according to the prior art method. An N-type liquid crystal material having negative Δ∈ was used as the liquid crystal. Liquid crystalline acrylate monomer UCL-001 manufactured by Dainippon Ink and Chemicals, Inc. was used as the polymerizable monomer. The concentration of the monomer in the liquid crystal composition was 0.1 to 2% by weight. A photopolymerization initiator was added at a concentration of 0 to 10% relative to the weight of the monomer. The UV radiation conditions and the obtained results are shown in Table 1. [Table 1] TABLE 1 1ST UV RADIATION 2ND UV RADIATION AMOUNT AMOUNT UV OF UV UV OF UV VOLTAGE INTENSITY RADIATION VOLTAGE INTENSITY RADIATION EXAMPLE NO. Run (V) (mW/cm2) (mJ/cm2) (V) (mW/cm2) (mJ/cm2) EMBODIMENT {circle over (1)} 10 100 4000 0 10 4000 15 {circle over (2)} 10 100 4000 0 10 6000 {circle over (3)} 10 100 4000 0 10 8000 {circle over (4)} 10 10 2000 0 100 4000 {circle over (5)} 10 10 2000 0 100 6000 {circle over (6)} 10 10 2000 0 100 8000 EMBODIMENT {circle over (7)} 0 10 500 10 100 4000 16 {circle over (8)} 0 10 1000 10 100 4000 EMBODIMENT {circle over (9)} 0 10 500 10 100 4000 17 {circle over (10)} 0 10 500 10 100 4000 {circle over (11)} 0 10 500 10 100 4000 COMPARATIVE 10 10 4000 — — — EXAMPLE 1 COMPARATIVE 10 10 8000 — — — EXAMPLE 2 3RD UV RADIATION AMOUNT RADIATION UV OF UV TIME WITH VOLTAGE INTENSITY RADIATION BURN- APPLIED EXAMPLE NO. Run (V) (mW/cm2) (mJ/cm2) IN CONTRAST VOLTAGE EMBODIMENT {circle over (1)} — — — 7% 600 40 15 {circle over (2)} — — — 6% 600 40 {circle over (3)} — — — 6% 600 40 {circle over (4)} — — — 8% 700 200 {circle over (5)} — — — 7% 700 200 {circle over (6)} — — — 7% 700 200 EMBODIMENT {circle over (7)} — — — 9% 700 40 16 {circle over (8)} — — — 9% 700 40 EMBODIMENT {circle over (9)} 0 10 4000 7% 700 40 17 {circle over (10)} 0 10 6000 6% 700 40 {circle over (11)} 0 10 8000 6% 700 40 COMPARATIVE — — — 18% 600 400 EXAMPLE 1 COMPARATIVE — — — 6% 300 800 EXAMPLE 2 In the first comparative example, the applied voltage during UV radiation was 10 V, the UV intensity was 10 mW/cm2, and the amount of radiation was 4000 mJ/cm2. The radiation time was about 400 seconds, and a contrast of about 600 was obtained, but residual monomers were left and the image sticking was as large as 18%. When the amount of UV radiation was increased to 8000 mJ/cm2, as in the second comparative example, the image sticking decreased to 6%; however, in this case, the contrast decreases, and the radiation time becomes as long as about 800 seconds. The method of the 15th embodiment is a method in which a voltage of 10 V is applied during the first radiation to provide a desired pretilt, and the second radiation is performed without applying an electric field to eliminate residual monomers. As shown in Table 1, the first radiation was performed by applying high intensity uv in some examples and low intensity UV in others; in the case of the high intensity UV radiation (100 mW/m2), the radiation time, with an applied voltage, was about 40 seconds, and good results were obtained for both the image sticking and the contrast. On the other hand, in the case of the low intensity UV radiation (10 mW/m2), the radiation time, with an applied voltage, increased up to 200 seconds, but it was not longer than one half the time required in the comparative examples, and good results were obtained for both the image sticking and the contrast. In the method of the 16th embodiment, the first radiation is performed without applying an electric field, but the second radiation is performed while applying a voltage. More specifically, the first radiation is performed by applying a small amount of radiation to cause the monomers to react to a certain extent, thereby making the monomers in unradiated areas easier to react and, thereafter, UV radiation is applied in the presence of an applied voltage. Since post-radiation is not performed, the image sticking somewhat increases, but the contrast is further improved. In the method of the 17th embodiment, both the post-radiation and pre-radiation are performed. Good results were obtained for both the image sticking and the contrast. Next, the fourth aspect of the invention will be described with reference to specific embodiments thereof. Embodiment 18 TFT devices, data bus lines, gate bus lines, and pixel electrodes were formed on one substrate. A color layer and a common electrode were formed on the other substrate. An empty cell was fabricated by laminating the two substrates together with 4-μm diameter spacers interposed therebetween. An acrylic photopolymerizable component exhibiting the nematic liquid crystalline state was mixed in an amount of 0.3 weight percent into a negative-type liquid crystal material, and the thus prepared liquid crystal composition containing the photopolymerizable component was injected into the cell to fabricate a liquid crystal panel. As shown in FIG. 34, the panel was provided with three injection ports which were formed in positions 68 mm to 80 mm, 110 mm to 122 mm, and 152 mm to 164 mm, respectively, on a 232-mm long side. A gate voltage of 30 VDC, a data voltage of 10 VDC, and a common voltage of 5 VDC were applied to the panel to cause the liquid crystal molecules in the panel to tilt, and in this condition, 300-nm to 450-nm ultraviolet radiation of 2000 mJ/cm2 was applied from the common substrate side. The ultraviolet polymerizable monomer was thus polymerized. Next, polarizers were attached to complete the fabrication of the liquid crystal panel. It was confirmed that the thus fabricated liquid crystal panel achieved a high display quality free from display defects such as display unevenness in the corners. Embodiment 19 TFT devices, data bus lines, gate bus lines, and pixel electrodes were formed on one substrate. A color layer and a common electrode were formed on the other substrate. An empty cell was fabricated by laminating the two substrates together with 4-μm diameter spacers interposed therebetween. An acrylic photopolymerizable component exhibiting the nematic liquid crystalline state was mixed in an amount of 0.3 weight percent into a negative-type liquid crystal material, and the thus prepared liquid crystal composition containing the photopolymerizable component was injected into the cell to fabricate a liquid crystal panel. As shown in FIG. 35, the BM portion of the panel frame edge was formed by laminating CF resin layers; the cell gap at this portion was 2.4 μm (the cell gap in the display area was 4.0 μm) and the distance to the seal was 0.2 mm. A gate voltage of 30 VDC, a data voltage of 10 VDC, and a common voltage of 5 VDC were applied to the panel to cause the liquid crystal molecules in the panel to tilt, and in this condition, 300-nm to 450-nm ultraviolet radiation of 2000 mJ/cm2 was applied from the common substrate side. The ultraviolet polymerizable monomer was thus polymerized. Next, polarizers were attached to complete the fabrication of the liquid crystal panel. It was confirmed that the thus fabricated liquid crystal panel achieved a high display quality free from display defects such as display unevenness in the corners. In the above structure, it will be appreciated that the same effect can be obtained if a CF resin film is deposited on a metal BM of Cr or the like instead of forming the panel BM portion by laminating the resin layers. Embodiment 20 TFT devices, data bus lines, gate bus lines, and pixel electrodes were formed on one substrate. A color layer and a common electrode were formed on the other substrate. An empty cell was fabricated by laminating the two substrates together with 4-μm diameter spacers interposed therebetween. An acrylic photopolymerizable component exhibiting the nematic liquid crystalline state was mixed in an amount of 0.3 weight percent into a negative-type liquid crystal material, and the thus prepared liquid crystal composition containing the photopolymerizable component was injected into the cell to fabricate a liquid crystal panel. AS shown in FIG. 36, an auxiliary seal was formed on the BM portion of the panel frame edge, to eliminate the cell gap at the BM portion of the frame edge. A gate voltage of 30 VDC, a data voltage of 10 VDC, and a common voltage of 5 VDC were applied to the panel to cause the liquid crystal molecules in the panel to tilt, and in this condition, 300-nm to 450-nm ultraviolet radiation of 2000 mJ/cm2 was applied from the common substrate side. The ultraviolet polymerizable monomer was thus polymerized, and a polymer network was formed within the panel. Next, polarizers were attached to complete the fabrication of the liquid crystal panel. It was confirmed that the thus fabricated liquid crystal panel achieved a high display quality free from display defects such as display unevenness in the corners. Embodiment 21 TFT devices, data bus lines, gate bus lines, and pixel electrodes were formed on one substrate. A color layer and a common electrode were formed on the other substrate. An empty cell was fabricated by laminating the two substrates together with 4-μm diameter spacers interposed therebetween. An acrylic photopolymerizable component exhibiting the nematic liquid crystalline state was mixed in an amount of 0.3 weight percent into a negative-type liquid crystal material, and the thus prepared liquid crystal composition containing the photopolymerizable component was injected into the cell to fabricate a liquid crystal panel. As shown in FIG. 37, pockets were formed in the BM portion of the panel frame edge by using auxiliary seals, to allow liquid crystals of abnormal concentrations to enter these pockets. A gate voltage of 30 VDC, a data voltage of 10 VDC, and a common voltage of 5 VDC were applied to the panel to cause the liquid crystal molecules in the panel to tilt, and in this condition, 300-nm to 450-nm ultraviolet radiation of 2000 mJ/cm2 was applied from the common substrate side. The ultraviolet polymerizable monomer was thus polymerized. Next, polarizers were attached to complete the fabrication of the liquid crystal panel. It was confirmed that the thus fabricated liquid crystal panel achieved a high display quality free from display defects such as display unevenness in the corners. Next, the fifth aspect of the invention will be described with reference to specific embodiments thereof. Embodiment 22 A cross-sectional view of the panel of this embodiment is shown in FIG. 38. The layer structure of the TFT substrate comprises, from the bottom to the top, a gate metal layer of Al—Nd/MoN/Mo, a gate insulating film of SiN, an a-Si layer, a drain metal layer of n+/Ti/Al/MoN/Mo, a protective film layer of SiN, and a pixel electrode layer of ITO. The structure of the CF substrate comprises a color filter layer of red, blue, and green and an ITO film layer that forms the common electrode. FIG. 39 shows a plan view of this panel. According to this pixel electrode pattern, when a voltage is applied, liquid crystal molecules tilt in four different directions a, b, c, and d, as shown in the figure. This achieves a wide viewing angle. The common electrode made of ITO is formed on one of the opposing substrates. A vertical alignment film was deposited on each of the two substrates, spacer beads were applied to one of the substrates, a panel periphery seal was formed on the other substrate, and the two substrates were laminated together. Liquid crystal was injected into the thus fabricated panel. A negative-type liquid crystal material having a negative dielectric anisotropy, with 0.2 weight percent of ultraviolet curable monomer added to it, was used as the liquid crystal. Ultraviolet radiation was applied to the panel, in the presence of an applied voltage, to control the alignment of the liquid crystal. FIG. 40 shows how the liquid crystal alignment is controlled by the polymer. In the initial state where no voltage is applied, the liquid crystal molecules are aligned vertically, and monomers exist as monomers. When a voltage is applied, the liquid crystal molecules tilt in the directions defined by the fine pattern of the pixel electrode, and the monomers tilt in like manner. When ultraviolet radiation is applied in this condition, the tilted monomers are polymerized, thus controlling the alignment of the liquid crystal molecules. Voltage application and ultraviolet radiation patterns such as shown in FIG. 41 can be employed here. In the figure, high intensity ultraviolet radiation refers to the radiation of 300-nm to 450-nm ultraviolet light with an intensity of 30 mW or higher, and low intensity ultraviolet radiation refers to the ultraviolet radiation with an intensity of 30 mW or lower. Further, a high voltage means a voltage applied to the liquid crystal layer that is equal to or greater than the threshold voltage of the liquid crystal, and low voltage means a voltage that is equal to or lower than the threshold voltage of the liquid crystal, or means no application of voltage. The thus fabricated liquid crystal panel was a high quality panel having high brightness and wide viewing angle and free from image sticking. Embodiment 23 To implement the panel fabrication method of the 22nd embodiment, manufacturing equipment comprising two ultraviolet radiation units connected together was used as shown in FIG. 42; here, the first unit can radiate ultraviolet light while applying a voltage, and the second unit has a structure that applies ultraviolet radiation to the panel while transporting the panel on transport rollers with this equipment, a high throughput, space-saving fabrication of the panel can be achieved. Embodiment 24 A cross-sectional view of the panel of this embodiment is shown in FIG. 43. A color filter layer and an overcoat layer are formed over the TFT array, and high transmittance of light can be achieved with this structure. Next, the sixth aspect of the invention will be described with reference to specific embodiments thereof. Embodiment 25 TFT devices, data bus lines, gate bus lines, and pixel electrodes were formed on one substrate. A color layer and a common electrode were formed on the other substrate. An empty cell was fabricated by laminating the two substrates together with 4-μm diameter spacers interposed therebetween. An acrylic photopolymerizable component exhibiting the nematic liquid crystalline state was mixed in an amount of 0.3 weight percent into a negative-type liquid crystal material, and the thus prepared liquid crystal composition containing the photopolymerizable component was injected into the cell to fabricate a liquid crystal panel. FIG. 45 shows a plan view and a cross-sectional view of a pixel in the thus fabricated panel; as shown, the source electrode/pixel electrode contact hole and the Cs intermediate electrode/pixel electrode contact hole are both located at a liquid crystal domain boundary formed by pixel slits. This structure serves to prevent the formation of abnormal domains resulting from the contact holes, and the thus fabricated liquid crystal display device does not contain any abnormal domains and has a high display quality free from display unevenness and degradations in brightness and response speed characteristics. Embodiment 26 TFT devices, data bus lines, gate bus lines, and pixel electrodes were formed on one substrate. A color layer, a common electrode, and alignment controlling banks were formed on the other substrate. An empty cell was fabricated by laminating the two substrates together with 4-μm diameter spacers interposed therebetween. An acrylic photopolymerizable component exhibiting the nematic liquid crystalline state was mixed in an amount of 0.3 weight percent into a negative-type liquid crystal material, and the thus prepared liquid crystal composition containing the photopolymerizable component was injected into the cell to fabricate a liquid crystal panel. FIG. 46 shows a plan view of a pixel in the thus fabricated panel; as shown, the source electrode/pixel electrode contact hole and the Cs intermediate electrode/pixel electrode contact hole are both located at the crossing portions of the banks which correspond to the boundaries of the liquid crystal domains. The portions of the source electrode and the Cs intermediate electrode which are extended into the display area run along the liquid crystal domain boundaries deliberately formed by the pixel electrode slits, and these portions do not cause abnormal domains, nor do they lower the numerical aperture. The thus fabricated liquid crystal display device does not contain any abnormal domains and has a high display quality free from display unevenness and degradations in brightness and in response speed characteristics. Embodiment 27 A liquid crystal panel was fabricated in the same manner as in the 25th embodiment. FIG. 47 shows a plan view of a pixel; as shown, the source electrode/pixel electrode contact hole and the Cs intermediate electrode/pixel electrode contact hole are located in different alignment sub-regions, and if any of them becomes a starting point of an abnormal domain, it will not cause interactions that could lead to the formation of an abnormal domain over a wider area. The thus fabricated liquid crystal display device contains few abnormal domains and has a high display quality virtually free from display unevenness and degradations in brightness and in response speed characteristics. Embodiment 28 TFT devices, data bus lines, gate bus lines, a color layer, and pixel electrodes were formed on one substrate. A common electrode was formed on the other substrate. An empty cell was fabricated by laminating the two substrates together with 4-μm diameter spacers interposed therebetween. An acrylic photopolymerizable component exhibiting the nematic liquid crystalline state was mixed in an amount of 0.3 weight percent into a negative-type liquid crystal material, and the thus prepared liquid crystal composition containing the photopolymerizable component was injected into the cell to fabricate a liquid crystal panel. FIG. 48 shows a plan view and a cross-sectional view of a pixel in the thus fabricated panel; as shown, a contact hole where cell thickness varies, which could cause an abnormal domain, is located at a liquid crystal domain boundary. Further, the pixel electrode, the source electrode, and the Cs intermediate electrode are connected via one contact hole and, thus, the cause of abnormal domains is eliminated and the numerical aperture increased. The source electrode is wired along a liquid crystal domain boundary deliberately formed by pixel electrode slits and located outside the pixel slit area, and this therefore does not cause an abnormal domain, nor does it lower the numerical aperture. The thus fabricated liquid crystal display device does not contain any abnormal domains and has a high display quality free from display unevenness and degradations in brightness and response speed characteristics. Next, the seventh aspect of the invention will be described with reference to specific embodiments thereof. Embodiment 29 A panel comprising a TFT substrate and a color filter substrate, with a vertically aligned liquid crystal of negative Δ∈ sandwiched between the two substrates, was used. Liquid crystalline acrylate monomer UCL-001 manufactured by Dainippon Ink and Chemicals, Inc. was added in an amount of 0.25 weight percent into the liquid crystal layer. While driving the liquid crystal by applying a drive voltage having an effective value of 5.0 V to the liquid crystal layer, ultraviolet light having a maximum energy peak at wavelength 365 nm is projected for 300 seconds to the panel, thereby polymerizing and curing the monomer in a prescribed liquid crystal alignment state. A polyamic acid alignment film exhibiting vertical alignment was used here. The panel cell gap was set at 4.0 μm. The liquid crystal driving mode was normally black mode. Next, as shown in FIG. 49, additional ultraviolet radiation was applied to the panel. Commercially available black lamps (manufactured by Toshiba Lighting and Technology Corporation) were used as the light source for the additional radiation. The maximum energy peak wavelength was 352 nm, and five lamps were arranged, spaced 10 cm apart from each other, to form a surface-area light source, and light was radiated from a distance of 10 cm with an intensity of 5 mW/cm2. When the image sticking ratio of the panel was measured before and after the additional ultraviolet radiation, the image sticking ratio of the panel before the additional ultraviolet radiation was 12%, while the image sticking ratio of the panel after the radiation was reduced to 3%. When the tested panels were left idle for 24 hours, the former was never restored to the original condition, but in the latter, the image sticking was completely erased. Further, the relationship between the amount of ultraviolet radiation and the image sticking ratio was obtained by varying the amount of additional ultraviolet radiation to be applied to the panel. The result is shown in FIG. 50. As can be seen, the image sticking ratio reduces as the amount of ultraviolet radiation increases. Here, the image sticking ratio was obtained in the following manner. A black and white checkered pattern was displayed for 48 hours in the display area. After that, prescribed halftone dots (gray) were displayed over the entire display area, and the difference between the brightness β of the area that was displayed in white and the brightness γ of the area that was displayed in black (β−γ) was divided by the brightness γ of the area that was displayed in black, to obtain the image sticking ratio. Image sticking ratio α=((β−γ)/γ)×100(%) Embodiment 30 The process described in the 29th embodiment was repeated with the difference that commercially available UV-B fluorescent lamps (manufactured by Tozai Densan, Ltd.) ware used instead of the black lamps. The maximum energy peak frequency of this fluorescent lamp was 310 nm. In the panel subjected to the additional ultraviolet radiation of this embodiment, the image sticking ratio was reduced to 2.5%, and when the panel was left idle for 24 hours, the image sticking was completely erased. The fabrication method for the liquid crystal display device according to the first aspect of the invention described above can be summarized as follows: (Item 1) A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light onto the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying AC voltages to the common electrode and the Cs bus line. (Item 2) A method of fabricating a liquid crystal display device as described in item 1, wherein the common electrode and the Cs bus line are insulated from each other or connected via high resistance when radiating the light onto the liquid crystal layer. (Item 3) A method of fabricating a liquid crystal display device as described in item 1, wherein after radiating the light onto the liquid crystal layer, the common electrode and the Cs bus line are electrically connected together. (Item 4) A method of fabricating a liquid crystal display device as described in item 1 wherein, initially, the liquid crystal layer is vertically aligned and, by radiating the light while applying a voltage to the liquid crystal composition containing the photosensitive material, the average angle of the liquid crystal to an alignment film is set smaller than a polar angle of 90°. (Item 5) A method of fabricating a liquid crystal display device as described in item 1, wherein AC frequency when applying the AC voltage is set within a range of 1 to 1000 Hz. (Item 6) A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance with the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; insulating the common electrode from the three bus lines, or connecting the common electrode to the three bus lines via high resistance; and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the three bus lines (the gate bus line, the data bus line, and the Cs bus line) formed on the second substrate. (Item 7) A method of fabricating a liquid crystal display device as described in item 1, wherein adjacent gate bus lines or data bus lines are electrically connected together at both ends thereof. (Item 8) A method of fabricating a liquid crystal display device as described in item 7, wherein after radiating the light onto the liquid crystal layer, the common electrode and the Cs bus line are electrically connected together. (Item 9) A method of fabricating a liquid crystal display device as described in item 6 wherein, initially, the liquid crystal layer is vertically aligned and, by radiating the light while applying a voltage to the liquid crystal composition containing the photosensitive material, the average angle of the liquid crystal to an alignment film is set smaller than a polar angle of 90°. (Item 10) A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with at least one of the data bus and gate bus lines; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the four bus lines (the gate bus line, the data bus line, the Cs bus line, and the repair line) formed on the second substrate. (Item 11) A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance with the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and connecting the common electrode via high resistance to the three bus lines (the gate bus line, the data bus line, and the Cs bus line,) formed on the second substrate, and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and at least one of the bus lines. (Item 12) A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance using the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; electrically connecting adjacent data bus lines at both ends thereof; and radiating light onto the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line. (Item 13) A method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with the data bus line; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; connecting at least one data bus line with at least one repair line by laser radiation or other method; and radiating light onto the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line and repair line (the repair line is at the same potential as the data bus line). (Item 14) A liquid crystal display device fabricated by a method described in any one of items 1 to 13. The fabrication method for the liquid crystal display device according to the second aspect of the invention can be summarized as follows: (Item 15) A method of fabricating a vertical alignment liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition into a gap between two substrates each having a transparent electrode and an alignment control film for causing liquid crystal molecules to align vertically, the liquid crystal composition having a negative dielectric anisotropy and containing a polymerizable monomer; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to the liquid crystal molecules, and wherein: before polymerizing the monomer, a constant voltage not smaller than a threshold voltage but not greater than a saturation voltage is applied between the opposing transparent electrodes for a predetermined period of time and, thereafter, the voltage is changed to a prescribed voltage and, while maintaining the prescribed voltage, ultraviolet radiation or heat is applied to the liquid crystal composition to polymerize the monomer. (Item 16) A method of fabricating a liquid crystal display device as described in item 15, wherein after a constant voltage not smaller than the threshold voltage but not greater than the threshold voltage+1 V is applied between the opposing transparent electrodes for a time not shorter than 10 seconds, the voltage is changed by applying a voltage not smaller than a voltage to be applied to produce a white display state and, while maintaining the voltage, the ultraviolet radiation or heat is applied to the liquid crystal composition to polymerize the monomer. (Item 17) A method of fabricating a liquid crystal display device as described in item 15 or 16, further comprising the step of forming a slit structure in the transparent electrode on at least one of the substrates. (Item 18) A method of fabricating a liquid crystal display device as described in any one of items 15 to 17, further comprising the step of forming, on at least one of the substrates, a protrusion protruding into the gap between the substrates. (Item 19) A liquid crystal display device fabricated by a method described in any one of items 15 to 18. The fabrication method for the liquid crystal display device according to the third aspect of the invention can be summarized as follows: (Item 20) A method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between two substrates each having a transparent electrode; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to liquid crystal molecules while, at the same time, controlling the direction in which the liquid crystal molecules tilt in the presence of an applied voltage, and wherein: light radiation for polymerizing the polymerizable monomer is performed in at least two steps. (Item 21) A method of fabricating a liquid crystal display device as described in item 20, wherein at least one of the plurality of light radiation steps is performed while applying a voltage to the liquid crystal layer. (Item 22) A method of fabricating a liquid crystal display device as described in item 20 or 21, wherein the plurality of light radiation steps are performed without applying a voltage, either before or after or both before and after the light radiation that is performed in the presence of an applied voltage. (Item 23) A method of fabricating a liquid crystal display device as described in any one of items 20 to 22, wherein the plurality of light radiation steps are respectively performed with different light intensities. (Item 24) A method of fabricating a liquid crystal display device as described in any one of items 20 to 23, wherein the light radiation that is performed in the presence of an applied voltage is performed with a light intensity of 50 mW/cm2 or higher. (Item 25) A method of fabricating a liquid crystal display device as described in any one of items 20 to 24, wherein the light radiation that is performed without applying a voltage is performed with a light intensity of 50 mW/cm2 or lower. (Item 26) A method of fabricating a liquid crystal display device as described in any one of items 20 to 25, wherein the polymerizable monomer is a liquid crystalline or non-liquid-crystalline monomer, and is polymerized by ultraviolet radiation. (Item 27) A method of fabricating a liquid crystal display device as described in any one of items 20 to 26, wherein the polymerizable monomer is bifunctional acrylate or a mixture of bifunctional acrylate and monofunctional acrylate. (Item 28) A liquid crystal display device fabricated by a method described in any one of items 20 to 27. The liquid crystal display device according to the fourth aspect of the invention can be summarized as follows: (Item 29) A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a plurality of injection ports for injecting therethrough the liquid crystal composition containing the polymerizable component are formed in one side of the liquid crystal display device, and spacing between the respective injection ports is not larger than one-fifth of the length of the side in which the injection ports are formed. (Item 30) A liquid crystal display device as described in item 29, wherein the injection ports are spaced away from a display edge by a distance not greater than two-fifths of the length of the side in which the injection ports are formed. (Item 31) A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a cell gap in a frame edge BM area is not larger than the cell gap of a display area. (Item 32) A liquid crystal display device as described in item 31, wherein the area where the cell gap is not larger than the cell gap of the display area is spaced away from a cell forming seal by a distance not greater than 0.5 mm. (Item 33) A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a main seal or an auxiliary seal is formed in a frame edge BM area to eliminate cell gap in the frame edge BM area. (Item 34) A liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein an auxiliary seal is formed so that a material whose concentration of the polymerizable material relative to liquid crystal is abnormal is guided into a BM area. (Item 35) A liquid crystal display device as described in any one of items 29 to 34, wherein the liquid crystal composition contains a non-liquid-crystal component or a component whose molecular weight and surface energy are different from those of a liquid-crystal component. The fabrication method for the liquid crystal display device according to the fifth aspect of the invention can be summarized as follows: (Item 36) A method of fabricating a liquid crystal display device, comprising: forming a common electrode and a color filter layer on a first substrate; constructing a second substrate from an array substrate on which are formed a gate bus line layer, a gate insulating film layer, a drain bus line layer, a protective film layer, and a pixel electrode layer; forming fine slits in the pixel electrode layer in such a direction that a pixel is divided by the slits into at least two sub-regions; forming on each of the two substrates a vertical alignment film for vertically aligning liquid crystal molecules; forming a liquid crystal layer by filling an n-type liquid crystal composition having a negative dielectric anisotropy into a gap between the two substrates, the liquid crystal composition containing an ultraviolet curable resin having a liquid crystal backbone; radiating ultraviolet light while applying to the liquid crystal molecules a voltage not smaller than a threshold value of the liquid crystal molecules, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage; and arranging two polarizers on top and bottom surfaces of the liquid crystal display device in a crossed Nicol configuration with the absorption axes thereof oriented at an angle of 45 degrees to the alignment directions of the liquid crystal molecules. (Item 37) A method of fabricating a liquid crystal display device as described in item 36, wherein the step of radiating the ultraviolet light to the liquid crystal composition injected between the two substrates is divided in two or more steps and performed by using ultraviolet light of different intensities. (Item 38) A method of fabricating a liquid crystal display device as described in item 36, wherein the step of radiating the ultraviolet light to the liquid crystal composition injected between the two substrates is divided in two steps consisting of the step of radiating the ultraviolet light while applying to the liquid crystal molecules a voltage not smaller than the threshold value of the liquid crystal molecules and the step of radiating the ultraviolet light without applying a voltage to the liquid crystal molecules. (Item 39) A method of fabricating a liquid crystal display device as described in item 36, wherein the step of radiating the ultraviolet light to the liquid crystal composition injected between the two substrates is divided in two steps and performed by applying respectively different voltages to the liquid crystal molecules. (Item 40) A method of fabricating a liquid crystal display device as described in item 36, wherein the step of radiating the ultraviolet light for polymerizing the ultraviolet polymerizable component contained in the liquid crystal composition injected between the two substrates is divided in two or more steps and performed by using a plurality of ultraviolet radiation units of different light intensities. (Item 41) A method of fabricating a liquid crystal display device as described in item 36, wherein the ultraviolet radiation to the liquid crystal composition injected between the two substrates is applied from the array substrate side. (Item 42) A method of fabricating a liquid crystal display device as described in item 36, wherein the second substrate is constructed from an array substrate on which the color filter layer is formed, the common electrode being formed on the first substrate, and the ultraviolet radiation, onto the liquid crystal composition injected between the two substrates, is applied from the first substrate side. (Item 43) A liquid crystal display device fabricated by a method described in any one of items 36 to 42. The liquid crystal display device according to the sixth aspect of the invention can be summarized as follows: (Item 44) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein any portion where cell thickness varies by 10% or more due to design constraints is located at a liquid crystal domain boundary. (Item 45) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a source electrode and a pixel electrode is formed at a liquid crystal domain boundary. (Item 46) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a Cs intermediate electrode and a pixel electrode is formed at a liquid crystal domain boundary. (Item 47) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one portion where cell thickness varies by 10% or more due to design constraints does not exist. (Item 48) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one contact hole is not formed in the same sub-region. (Item 49) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a pixel electrode, a source electrode, and a Cs intermediate electrode are connected by a single contact hole. (Item 50) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a metal electrode is added along a liquid crystal domain boundary within a display pixel. (Item 51) A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein an electrode having the same potential as a pixel electrode is not added in a slit portion of the pixel electrode within a display pixel. (Item 52) A liquid crystal display device as described in any one of items 44 to 51, wherein the liquid crystal layer is sandwiched between a substrate in which a color filter layer of red, blue, and green is formed on a TFT substrate, and a substrate on which a common electrode is formed. The fabrication method for the liquid crystal display device according to the fifth aspect of the invention can be summarized as follows: The fabrication method for the liquid crystal display device according to the seventh aspect of the invention can be summarized as follows: (Item 53) A method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between two substrates each having an electrode and an alignment film; and polymerizing the monomer by radiating ultraviolet light to the liquid crystal composition while applying a prescribed liquid crystal driving voltage between opposing electrodes, and wherein: after polymerizing the monomer, additional ultraviolet radiation is applied to the liquid crystal composition without applying the liquid crystal driving voltage or while applying a voltage of a magnitude that does not substantially drive the liquid crystal. (Item 54) A method of fabricating a liquid crystal display device as described in item 53, wherein the additional ultraviolet radiation is applied using ultraviolet light whose wavelength is different from that of the ultraviolet light used for the polymerization of the monomer before the application of the additional ultraviolet radiation. (Item 55) A method of fabricating a liquid crystal display device as described in item 53 or 54, wherein the ultraviolet light used in the additional ultraviolet radiation has a spectrum having a maximum energy peak at 310 to 380 nm. (Item 56) A method of fabricating a liquid crystal display device as described in item 55, wherein the ultraviolet light used in the additional ultraviolet radiation has a spectrum having a maximum energy peak at 350 to 380 nm. (Item 57) A method of fabricating a liquid crystal display device as described in item 55, wherein the ultraviolet light used in the additional ultraviolet radiation has a spectrum having a maximum energy peak at 310 to 340 nm. (Item 58) A method of fabricating a liquid crystal display device as described in any one of items 53 to 57, wherein the additional ultraviolet radiation is applied for 10 minutes or longer. (Item 59) A method of fabricating a liquid crystal display device as described in any one of items 53 to 58, wherein substrate surfaces are treated for vertical alignment in accordance with a vertical alignment mode, and liquid crystals in a non-display area also are substantially vertically aligned. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a liquid crystal display device to be used for television and other display apparatuses, to a method of fabricating the same and, more particularly, to a liquid crystal display device that uses a liquid crystal material containing a photosensitive material and a method of fabricating the same. 2. Description of the Related Art A liquid crystal display device is a display device that comprises a liquid crystal sealed between two opposing substrates and that uses electrical stimulus for optical switching by exploiting the electro-optical anisotropy of a liquid crystal. Utilizing the refractive index anisotropy that the liquid crystal possesses, the brightness of the light transmitted by the liquid crystal panel is controlled by applying a voltage to the liquid crystal and thereby reorienting the axis of the refractive index anisotropy. In such a liquid crystal display device, it is extremely important to control the alignment of liquid crystal molecules when no voltage is applied to the liquid crystal. If the initial alignment is not stable, when a voltage is applied to the liquid crystal, the liquid crystal molecules do not align in a predictable manner, resulting in an inability to control the refractive index. Various techniques have been developed to control the alignment of liquid crystal molecules, representative examples including a technique that controls the initially formed angle (pretilt angle) between the alignment film and the liquid crystal and a technique that controls the horizontal electric field formed between the bus line and the pixel electrode. The same can be said of a display device that uses a liquid crystal material containing a photosensitive material; specifically, in a liquid crystal display mode in which the initial alignment is controlled by radiation of light in the presence of an applied voltage, the voltage application method during the radiation becomes important. The reason is that, if the magnitude of the applied voltage differs, a change will occur in the initially formed pretilt angle, resulting in a change in transmittance characteristics. In connection with a first aspect of the invention, techniques called passive matrix driving and active matrix driving have usually been used to drive liquid crystals; nowadays, with an increasing demand for higher resolution, the active matrix display mode that uses thin-film transistors (TFTs) is the dominant liquid crystal display mode. In a liquid crystal display having such TFTs, when radiating light onto the liquid crystal while applying a voltage to it, it is usually practiced to expose the liquid crystal to light radiation while applying a TFT ON voltage to each gate bus line and a desired voltage to each data bus line, as shown in FIGS. 1 and 2 . However, when such a liquid crystal exposure method is employed, if there is a line defect due to a bus line break or short, as shown in FIG. 3 , the liquid crystal will be exposed to light when the liquid crystal in the affected area cannot be driven, and a pretilt angle different from that in other areas will be formed in this defect area, resulting in the problem that the brightness in this area differs from the brightness in other areas. Or, in the TFT channel ON state, a shift in the TFT threshold value can occur due to exposure to ultraviolet radiation, as shown in FIG. 4 , resulting in the problem that the region where the TFTs can be driven stably shifts from the desired region. On the other hand, in connection with a second aspect of the invention, displays using the TN mode have been the predominant type of active matrix liquid crystal display, but this type of display has had the shortcoming that the viewing angle is narrow. Nowadays, a technique called the MVA mode or a technique called the IPS mode is employed to achieve a wide viewing angle liquid crystal panel. In the IPS mode, liquid crystal molecules are switched in the horizontal plane by using comb-shaped electrodes, but a strong backlight is required because the comb-shaped electrodes significantly reduce the molecules are aligned vertically to the substrates, and the alignment of the liquid crystal molecules is controlled by the use of protrusions or slits formed in a transparent electrode (for example, an ITO electrode). The decrease in the effective numerical aperture due to the protrusions or slits used in MVA is not so large as that caused by the comb-electrodes in IPS, but compared with TN mode displays, the light transmittance of the liquid crystal panel is low, and it has not been possible to employ MVA for notebook computers that require low power consumption. When fine slits are formed in the ITO electrode, the liquid crystal molecules tilt parallel to the fine slits, but in two different directions. If the fine slits are sufficiently long, liquid crystal molecules located farther from a structure such as a bank that defines the direction in which the liquid crystal molecules tilt are caused to tilt randomly in two directions upon application of a voltage. However, the liquid crystal molecules located at the boundary between the liquid crystal molecules caused to tilt in different directions, cannot tilt in either direction, resulting in the formation of a dark area such as that shown in FIG. 29 . Further, in a structure where the liquid crystal molecules are caused to tilt in two different directions in order to improve viewing angle, if there are liquid crystal molecules that are caused to tilt in the opposite direction, as shown in FIG. 29 , the viewing angle characteristics degrade. In connection with a third aspect of the invention, in an LCD (MVA-LCD) in which an N-type liquid crystal is aligned vertically and in which, upon application of a voltage, the molecules of the liquid crystal are caused to tilt in a number of predefined directions by using alignment protrusions or electrode slits, the liquid crystal molecules are almost completely vertically aligned in the absence of an applied voltage, but are caused to tilt in the various predefined directions when a voltage is applied. The tilt directions of the liquid crystal molecules are controlled so that they always make an angle of 45° to the polarizer absorption axis, but the liquid crystal molecules as a continuum can tilt in a direction intermediate between them. Furthermore, areas where the tilt direction of the liquid crystal molecules is displaced from the predefined direction inevitably exist because of the effects of the horizontal electric field, etc. at the time of driving or irregularities in the structure. In normally black displays where the polarizers are arranged in a crossed Nicol configuration, this means that dark areas appear when the display is driven in the white display state, and the screen brightness thus decreases. To address this problem, in a liquid crystal display device constructed by sandwiching between two substrates a liquid crystal composition containing a photopolymerizable or thermally polymerizable component, there is employed a technique that polymerizes the polymerizable component while applying a voltage, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage. With this technique, however, if the polymerization is insufficient, image sticking can occur. This is believed to occur because the rigidity of the polymerized polymer is insufficient and deformation occurs due to the realignment of the liquid crystal molecules at the time of voltage application. On the other hand, to sufficiently polymerize the polymer, the duration of light radiation must be increased, but in that case, takt time at the time of volume production becomes a problem. In connection with a fourth aspect of the invention, conventional liquid crystal display devices predominantly use the TN mode in which horizontally aligned liquid crystal molecules are twisted between the top and bottom substrates, but gray-scale inversion occurs in the mid gray-scale range because the tilt angle of the liquid crystal differs depending on the viewing direction, that is, the viewing angle. To address this, a technique called the MVA mode has been proposed in which vertically aligned liquid crystal molecules are tilted symmetrically in opposite directions to compensate for the viewing angle. In this technique, alignment control members made of an insulating material are formed on electrodes to control the liquid crystal tilt directions. However, since the liquid crystal molecules tilt in 180° opposite directions on both sides of each alignment control member, a dark line is formed and transmittance decreases. To obtain sufficient transmittance, it is preferable to reduce the area occupied by the alignment control members by forming them spaced farther apart, but this would in turn slow the propagation speed of the tilt, resulting in a slow response speed. To address this, a technique has been proposed in which a liquid crystal composition containing a polymerizable component is sandwiched between substrates and, while applying a voltage, the polymerizable component is polymerized, thereby defining the tilt direction of the liquid crystal molecules. This achieves a faster response speed while retaining the transmittance. However, in the case of a liquid crystal display device in which the tilt direction of the liquid crystal molecules is defined by polymerizing the polymerizable component in the liquid crystal while applying a voltage, there arises the problem that display unevenness occurs after the polymerization of the polymerizable component, because of the separation of the liquid crystal and the polymerizable component which occurs when the liquid crystal material is injected at high speed at the initial stage of injection or when there is an abrupt change in speed near a frame edge. In connection with a fifth aspect of the invention, in a liquid crystal display device, it has traditionally been practiced to control the alignment direction of the vertically aligned panel by a TFT substrate having slits in pixel electrodes and a color filter substrate having insulating protrusions, and it has therefore been necessary to form the dielectric protrusions on one of the substrates. Fabrication of such a liquid crystal display device therefore has involved the problem that the number of processing steps increases. Furthermore, forming the protrusions within display pixels leads to the problem that the numerical aperture decreases, reducing the transmittance. In view of this, it has been proposed to control the alignment of the liquid crystal molecules by a polymerizable component added in the liquid crystal, in order to achieve multi-domains without using dielectric layer protrusions. That is, the liquid crystal to which the polymerizable component is added is injected into the panel and, while applying a voltage, the polymerizable component is polymerized, thereby controlling the alignment of the liquid crystal molecules. However, if the polymer composition that defines the alignment direction does not have a sufficient cross-linked structure, the polymer becomes flexible, and its restoring force weakens. If the polymer has such properties, then, when a voltage is applied to the liquid crystal to cause the liquid crystal molecules to tilt, and the liquid crystal is still held in that state, the pretilt angle of the liquid crystal does not return to its initial state even after the applied voltage is removed. This means that the voltage-transmittance characteristic has changed, and this defect manifests itself as a pattern image sticking. In connection with a sixth aspect of the invention, in an MVA-LCD in which liquid crystals having a negative dielectric anisotropy are vertically aligned, and in which the alignment of the liquid crystal in the presence of an applied voltage is controlled in a number of predefined directions, without using a rubbing treatment but by utilizing the banks or slits formed on the substrates, the LCD provides excellent viewing angle characteristics compared with conventional TN mode LCDs, but there is a disadvantage that white brightness is low and the display is therefore relatively dark. The major reason is that portions above the banks or slits correspond to the boundaries across which the liquid crystal alignment changes, and these portions appear optically dark, reducing the transmittance of white. To improve this, the spacing between the banks or slits should be made sufficiently wide, but in that case, as the number of banks or slits for controlling the liquid crystal alignment decreases, it takes time until the alignment stabilizes, thus slowing the response speed. To obtain a brighter, faster response MVA panel by alleviating the above deficiency, it is effective to use a technique in which a liquid crystal composition containing a polymerizable component is sandwiched between substrates and, while applying a voltage, the polymerizable component is polymerized, thereby defining the tilt direction of the liquid crystal molecules. For the polymerizable component, a monomer material that polymerizes by ultraviolet radiation or heat is usually used. It has, however, been found that this method has a number of problems associated with display unevenness. That is, as this method is a rubbing-less method, if there occurs even a slight change in the structure or in electric lines of force, the liquid crystal molecules may not align in the desired direction. As a result, there are cases where a contact hole or the like formed outside the display area disrupts the alignment of the liquid crystal molecules and the disruption affects the alignment of the liquid crystal molecules within the display area, resulting in the formation of an abnormal domain and causing the alignment to be held in that state. Furthermore, if structures that cause such disruptions in liquid crystal molecular alignment are located in the same alignment sub-region, abnormal domains formed from the respective structures are concatenated, forming a larger abnormal domain. This causes the liquid crystal molecules outside and inside the display area to be aligned in directions other than the desired directions, and the polymerizable component is polymerized in that state, resulting in such problems as reduced brightness, slower response speed, and display unevenness. FIG. 44 is a plan view showing a pixel in the prior art. In the pixel shown here, contact holes that cause variations in cell thickness are not located at liquid crystal domain boundaries, and two contact holes are located within the same alignment sub-region. As a result, an abnormal domain is formed in such a manner as to connect the two contact holes and, with the alignment held in this state, the polymerizable component is polymerized, resulting in display performance degradations such as reduced brightness, slower response speed, and display unevenness. Further, when a metal electrode such as a source electrode or a Cs intermediate electrode is extended into the display pixel, there occurs the problem of reduced numerical aperture, and hence, reduced brightness. Moreover, if an electrode with the same potential as the pixel electrode is extended into the display pixel, this also causes reduced brightness, slower response speed, and display unevenness. In connection with a seventh aspect of the invention, while conducting studies on the technique in which a liquid crystal composition containing a polymerizable component is sandwiched between substrates and, while applying a voltage, the polymerizable component is polymerized, thereby defining the tilt direction of the liquid crystal molecules, the inventor et al. encountered the problem that when the same pattern was displayed for a certain length of time, image sticking occurred in the portion where the pattern was displayed. This is believed to occur because the polymerization is insufficient and the polymer deforms. On the other hand, to sufficiently polymerize the polymer, the duration of light radiation or heating must be increased, but in that case, tact time at the time of volume production becomes a problem. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention aims to solve the above-enumerated problems of the prior art and to provide a method of fabricating a liquid crystal display device which, during fabrication of the liquid crystal display device, controls the alignment of liquid crystal molecules when radiating light onto a liquid crystal composition containing a photosensitive material, and thereby achieves substantially uniform alignment of the liquid crystal molecules and ensures stable operation. The invention also aims to provide such a liquid crystal display device. To solve the above-enumerated problems, the first aspect of the invention provides methods based on the following three major concepts. 1. Avoid the effects of wiring defects by driving the liquid crystal by applying an AC voltage and using an electrical capacitance. 2. Avoid the effects of wiring defects by holding the wiring lines and electrodes on the second substrate at the same potential. 3. Avoid the effects of wiring defects while screening TFT channel portions from light. More specifically, based on the first concept, the first aspect of the invention provides (1) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light to the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying AC voltages to the common electrode and the Cs bus line. Based on the second concept, the invention provides (2) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; insulating the common electrode from the three bus lines, or connecting the common electrode to the three bus lines via high resistance; and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the three bus lines (the gate bus line, the data bus line, and the Cs bus line) formed on the second substrate, or (3) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with at least one of the data bus and gate bus lines; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and the four bus lines (the gate bus line, the data bus line, the Cs bus line, and the repair line) formed on the second substrate, or (4) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; and connecting the common electrode, via high resistances, to the three bus lines (the gate bus line, the data bus line, and the Cs bus line,) formed on the second substrate, and radiating light to the liquid crystal layer while applying a DC voltage between the common electrode and the pixel electrode by applying a DC voltage between the common electrode and at least one of the bus lines. Based on the third concept, the invention provides (5) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, and a Cs bus line that forms an electrical capacitance to the pixel electrode; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; electrically connecting adjacent data bus lines at both ends thereof; and radiating light to the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line, or (6) a method of fabricating a liquid crystal display device, comprising: forming on a first substrate a common electrode for applying a voltage over an entire surface of the substrate; forming on a second substrate a gate bus line and a data bus line arranged in a matrix array, a thin-film transistor located at an intersection of the two bus lines, a pixel electrode connecting to the thin-film transistor, a Cs bus line that forms an electrical capacitance to the pixel electrode, and a repair line intersecting with the data bus line; forming a CF resin or a light blocking pattern on a channel portion of the thin-film transistor; forming a liquid crystal layer by filling a liquid crystal composition, containing a photosensitive material, into a gap between the first substrate and the second substrate; forming an electrical capacitance by the common electrode and the pixel electrode by sandwiching the liquid crystal layer therebetween; connecting at least one data bus line with at least one repair line by laser radiation or another method; and radiating light to the liquid crystal layer while applying an AC voltage between the common electrode and the pixel electrode by applying a transistor ON voltage to the gate bus line and an AC voltage between the common electrode and the data bus line and repair line (the repair line is at the same potential as the data bus line). In the second aspect of the invention, there is provided (7) a method of fabricating a vertical alignment liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition into a gap between two substrates each having a transparent electrode and an alignment control film for causing liquid crystal molecules to align vertically, the liquid crystal composition having a negative dielectric anisotropy and containing a polymerizable monomer; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to the liquid crystal molecules, and wherein: before polymerizing the monomer, a constant voltage not smaller than a threshold voltage but not greater than a saturation voltage is applied between the opposing transparent electrodes for a predetermined period of time, and thereafter, the voltage is changed to a prescribed voltage and, while maintaining the prescribed voltage, ultraviolet radiation or heat is applied to the liquid crystal composition to polymerize the monomer. That is, when polymerizing the polymerizable monomer, a voltage slightly higher than the threshold voltage is applied and, after the liquid crystal molecules are tilted in the right direction, the voltage is raised to a higher level; then, while maintaining the voltage at the higher level, the polymerizable monomer is polymerized. In the third aspect of the invention, there is provided (8) a method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between two substrates each having a transparent electrode; and polymerizing the monomer while applying a voltage between opposing transparent electrodes, and thereby providing a pretilt angle to liquid crystal molecules while, at the same time, controlling the direction in which the liquid crystal molecules tilt in the presence of an applied voltage, and wherein: light radiation for polymerizing the polymerizable monomer is performed in at least two steps. In the fourth aspect of the invention, there is provided (9) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is photopolymerized or thermally polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a plurality of injection ports for injecting therethrough the liquid crystal composition containing the polymerizable component are formed in one side of the liquid crystal display device, and spacing between the respective injection ports is not larger than one-fifth of the length of the side in which the injection ports are formed, or (10) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a cell gap in a frame edge BM area is not larger than the cell gap of a display area, or (11) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein a main seal or an auxiliary seal is formed in a frame edge BM area to eliminate a cell gap in the frame edge BM area, or (12) a liquid crystal display device in which a liquid crystal composition containing a photopolymerizable or thermally polymerizable component is sandwiched between substrates and the polymerizable component is polymerized while applying a voltage, thereby defining the direction in which liquid crystal molecules tilt in the presence of an applied voltage, wherein an auxiliary seal is formed so that a material whose concentration of the polymerizable material relative to liquid crystal is abnormal is guided into a BM area. In the fifth aspect of the invention, there is provided (13) a method of fabricating a liquid crystal display device, comprising: forming a common electrode and a color filter layer on a first substrate; constructing a second substrate from an array substrate on which are formed a gate bus line layer, a gate insulating film layer, a drain bus line layer, a protective film layer, and a pixel electrode layer; forming fine slits in the pixel electrode layer in such a direction that a pixel is divided by the slits into at least two sub-regions; forming on each of the two substrates a vertical. alignment film for vertically aligning liquid crystal molecules; forming a liquid crystal layer by filling an n-type liquid crystal composition having a negative dielectric anisotropy into a gap between the two substrates, the liquid crystal composition containing an ultraviolet curable resin having a liquid crystal backbone; radiating ultraviolet light while applying to the liquid crystal molecules a voltage not smaller than a threshold value of the liquid crystal molecules, thereby defining the direction in which the liquid crystal molecules tilt in the presence of an applied voltage; and arranging two polarizers on top and bottom surfaces of the liquid crystal display device in a crossed Nicol configuration with the absorption axes thereof oriented at an angle of 45 degrees to the alignment directions of the liquid crystal molecules. In the sixth aspect of the invention, there is provided (14) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein any portion where cell thickness varies by 10% or more due to design constraints is located at a liquid crystal domain boundary, or (15) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a source electrode and a pixel electrode is formed at a liquid crystal domain boundary, or (16) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a contact hole that connects between a Cs intermediate electrode and a pixel electrode is formed at a liquid crystal domain boundary, or (17) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one portion where cell thickness varies by 10% or more due to design constraints does not exist, or (18) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, and liquid crystal alignment is divided between two or more sub-regions, wherein more than one contact hole is not formed in the same sub-region, or (19) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a pixel electrode, a source electrode, and a Cs intermediate electrode are connected by a single contact hole, or (20) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein a metal electrode is wired along a liquid crystal domain boundary within a display pixel, or (21) a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates having electrodes, and a pretilt angle of liquid crystal molecules and a tilt direction thereof in the presence of an applied voltage are controlled by using a polymer that polymerizes by heat or light radiation, wherein an electrode having the same potential as a pixel electrode is not wired in a slit portion of the pixel electrode within a display pixel. In the seventh aspect of the invention, there is provided a (22) a method of fabricating a liquid crystal display device, comprising: forming a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer into a gap between a pair of substrates having electrodes; and polymerizing the monomer by radiating ultraviolet light to the liquid crystal composition while applying a prescribed liquid crystal driving voltage between opposing electrodes, and wherein: after polymerizing the monomer, additional ultraviolet radiation is applied to the liquid crystal composition without applying the liquid crystal driving voltage or while applying a voltage of a magnitude that does not substantially drive the liquid crystal. | 20040716 | 20081111 | 20050203 | 98141.0 | 1 | DUDEK, JAMES A | LIQUID CRYSTAL DISPLAY DEVICE AND METHOD OF FABRICATING THE SAME | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,893,812 | ACCEPTED | Method for installing paving blocks | A method of installing paving blocks comprises preparing an area to be paved to a desired grade. A preformed, load-bearing sheet of material, e.g., extruded polystyrene, is placed on the prepared area. Paving blocks are then laid in a desired pattern on the sheet of material. | 1. A method of installing paving blocks comprising preparing an area to be paved to a desired grade, placing a preformed, load-bearing sheet of material on the prepared area without the use of an underlying support substructure, and laying paving blocks in a desired pattern on the sheet of material. 2. A method as in claim 1, further comprising prior to preparing the area to paved, outlining a perimeter of the area to be paved. 3. A method as in claim 1, further comprising prior to preparing the area to be paved, staking the area to be paved and marking the desired grade elevations. 4. A method as in claim 1 wherein the preformed, load-bearing sheet of material is a foam sheet. 5. A method as in claim 4 wherein the foam sheet has a grid marked thereon. 6. A method as in claim 4 wherein the foam sheet comprises extruded polystyrene. 7. A method as in claim 1, further comprising marking a grid on the sheet prior to laying paving blocks. 8. A method as in claim 1, further comprising after laying paving blocks, placing a joint-filling material in spaces between the paving blocks. 9. A method as in claim 8 wherein the joint-filling material is sand. 10. A method as in claim 9 wherein the sand is stabilized sand. 11. A method as in claim 9 wherein the sand is polymeric sand. 12. A method as in claim 9, further comprising after placing the sand in spaces between the paving blocks, spraying liquid over the blocks to soak the sand. 13. A method as in claim 12 wherein the liquid is water. 14. A method as in claim 1, further comprising after placing the load-bearing sheet, laying an edging material. 15. A method as in claim 1, further comprising after placing the load-bearing sheet, laying a soldier course of paving blocks on top of the sheet. 16. A method as in claim 15, further comprising placing an adhesive between a plurality of the paving blocks comprising the soldier course. 17. A method as in claim 16 wherein the adhesive is a masonry adhesive. | FIELD OF INVENTION This invention relates to installing dry-laid masonry paving blocks, e.g., pavers, to create a path, driveway, or patio. BACKGROUND OF THE INVENTION The use of concrete paving blocks (“pavers”) in landscaping is common. Pavers are widely used for driveways, sidewalks, patios, garden paths, and even porch floors. Individually, they are lightweight and durable. Pavers withstand abuse by flexing, rather than cracking, under pressure. They're ideal for regions that go through freeze/thaw cycles, as individual pavers absorb heaving and movement without cracking. Pavers also provide for easy repair, as replacing an individual paver or small area of pavers is easier and less costly than replacing a large concrete slab. Conventional methods of installing masonry paving blocks (“pavers”) require the installer to outline the perimeter of the area being paved. Sod and/or soil are then removed to excavate the area. The desired grade is established and the area can be staked as necessary to ensure the proper elevation of the paved surface. A subbase, e.g., Class 5 crushed limestone, is placed over the excavated area. The subbase is desirably then tamped (e.g., with a vibrator) to tightly compact the subbase. Edging is installed at the perimeter of the area to be paved. The edging provides lateral (horizontal) resistance to the pavement, thereby maintaining the interlock and load spreading capabilities of the units. A variety of different types of edging are commonly used, including wood, steel, aluminum, PVC, and concrete. Sand is then spread over the subbase and leveled by screeding to form a sand base or layer. The pavers can then be laid in a desired pattern and tamped with a vibrator to lock the pavers into the sand and help even the surface. Additional sand is then spread over the pavers and swept or otherwise driven into the joints between the pavers to lock the pavers together and fill voids. A water sealer can be applied over the completed paved area if desired. It is apparent that these methods can require some technical knowledge or expertise and are generally tedious and time-consuming. Consequently, a professional often performs the installation. In many cases, however, the homeowner or landowner desires to perform the installation as a “do-it-yourself” project. This not only eliminates the cost of hiring a professional, thereby significantly reducing the total cost of the project, but also provides a sense of satisfaction and accomplishment to the homeowner or landowner. Therefore, there is a need to simplify methods of installing pavers to permit installation by non-professionals with limited or no technical knowledge. The need also remains for simplified systems and methods of installing pavers that are both cost and time-efficient to both professional and non-professional installers without sacrificing the structural integrity of the installation. SUMMARY OF THE INVENTION According to one aspect of the invention, a method of installing paving blocks comprises preparing an area to be paved to a desired grade, placing a preformed, load-bearing sheet of material on the prepared area, and laying paving blocks in a desired pattern on the sheet of material. In one embodiment, the preformed, load-bearing sheet of material is a foam sheet. The foam sheet may have a grid marked thereon. In one embodiment, the foam sheet is extruded polystyrene. According to another aspect of the invention, the area to be paved is outlined prior to preparing the area. According to another aspect of the invention, the area to be paved is staked and the desired grade elevations are marked prior to preparing the area. According to another aspect of the invention, a joint-filling material is placed in spaces between the paving blocks. In one embodiment, the joint-filling material is sand. The sand may be a polymeric or stabilized sand requiring activation to harden the sand. According to another aspect of the invention, liquid is sprayed over the blocks to soak and thereby activate the sand. In one embodiment, the liquid is water. According to another aspect of the invention, an edging material is laid after placing the load-bearing sheet to restrain lateral (horizontal) movement of the pavers. A soldier course of paving blocks is then placed on top of the sheet. In an alternative embodiment, an adhesive is placed between a plurality of the paving blocks comprising the soldier course to restrain lateral (horizontal) movement of the pavers, eliminating the need for an edging material. In one embodiment, the adhesive is a masonry adhesive. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the marking of an area to be paved. FIG. 2 is a perspective view illustrating the excavation of soil from the area to be paved. FIG. 3 is a perspective view illustrating the marking of a desired grade for an area to be paved. FIG. 4 is a perspective view illustrating the smoothing and leveling of the soil along a marked grade to prepare the area to be paved. FIG. 5 is a side sectional view illustrating placement of a foam base and a series of paving blocks to establish a paved surface that is flush with the existing grade. FIG. 6 is a side sectional view illustrating placement of a foam base and a series of paving blocks to establish a paved surface that is raised or elevated with respect to the existing grade. FIG. 7 is a perspective view illustrating the marking of a grid on a foam sheet base. FIG. 8A is a perspective view illustrating the placement of a series of 4 ft.×8 ft. foam sheets to construct a pathway. FIG. 8B is a perspective view illustrating the placement of a series of 4 ft.×4 ft. and 4 ft.×8 ft. foam sheets to construct a 12 ft.×12 ft. paved surface. FIG. 8C is a perspective view illustrating the placement of a series of 4 ft.×4 ft. and 4 ft.×8 ft. foam sheets to construct a 12 ft.×16 ft. paved surface. FIG. 9 is a perspective view illustrating the placement of a series of pavers on a foam sheet and illustrating the use of a mechanical edging barrier to restrain lateral (horizontal) movement of the pavers. FIG. 10 is a view similar to FIG. 9 and illustrating the use of a masonry adhesive to restrain lateral (horizontal) movement of the pavers. FIG. 11 is a perspective view illustrating the sweeping of stabilized or polymeric sand between the pavers to fill the joints between the pavers. FIG. 12 is a perspective view illustrating the application of water to the paved surface to harden the sand. DESCRIPTION OF THE PREFERRED EMBODIMENT Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention that may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. A method of installing paving blocks (“pavers”) will be described with reference to the figures, in which like reference numbers denote like parts. In the illustrated embodiment, the pavers take the form of interlocking paving stones. However, it is contemplated that a variety of different types and sizes of pavers may be used, e.g., concrete or natural stone patio shapes in square, rectangle, rhombus or other geometric shapes of generally uniform thickness and dry set with close joints. As illustrated in FIG. 1, an area of ground 10 is outlined to define the area 12 to be paved. To assist in outlining the area the area 12 to be paved, the center point 14 of the area 12 to be paved can be marked to serve as a reference point, e.g., with a post 16. The area 12 to be paved is then measured, e.g., with a tape measure 18 or other suitable measuring device. Curved areas may be marked with a hose 20 or other suitable flexible device. Straight areas may be marked with a board 22 (e.g., 2 in.×4 in.) or other suitable device. The ground 10 is marked until the perimeter of the area 12 to be paved is outlined in its entirety. Desirably, the outline of the area 12 to be paved is then marked, e.g., with spray-paint, to act as a guide for excavating (not shown). It may be desirable to make an outline that is slightly larger than the area 12 to be paved, e.g., 8 in. from the perimeter of the area 12 to be paved, to provide an enlarged working area. The enlarged working area prevents grass from getting in the way of any guide strings or other markers that will be set up. As FIG. 2 shows, sod 24 and/or soil 26 are removed to prepare the area 12 to be paved. With reference now to FIGS. 3 and 4, the installer can then stake the area and establish grade elevations to ensure the proper elevation of the paved surface. It is usually desirable that the paved surface has a slight slope (e.g., 1 in. for every 4 to 8 ft.) for proper drainage. For example, as seen in FIG. 3, a level 28 and a 2 in.×4 in. or other suitable board 30 may be used to mark the grade by placing a mark 32 on posts 34 in the ground 10. Once the grade is marked, string or rope 36 can be extended between the marks 32 to indicate the grade, as shown in FIG. 4. Once the grade is marked, excavation may be completed. If it is desired that the paved surface when completed be flush with the existing grade, it is necessary for the installer to excavate to the proper depth. For example, and as FIG. 5 shows, to accommodate a standard 2-inch deep paver 38 on top of a two-inch base 40, it would be necessary to excavate the soil 26 to a depth of 4 inches. In the illustrated embodiment, the base 40 is a 2 inch deep foam sheet, as will be described in detail later. If it is desired that the paved surface be raised above the existing grade, the installer need only remove the sod 24 from the area, as seen in FIG. 6. With reference again to FIG. 4, the soil 26 is scraped flat so as to be generally level and smooth. A preformed, load-bearing sheet of material 40 or series of sheets 40 are placed over the soil base to cover the area 12 to be paved. The sheet 40 can be formed of any suitable material with sufficient insulating and bearing strength capabilities and providing sufficient density for the intended use (i.e., patio, vehicular traffic, etc.). The sheet 40 is desirably formed of an insulating or board-type foam material that is inexpensive, easy to use, durable, and widely available, e.g., polyisocyanurate, extruded polystyrene, or other similar materials. In a preferred embodiment, the foam sheet 40 is made of extruded polystyrene, e.g., STYROFOAM® foam available from the Dow Chemical Company. The foam sheet 40 permits load transfer from the pavers 38 to and across the foam sheet 40. The foam sheet 40 also eliminates the need for a compacted subbase, resulting in both cost and time savings. The foam base 40 also resists growth of grass and incursion of insects between the pavers 38. FIG. 7 illustrates the preparation of the foam sheet 40 by placement of a grid 42 marking on the sheet 40. The grid 42 serves as a guideline for proper placement of the pavers 38, allowing for quick placement of the pavers 38 and thus providing additional timesaving. For example, if standard 4 inch×8 inch pavers 38 are used, chalk lines may be snapped using a chalk line marker 44 in an 8 inch square grid pattern for the best paver 38 alignment and proper 1/16 inch joint gap between the pavers 38. The grid 42 is easily customized to accommodate any size or configuration of paver 38 as well as a specific design plan. The grid 42 may be preformed or pre-marked on the sheet 40 by the manufacturer or marked by the installer at the time of use to customize the grid 42. The foam sheet 40 is then laid on the prepared, undisturbed soil 26. In most cases, a series of foam sheets 40 will be required to fully cover and prepare the area 12 to be paved. It is contemplated that the sheets 40 may be laid in a variety of arrangements to accommodate specific design plans. The sheets 40 may also be cut or formed to a square, rectangular, or circular configuration or to any other desired configuration as necessary. For example, a series of 4 ft.×8 ft. sheets 40A may be arranged to construct a pathway (FIG. 8A), or a series of 4 ft.×8 ft. sheets 40A and 4 ft.×4 ft. sheets 40B may be arranged to construct a 12 ft.×12 ft. patio (FIG. 8B) or a 12 ft.×16 ft. patio (FIG. 8C). It is apparent that the configuration and placement of sheets 40 may be varied to accommodate virtually any design plan. In a preferred embodiment, the foam sheets 40 have a thickness or depth of two inches. However, it is to be understood that sheets 40 having a greater or lesser depth can be used to accommodate specific needs. To ensure long-term stability of the paved surface, it is necessary to restrain the pavers 38 around the perimeter edge of the paved surface. The perimeter restraint provides lateral (horizontal) resistance to movement of the pavers 38, thereby maintaining the interlock and load spreading capabilities of the paver units 38. As shown in FIG. 9, perimeter restraint may be accomplished by the use of a mechanical barrier or edging 46, as is widely known in the art. Wood, steel, aluminum, PVC, and concrete are suitable materials for the edging 46, which may be secured by a pin 48 or other suitable securing means. As FIG. 10 shows, perimeter restraint may alternatively be accomplished by the application of a masonry adhesive 50. The adhesive 50 may be applied between adjacent pavers 38 forming a perimeter or soldier course 52 to glue the soldier course pavers 38 side by side. If desired, the adhesive 50 may also be applied between pavers 38 forming the soldier course 52 and pavers 38 forming an adjacent interior course 53, as also shown in FIG. 10. Suitable adhesives 50 include PAVER BOND™ masonry adhesive available from Surebond, Inc. and TECHNI-SEAL® masonry adhesive available from Techni-Seal Chemicals, Inc. It is preferable that sufficient space or gaps be left between application points of the adhesive 50 so as to permit sand or other joint-filling material to be placed in the joints 56 between the pavers 38, as will be described in greater detail later. The pavers 38 are laid on the foam sheet 40 in a desired pattern, as also shown in FIGS. 9 and 10. As previously noted, the foam sheet 40 permits load transfer of the pavers 38 to and across the foam sheet 40. The grid 42 may be used to assist in proper placement of pavers 38 in a wide variety of patterns, e.g., running bond, basket weave, or herringbone. The grid 42 also permits the installer to begin installation with the soldier course 52 or with an inside course as desired to accommodate specific needs. After laying the pavers 38 in the desired pattern, the installer sweeps or otherwise places sand 54 into the joints 56 between the pavers 38, as FIG. 11 illustrates. The excess sand 54 is then removed. The sand 54 is preferably a stabilized sand, e.g., TECHNI-SEAL® polymeric sand available from Techni-Seal Chemicals, Inc. As seen in FIG. 12, the surface is then sprayed with water or other suitable liquid to soak the sand 54. The water activates the polymer, causing the sand 54 to harden. The hardened sand 54 provides long-term stability to the finished surface and resists incursion of insects between the pavers 38. The hardened sand 54 also serves to increase water runoff, further helping to maintain long-term stability. The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The use of concrete paving blocks (“pavers”) in landscaping is common. Pavers are widely used for driveways, sidewalks, patios, garden paths, and even porch floors. Individually, they are lightweight and durable. Pavers withstand abuse by flexing, rather than cracking, under pressure. They're ideal for regions that go through freeze/thaw cycles, as individual pavers absorb heaving and movement without cracking. Pavers also provide for easy repair, as replacing an individual paver or small area of pavers is easier and less costly than replacing a large concrete slab. Conventional methods of installing masonry paving blocks (“pavers”) require the installer to outline the perimeter of the area being paved. Sod and/or soil are then removed to excavate the area. The desired grade is established and the area can be staked as necessary to ensure the proper elevation of the paved surface. A subbase, e.g., Class 5 crushed limestone, is placed over the excavated area. The subbase is desirably then tamped (e.g., with a vibrator) to tightly compact the subbase. Edging is installed at the perimeter of the area to be paved. The edging provides lateral (horizontal) resistance to the pavement, thereby maintaining the interlock and load spreading capabilities of the units. A variety of different types of edging are commonly used, including wood, steel, aluminum, PVC, and concrete. Sand is then spread over the subbase and leveled by screeding to form a sand base or layer. The pavers can then be laid in a desired pattern and tamped with a vibrator to lock the pavers into the sand and help even the surface. Additional sand is then spread over the pavers and swept or otherwise driven into the joints between the pavers to lock the pavers together and fill voids. A water sealer can be applied over the completed paved area if desired. It is apparent that these methods can require some technical knowledge or expertise and are generally tedious and time-consuming. Consequently, a professional often performs the installation. In many cases, however, the homeowner or landowner desires to perform the installation as a “do-it-yourself” project. This not only eliminates the cost of hiring a professional, thereby significantly reducing the total cost of the project, but also provides a sense of satisfaction and accomplishment to the homeowner or landowner. Therefore, there is a need to simplify methods of installing pavers to permit installation by non-professionals with limited or no technical knowledge. The need also remains for simplified systems and methods of installing pavers that are both cost and time-efficient to both professional and non-professional installers without sacrificing the structural integrity of the installation. | <SOH> SUMMARY OF THE INVENTION <EOH>According to one aspect of the invention, a method of installing paving blocks comprises preparing an area to be paved to a desired grade, placing a preformed, load-bearing sheet of material on the prepared area, and laying paving blocks in a desired pattern on the sheet of material. In one embodiment, the preformed, load-bearing sheet of material is a foam sheet. The foam sheet may have a grid marked thereon. In one embodiment, the foam sheet is extruded polystyrene. According to another aspect of the invention, the area to be paved is outlined prior to preparing the area. According to another aspect of the invention, the area to be paved is staked and the desired grade elevations are marked prior to preparing the area. According to another aspect of the invention, a joint-filling material is placed in spaces between the paving blocks. In one embodiment, the joint-filling material is sand. The sand may be a polymeric or stabilized sand requiring activation to harden the sand. According to another aspect of the invention, liquid is sprayed over the blocks to soak and thereby activate the sand. In one embodiment, the liquid is water. According to another aspect of the invention, an edging material is laid after placing the load-bearing sheet to restrain lateral (horizontal) movement of the pavers. A soldier course of paving blocks is then placed on top of the sheet. In an alternative embodiment, an adhesive is placed between a plurality of the paving blocks comprising the soldier course to restrain lateral (horizontal) movement of the pavers, eliminating the need for an edging material. In one embodiment, the adhesive is a masonry adhesive. | 20040719 | 20070717 | 20060119 | 98298.0 | E01C500 | 1 | ADDIE, RAYMOND W | METHOD FOR INSTALLING PAVING BLOCKS | UNDISCOUNTED | 0 | ACCEPTED | E01C | 2,004 |
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10,894,029 | ACCEPTED | Method and apparatus for producing wood shavings | A heavy flywheel disc having a radially spaced apart array of pockets in which are mounted knives. Short logs, which have been de-barked, are fed in with their long axis parallel to the face of the flywheel. A hydraulic ram translates the logs sideways into the plane containing the rotating knives. The use of the hydraulic ram provides for a variable infeed speed to obtain the particular thickness of shavings which provides in the end commercially desirable shavings for use, for example, in horse stables. The knives have notched cutting edges. The notches limit the width of each shaving to create strands which are for example ¾ inches wide. The strands are then chopped in an automated chopping device such as a forage harvester to produce shavings. | 1. A device for producing shavings from woodpieces comprising: an infeed for translating woodpieces in a direction of flow from an upstream loading position to a downstream shaving position, wherein the woodpieces are oriented on the infeed transversely relative to the direction of flow, a flywheel rotatably mounted transversely across said downstream shaving position, said flywheel having a radially spaced apart array of apertures formed therein, radially spaced around an axis of rotation of said flywheel, a radially spaced apart array of elongate slicing knives mounted to said flywheel, each knife of said array of elongate slicing knives having a cutting edge elevated and inclined at a cutting angle relative to an upstream face of said flywheel so as to slice into the woodpieces when a woodpiece is pressed against said upstream face and said flywheel rotated so as to bring sequentially each said cutting edge into slicing engagement with the woodpiece, means for selectively translating the woodpieces downstream into said slicing engagement, wherein each said cutting edge has a spaced apart array of slits formed therein, spaced apart by a distance corresponding to a desired width dimension of a shaving-strand formed by said slicing engagement, wherein said slits are formed so as to extend perpendicularly into said each knife from said each cutting edge without any scoring protrusion protruding therefrom, a means cooperating with said flywheel for cutting the strands formed by said slicing engagement into shavings. 2. The device of claim 1 wherein said means cooperating with said flywheel for cutting into shavings the strands formed by said slicing engagement includes a device having at least one knife for chopping the strands. 3. The device of claim 2 wherein said device having at least one knife includes a gravity-feed hopper for collecting the strands downstream of said flywheel and for feeding the strands to the at least one knife. 4. The device of claim 3 further comprising a conveyor for conveying the strands from said flywheel into said hopper, and a pair of counter-rotating rolls mounted at the downstream end of said conveyor for pressing the strands between said pair of rolls before the strands fall into said hopper. 5. The device of claim 4 wherein one roll of said pair of rolls has a resilient outer surface. 6. The device of claim 2 wherein said means cooperating with said flywheel includes a forage harvester. 7. The device of claim 1 wherein said apertures are elongate pockets and wherein said cutting angle is substantially 30 degrees, so that the strands as they are sliced from the woodpiece by said slicing engagement pass through a corresponding pocket of said pockets and exit from a downstream face of said flywheel opposite said upstream face of said flywheel. 8. The device of claim 1 wherein said axis of rotation of said flywheel is substantially parallel to said direction of flow. 9. The device of claim 8 wherein said axis of rotation bisects said infeed at said downstream position, and wherein said apertures and corresponding said knives extend substantially from said axis of rotation radially outwardly. 10. The device of claim 9 wherein said infeed at said downstream position includes a rigid housing for storing a queue of parallel woodpieces, said housing having an upstream infeed aperture for receiving the woodpieces in the direction of flow, and a downstream outfeed aperture adjacent said upstream face of said flywheel and generally laterally centered on said axis of rotation, and wherein said means for selectively pressing the woodpieces into said slicing engagement includes a selectively actuable actuator for urging a downstream-most woodpiece in the queue of woodpieces through said outfeed aperture into said slicing engagement with said knives on said flywheel. 11. The device of claim 10 wherein said actuator is selectively actuable to controllably vary a compressive force and forward speed exerted by said actuator against the downstream-most woodpiece. | FIELD OF THE INVENTION This invention relates to the field of wood shaving and chipping machines. BACKGROUND OF THE INVENTION Devices for producing wood shavings from pieces of wood have long been known in art. By way of example, Canadian Patent No. 557,559 which issued to Steiner et al. on May 20, 1958, for an invention entitled Production of Shavings from Pieces of Wood discloses that it was then known to produce shavings for the manufacture of wood particle panels and other similar composite products. Pieces of wood waste are disintegrated on rotary-disk type shredding machines into shavings having pre-determined and properly chosen properties and dimensions, particularly shavings of a flat and pliably thin shape. Such rotary-disk machines include a rotating disk equipped with a number of blades whose edges extend along respective radii of the disk. Pieces of a wood of a given length are placed into a feed box which is traversed against the rotating blades. The shavings may be sub-divided by the use of scoring knives rotating together with and ahead of the cutter blades mounted on the rotating-disk. The blade-carrying disk extends in a vertical plane and has a horizontal shaft. The feed box is pressed and moved along with the woodpieces on a horizontal path towards the blades. Other prior art such as Canadian Patent Application No. 2,132,876 filed by Rice and published Sep. 30, 1993, entitled Apparatus and Method for Making Wood Curls discloses a mechanized disk flaker for producing curled food flakes. The disk flaker includes a rotatable disk plate having one or more cutting knives mounted to the disk plate so as to provide a slight rake angle between the tool face and a plane perpendicular to the direction of tool travel. The disk flaker includes rotatable and removable knife holders and also includes the use of scoring knives. In the prior art, applicant is also aware of Canadian Patent No. 991,833 which issued to Schaefer on Jun. 29, 1976, for A Knife for a Wood Shaving Machine. Schaefer discloses that the use of scoring knives may be replaced by the use scoring protrusions formed on the cutting edges of the knives used to produce wood shavings. In particular, Schaefer discloses the use of a bent-out cutting portion which results in a scoring edge, or a U or V-shaped bead which produces a scoring beak located outside the cutting edge, or the use of a punched-out flow extending from the cutting edge transversely where the blade is bent out to provide a scoring edge. In the prior art, applicant is also aware of Canadian Patent No. 630,297 which issued Fahrni on Nov. 7, 1961, for A Process and Apparatus for Producing Shaving. Consistent with other prior art, Fahrni discloses the use of a shaving blade and a scoring blade, both mounted on a rotating disk where both the shaving blade and the scoring blade project from the disk face. Scoring blade includes a plurality of spaced groove-cutting projections which extend from the disk face by a distance slightly greater than the distance of the cutting edge of the shaving blade from the disk face. Fahrni also discloses that the shaving blade and the scoring blade may be included in a single unitary cutting means, or may be separate elements mounted in contact with each other or spaced from each other. SUMMARY OF THE INVENTION The device according to the present invention uses a heavy flywheel disc having a radially spaced apart array of pockets in which are mounted knives. In one embodiment, six pockets are used with the flywheel rotating at approximately 550 rpm. Short logs, which have been de-barked, are fed in with their long axis parallel to the face of the flywheel. A hydraulic ram forces the logs sideways into the plane containing the rotating knives. The use of the hydraulic ram provides for a variable infeed speed to obtain the particular thickness of shavings which provides in the end commercially shavings desirable for use, for example, in horse stables. If the ram pressure is too great, the scoring by means of the present invention of the wood slices so as to form strands, as better described below, may be defeated resulting in non-segmented sheets of shavings. The optimal depth of shaving cut may be approximately 0.004 of an inch, although it is intended that thicker cuts, for example 0.015 inches, may be made. The knives have notched cutting edges. The notches limit the width of each shaving to create strands which are for example ¾ inches wide. The strands are then chopped in an automated chopping device such as a forage harvester to produce shavings, for example approximately ¾ inch×¾ inch×0.004 inch in shape. In one aspect, the invention includes the use on the cutting edge on each knife of notches or slits formed into the cutting edge of the knife, where the notches or slits do not protrude from the edge of the knife, but which still operate to score the shaving to limit the length and width of the shaving. This creates ribbon-like shaving strands of controlled length and width which may then be chopped to form shavings. In summary, the present invention may be characterized as a device for producing shavings from woodpieces which includes an infeed for translating woodpieces in a direction of flow from an upstream loading position to a downstream shaving position. The woodpieces are oriented on the infeed transversely relative to the direction of flow. A flywheel is rotatably mounted transversely across the downstream position in the infeed. The axis of rotation of the flywheel may be substantially parallel to the direction of flow. The axis of rotation may bisect the infeed at the downstream position. The apertures and corresponding knives extend substantially from the axis of rotation radially outwardly. The flywheel has a radially spaced apart array of apertures formed therein, radially spaced around an axis of rotation of the flywheel. A radially spaced apart array of elongate slicing knives are mounted to the flywheel. Each knife has a cutting edge which is elevated and inclined at a cutting angle relative to an upstream face of the flywheel so as to slice into the woodpieces when a woodpiece is pressed against the upstream face by means for selectively pressing the woodpieces. The flywheel is rotated so as to bring sequentially each cutting edge into slicing engagement with the woodpiece. Each cutting edge has a spaced apart array of slits formed therein, spaced apart by a distance corresponding to a desired shaving-strand width dimension. The slits are formed so as to extend perpendicularly into the each knife from the cutting edge without any scoring protrusion protruding from the cutting edge. The strands are delivered to a means cooperating with the flywheel for cutting the strands into shavings. The means cooperating with the flywheel for cutting the strands into shavings may include a device such as a forage harvester having at least one knife for chopping the strands into shavings. The device may include a gravity-feed hopper for collecting the strands downstream of the flywheel and for feeding the strands to the chopping knife. A conveyor may be provided for conveying the strands from the flywheel into the hopper. A pair of counter-rotating rolls may be mounted at the downstream end of the conveyor for pressing the strands between the pair of rolls before the strands fall into the hopper. One roll of the pair of rolls may have a resilient outer surface. The strands as they are sliced from the woodpiece by the slicing engagement of the knives pass through a corresponding pocket and exit from a downstream face of the flywheel opposite the upstream face of the flywheel. The infeed at the downstream position may include a rigid housing for temporarily storing a queue of parallel woodpieces. The housing has an upstream infeed aperture for receiving the woodpieces in the direction of flow, and a downstream outfeed aperture adjacent the upstream face of the flywheel. The outfeed aperture is generally laterally centered on the axis of rotation. The means for selectively translating the woodpieces into the slicing engagement may include a selectively actuable actuator for urging a downstream-most woodpiece in the queue of woodpieces through the outfeed aperture into slicing engagement with the knives on the flywheel. The actuator is selectively actuable to controllably vary the forward speed of the actuator so as to control the feed speed of the downstream-most woodpiece. BRIEF DESCRIPTION OF THE DRAWINGS With reference to the drawings wherein similar characters of reference denote corresponding parts in each view: FIG. 1 is, in perspective view, the apparatus for producing wood shavings according to the present invention. FIG. 1a is an enlarged partially cut away view at the infeed face to the shaving disk as illustrated in FIG. 1 wherein the view is in front elevation view relative to the disk. FIG. 1b is, in partially cut away enlarged view, the infeed and shaving disk of FIG. 1. FIG. 1c is an enlarged view of a portion of FIG. 1a. FIG. 2 is, in partially cut away front elevation view, the apparatus of FIG. 1. FIG. 3 is, in plan view, the apparatus of FIG. 2. FIG. 4 is, in rear elevation view, the apparatus of FIG. 1b with the shaving disk housing removed. FIG. 4a is, in partially cut away enlarged view, a portion of FIG. 4. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION A chain conveyor 10 feeds log segments 12, typically logs cut to approximately three or four foot lengths (collectively herein referred to as logs), transversely on chainways 10a to an infeed aperture 14 feeding actuated log feeder 16. A log singulator 18 singulates and places logs into aperture 14. Logs from the singulator slide or roll across sheeted deck 16a so as to stack in a queue above and upstream of feeder actuator 16b. Actuator 16b drives log bearing member 16c in direction A, thereby driving logs transversely at a selectively controlled rate also in direction A so as to be engaged by log shaver 20. Log shaver 20 includes a planar flywheel 22 rotatably mounted on drive shaft 24 in a vertical plane orthogonal to direction A. A motor and drive coupling (not shown) rotates drive shaft 24 so as to rotate flywheel 22 in direction B. Flywheel 22 includes a radially spaced apart array of radially extending pockets or slots 22a. Slots 22a extend radially outwardly of axis of rotation C of flywheel 22. An elongate knife 26 is mounted in each slot 22a by a knife holder 28 bolted to the flywheel. Each knife 26 is angularly offset by approximately thirty degrees from the plane of the upstream face 32b of the flywheel and positioned so that a cutting edge 26a protrudes slightly beyond the plane of the upstream face 22b oppositely disposed to knives 26 across slots 22a. Wear plates 30 are inset almost entirely into upstream face 22b. The depth of cut of knives 26 is regulated by the mounting of knives 26 relative to the upstream surface of the wear plates. Optimally cutting edges 26a protrude approximately 0.004-0.015 inches beyond the wear surface of wear plates 30. In practice, the shaving thickness may vary depending on application and market of final products. Cutting edges 26a have notches or slits 32 in spaced apart array along their length. Slits may advantageously be 1/16 inches in width by 3/16 inches deep, and may be spaced apart approximately ¾ inches between each slit. A log 12 engaging cutting edges 26a while the flywheel is turning at approximately 550 rpm are shaved into strands 34 by the slicing into the log of successive cutting edges 26a and slits 32 moving in an arc relative to the transversely oriented log pressed against shaving face 22b and wear plates 30. The translation of cutting edges 26a and slits 32 in their arc, illustrated by way of example as arc D, slice the knives across the grain of the log shaving an elongate strand 34 having its length oriented generally at an angle across the wood grain direction. Strands 34 are truncated by engaging slits 32 in slicing engagement so as to slice across the log as the slits move in their semi-circular path relative to the log face so as to keep the strand from getting unmanageably long. For example, strands 34 may be in the order of four to 24 inches long. Strands 34 exit from the slots at the rear face 22c of the flywheel and drop onto, for transport in direction E, a conveyor 36. Conveyor 36 delivers strands 34 to a strand chopper 38 which reduces the length of strands 34 to a chip length of for example ¾ inch resulting in shavings which may be approximately ¾×¾ inches by 0.004 inches thick, depending on the pre-set depth-of-cut of the knives. The key to the shavings thickness is the very accurate control of the forward speed of the ram that presents the log to the disk. That is: Disk rpm of 550×6 pockets×0.004 inches per cut=13.2 inches of wood presented to the disc to be shaved to 0.004 inches per minute. The key to controlling the shavings to 0.004 inches is to control the forward speed of the ram to the 13.2 inches, not the pressure. If less than 13 inches is presented the shavings will be thinner, if more than 13 inches is presented, the shavings will be thicker. There are a number of ways to control the speed. In one embodiment, a controlled high pressure hydraulic system is used to control forward speed. Other systems that may be used include mechanical, pneumatic, variable frequency drives, gears etc. Strand chopper 38 includes a pair of transversely aligned closed adjacent parallel feed rolls 40a and 40b counter-rotating respectively in directions F and G. The surface of roll 40a has a softly resilient raised tread. The counter-rotating pair of rolls 40a and 40b form a nip 42 therebetween for accepting strands 34 from conveyor 36 into pinched engagement between the rolls. Strands 34 are pressed between the rolls, commencing through nip 42 and exiting downstream in direction H for gravity feed into a hopper 44 gravity feeding a strand chopper 46, such as a John Deere™ 3970 forage harvester. The forage harvester is statically-mounted and turned on end for the gravity infeed from hopper 44, to chop strands 34 into shorter shavings 34a by means of knives in the harvester cutting the strands against corresponding anvils or stationary blades. As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Devices for producing wood shavings from pieces of wood have long been known in art. By way of example, Canadian Patent No. 557,559 which issued to Steiner et al. on May 20, 1958, for an invention entitled Production of Shavings from Pieces of Wood discloses that it was then known to produce shavings for the manufacture of wood particle panels and other similar composite products. Pieces of wood waste are disintegrated on rotary-disk type shredding machines into shavings having pre-determined and properly chosen properties and dimensions, particularly shavings of a flat and pliably thin shape. Such rotary-disk machines include a rotating disk equipped with a number of blades whose edges extend along respective radii of the disk. Pieces of a wood of a given length are placed into a feed box which is traversed against the rotating blades. The shavings may be sub-divided by the use of scoring knives rotating together with and ahead of the cutter blades mounted on the rotating-disk. The blade-carrying disk extends in a vertical plane and has a horizontal shaft. The feed box is pressed and moved along with the woodpieces on a horizontal path towards the blades. Other prior art such as Canadian Patent Application No. 2,132,876 filed by Rice and published Sep. 30, 1993, entitled Apparatus and Method for Making Wood Curls discloses a mechanized disk flaker for producing curled food flakes. The disk flaker includes a rotatable disk plate having one or more cutting knives mounted to the disk plate so as to provide a slight rake angle between the tool face and a plane perpendicular to the direction of tool travel. The disk flaker includes rotatable and removable knife holders and also includes the use of scoring knives. In the prior art, applicant is also aware of Canadian Patent No. 991,833 which issued to Schaefer on Jun. 29, 1976, for A Knife for a Wood Shaving Machine. Schaefer discloses that the use of scoring knives may be replaced by the use scoring protrusions formed on the cutting edges of the knives used to produce wood shavings. In particular, Schaefer discloses the use of a bent-out cutting portion which results in a scoring edge, or a U or V-shaped bead which produces a scoring beak located outside the cutting edge, or the use of a punched-out flow extending from the cutting edge transversely where the blade is bent out to provide a scoring edge. In the prior art, applicant is also aware of Canadian Patent No. 630,297 which issued Fahrni on Nov. 7, 1961, for A Process and Apparatus for Producing Shaving. Consistent with other prior art, Fahrni discloses the use of a shaving blade and a scoring blade, both mounted on a rotating disk where both the shaving blade and the scoring blade project from the disk face. Scoring blade includes a plurality of spaced groove-cutting projections which extend from the disk face by a distance slightly greater than the distance of the cutting edge of the shaving blade from the disk face. Fahrni also discloses that the shaving blade and the scoring blade may be included in a single unitary cutting means, or may be separate elements mounted in contact with each other or spaced from each other. | <SOH> SUMMARY OF THE INVENTION <EOH>The device according to the present invention uses a heavy flywheel disc having a radially spaced apart array of pockets in which are mounted knives. In one embodiment, six pockets are used with the flywheel rotating at approximately 550 rpm. Short logs, which have been de-barked, are fed in with their long axis parallel to the face of the flywheel. A hydraulic ram forces the logs sideways into the plane containing the rotating knives. The use of the hydraulic ram provides for a variable infeed speed to obtain the particular thickness of shavings which provides in the end commercially shavings desirable for use, for example, in horse stables. If the ram pressure is too great, the scoring by means of the present invention of the wood slices so as to form strands, as better described below, may be defeated resulting in non-segmented sheets of shavings. The optimal depth of shaving cut may be approximately 0.004 of an inch, although it is intended that thicker cuts, for example 0.015 inches, may be made. The knives have notched cutting edges. The notches limit the width of each shaving to create strands which are for example ¾ inches wide. The strands are then chopped in an automated chopping device such as a forage harvester to produce shavings, for example approximately ¾ inch×¾ inch×0.004 inch in shape. In one aspect, the invention includes the use on the cutting edge on each knife of notches or slits formed into the cutting edge of the knife, where the notches or slits do not protrude from the edge of the knife, but which still operate to score the shaving to limit the length and width of the shaving. This creates ribbon-like shaving strands of controlled length and width which may then be chopped to form shavings. In summary, the present invention may be characterized as a device for producing shavings from woodpieces which includes an infeed for translating woodpieces in a direction of flow from an upstream loading position to a downstream shaving position. The woodpieces are oriented on the infeed transversely relative to the direction of flow. A flywheel is rotatably mounted transversely across the downstream position in the infeed. The axis of rotation of the flywheel may be substantially parallel to the direction of flow. The axis of rotation may bisect the infeed at the downstream position. The apertures and corresponding knives extend substantially from the axis of rotation radially outwardly. The flywheel has a radially spaced apart array of apertures formed therein, radially spaced around an axis of rotation of the flywheel. A radially spaced apart array of elongate slicing knives are mounted to the flywheel. Each knife has a cutting edge which is elevated and inclined at a cutting angle relative to an upstream face of the flywheel so as to slice into the woodpieces when a woodpiece is pressed against the upstream face by means for selectively pressing the woodpieces. The flywheel is rotated so as to bring sequentially each cutting edge into slicing engagement with the woodpiece. Each cutting edge has a spaced apart array of slits formed therein, spaced apart by a distance corresponding to a desired shaving-strand width dimension. The slits are formed so as to extend perpendicularly into the each knife from the cutting edge without any scoring protrusion protruding from the cutting edge. The strands are delivered to a means cooperating with the flywheel for cutting the strands into shavings. The means cooperating with the flywheel for cutting the strands into shavings may include a device such as a forage harvester having at least one knife for chopping the strands into shavings. The device may include a gravity-feed hopper for collecting the strands downstream of the flywheel and for feeding the strands to the chopping knife. A conveyor may be provided for conveying the strands from the flywheel into the hopper. A pair of counter-rotating rolls may be mounted at the downstream end of the conveyor for pressing the strands between the pair of rolls before the strands fall into the hopper. One roll of the pair of rolls may have a resilient outer surface. The strands as they are sliced from the woodpiece by the slicing engagement of the knives pass through a corresponding pocket and exit from a downstream face of the flywheel opposite the upstream face of the flywheel. The infeed at the downstream position may include a rigid housing for temporarily storing a queue of parallel woodpieces. The housing has an upstream infeed aperture for receiving the woodpieces in the direction of flow, and a downstream outfeed aperture adjacent the upstream face of the flywheel. The outfeed aperture is generally laterally centered on the axis of rotation. The means for selectively translating the woodpieces into the slicing engagement may include a selectively actuable actuator for urging a downstream-most woodpiece in the queue of woodpieces through the outfeed aperture into slicing engagement with the knives on the flywheel. The actuator is selectively actuable to controllably vary the forward speed of the actuator so as to control the feed speed of the downstream-most woodpiece. | 20040720 | 20070410 | 20060126 | 94120.0 | B27C100 | 0 | MILLER, BENA B | METHOD AND APPARATUS FOR PRODUCING WOOD SHAVINGS | SMALL | 0 | ACCEPTED | B27C | 2,004 |
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10,894,406 | ACCEPTED | Personal area network with automatic attachment and detachment | A network (100) includes a hub device (110) and at least one unattached peripheral device (120). The unattached peripheral device (120) transmits an attach request to the hub device (110) with a selected address, receives a new address from the hub device to identify the unattached peripheral device (120), and communicates with the hub device (110) using the new address. | 1. In a personal area network having at least one peripheral device not communicably attached to the network and a hub device connected to the network, a method for attaching the peripheral device to the network, comprising: transmitting, by the peripheral device, an attachment request to attach to the network with a selected address; receiving the attachment request by the hub device; generating a new address for the peripheral device in response to the received attachment request; sending the new address from the hub device to the peripheral device using the selected address; further communicating between the hub device and the peripheral device using the new address; and broadcasting, by the hub device, a heartbeat signal to begin an attach cycle. 2. The method of claim 1, further comprising: abandoning a current attach attempt by the peripheral device upon receipt of the heartbeat signal prior to receiving the new address from the hub device, and beginning a new attempt to attach to the network. 3. The method of claim 1, further comprising: broadcasting, by the hub device, a range of available addresses. 4. The method of claim 3, further comprising: selecting, by the peripheral device, an address from the range of available addresses to identify the peripheral device to the hub device in the attachment request. 5. The method of claim 4, further comprising: listening, by the hub device, for an address in the range of available addresses, for a signal from an unattached peripheral device. 6. The method of claim 1, further comprising: attaching the peripheral device to the network using the new address. 7. The method of claim 1, wherein the network further includes at least one other peripheral device communicably coupled to the hub device; and wherein the method further comprises: determining, by the hub device, whether a transmission from the other peripheral device was successful; and detaching the other peripheral device when the transmission fails to be successful in a predetermined number of attempts. 8. The method of claim 1, wherein the network further includes at least one other peripheral device communicably coupled to the hub device; and wherein the method further comprises: transmitting, by the hub device, a heartbeat signal to each of the other peripheral devices; and periodically transmitting, by the hub device, a keep-alive signal to each of the other peripheral devices. 9. The method of claim 8, further comprising: receiving the heartbeat signal at the other peripheral devices; receiving the keep-alive signal at the other peripheral devices; and detaching from the network when a predetermined number of heartbeat signals has been received prior to the keep-alive signal. 20. The method of claim 1, wherein the network further includes at least one other peripheral device communicably coupled to the hub device; and wherein the method further comprises: receiving, by the hub device, an attach request from one of the other peripheral devices, and detaching the other peripheral device in response to receipt of the attach request from the other peripheral device. 11. A hub device in a network having a plurality of attached peripheral devices and an unattached peripheral device, comprising: a memory having instructions for: broadcasting a range of available addresses, generating a new address to identify the unattached peripheral device in response to receipt of an attach request from the unattached peripheral device, the attach request identifying the unattached peripheral device to the hub device, sending the new address to the unattached peripheral device using the selected address, receiving confirmation from the unattached peripheral device using the new address, and sending a confirmation message to the unattached peripheral device using the new address; and a processor that executes the instructions in the memory. 12. The hub device of claim 11, wherein the memory further includes instructions for: broadcasting a heartbeat signal to begin an attach cycle. 13. The hub device of claim 12, wherein the instructions for broadcasting include: broadcasting a new range of available addresses with each heartbeat signal. 14. The hub device of claim 11, wherein the memory further includes instructions for: listening, for each of the addresses in the range of available addresses, for a signal from the unattached peripheral device. 15. The hub device of claim 11, wherein the memory further includes instructions for: determining whether a transmission from one of the attached peripheral devices was successful, and detaching the attached peripheral device when the transmission fails to be successful in a predetermined number of attempts. 16. A method for attaching an unattached peripheral device to a network having a hub device connected to a set of peripheral devices, the method, performed by the hub device, comprising: receiving an attach request from the unattached peripheral device, the attach request identifying the unattached peripheral device to the hub device; generating a new address to identify the unattached peripheral device in response to the received attach request; sending the new address to the unattached peripheral device; and sending a confirmation message to the unattached peripheral device using the new address to attach the unattached peripheral device. 17. The method of claim 16, further comprising: broadcasting a range of available addresses from which the unattached peripheral device selects to use when sending the attach request to the hub device. 18. The method of claim 17, further comprising: listening, for each of the addresses in the range of available addresses, for a signal from the unattached peripheral device; determining whether a transmission from the unattached peripheral device at one of the addresses was successful; and discarding an attach attempt by the unattached peripheral device at the one address when the transmission fails to be successful in a predetermined number of attempts. 19. The method of claim 16, further comprising: attaching the unattached peripheral device to the network to create a newly attached peripheral device capable of communicating with the hub device. 20. A computer-readable medium that stores instructions executable by a hub device to cause the hub device to perform a method for attaching an unattached peripheral device to a network, the method comprising: broadcasting a range of available addresses; listening, for each of the available addresses, for an attach request from an unattached peripheral device; generating a new address to identify the unattached peripheral device in response to receipt of the attach request from the unattached peripheral device, the attach request identifying the unattached peripheral device to the hub device; sending the new address to the unattached peripheral device; receiving confirmation from the peripheral device using the new address; and attaching the unattached peripheral device using the new address. 21. An unattached peripheral device in a network having a plurality of peripheral devices connected to a hub device, comprising: a memory having instructions for: selecting an address from a range of available addresses broadcast by the hub device to identify the unattached peripheral device to the hub device, transmitting an attach request with the selected address to the hub device, receiving a new address from the hub device to identify the unattached peripheral device, sending a confirmation message with the new address to the hub device, and attaching to the hub device using the new address; and a processor that executes the instructions in the memory. | RELATED APPLICATION This application is a continuation of U.S. patent application Ser. No. 09/535,591 filed on Mar. 27, 2000, which is related to U.S. patent application Ser. No. 09/536,191, filed on Mar. 27, 2000, both of which are incorporated herein by reference. BACKGROUND OF THE INVENTION A. Field of the Invention The present invention relates to a data network and, more particularly, to a star data network that facilitates bidirectional wireless data communications between a main processor unit and a varying number of peripheral units as they become located within the proximity of the processor unit. B. Description of Related Art Over the last decade, the size and power consumption of digital electronic devices has been progressively reduced. For example, personal computers have evolved from lap tops and notebooks into hand-held or belt-carriable devices commonly referred to as personal digital assistants (PDAs). One area of carriable devices that has remained troublesome, however, is the coupling of peripheral devices or sensors to the main processing unit of the PDA. Generally, such coupling is performed through the use of connecting cables. The connecting cables restrict the handling of a peripheral in such a manner as to lose many of the advantages inherent in the PDA's small size and light weight. For a sensor, for example, that occasionally comes into contact with the PDA, the use of cables is particularly undesirable. While some conventional systems have proposed linking a keyboard or a mouse to a main processing unit using infrared or radio frequency (RF) communications, such systems have typically been limited to a single peripheral unit with a dedicated channel of low capacity. Based on the foregoing, it is desirable to develop a low power data network that provides highly reliable bidirectional data communication between a host or server processor unit and a varying number of peripheral units and/or sensors while avoiding interference from nearby similar systems. SUMMARY OF THE INVENTION Systems and methods consistent with the present invention address this need by providing a wireless personal area network that permits a host unit to communicate with peripheral units with minimal interference from neighboring systems. A system consistent with the present invention includes a hub device and at least one unattached peripheral device. The unattached peripheral device transmits an attach request to the hub device with a selected address, receives a new address from the hub device to identify the unattached peripheral device, and communicates with the hub device using the new address. In another implementation consistent with the present invention, a method for attaching an unattached peripheral device to a network having a hub device connected to multiple peripheral devices, includes receiving an attach request from the unattached peripheral device, the attach request identifying the unattached peripheral device to the hub device; generating a new address to identify the unattached peripheral device in response to the received attach request; sending the new address to the unattached peripheral device; and sending a confirmation message to the unattached peripheral device using the new address to attach the unattached peripheral device. In yet another implementation consistent with the present invention, a method for attaching an unattached peripheral device to a network having a hub device connected to a set of peripheral devices, includes transmitting an attach request with a selected address to the hub device; receiving a new address from the hub device to identify the unattached peripheral device; and attaching to the network using the new address. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings: FIG. 1 is a diagram of a personal area network (PAN) in which systems and methods consistent with the present invention may be implemented; FIG. 2 is a simplified block diagram of the Hub of FIG. 1; FIG. 3 is a simplified block diagram of a PEA of FIG. 1; FIG. 4 is a block diagram of a software architecture of a Hub or PEA in an implementation consistent with the present invention; FIG. 5 is an exemplary diagram of communication processing by the layers of the software architecture of FIG. 4; FIG. 6 is an exemplary diagram of a data block architecture within the DCL of the Hub and PEA in an implementation consistent with the present invention; FIG. 7A is a detailed diagram of an exemplary stream usage plan in an implementation consistent with the present invention; FIG. 7B is a detailed diagram of an exemplary stream usage assignment in an implementation consistent with the present invention; FIG. 8 is an exemplary diagram of a time division multiple access (TDMA) frame structure in an implementation consistent with the present invention; FIG. 9A is a detailed diagram of activity within the Hub and PEA according to a TDMA plan consistent with the present invention; FIG. 9B is a flowchart of the Hub activity of FIG. 9A; FIG. 9C is a flowchart of the PEA activity of FIG. 9A; FIGS. 10A and 10B are high-level diagrams of states that the Hub and PEA traverse during a data transfer in an implementation consistent with the present invention; FIGS. 11 and 12 are flowcharts of Hub and PEA attachment processing, respectively, consistent with the present invention; and FIG. 13 is a flowchart of PEA detachment and reattachment processing consistent with the present invention. DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. Systems and methods consistent with the present invention provide a wireless personal area network that permits a host device to communicate with a varying number of peripheral devices with minimal interference from neighboring networks. The host device uses tokens to manage all of the communication in the network, and automatic attachment and detachment mechanisms to communicate with the peripheral devices. Network Overview A Personal Area Network (PAN) is a local network that interconnects computers with devices (e.g., peripherals, sensors, actuators) within their immediate proximity. These devices may be located nearby and may frequently or occasionally come within range and go out of range of the computer. Some devices may be embedded within an infrastructure (e.g., a building or vehicle) so that they can become part of a PAN as needed. A PAN, in an implementation consistent with the present invention, has low power consumption and small size, supports wireless communication without line-of-sight limitations, supports communication among networks of multiple devices (over 100 devices), and tolerates interference from other PAN systems operating within the vicinity. A PAN can also be easily integrated into a broad range of simple and complex devices, is low in cost, and is capable of being used worldwide. FIG. 1 is a diagram of a PAN 100 consistent with the present invention. The PAN 100 includes a single Hub device 110 surrounded by multiple Personal Electronic Accessory (PEA) devices 120 configured in a star topology. Other topologies may also be possible. Each device is identified by a Media Access (MAC) address. The Hub 110 orchestrates all communication in the PAN 100, which consists of communication between the Hub 110 and one or more PEA(s) 120. The Hub 110 manages the timing of the network, allocates available bandwidth among the currently attached PEAs 120 participating in the PAN 100, and supports the attachment, detachment, and reattachment of PEAs 120 to and from the PAN 100. The Hub 110 may be a stationary device or may reside in some sort of wearable computer, such as a simple pager-like device, that may move from peripheral to peripheral. The Hub 110 could, however, include other devices. The PEAs 120 may vary dramatically in terms of their complexity. A very simple PEA might include a movement sensor having an accelerometer, an 8-bit microcontroller, and a PAN interface. An intermediate PEA might include a bar code scanner and its microcontroller. More complex PEAs might include PDAs, cellular telephones, or even desktop PCs and workstations. The PEAs may include stationary devices located near the Hub and/or portable devices that move to and away from the Hub. The Hub 110 and PEAs 120 communicate using multiplexed communication over a predefined set of streams. Logically, a stream is a one-way communications link between one PEA 120 and its Hub 110. Each stream has a predetermined size and direction. The Hub 110 uses stream numbers to identify communication channels for specific functions (e.g., data and control). The Hub 110 uses MAC addresses to identify itself and the PEAs 120. The Hub 110 uses its own MAC address to broadcast to all PEAs 120. The Hub 110 might also use MAC addresses to identify virtual PEAs within any one physical PEA 120. The Hub 110 combines a MAC address and a stream number into a token, which it broadcasts to the PEAs 120 to control communication through the network 100. The PEA 120 responds to the Hub 110 if it identifies its own MAC address or the Hub MAC address in the token and if the stream number in the token is active for the MAC address of the PEA 120. Exemplary Hub Device FIG. 2 is a simplified block diagram of the Hub 110 of FIG. 1. The Hub 110 may be a battery-powered device that includes Hub host 210, digital control logic 220, radio frequency (RF) transceiver 230, and an antenna 240. Hub host 210 may include anything from a simple microcontroller to a high performance microprocessor. The digital control logic (DCL) 220 may include a controller that maintains timing and coordinates the operations of the Hub host 210 and the RF transceiver 230. The DCL 220 is specifically designed to minimize power consumption, cost, and size of the Hub 110. Its design centers around a time-division multiple access (TDMA)-based network access protocol that exploits the short range nature of the PAN 100. The Hub host 210 causes the DCL 220 to initialize the network 100, send tokens and messages, and receive messages. Responses from the DCL 220 feed incoming messages to the Hub host 210. The RF transceiver 230 includes a conventional RF transceiver that transmits and receives information via the antenna 240. The RF transceiver 230 may alternatively include separate transmitter and receiver devices controlled by the DCL 220. The antenna 240 includes a conventional antenna for transmitting and receiving information over the network. While FIG. 2 shows the exemplary Hub 110 as consisting of three separate elements, these elements may be physically implemented in one or more integrated circuits. For example, the Hub host 210 and the DCL 220, the DCL 220 and the RF transceiver 230, or the Hub host 210, the DCL 220, and the RF transceiver 230 may be implemented as a single integrated circuit or separate integrated circuits. Moreover, one skilled in the art will recognize that the Hub 110 may include additional elements that aid in the sending, receiving, and processing of data. Exemplary PEA Device FIG. 3 is a simplified block diagram of the PEA 120. The PEA 120 may be a battery-powered device that includes a PEA host 310, DCL 320, RF transceiver 330, and an antenna 340. The PEA host 310 may include a sensor that responds to information from a user, an actuator that provides output to the user, a combination of a sensor and an actuator, or more complex circuitry, as described above. The DCL 320 may include a controller that coordinates the operations of the PEA host 310 and the RF transceiver 330. The DCL 320 sequences the operations necessary in establishing synchronization with the Hub 110, in data communications, in coupling received information from the RF transceiver 330 to the PEA host 310, and in transmitting data from the PEA host 310 back to the Hub 110 through the RF transceiver 330. The RF transceiver 330 includes a conventional RF transceiver that transmits and receives information via the antenna 340. The RF transceiver 330 may alternatively include separate transmitter and receiver devices controlled by the DCL 320. The antenna 340 includes a conventional antenna for transmitting and receiving information over the network. While FIG. 3 shows the exemplary PEA 120 as consisting of three separate elements, these elements may be physically implemented in one or more integrated circuits. For example, the PEA host 310 and the DCL 320, the DCL 320 and the RF transceiver 330, or the PEA host 310, the DCL 320, and the RF transceiver 330 may be implemented as a single integrated circuit or separate integrated circuits. Moreover, one skilled in the art will recognize that the PEA 120 may include additional elements that aid in the sending, receiving, and processing of data. Exemplary Software Architecture FIG. 4 is an exemplary diagram of a software architecture 400 of the Hub 110 in an implementation consistent with the present invention. The software architecture 400 in the PEA 120 has a similar structure. The software architecture 400 includes several distinct layers, each designed to serve a specific purpose, including: (1) application 410, (2) link layer control (LLC) 420, (3) network interface (NI) 430, (4) link layer transport (LLT) 440, (5) link layer driver (LLD) 450, and (6) DCL hardware 460. The layers have application programming interfaces (APIs) to facilitate communication with lower layers. The LLD 450 is the lowest layer of software. Each layer may communicate with the next higher layer via procedural upcalls that the higher layer registers with the lower layer. The application 410 may include any application executing on the Hub 110, such as a communication routine. The LLC 420 performs several miscellaneous tasks, such as initialization, attachment support, bandwidth control, and token planning. The LLC 420 orchestrates device initialization, including the initialization of the other layers in the software architecture 400, upon power-up. The LLC 420 provides attachment support by providing attachment opportunities for unattached PEAs to attach to the Hub 110 so that they can communicate, providing MAC address assignment, and initializing an NI 430 and the layers below it for communication with a PEA 120. The LLC 420 provides bandwidth control through token planning. Through the use of tokens, the LLC 420 allocates bandwidth to permit one PEA 120 at a time to communicate with the Hub 110. The NI 430 acts on its own behalf, or for an application 410 layer above it, to deliver data to the LLT 440 beneath it. The LLT 440 provides an ordered, reliable “snippet” (i.e., a data block) delivery service for the NI 430 through the use of encoding (e.g., 16-64 bytes of data plus a cyclic redundancy check (CRC)) and snippet retransmission. The LLT 440 accepts snippets, in order, from the NI 430 and delivers them using encoded status blocks (e.g., up to 2 bytes of status information translated through Forward Error Correction (FEC) into 6 bytes) for acknowledgments (ACKs). The LLD 450 is the lowest level of software in the software architecture 400. The LLD 450 interacts with the DCL hardware 460. The LLD 450 initializes and updates data transfers via the DCL hardware 460 as it delivers and receives data blocks for the LLT 440, and processes hardware interrupts. The DCL hardware 460 is the hardware driven by the LLD 450. FIG. 5 is an exemplary diagram of communication processing by the layers of the software architecture 400 of FIG. 4. In FIG. 5, the exemplary communications involve the transmission of a snippet from one node to another. This example assumes that the sending node is the Hub 110 and the receiving node is a PEA 120. Processing begins with the NI 430 of the Hub 110 deciding to send one or more bytes (but no more than will fit) in a snippet. The NI 430 exports the semantics that only one transaction is required to transmit these bytes to their destination (denoted by “(1)” in the figure). The NI 430 sends a unique identifier for the destination PEA 120 of the snippet to the LLT 440. The LLT 440 maps the PEA identifier to the MAC address assigned to the PEA 120 by the Hub 110. The LLT 440 transmits the snippet across the network to the receiving device. To accomplish this, the LLT 440 adds header information (to indicate, for example, how many bytes in the snippet are padded bytes) and error checking information to the snippet, and employs reverse-direction status/acknowledgment messages and retransmissions. This is illustrated in FIG. 5 by the bidirectional arrow between the LLT 440 layers marked with “(n+m).” The number n of snippet transmissions and the number m of status transmissions in the reverse direction are mostly a function of the amount of noise in the wireless communication, which may be highly variable. The LLT 440 may also encrypt portions or all of the snippet using known encryption technology. The LLT 440 uses the LLD 450 to provide a basic block and stream-oriented communications service, isolating the DCL 460 interface from the potentially complex processing required of the LLT 440. The LLT 440 uses multiple stream numbers to differentiate snippet and status blocks so that the LLD 450 need not know which blocks contain what kind of content. The LLD 450 reads and writes the hardware DCL 460 to trigger the transmission and reception of data blocks. The PEA LLT 440, through the PEA LLD 450, instructs the PEA DCL 460 which MAC address or addresses to respond to, and which stream numbers to respond to for each MAC address. The Hub LLT 440, through the Hub LLD 450, instructs the Hub DCL 460 which MAC addresses and stream numbers to combine into tokens and transmit so that the correct PEA 120 will respond. The Hub DCL 460 sends and receives (frequently in a corrupted form) the data blocks across the RF network via the Hub RF transceiver 230 (FIG. 2). The Hub LLT 440 employs FEC for status, checksums and error checking for snippets, and performs retransmission control for both to ensure that each snippet is delivered reliably to its client (e.g., PEA LLT 440). The PEA LLT 440 delivers snippets in the same order that they were sent by the Hub NI 430 to the PEA NI 430. The PEA NI 430 takes the one or more bytes sent in the snippets and delivers them in order to the higher-level application 410, thereby completing the transmission. Exemplary DCL Data Block Architecture FIG. 6 is an exemplary diagram of a data block architecture 600 within the DCL of the Hub 110 and the PEA 120. The data block 600 contains a MAC address 610 designating a receiving or sending PEA 120, a stream number 620 for the communication, and a data buffer 630 which is full when sending and empty when receiving. As will be described later, the MAC address 610 and stream number 620 form the contents of a token 640. When the LLD 450 reads from and writes to the hardware DCL 460, the LLD 450 communicates the MAC address 610 and stream number 620 with the data buffer 630. When a PEA 120 receives a data block, the DCL 460 places the MAC address 610 and stream number 620 contained in the preceding token 640 in the data block 600 to keep track of the different data flows. Exemplary Stream Architecture The LLD 450 provides a multi-stream data transfer service for the LLT 440. While the LLT 440 is concerned with data snippets and status/acknowledgements, the LLD 450 is concerned with the size of data blocks and the direction of data transfers to and from the Hub 110. FIG. 7A is a detailed diagram of an exemplary stream usage plan 700 in an implementation consistent with the present invention. A single stream usage plan may be predefined and used by the Hub 110 and all PEAs 120. The PEA 120 may have a different set of active streams for each MAC address it supports, and only responds to a token that specifies a MAC address of the PEA 120 and a stream that is active for that MAC address. In an implementation consistent with the present invention, every PEA 120 may support one or more active Hub-to-PEA streams associated with the Hub's MAC address. The stream usage plan 700 includes several streams 710-740, each having a predefined size and data transfer direction. The plan 700 may, of course, have more or fewer entries and may accommodate more than the two data block sizes shown in the figure. In the plan 700, streams 0-2 (710) are used to transmit the contents of small data blocks from the PEA 120 to the Hub 110. Streams 3-7 (720) are used to transmit the contents of larger data blocks from the PEA 120 to the Hub 110. Streams 8-10 (730), on the other hand, are used to transmit the contents of small data blocks from the Hub 110 to the PEA 120. Streams 11-15 (740) are used to transmit the contents of larger data blocks from the Hub 110 to the PEA 120. To avoid collisions, some of the streams are reserved for PEAs desiring to attach to the network and the rest are reserved for PEAs already attached to the network. With such an arrangement, a PEA 120 knows whether and what type of communication is scheduled by the Hub 110 based on a combination of the MAC address 610 and the stream number 620. FIG. 7B is a detailed diagram of an exemplary stream usage assignment by the LLT 440 in an implementation consistent with the present invention. The LLT 440 assigns different streams to different communication purposes, reserving the streams with small block size for status, and using the streams with larger block size for snippets. For example, the LLT 440 may use four streams (4-7 and 12-15) for the transmission of snippets in each direction, two for odd parity snippets and two for even parity snippets. In other implementations consistent with the present invention, the LLT 440 uses different numbers of streams of each parity and direction. The use of more than one stream for the same snippet allows a snippet to be sent in more than one form. For example, the LLT 440 may send a snippet in its actual form through one stream and in a form with bytes complemented and in reverse order through the other stream. The alternating use of different transformations of a snippet more evenly distributes transmission errors among the bits of the snippet as they are received, and hence facilitates the reconstruction of a snippet from multiple corrupted received versions. The receiver always knows which form of the snippet was transmitted based on its stream number. The LLT 440 partitions the streams into two disjoint subsets, one for use with Hub 110 assigned MAC addresses 750 and the other for use with attaching PEAs' self-selected MAC addresses (AMACs) 760. Both the LLT 440 and the LLD 450 know the size and direction of each stream, but the LLT 450 is responsible for determining how the streams are used, how MAC numbers are assigned and used, and assuring that no two PEAs 120 respond to the same token (containing a MAC address and stream number) transmitted by the Hub 110. One exception to this includes the Hub's use of its MAC address to broadcast its heartbeat 770 (described below) to all PEAs 120. Exemplary Communication FIG. 8 is an exemplary diagram of a TDMA frame structure 800 of a TDMA plan consistent with the present invention. The TDMA frame 800 starts with a beacon 810, and then alternates token broadcasts 820 and data transfers 830. The Hub 110 broadcasts the beacon 810 at the start of each TDMA frame 800. The PEAs 120 use the beacon 810, which may contain a unique identifier of the Hub 110, to synchronize to the Hub 110. Each token 640 (FIG. 6) transmitted by the Hub 110 in a token broadcast 820 includes a MAC address 610 (FIG. 6) and a stream number 620 for the data buffer 630 transfer that follows. The MAC address 610 and stream number 620 in the token 640 together specify a particular PEA 120 to transmit or receive data, or, in the case of the Hub's MAC address 610, specify no, many, or all PEAs to receive data from the Hub 110 (depending on the stream number). The stream number 620 in the token 640 indicates the direction of the data transfer 830 (Hub 110 to PEA 120 or PEA 120 to Hub 110), the number of bytes to be transferred, and the data source (for the sender) and the appropriate empty data block (for the receiver). The TDMA plan controls the maximum number of bytes that can be sent in a data transfer 830. Not all of the permitted bytes need to be used in the data transfer 830, however, so the Hub 110 may schedule a status block in the initial segment of a TDMA time interval that is large enough to send a snippet. The Hub 110 and PEA 120 treat any left over bytes as no-ops to mark time. Any PEA 120 not involved in the data transfer uses all of the data transfer 830 bytes to mark time while waiting for the next token 640. The PEA 120 may also power down non-essential circuitry at this time to reduce power consumption. FIG. 9A is an exemplary diagram of communication processing for transmitting a single data block from the Hub 110 to a PEA 120 according to the TDMA plan of FIG. 8. FIGS. 9B and 9C are flowcharts of the Hub 110 and PEA 120 activities, respectively, of FIG. 9A. The reference numbers in FIG. 9A correspond to the flowchart steps of FIGS. 9B and 9C. With regard to the Hub activity, the Hub 110 responds to a token command in the TDMA plan [step 911] (FIG. 9B) by determining the location of the next data block 600 to send or receive [step 912]. The Hub 110 reads the block's MAC address 610 and stream number 620 [step 913] and generates a token 640 from the MAC address and stream number using FEC [step 914]. The Hub 110 then waits for the time for sending a token 640 in the TDMA plan (i.e., a token broadcast 820 in FIG. 8) [step 915] and broadcasts the token 640 to the PEAs 120 [step 916]. If the stream number 620 in the token 640 is zero (i.e., a NO-DATA-TRANSFER token), no PEA 120 will respond and the Hub 110 waits for the next token command in the TDMA plan [step 911]. If the stream number 620 is non-zero, however, the Hub 110 determines the size and direction of the data transmission from the stream number 620 and waits for the time for sending the data in the TDMA plan (i.e., a data transfer 830) [step 917]. Later, when instructed to do so by the TDMA plan (i.e., after the PEA 120 identified by the MAC address 610 has had enough time to prepare), the Hub 110 transmits the contents of the data buffer 630 [step 918]. The Hub 110 then prepares for the next token command in the TDMA plan [step 919]. With regard to the PEA activity, the PEA 120 reaches a token command in the TDMA plan [step 921] (FIG. 9C). The PEA 120 then listens for the forward error-corrected token 640, having a MAC address 610 and stream number 620, transmitted by the Hub 110 [step 922]. The PEA 120 decodes the MAC address from the forward error-corrected token [step 923] and, if it is not the PEA's 120 MAC address, sleeps through the next data transfer 830 in the TDMA plan [step 924]. Otherwise, the PEA 120 also decodes the stream number 620 from the token 640. All PEAs 120 listen for the Hub heartbeat that the Hub 110 broadcasts with a token containing the Hub's MAC address 610 and the heartbeat stream 770. During attachment (described in more detail below), the PEA 120 may have two additional active MAC addresses 610, the one it selected for attachment and the one the Hub 110 assigned to the PEA 120. The streams are partitioned between these three classes of MAC addresses 610, so the PEA 120 may occasionally find that the token 640 contains a MAC address 610 that the PEA 120 supports, but that the stream number 620 in the token 640 is not one that the PEA 120 supports for this MAC address 610. In this case, the PEA 120 sleeps through the next data transfer 830 in the TDMA plan [step 924]. Since the PEA 120 supports more than one MAC address 610, the PEA 120 uses the MAC address 610 and the stream number 620 to identify a suitable empty data block [step 925]. The PEA 120 writes the MAC address 610 and stream number 620 it received in the token 640 from the Hub 110 into the data block [step 926]. The PEA 120 then determines the size and direction of the data transmission from the stream number 620 and waits for the transmission of the data buffer 630 contents from the Hub 110 during the next data transfer 830 in the TDMA plan [step 927]. The PEA 120 stores the data in the data block [step 928], and then prepares for the next token command in the TDMA plan [step 929]. FIGS. 9A-9C illustrate communication of a data block from the Hub 110 to a PEA 120. When the PEA 120 transfers a data block to the Hub 110, similar steps occur except that the Hub 110 first determines the next data block to receive (with its MAC address 610 and stream number 620) and the transmission of the data buffer 630 contents occurs in the opposite direction. The Hub 110 needs to arrange in advance for receiving data from PEAs 120 by populating the MAC address 610 and stream number 620 into data blocks with empty data buffers 630, because the Hub 110 generates the tokens for receiving data as well as for transmitting data. FIGS. 10A and 10B are high-level diagrams of the states that the Hub 110 and PEA 120 LLT 440 (FIG. 4) go through during a data transfer in an implementation consistent with the present invention. FIG. 10A illustrates states of a Hub-to-PEA transfer and FIG. 10B illustrates states of a PEA-to-Hub transfer. During the Hub-to-PEA transfer (FIG. 10A), the Hub 110 cycles through four states: fill, send even parity, fill, and send odd parity. The fill states indicate when the NI 430 (FIG. 4) may fill a data snippet. The even and odd send states indicate when the Hub 110 sends even numbered and odd numbered snippets to the PEA 120. The PEA 120 cycles through two states: want even and want odd. The two states indicate the PEA's 120 desire for data, with ‘want even’ indicating that the last snippet successfully received had odd parity. The PEA 120 communicates its current state to the Hub 110 via its status messages (i.e., the state changes serve as ACKs). The Hub 110 waits for a state change in the PEA 120 before it transitions to its next fill state. During the PEA-to-Hub transfer (FIG. 101B), the Hub 110 cycles through six states: wait/listen for PEA-ready-to-send-even status, read even, send ACK and listen for status, wait/listen for PEA-ready-to-send-odd status, read odd, and send ACK and listen for status. According to this transfer, the PEA 120 cannot transmit data until the Hub 110 requests data, which it will only do if it sees from the PEA's status that the PEA 120 has the next data block ready. The four listen for status states schedule when the Hub 110 asks to receive a status message from the PEA 120. The two ‘send ACK and listen for status’ states occur after successful receipt of a data block by the Hub 110, and in these two states the Hub 110 schedules both the sending of Hub status to the PEA 120 and receipt of the PEA status. The PEA status informs the Hub 110 when the PEA 120 has successfully received the Hub 110 status and has transitioned to the next ‘fill’ state. Once the PEA 120 has prepared its next snippet, it changes its status to ‘have even’ or ‘have odd’ as appropriate. When the Hub 110 detects that the PEA 120 has advanced to the fill state or to ‘have even/odd,’ it stops scheduling the sending of Hub status (ACK) to the PEA 120. If the Hub 110 detects that the PEA 120 is in the ‘fill’ state, it transitions to the following ‘listen for status’ state. If the PEA 120 has already prepared a new snippet for transmission by the time the Hub 110 learns that its ACK was understood by the PEA 120, the Hub 110 skips the ‘listen for status’ state and moves immediately to the next appropriate ‘read even/odd’ state. In this state, the Hub 110 receives the snippet from the PEA 120. The PEA 120 cycles through four states: fill, have even, fill, and have odd (i.e., the same four states the Hub 110 cycles through when sending snippets). The fill states indicate when the NI 430 (FIG. 4) can fill a data snippet. During the fill states, the PEA 110 sets its status to ‘have nothing to send.’ The PEA 120 does not transition its status to ‘have even’ or ‘have odd’ until the next snippet is filled and ready to send to the Hub 110. These two status states indicate the parity of the snippet that the PEA 120 is ready to send to the Hub 110. When the Hub 110 receives a status of ‘have even’ or ‘have odd’ and the last snippet it successfully received had the opposite parity, it schedules the receipt of data, which it thereafter acknowledges with a change of status that it sends to the PEA 120. Exemplary Attachment Processing The Hub 110 communicates with only attached PEAs 120 that have an assigned MAC address 610. An unattached PEA can attach to the Hub 110 when the Hub 110 gives it an opportunity to do so. Periodically, the Hub 110 schedules attachment opportunities for unattached PEAs that wish to attach to the Hub 110, using a small set of attach MAC (AMAC) addresses and a small set of streams dedicated to this purpose. After selecting one of the designated AMAC addresses 610 at random to identify itself and preparing to send a small, possibly forward error-corrected, “attach-interest” message and a longer, possibly checksummed, “attach-request” message using this AMAC and the proper attach stream numbers 620, the PEA 120 waits for the Hub 110 to successfully read the attach-interest and then the attach-request messages. Reading of a valid attach-interest message by the Hub 110 causes the Hub 110 believe that there is a PEA 120 ready to send the longer (and hence more likely corrupted) attach-request. Once a valid attach-interest is received, the Hub 110 schedules frequent receipt of the attach-request until it determines the contents of the attach-request, either by receiving the block intact with a valid checksum or by reconstructing the sent attach-request from two or more received instances of the sent attach-request. The Hub 110 then assigns a MAC address to the PEA 120, sending the address to the PEA 120 using its AMAC address. The Hub 110 confirms receipt of the MAC address by scheduling the reading of a small, possibly forward error-corrected, attach-confirmation from the PEA 120 at its new MAC address 610. The Hub 110 follows this by sending a small, possibly forward error-corrected, confirmation to the PEA 120 at its MAC address so that the PEA 120 knows it is attached. The PEA 120 returns a final small, possibly forward error-corrected, confirmation acknowledgement to the Hub 110 so that the Hub 110, which is in control of all scheduled activity, has full knowledge of the state of the PEA 120. This MAC address remains assigned to that PEA 120 for the duration of the time that the PEA 120 is attached. FIGS. 11 and 12 are flowcharts of Hub and PEA attachment processing, respectively, consistent with the present invention. When the Hub 110 establishes the network, its logic initializes the attachment process and, as long as the Hub 110 continues to function, periodically performs attachment processing. The Hub 110 periodically broadcasts heartbeats containing a Hub identifier (selecting a new heartbeat identifier value each time it reboots) and an indicator of the range of AMACs that can be selected from for the following attach opportunity [step 1110] (FIG. 11). The Hub 110 schedules an attach-interest via a token that schedules a small PEA-to-Hub transmission for each of the designated AMACs, so unattached PEAs may request attachment. Each attaching PEA 120 selects a new AMAC at random from the indicated range when it hears the heartbeat. Because the Hub 110 may receive a garbled transmission whenever more than one PEA 120 transmits, the Hub 110 occasionally indicates a large AMAC range (especially after rebooting) so that at least one of a number of PEAs 120 may select a unique AMAC 610 and become attached. When no PEAs 120 have attached for some period of time, however, the Hub 110 may select a small range of AMACs 610 to reduce attachment overhead, assuming that PEAs 120 will arrive in its vicinity in at most small groups. The Hub 110 then listens for a valid attach-interest from an unattached PEA [step 1120]. The attach-interest is a PEA-to-Hub message having the AMAC address 610 selected by the unattached PEA 120. Upon receiving a valid attach interest, the Hub 110 schedules a PEA-to-Hub attach-request token with the PEA's AMAC 610 and reads the PEA's attach-request [step 1130]. Due to the low-power wireless environment of the PAN 100, the attach-request transmission may take more than one attempt and hence may require scheduling the PEA-to-Hub attach-request token more than once. When the Hub 110 successfully receives the attach-request from the PEA, it assigns a MAC address to the PEA [step 1140]. In some cases, the Hub 110 chooses the MAC address from the set of AMAC addresses. The Hub 110 sends the new MAC address 610 in an attach-assignment message to the now-identified PEA 120, still using the PEA's AMAC address 610 and a stream number 620 reserved for this purpose. The Hub 110 schedules and listens for an attach-confirmation response from the PEA 120 using the newly assigned MAC address 610 [step 1150]. Upon receiving the confirmation from the PEA 120, the Hub 110 sends its own confirmation, acknowledging that the PEA 120 has switched to its new MAC, to the PEA 120 and waits for a final acknowledgment from the PEA 120 [step 1160]. The Hub 110 continues to send the confirmation until it receives the acknowledgment from the PEA 120 or until it times out. In each of the steps above, the Hub 110 counts the number of attempts it makes to send or receive, and aborts the attachment effort if a predefined maximum number of attempts is exceeded. Upon receiving the final acknowledgment, the Hub 110 stops sending its attach confirmation, informs its NI 430 (FIG. 4) that the PEA 120 is attached, and begins exchanging both data and keep-alive messages (described below) with the PEA 120. When an unattached PEA 120 enters the network, its LLC 420 (FIG. 4) instructs its LLT 440 to initialize attachment. Unlike the Hub 110, the PEA 120 waits to be polled. The PEA 120 instructs its DCL 460 to activate and associate the heartbeat stream 770 (FIG. 7B) with the Hub's MAC address and waits for the heartbeat broadcast from the Hub 110 [step 1210] (FIG. 12). The PEA 120 then selects a random AMAC address from the range indicated in the heartbeat to identify itself to the Hub 110 [step 1220]. The PEA 120 instructs its DCL 460 to send an attach-interest and an attach-request data block to the Hub 110, and activate and associate the streams with its AMAC address [step 1230]. The PEA 120 tells its driver to activate and respond to the selected AMAC address for the attach-assignment stream. The unattached PEA 120 then waits for an attach-assignment with an assigned MAC address from the Hub 110 [step 1240]. Upon receiving the attach-assignment, the PEA 120 finds its Hub-assigned MAC address and tells its driver to use this MAC address to send an attach-confirmation to the Hub 110 to acknowledge receipt of its new MAC address [step 1250], activate all attached-PEA streams for its new MAC address, and deactivate the streams associated with its AMAC address. The PEA 120 waits for an attach confirmation from the Hub 110 using the new MAC address [step 1260] and, upon receiving it, sends a final acknowledgment to the Hub 110 [step 1270]. The PEA 120 then tells its NI 430 that it is attached. The PEA 120, if it hears another heartbeat from the Hub 110 before it completes attachment, discards any prior communication and begins its attachment processing over again with a new AMAC. Exemplary Detachment and Reattachment Processing The Hub 110 periodically informs all attached PEAs 120 that they are attached by sending them ‘keep-alive’ messages. The Hub 110 may send the messages at least as often as it transmits heartbeats. The Hub 110 may send individual small, possibly forward error-corrected, keep-alive messages to each attached PEA 120 when few PEAs 120 are attached, or may send larger, possibly forward error-corrected, keep-alive messages to groups of PEAs 120. Whenever the Hub 110 schedules tokens for PEA-to-Hub communications, it sets a counter to zero. The counter resets to zero each time the Hub 110 successfully receives a block (either uncorrupted or reconstructed) from the PEA 120, and increments for unreadable blocks. If the counter exceeds a predefined threshold, the Hub 110 automatically detaches the PEA 120 without any negotiation with the PEA 120. After this happens, the Hub 110 no longer schedules data or status transfers to or from the PEA 120, and no longer sends it any keep-alive messages. FIG. 13 is a flowchart of PEA detachment and reattachment processing consistent with the present invention. Each attached PEA 120 listens for Hub heartbeat and keep-alive messages [step 1310]. When the PEA 120 first attaches, and after receiving each keep-alive message, it resets its heartbeat counter to zero [step 1320]. Each time the PEA 120 hears a heartbeat, it increments the heartbeat counter [step 1330]. If the heartbeat counter exceeds a predefined threshold, the PEA 120 automatically assumes that the Hub 110 has detached it from the network 100 [step 1340]. After this happens, the PEA 120 attempts to reattach to the Hub 110 [step 1350], using attachment processing similar to that described with respect to FIGS. 11 and 12. If the Hub 110 had not actually detached the PEA 120, then the attempt to reattach causes the Hub 110 to detach the PEA 120 so that the attempt to reattach can succeed. When the PEA 120 is out of range of the Hub 110, it may not hear from the Hub 110 and, therefore, does not change state or increment its heartbeat counter. The PEA 120 has no way to determine whether the Hub 110 has detached it or how long the Hub 110 might wait before detaching it. When the PEA 120 comes back into range of the Hub 110 and hears the Hub heartbeat (and keep-alive if sent), the PEA 120 then determines whether it is attached and attempts to reattach if necessary. CONCLUSION Systems and methods consistent with the present invention provide a wireless personal area network that permit a host device to communicate with a varying number of peripheral devices with minimal power and minimal interference from neighboring networks by using a customized TDMA protocol. The host device uses tokens to facilitate the transmission of data blocks through the network. The foregoing description of exemplary embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The scope of the invention is defined by the claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>A. Field of the Invention The present invention relates to a data network and, more particularly, to a star data network that facilitates bidirectional wireless data communications between a main processor unit and a varying number of peripheral units as they become located within the proximity of the processor unit. B. Description of Related Art Over the last decade, the size and power consumption of digital electronic devices has been progressively reduced. For example, personal computers have evolved from lap tops and notebooks into hand-held or belt-carriable devices commonly referred to as personal digital assistants (PDAs). One area of carriable devices that has remained troublesome, however, is the coupling of peripheral devices or sensors to the main processing unit of the PDA. Generally, such coupling is performed through the use of connecting cables. The connecting cables restrict the handling of a peripheral in such a manner as to lose many of the advantages inherent in the PDA's small size and light weight. For a sensor, for example, that occasionally comes into contact with the PDA, the use of cables is particularly undesirable. While some conventional systems have proposed linking a keyboard or a mouse to a main processing unit using infrared or radio frequency (RF) communications, such systems have typically been limited to a single peripheral unit with a dedicated channel of low capacity. Based on the foregoing, it is desirable to develop a low power data network that provides highly reliable bidirectional data communication between a host or server processor unit and a varying number of peripheral units and/or sensors while avoiding interference from nearby similar systems. | <SOH> SUMMARY OF THE INVENTION <EOH>Systems and methods consistent with the present invention address this need by providing a wireless personal area network that permits a host unit to communicate with peripheral units with minimal interference from neighboring systems. A system consistent with the present invention includes a hub device and at least one unattached peripheral device. The unattached peripheral device transmits an attach request to the hub device with a selected address, receives a new address from the hub device to identify the unattached peripheral device, and communicates with the hub device using the new address. In another implementation consistent with the present invention, a method for attaching an unattached peripheral device to a network having a hub device connected to multiple peripheral devices, includes receiving an attach request from the unattached peripheral device, the attach request identifying the unattached peripheral device to the hub device; generating a new address to identify the unattached peripheral device in response to the received attach request; sending the new address to the unattached peripheral device; and sending a confirmation message to the unattached peripheral device using the new address to attach the unattached peripheral device. In yet another implementation consistent with the present invention, a method for attaching an unattached peripheral device to a network having a hub device connected to a set of peripheral devices, includes transmitting an attach request with a selected address to the hub device; receiving a new address from the hub device to identify the unattached peripheral device; and attaching to the network using the new address. | 20040719 | 20070515 | 20050310 | 86500.0 | 1 | PHAN, MAN U | PERSONAL AREA NETWORK WITH AUTOMATIC ATTACHMENT AND DETACHMENT | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,894,428 | ACCEPTED | Spreader | Apparatus for use with a hand manipulable flowable material dispenser, the combination comprising a dispensing nozzle associated with the dispenser to dispense material, and a spreader surface associated with the nozzle whereby the dispenser may be manipulated to cause the spreader surface to spread material dispensed via the nozzle, and the spreader surface can be used to spread material around after it is dispensed. | 1-63. (canceled) 64. The spreader of claim 29 wherein the nozzle has orifices which are covered by inwardly biased nipples which push open upon the application of pressure. 65. An applicator and spreader comprising: a container, having a closed end and an open end, capable of holding a spreadable food item; and a flip having a plurality of grooves being in fluid communication with the open end of the container such that the spreadable food item can be applied under pressure through the orifices of the application. 66. A food spreader and applicator: a container, having a closed end and an open end, capable of holding a spreadable food item such as cream cheese or whipped cream; and a wide applicator, mounted at the open end of the container, and having a plurality of angled orifices in fluid communication with the open end of the container such that the spreadable food item can flow through the orifices of the applicator. | CLAIM OF PRIORITY This application is a continuation in part of U.S. Ser. No. 10/628,097 filed Jul. 28, 2003 and U.S. Ser. No. 10/750,447 filed Dec. 30, 2003 and U.S. Ser. No. 10/810,485 filed Mar. 26, 2004. FIELD OF THE INVENTION The present invention relates to flowable material spreaders for use on hand manipulatable dispensers, and more particularly to spreaders at the nozzle ends of such dispensers. BACKGROUND OF THE INVENTION Spreadable foods are common table items and are enjoyed by many all over the world. There are numerous types of foods that can be spread. Typical spreadable foods include peanut butter, frosting, butter, mayonnaise, jelly, ice cream toppings, salad dressing and cream cheese and other edible spreads for use on bread, crackers, and the like. Often, a butter knife, spatula, or other similar device is used to spread the food onto the bread, cracker, or other item. However, these utensils can become lost on or at outdoor celebrations and picnics, or other events, or need to repeatedly dip a spreader knife into a jar. Additionally, material accumulates on the knife and jar edges, as well as crumbs of other materials can accumulate in the jar. A number of patents have issued related to food dispensers and the like. U.S. Pat. No. 5,377,874 discloses a liquid dispenser for dispensing fluid condiment materials, such as ketchup, mustard and mayonnaise as well as other liquids such as medicated salves, lotions and ointments. The dispenser includes a tubular body with a spherical plunger element connected to a spreader paddle member disposed within a tubular body. Upon external manipulation of the tubular body, the spherical plunger and spreader paddle arrangement is urged toward a dispenser nozzle for release of condiment filling contained therein. The sanitary spreader paddle simultaneously protrudes from within the tubular body as condiment filling is being evacuated. As a result, the user may evacuate the entire volume of condiment filling within the dispenser as well as spread the deposited condiment filling on a food article to be eaten. In a medical application of the invention, the dispenser includes an integral applicator swab which is connected to the spreader paddle and resides within the plunger. The spreader paddle is separated from the plunger to expose the cleansing swab for use on the body. U.S. Pat. No. 5,330,075 is directed to a food condiment dispenser for dispensing fluid condiment materials, such as ketchup, mustard and mayonnaise. The dispenser includes a tubular body with a spherical plunger element connected to a spreader paddle member disposed within a tubular body. Upon external manipulation of the tubular body, the spherical plunger and spreader paddle arrangement is urged toward a dispenser nozzle for release of condiment filling contained therein. The sanitary spreader paddle simultaneously protrudes from within the tubular body as condiment filling is being evacuated. As a result, the user may evacuate the entire volume of condiment filling within the dispenser as well as spread the deposited condiment filling on a food article to be eaten. U.S. Pat. No. 4,957,226 is directed to an automatic food dispensing method, apparatus and utensil primarily for use in fast food restaurants, bakeries, and the like. The method and apparatus comprise a pumping system from a supply through a pump in a controlled amount with a reverse action of the pump after the appropriate amount has been dispensed in order to avoid it dripping. Other drip proof arrangements, such as valving are also utilized optionally. The utensil comprises a handle attached to a container and spreading utensil such as a spoon, ladle, or the like, wherein predetermined portions of a food or substance used in a food may be dispensed either continually or as predetermined quantities. The device consists of a spoon or other appropriately shaped utensil attached to a hollow handle which terminates in a non-interfering connection with the interior of the utensil at one end and terminates at the other end in a connection to a food supply source. U.S. Pat. No. 6,153,238 is directed to a packaged cheese product comprising a hermetically sealed container, preferably a pouch, made out of flexible material; a decorator tip or adaptor therefore inside the container, a cheese product inside the container and a cap for closing the decorator tip when the pouch is partially emptied. The cheese product can be extruded after cuffing the corner off of the pouch and seating the decorator tip in the resulting opening. Cheese in decorative shapes can then be easily applied as a garnish on food items and the pouch can then be re-closed by capping the decorator tip. The cap preferably has a bulb member that fits inside the decorator tip and a skirt member that fits around the outside petals of the preferred decorator tip. U.S. Pat. No. 4,844,917 is directed to a cake frosting technique and assembly including a disposable frosting bag for home or commercial use to render the frosting or decorating of cakes or other pastries more convenient and expeditious by the complete elimination of the need for expensive and messy heretofore-used large commercial squeeze bags, or manually whipped and spread frosting, or expensive aerosols. The invention contemplates the ready coloring or tinting of the frosting to any desired hue within a wide range with any particular color and further contemplates the imparting of any desired flavoring to the frosting by the separate and conveniently associated provision of the aforesaid disposable bag containing a neutral or white frosting along with a plurality of separate color tint tubes and a plurality of separate flavor taste tubes, whose contents are to be admixed respectively with the base frosting material to achieve a desired blend for the ultimate decorative and taste effects contemplated. U.S. Patent Publication No. 2002/0000441 discloses an aperture forming structure, which when attached to or integrally formed in dispenser packages for flowable substances allows reclosure and single or multiple uses. The aperture forming structure includes a breakaway tip member of thermoformable plastic. The break away tip includes a hollow protrusion from a surface. The intersection of the hollow protrusion and the surface is a fault line. Rupturing of the fault line creates an aperture from which the contents of the dispenser package may exit. A cap may be integrally formed with the aperture forming structure and detached for protecting the hollow protrusion or for closing the aperture created when the fault line is ruptured. The aperture forming structure can be made by heating a relatively stiff substantially flat thermoformable sheet of and then stretching the sheet to create a first and a second hollow protrusion in a tiered configuration. A rupture line is placed at the intersection of the first and the second protrusions. The sheet may be attached to a pouch or containment member formed from a flexible sheet which contains any flowable substance. While there have been a number of prior systems directed to food spreaders, none have adequately addressed the need for ease of use and convenience. There is a need for a system to easily, quickly and accurately spread material such as edible substances, being dispensed from containers such as squeeze tubes or bottles. OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide a spreader that will allow a user to spread a spreadable food item. It is a further object of the present invention to provide a spreader having a dispensing nozzle associated with the dispenser to dispense said material, and a spreader surface associated with the nozzle whereby the dispenser may be manipulated to cause the spreader surface to spread material dispensed via the nozzle. It is a further object of the present invention to provide a system in which the spreader is flexible and can be viewed in use. It is a further object to provide a spreader in which the spreader is dome-shaped. It is a further object of the present invention to provide a spreader which has a number of orifices, having different shapes and configurations, including dome shapes. It is yet another object of the present invention to provide a spreader which includes expandable nipples. It is yet a further object of the present invention to provide a spreader, including a container, having a base and a lid opposite the base, the container capable of holding a spreadable food item; a detachable handle mounted on the container; a plunger, adapted to engage the detachable handle such that when the detachable handle is depressed, the plunger exerts pressure on the spreadable food item in the container; and a dispenser nozzle, mounted on the exterior of the container proximate to the base of the container, in fluid communication with the interior of the container such that the spreadable food item may be forced through the dispenser nozzle, the dispenser nozzle capable of being in a first position or a second position. In accordance with a first aspect of the present invention, a novel spreader is disclosed. The novel spreader includes a dispensing nozzle associated with the dispenser to dispense said material, and a spreader surface associated with the nozzle whereby the dispenser may be manipulated to cause the spreader surface to spread material dispensed via the nozzle. In accordance with another aspect of the present invention, a novel spreader is disclosed. The novel spreader includes a container, having a closed end and an open end, capable of holding a spreadable food item, and a nozzle, mounted at the open end of the container, and having an opening in fluid communication with the open end of the container such that the spreadable food item can flow through the opening of the nozzle. In accordance with yet another aspect of the present invention, a novel spreader/dispenser is disclosed. The novel spreader/dispenser includes a container, having a base and a lid opposite the base, the container capable of holding a spreadable food item; a detachable handle mounted on the container; a plunger, adapted to engage the detachable handle such that when the detachable handle is depressed, the plunger exerts pressure on the spreadable food item in the container; and a dispenser nozzle, mounted on the exterior of the container proximate to the base of the container, in fluid communication with the interior of the container such that the spreadable food item may be forced through the dispenser nozzle, the dispenser nozzle capable of being in a first position or a second position. The nozzles of the present invention can be used to spread a large variety of items in a variety of formats. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing summary, as well as the following detailed description of a preferred embodiment of the present invention will be better understood when read with reference to the appended drawings, wherein: FIG. 1 is a side elevation of a spreader in accordance with the present invention; FIG. 2 is a perspective top plan view of the FIG. 1 spreader; FIG. 3 is a front elevation of a spreader dispensing opening; FIG. 4 is a view like FIG. 2 but showing a spreader flexible dispensing nozzle; FIG. 4a is a spreader flexible dispensing nozzle having a wavy texture; FIG. 5 is a side elevation of a spreader nozzle; FIG. 6 is a top plan view of a spreader cap; FIG. 7 is a view of an entrance at the inlet end of a spreader as in FIG. 5; FIG. 8 is like FIG. 7, showing a different entrance configuration; FIG. 9 is a side elevation showing the end of a container to which a spreader cap attaches; FIG. 10 is a frontal view of the FIG. 9 container end; FIG. 11 is a side elevation showing a spreader or narrowed configuration; FIG. 12 is a side elevation of the discharge end of a container to which the FIG. 11 spreader attaches; FIG. 13 is a top plan view of a spreader discharge end, with a serrated edge; FIG. 14 is a view like FIG. 13 showing a nozzle discharge end with serrated edge; FIG. 15 is a side elevation showing a nozzle with a retracted movable spreader, and control; FIG. 16 is a view like FIG. 15, showing the movable spreader in extended position; FIG. 17 is like FIG. 15 but showing the movable retractable spreader at the underside of the nozzle; FIG. 18 is a top plan view of a nozzle with an associated retractable and extendable spreader; FIG. 19 shows a modified nozzle and spreader; FIG. 19a shows the FIG. 19 spreader in tilted position, for spreading use; FIG. 20 shows a curved flap or blade; FIG. 21a is a side elevation of an alternate embodiment of a spreader outfitted with a knife nozzle in accordance with the present invention; FIG. 21b is a side elevation of an alternate embodiment of a spreader outfitted with a spatula nozzle in accordance with the present invention; FIG. 22a is a front elevation view of an alternate embodiment of a spreader/dispenser in accordance with the present invention; FIG. 22b is a partial front elevation view of the spreader/dispenser of FIG. 22a in an alternate configuration; FIG. 23 is an exploded view of an alternate embodiment of a spreader and nozzle in accordance with the present invention; FIG. 24 is a front elevation view of an alternative embodiment of a spreader with nozzle and handle in accordance with the present invention; and FIG. 25 is a front elevation view of the spreader of FIG. 24 shown with a cap for the nozzle. FIG. 26 is a further alternative embodiment of a nozzle. FIG. 27 is still yet a further embodiment of the nozzle of the present invention. FIGS. 28a-28b are another embodiment of the nozzle spreader of the present invention. FIGS. 29 and 29b is another embodiment of the nozzle spreader of the present invention. FIG. 30 is another embodiment of the nozzle spreader of the present invention. FIGS. 31 and 31a are another embodiment of the nozzle spreader of the present invention. FIGS. 32a-32c is yet another embodiment of the present invention which includes a dome-shaped configuration. FIGS. 33a and 33b illustrate the slit openings of the present invention. FIGS. 34a-34b illustrate yet another alternative embodiment in which the dome-shape application is inserted into the throat of the bottle. FIGS. 35a-35e are perspective views of caps which are over the dome of the present invention. FIGS. 36a and 36b illustrate another embodiment of a flange-shaped dome closure system for use in the present invention. FIGS. 37a through 37f illustrate a dial-type dome applicator/spreader in accordance with the present invention. FIG. 38 illustrates a dome having a plurality of orifices having different sizes. FIG. 39 illustrates an embodiment in which the dome is pyramid sloped. FIG. 40 illustrates an alternative nozzle embodiment of the present invention having a dome-shaped applicator. FIG. 41 illustrates alternative orifice embodiments. FIG. 42 illustrates a nipple-based embodiment for use in the preferred embodiment. FIG. 43 are views of nipple embodiments of the present invention. FIG. 44 is an embodiment of the invention in which the orifices are angled. FIGS. 45a and 45b illustrate another dial-type embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein like reference numerals refer to the same components across the several views and in particular to FIGS. 1 and 2, there is shown a spreader 10. The spreader 10 contains dispensable, flowable food material such as peanut butter, jelly or other such edibles. When the container is squeezed, the material flows through a nozzle 11 which tapers toward an outlet 12 which is elongated laterally, to provide a dispensed layer 13 of material of thickness 14 substantially less than its width 15. A flexible spreader 17 in the form of a flap or blade, or spatula, is provided at the nozzle exit, to face the layer 13 exiting from the nozzle, whereby the user can manipulate the spreader, and its undersurface, via container manipulation, to further spread or shape the dispensed layer 13. The flap or blade may be stiff or sufficiently flexible to shape the layer 13. Note its lateral length 19 is substantially greater than its width. The tip of the nozzle or blade should be flexible The nozzle 11 may be stiff or may be flexible as in FIG. 4 to assist flexing of the spreader during container manipulation to cause the spreader to shape the layer 13 deposited on a surface 21 or spread it only after it is dispensed. The latter may be a food surface such as on bread, or other substances. FIG. 3 shows the nozzle outlet 22, which has lateral width 22a substantially greater than its thickness 22b. The nozzle may be a cap on the container, or may be integral with the container. A snap-on or threaded fitting 24 connects the nozzle to the container, in FIG. 4. As shown in FIG. 4a, the extruded product can have a wavy texture. FIGS. 5 and 6 show a nozzle 32, tapering toward a narrowed exit 33 with a spreader flap or blade 34 overhanging that exit. The blade 34 is preferably flexible. FIG. 6 shows a cap 190 that receives the nozzle with snap-ring retention at 188 in a cap recess 188a of nozzle end 32a. Cap inner wall 189 forms a recess to receive the nozzle. A plug 192 on the cap plugs outlet 33. FIG. 7 shows the exit 33 as laterally, elongated with narrowed width or height. The nozzle entrance is seen at 34, in FIG. 8. FIG. 9 shows dispenser threads 36 to which the nozzle may threadably or otherwise attach. FIG. 10 shows in frontal view the annular end of the thread 36. See end opening 10a. FIG. 11 shows a flexible nozzle 40 that tapers toward an outlet 41, such as an elongated slit. The nozzle tip 40a serves as a spreader and preferably is positioned so that it can be seen when in use. The nozzle has a fitting 43 that threadably attaches to dispenser threads 44, as seen in FIG. 12. Nozzle may alternatively be positioned via a snap and release mechanism. FIG. 13 shows a spreader flap 46 that has a laterally elongated serrated edge 47 to engage the dispensed layer 48 being dispensed. As a result, the layer 48 has an attractive striated appearance. The nozzle can be waved laterally back and forth to produce wavy elongated striations on the dispensed layer surface. FIG. 14 shows similar serrations 50 on the end of a nozzle 40b. A flap 51 can be attached to the nozzle to overlie the serrations, or part of same. In FIG. 15, the flap or blade 60 is carried for adjustable movement, as by a carrier or adjuster 61 on the nozzle. A finger engagable protrusion 61a on the carrier is manipulated to move or slide the blade and carrier toward or away from the nozzle exit 41a, thereby to adjust the exposure of the blade to the dispensed material, to provide additional flexibility of use of the blade. Grooving 63 in the nozzle in the form of a threaded cap 63a, guides the adjuster. FIG. 16 shows the blade in extended forward position. The dispensing nozzle cavity appears at 64. FIG. 18 is a top plan view of the FIG. 16 adjuster. stature 17 shows the adjuster at the bottom side of the nozzle 93, having an exit 93a and pusher. The option of depositing the layer 113 without interference with the spreader flap or blade, is preserved. In FIG. 19 a spreader 110 blade or flap 110a carried at 111 by, and may be fixedly or releasably attached to or integral with, a nozzle 112. See bond zone at 111. The spreader and nozzle are shown being moved to the right. See arrow 125, and a layer of dispensable material 113 is deposited on substrate 126, via bore 112a of the nozzle. Material 113 is typically edible, and may consist, for example, of peanut butter, butter, frosting, mayonnaise, jam, jelly, soft cheese, or other edibles. In FIG. 19, the spreader 110 as supported is angled, relative to the nozzle or its bore, so that the spreader flap terminal 11a is sufficiently offset from the nozzle outlet 112a by a sufficient distance, that the terminal tip 110a does not engage the top 113a of the deposited layer 113, as during depositing of the layer. Terminal 110a may consist of an elastomer such as rubber. Outlet 112a may be laterally elongated as in FIG. 7. In FIG. 19a the nozzle is now further tilted, as at angle a, so that the spreader blade terminal tip 110a engages the surface of the layer 113, for spreading purposes. Terminal 110a is shown as arcuately flexed near the tip, to smoothly engage and spreadably deform surface 113a, as the nozzle is moved to the right, relative to 113. Note that the spreader body at 110c upwardly of terminal 110a is thickened so as not to flex, and so as to positively position the terminal 110a as it accurately wipes along surface 113a. Terminal 110a may or may not be flexible, but is preferably arcuately flexible to smooth and spread surface 113a, as the nozzle and supply container are manipulated. Body 110c tapers toward the tip or terminal. This construction, as shown, lends itself to ease of cleaning of interior surfaces 128, 129, and 130, as well as cleaning of the terminal. Note the greater than 90 degrees angularities of adjacent surfaces 128 and 129, and 129 and 130, avoiding small gaps. The spreader terminal at 110a may have elongated lateral length, of dimension substantially greater than the nozzle discharge opening dimension, as described above in other FIGURES, for engaging the widened surface area of 113, achieved during spreading. FIG. 20 shows a curved flap or blade to conform to curvature of an edible, such as a corn cob. See laterally elongated nozzle outlet 22 having narrowed width 22b. A downwardly concave spreader flap or blade 17a is shown as above the outlet 22, and of lateral elongation greater than outlet 22 lateral elongation, indicated at 22a. FIG. 21a shows an alternate embodiment of the present invention that combines a knife and a spreader 200. The spreader 200 includes a container 201, that can hold a spreadable food F, such as peanut butter, butter, cheese, and the like. In a preferred embodiment of the present invention, the container 201 is flexible so as to allow a user to squeeze the spreadable food F. A knife nozzle 210 is attached to an open end of the container 201, and has an opening 220 to allow the spreadable food F to be transferred from the container 201 to an item such as bread, crackers, and the like. The knife nozzle 210 can then be used to spread the spreadable food F as desired. FIG. 21b illustrates another embodiment of the present invention that combines a spatula and a spreader 200′. The spreader 200′ includes a container 201′, very similar to the container 201 above, that can hold a spreadable food F, such as peanut butter, butter, cheese, and the like. In a preferred embodiment of the present invention, the container 201′ is flexible so as to allow a user to squeeze the spreadable food F. A spatula nozzle 210′, which may be flexible, is attached to an open end of the container 201′, and has an opening 220′ to allow the spreadable food F to be transferred from the container 201′ to an item such as bread, crackers, and the like. The knife nozzle 210′ can then be used to spread the spreadable food F as desired. Referring now to FIGS. 22a and 22b, another embodiment of a spreader 300 is illustrated. The spreader 300 includes a container 301, having a base 302 and a lid 303, that can hold a spreadable food F, such as peanut butter, butter, cheese, and the like. A detachable handle 310 is mounted on the container 301 at an attachment point 312 for transport and storage, to allow the spreader 300 to have less of a profile and take up less room. A dispenser nozzle 320 is mounted on the exterior of the container 301 to allow for the spreadable food in the container to be pushed out and onto a receiving food, such as bread, crackers and the like. When the spreader 300 is to be used, the detachable handle 310 is detached from the attachment point 312 and is mounted at mounting point 311, where it comes into engagement with a plunger 315, located in the lid 303. Additionally, the dispenser nozzle 320 may be rotated up or down, or flipped up in order to facilitate dispensing or storage as the case may be. When the handle 310 is depressed in the direction of arrow ‘P’, then the handle 310 exerts downward pressure on the spreadable food in the container 301, and forces the spreadable food out of the dispenser nozzle 320, and onto the receiving food. The interior of the dispenser is beveled 313 to facilitate the removal of all material. While this embodiment has be described in the context of longitudinally thrust plunger, it is to be appreciated that other equivalent structures could fulfill this function. For example the plunger could be thrust downward by means of a screw activated compression mechanism. Illustrated in FIG. 23 is another embodiment of a spreader 400. The spreader 400 includes a container 401 and a nozzle 420. The container includes a threaded end 426 and is capable of receiving a bag 410, which in turn holds a spreadable food such as peanut butter, butter, cheese, frosting, and the like. The bag 410 may be omitted altogether. The bag 410 is flexible in a preferred embodiment of the present invention and can be folded over the threaded end 415 of the container 401. The nozzle 420 includes an opening 425 and a threaded end 426 which threadedly engages the threaded end 426 of the container 401 to secure the nozzle 420 to the container 401. Additionally, the bag 410 is then secured into place as the overlap portion is secured between the threaded end 426 of the nozzle 420 and the threaded end 426 of the container 401. Referring now to FIGS. 24 and 25, another embodiment of a spreader 500 is shown. The spreader 500 includes a container 501, and a wide nozzle 520. Disposed within the container 501 is a bag 540 that can hold a spreadable food F, such as peanut butter, butter, cheese, frosting, and the like. The wide nozzle 520 is mounted at an open end 526 of the container 501, and includes an opening 525. Mounted on the container 501, at the opposite end 527 is a handle 510. The handle 510 includes a plunger 515, such that when the handle 510 is depressed in the direction of arrow ‘Q’, the plunger 515 forces the spreadable food contained within the bag 540 out through the opening 525 of the wide nozzle 520 and onto a receiving food, such as bread, crackers, cake, and the like. Additionally, a cap 530, having a cavity 531 substantially in the shape of the wide nozzle 520, can be mounted on the container 501 at the wide nozzle 520 in order to allow the spreader 500 to be stored standing upright. FIG. 26 illustrates yet another embodiment of a nozzle in accordance with the present invention. In this embodiment, a rubber or flexible nozzle 600 is affixed to a threaded member 610 and extended coaxially thereto. The rubber/plastic nozzle 600 can function as a spreader. FIG. 27 is still a further embodiment of nozzles in accordance with the present invention. FIG. 27 illustrates a nozzle 700 which either may be stiff or comprise a member expandable in accordion style when pressure is applied. FIGS. 28a and 28b are still yet a further embodiment of a spreader in accordance with the present invention. In this embodiment, the spreader is a cylindrical casing 800 with an adjustable spine 802, connected to an adjustment mechanism 804 and nozzle 807 permit the flow of condiments such as spread dressing. It is to appreciated that the adjustment mechanism 804 may comprise a drive crew or other similar device to longitudinally move the nozzle 807. The nozzle 807 may have holes to permit the flow of material there through. When the adjustment mechanism, is 804 pulled upward the nozzle 807 pulls upward and permits the flow of material. When pressure is applied the nozzle extends stiffly outward. This embodiment is similar in its operation to a garden nozzle. In a modified embodiment shown in FIG. 28b, the mechanism can have two positions, “on” and “off” 806, 808. FIGS. 29 and 29a illustrate yet another nozzle spreader embodiment. In this embodiment, the nozzle spreader comprises a flat, wide nozzle 900 having a plurality of shaped holes 902. The nozzle can have a flip cap 904, for example, and may have a cap or closure which has protrusions 906 to cover the holes. This embodiment is ideal for salad dressings or the like. As shown in FIG. 29a, the bottle can have a threaded attachment 908 and adjuster 910 to adjust the flow of material. FIG. 30 is a related embodiment to that of FIG. 29. In this embodiment, the nozzle comprises a flat, wide nozzle 1000 that inserts on a wide flange top 1002. The nozzle has a plurality of holes 1004 which may be beveled outward. The number, shape and position of the holes can be varied. This embodiment is ideal, for example, for ice cream toppings and salad dressings and other viscous food products. In a preferred embodiment, this bottle is a unitary structure including the novel flange top. Finally, FIGS. 31 and 31a illustrate yet another nozzle embodiment. In this embodiment, the nozzle/spreader comprises a wide but narrow slit flange 1100 which is affixed to the bottle or tube 1101. The corners of the nozzle can be straight or cornered. This embodiment may include an internal support or stilt 1102 to prevent the nozzle from collapsing. In view of the foregoing disclosure, some advantages of the present invention can be seen. For example, a novel spreader has been disclosed. The novel spreader easily, quickly and accurately spreads material such as edible substances, being dispensed from containers such as squeeze tubes or bottles. Referring to FIGS. 32a to 32c, alternative embodiments of the spreader dispenser of this present invention for viscous materials, salad dressings, mustard, ketchup, taco sauce, ice cream toppings, syrups and other semi-liquid and squeezable products. As seen in FIGS. 32a and 32b, the invention includes a bottle of food product 1202 containing a dome-shaped spreader/applicator 1210. The dome-shaped spreader/applicator 1210 has an outer lip 1212 which snaps onto the container neck to hold it secure. The dome-shaped spreader 1210 has a plurality of apertures or orifices 1220 which are position angle outward so that the dispensed product spreads out evenly when applied. The dome application thus functions to spread out the food product in a wide array and with uniformity. The orifices 1220 of the dome 1210 can be straight (in line) (FIG. 32c) or may be dispensed over the body of the dome 1225. In one embodiment the dome-shaped spreader 1210 may have internal threads 1230, which enables the lid to securely attach to the top of the bottle by screwing it on, snapping it on, or alternatively by affixing it by any other mechanism or instrumentality. Referring to FIGS. 33a and 33b, the orifice's dome-shaped spreader 1220 may have slits 1229 or a plurality of cross-slits 1231 instead of fully open apertures or orifices. It is to be appreciated that the holes where the product emerges, can have a plurality of diameters or shapes and any geometric configuration. Referring to FIGS. 34a and 34b, an embodiment is illustrated in which the dome-shaped spreader/applicator 1210 is placed within the inside lip of the bottle 1240. The spreader/applicator is held in place by a number of mechanisms, including threads or snaps. The dome in this embodiment fits proximate to the bottle top and has an annular serrated ridge 1354 which fits on the inside of the bottle. The dome can also be screwed into the bottle or secured using a variety of mechanical attachment systems. FIGS. 35a-35e illustrate caps 1300 which fit over the dome-shaped spreader. The present invention displays a number of cap embodiments. As shown in FIG. 35a, a first cap embodiment comprises a dome-shaped nozzle cap which is attached by a living hinge 1318. It can also be separate from the bottle. As shown in FIG. 35e, the cap can comprise a male closure with matching prongs 1323 which cover over the orifices. This prevents clogging of the holes by dried product. FIGS. 36a to 36c illustrate an embodiment of the dome-shaped nozzle applicator 1360 which corresponds to the wide flange embodiment of FIG. 30. Here the oval-shaped applicator 1360 is dome-shaped and a corresponding cap is dome-shaped and is designed to fit on the bottle. The dome can fit inside or outside of the bottle as shown in FIGURES. Alternatively, the dome-shaped applicator 1360 can have slits, crosses or other aperture shapes 1362 as shown in FIG. 36c. FIGS. 37(a)-(f) illustrates yet a further embodiment of the present invention. In this embodiment the dome-shaped applicator has a rotating dial cover 1372 which permits the apertures or orifices 1220 to be selectively opened and closed. By rotating the dial in one direction the orifices are open and product can flow. When rotated in the other direction the orifices 1220 are closed. The orifices can have any shape, size or configuration. FIG. 38 illustrates a dome having a plurality of orifices having different shapes, sizes and orientation. The different sized orifices 1220 allow the passage of different sized chunks or pieces (e.g. “Thousand Island” salad dressing). FIG. 39 illustrates yet another embodiment of the invention in which the applicator has the shape of a flattened, four sided pyramid 1380 instead of a curved shape. Each side 1382 has a plurality of orifices 1384. It is to be noted that the pyramid embodiment can have more than four sides (e.g. 6,8, 10, etc.). The invention also suggests additional embodiments besides pyramid shapes. FIG. 40 is an embodiment which corresponds with the nozzle embodiment of FIG. 28. In this embodiment, the dome-shaped applicator is affixed to the end of the cylindrical nozzle casing and permits product to flow through the orifices 1220. Referring to FIGS. 41a to 41c, alternative orifice configurations are shown. The orifices can be indented 1390 into the bottle. They can also face or protrude outward 1394. They can be contiguous with the dome 1396. The strength and pliability of the plastic, impacts the types of food to be used and the amount of pressure that needs to be applied. Referring now to FIGS. 42a and 42b, a still further embodiment is shown and described. This embodiment comprises an applicator with a plurality of nipple openings 1400. The embodiment comprises a plurality of flexible nipple inserts 1410. The flexible nipple inserts 1410 are indented inwardly 1420 into the bottle and they are forced outwardly 1425 when the product is squeezed out. FIGS. 43a to 43e shows a number of dome-shaped embodiments which illustrate the use of nipples. The nipples are shown as having a cross or X-shaped orifices 1500 as well as slits 1510. The nipple embodiment can be utilized with any of the embodiments shown in FIGS. 1 to 31. FIG. 44 illustrates an embodiment of the present invention in which the orifices are angled 1520. This embodiment permits product to be dispensed in a wide variety of directions. Finally, FIGS. 45a and 45b illustrate another embodiment in which the applicator 1600 has two sets of orifices. A four-holed dial 1610 can then be rotationally affixed over the applicator 1620. When the dial is turned in a first direction, the large orifices 1630 align with the dial. When turned in a second direction, the small orifices 1635 align. A third position closes the orifices. This embodiment facilitates two levels of product application flow. While the preferred embodiment of the present invention has been described and illustrated, modifications may be made by one of ordinary skill in the art without departing from the scope and spirit of the invention as defined in the appended claims. For example, in a preferred embodiment of the present invention, the bags 410 and 540 may be polybags, however, the bags may be of any type known to one of ordinary skill in art. Additionally, the method of securing the nozzles to the containers has been described and illustrated as being via a threaded engagement. However, a skilled artisan may employ any appropriate means to attach the nozzles to the containers, such as, but not limited to, a snap connection or molded piece. In addition, while the invention has been principally described in the context of food, it is to be appreciated that the applicator and spreader of the present invention may be applicable to non-food products. Nonexclusive examples include caulks, pastes, glues and building materials and automotive products such as waxes, greases, etc. | <SOH> BACKGROUND OF THE INVENTION <EOH>Spreadable foods are common table items and are enjoyed by many all over the world. There are numerous types of foods that can be spread. Typical spreadable foods include peanut butter, frosting, butter, mayonnaise, jelly, ice cream toppings, salad dressing and cream cheese and other edible spreads for use on bread, crackers, and the like. Often, a butter knife, spatula, or other similar device is used to spread the food onto the bread, cracker, or other item. However, these utensils can become lost on or at outdoor celebrations and picnics, or other events, or need to repeatedly dip a spreader knife into a jar. Additionally, material accumulates on the knife and jar edges, as well as crumbs of other materials can accumulate in the jar. A number of patents have issued related to food dispensers and the like. U.S. Pat. No. 5,377,874 discloses a liquid dispenser for dispensing fluid condiment materials, such as ketchup, mustard and mayonnaise as well as other liquids such as medicated salves, lotions and ointments. The dispenser includes a tubular body with a spherical plunger element connected to a spreader paddle member disposed within a tubular body. Upon external manipulation of the tubular body, the spherical plunger and spreader paddle arrangement is urged toward a dispenser nozzle for release of condiment filling contained therein. The sanitary spreader paddle simultaneously protrudes from within the tubular body as condiment filling is being evacuated. As a result, the user may evacuate the entire volume of condiment filling within the dispenser as well as spread the deposited condiment filling on a food article to be eaten. In a medical application of the invention, the dispenser includes an integral applicator swab which is connected to the spreader paddle and resides within the plunger. The spreader paddle is separated from the plunger to expose the cleansing swab for use on the body. U.S. Pat. No. 5,330,075 is directed to a food condiment dispenser for dispensing fluid condiment materials, such as ketchup, mustard and mayonnaise. The dispenser includes a tubular body with a spherical plunger element connected to a spreader paddle member disposed within a tubular body. Upon external manipulation of the tubular body, the spherical plunger and spreader paddle arrangement is urged toward a dispenser nozzle for release of condiment filling contained therein. The sanitary spreader paddle simultaneously protrudes from within the tubular body as condiment filling is being evacuated. As a result, the user may evacuate the entire volume of condiment filling within the dispenser as well as spread the deposited condiment filling on a food article to be eaten. U.S. Pat. No. 4,957,226 is directed to an automatic food dispensing method, apparatus and utensil primarily for use in fast food restaurants, bakeries, and the like. The method and apparatus comprise a pumping system from a supply through a pump in a controlled amount with a reverse action of the pump after the appropriate amount has been dispensed in order to avoid it dripping. Other drip proof arrangements, such as valving are also utilized optionally. The utensil comprises a handle attached to a container and spreading utensil such as a spoon, ladle, or the like, wherein predetermined portions of a food or substance used in a food may be dispensed either continually or as predetermined quantities. The device consists of a spoon or other appropriately shaped utensil attached to a hollow handle which terminates in a non-interfering connection with the interior of the utensil at one end and terminates at the other end in a connection to a food supply source. U.S. Pat. No. 6,153,238 is directed to a packaged cheese product comprising a hermetically sealed container, preferably a pouch, made out of flexible material; a decorator tip or adaptor therefore inside the container, a cheese product inside the container and a cap for closing the decorator tip when the pouch is partially emptied. The cheese product can be extruded after cuffing the corner off of the pouch and seating the decorator tip in the resulting opening. Cheese in decorative shapes can then be easily applied as a garnish on food items and the pouch can then be re-closed by capping the decorator tip. The cap preferably has a bulb member that fits inside the decorator tip and a skirt member that fits around the outside petals of the preferred decorator tip. U.S. Pat. No. 4,844,917 is directed to a cake frosting technique and assembly including a disposable frosting bag for home or commercial use to render the frosting or decorating of cakes or other pastries more convenient and expeditious by the complete elimination of the need for expensive and messy heretofore-used large commercial squeeze bags, or manually whipped and spread frosting, or expensive aerosols. The invention contemplates the ready coloring or tinting of the frosting to any desired hue within a wide range with any particular color and further contemplates the imparting of any desired flavoring to the frosting by the separate and conveniently associated provision of the aforesaid disposable bag containing a neutral or white frosting along with a plurality of separate color tint tubes and a plurality of separate flavor taste tubes, whose contents are to be admixed respectively with the base frosting material to achieve a desired blend for the ultimate decorative and taste effects contemplated. U.S. Patent Publication No. 2002/0000441 discloses an aperture forming structure, which when attached to or integrally formed in dispenser packages for flowable substances allows reclosure and single or multiple uses. The aperture forming structure includes a breakaway tip member of thermoformable plastic. The break away tip includes a hollow protrusion from a surface. The intersection of the hollow protrusion and the surface is a fault line. Rupturing of the fault line creates an aperture from which the contents of the dispenser package may exit. A cap may be integrally formed with the aperture forming structure and detached for protecting the hollow protrusion or for closing the aperture created when the fault line is ruptured. The aperture forming structure can be made by heating a relatively stiff substantially flat thermoformable sheet of and then stretching the sheet to create a first and a second hollow protrusion in a tiered configuration. A rupture line is placed at the intersection of the first and the second protrusions. The sheet may be attached to a pouch or containment member formed from a flexible sheet which contains any flowable substance. While there have been a number of prior systems directed to food spreaders, none have adequately addressed the need for ease of use and convenience. There is a need for a system to easily, quickly and accurately spread material such as edible substances, being dispensed from containers such as squeeze tubes or bottles. | <SOH> OBJECTS AND SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide a spreader that will allow a user to spread a spreadable food item. It is a further object of the present invention to provide a spreader having a dispensing nozzle associated with the dispenser to dispense said material, and a spreader surface associated with the nozzle whereby the dispenser may be manipulated to cause the spreader surface to spread material dispensed via the nozzle. It is a further object of the present invention to provide a system in which the spreader is flexible and can be viewed in use. It is a further object to provide a spreader in which the spreader is dome-shaped. It is a further object of the present invention to provide a spreader which has a number of orifices, having different shapes and configurations, including dome shapes. It is yet another object of the present invention to provide a spreader which includes expandable nipples. It is yet a further object of the present invention to provide a spreader, including a container, having a base and a lid opposite the base, the container capable of holding a spreadable food item; a detachable handle mounted on the container; a plunger, adapted to engage the detachable handle such that when the detachable handle is depressed, the plunger exerts pressure on the spreadable food item in the container; and a dispenser nozzle, mounted on the exterior of the container proximate to the base of the container, in fluid communication with the interior of the container such that the spreadable food item may be forced through the dispenser nozzle, the dispenser nozzle capable of being in a first position or a second position. In accordance with a first aspect of the present invention, a novel spreader is disclosed. The novel spreader includes a dispensing nozzle associated with the dispenser to dispense said material, and a spreader surface associated with the nozzle whereby the dispenser may be manipulated to cause the spreader surface to spread material dispensed via the nozzle. In accordance with another aspect of the present invention, a novel spreader is disclosed. The novel spreader includes a container, having a closed end and an open end, capable of holding a spreadable food item, and a nozzle, mounted at the open end of the container, and having an opening in fluid communication with the open end of the container such that the spreadable food item can flow through the opening of the nozzle. In accordance with yet another aspect of the present invention, a novel spreader/dispenser is disclosed. The novel spreader/dispenser includes a container, having a base and a lid opposite the base, the container capable of holding a spreadable food item; a detachable handle mounted on the container; a plunger, adapted to engage the detachable handle such that when the detachable handle is depressed, the plunger exerts pressure on the spreadable food item in the container; and a dispenser nozzle, mounted on the exterior of the container proximate to the base of the container, in fluid communication with the interior of the container such that the spreadable food item may be forced through the dispenser nozzle, the dispenser nozzle capable of being in a first position or a second position. The nozzles of the present invention can be used to spread a large variety of items in a variety of formats. | 20040719 | 20080205 | 20050623 | 62225.0 | 1 | WALCZAK, DAVID J | SPREADER | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,894,445 | ACCEPTED | Method to maintain stability in a bi-directional amplifier | A method for controlling an adjustable gain in an amplifier having an output power level and an adjustable gain is disclosed. The method includes an enhancement to a conventional Automatic Gain Control (AGC) function that distinguishes between a signal caused by oscillation and a signal that actually appears in the amplifier's passband. The method also controls unwanted and out of control amplifier oscillation using an iterative correlation process. The method prevents gain “hunting” if the output signal level is near the “set point” of the maximum permitted output level by implementing some degree of Hysteresis. The correlation process is performed by tracking a specified number of alternating gain increase/decrease cycles. If in any cycle the gain is not changed, or is changed in the same direction as in the previous cycle, the correlator is reset and the process begins again. The value and/or length of the correlator is set to minimize false detection due to random signal inputs, while maintaining acceptable sensitivity to oscillation. | 1. A method for controlling an adjustable gain in an amplifier having an output power level and an adjustable gain, the method comprising the acts of: a) obtaining a present output power level from the amplifier (50); b) responsive to said act of obtaining the present output power level, comparing the present output power level to a maximum power level threshold (60); c) responsive to said act of comparing the obtained present output power level to said maximum power level threshold, reducing the gain of the amplifier if the present output power level is greater than the maximum power level threshold (70); d) responsive to said act of comparing the obtained present output power level to said maximum power level threshold determining that said present output power level is less than the maximum power level threshold, determining if the gain of the amplifier is at its maximum permissible setting (80); e) responsive to act (d) determining that the gain of the amplifier is at its maximum permissible setting, maintaining the amplifier gain unchanged (90); f) responsive to act (d) determining that the gain of the amplifier is less than its maximum permissible setting, determining if said amplifier output power level is below a low power threshold (100); g) responsive to act (f) determining that the output power of the amplifier is below a low power threshold, increasing the amplifier gain by a predetermined amount (110); h) responsive to act (f) determining that the output power of the amplifier is above a low power threshold, maintaining the amplifier gain unchanged (90); i) responsive to said acts of reducing, increasing, and maintaining the gain, evaluating one or more acts of reducing, increasing or maintaining amplifier gain against a pre-defined amplifier gain adjustment act pattern associated with amplifier oscillation (120); j) responsive to said act of evaluating, resetting a correlation counter if the evaluated one or more acts of reducing, increasing, and maintaining amplifier gain do not correspond to the pre-defined pattern (130); k) responsive to said act of evaluating, incrementing a correlation counter if the evaluated one or more acts of reducing, increasing, and maintaining amplifier gain correspond to the pre-defined pattern (140); l) responsive to said act of incrementing the correlation counter, determining if said correlation counter is equal to a maximum correlation counter value (150); and m) responsive to said act of determining if said correlation counter is equal to a correlation counter threshold, reducing the amplifier gain by a predetermined amount (160) and resetting the correlation counter (170). 2. A computer executable program carrying out the method of claim 1. 3. A machine readable computer program carrying out the method of claim 1. 4. The method of claim 1 wherein said pre-defined pattern is symmetric. 5. The method of claim 1 wherein said pre-defined pattern is asymmetric. | CROSS-REFERENCE TO RELATED APPLICATION This application claims priority from U.S. Provisional Patent Application No. 60/488,840, entitled “A Method to Maintain Stability in a Bi-directional Amplifier,” which was filed on Jul. 21, 2003. TECHNICAL FIELD OF THE INVENTION This invention relates to a method for detecting and controlling oscillation caused by inadequate isolation between antennas used with a bi-directional amplifier and more particularly, to a method for enhancing an Automatic Gain Control (AGC) function that distinguishes between a strong signal caused by oscillation and a strong signal that appears in a passband of the amplifier. DESCRIPTION OF THE RELATED ART Typically, an amplifier will oscillate when a sufficient component of its output is fed back to its input in phase. Generally, a situation in which the gain of the amplifier is greater than the loss between the antenna connections will bring about this condition. This situation is considered in the design of an oscillator. In the case of an amplifier used to enhance wireless signals, the amplifier is placed between a first antenna for receiving and transmitting the wireless signal from and to the wireless base station, and a second antenna for re-radiating the signals from the wireless base station to a wireless subscriber's device. A finite amount of signal will be “fed back” to the first antenna to complete this feedback loop, and may cause the amplifier to oscillate, generating undesired signals in one or both passbands. The oscillation condition may not be apparent to the user or installer; however, it may result in severe degradation of the communication system. In some cases, it can cause an RF channel to be taken out of service completely due to interference. Decreasing the gain of the amplifier below the level required for oscillation will cause the oscillation to cease. Some amplifiers known in the prior art temporarily increase their gain significantly above their nominal gain level and test for an overload condition, indicating oscillation. This procedure may be repeated at intervals, but will change the operating parameters of the wireless distribution system. In another implementation, a signal is generated in the amplifier and detected at the amplifier's input. However, this may cause interference and require additional circuitry to generate and detect this signal. In another common implementation, an output is fed back to an input at a specific amplitude and with a specific time delay, to cancel feedback signal(s) external to the amplifier. Attempts have been made in the prior art at power sensing at the input with a separate amplifier/detector, and imposing a “signature” on the signals, causing some degree of distortion. There are devices in the prior art that generate an in-band signal, which radiates unwanted RF energy, and require a matched detector to detect the level of the signal fed back to the amplifier input. Other devices in the prior art require a narrowband detector, and impose a signature on the repeated signal. Other devices rely on the timing of a specific air interface technology (GSM) to detect instability; however, it also completely switches off the RF path in the process. Another device in the prior art requires disconnecting the amplifier, which is intrusive. It requires a detector at the amplifier input, and it completely shuts the amplifier off if oscillation is detected. One method employed in the prior art imposes a specific characteristic on the output signal by amplitude modulating the gain of the amplifier with a unique “code” and employing a dedicated detector to determine the amplitude of the modulated signal at the input to the amplifier. Although it can detect levels of isolation above that required for oscillation in the presence of very strong signals, it requires costly dedicated circuitry and adds some degree of distortion to the outputs of the amplifier. Low-end products have limited their functionality to detecting an overload condition (e.g., power output above a preset threshold) and shutting the amplifier off for some period of time. This results in the amplifier being non-functional, thus failing to provide service in its coverage area. Further, it results in high-level oscillation occurring each time the amplifier attempts to recover, potentially degrading the operation of subscriber or infrastructure equipment. The present invention is directed to overcoming one or more of the problems or disadvantages set forth above and providing a method for satisfying needs that the prior art does not meet. It is important to note that the present invention is not intended to be limited to a system or method which must satisfy one or more of any stated objects or features of the invention. It is also important to note that the present invention is not limited to the preferred, exemplary, or primary embodiment(s) described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims. SUMMARY OF THE INVENTION The present invention features a low cost method of maintaining stability in a bi-directional amplifier. In one aspect of the present invention, this is performed entirely by software and adds no cost to the product. This feature is particularly relevant to the low end or low cost market to address concerns from wireless carriers that amplifiers installed with inadequate antenna isolation can oscillate in their licensed frequency range and potentially degrade their network. In another aspect of the invention, there is disclosed a method for detecting and controlling oscillation caused by inadequate isolation between antennas used with a bi-directional amplifier. The method includes the acts of enhancing an Automatic Gain Control (AGC) function for distinguishing between a strong signal caused by oscillation and a strong signal that actually appears in a passband of the amplifier. The response of the AGC function is characterized for each type of signal, and a correlation process is used to identify oscillation and initiate a responsive amplifier gain change to eliminate this undesirable condition. The method imposes no unique characteristics on, and causes no degradation to, the output signal. The present invention thus features a method for distinguishing between a strong signal caused by oscillation and a strong signal that appears in a passband of an amplifier. Specifically, the present invention features a method including the acts of monitoring output power from the amplifier and adjusting the gain of the amplifier to maintain the output power below a pre-set level. The present invention features the act of comparing the output power level to a maximum power threshold. In response to the comparison, the gain of the amplifier is reduced if the output power level is greater than the maximum power threshold, and maintained if it is determined that the gain is at its maximum permissible setting when the output power is below the maximum power threshold. The present invention also features increasing the gain if the output power level is below the lowest threshold. After determining whether or not a signal gain change will be accomplished, the present invention features the act of evaluating the reduced, increased, or maintained gain pattern against a pre-defined pattern associated with oscillation. The correlation counter is reset if one or more iterations of the acts of reducing, increasing, and maintaining gain generates a pattern that does not correspond to the pre-defined pattern, and the correlation counter is incremented if one or more iterations of the acts of reducing, increasing, and maintaining gain generate a pattern that correspond to the pre-defined pattern, thus indicating oscillation. Matching to in inexact pattern (e.g., 90% correlation over a specified interval) could also be used to detect oscillation. The maximum gain is reduced and the correlation counter is reset if a correlation threshold is reached. The present invention also features a method for detecting and controlling oscillation caused by inadequate isolation between antennas used with a bi-directional amplifier. Specifically, the present invention features the acts of measuring the output power of the amplifier; and based on the measurement, controlling the gain of the amplifier. The gain is correlated with a predetermined pattern indicative of oscillation in an amplifier; and the gain of the amplifier is changed accordingly to control oscillation. BRIEF DESCRIPTION OF THE DRAWINGS These, and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein: FIG. 1 is a diagram illustrating the result of the Hysteresis level of the correlation process and resultant output signal in accordance with the present invention; FIG. 2 is a diagram illustrating power output in the case of oscillation; and FIG. 3 is a flow chart of a method for determining if a signal in the amplifier is oscillation or a signal in a passband of the amplifier according to one aspect of the present invention. DESCRIPTION OF THE INVENTION The present invention features a method for detecting and controlling oscillation caused by inadequate isolation between antennas used with a bi-directional amplifier. The method features an Automatic Gain Control (AGC) function for distinguishing between a strong signal caused by oscillation and a strong signal that appears in a passband of the amplifier. The enhanced Automatic Gain Control (AGC) function or feature may be incorporated into various designs. Although the present invention will be described in terms of a software algorithm, this is not a limitation of the present invention as it can also be accomplished in hardware, firmware or combinations of two or more of hardware, software and firmware. The method features the acts of controlling the amplifier's gain (digital or analog attenuation) and accurately measuring output power of the amplifier. The act of controlling the amplifier's gain may be performed by a variable gain amplifier. The present invention features a method for differentiating between a very strong signal, which will cause the gain of the amplifier to be reduced to maintain linear operation of the amplifier, and oscillation of the amplifier. This function takes advantage of a key characteristic of oscillation: its amplitude is highly nonlinear with respect to the gain of the amplifier. Implementation of an AGC circuit using digital attenuators or variable gain amplifiers requires some degree of Hysteresis to prevent gain “hunting” if the output signal level is near the “set point” of the AGC (i.e., the maximum permitted output level). For example, in the preferred embodiment, an attenuation step size is 2 dB, FIG. 1. In alternative embodiments, the attenuation steps may be 1 dB or ½ dB. In the preferred embodiment, the AGC decreases the gain by 2 dB if the output level is above the AGC set point. The output level at which the gain is increased by 2 dB is called the Hysteresis level and must be carefully chosen. A typical level is 3 dB below the AGC set point. For example, if the AGC set point is +20 dBm, the Hysteresis level is approximately +17 dBm. That is, when gain has been reduced by the AGC and the output level falls below +17 dBm, the gain is increased by one step (e.g., 2 dB). In the case of a real input signal, this will result in a 2 dB increase in output level, which is still below the AGC set point. If a signal is caused by oscillation, the output level will change by significantly more than 2 dB when the gain or attenuation is changed by that amount. The result is that in the case of oscillation, the gain “hunting” process described above will occur. A point will be reached at which the amplifier output power level is above the AGC set point at one gain level, and below the Hysteresis level when the gain has been reduced by one step (e.g., 2 dB), FIG. 2. The result is that the AGC will alternately decrease and increase the gain of the amplifier. In wireless systems, there is a great degree of randomness in the sum of all signals present in the amplifier's passband, causing random increases and decreases of the amplifier's gain. The present invention features the acts of applying a correlation process as described below and evaluating the response of the AGC to the amplifier output signals. If the signal is caused by oscillation, the gain will alternately be decreased and increased. This activity is tracked or patterned over some number of AGC cycles and if no deviation from this alternating pattern is seen, the amplifier is considered to be oscillating. In the preferred embodiment, the activity is tracked for sixteen of the AGC cycles. The correlation process is performed by tracking a specified number of alternating AGC gain increase/decrease cycles. If in any AGC cycle, the gain is not changed, or is changed in the same direction as in the previous cycle, the correlator is reset and the process begins again. The length of the correlator is set to minimize false detection due to random signal inputs, while maintaining acceptable sensitivity to oscillation. Oscillation may take place in either the uplink or the downlink of a bi-directional amplifier, or both. Thus, the correlation process is continuously and separately performed in both directions. When oscillation is detected in either direction, the gain in both directions is reduced by an amount (e.g., 4 dB) below the level at which the oscillation output drops below the Hysteresis level. This is sufficient to stop oscillation, while maintaining usable gain. The amount by which the gain is reduced will vary, based on factors such as the available gain of the amplifier. The gain is reduced in both directions to maintain balance between the uplink and downlink in the communications system, and may not be appropriate in all cases. The pattern may be different than alternating up/down in some cases. For example, in the case of a fast attack/slow decay pattern, the pattern may be: down, up, up, up, down, up, up, up, down, etc. Such patterns can also be monitored and acted upon. An inexact match (e.g., 90% correlation over a specified interval) could also be used to identify oscillation. FIG. 3 illustrates the method of distinguishing between a strong signal caused by oscillation and a strong signal that actually appears in a passband of the amplifier Automatic Gain Control process according to one aspect of the present invention. The method includes the act of monitoring the output power and adjusting the gain of the amplifier to maintain the output power below a pre-set level. The output power level is read, act 50, from a power detector and compared, act 60, with the maximum power threshold. If the power is greater than the maximum power level threshold, the gain of the amplifier is reduced, act 70. If the output power is below the maximum power threshold, a determination of whether the gain setting is at its maximum permissible setting, act 80 is made. If the gain setting is at its maximum permissible setting, no change is made, act 90. If the gain setting is not at its maximum permissible setting, the output power level is compared with a lower threshold, act 100. If the output power level is below the low power threshold, the gain is increased, act 110. The action taken (e.g., reducing gain, increasing gain, or no change) is evaluated against the pre-defined pattern 120 associated with oscillation. If the action taken does not correspond to the predefined oscillation pattern, the correlation counter is reset, act 130, and the process begins again from the beginning. If the action taken corresponds to the next action in the pre-defined gain pattern, the correlation counter is incremented, act 140. If the correlation counter threshold is reached after incrementing the correlation counter, act 150, the maximum permissible gain setting is reduced, act 160, and the correlation counter is reset, act 170. A typical value of the correlation counter threshold is 16; however, this value could vary widely depending on the attack time and false activation rate desired. By reducing the maximum permissible gain setting and resetting the correlation counter, it maintains the gain of the amplifier below the level needed to sustain oscillation. The present invention is not intended to be limited to a system or method which must satisfy one or more of any stated or implied object or feature of the invention and is not limited to the preferred, exemplary, or primary embodiment(s) described herein. Modifications and substitutions by one ordinary skilled in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims. | <SOH> TECHNICAL FIELD OF THE INVENTION <EOH>This invention relates to a method for detecting and controlling oscillation caused by inadequate isolation between antennas used with a bi-directional amplifier and more particularly, to a method for enhancing an Automatic Gain Control (AGC) function that distinguishes between a strong signal caused by oscillation and a strong signal that appears in a passband of the amplifier. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention features a low cost method of maintaining stability in a bi-directional amplifier. In one aspect of the present invention, this is performed entirely by software and adds no cost to the product. This feature is particularly relevant to the low end or low cost market to address concerns from wireless carriers that amplifiers installed with inadequate antenna isolation can oscillate in their licensed frequency range and potentially degrade their network. In another aspect of the invention, there is disclosed a method for detecting and controlling oscillation caused by inadequate isolation between antennas used with a bi-directional amplifier. The method includes the acts of enhancing an Automatic Gain Control (AGC) function for distinguishing between a strong signal caused by oscillation and a strong signal that actually appears in a passband of the amplifier. The response of the AGC function is characterized for each type of signal, and a correlation process is used to identify oscillation and initiate a responsive amplifier gain change to eliminate this undesirable condition. The method imposes no unique characteristics on, and causes no degradation to, the output signal. The present invention thus features a method for distinguishing between a strong signal caused by oscillation and a strong signal that appears in a passband of an amplifier. Specifically, the present invention features a method including the acts of monitoring output power from the amplifier and adjusting the gain of the amplifier to maintain the output power below a pre-set level. The present invention features the act of comparing the output power level to a maximum power threshold. In response to the comparison, the gain of the amplifier is reduced if the output power level is greater than the maximum power threshold, and maintained if it is determined that the gain is at its maximum permissible setting when the output power is below the maximum power threshold. The present invention also features increasing the gain if the output power level is below the lowest threshold. After determining whether or not a signal gain change will be accomplished, the present invention features the act of evaluating the reduced, increased, or maintained gain pattern against a pre-defined pattern associated with oscillation. The correlation counter is reset if one or more iterations of the acts of reducing, increasing, and maintaining gain generates a pattern that does not correspond to the pre-defined pattern, and the correlation counter is incremented if one or more iterations of the acts of reducing, increasing, and maintaining gain generate a pattern that correspond to the pre-defined pattern, thus indicating oscillation. Matching to in inexact pattern (e.g., 90% correlation over a specified interval) could also be used to detect oscillation. The maximum gain is reduced and the correlation counter is reset if a correlation threshold is reached. The present invention also features a method for detecting and controlling oscillation caused by inadequate isolation between antennas used with a bi-directional amplifier. Specifically, the present invention features the acts of measuring the output power of the amplifier; and based on the measurement, controlling the gain of the amplifier. The gain is correlated with a predetermined pattern indicative of oscillation in an amplifier; and the gain of the amplifier is changed accordingly to control oscillation. | 20040719 | 20070807 | 20050127 | 67320.0 | 1 | NGUYEN, SIMON | METHOD TO MAINTAIN STABILITY IN A BI-DIRECTIONAL AMPLIFIER | SMALL | 0 | ACCEPTED | 2,004 |
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10,894,687 | ACCEPTED | Vehicular tool restraint apparatus | An apparatus is provided for securing tools with respect to a spare wheel for a vehicle. The apparatus includes a hub member that is adapted for selective securement to a central area of a spare wheel. At least one securement structure is provided on the hub member. At least one strap member is secured to the at least one securement structure. The at least one strap member is adjustable to at least partially define a variably sized opening and is configured to selectively secure at least one tool within the variably sized opening. | 1. An apparatus for securing tools with respect to a spare wheel for a vehicle, the apparatus comprising: a hub member, the hub member being adapted for selective securement to a central area of a spare wheel; at least one securement structure on the hub member; and at least one strap member secured to the at least one securement structure, the at least one strap member being adjustable to at least partially define a variably sized opening, the at least one strap member being configured to selectively secure at least one tool within the variably sized opening. 2. An apparatus as recited in claim 1 wherein the strap member cooperates with the hub member to define the variably sized opening. 3. An apparatus as recited in claim 1 wherein the strap member is configured to adjust the size of the variably sized opening to compressingly engage at least one tool within the variably sized opening. 4. An apparatus as recited in claim 1 wherein the at least one securement structure includes first and second securement structures, the at least one strap member includes first and second strap members each having first and second ends, the first end of the first strap member being secured to the first securement structure, the first end of the second strap member being secured to the second securement structure, and the second end of the first strap member being configured for selective interconnection with the second end of the second strap member. 5. The apparatus as recited in claim 4 further comprising a connector for selectively interconnecting the second ends of the first and second strap members. 6. An apparatus as recited in claim 1 wherein the at least one securement structure includes first and second securement structures, the at least one strap member includes a first strap member having a first end and second end, the first end being secured to the first securement structure, and the second end being configured for selective interconnection with the second securement structure. 7. An apparatus as recited in claim 1 wherein the at least one securement structure is integrally formed with the hub member. 8. An apparatus as recited in claim 1 wherein the at least one securement structure is directly on the hub member. 9. An apparatus as recited in claim 1 wherein the at least one strap member comprises at least one belt. 10. An apparatus as recited in claim 9 further comprising hook and loop fasteners attached to the at least one belt, wherein the hook and loop fasteners are configured to assist in facilitating securement by the belt of at least one tool within the variably sized opening. 11. An apparatus as recited in claim 1 wherein the hub member is adapted for selective securement to a central opening in the central area of a spare wheel. 12. In combination with a spare wheel for a vehicle, an apparatus for securing tools with respect to the spare wheel, comprising: a hub member, the hub member being adapted for selective securement to a central area of the spare wheel; at least one securement structure on the hub member; at least one tool; and at least one strap member secured to the at least one securement member, the at least one strap member being adjustable to at least partially define a variably sized opening, the at least one strap member being configured to selectively secure the at least one tool within the variably sized opening. 13. An apparatus as recited in claim 12 wherein the strap member cooperates with the hub member to define the variably sized opening. 14. An apparatus as recited in claim 12 wherein the strap member is configured to adjust the size of the variably sized opening to compressingly engage the at least one tool within the variably sized opening. 15. An apparatus as recited in claim 12 wherein the at least one securement structure includes first and second securement structures, the at least one strap member includes first and second strap members each having first and second ends, the first end of the first strap member being secured to the first securement structure, the first end of the second strap member being secured to the second securement structure, and the second end of the first strap member being configured for selective interconnection with the second end of the second strap member. 16. An apparatus as recited in claim 12 wherein the at least one securement structure includes first and second securement structures, the at least one strap member includes a first strap member having a first end and second end, the first end being secured to the first securement structure, and the second end being configured for selective interconnection with the second securement structure. 17. An apparatus as recited in claim 12 wherein the at least one securement structure is integrally formed with the hub member. 18. An apparatus as recited in claim 12 wherein the at least one strap member comprises at least one belt. 19. An apparatus as recited in claim 18 further comprising hook and loop fasteners attached to the at least one belt, wherein the hook and loop fasteners are configured to assist in facilitating securement by the belt of the at least one tool within the variably sized opening. 20. An apparatus as recited in claim 12 wherein the hub member is adapted for selective securement to a central opening in the central area of a spare wheel. 21. An apparatus as recited in claim 12 wherein the at least one tool comprises at least one of a jack, a lug nut wrench, a jack handle, and a pry bar. 22. An apparatus for securing tools with respect to a spare wheel for a vehicle, the apparatus comprising: a hub member, the hub member being adapted for selective association with a central area of a spare wheel; a first belt having a first end and a second end, the first end of the first belt being secured to the hub member at a first location; a second belt having a first end and a second end, the first end of the second belt being secured to the hub member at a second location; wherein the first and second belts are adjustable to at least partially define a variably sized opening in which at least one tool can be compressingly engaged, and the second end of the first belt is configured for selective interconnection with the second end of the second belt such that at least one tool can be selectively secured within the variably sized opening. 23. The apparatus as recited in claim 22 further comprising at least one of a connector and a hook and loop fastener arrangement for selectively interconnecting the second end of the first belt with the second end of the second belt. 24. The apparatus as recited in claim 22 wherein the first location is spaced from the second location. | TECHNICAL FIELD The present invention relates to an apparatus for securing tools with respect to a spare wheel for a vehicle. The apparatus includes a hub member and at least one strap member secured to the hub member. The strap member(s) can be selectively adjustable to at least partially define a variably sized opening in which one or more tools can be secured. BACKGROUND OF THE INVENTION It is typical for some wheeled vehicles, such as automobiles and trucks, to be provided with one or more tools. These tools can be used by an operator to remedy any of a variety of vehicular problems including but not limited to the removal of a defective wheel (e.g., having a flat tire) and the installation of a spare wheel. In particular, such tools might include a jack, a pry bar, a wrench, and a screwdriver. Effectively storing these tools in a vehicle can be difficult. In particular, unless the tools are restrained, they might move during vehicular travel, and may accordingly damage adjacent items, create annoying sounds, and/or become so displaced that they are no longer readily locatable or accessible to an operator. However, as such tools are typically not needed by an operator on a frequent basis, vehicular manufacturers might not wish to employ sophisticated, bulky, and/or expensive restraint arrangements. Accordingly, there is a need for a simple but effective tool storage apparatus that can selectively restrain one or more tools such that they are conveniently accessible to an operator. SUMMARY OF THE INVENTION It is an aspect of the present invention to provide a simple but effective tool storage apparatus that can selectively restrain one or more tools such that they are conveniently accessible to an operator. To achieve the foregoing and other aspects, and in accordance with the purposes of the present invention defined herein, apparatuses are provided herein for securing tools with respect to a spare wheel for a vehicle. In accordance with one exemplary embodiment of the present invention, an apparatus is provided for securing tools with respect to a spare wheel for a vehicle. The apparatus comprises a hub member that is adapted for selective securement to a central area of a spare wheel. At least one securement structure is provided on the hub member. At least one strap member is secured to the at least one securement structure. The at least one strap member is adjustable to at least partially define a variably sized opening. Also, the at least one strap member is configured to selectively secure at least one tool within the variably sized opening. In accordance with another exemplary embodiment of the present invention, an apparatus for securing tools with respect to a spare wheel for a vehicle is provided in combination with the spare wheel. The apparatus comprises a hub member that is adapted for selective securement to a central area of the spare wheel. At least one securement structure is provided on the hub member. At least one tool is provided. At least one strap member is secured to the at least one securement member. The at least one strap member is adjustable to at least partially define a variably sized opening. Also, the at least one strap member is configured to selectively secure the at least one tool within the variably sized opening. In accordance with yet another exemplary embodiment of the present invention, an apparatus is provided for securing tools with respect to a spare wheel for a vehicle. The apparatus comprises a hub member that is adapted for selective association with a central area of a spare wheel. A first belt has a first end and a second end. The first end of the first belt is secured to the hub member at a first location. A second belt has a first end and a second end. The first end of the second belt is secured to the hub member at a second location. The first and second belts are adjustable to at least partially define a variably sized opening in which at least one tool can be compressingly engaged. The second end of the first belt is configured for selective interconnection with the second end of the second belt such that at least one tool can be selectively secured within the variably sized opening. One advantage of the present invention is its provision of a simple but effective tool storage apparatus that can selectively restrain one or more tools such that they are conveniently accessible to an operator. Additional aspects, advantages and novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The aspects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed that the same will be better understood from the following description taken in conjunction with the accompanying drawings in which: FIG. 1 is a perspective view depicting a restraint apparatus in accordance with one exemplary embodiment of the present invention, wherein the restraint apparatus is shown with respect to a spare wheel, a bolt and a vehicular mounting base; FIG. 2 is a perspective view depicting the restraint apparatus of claim 1 in use to secure tools with respect to a vehicle's spare wheel; FIG. 3 is a cross-sectional view of the restraint apparatus, tools, bolt, spare wheel and vehicular mounting base of FIG. 3 taken along lines 3-3 in FIG. 2; FIG. 4 is a perspective view depicting a restraint apparatus in accordance with another exemplary embodiment of the present invention; FIG. 5 is a perspective view depicting a restraint apparatus in accordance with another exemplary embodiment of the present invention, wherein the restraint apparatus is shown with respect to a spare wheel, a nut and a vehicular mounting base; and FIG. 6 is a cross-sectional view depicting a restraint apparatus in accordance with yet another exemplary embodiment of the present invention, wherein the restraint apparatus is shown with respect to a spare wheel, a bolt and a vehicular mounting base. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS The present invention and its operation are hereinafter described in detail in connection with the views and examples of FIGS. 1-6, wherein like numbers indicate the same or corresponding elements throughout the views. Referring to FIG. 1, a spare wheel 10 is shown to include a peripheral area 12 and a central area 14. The peripheral area 12 is shown to be provided by a tire 16, which can either be solid or air-filled. The central area 14 is shown to include a rim 18 that can have multiple openings such as a central opening 20 for receiving a vehicle's hub, as well as one or more non-central openings. Some non-central openings (e.g., 22) can be configured to receive lug bolts for mounting the wheel 10 to a vehicle's hub, while other non-central openings (e.g., 23) might be provided within the rim 18 for aesthetic, structural or other reasons. FIG. 1 also depicts a mounting base 24 that is provided by a vehicle 30. The mounting base 24 provides a suitable location against which a vehicle's spare wheel 10 can be secured. The mounting base 24 can either be immovable with respect to the associated vehicle 30 (e.g., integral with the vehicle's unibody or frame), or moveable with respect to the associated vehicle 30 (e.g., as part of a sliding tray). Regardless of whether the mounting base 24 is moveable or immovable, it can be located in any of a variety of suitable locations upon a vehicle, and can assume any of a variety of specific configurations. For example, the mounting base 24 might be disposed beneath the floor of a vehicle's trunk (e.g., in a subjacent storage compartment) or might alternatively be disposed upon a vehicle's side wall or tailgate. In some embodiments such as that depicted in FIG. 1, a threaded aperture 90 can be provided by the mounting base 24. The spare wheel 10 can be positioned with respect to the mounting base 24 so that one of its apertures (e.g., 20, 22, 23) substantially aligns with the threaded aperture 90. A restraint apparatus 31 in accordance with the teachings of the present invention can then be positioned adjacent to the spare wheel 10. In one embodiment (e.g., as shown in FIGS. 1-3), the restraint apparatus 31 can be positioned such that an aperture 46 in the restraint apparatus 31 substantially aligns with one of the openings in the spare wheel 10 (e.g., central opening 20, or a non-central opening 22 or 23) and with the threaded aperture 90 in the mounting base 24. A bolt 27 having a threaded portion 26 and a bolt head 28 can then be oriented such that its threaded portion 26 is inserted through the aligned aperture 46, the opening 20, and the threaded aperture 90 in the mounting base 24. When tightened, the bolt head 28 can bear upon the restraint apparatus 31, and the restraint apparatus 31 can in turn bear against the spare wheel 10, such that both the restraint apparatus 31 and the spare wheel 10 are secured in a fixed position with respect to the mounting base 24. To remove the spare wheel 10 and the restraint apparatus 31 from this association with the mounting base 24, the bolt 27 need only be unscrewed from the threaded aperture 90. In some embodiments a washer might be provided between the bolt head 28 and the top surface 94 of the restraint apparatus 31. The restraint apparatus 31 can be configured to retain one or more tools with respect to the spare wheel 10. Such tools might include any of a variety of tools that might be used to facilitate the removal or installation of a vehicular tire, the raising/lowering of the vehicle, and/or other maintenance or repair to the vehicle. In particular, such tools might include one or more jacks (e.g., piston-type, screw-type, or scissor-type), jack handles, wrenches, pry bars, fire extinguishers, first aid kits, flashlights, radios, flares, reflector units, tire pumps, screwdrivers, hammers, pliers, spare parts kits (e.g., having fuses, light bulbs, etc.), fuel siphons, towels, tow straps, jumper cables, tie-downs, and/or any of a variety of other tools. In one specific embodiment, the tools secured by the restraint apparatus 31 can comprise at least one of a jack, a lug wrench, a jack handle, and a pry bar. By securing tools with respect to a stored spare vehicular wheel, the tools can be restrained from movement during vehicular travel such that they can be easily located by an operator when needed, and so that they will not cause noise or damage while stored during vehicular movement. One exemplary restraint apparatus 31 in accordance with the teachings of the present invention is depicted in FIGS. 1-3. This restraint apparatus 31 is shown to include a hub member 32 having a base portion 86 and a pedestal portion 92. The pedestal portion 92 includes a top surface 94 against which a bolt head (e.g., 28) can contact and bear upon (as previously discussed). The base portion 86 includes a bottom surface 88 that can contact the central area 14 of the spare wheel 10 and/or can interact with one or more openings in the central area 14 of the spare wheel 10 (e.g., when the hub member 32 is tightened against the rim 18 by bolt head 28). The base portion 86 might also include a lip 82 that is sized and configured to matingly interface an opening (e.g., central opening 20) in the central area 14 of the spare wheel 10, as shown for example in FIG. 3. Through use of this lip 82, the base portion 86 can snugly interface the central opening 20 of the rim 18. In the event that the spare wheel 10 is alternatively oriented such that the threaded portion 26 extends through a non-central opening (e.g., 22 or 23) of the rim 18, a restraint apparatus 31 in accordance with the teachings of the present invention might alternatively be configured (e.g., with a base and/or lip) to matingly interface such a non-central opening. In this manner, the hub member 32 can be adapted for selective securement to a central opening 20 or another opening (e.g., 22 or 23) in the central area 14 of a spare wheel 10. The restraint apparatus 31 depicted in FIGS. 1-3 is shown to include first and second securement structures 34, 36. The first and second securement structures 34, 36 are shown to be integrally formed with the hub member 32 and are shown as being provided directly on the hub member 32. However, it should be appreciated that the first and second securement structures 34, 36 might alternatively be provided separately from the hub member 32, but attached to the hub member 32 through use of fasteners, adhesives, and/or any of a variety of other connection techniques. It should be understood, however, that the first and second securement structures can assume any of a variety of specific configurations that can vary based upon the precise configuration of the hub member and of the strap members to be secured thereto. In the embodiment depicted in FIGS. 1-3, the first securement structure 34 provides a first location 38 at which a first end 74 of a first strap member 42 can be secured. Likewise, the second securement structure 36 provides a second location 40 at which a first end 78 of a second strap member 44 can be secured. In some embodiments, the first location 38 can be spaced from the second location 40, as shown for example in the embodiment of FIGS. 1-3. Suitable strap members can comprise any of a variety of known materials including belts, chains, straps, bungee cords, cables, and/or any of a variety of other sufficiently flexible items. However, in the examples depicted in FIGS. 1-4, the strap members are shown to comprise belts formed from fabric (e.g., nylon) webbing. Referring again to the restraint apparatus 31 depicted in FIGS. 1-3, the first end 74 of the first strap member 42 is shown to be secured to the first securement structure 34. In particular, the first end 74 is shown to partially wrap around a portion 75 of the first securement structure 34 and to then attach to itself (e.g., at a connection location 72) to maintain this wrapped securement. Connection location 72 might involve sewing, riveting, gluing, welding, and/or any of a variety of other connection techniques. A hook and loop fastener arrangement 50 is shown to be attached to the first strap member 42 adjacent to the second end 76 of the first strap member 42. The hook and loop fastener arrangement 50 is shown to include a hook portion 52 and a loop portion 54, whereby the first strap member 42 can be bent such that the hook portion 52 can selectively contact and engage the loop portion 54 (e.g., as shown in FIGS. 2-3). It should be appreciated that in alternative embodiments of the present invention, the hook portion 52 and loop portion 54 might be reversed, and/or the hook and loop arrangement 50 might be replaced by some other fastening system adjacent to the second end 76 of the first strap member 42. The first end 78 of the second strap member 44 is shown to be secured to the second securement structure 36. In particular, the first end 78 is shown to partially wrap around a portion 77 of the second securement structure 36 and to then attach to itself (e.g., at connection location 68) to maintain this wrapped securement. The second end 80 of the second strap member 44 is shown to be fastened with a connector 48. In particular, the second end 80 is shown to partially wrap around a portion 49 of the connector 48 and to then attach to itself (e.g., at connection location 70) to maintain this wrapped fastening. Connection locations 68 and 70 might involve sewing, riveting, gluing, welding, and/or any of a variety of other connection techniques. In use, one or more tools and/or spacers can then be held atop the hub member 32 while the strap members 42 and 44 are adjusted to at least partially define the variably sized opening 84 in which the tools and spacers are secured. To adjust the strap members 42 and 44, the second end 76 of the first strap member 42 can be wrapped at least partially around a portion 51 of the connector 48 and can then be adjusted (e.g., pulled tight) so that the variably sized opening 84 constricts to secure the tools and/or spacers within the variably sized opening 84. Once the variably sized opening 84 has been appropriately sized, a portion of the first strap member 42 that is associated with the hook portion 52 can then be pressed against a portion of the first strap member 42 that is associated with the loop portion 54, such that the hook portion 52 engages the loop portion 54. In this manner, the connector 48 selectively interconnects the second ends 76, 80 of the first and second strap members 42, 44, and the hook and loop fasteners are configured to assist in facilitating securement by the strap members 42, 44 of at least one tool within the variably sized opening 84. With the hook and loop fastener arrangement 50 engaged as discussed above, the first and second strap members 42 and 44 can maintain tools and/or spacers in a secured position within the variably sized opening 84 until such time as an operator later decides to access the tools. When the operator wishes to remove restrained tools from the variably sized opening 84, an operator need only disengage the hook portion 52 from the loop portion 54, and then allow the strap members 42, 44 to loosen such that the variably sized opening 84 sufficiently enlarges so as to free the tools. The first and second strap members 42 and 44 are accordingly adjustable such that they can cooperate with the hub member 32 to define the variably sized opening 84, and the strap members 42 and 44 are configured to adjust the size of the variably sized opening 84 to compressingly engage at least one tool therein. For example, as shown in FIGS. 2-3, such tools can include a jack 56, a wrench 58, and bars 60 and 62. Bars 60 and 62 might for example comprise handle extensions for the jack 56, and/or might comprise pry bars and/or other tools. Spacers 64 and 66 can be provided to separate the tools from contacting each other and from accordingly causing vibrations and/or other noise. Spacers can for example be formed from Styrofoam, wood, plastic, rubber and/or any other suitable material. Accordingly, the variably sized opening 84 can be suitable to receive any of a variety of tools in any of a variety of specific configurations, and the strap members 42, 44 can be used to secure those tools with respect to the hub member 32 and with respect to the mounting base 24 of the vehicle 30. Turning now to FIG. 4, another embodiment of a securing apparatus 131 in accordance with the teachings of the present invention is depicted. The securing apparatus 131 is shown to include a hub member 132 having a pedestal portion 192 and a base portion 186. The pedestal portion 192 is shown to include an aperture 146 for receiving a bolt for connection to a mounting base of a vehicle. The pedestal portion 192 is also shown to include a top surface 194 against which a securing bolt head can bear down. The base portion 186 can be configured to interface one or more openings in the central area of a spare wheel, and might include a lip or other structure to matingly interface a wheel rim. First and second securement structures 134, 136 are shown to be associated or integral with the base portion 186 of the hub member 132. A first strap member 142 is shown to have a first end 174 that is secured to the first securement structure 134 at a first location 138. In particular, the first end 174 is shown to partially wrap around a portion 175 of the first securement structure 134 and to then reattach to itself (e.g., at a connection location 168) to maintain this wrapped securement. The first strap member 142 is shown to comprise a belt formed from fabric (e.g., nylon), although it should be appreciated that the first strap member 142 can alternatively be formed differently and/or from any of a variety of other suitable materials (as discussed above with respect to strap members 42 and 44). After at least partially wrapping around any tools to be secured with respect to the spare wheel, the second end 176 of the strap member 142 can be secured to the second securement structure 136. In particular, the second end 176 can pass through an opening 179 in the second securement structure 136 and can then be adjusted (e.g., pulled tight) to restrict a variably sized opening 184 provided between the strap member 142 and the hub member 132. The second end 176 can then be attached to the strap member 142 adjacent to the second end 176 (e.g., through use of a hook and loop fastener arrangement 150 having a hook portion 152 associated with the second end 176 and a loop portion 154 associated with the strap member 142 in a location adjacent to the second end 176). In this manner, the second end 176 of the strap member 142 can be selectively interconnected with the second securement structure 136 at a second location 140, thereby providing an adjustable variably sized opening 184 for receiving and retaining tools. It should be appreciated that a bolt need not be provided to maintain a support apparatus in close association with a spare wheel. For example, as shown in FIG. 5, a mounting base 224 of a vehicle 230 is depicted as including a threaded rod 226. A spare wheel 210 having a central opening 220 can be positioned such that the central opening 220 passes over the threaded rod 226. A restraint apparatus 231 in accordance with the teaching of the present invention can have a hub member 232 that includes an aperture 246. The hub member 232 can be situated such that this aperture 246 passes over the threaded rod 226. A nut 228 or another securing device can then engage the end of the threaded rod 226, and can bear against a top surface 294 of the hub member 232 in order to hold the hub member 232 and the spare wheel 210 against the mounting base 224. Tools or other implements may then be secured with respect to the hub member 232 through use of one or more strap members. For example, as shown in FIG. 5, first and second strap members 242 and 244 can have first ends 274 and 278 that are attached to the hub member 232 at first and second securement structures 234 and 236, respectively. The second ends 276 and 280 of the first and second strap members 242 and 244 can then attach together through use of a connector 248 and a hook and loop fastener arrangement 250, for example. Although the threaded rod 226 is depicted in FIG. 5 as being vertically oriented, it should be appreciated that alternative mounting bases might be provided in which an associated threaded rod is substantially horizontally oriented. In another embodiment, a restraint apparatus in accordance with the present invention might itself incorporate a threaded aperture for engaging the threaded rod 226, and might accordingly itself operate to secure both itself and the spare wheel 210 with respect to the mounting base 224 of the vehicle 230. It should also be appreciated that other fasteners or interface devices might additionally or alternatively be provided to associate a restraint apparatus with a spare wheel in accordance with the present invention. A restraint apparatus in accordance with the teachings of the present invention can have any of a variety of different configurations, and can be associated with a spare wheel in any of a variety of specific manners or orientations. For example, a restraint apparatus 331 is shown in FIG. 6 to be similar to the restraint apparatus 31 of FIGS. 1-3, except that restraint apparatus 331 is shown to be associated with a spare wheel 310 in an inverted orientation as compared to the restraint apparatus 31 of FIGS. 1-3. This inverted orientation may be desirable when, for example, clearance space above a spare wheel is limited, when the spare wheel 310 is a full-size spare wheel (shown in FIG. 6) as opposed to the temporary-use spare wheel 10 (shown in FIGS. 1-3), and/or when a larger variably sized opening 384 is desired (e.g., for storage of larger and/or additional tools). The restraint apparatus of FIG. 6 is shown to include a hub member 332 and first and second strap members 342 and 344 attached to the hub member 332. The hub member 332 has a pedestal portion 392 and a base portion 386. The pedestal portion 392 can be inserted through a central opening 320 in the spare wheel 310, and the base portion 386 of the hub member 332 can then engage the rim 318 of the spare wheel 310 adjacent to the central opening 320, as shown in FIG. 6. A threaded portion 326 of a bolt 327 can then be inserted through an opening 346 in the pedestal portion 392, and can then be inserted into a threaded aperture 390 provided by a mounting base 324 of a vehicle 330. As the bolt 327 is threaded into the threaded aperture 390, a bolt head 328 associated with the bolt 327 engages the pedestal portion 392. As the bolt 327 is tightened, the restraint apparatus 331 and the spare wheel 310 are thereby secured in a fixed position with respect to the mounting base 324. Because the bolt head 328 may become recessed within a cavity formed by the pedestal portion 392 (e.g., as shown in FIG. 6), it may become difficult for an operator to use his or her fingers to turn the bolt head 328. For this reason, the bolt head 328 may be provided with knurls or other features to facilitate simpler engagement by an operator. Alternatively, the bolt head 328 might be configured to interact with one or more tools. For example, the bolt head 328 might be shaped like a lug nut so that the operator can use the lug nut wrench 358 to tighten or loosen the bolt 327. As another alternative, the bolt head 328 might include a slot or another such feature to facilitate interaction with a screwdriver or a pry bar. After the restraint apparatus 331 is secured with respect to the spare wheel 310 as discussed above, tools or other implements (e.g., tools 356, 358, 360 and 362, and spacers 364 and 366) may be secured within a variably sized opening 384 provided by one or more strap members. In the specific embodiment shown in FIG. 6, the variably sized opening 384 is formed by the first and second strap members 342 and 344 when they are attached together with a connector 348 and a hook and loop fastener arrangement 350. However, it should be appreciated that other strap member configurations might alternatively provide the variably sized opening 384 in which tools or other implements can be retained. The foregoing description of exemplary embodiments and examples of the invention has been presented for purposes of illustration and description. These examples and descriptions are not intended to be exhaustive or to limit the invention to the forms described. Numerous modifications are possible in light of the above teachings. Some of those modifications have been discussed, and others will be understood by those skilled in the art. It is hereby intended that the scope of the invention be defined by the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>It is typical for some wheeled vehicles, such as automobiles and trucks, to be provided with one or more tools. These tools can be used by an operator to remedy any of a variety of vehicular problems including but not limited to the removal of a defective wheel (e.g., having a flat tire) and the installation of a spare wheel. In particular, such tools might include a jack, a pry bar, a wrench, and a screwdriver. Effectively storing these tools in a vehicle can be difficult. In particular, unless the tools are restrained, they might move during vehicular travel, and may accordingly damage adjacent items, create annoying sounds, and/or become so displaced that they are no longer readily locatable or accessible to an operator. However, as such tools are typically not needed by an operator on a frequent basis, vehicular manufacturers might not wish to employ sophisticated, bulky, and/or expensive restraint arrangements. Accordingly, there is a need for a simple but effective tool storage apparatus that can selectively restrain one or more tools such that they are conveniently accessible to an operator. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an aspect of the present invention to provide a simple but effective tool storage apparatus that can selectively restrain one or more tools such that they are conveniently accessible to an operator. To achieve the foregoing and other aspects, and in accordance with the purposes of the present invention defined herein, apparatuses are provided herein for securing tools with respect to a spare wheel for a vehicle. In accordance with one exemplary embodiment of the present invention, an apparatus is provided for securing tools with respect to a spare wheel for a vehicle. The apparatus comprises a hub member that is adapted for selective securement to a central area of a spare wheel. At least one securement structure is provided on the hub member. At least one strap member is secured to the at least one securement structure. The at least one strap member is adjustable to at least partially define a variably sized opening. Also, the at least one strap member is configured to selectively secure at least one tool within the variably sized opening. In accordance with another exemplary embodiment of the present invention, an apparatus for securing tools with respect to a spare wheel for a vehicle is provided in combination with the spare wheel. The apparatus comprises a hub member that is adapted for selective securement to a central area of the spare wheel. At least one securement structure is provided on the hub member. At least one tool is provided. At least one strap member is secured to the at least one securement member. The at least one strap member is adjustable to at least partially define a variably sized opening. Also, the at least one strap member is configured to selectively secure the at least one tool within the variably sized opening. In accordance with yet another exemplary embodiment of the present invention, an apparatus is provided for securing tools with respect to a spare wheel for a vehicle. The apparatus comprises a hub member that is adapted for selective association with a central area of a spare wheel. A first belt has a first end and a second end. The first end of the first belt is secured to the hub member at a first location. A second belt has a first end and a second end. The first end of the second belt is secured to the hub member at a second location. The first and second belts are adjustable to at least partially define a variably sized opening in which at least one tool can be compressingly engaged. The second end of the first belt is configured for selective interconnection with the second end of the second belt such that at least one tool can be selectively secured within the variably sized opening. One advantage of the present invention is its provision of a simple but effective tool storage apparatus that can selectively restrain one or more tools such that they are conveniently accessible to an operator. Additional aspects, advantages and novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The aspects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. | 20040720 | 20100504 | 20060126 | 67321.0 | B62D4300 | 0 | LARSON, JUSTIN MATTHEW | VEHICULAR TOOL RESTRAINT APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | B62D | 2,004 |
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